The effect of treatment with Chinese medicine including Salvia miltiorrhizan and Astragalus, and the nonsteroid anti-inflammatory drug aspirin alone or combining radiotherapy, was investigated in 6-8 week-old TA2 mice...The effect of treatment with Chinese medicine including Salvia miltiorrhizan and Astragalus, and the nonsteroid anti-inflammatory drug aspirin alone or combining radiotherapy, was investigated in 6-8 week-old TA2 mice being inoculated mammary carcinoma. The date indicated the following conclusions: the tumor growth could be inhibited by aspirin alone (p<0.01) but Chinese medicine group was observed. Mice treated with radiotherapy together with medicine both Chinese medicine and aspirin, had a statistically significant tumor inhibiting (p<0.01) as compared to mice treated with radiotherapy alone. The function to prevent the normal tissues from radiation by these two medicine groups were observed simultaneously. In addition, blood-flow volume of microcirculation, immune function and lymphocyte micronucleus were examined, which were used to analyse potential mechanism of sensitizing enhancement for Chinese medicine and aspirin.展开更多
Colorectal cancer(CRC)remains a formidable global health challenge and is associated with dismal survival outcomes and high mortality among patients diagnosed at advanced stages.Despite advancements in early screening...Colorectal cancer(CRC)remains a formidable global health challenge and is associated with dismal survival outcomes and high mortality among patients diagnosed at advanced stages.Despite advancements in early screening and therapeutic interventions,the outcomes of patients with advanced-stage CRC remain suboptimal,as these patients continue to exhibit a persistently low 5-year survival rate.Palliative radiotherapy(RT)is crucial for advanced CRC patients,but radioresistance remains a significant clinical challenge.This resistance is attributed to multiple mechanisms,such as genetic heterogeneity,dysregulated DNA damage repair and tumor microenvironment metabolic disorders.Recent studies have shown that noncoding RNAs(ncRNAs),mainly microRNAs,long ncRNAs(lncRNAs)and circular RNAs,play pivotal roles in regulating CRC radiosensitivity through diverse mechanisms,such as epithelial-mesenchymal transition,epigenetic reprogramming,posttranscriptional regulation and oncogenic signaling pathway activation.For example,microRNAs such as miR-141-3p and miR-630 enhance CRC radiosensitivity by targeting oncogenic pathways.In addition,lncRNAs,including the lncRNAs HOTAIR and LINC00630,influence the radiosensitivity of CRC through interactions with the DNA damage repair machinery and epigenetic modulators,respectively.In addition,circ_0124554 acts as a competitive endogenous RNA to regulate oncogenic signaling.ncRNAs also serve as potential biomarkers for predicting radiosensitivity and prognosis.This review synthesizes the current evidence on the ncRNA-mediated regulatory networks that influence CRC radiosensitivity,emphasizing their potential as therapeutic targets to overcome RT resistance and improve outcomes in advanced CRC.By bridging mechanistic insights with clinical applications,this work aims to guide future research and the implementation of precision RT strategies.展开更多
Objective:To investigate the chemical components of Semen podocarpi extract(SPE)and its effect on nasopharyngeal carcinoma cells and CNE-2R cells.Methods:Chemical components in SPE were identified by UPLC-MS/MS.CCK-8 ...Objective:To investigate the chemical components of Semen podocarpi extract(SPE)and its effect on nasopharyngeal carcinoma cells and CNE-2R cells.Methods:Chemical components in SPE were identified by UPLC-MS/MS.CCK-8 and cell cloning experiments were applied to evaluate the effects of SPE on the proliferation of CNE-2R cells,and a single-hit multitarget model was used to calculate the radiobiological parameters.Cell apoptosis and cell cycle were analyzed by flow cytometry,and the levels of genes and proteins of the Raf/MEK/ERK pathway were determined by RT-PCR and Western blotting.Results:A total of 37 compounds from SPE were identified,and SPE with or without irradiation inhibited the proliferation of CNE-2R cells.SPE also promoted apoptosis,arrested cells in the G_(2)/M phase,and presented radiosensitizing effects.Compared with irradiation alone,the effects of SPE+irradiation on apoptosis and cell cycle distribution were not significantly different.In addition,SPE had no significant effect on MEK gene expression.SPE significantly increased the gene expression of C-Raf and significantly reduced the protein expression of C-Raf,as well as the gene and protein expression of ERK1 and ERK2.The protein levels of C-Raf,ERK1,and ERK2 were also significantly lower in cells treated with SPE+irradiation than in cells treated with irradiation alone.Conclusions:The effects of SPE on inhibiting cell proliferation and promoting apoptosis are likely associated with cell cycle arrest and Raf/MEK/ERK pathway regulation,and the mechanism underlying radiosensitization by SPE may involve downregulating the protein expression of C-Raf,ERK1,and ERK2.展开更多
It is of great significance to find safe and effective radiosensitizers.A primary investigation has been made on fisetin's modification of radiation effect,but its radiosensitization and related mechanisms still n...It is of great significance to find safe and effective radiosensitizers.A primary investigation has been made on fisetin's modification of radiation effect,but its radiosensitization and related mechanisms still need to be deeply clarified.Furthermore,fisetin with high hydrophobicity is difficult to dissolve in water,severely limiting its research and application.In this study,we fabricated a safe and soluble radiosensitizer fisetin micelle for precisely enhancing radiotherapy by inhibiting platelet-derived growth factor receptor-β(PDGFRβ)/signal transducer and activator of transcription 1(STAT1)/signal transducer and activator of transcription 3(STAT3)/B cell lymphoma 2(Bcl-2)signaling pathway in the tumor.Systematic and detailed studies were performed to verify its radiosensitization effect in vitro and in vivo.On the cellular level,fisetin micelles selectively increased the radiosensitivity of tumor cells(CT26 and 4T1 cells)and had little effect on the sensitivity of normal mouse cells(L929 cells)to radiation.In the mouse models of colon and breast cancers,fisetin micelles showed an efficient radiosensitization capacity without apparent toxicity.Additionally,we first found that fisetin micelles played a radiotherapy sensitization role by inhibiting the PDGFRβ/STAT1/STAT3/Bcl-2 pathway activity.In general,this work not only confirmed that fisetin micelles precisely exhibit a radiosensitization effect in vitro and in vivo,but also profoundly explored its mechanisms underlying,to provide a theoretical and experimental basis for the clinical application of fisetin micelles.展开更多
BACKGROUND Esophageal cancer(ESCA)poses a significant challenge in oncology because of the limited treatment options and poor prognosis.Therefore,enhancing the therapeutic effects of radiotherapy for ESCA and identify...BACKGROUND Esophageal cancer(ESCA)poses a significant challenge in oncology because of the limited treatment options and poor prognosis.Therefore,enhancing the therapeutic effects of radiotherapy for ESCA and identifying relevant therapeutic targets are crucial for improving both the survival rate and quality of life of patients.AIM To define the role of the transcription factor Snail family transcriptional repressor 1(SNAI1)in ESCA,particularly its regulation of radiosensitivity.METHODS A comprehensive analysis of TCGA data assessed SNAI1 expression in ESCA.Survival curves correlated SNAI1 levels with radiotherapy outcomes.Colony formation assays,flow cytometry,and a xenograft model were used to evaluate tumor radiosensitivity and apoptosis.Western blot validated protein expression,while Chromatin im-munoprecipitation assays examined SNAI1's role in regulating epithelial-mesenchymal transition(EMT).RESULTS SNAI1 expression in ESCA cell lines and clinical specimens emphasizes its central role in this disease.Elevated SNAI1 expression is correlated with unfavorable outcomes in radiotherapy.Downregulation of SNAI1 enhances the sensitivity of ESCA cells to ionizing radiation(IR),resulting in remarkable tumor regression upon IR treatment in vivo.This study underscores the direct involvement of SNAI1 in the regulation of EMT,particularly under IR-induced conditions.Furthermore,inhibiting deacetylation effectively suppresses EMT,suggesting a potential avenue to enhance the response to radiotherapy in ESCA.CONCLUSION This study highlights SNAI1's role in ESCA radiosensitivity,offering prognostic insights and therapeutic strategies to enhance radiotherapy by targeting SNAI1 and modulating EMT processes.展开更多
Objective: To detect the expression of cyclinD1 and Ki67 in nasopharyngeal carcinoma (NPC) and their correlation with the biological behaviors and prognosis. Methods: 56 cases of biopsy specimens ...Objective: To detect the expression of cyclinD1 and Ki67 in nasopharyngeal carcinoma (NPC) and their correlation with the biological behaviors and prognosis. Methods: 56 cases of biopsy specimens of NPC which had been embedded with para?n in 1996 in our hospital were collected and immunostained with cyclinD1 and Ki67 monoclonal antibodies by means of the streptavidin peroxides method. The patients were followed up periodically, and then their biological behaviors and prognosis were statistically analyzed. Results: The percentage of cyclinD1 and Ki67 positive cells in the NPC specimens ranged from 0–54% and 0–31% respectively. The staining was nuclear. Of the 56 cases, 30 cases (56.6%) highly expressed cyclinD1 or Ki67 HPI and 26 cases (46.4%) lowly expressed cyclinD1, while only 16 cases (28.6%) showed Ki67 HPI (high proliferated index) and 40 cases (71.4%) showed Ki67 LPI (low proliferated index). Patients who lowly expressed cyclinD1 or highly expressed Ki67 had a higher radiosensitivity and a better prognosis. Conclusion: CyclinD1 and Ki67 immunohistochemical staining is considered to be useful, not only as an independent factor of radiosensitivity and prognosis respectively, but also as a means of determining the optimum treatment for each individual patient with NPC.展开更多
Radiotherapy has played an important role in treatment of tumor patientssince it appeared about 80 years ago, and has been an indispensable part of the management of about50% of tumors (especially 60% - 70% of maligna...Radiotherapy has played an important role in treatment of tumor patientssince it appeared about 80 years ago, and has been an indispensable part of the management of about50% of tumors (especially 60% - 70% of malignant tumors). Currently, radiotherapy is used in simpleand palliative therapy, adjuvant therapy after or before surgery, simultaneous radio-chemotherapy,combined BRM (biological response modifier) therapy, ets. Radiosensitizing agents enhance theradiation effects on tumor cells so as to have better responses in radiotherapy. Tumor intrinsicradiosensitivity is affected by the hy-poxic level in solid tumor, the ability of the cells torepair the radiation-induced DNA damage, the number of cells which have a clonogenic capability toreestablish uncontrolled cell growth, the amount of dividing cells, and the distribution of cellsthroughout the cell cycle. Consequently , it is necessary and useful to add one or moreradiosensitizing agents in radiotherapy to increase the radio-sensitivity of tumor cells.展开更多
Ionizing radiation (IR) is the most common treatment used to control localized primary prostate cancer (PC). However, for a significant number of patients, radiotherapy fails to adequately control the tumor. Thus, a m...Ionizing radiation (IR) is the most common treatment used to control localized primary prostate cancer (PC). However, for a significant number of patients, radiotherapy fails to adequately control the tumor. Thus, a main clinical problem today is the lack of a specific marker that may be used to predict the treatment outcome and to identify prostate cancer patients who are unlikely to respond to radiation therapy. In this study, we used human PC xenografts with predetermined radioresistant/sensitive phenotypes, and gene expression microarrays, correlated their specific transcripttional profiles with response to radiation. Employing unsupervised two-way hierarchical clustering, we identified four gene clusters displaying different expression patterns. Two clusters showed higher expression levels in the resistant xenografts and the other two clusters showed higher expression levels in the sensitive xenografts. Expression levels of 113 genes differed by at least 3 fold between sensitive and resistant xenografts. These genes represent members of several cellular pathways, some of which are known to be associated with response to radiation. All or several of these genes could serve as predictive tools to determine at biopsy the expected response of a particular tumor to radiotherapy. Indeed, the profiles we identified enabled us to predict the degree of radiosensitivity of a panel of established PC cell lines. Importantly, irradiation of the PC xenografts did not induce any significant changes in gene expression, regardless of their susceptibility phenotype. These data strongly support the first of two models: a: a random effect of irradiation on a homogeneous population of cells, rather than b: of a tumor comprised of a mixture of radioresistant and radiosensitive cell subpopulations. Our findings imply that each of the radio-phenotypes represents different intrinsic characteristics that affect the ability of a tumor to survive radiotherapy.展开更多
BACKGROUND Esophageal cancer is one of the most common cancers around the world, and it has high incidence and mortality rates. The conventional therapy for esophageal cancer is radiotherapy, although its effect is hi...BACKGROUND Esophageal cancer is one of the most common cancers around the world, and it has high incidence and mortality rates. The conventional therapy for esophageal cancer is radiotherapy, although its effect is highly limited by the resistance of esophageal cancer cells. Thus, strong radiosensitizers can be very crucial during radiotherapy against esophageal cancer. Brucea javanica oil emulsion (BJOE) is a widely used drug against various cancers, such as liver, colon, and ovarian cancer. However, its anti-cancer effect and mechanism and the use of BJOE as a radiosensitizer have not been explored in esophageal cancer. AIM To evaluate the anti-cancer effect and mechanism of BJOE and explore the potential use of BJOE as a radiosensitizer during radiotherapy. METHODS The inhibitory effect of BJOE and its enhancement function with radiation on cell viability were examined with the calculated half-maximal effective concentration and half-maximal lethal concentration. The influence of BJOE on cell migration and invasion were measured with EC109 and JAR cells by wound-healing and transwell assay. Clonogenesis and apoptotic rate, which was measured by Hoechst staining, were investigated to confirm its enhancement function with radiation. To investigate the molecular pathway underlying the effect of BJOE, the expressions of several apoptosis- and cycle-related proteins was detected by western blotting.cell lines more than normal cell lines, and it markedly reduced migration and invasion in esophageal cancer cells (EC109 and JAR). Moreover, it promoted cell apoptosis and enhanced the effect of radiotherapy against esophageal cancerous cells. In the viability test, the values of half-maximal effective concentration and half-maximal lethal concentration were reduced. Compared to the control, only around 1/5 colonies formed when using BJOE and radiation together in the clonogenic assay. The apoptotic rate in EC109 was obviously promoted when BJOE was added during radiotherapy. Our study suggests that the expression of the apoptosis-proteins Bax and p21 were increased, while the expression of Bcl-2 was stable. Further detection of downstream proteins revealed that the expression of cyclin D1 and cyclin-dependent kinase 4/6 were significantly decreased. CONCLUSION BJOE has a strong anti-cancer effect on esophageal cancer and can be used as a radiosensitizer to promote apoptosis in cancerous esophageal cells via the cyclin D1-cyclin-dependent kinase 4/6 axis.展开更多
AIM:To investigate the radiation response of various human tumor cells and normal liver cells. METHODS: Cell lines of human hepatoma cells (SMMC-7721), liver cells (L02), melanoma cells (A375) and cervical tumor (HeLa...AIM:To investigate the radiation response of various human tumor cells and normal liver cells. METHODS: Cell lines of human hepatoma cells (SMMC-7721), liver cells (L02), melanoma cells (A375) and cervical tumor (HeLa) were irradiated with 60Co γ-rays. Cell survive was documented by a colony assay. Chromatid breaks were measured by counting the number of chromatid breaks and isochromatid breaks immediately after prematurely chromosome condensed by Calyculin-A. RESULTS: Linear quadratic survival curve was observed in all of four cell lines, and dose-dependent increase in radiation-induced chromatid and isochromatid breaks were observed in GB2B phase. Among these four cell lines, A375 was most sensitive to radiation, while, L02 had the lowest radiosensitivity. For normal liver cells, chromatid breaks were easy to be repaired, isochromatid breaks were difficult to be repaired. CONCLUSION: The results suggest that the y-rays induced chromatid breaks can be possibly used as a good predictor of radiosensitivity, also, unrejoined isochromatid breaks probably tightly related with cell cancerization.展开更多
AIM:To investigate whether the inhibition of autophagy by chloroquine(CQ)sensitizes rectal tumors to radiation therapy(RT)or concurrent chemoradiation(chemoRT).METHODS:In vitro,HCT-116 and HT-29 colorectal cancer(CRC)...AIM:To investigate whether the inhibition of autophagy by chloroquine(CQ)sensitizes rectal tumors to radiation therapy(RT)or concurrent chemoradiation(chemoRT).METHODS:In vitro,HCT-116 and HT-29 colorectal cancer(CRC)cell lines were treated as following:(1)PBS;(2)CQ;(3)5-fluorouracil(5-FU);(4)RT;(5)CQ and RT;(6)5-FU and RT;(7)CQ and 5-FU;and(8)5-FU and CQ and RT.Each group was then exposed to various doses of radiation(0-8 Gy)depending on the experiment.Cell viability and proliferative capacity were measured by3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)and clonogenic assays.Clonogenic survivalcurves were constructed and compared across treatment groups.Autophagy status was determined by assessing the LC3-Ⅱto LC3-Ⅰratio on western blot analysis,autophagosome formation on electron microscopy and identification of a perinuclear punctate pattern with GFPlabeled LC3 on fluorescence microscopy.Cell cycle arrest and cell death were evaluated by FACS and AnnexinⅤanalysis.All experiments were performed in triplicate and statistical analysis was performed by the student’s t test to compare means between treatment groups.RESULTS:RT(2-8 Gy)induced autophagy in HCT-116and HT-29 CRC cell lines at 4 and 6 h post-radiation,respectively,as measured by increasing LC3-Ⅱto LC3-Ⅰratio on western blot.Additionally,electron microscopy demonstrated autophagy induction in HT-29 cells24 h following irradiation at a dose of 8 Gy.Drug treatment with 5-FU(25μmol/L)induced autophagy and the combination of 5-FU and RT demonstrated synergism in autophagy induction.CQ(10μmol/L)alone and in combination with RT effectively inhibited autophagy and sensitized both HCT-116 and HT-29 cells to treatment with radiation(8 Gy;P<0.001 and 0.00001,respectively).Significant decrease in clonogenic survival was seen only in the HT-29 cell line,when CQ was combined with RT at doses of 2 and 8 Gy(P<0.5 and P=0.05,respectively).There were no differences in cell cycle progression or Annexin V staining upon CQ addition to RT.CONCLUSION:Autophagy inhibition by CQ increases CRC cell sensitivity to concurrent treatment with 5-FU and RT in vitro,suggesting that addition of CQ to chemoRT improves CRC treatment response.展开更多
Nasopharyngeal carcinoma(NPC) is a common head and neck malignancy. The incidence of NPC is higher in Southern China and Southeast Asia compared with Western countries. Given its high radiosensitivity, the standard tr...Nasopharyngeal carcinoma(NPC) is a common head and neck malignancy. The incidence of NPC is higher in Southern China and Southeast Asia compared with Western countries. Given its high radiosensitivity, the standard treatment for NPC is radiotherapy. However, radioresistance remains a serious obstacle to successful treatment. Radioresistance can cause local recurrence and distant metastases in some patients after treatment by radiation. Thus, special emphasis has been given to the discovery of effective radiosensitizers. This review aims to discuss the biomarkers, classified according to the main mechanisms of radiosensitization, which can enhance the sensitivity of NPC cells to ionizing radiation.展开更多
AIM:To explore the potential of β-elemene as a radiosensitizer for gastric cancer cells and the underlying mechanisms.METHODS:SGC7901,MKN45,MKN28,N87,and AGS human gastric cancer cell lines were used to screen for ra...AIM:To explore the potential of β-elemene as a radiosensitizer for gastric cancer cells and the underlying mechanisms.METHODS:SGC7901,MKN45,MKN28,N87,and AGS human gastric cancer cell lines were used to screen for radioresistant gastric cancer cell lines. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium(MTT) assay was used to determine the effects of β-elemene and IPA-3 on cell viability in MKN45 and SGC7901 gastric cancer cell lines. A clonogenic survival assay and annexin V-FITC/PI apoptosis detection assay were used to evaluate cellular radiosensitivity and radiation-induced cell death,respectively. A proteomic method,isobaric tags for relative and absolute quantitation(i TRAQ),was employed to screen the proteins regulated by β-elemene pretreatment prior to ionizing radiation(IR) in SGC7901 gastric cancer cell line. IPA-3 was used as a specific small molecule inhibitor of p21-activated protein kinase 1(Pak1) to target Pak1 signaling. Protein levels of PAK1IP1(p21-activated protein kinase-interacting protein 1),total Pak1(t-Pak1),phospho-Pak1(T423),phospho-ERK1/2( Thr202/Tyr204),and cleaved caspase-3(17 k Da) were assessed by western blotting.RESULTS:MKN45 and SGC7901 gastric cancer cell lines were relatively more resistant to IR. β-elemene pretreatment decreased clonogenic survival following IR in MKN45 and SGC7901 gastric cancer cell lines. Additionally,β-elemene pretreatment prior to IR increased radiation-induced cell death compared with IR alone in MKN45(10.4% ± 0.9% vs 34.8% ± 2.8%,P < 0.05) and SGC7901(11.6% ± 0.9% vs 46.7% ± 5.2%,P < 0.05) human gastric cancer cell lines,respectively,consistent with the level of cleaved caspase-3(17 k Da). Through i TRAQ analysis and western blot validation,we found that β-elemene upregulated PAK1IP1 and downregulated phospho-Pak1(T423) and phosphoERK1/2 in SGC7901 gastric cancer cells. IR increased the level of phospho-Pak1(T423). Pretreatment with β-elemene decreased radiation-induced Pak1 and ERK1/2 phosphorylation. Inhibition of Pak1 using IPA-3 decreased clonogenic survival following IR. In addition,IPA-3 increased radiation-induced cell death in MKN45(13.4% ± 0.3% vs 26.6% ± 1.0%,P < 0.05) and SGC7901(16.0% ± 0.6% vs 37.3% ± 1.7%,P < 0.05) gastric cancer cell lines,respectively,consistent with the level of cleaved caspase-3(17 k Da). Western blotting showed that IPA-3 decreased radiation-induced Pak1 and ERK1/2 phosphorylation.CONCLUSION:This is the first demonstration that β-elemene enhances radiosensitivity of gastric cancer cells,and that the mechanism involves inhibition of Pak1 signaling.展开更多
AIM: To investigate the killing effect and radiosensitization of double suicide gene mediated by adenovirus on colorectal carcinoma cells. METHODS: Colorectal carcinoma cell line SW480 was transfected with adenovirus ...AIM: To investigate the killing effect and radiosensitization of double suicide gene mediated by adenovirus on colorectal carcinoma cells. METHODS: Colorectal carcinoma cell line SW480 was transfected with adenovirus expression vector containing cytosine deaminase (CD) and thymidine kinase (TK) fusion gene. The expression of CD-TK fusion gene was detected by reverse transcriptase-polymerase chain reaction. The toxic effect of ganciclovir (GCV) and 5-fluorocytosine (5-FC) on infected cells was determined by MTT assay. The radiosensitization of double suicide gene was evaluated by clonogenic assay. RESULTS: After prodrugs were used, the survival rate of colorectal carcinoma cells was markedly decreased. When GCV and 5-FC were used in combination, the cytotoxicity and bystander effect were markedly superior to a single prodrug (X2 = 30.371, P<0.01). Both GCV and 5-FC could sensitize colorectal carcinoma cells to the toxic effect of radiation, and greater radiosensitization was achieved when both prodrug were used in combination. CONCLUSION: CD-TK double suicide gene can kill and radiosensitize colorectal carcinoma cells.展开更多
AIM:To enhance the radiosensitivity of human colon cancer cells by docetaxel. METHODS: Immunoliposomal docetaxel was prepared by coupling monoclonal antibody against carcinoembryonic antigen to cyanuric chloride at th...AIM:To enhance the radiosensitivity of human colon cancer cells by docetaxel. METHODS: Immunoliposomal docetaxel was prepared by coupling monoclonal antibody against carcinoembryonic antigen to cyanuric chloride at the PEG terminus of liposome. LoVo adenocarcinoma cell line was treated with immunoliposomal docetaxel or/and irradiation. MTT colorimetric assay was used to estimate cytotoxicity of immunoliposomal docetaxel and radiotoxicity. Cell cycle redistribution and apoptosis were determined with flow cytometry. Survivin expression in LoVo cells was verified by immunohistochemistry. D801 morphologic analysis system was used to semi-quantify immunohistochemical staining of survivin. RESULTS: Cytotoxicity was induced by immunoliposomal docetaxel alone in a dose-dependent manner. Immunoliposomal docetaxel yielded a cytotoxicity effect at a low dose of 2 nmol/L. With a single dose irradiation, the relative surviving fraction of LoVo cells showed a dose-dependent response, but there were no significant changes as radiation delivered from 4 to 8 Gy. Compared with liposomal docetaxel or single dose irradiation, strongly radiopotentiating effects of immunoliposomal docetaxel on LoVo cells were observed. A low dose of immunoliposomal docetaxel could yield sufficient radiosensitivity. Immunoliposomal docetaxel were achieved both specificity of the conjugated antibody and drug radiosensitization. Combined with radiation, immunoliposomal docetaxel significantly increased the percentage of G2/M cells and induced apoptosis, but significantly decreased the percentage of cells in G2/G1 and S phase by comparison with liposomal docetaxel. Immunohistochemical analysis showed that the brown stained survivin was mainly in cytoplasm of LoVo cells. Semi-quantitative analysis of the survivin immunostaining showed that the expression of survivin in LoVo cells under irradiation with immunoliposomal docetaxel was significantly decreased. CONCLUSION: Immunoliposomal docetaxel is strongly effective for target radiosensitation in LoVo colon carcinoma cells, and may offer the potential to improve local radiotherapy.展开更多
AIM:To investigate the regulative effect of miRNA(miR)-221 on colorectal carcinoma(CRC)cell radiosensitivity and the underlying mechanisms.METHODS:A human CRC-derived cell line was cultured conventionally and exposed ...AIM:To investigate the regulative effect of miRNA(miR)-221 on colorectal carcinoma(CRC)cell radiosensitivity and the underlying mechanisms.METHODS:A human CRC-derived cell line was cultured conventionally and exposed to different doses of X-rays(0,2,4,6 and 8 Gy).The total RNA and protein of the cells were extracted 24 h after irradiation,and the alteration of miR-221 and phosphatase and tensin homolog deleted on chromosome 10(PTEN)gene mRNA expression was detected by real-time reverse transcriptase polymerase chain reaction(PCR).The protein alteration of PTEN in the cells was detected by Western blotting.Caco2 cells were pretreated with or without anti-PTEN-siRNA prior to the addition of premiR-221 or anti-miR-221 using Lipofectamine 2000.Colony formation assay and flow cytometry analysis were used to measure the surviving cell fraction and the sensitizing enhancement ratio after irradiation.Ad-ditionally,PTEN 3′-untranslated region fragment was PCR amplified and inserted into a luciferase reporter plasmid.The luciferase reporter plasmid construct was then transfected into CRC cells together with premiR-221 or anti-miR-221,and the luciferase activity in the transfected cells was detected.RESULTS:The X-ray radiation dose had a significant effect on the expression of miR-221 and PTEN protein in human Caco2 cells in a dose-dependent manner.The miR-221 expression level improved gradually with the increase in irradiation dose,while the PTEN protein expression level reduced gradually.miR-221 expression was significantly reduced in the anti-miR-221 group compared with the pre-miR-221 and negative control groups(P<0.01).Anti-miR-221 upregulated expression of PTEN protein and enhanced the radiosensitivity of Caco2 cells(P<0.01).Moreover,the inhibitory effect was dramatically abolished by pretreatment with anti-PTEN-siRNA,suggesting that the enhancement of radiosensitivity was indeed mediated by PTEN.A significant increase of luciferase activity was detected in CRC cells that were cotransfected with the luciferase reporter plasmid construct and anti-miR-221(P<0.01).CONCLUSION:Anti-miR-221 can enhance the radiosensitivity of CRC cells by upregulating PTEN.展开更多
Breast cancer(BC) is the most common cancer among women worldwide. The aetiology and carcinogenesis of BC are not clearly defined, although genetic, hormonal, lifestyle and environmental risk factors have been establi...Breast cancer(BC) is the most common cancer among women worldwide. The aetiology and carcinogenesis of BC are not clearly defined, although genetic, hormonal, lifestyle and environmental risk factors have been established. The most common treatment for BC includes breast-conserving surgery followed by a standard radiotherapy(RT) regimen. However, radiation hypersensitivity and the occurrence of RT-induced toxicity in normal tissue may affect patients' treatment. The role of DNA repair in cancer has been extensively investigated, and an impaired DNA damage response may increase the risk of BC and individual radiosensitivity. Single nucleotide polymorphisms(SNPs) in DNA repair genes may alter protein function and modulate DNA repair efficiency, influencing the development of various cancers, including BC. SNPs in DNA repair genes have also been studied as potential predictive factors for the risk of RT-induced side effects. Here, we review the literature on the association between SNPs in base excision repair(BER) genes and BC risk. We focusedon X-ray repair cross complementing group 1(XRCC1), which plays a key role in BER, and on 8-oxoguanine DNA glycosylase 1, apurinic/apyrimidinic endonuclease 1 and poly(ADP-ribose) polymerase-1, which encode three important BER enzymes that interact with XRCC1. Although no association between SNPs and radiation toxicity has been validated thus far, we also report published studies on XRCC1 SNPs and variants in other BER genes and RT-induced side effects in BC patients, emphasising that large well-designed studies are needed to determine the genetic components of individual radiosensitivity.展开更多
AIM: To investigate the feasibility and efficacy of the combination of S-1 with gemcitabine followed by oral S-1 with concurrent radiotherapy (intensity modulated radiotherapy, IMRT) and maintenance therapy with S-1 f...AIM: To investigate the feasibility and efficacy of the combination of S-1 with gemcitabine followed by oral S-1 with concurrent radiotherapy (intensity modulated radiotherapy, IMRT) and maintenance therapy with S-1 for locally advanced pancreatic cancer.展开更多
AIM： To investigate the prediction value of radiosensitivity of hepatocarcinoma cells for apoptosis and rnicronucleus assay. METHODS： Clonogenic assay, flow cytometry, and CB micronuclei assay were used to survey th...AIM： To investigate the prediction value of radiosensitivity of hepatocarcinoma cells for apoptosis and rnicronucleus assay. METHODS： Clonogenic assay, flow cytometry, and CB micronuclei assay were used to survey the cell survival rate, radiation-induced apoptosis and rnicronucleus frequency of hepatocarcinorna cell lines SMMC-7721, HL-7702, and HepG2 after being irradiated by X-ray at the dosage ranging 0-8 Gy. RESULTS： After irradiation, there was a dose-effect relationship between rnicronucleus frequency and radiation dosage among the three cell lines （P〈0.05）. A positive relationship was observed between apoptosis and radiation dosage among the three cell lines. The HepG2 cells had a significant correlation （P〈0.05） but apoptosis incidence had a negative relationship with rnicronucleus frequency. There was a positive relationship between apoptosis and radiation dosage and the correlation between 5MMC-7721 and HL-7702 cell lines had a significant difference （P〈0.01）. After irradiation, a negative relationship between cell survival rate and radiation dosages was found among the three cell lines （P〈0.01）. There was a positive relationship between cell survival rate and rnicronucleus frequency （P〈0.01）. No correlation was observed between apoptosis and cell survival rate. CONCLUSION： The radiosensiUvity of hepatocarcinoma cells can be reflected by apoptosis and rnicronuclei. Detection of apoptosis and rnicronuclei could enhance the accuracy for predicting radiosensitivity.展开更多
AIM:To investigate the role of endoplasmic reticulum(ER) stress in cancer radiotherapy and its molecular mechanism.METHODS:Tunicamycin(TM) was applied to induce ER stress in human esophageal cancer cell line EC109,and...AIM:To investigate the role of endoplasmic reticulum(ER) stress in cancer radiotherapy and its molecular mechanism.METHODS:Tunicamycin(TM) was applied to induce ER stress in human esophageal cancer cell line EC109,and the radiosensitization effects were detected by acute cell death and clonogenic survival assay.Cell cycle arrest induced by TM was determined by flow cytometric analysis after the cellular DNA content was labeled with propidium iodide.Apoptosis of EC109 cells induced by TM was detected by annexin V staining and Western blotting of caspase-3 and its substrate poly ADP-ribose polymerase.Autophagic response was determined by acridine orange(AO) staining and Western blotting of microtubule-associated protein-1 light chain-3(LC3) and autophagy related gene 5(ATG5).In order to test the biological function of autophagy,specific inhibitor or Beclin-1 knockdown was used to inhibit autophagy,and its effect on cell apoptosis was thus detected.Additionally,involvement of the phosphatidylinositol-3 kinase(PI3K)/Akt/mammalian target of the rapamycin(mTOR) pathway was also detected by Western blotting.Finally,male nude mice inoculated subcutaneously with EC109 cells were used to confirm cell model observations.RESULTS:Our results showed that TM treatment enhanced cell death and reduced the colony survival fraction induced by ionizing radiation(IR),which suggested an obvious radiosensitization effect of TM.Moreover,TM and IR combination treatment led to a significant increase of G2/M phase and apoptotic cells,compared with IR alone.We also observed an increase of AO positive cells,and the protein level of LC3-II and ATG5 was induced by TM treatment,which suggested an autophagic response in EC109 cells.However,inhibition of autophagy by using a chemical inhibitor or Beclin-1 silencing led to increased cell apoptosis and decreased cell viability,which suggested a cytoprotective role of autophagy in stressed EC109 cells.Furthermore,TM treatment also activated mTORC1,and in turn reduced Akt phosphorylation,which suggested the PI3K/Akt/mTOR signal pathway was involved in the TM-induced autophagic response in EC109 cells.Tumor xenograft results also showed synergistic retarded tumor growth by TM treatment and IR,as well as the involvement of the PI3K/Akt/mTOR pathway.CONCLUSION:Our data showed that TM treatment sensitized human esophageal cancer cells to radiation via apoptosis and autophagy both in vitro and in vivo.展开更多
文摘The effect of treatment with Chinese medicine including Salvia miltiorrhizan and Astragalus, and the nonsteroid anti-inflammatory drug aspirin alone or combining radiotherapy, was investigated in 6-8 week-old TA2 mice being inoculated mammary carcinoma. The date indicated the following conclusions: the tumor growth could be inhibited by aspirin alone (p<0.01) but Chinese medicine group was observed. Mice treated with radiotherapy together with medicine both Chinese medicine and aspirin, had a statistically significant tumor inhibiting (p<0.01) as compared to mice treated with radiotherapy alone. The function to prevent the normal tissues from radiation by these two medicine groups were observed simultaneously. In addition, blood-flow volume of microcirculation, immune function and lymphocyte micronucleus were examined, which were used to analyse potential mechanism of sensitizing enhancement for Chinese medicine and aspirin.
文摘Colorectal cancer(CRC)remains a formidable global health challenge and is associated with dismal survival outcomes and high mortality among patients diagnosed at advanced stages.Despite advancements in early screening and therapeutic interventions,the outcomes of patients with advanced-stage CRC remain suboptimal,as these patients continue to exhibit a persistently low 5-year survival rate.Palliative radiotherapy(RT)is crucial for advanced CRC patients,but radioresistance remains a significant clinical challenge.This resistance is attributed to multiple mechanisms,such as genetic heterogeneity,dysregulated DNA damage repair and tumor microenvironment metabolic disorders.Recent studies have shown that noncoding RNAs(ncRNAs),mainly microRNAs,long ncRNAs(lncRNAs)and circular RNAs,play pivotal roles in regulating CRC radiosensitivity through diverse mechanisms,such as epithelial-mesenchymal transition,epigenetic reprogramming,posttranscriptional regulation and oncogenic signaling pathway activation.For example,microRNAs such as miR-141-3p and miR-630 enhance CRC radiosensitivity by targeting oncogenic pathways.In addition,lncRNAs,including the lncRNAs HOTAIR and LINC00630,influence the radiosensitivity of CRC through interactions with the DNA damage repair machinery and epigenetic modulators,respectively.In addition,circ_0124554 acts as a competitive endogenous RNA to regulate oncogenic signaling.ncRNAs also serve as potential biomarkers for predicting radiosensitivity and prognosis.This review synthesizes the current evidence on the ncRNA-mediated regulatory networks that influence CRC radiosensitivity,emphasizing their potential as therapeutic targets to overcome RT resistance and improve outcomes in advanced CRC.By bridging mechanistic insights with clinical applications,this work aims to guide future research and the implementation of precision RT strategies.
基金supported by the Project of Administration of Traditional Chinese Medicine of Guangxi Zhuang Autonomous Region(grant number GZSY22-69)the Middle/Young aged Teachers’Research Ability Improvement Project of Guangxi Higher Education(grant number 2024KY0120).
文摘Objective:To investigate the chemical components of Semen podocarpi extract(SPE)and its effect on nasopharyngeal carcinoma cells and CNE-2R cells.Methods:Chemical components in SPE were identified by UPLC-MS/MS.CCK-8 and cell cloning experiments were applied to evaluate the effects of SPE on the proliferation of CNE-2R cells,and a single-hit multitarget model was used to calculate the radiobiological parameters.Cell apoptosis and cell cycle were analyzed by flow cytometry,and the levels of genes and proteins of the Raf/MEK/ERK pathway were determined by RT-PCR and Western blotting.Results:A total of 37 compounds from SPE were identified,and SPE with or without irradiation inhibited the proliferation of CNE-2R cells.SPE also promoted apoptosis,arrested cells in the G_(2)/M phase,and presented radiosensitizing effects.Compared with irradiation alone,the effects of SPE+irradiation on apoptosis and cell cycle distribution were not significantly different.In addition,SPE had no significant effect on MEK gene expression.SPE significantly increased the gene expression of C-Raf and significantly reduced the protein expression of C-Raf,as well as the gene and protein expression of ERK1 and ERK2.The protein levels of C-Raf,ERK1,and ERK2 were also significantly lower in cells treated with SPE+irradiation than in cells treated with irradiation alone.Conclusions:The effects of SPE on inhibiting cell proliferation and promoting apoptosis are likely associated with cell cycle arrest and Raf/MEK/ERK pathway regulation,and the mechanism underlying radiosensitization by SPE may involve downregulating the protein expression of C-Raf,ERK1,and ERK2.
基金funded by a grant from Technology Project of Science and technology department of Sichuan province(No.2018SZ0021)。
文摘It is of great significance to find safe and effective radiosensitizers.A primary investigation has been made on fisetin's modification of radiation effect,but its radiosensitization and related mechanisms still need to be deeply clarified.Furthermore,fisetin with high hydrophobicity is difficult to dissolve in water,severely limiting its research and application.In this study,we fabricated a safe and soluble radiosensitizer fisetin micelle for precisely enhancing radiotherapy by inhibiting platelet-derived growth factor receptor-β(PDGFRβ)/signal transducer and activator of transcription 1(STAT1)/signal transducer and activator of transcription 3(STAT3)/B cell lymphoma 2(Bcl-2)signaling pathway in the tumor.Systematic and detailed studies were performed to verify its radiosensitization effect in vitro and in vivo.On the cellular level,fisetin micelles selectively increased the radiosensitivity of tumor cells(CT26 and 4T1 cells)and had little effect on the sensitivity of normal mouse cells(L929 cells)to radiation.In the mouse models of colon and breast cancers,fisetin micelles showed an efficient radiosensitization capacity without apparent toxicity.Additionally,we first found that fisetin micelles played a radiotherapy sensitization role by inhibiting the PDGFRβ/STAT1/STAT3/Bcl-2 pathway activity.In general,this work not only confirmed that fisetin micelles precisely exhibit a radiosensitization effect in vitro and in vivo,but also profoundly explored its mechanisms underlying,to provide a theoretical and experimental basis for the clinical application of fisetin micelles.
基金Supported by the National Key R&D Program of China,No.2022YFC2503700 and No.2022YFC2503703the National Health Commission Key Laboratory of Nuclear Technology Medical Transformation(Mianyang Central Hospital),No.2023HYX005.
文摘BACKGROUND Esophageal cancer(ESCA)poses a significant challenge in oncology because of the limited treatment options and poor prognosis.Therefore,enhancing the therapeutic effects of radiotherapy for ESCA and identifying relevant therapeutic targets are crucial for improving both the survival rate and quality of life of patients.AIM To define the role of the transcription factor Snail family transcriptional repressor 1(SNAI1)in ESCA,particularly its regulation of radiosensitivity.METHODS A comprehensive analysis of TCGA data assessed SNAI1 expression in ESCA.Survival curves correlated SNAI1 levels with radiotherapy outcomes.Colony formation assays,flow cytometry,and a xenograft model were used to evaluate tumor radiosensitivity and apoptosis.Western blot validated protein expression,while Chromatin im-munoprecipitation assays examined SNAI1's role in regulating epithelial-mesenchymal transition(EMT).RESULTS SNAI1 expression in ESCA cell lines and clinical specimens emphasizes its central role in this disease.Elevated SNAI1 expression is correlated with unfavorable outcomes in radiotherapy.Downregulation of SNAI1 enhances the sensitivity of ESCA cells to ionizing radiation(IR),resulting in remarkable tumor regression upon IR treatment in vivo.This study underscores the direct involvement of SNAI1 in the regulation of EMT,particularly under IR-induced conditions.Furthermore,inhibiting deacetylation effectively suppresses EMT,suggesting a potential avenue to enhance the response to radiotherapy in ESCA.CONCLUSION This study highlights SNAI1's role in ESCA radiosensitivity,offering prognostic insights and therapeutic strategies to enhance radiotherapy by targeting SNAI1 and modulating EMT processes.
文摘Objective: To detect the expression of cyclinD1 and Ki67 in nasopharyngeal carcinoma (NPC) and their correlation with the biological behaviors and prognosis. Methods: 56 cases of biopsy specimens of NPC which had been embedded with para?n in 1996 in our hospital were collected and immunostained with cyclinD1 and Ki67 monoclonal antibodies by means of the streptavidin peroxides method. The patients were followed up periodically, and then their biological behaviors and prognosis were statistically analyzed. Results: The percentage of cyclinD1 and Ki67 positive cells in the NPC specimens ranged from 0–54% and 0–31% respectively. The staining was nuclear. Of the 56 cases, 30 cases (56.6%) highly expressed cyclinD1 or Ki67 HPI and 26 cases (46.4%) lowly expressed cyclinD1, while only 16 cases (28.6%) showed Ki67 HPI (high proliferated index) and 40 cases (71.4%) showed Ki67 LPI (low proliferated index). Patients who lowly expressed cyclinD1 or highly expressed Ki67 had a higher radiosensitivity and a better prognosis. Conclusion: CyclinD1 and Ki67 immunohistochemical staining is considered to be useful, not only as an independent factor of radiosensitivity and prognosis respectively, but also as a means of determining the optimum treatment for each individual patient with NPC.
文摘Radiotherapy has played an important role in treatment of tumor patientssince it appeared about 80 years ago, and has been an indispensable part of the management of about50% of tumors (especially 60% - 70% of malignant tumors). Currently, radiotherapy is used in simpleand palliative therapy, adjuvant therapy after or before surgery, simultaneous radio-chemotherapy,combined BRM (biological response modifier) therapy, ets. Radiosensitizing agents enhance theradiation effects on tumor cells so as to have better responses in radiotherapy. Tumor intrinsicradiosensitivity is affected by the hy-poxic level in solid tumor, the ability of the cells torepair the radiation-induced DNA damage, the number of cells which have a clonogenic capability toreestablish uncontrolled cell growth, the amount of dividing cells, and the distribution of cellsthroughout the cell cycle. Consequently , it is necessary and useful to add one or moreradiosensitizing agents in radiotherapy to increase the radio-sensitivity of tumor cells.
文摘Ionizing radiation (IR) is the most common treatment used to control localized primary prostate cancer (PC). However, for a significant number of patients, radiotherapy fails to adequately control the tumor. Thus, a main clinical problem today is the lack of a specific marker that may be used to predict the treatment outcome and to identify prostate cancer patients who are unlikely to respond to radiation therapy. In this study, we used human PC xenografts with predetermined radioresistant/sensitive phenotypes, and gene expression microarrays, correlated their specific transcripttional profiles with response to radiation. Employing unsupervised two-way hierarchical clustering, we identified four gene clusters displaying different expression patterns. Two clusters showed higher expression levels in the resistant xenografts and the other two clusters showed higher expression levels in the sensitive xenografts. Expression levels of 113 genes differed by at least 3 fold between sensitive and resistant xenografts. These genes represent members of several cellular pathways, some of which are known to be associated with response to radiation. All or several of these genes could serve as predictive tools to determine at biopsy the expected response of a particular tumor to radiotherapy. Indeed, the profiles we identified enabled us to predict the degree of radiosensitivity of a panel of established PC cell lines. Importantly, irradiation of the PC xenografts did not induce any significant changes in gene expression, regardless of their susceptibility phenotype. These data strongly support the first of two models: a: a random effect of irradiation on a homogeneous population of cells, rather than b: of a tumor comprised of a mixture of radioresistant and radiosensitive cell subpopulations. Our findings imply that each of the radio-phenotypes represents different intrinsic characteristics that affect the ability of a tumor to survive radiotherapy.
文摘BACKGROUND Esophageal cancer is one of the most common cancers around the world, and it has high incidence and mortality rates. The conventional therapy for esophageal cancer is radiotherapy, although its effect is highly limited by the resistance of esophageal cancer cells. Thus, strong radiosensitizers can be very crucial during radiotherapy against esophageal cancer. Brucea javanica oil emulsion (BJOE) is a widely used drug against various cancers, such as liver, colon, and ovarian cancer. However, its anti-cancer effect and mechanism and the use of BJOE as a radiosensitizer have not been explored in esophageal cancer. AIM To evaluate the anti-cancer effect and mechanism of BJOE and explore the potential use of BJOE as a radiosensitizer during radiotherapy. METHODS The inhibitory effect of BJOE and its enhancement function with radiation on cell viability were examined with the calculated half-maximal effective concentration and half-maximal lethal concentration. The influence of BJOE on cell migration and invasion were measured with EC109 and JAR cells by wound-healing and transwell assay. Clonogenesis and apoptotic rate, which was measured by Hoechst staining, were investigated to confirm its enhancement function with radiation. To investigate the molecular pathway underlying the effect of BJOE, the expressions of several apoptosis- and cycle-related proteins was detected by western blotting.cell lines more than normal cell lines, and it markedly reduced migration and invasion in esophageal cancer cells (EC109 and JAR). Moreover, it promoted cell apoptosis and enhanced the effect of radiotherapy against esophageal cancerous cells. In the viability test, the values of half-maximal effective concentration and half-maximal lethal concentration were reduced. Compared to the control, only around 1/5 colonies formed when using BJOE and radiation together in the clonogenic assay. The apoptotic rate in EC109 was obviously promoted when BJOE was added during radiotherapy. Our study suggests that the expression of the apoptosis-proteins Bax and p21 were increased, while the expression of Bcl-2 was stable. Further detection of downstream proteins revealed that the expression of cyclin D1 and cyclin-dependent kinase 4/6 were significantly decreased. CONCLUSION BJOE has a strong anti-cancer effect on esophageal cancer and can be used as a radiosensitizer to promote apoptosis in cancerous esophageal cells via the cyclin D1-cyclin-dependent kinase 4/6 axis.
基金Supported by the National Natural Science Foundation of China, No. 10335050Ministry of Science and Technology of the People's Republic of China, No. 2003CCB00200
文摘AIM:To investigate the radiation response of various human tumor cells and normal liver cells. METHODS: Cell lines of human hepatoma cells (SMMC-7721), liver cells (L02), melanoma cells (A375) and cervical tumor (HeLa) were irradiated with 60Co γ-rays. Cell survive was documented by a colony assay. Chromatid breaks were measured by counting the number of chromatid breaks and isochromatid breaks immediately after prematurely chromosome condensed by Calyculin-A. RESULTS: Linear quadratic survival curve was observed in all of four cell lines, and dose-dependent increase in radiation-induced chromatid and isochromatid breaks were observed in GB2B phase. Among these four cell lines, A375 was most sensitive to radiation, while, L02 had the lowest radiosensitivity. For normal liver cells, chromatid breaks were easy to be repaired, isochromatid breaks were difficult to be repaired. CONCLUSION: The results suggest that the y-rays induced chromatid breaks can be possibly used as a good predictor of radiosensitivity, also, unrejoined isochromatid breaks probably tightly related with cell cancerization.
文摘AIM:To investigate whether the inhibition of autophagy by chloroquine(CQ)sensitizes rectal tumors to radiation therapy(RT)or concurrent chemoradiation(chemoRT).METHODS:In vitro,HCT-116 and HT-29 colorectal cancer(CRC)cell lines were treated as following:(1)PBS;(2)CQ;(3)5-fluorouracil(5-FU);(4)RT;(5)CQ and RT;(6)5-FU and RT;(7)CQ and 5-FU;and(8)5-FU and CQ and RT.Each group was then exposed to various doses of radiation(0-8 Gy)depending on the experiment.Cell viability and proliferative capacity were measured by3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)and clonogenic assays.Clonogenic survivalcurves were constructed and compared across treatment groups.Autophagy status was determined by assessing the LC3-Ⅱto LC3-Ⅰratio on western blot analysis,autophagosome formation on electron microscopy and identification of a perinuclear punctate pattern with GFPlabeled LC3 on fluorescence microscopy.Cell cycle arrest and cell death were evaluated by FACS and AnnexinⅤanalysis.All experiments were performed in triplicate and statistical analysis was performed by the student’s t test to compare means between treatment groups.RESULTS:RT(2-8 Gy)induced autophagy in HCT-116and HT-29 CRC cell lines at 4 and 6 h post-radiation,respectively,as measured by increasing LC3-Ⅱto LC3-Ⅰratio on western blot.Additionally,electron microscopy demonstrated autophagy induction in HT-29 cells24 h following irradiation at a dose of 8 Gy.Drug treatment with 5-FU(25μmol/L)induced autophagy and the combination of 5-FU and RT demonstrated synergism in autophagy induction.CQ(10μmol/L)alone and in combination with RT effectively inhibited autophagy and sensitized both HCT-116 and HT-29 cells to treatment with radiation(8 Gy;P<0.001 and 0.00001,respectively).Significant decrease in clonogenic survival was seen only in the HT-29 cell line,when CQ was combined with RT at doses of 2 and 8 Gy(P<0.5 and P=0.05,respectively).There were no differences in cell cycle progression or Annexin V staining upon CQ addition to RT.CONCLUSION:Autophagy inhibition by CQ increases CRC cell sensitivity to concurrent treatment with 5-FU and RT in vitro,suggesting that addition of CQ to chemoRT improves CRC treatment response.
文摘Nasopharyngeal carcinoma(NPC) is a common head and neck malignancy. The incidence of NPC is higher in Southern China and Southeast Asia compared with Western countries. Given its high radiosensitivity, the standard treatment for NPC is radiotherapy. However, radioresistance remains a serious obstacle to successful treatment. Radioresistance can cause local recurrence and distant metastases in some patients after treatment by radiation. Thus, special emphasis has been given to the discovery of effective radiosensitizers. This review aims to discuss the biomarkers, classified according to the main mechanisms of radiosensitization, which can enhance the sensitivity of NPC cells to ionizing radiation.
基金Supported by National Nature Science Foundation of China,No.81172357
文摘AIM:To explore the potential of β-elemene as a radiosensitizer for gastric cancer cells and the underlying mechanisms.METHODS:SGC7901,MKN45,MKN28,N87,and AGS human gastric cancer cell lines were used to screen for radioresistant gastric cancer cell lines. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium(MTT) assay was used to determine the effects of β-elemene and IPA-3 on cell viability in MKN45 and SGC7901 gastric cancer cell lines. A clonogenic survival assay and annexin V-FITC/PI apoptosis detection assay were used to evaluate cellular radiosensitivity and radiation-induced cell death,respectively. A proteomic method,isobaric tags for relative and absolute quantitation(i TRAQ),was employed to screen the proteins regulated by β-elemene pretreatment prior to ionizing radiation(IR) in SGC7901 gastric cancer cell line. IPA-3 was used as a specific small molecule inhibitor of p21-activated protein kinase 1(Pak1) to target Pak1 signaling. Protein levels of PAK1IP1(p21-activated protein kinase-interacting protein 1),total Pak1(t-Pak1),phospho-Pak1(T423),phospho-ERK1/2( Thr202/Tyr204),and cleaved caspase-3(17 k Da) were assessed by western blotting.RESULTS:MKN45 and SGC7901 gastric cancer cell lines were relatively more resistant to IR. β-elemene pretreatment decreased clonogenic survival following IR in MKN45 and SGC7901 gastric cancer cell lines. Additionally,β-elemene pretreatment prior to IR increased radiation-induced cell death compared with IR alone in MKN45(10.4% ± 0.9% vs 34.8% ± 2.8%,P < 0.05) and SGC7901(11.6% ± 0.9% vs 46.7% ± 5.2%,P < 0.05) human gastric cancer cell lines,respectively,consistent with the level of cleaved caspase-3(17 k Da). Through i TRAQ analysis and western blot validation,we found that β-elemene upregulated PAK1IP1 and downregulated phospho-Pak1(T423) and phosphoERK1/2 in SGC7901 gastric cancer cells. IR increased the level of phospho-Pak1(T423). Pretreatment with β-elemene decreased radiation-induced Pak1 and ERK1/2 phosphorylation. Inhibition of Pak1 using IPA-3 decreased clonogenic survival following IR. In addition,IPA-3 increased radiation-induced cell death in MKN45(13.4% ± 0.3% vs 26.6% ± 1.0%,P < 0.05) and SGC7901(16.0% ± 0.6% vs 37.3% ± 1.7%,P < 0.05) gastric cancer cell lines,respectively,consistent with the level of cleaved caspase-3(17 k Da). Western blotting showed that IPA-3 decreased radiation-induced Pak1 and ERK1/2 phosphorylation.CONCLUSION:This is the first demonstration that β-elemene enhances radiosensitivity of gastric cancer cells,and that the mechanism involves inhibition of Pak1 signaling.
文摘AIM: To investigate the killing effect and radiosensitization of double suicide gene mediated by adenovirus on colorectal carcinoma cells. METHODS: Colorectal carcinoma cell line SW480 was transfected with adenovirus expression vector containing cytosine deaminase (CD) and thymidine kinase (TK) fusion gene. The expression of CD-TK fusion gene was detected by reverse transcriptase-polymerase chain reaction. The toxic effect of ganciclovir (GCV) and 5-fluorocytosine (5-FC) on infected cells was determined by MTT assay. The radiosensitization of double suicide gene was evaluated by clonogenic assay. RESULTS: After prodrugs were used, the survival rate of colorectal carcinoma cells was markedly decreased. When GCV and 5-FC were used in combination, the cytotoxicity and bystander effect were markedly superior to a single prodrug (X2 = 30.371, P<0.01). Both GCV and 5-FC could sensitize colorectal carcinoma cells to the toxic effect of radiation, and greater radiosensitization was achieved when both prodrug were used in combination. CONCLUSION: CD-TK double suicide gene can kill and radiosensitize colorectal carcinoma cells.
基金Supported by the Department of Science and Technology of Shandong Province
文摘AIM:To enhance the radiosensitivity of human colon cancer cells by docetaxel. METHODS: Immunoliposomal docetaxel was prepared by coupling monoclonal antibody against carcinoembryonic antigen to cyanuric chloride at the PEG terminus of liposome. LoVo adenocarcinoma cell line was treated with immunoliposomal docetaxel or/and irradiation. MTT colorimetric assay was used to estimate cytotoxicity of immunoliposomal docetaxel and radiotoxicity. Cell cycle redistribution and apoptosis were determined with flow cytometry. Survivin expression in LoVo cells was verified by immunohistochemistry. D801 morphologic analysis system was used to semi-quantify immunohistochemical staining of survivin. RESULTS: Cytotoxicity was induced by immunoliposomal docetaxel alone in a dose-dependent manner. Immunoliposomal docetaxel yielded a cytotoxicity effect at a low dose of 2 nmol/L. With a single dose irradiation, the relative surviving fraction of LoVo cells showed a dose-dependent response, but there were no significant changes as radiation delivered from 4 to 8 Gy. Compared with liposomal docetaxel or single dose irradiation, strongly radiopotentiating effects of immunoliposomal docetaxel on LoVo cells were observed. A low dose of immunoliposomal docetaxel could yield sufficient radiosensitivity. Immunoliposomal docetaxel were achieved both specificity of the conjugated antibody and drug radiosensitization. Combined with radiation, immunoliposomal docetaxel significantly increased the percentage of G2/M cells and induced apoptosis, but significantly decreased the percentage of cells in G2/G1 and S phase by comparison with liposomal docetaxel. Immunohistochemical analysis showed that the brown stained survivin was mainly in cytoplasm of LoVo cells. Semi-quantitative analysis of the survivin immunostaining showed that the expression of survivin in LoVo cells under irradiation with immunoliposomal docetaxel was significantly decreased. CONCLUSION: Immunoliposomal docetaxel is strongly effective for target radiosensitation in LoVo colon carcinoma cells, and may offer the potential to improve local radiotherapy.
基金Supported by National Natural Science Foundation of China,No.81101896the National Research Foundation for Doctoral Program of Higher Education of China,No.20124433110010
文摘AIM:To investigate the regulative effect of miRNA(miR)-221 on colorectal carcinoma(CRC)cell radiosensitivity and the underlying mechanisms.METHODS:A human CRC-derived cell line was cultured conventionally and exposed to different doses of X-rays(0,2,4,6 and 8 Gy).The total RNA and protein of the cells were extracted 24 h after irradiation,and the alteration of miR-221 and phosphatase and tensin homolog deleted on chromosome 10(PTEN)gene mRNA expression was detected by real-time reverse transcriptase polymerase chain reaction(PCR).The protein alteration of PTEN in the cells was detected by Western blotting.Caco2 cells were pretreated with or without anti-PTEN-siRNA prior to the addition of premiR-221 or anti-miR-221 using Lipofectamine 2000.Colony formation assay and flow cytometry analysis were used to measure the surviving cell fraction and the sensitizing enhancement ratio after irradiation.Ad-ditionally,PTEN 3′-untranslated region fragment was PCR amplified and inserted into a luciferase reporter plasmid.The luciferase reporter plasmid construct was then transfected into CRC cells together with premiR-221 or anti-miR-221,and the luciferase activity in the transfected cells was detected.RESULTS:The X-ray radiation dose had a significant effect on the expression of miR-221 and PTEN protein in human Caco2 cells in a dose-dependent manner.The miR-221 expression level improved gradually with the increase in irradiation dose,while the PTEN protein expression level reduced gradually.miR-221 expression was significantly reduced in the anti-miR-221 group compared with the pre-miR-221 and negative control groups(P<0.01).Anti-miR-221 upregulated expression of PTEN protein and enhanced the radiosensitivity of Caco2 cells(P<0.01).Moreover,the inhibitory effect was dramatically abolished by pretreatment with anti-PTEN-siRNA,suggesting that the enhancement of radiosensitivity was indeed mediated by PTEN.A significant increase of luciferase activity was detected in CRC cells that were cotransfected with the luciferase reporter plasmid construct and anti-miR-221(P<0.01).CONCLUSION:Anti-miR-221 can enhance the radiosensitivity of CRC cells by upregulating PTEN.
文摘Breast cancer(BC) is the most common cancer among women worldwide. The aetiology and carcinogenesis of BC are not clearly defined, although genetic, hormonal, lifestyle and environmental risk factors have been established. The most common treatment for BC includes breast-conserving surgery followed by a standard radiotherapy(RT) regimen. However, radiation hypersensitivity and the occurrence of RT-induced toxicity in normal tissue may affect patients' treatment. The role of DNA repair in cancer has been extensively investigated, and an impaired DNA damage response may increase the risk of BC and individual radiosensitivity. Single nucleotide polymorphisms(SNPs) in DNA repair genes may alter protein function and modulate DNA repair efficiency, influencing the development of various cancers, including BC. SNPs in DNA repair genes have also been studied as potential predictive factors for the risk of RT-induced side effects. Here, we review the literature on the association between SNPs in base excision repair(BER) genes and BC risk. We focusedon X-ray repair cross complementing group 1(XRCC1), which plays a key role in BER, and on 8-oxoguanine DNA glycosylase 1, apurinic/apyrimidinic endonuclease 1 and poly(ADP-ribose) polymerase-1, which encode three important BER enzymes that interact with XRCC1. Although no association between SNPs and radiation toxicity has been validated thus far, we also report published studies on XRCC1 SNPs and variants in other BER genes and RT-induced side effects in BC patients, emphasising that large well-designed studies are needed to determine the genetic components of individual radiosensitivity.
文摘AIM: To investigate the feasibility and efficacy of the combination of S-1 with gemcitabine followed by oral S-1 with concurrent radiotherapy (intensity modulated radiotherapy, IMRT) and maintenance therapy with S-1 for locally advanced pancreatic cancer.
文摘AIM： To investigate the prediction value of radiosensitivity of hepatocarcinoma cells for apoptosis and rnicronucleus assay. METHODS： Clonogenic assay, flow cytometry, and CB micronuclei assay were used to survey the cell survival rate, radiation-induced apoptosis and rnicronucleus frequency of hepatocarcinorna cell lines SMMC-7721, HL-7702, and HepG2 after being irradiated by X-ray at the dosage ranging 0-8 Gy. RESULTS： After irradiation, there was a dose-effect relationship between rnicronucleus frequency and radiation dosage among the three cell lines （P〈0.05）. A positive relationship was observed between apoptosis and radiation dosage among the three cell lines. The HepG2 cells had a significant correlation （P〈0.05） but apoptosis incidence had a negative relationship with rnicronucleus frequency. There was a positive relationship between apoptosis and radiation dosage and the correlation between 5MMC-7721 and HL-7702 cell lines had a significant difference （P〈0.01）. After irradiation, a negative relationship between cell survival rate and radiation dosages was found among the three cell lines （P〈0.01）. There was a positive relationship between cell survival rate and rnicronucleus frequency （P〈0.01）. No correlation was observed between apoptosis and cell survival rate. CONCLUSION： The radiosensiUvity of hepatocarcinoma cells can be reflected by apoptosis and rnicronuclei. Detection of apoptosis and rnicronuclei could enhance the accuracy for predicting radiosensitivity.
基金Supported by A Grant from the National Natural Science Foundation of China,No. 30870746
文摘AIM:To investigate the role of endoplasmic reticulum(ER) stress in cancer radiotherapy and its molecular mechanism.METHODS:Tunicamycin(TM) was applied to induce ER stress in human esophageal cancer cell line EC109,and the radiosensitization effects were detected by acute cell death and clonogenic survival assay.Cell cycle arrest induced by TM was determined by flow cytometric analysis after the cellular DNA content was labeled with propidium iodide.Apoptosis of EC109 cells induced by TM was detected by annexin V staining and Western blotting of caspase-3 and its substrate poly ADP-ribose polymerase.Autophagic response was determined by acridine orange(AO) staining and Western blotting of microtubule-associated protein-1 light chain-3(LC3) and autophagy related gene 5(ATG5).In order to test the biological function of autophagy,specific inhibitor or Beclin-1 knockdown was used to inhibit autophagy,and its effect on cell apoptosis was thus detected.Additionally,involvement of the phosphatidylinositol-3 kinase(PI3K)/Akt/mammalian target of the rapamycin(mTOR) pathway was also detected by Western blotting.Finally,male nude mice inoculated subcutaneously with EC109 cells were used to confirm cell model observations.RESULTS:Our results showed that TM treatment enhanced cell death and reduced the colony survival fraction induced by ionizing radiation(IR),which suggested an obvious radiosensitization effect of TM.Moreover,TM and IR combination treatment led to a significant increase of G2/M phase and apoptotic cells,compared with IR alone.We also observed an increase of AO positive cells,and the protein level of LC3-II and ATG5 was induced by TM treatment,which suggested an autophagic response in EC109 cells.However,inhibition of autophagy by using a chemical inhibitor or Beclin-1 silencing led to increased cell apoptosis and decreased cell viability,which suggested a cytoprotective role of autophagy in stressed EC109 cells.Furthermore,TM treatment also activated mTORC1,and in turn reduced Akt phosphorylation,which suggested the PI3K/Akt/mTOR signal pathway was involved in the TM-induced autophagic response in EC109 cells.Tumor xenograft results also showed synergistic retarded tumor growth by TM treatment and IR,as well as the involvement of the PI3K/Akt/mTOR pathway.CONCLUSION:Our data showed that TM treatment sensitized human esophageal cancer cells to radiation via apoptosis and autophagy both in vitro and in vivo.
