Summary: The expression and functional activity of multiple drug resistance (MDR1) gene in human normal bone marrow CD34+ cells was observed. Human normal bone marrow CD34+ cells were enriched with magnetic cell sorti...Summary: The expression and functional activity of multiple drug resistance (MDR1) gene in human normal bone marrow CD34+ cells was observed. Human normal bone marrow CD34+ cells were enriched with magnetic cell sorting (MACS) system, and then liposome-mediated MDR1 gene was transferred into bone marrow CD34+ cells. Fluorescence-activated cell sorter was used to evaluate the expression and functional activity of P-glycoprotein (P-gp) encoded by MDR1 gene. It was found that the purity of bone marrow CD34+ cells was approximately (91±4.56) % and recovery rate was (72.3±2.36) % by MACS. The expression of P-gp in the transfected CD34+cells was obviously higher than that in non-transfected CD34+ cells. The amount of P-gp in non-transfected CD34+ cells was (11.2±2.2) %, but increased to (23.6±2.34) % 48 h after gene transfection (P<0.0l). The amount of P-gp was gradually decreased to the basic level one week later. The accumulation and extrusion assays showed that the overexpression of P-gp could efflux Rh-123 out of cells and there was low fluorescence within the transfected cells. The functional activity of P-gp could be inhibited by 10 μg/ml verapamil. It was suggested that the transient and highly effective expression and functional activity of P-gp could be obtained by liposome-mediated MRD1 transferring into human normal bone marrow CD34+ cells.展开更多
AIM To observe the drug sensitizing effect andrelated mechanisms of fas gene transduction onhuman drug-resistant gastric cancer cellSGC7901/VCR(resistant to Vincristine).METHODS The cell cycle alteration wasobserved b...AIM To observe the drug sensitizing effect andrelated mechanisms of fas gene transduction onhuman drug-resistant gastric cancer cellSGC7901/VCR(resistant to Vincristine).METHODS The cell cycle alteration wasobserved by FACS.The sensitivity of gastriccancer cells to apoptosis was determined by invitro apoptosis assay.The drug sensitization ofcells to several anti-tumor drugs was observedby MTT assay.Immunochemical method wasused to show expression of P-gp and Topo Ⅱ ingastric cancer cells.RESULTS Comparing to SGC7901 and pBK-SGC7901/VCR,fas-SGC7901/VCR showeddecreasing G2 cells and increasing S cells,theG2 phase fraction of pBK-SGC7901/VCR wasabout 3.0 times that of fas-SGC7901/VCR,but Sphase fraction of fas-SGC7901/VCR was about1.9 times that of pBK-SGC7901/VCR,indicatingS phase arrest of fas-SGC7901/VCR.FACS alsosuggested apoptosis of fas-SGC7901/VCR,fas-SGC7901/VCR was more sensitive to apoptosisinducing agent VM-26 than pBK-SGC7901/VCR.MTT assay showed increased sensitization offas-SGC7901/VCR to DDP,MMC and 5-FU,butsame sensitization to VCR according to pBK-SGC7901/VCR.SGC7901,pBK-SGC7901/ VCRand fas-SGC7901/VCR had positively stainedTopo Ⅱ equally.P-gp staining in pBK- SGC7901/VCR was stronger than in SG07901,but there was little staining of P-gp in fas.SGC7901/VCR.CONCLUSION fas gene transduction couldreverse the MDR of human drug-resistant gastriccancer cell SGC7901/VCR to a degree,possiblybecause of higher sensitization to apoptosis anddecreased expression of P-gp.展开更多
Multiple myeloma(MM) is a cancer caused by uncontrolled proliferation of antibody-secreting plasma cells in bone marrow, which represents the second most common hematological malignancy. MM is a highly heterogeneous d...Multiple myeloma(MM) is a cancer caused by uncontrolled proliferation of antibody-secreting plasma cells in bone marrow, which represents the second most common hematological malignancy. MM is a highly heterogeneous disease and can be classified into a spectrum of subgroups based on their molecular and cytogenetic abnormalities. In the past decade, novel therapies, especially, the first-in-class proteasome inhibitor bortezomib, have been revolutionary for the treatment of MM patients. Despite these remarkable achievements, myeloma remains incurable with a high frequency of patients suffering from a relapse, due to drug resistance. Mutation in the proteasome β5-subunit(PSMB5) was found in a bortezomib-resistant cell line generated via long-term coculture with increasing concentrations of bortezomib in 2008, but their actual implication in drug resistance in the clinic has not been reported until recently. A recent study discovered four resistance-inducing PSMB5 mutations from a relapsed MM patient receiving prolonged bortezomib treatment. Analysis of the dynamic clonal evolution revealed that two subclones existed at the onset of disease, while the other two subclones were induced. Protein structural modeling and functional assays demonstrated that all four mutations impaired the binding of bortezomib to the 20 S proteasome, conferring different degrees of resistance. The authors further demonstrated two potential approaches to overcome drug resistance by using combination therapy for targeting proteolysis machinery independent of the 20 S proteasome.展开更多
The transforming growth factor(TGF)-βsignaling pathway controls many cellular processes,including proliferation,differentiation,and apoptosis.Abnormalities in the TGF-βsignaling pathway and its components are closel...The transforming growth factor(TGF)-βsignaling pathway controls many cellular processes,including proliferation,differentiation,and apoptosis.Abnormalities in the TGF-βsignaling pathway and its components are closely related to the occurrence of many human diseases,including cancer.Mothers against decapentaplegic homolog 4(Smad4),also known as deleted in pancreatic cancer locus 4,is a typical tumor suppressor candidate gene locating at q21.1 of human chromosome 18 and the common mediator of the TGF-β/Smad and bone morphogenetic protein/Smad signaling pathways.It is believed that Smad4 inactivation correlates with the development of tumors and stem cell fate decisions.Smad4 also interacts with cytokines,miRNAs,and other signaling pathways,jointly regulating cell behavior.However,the regulatory function of Smad4 in tumorigenesis,stem cells,and drug resistance is currently controversial.In addition,Smad4 represents an attractive therapeutic target for cancer.Elucidating the specific role of Smad4 is important for understanding the mechanism of tumorigenesis and cancer treatment.Here,we review the identification and characterization of Smad4,the canonical TGF-β/Smad pathway,as well as the multiple roles of Smad4 in tumorigenesis,stem cells,and drug resistance.Furthermore,we provide novel insights into the prospects of Smad4-targeted cancer therapy and the challenges that it will face in the future.展开更多
Drug resistance is becoming a great problem in developing countries due to excessive use and misuse of antibiotics. The emergence of new pathogenic strains with resistance developed against most of the antibiotics whi...Drug resistance is becoming a great problem in developing countries due to excessive use and misuse of antibiotics. The emergence of new pathogenic strains with resistance developed against most of the antibiotics which may cause,difficult to treat infection.To understand the current scenario in different mode of infection is most important for the clinicians and medical practitioners.This article summarized some common infections and antibiotic resistance pattern found among these pathogens.展开更多
Background:Breakpoint Cluster Region-Abelson(BCR::ABL1)fusion protein is essential in the pathogenesis of chronic myeloid leukemia(CML);however,the chronic-to-blast phase transformation remains elusive.We identified n...Background:Breakpoint Cluster Region-Abelson(BCR::ABL1)fusion protein is essential in the pathogenesis of chronic myeloid leukemia(CML);however,the chronic-to-blast phase transformation remains elusive.We identified novel kinesin light chain 2(KLC2)mutations in CML-myeloid blast phase patients.We aimed to examine the functional role of KLC2 mutations in leukemogenesis.Methods:To evaluate the biological role of KLC2 mutants(MT)in CML cells,we expressed KLC2-MT in different human CML cell lines harboring BCR::ABL1 and performed immunoblot,immunofluorescence,cell proliferation,differentiation,and apoptosis;Tyrosine kinase inhibitor(TKI)-drug activities;and clonogenic assays for in vitro functional analyses.We co-expressed KLC2-MT and BCR::ABL1 in mouse bone marrow cells(BMCs)to evaluate their clonogenic and self-renewal abilities ex vivo.Furthermore,we examined tumorigenic activity and drug efficacy in the K562 xenograft model.Results:KLC2-MT overexpression in BCR::ABL1-positive K562 and KU812 CML cells promoted cell proliferation and clonogenic potential,decreased imatinib sensitivity,and reduced apoptosis.Serial colony replating assays revealed that KLC2-MT and BCR::ABL1 co-expression enhanced the self-renewal ability of mouse BMCs with immature morphology.In the K562 xenograft model,KLC2-MT enhanced tumorigenic potential and diminished imatinib efficacy.Further studies reported that KLC2-MT augmented signal transducer and activator of transcription 3(STAT3)activation and nuclear accumulation in imatinib-treated CML cells.KLC2-WT and KLC2-MT interacted with mothers against decapentaplegic homolog 2(SMAD2);however,the latter impaired transforming growth factor-beta(TGF-β)–mediated SMAD2/3 activation while enhancing STAT3 phosphorylation.Conclusions:This study demonstrates the biological and functional importance of KLC2 mutation in CML cells,potentially enabling the development of better treatment strategies for CML patients carrying KLC2 mutations and providing enhanced understanding of the disease progression.展开更多
Lung cancer is one of the main causes of cancer-related deaths globally,with non-small cell lung cancer(NSCLC)being the most prevalent histological subtype of lung cancer.Glutathione peroxidase 4(GPX4)is a crucial ant...Lung cancer is one of the main causes of cancer-related deaths globally,with non-small cell lung cancer(NSCLC)being the most prevalent histological subtype of lung cancer.Glutathione peroxidase 4(GPX4)is a crucial antioxidant enzyme that plays a role in regulating ferroptosis.It is also involved in a wide variety of biological processes,such as tumor cell growth invasion,migration,and resistance to drugs.This study comprehensively examined the role of GPX4 in NSCLC and investigated the clinical feasibility of targeting GPX4 for NSCLC treatment.We discovered that GPX4 influences the progression of NSCLC by modulating multiple signaling pathways,and that blocking GPX4 can trigger ferroptosis and increase the sensitivity to chemotherapy.As a result,GPX4 represents a prospective therapeutic target for NSCLC.Targeting GPX4 inhibits the development of NSCLC cells and decreases their resistance to treatment.展开更多
Drug resistance remains a major challenge in breast cancer chemotherapy,yet the metabolic alterations underlying this phenomenon are not fully understood.There is much evidence indicating the cellular heterogeneity am...Drug resistance remains a major challenge in breast cancer chemotherapy,yet the metabolic alterations underlying this phenomenon are not fully understood.There is much evidence indicating the cellular heterogeneity among cancer cells,which exhibit varying degrees of metabolic reprogramming and thus may result in differential contributions to drug resistance.A home-built single-cell quantitative mass spectrometry(MS)platform,which integrates micromanipulation and electro-osmotic sampling,was developed to quantitatively profile the tricarboxylic acid(TCA)cycle metabolites at the single-cell level.Using this platform,the metabolic profiles of drug-sensitive MCF-7 breast cancer cells and their drug-resistant derivative MCF-7/ADR cells were compared.This results revealed a selective upregulation of downstream TCA cycle metabolites includingα-ketoglutarate,succinate,fumarate,and malate in drug-resistant cancer cells,while early TCA metabolites remained largely unchanged.Furthermore,notable variations in the abundance of the metabolites were observed in individual cells.The comparative analysis also revealed that not all MCF-7/ADR cells exhibit the same degree of metabolic deviation from the parental line in the metabolites during resistance acquisition.The observed metabolic profiles indicate enhanced glutaminolysis,altered mitochondrial electron transport chain activity,and increased metabolic flexibility in drug-resistant cancer cells that support their survival under chemotherapeutic stress.The findings further suggest the potential for incorporating cellular metabolic heterogeneity into future drug resistance studies.展开更多
Drug resistance continues to be the principal limiting factor in achieving a cure for patients with cancer,significantly hindering the long-term efficacy of novel cancer drugs.Accumulating evidence has shown that meta...Drug resistance continues to be the principal limiting factor in achieving a cure for patients with cancer,significantly hindering the long-term efficacy of novel cancer drugs.Accumulating evidence has shown that metabolites derived from tumor cells regulate immune cell metabolism via tumor microenvironment crosstalk.However,as immunometabolic research has deepened,the leading role played by the intrinsic metabolic regulation of immune cells in the drug resistance of tumor cells has been discovered.Immune metabolites have been shown to cause immune resistance,target therapy resistance,and chemotherapy resistance,and drugs that target immune metabolism have great potential.To date,researchers have not fully explored the impact of immune-derived metabolites on tumor cells and their influence on the responsiveness to cancer drugs.In this review,we focus on the lactate,fatty acid,glucose,and nucleotide metabolic alterations that take place in T cells and macrophages and how these changes can impair anti-tumor immunity,ultimately promoting tumor cell survival and decreasing responsiveness to the corresponding therapeutic approaches.We present the current developments in drugs targeting immunometabolic pathways and propose constructive suggestions,such as precise delivery to immune cell targets to enhance efficacy and safety,offering novel perspectives for cancer drug development.展开更多
INTRODUCTIONDevelopment of drug-resistance to chemotherapyand subsequent metastasis of tumor are primarilyresponsible for treatment failure and the death fromcancer. There have been many previous studies onthe relatio...INTRODUCTIONDevelopment of drug-resistance to chemotherapyand subsequent metastasis of tumor are primarilyresponsible for treatment failure and the death fromcancer. There have been many previous studies onthe relationship between expression of multidrugresistance (MDR) phenotype P-glycoprotein (P-gp)and the malignant properties of tumors, but theresults are often conflicting[1-8]. The difference intumor types or MDR phenotype induced by specificagents might account for this discrepancy. Taxotere(TXT), a member of the family of taxanes, hasantitumor activity through its effect of promotingthe polymerization of tubulin[9,10].展开更多
Objective This study aimed to investigate the prevalence of HIV pretreatment drug resistance(PDR)and the transmission clusters associated with PDR-related mutations in newly diagnosed,treatmentnaive patients between 2...Objective This study aimed to investigate the prevalence of HIV pretreatment drug resistance(PDR)and the transmission clusters associated with PDR-related mutations in newly diagnosed,treatmentnaive patients between 2020 and 2023 in Dehong prefecture,Yunnan province,China.Methods Demographic information and plasma samples were collected from study participants.PDR was assessed using the Stanford HIV Drug Resistance Database.The Tamura-Nei 93 model within HIVTRACE was employed to compute pairwise matches with a genetic distance of 0.015 substitutions per site.Results Among 948 treatment-naive individuals with eligible sequences,36 HIV subtypes were identified,with unique recombinant forms(URFs)being the most prevalent(18.8%,178/948).The overall prevalence of PDR was 12.4%(118/948),and resistance to non-nucleotide reverse transcriptase inhibitors(NNRTIs),nucleotide reverse transcriptase inhibitors(NRTIs),and protease inhibitors(PIs)was10.7%,1.3%,and 1.6%,respectively.A total of 91 clusters were identified,among which eight showed evidence of PDR strain transmission.The largest PDR-associated cluster consisted of six CRF01_AE drugresistant strains carrying K103N and V179T mutations;five of these individuals had initial CD4^(+)cell counts<200 cells/μL.Conclusion The distribution of HIV subtypes in Dehong is diverse and complex.PDR was moderately prevalent(12.4%)between 2020 and 2023.Evidence of transmission of CRF01_AE strains carrying K103N and V179T mutations was found.Routine surveillance of PDR and the strengthening of control measures are essential to limit the spread of drug-resistance HIV strains.展开更多
Drug resistance poses a significant challenge to effective long-term treatment across various medical fields.This study proposed a feasible strategy to enhance lysosomal alkalinization by transporting mitochondria-tar...Drug resistance poses a significant challenge to effective long-term treatment across various medical fields.This study proposed a feasible strategy to enhance lysosomal alkalinization by transporting mitochondria-targeting quaternary ammonium salts into lysosomes,creating a deprotonated environment.This environment allows drugs to bypass protonation issues in lysosomes,thereby reversing drug resistance and improving therapeutic efficacy.As a proof of concept,a quaternary ammonium salt-based pH indicator was developed,berberrubine(BRB),enhancing the action of the anticancer drug hydroxycamptothecin(HCPT)in resistant cells.BRB-induced alkalinization increased lysosomal pH and deactivated lysosomal activity,enabling HCPT to bypass protonation constraints.This enhancement markedly improved the anticancer efficacy of HCPT in resistant cells,providing an innovative approach to address drug resistance and advancing therapeutic technologies.展开更多
Objectives:Non-small cell lung cancer(NSCLC)represents a formidable malignancy characterized by its marked metastatic potential and intrinsic resistance to therapeutic interventions.The identification of potential bio...Objectives:Non-small cell lung cancer(NSCLC)represents a formidable malignancy characterized by its marked metastatic potential and intrinsic resistance to therapeutic interventions.The identification of potential biomarkers delineating the progression and metastatic cascade of NSCLC assumes paramount importance in fostering advancements toward enhanced patient outcomes and prognostic stratification.Methods:The expression level of the actin-related protein 2/3 complex;subunit 1A(ARPC1A)in NSCLC was evaluated using The Cancer Genome Atlas(TCGA)and Gene Expression Profiling Interactive Analysis(GEPIA)databases;along with the LinkedOmics database for co-expression genes.Further verification of ARPC1A expression in normal lung cells and NSCLC cells;as well as in normal tissues and lung cancer tissues;was performed using quantitative real-time reverse transcription PCR(RTqPCR)and Western blotting.The function of ARPC1A was explored through Gene Set Enrichment Analysis(GSEA)and immune infiltration analysis;followed by functional experiments for validation.Results:ARPC1A is upregulated in NSCLC and is associated with unfavorable clinical prognoses.Additionally,the Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analysis highlights a potential link between the ARPC1A gene and the cell cycle and p53 signaling pathways.ARPC1A also promotes cell proliferation and resistance to chemotherapeutic drugs,thereby enhancing the oncogenic potential of NSCLC.Relevant cell-based experiments confirm that targeted inhibition of ARPC1A effectively suppresses cellular migratory and invasive capabilities.The immune infiltration analysis showed a close association between ARPC1A expression and various immune components,suggesting ARPC1A may interact with the tumor microenvironment.Mechanistically,ARPC1A promotes cell migration by stimulating the epithelialto-mesenchymal transition(EMT).Conclusion:The study results revealed the potential of ARPC1A as a valuable prognostic biomarker for NSCLC.Additionally,the associated mechanisms provide insights that may pave the way for therapeutic interventions for NSCLC patients.展开更多
Lactylation,a post-translational modification process that adds lactate groups to lysine residues,plays a crucial role in cancer biology,especially in drug resistance.However,the specificmolecular mechanisms of lactyl...Lactylation,a post-translational modification process that adds lactate groups to lysine residues,plays a crucial role in cancer biology,especially in drug resistance.However,the specificmolecular mechanisms of lactylation in cancer progression and drug resistance are still unclear,and therapeutic strategies targeting the lactylation pathway are expected to overcome metabolic reprogramming and immune evasion.Therefore,this article provides a comprehensive description and summary of lactylationmodification and tumor drug resistance.Numerous studies have shown that,due to theWarburg effect,there is an abnormally high level of lactate in tumor cells.Elevated levels of lactate promote metabolic reprogramming and alter key cellular processes,including gene expression,DNA repair,and immune regulation.These cellular processes are precisely the key factors for tumor cells to develop drug resistance.Lactylation also affects the tumor microenvironment,promoting immune evasion and resistance to immunotherapy in tumor cells.Thismodification affects proteins involved in metabolic pathways,glycolysis,and mitochondrial function,further supporting tumor growth and metastasis.Therefore,this article provides a comprehensive description and summary of lactylation modification and tumor drug resistance to clarify the specific mechanisms between the two and provide references and directions for future research on tumor drug resistance.展开更多
BACKGROUND Helicobacter pylori(H.pylori),a globally prevalent pathogen,is exhibiting increasing rates of antimicrobial resistance.However,clinical implementation of pre-treatment susceptibility testing remains limited...BACKGROUND Helicobacter pylori(H.pylori),a globally prevalent pathogen,is exhibiting increasing rates of antimicrobial resistance.However,clinical implementation of pre-treatment susceptibility testing remains limited due to the organism’s fastidious growth requirements and prolonged culture time.AIM To propose a novel detection method utilizing antibiotic-supplemented media to inhibit susceptible strains,while resistant isolates were identified through urease-mediated hydrolysis of urea,inducing a phenol red color change for visual confirmation.METHODS Colombia agar was supplemented with urea,phenol red,and nickel chloride,and the final pH was adjusted to 7.35.Antibiotic-selective media were prepared by incorporating amoxicillin(0.5μg/mL),clarithromycin(2μg/mL),metronidazole(8μg/mL),or levofloxacin(2μg/mL)into separate batches.Gastric antral biopsies were homogenized and inoculated at 1.0×105 CFU onto the media,and then incubated under microaerobic conditions at 37°C for 28-36 hours.Resistance was determined based on a color change from yellow to pink,and the results were validated via broth microdilution according to Clinical and Laboratory Standards Institute guidelines.RESULTS After 28-36 hours of incubation,the drug-resistant H.pylori isolates induced a light red color change in the medium.Conversely,susceptible strains(H.pylori 26695 and G27)produced no visible color change.Compared with the conventional 11-day protocol,the novel method significantly reduced detection time.Among 201 clinical isolates,182 were successfully evaluated using the new method,resulting in a 90.5%detection rate.This was consistent with the 95.5%agreement rate observed when compared with microdilution-based susceptibility testing.The success rate of the novel approach was significantly higher than that of the comparative method(P<0.01).The accuracy of the new method was comparable to that of the dilution method.CONCLUSION The novel detection method can rapidly detect H.pylori drug resistance within 28-36 hours.With its operational simplicity and high diagnostic performance,it holds strong potential for clinical application in the management of H.pylori antimicrobial resistance.展开更多
OBJECTIVE: To probe insights into the reversal effect of bufalin on vincristine-acquired multidrug resistance(MDR) in human leukemia cell line K562/VCR.METHODS: Proliferative inhibition rate and the reversal index(RI)...OBJECTIVE: To probe insights into the reversal effect of bufalin on vincristine-acquired multidrug resistance(MDR) in human leukemia cell line K562/VCR.METHODS: Proliferative inhibition rate and the reversal index(RI) of bufalin were determined by Methyl thiazolyl tetrazolium assay. The uptake of Adriamycin(ADM) in K562/VCR cells, cell cycle and apoptosis rate were determined by flow cytometry(FCM). Cell morphologic changes were observed with Wright-Giemsa staining. The expression of P-glycoprotein(P-gp), multidrug-associated protein-1(MRP1), Bcl-x L and Bax protein were measured by immunocytochemistry.RESULTS: The human leukemia multidrug resistant K562/VCR cells showed no cross-resistance to bufalin. The RIs of bufalin at concentrations of 0.0002,0.001 and 0.005 μmol/L were 4.85, 6.94 and 14.77,respectively. Preincubation of 0.001 μmol/L bufalin for 2 h could increase intracellular ADM fluorescence intensity to 28.07%(P<0.05) and down-regulate MRP1 expression simultaneously, but no remarkable effect was found on P-gp protein. Cell cycle analysis indicated increased apoptosis rate and apparent decreased G2/M phase proportion after treatment with bufalin. When exposed to 0.01μmol/L bufalin, typical morphological changes of apoptosis could be observed. Down-regulation of Bcl-x L and up-regulation of Bax expression in K562/VCR cells could be detected by immunocytochemistry.CONCLUSION: Bufalin could partly reverse the MDR of K562/VCR cells, with a possible mechanism of down-regulating MRP1 expression and activating apoptosis pathway by altering Bcl-x L/Bax ratio.展开更多
Anticancer drug resistance remains a major challenge in cancer treatment hindering the efficacy of chemotherapy and targeted therapies.Conventional two-dimensional(2D)cell cultures cannot replicate the complexity of t...Anticancer drug resistance remains a major challenge in cancer treatment hindering the efficacy of chemotherapy and targeted therapies.Conventional two-dimensional(2D)cell cultures cannot replicate the complexity of the in vivo tumor microenvironment(TME),limiting their utility for drug resistance research.Therefore,three-dimensional(3D)tumor models have proven to be a promising alternative for investigating chemoresistance mechanisms.In this review,various cancer 3D models,including spheroids,organoids,scaffold-based models,and bioprinted models,are comprehensively evaluated with a focus on their application in drug resistance studies.We discuss the materials,properties,and advantages of each model,highlighting their ability to better mimic the TME and represent complex mechanisms of drug resistance such as epithelial-mesenchymal transition(EMT),drug efflux,and tumor-stroma interactions.Furthermore,we investigate the limitations of these models,including scalability,reproducibility and technical challenges,as well as their potential therapeutic impact on personalized medicine.Through a thorough comparison of model performance,we provide insights into the strengths and weaknesses of each approach and offer guidance for model selection based on specific research needs.展开更多
Overview of the DNA damage response(DDR)in tumor cells.DDR is a highly coordinated signaling network that repairs DNA damage caused by intrinsic cellular processes and extrinsic insults,thereby preventing genome insta...Overview of the DNA damage response(DDR)in tumor cells.DDR is a highly coordinated signaling network that repairs DNA damage caused by intrinsic cellular processes and extrinsic insults,thereby preventing genome instability.Depending on the type of damage,distinct DNA damage repair and DNA damage tolerance(DDT)pathways are involved and coordinately regulated.展开更多
BACKGROUND: Multidrug resistance is a major obstacle in cancer chemotherapy. We examined whether the antisense RNA of multidrug resistance gene 1 (mdr1) could reverse multidrug resistance in the human hepatocellular c...BACKGROUND: Multidrug resistance is a major obstacle in cancer chemotherapy. We examined whether the antisense RNA of multidrug resistance gene 1 (mdr1) could reverse multidrug resistance in the human hepatocellular carcinoma (HCC) cell line SMMC7721/ADM. METHODS: The recombinant adenoviruses pAdEasy- GFP-ASmdr1 product was produced by the adenoviral vector AdEasy system, which can express antisense RNA against the mdr1 gene. Following that, the recombinant adenovirus was transfected into the P-glycoprotein- producing multidrug resistance cell line, SMMC7721/ADM human HCC cells resistant to adriamycin (ADM) and daunorubicin (DNR). In order to investigate the reversal of multidrug resistance phenotype, we measured the expression of mdr1 mRNA by RT-PCR and the production of P-glycoprotein by flow cytometry. The sensitivities for ADM and DNR SMMC7721/ADM cells were examined by [3-(4, 5-dimethylthi-azol-2-yl)-2,5 diphenyl-terazolium bromide] (MTT) analysis. RESULTS: The low-level expression of mdr1 mRNA and P-glycoprotein production were observed in parental sensitive cells SMMC/7721 in addition to the overexpressionof mdr1 mRNA and P-glycoprotein in SMMC7721/ADM cells. The transfection of antisense-RNA into SMMC7721/ ADM cells resulted in decreases of mdr1 mRNA and P-glycoprotein, but increase of drug sensitivities. The sensitivities of transfected SMMC7721/ADM cells to ADM and DNR in IC50 reduced by 31.25% and 62.96% respectively. CONCLUSIONS: Mdr1 antisense RNA can increase the sensitivities of SMMC7721/ADM cells to anticancer drug by decreasing the expression of the mdr1 gene and inhibiting P-glycoprotein expression. This strategy may be applicable to cancer patients with P-glycoportein mediated multidrug resistance.展开更多
Drug resistance poses an escalating global challenge in the battle against infections.The effectiveness of conventional antibiotics and other anti-infective drugs is waning as microbes develop heightened resistance to...Drug resistance poses an escalating global challenge in the battle against infections.The effectiveness of conventional antibiotics and other anti-infective drugs is waning as microbes develop heightened resistance to existing treatments.Antimicrobial resistance poses a formidable challenge to global health and development,ranking among the top 10 public health threats to humanity as declared by the World Health Organization.Projections indicate that if left unaddressed,antimicrobial resistance could inflict an annual economic burden on the global GDP ranging from$1trillion to$3.4 trillion by 2030.Consequently,the management of common infections becomes increasingly arduous,while the likelihood of disease transmission,severe illness,and mortality escalates.展开更多
文摘Summary: The expression and functional activity of multiple drug resistance (MDR1) gene in human normal bone marrow CD34+ cells was observed. Human normal bone marrow CD34+ cells were enriched with magnetic cell sorting (MACS) system, and then liposome-mediated MDR1 gene was transferred into bone marrow CD34+ cells. Fluorescence-activated cell sorter was used to evaluate the expression and functional activity of P-glycoprotein (P-gp) encoded by MDR1 gene. It was found that the purity of bone marrow CD34+ cells was approximately (91±4.56) % and recovery rate was (72.3±2.36) % by MACS. The expression of P-gp in the transfected CD34+cells was obviously higher than that in non-transfected CD34+ cells. The amount of P-gp in non-transfected CD34+ cells was (11.2±2.2) %, but increased to (23.6±2.34) % 48 h after gene transfection (P<0.0l). The amount of P-gp was gradually decreased to the basic level one week later. The accumulation and extrusion assays showed that the overexpression of P-gp could efflux Rh-123 out of cells and there was low fluorescence within the transfected cells. The functional activity of P-gp could be inhibited by 10 μg/ml verapamil. It was suggested that the transient and highly effective expression and functional activity of P-gp could be obtained by liposome-mediated MRD1 transferring into human normal bone marrow CD34+ cells.
基金National Natural Science Foundation of Chinese,No.3988007
文摘AIM To observe the drug sensitizing effect andrelated mechanisms of fas gene transduction onhuman drug-resistant gastric cancer cellSGC7901/VCR(resistant to Vincristine).METHODS The cell cycle alteration wasobserved by FACS.The sensitivity of gastriccancer cells to apoptosis was determined by invitro apoptosis assay.The drug sensitization ofcells to several anti-tumor drugs was observedby MTT assay.Immunochemical method wasused to show expression of P-gp and Topo Ⅱ ingastric cancer cells.RESULTS Comparing to SGC7901 and pBK-SGC7901/VCR,fas-SGC7901/VCR showeddecreasing G2 cells and increasing S cells,theG2 phase fraction of pBK-SGC7901/VCR wasabout 3.0 times that of fas-SGC7901/VCR,but Sphase fraction of fas-SGC7901/VCR was about1.9 times that of pBK-SGC7901/VCR,indicatingS phase arrest of fas-SGC7901/VCR.FACS alsosuggested apoptosis of fas-SGC7901/VCR,fas-SGC7901/VCR was more sensitive to apoptosisinducing agent VM-26 than pBK-SGC7901/VCR.MTT assay showed increased sensitization offas-SGC7901/VCR to DDP,MMC and 5-FU,butsame sensitization to VCR according to pBK-SGC7901/VCR.SGC7901,pBK-SGC7901/ VCRand fas-SGC7901/VCR had positively stainedTopo Ⅱ equally.P-gp staining in pBK- SGC7901/VCR was stronger than in SG07901,but there was little staining of P-gp in fas.SGC7901/VCR.CONCLUSION fas gene transduction couldreverse the MDR of human drug-resistant gastriccancer cell SGC7901/VCR to a degree,possiblybecause of higher sensitization to apoptosis anddecreased expression of P-gp.
文摘Multiple myeloma(MM) is a cancer caused by uncontrolled proliferation of antibody-secreting plasma cells in bone marrow, which represents the second most common hematological malignancy. MM is a highly heterogeneous disease and can be classified into a spectrum of subgroups based on their molecular and cytogenetic abnormalities. In the past decade, novel therapies, especially, the first-in-class proteasome inhibitor bortezomib, have been revolutionary for the treatment of MM patients. Despite these remarkable achievements, myeloma remains incurable with a high frequency of patients suffering from a relapse, due to drug resistance. Mutation in the proteasome β5-subunit(PSMB5) was found in a bortezomib-resistant cell line generated via long-term coculture with increasing concentrations of bortezomib in 2008, but their actual implication in drug resistance in the clinic has not been reported until recently. A recent study discovered four resistance-inducing PSMB5 mutations from a relapsed MM patient receiving prolonged bortezomib treatment. Analysis of the dynamic clonal evolution revealed that two subclones existed at the onset of disease, while the other two subclones were induced. Protein structural modeling and functional assays demonstrated that all four mutations impaired the binding of bortezomib to the 20 S proteasome, conferring different degrees of resistance. The authors further demonstrated two potential approaches to overcome drug resistance by using combination therapy for targeting proteolysis machinery independent of the 20 S proteasome.
基金the National Natural Science Foundation of China,No.8180306the Natural Science Foundation of Zhejiang Province,No.LY18C070002the 521 Talent Project of Zhejiang Sci-Tech University,No.2021437620 and No.2019337459.
文摘The transforming growth factor(TGF)-βsignaling pathway controls many cellular processes,including proliferation,differentiation,and apoptosis.Abnormalities in the TGF-βsignaling pathway and its components are closely related to the occurrence of many human diseases,including cancer.Mothers against decapentaplegic homolog 4(Smad4),also known as deleted in pancreatic cancer locus 4,is a typical tumor suppressor candidate gene locating at q21.1 of human chromosome 18 and the common mediator of the TGF-β/Smad and bone morphogenetic protein/Smad signaling pathways.It is believed that Smad4 inactivation correlates with the development of tumors and stem cell fate decisions.Smad4 also interacts with cytokines,miRNAs,and other signaling pathways,jointly regulating cell behavior.However,the regulatory function of Smad4 in tumorigenesis,stem cells,and drug resistance is currently controversial.In addition,Smad4 represents an attractive therapeutic target for cancer.Elucidating the specific role of Smad4 is important for understanding the mechanism of tumorigenesis and cancer treatment.Here,we review the identification and characterization of Smad4,the canonical TGF-β/Smad pathway,as well as the multiple roles of Smad4 in tumorigenesis,stem cells,and drug resistance.Furthermore,we provide novel insights into the prospects of Smad4-targeted cancer therapy and the challenges that it will face in the future.
文摘Drug resistance is becoming a great problem in developing countries due to excessive use and misuse of antibiotics. The emergence of new pathogenic strains with resistance developed against most of the antibiotics which may cause,difficult to treat infection.To understand the current scenario in different mode of infection is most important for the clinicians and medical practitioners.This article summarized some common infections and antibiotic resistance pattern found among these pathogens.
基金supported by grants from the Ministry of Science and Technology,Taiwan(MOST108-2314-B-182-006,MOST109-2314-B-182-071:Lee-Yung Shih)the Ministry of Health and Welfare,Taiwan(MOHW110-TDU-B-212-134011:Lee-Yung Shih)+3 种基金Chang Gung Memorial Hospital(CMRPG3D1524,OMRPG3E0031:Lee-Yung Shih)the Grant-in-Aid for the Japan Society for the Promotion of Science(JSPS)KAKENHI(JP19H05656:Seishi Ogawa,22K16320:Yotaro Ochi)the Japan Agency for Medical Research and Development(AMED)(JP19cm0106501h0004,JP19ck0106250h0003:Seishi Ogawa)the Ministry of Education,Culture,Sports,Science and Technology of Japan(MEXT)(hp200138,hp210167:Seishi Ogawa)。
文摘Background:Breakpoint Cluster Region-Abelson(BCR::ABL1)fusion protein is essential in the pathogenesis of chronic myeloid leukemia(CML);however,the chronic-to-blast phase transformation remains elusive.We identified novel kinesin light chain 2(KLC2)mutations in CML-myeloid blast phase patients.We aimed to examine the functional role of KLC2 mutations in leukemogenesis.Methods:To evaluate the biological role of KLC2 mutants(MT)in CML cells,we expressed KLC2-MT in different human CML cell lines harboring BCR::ABL1 and performed immunoblot,immunofluorescence,cell proliferation,differentiation,and apoptosis;Tyrosine kinase inhibitor(TKI)-drug activities;and clonogenic assays for in vitro functional analyses.We co-expressed KLC2-MT and BCR::ABL1 in mouse bone marrow cells(BMCs)to evaluate their clonogenic and self-renewal abilities ex vivo.Furthermore,we examined tumorigenic activity and drug efficacy in the K562 xenograft model.Results:KLC2-MT overexpression in BCR::ABL1-positive K562 and KU812 CML cells promoted cell proliferation and clonogenic potential,decreased imatinib sensitivity,and reduced apoptosis.Serial colony replating assays revealed that KLC2-MT and BCR::ABL1 co-expression enhanced the self-renewal ability of mouse BMCs with immature morphology.In the K562 xenograft model,KLC2-MT enhanced tumorigenic potential and diminished imatinib efficacy.Further studies reported that KLC2-MT augmented signal transducer and activator of transcription 3(STAT3)activation and nuclear accumulation in imatinib-treated CML cells.KLC2-WT and KLC2-MT interacted with mothers against decapentaplegic homolog 2(SMAD2);however,the latter impaired transforming growth factor-beta(TGF-β)–mediated SMAD2/3 activation while enhancing STAT3 phosphorylation.Conclusions:This study demonstrates the biological and functional importance of KLC2 mutation in CML cells,potentially enabling the development of better treatment strategies for CML patients carrying KLC2 mutations and providing enhanced understanding of the disease progression.
文摘Lung cancer is one of the main causes of cancer-related deaths globally,with non-small cell lung cancer(NSCLC)being the most prevalent histological subtype of lung cancer.Glutathione peroxidase 4(GPX4)is a crucial antioxidant enzyme that plays a role in regulating ferroptosis.It is also involved in a wide variety of biological processes,such as tumor cell growth invasion,migration,and resistance to drugs.This study comprehensively examined the role of GPX4 in NSCLC and investigated the clinical feasibility of targeting GPX4 for NSCLC treatment.We discovered that GPX4 influences the progression of NSCLC by modulating multiple signaling pathways,and that blocking GPX4 can trigger ferroptosis and increase the sensitivity to chemotherapy.As a result,GPX4 represents a prospective therapeutic target for NSCLC.Targeting GPX4 inhibits the development of NSCLC cells and decreases their resistance to treatment.
基金supported by National Natural Science Foundation of China(22374080,22174068,21722504)Primary Research&Development Plan of Jiangsu Province(BK20221303,BE2022796)+1 种基金Open Foundation of State Key Laboratory of Reproductive Medicine(SKLRM-2022BP1,JX116GSP20240507)Science and Technology Development Fund of NJMU(NJMUQY2022003)。
文摘Drug resistance remains a major challenge in breast cancer chemotherapy,yet the metabolic alterations underlying this phenomenon are not fully understood.There is much evidence indicating the cellular heterogeneity among cancer cells,which exhibit varying degrees of metabolic reprogramming and thus may result in differential contributions to drug resistance.A home-built single-cell quantitative mass spectrometry(MS)platform,which integrates micromanipulation and electro-osmotic sampling,was developed to quantitatively profile the tricarboxylic acid(TCA)cycle metabolites at the single-cell level.Using this platform,the metabolic profiles of drug-sensitive MCF-7 breast cancer cells and their drug-resistant derivative MCF-7/ADR cells were compared.This results revealed a selective upregulation of downstream TCA cycle metabolites includingα-ketoglutarate,succinate,fumarate,and malate in drug-resistant cancer cells,while early TCA metabolites remained largely unchanged.Furthermore,notable variations in the abundance of the metabolites were observed in individual cells.The comparative analysis also revealed that not all MCF-7/ADR cells exhibit the same degree of metabolic deviation from the parental line in the metabolites during resistance acquisition.The observed metabolic profiles indicate enhanced glutaminolysis,altered mitochondrial electron transport chain activity,and increased metabolic flexibility in drug-resistant cancer cells that support their survival under chemotherapeutic stress.The findings further suggest the potential for incorporating cellular metabolic heterogeneity into future drug resistance studies.
基金supported by the National Key Research and Development Program of China(No.2023YFC2508500)National Natural Science Foundation of China(No.82272951)National Natural Science Foundation of China(No.82272953)。
文摘Drug resistance continues to be the principal limiting factor in achieving a cure for patients with cancer,significantly hindering the long-term efficacy of novel cancer drugs.Accumulating evidence has shown that metabolites derived from tumor cells regulate immune cell metabolism via tumor microenvironment crosstalk.However,as immunometabolic research has deepened,the leading role played by the intrinsic metabolic regulation of immune cells in the drug resistance of tumor cells has been discovered.Immune metabolites have been shown to cause immune resistance,target therapy resistance,and chemotherapy resistance,and drugs that target immune metabolism have great potential.To date,researchers have not fully explored the impact of immune-derived metabolites on tumor cells and their influence on the responsiveness to cancer drugs.In this review,we focus on the lactate,fatty acid,glucose,and nucleotide metabolic alterations that take place in T cells and macrophages and how these changes can impair anti-tumor immunity,ultimately promoting tumor cell survival and decreasing responsiveness to the corresponding therapeutic approaches.We present the current developments in drugs targeting immunometabolic pathways and propose constructive suggestions,such as precise delivery to immune cell targets to enhance efficacy and safety,offering novel perspectives for cancer drug development.
基金Supported in part by phone-Poulenc Rorer Pharmaceuticals INC
文摘INTRODUCTIONDevelopment of drug-resistance to chemotherapyand subsequent metastasis of tumor are primarilyresponsible for treatment failure and the death fromcancer. There have been many previous studies onthe relationship between expression of multidrugresistance (MDR) phenotype P-glycoprotein (P-gp)and the malignant properties of tumors, but theresults are often conflicting[1-8]. The difference intumor types or MDR phenotype induced by specificagents might account for this discrepancy. Taxotere(TXT), a member of the family of taxanes, hasantitumor activity through its effect of promotingthe polymerization of tubulin[9,10].
基金supported by the National Key Research and Development Program of China(2022YFC2305201)National Natural Science Foundation of China(71874168)。
文摘Objective This study aimed to investigate the prevalence of HIV pretreatment drug resistance(PDR)and the transmission clusters associated with PDR-related mutations in newly diagnosed,treatmentnaive patients between 2020 and 2023 in Dehong prefecture,Yunnan province,China.Methods Demographic information and plasma samples were collected from study participants.PDR was assessed using the Stanford HIV Drug Resistance Database.The Tamura-Nei 93 model within HIVTRACE was employed to compute pairwise matches with a genetic distance of 0.015 substitutions per site.Results Among 948 treatment-naive individuals with eligible sequences,36 HIV subtypes were identified,with unique recombinant forms(URFs)being the most prevalent(18.8%,178/948).The overall prevalence of PDR was 12.4%(118/948),and resistance to non-nucleotide reverse transcriptase inhibitors(NNRTIs),nucleotide reverse transcriptase inhibitors(NRTIs),and protease inhibitors(PIs)was10.7%,1.3%,and 1.6%,respectively.A total of 91 clusters were identified,among which eight showed evidence of PDR strain transmission.The largest PDR-associated cluster consisted of six CRF01_AE drugresistant strains carrying K103N and V179T mutations;five of these individuals had initial CD4^(+)cell counts<200 cells/μL.Conclusion The distribution of HIV subtypes in Dehong is diverse and complex.PDR was moderately prevalent(12.4%)between 2020 and 2023.Evidence of transmission of CRF01_AE strains carrying K103N and V179T mutations was found.Routine surveillance of PDR and the strengthening of control measures are essential to limit the spread of drug-resistance HIV strains.
基金supported by Young Elite Scientists Sponsorship Program by China Association for Science and Technology(No.CACM-2023-QNRC1–02)Shandong Province Key R&D Program(Major Technological Innovation Project)(No.2021CXGC010501)+6 种基金National Natural Science Foundation of China(No.22107059)Natural Science Foundation of Shandong Province(No.ZR2021QH057)Program for Youth Innovation Technology in Colleges and Universities of Shandong Province of China(No.2021KJ035)Taishan Scholars Program(No.TSQN202211221)Shandong Science Fund for Excellent Young Scholars(No.ZR2022YQ66)Funded by Shandong Postdoctoral Science Foundation(No.SDCX-ZG-202400084)the National Administration of Traditional Chinese Medicine Young Qihuang Scholar Project。
文摘Drug resistance poses a significant challenge to effective long-term treatment across various medical fields.This study proposed a feasible strategy to enhance lysosomal alkalinization by transporting mitochondria-targeting quaternary ammonium salts into lysosomes,creating a deprotonated environment.This environment allows drugs to bypass protonation issues in lysosomes,thereby reversing drug resistance and improving therapeutic efficacy.As a proof of concept,a quaternary ammonium salt-based pH indicator was developed,berberrubine(BRB),enhancing the action of the anticancer drug hydroxycamptothecin(HCPT)in resistant cells.BRB-induced alkalinization increased lysosomal pH and deactivated lysosomal activity,enabling HCPT to bypass protonation constraints.This enhancement markedly improved the anticancer efficacy of HCPT in resistant cells,providing an innovative approach to address drug resistance and advancing therapeutic technologies.
基金supported by the Natural Science Foundation of Anhui Province(ML 2308085MC80)the Anhui Medical University Research and Innovation Talent Team(KZ).
文摘Objectives:Non-small cell lung cancer(NSCLC)represents a formidable malignancy characterized by its marked metastatic potential and intrinsic resistance to therapeutic interventions.The identification of potential biomarkers delineating the progression and metastatic cascade of NSCLC assumes paramount importance in fostering advancements toward enhanced patient outcomes and prognostic stratification.Methods:The expression level of the actin-related protein 2/3 complex;subunit 1A(ARPC1A)in NSCLC was evaluated using The Cancer Genome Atlas(TCGA)and Gene Expression Profiling Interactive Analysis(GEPIA)databases;along with the LinkedOmics database for co-expression genes.Further verification of ARPC1A expression in normal lung cells and NSCLC cells;as well as in normal tissues and lung cancer tissues;was performed using quantitative real-time reverse transcription PCR(RTqPCR)and Western blotting.The function of ARPC1A was explored through Gene Set Enrichment Analysis(GSEA)and immune infiltration analysis;followed by functional experiments for validation.Results:ARPC1A is upregulated in NSCLC and is associated with unfavorable clinical prognoses.Additionally,the Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analysis highlights a potential link between the ARPC1A gene and the cell cycle and p53 signaling pathways.ARPC1A also promotes cell proliferation and resistance to chemotherapeutic drugs,thereby enhancing the oncogenic potential of NSCLC.Relevant cell-based experiments confirm that targeted inhibition of ARPC1A effectively suppresses cellular migratory and invasive capabilities.The immune infiltration analysis showed a close association between ARPC1A expression and various immune components,suggesting ARPC1A may interact with the tumor microenvironment.Mechanistically,ARPC1A promotes cell migration by stimulating the epithelialto-mesenchymal transition(EMT).Conclusion:The study results revealed the potential of ARPC1A as a valuable prognostic biomarker for NSCLC.Additionally,the associated mechanisms provide insights that may pave the way for therapeutic interventions for NSCLC patients.
基金supported by the Anhui Provincial Health Commission Provincial Financial Support for Youth Programs(No.AHWJ2023A30159)Wuhu Science and Technology Program Project(No.2024kj072).
文摘Lactylation,a post-translational modification process that adds lactate groups to lysine residues,plays a crucial role in cancer biology,especially in drug resistance.However,the specificmolecular mechanisms of lactylation in cancer progression and drug resistance are still unclear,and therapeutic strategies targeting the lactylation pathway are expected to overcome metabolic reprogramming and immune evasion.Therefore,this article provides a comprehensive description and summary of lactylationmodification and tumor drug resistance.Numerous studies have shown that,due to theWarburg effect,there is an abnormally high level of lactate in tumor cells.Elevated levels of lactate promote metabolic reprogramming and alter key cellular processes,including gene expression,DNA repair,and immune regulation.These cellular processes are precisely the key factors for tumor cells to develop drug resistance.Lactylation also affects the tumor microenvironment,promoting immune evasion and resistance to immunotherapy in tumor cells.Thismodification affects proteins involved in metabolic pathways,glycolysis,and mitochondrial function,further supporting tumor growth and metastasis.Therefore,this article provides a comprehensive description and summary of lactylation modification and tumor drug resistance to clarify the specific mechanisms between the two and provide references and directions for future research on tumor drug resistance.
基金Supported by the Guangxi Science and Technology Major Projects,No.AA23073012the National Natural Science Foundation of China,No.32360035 and No.32060018。
文摘BACKGROUND Helicobacter pylori(H.pylori),a globally prevalent pathogen,is exhibiting increasing rates of antimicrobial resistance.However,clinical implementation of pre-treatment susceptibility testing remains limited due to the organism’s fastidious growth requirements and prolonged culture time.AIM To propose a novel detection method utilizing antibiotic-supplemented media to inhibit susceptible strains,while resistant isolates were identified through urease-mediated hydrolysis of urea,inducing a phenol red color change for visual confirmation.METHODS Colombia agar was supplemented with urea,phenol red,and nickel chloride,and the final pH was adjusted to 7.35.Antibiotic-selective media were prepared by incorporating amoxicillin(0.5μg/mL),clarithromycin(2μg/mL),metronidazole(8μg/mL),or levofloxacin(2μg/mL)into separate batches.Gastric antral biopsies were homogenized and inoculated at 1.0×105 CFU onto the media,and then incubated under microaerobic conditions at 37°C for 28-36 hours.Resistance was determined based on a color change from yellow to pink,and the results were validated via broth microdilution according to Clinical and Laboratory Standards Institute guidelines.RESULTS After 28-36 hours of incubation,the drug-resistant H.pylori isolates induced a light red color change in the medium.Conversely,susceptible strains(H.pylori 26695 and G27)produced no visible color change.Compared with the conventional 11-day protocol,the novel method significantly reduced detection time.Among 201 clinical isolates,182 were successfully evaluated using the new method,resulting in a 90.5%detection rate.This was consistent with the 95.5%agreement rate observed when compared with microdilution-based susceptibility testing.The success rate of the novel approach was significantly higher than that of the comparative method(P<0.01).The accuracy of the new method was comparable to that of the dilution method.CONCLUSION The novel detection method can rapidly detect H.pylori drug resistance within 28-36 hours.With its operational simplicity and high diagnostic performance,it holds strong potential for clinical application in the management of H.pylori antimicrobial resistance.
基金Shanghai Municipal Health Bureau:Traditional Chinese Medicine in Treating with Advanced Hepatocellular Carcinoma(No.ZYSNXD-CC-ZDYJ032)
文摘OBJECTIVE: To probe insights into the reversal effect of bufalin on vincristine-acquired multidrug resistance(MDR) in human leukemia cell line K562/VCR.METHODS: Proliferative inhibition rate and the reversal index(RI) of bufalin were determined by Methyl thiazolyl tetrazolium assay. The uptake of Adriamycin(ADM) in K562/VCR cells, cell cycle and apoptosis rate were determined by flow cytometry(FCM). Cell morphologic changes were observed with Wright-Giemsa staining. The expression of P-glycoprotein(P-gp), multidrug-associated protein-1(MRP1), Bcl-x L and Bax protein were measured by immunocytochemistry.RESULTS: The human leukemia multidrug resistant K562/VCR cells showed no cross-resistance to bufalin. The RIs of bufalin at concentrations of 0.0002,0.001 and 0.005 μmol/L were 4.85, 6.94 and 14.77,respectively. Preincubation of 0.001 μmol/L bufalin for 2 h could increase intracellular ADM fluorescence intensity to 28.07%(P<0.05) and down-regulate MRP1 expression simultaneously, but no remarkable effect was found on P-gp protein. Cell cycle analysis indicated increased apoptosis rate and apparent decreased G2/M phase proportion after treatment with bufalin. When exposed to 0.01μmol/L bufalin, typical morphological changes of apoptosis could be observed. Down-regulation of Bcl-x L and up-regulation of Bax expression in K562/VCR cells could be detected by immunocytochemistry.CONCLUSION: Bufalin could partly reverse the MDR of K562/VCR cells, with a possible mechanism of down-regulating MRP1 expression and activating apoptosis pathway by altering Bcl-x L/Bax ratio.
基金funded by the Ministry of Science,Technological Development and Innovation of the Republic of Serbia(grant numbers 451-03-136/2025-03/200007 and 451-03-136/2025-03/200042).
文摘Anticancer drug resistance remains a major challenge in cancer treatment hindering the efficacy of chemotherapy and targeted therapies.Conventional two-dimensional(2D)cell cultures cannot replicate the complexity of the in vivo tumor microenvironment(TME),limiting their utility for drug resistance research.Therefore,three-dimensional(3D)tumor models have proven to be a promising alternative for investigating chemoresistance mechanisms.In this review,various cancer 3D models,including spheroids,organoids,scaffold-based models,and bioprinted models,are comprehensively evaluated with a focus on their application in drug resistance studies.We discuss the materials,properties,and advantages of each model,highlighting their ability to better mimic the TME and represent complex mechanisms of drug resistance such as epithelial-mesenchymal transition(EMT),drug efflux,and tumor-stroma interactions.Furthermore,we investigate the limitations of these models,including scalability,reproducibility and technical challenges,as well as their potential therapeutic impact on personalized medicine.Through a thorough comparison of model performance,we provide insights into the strengths and weaknesses of each approach and offer guidance for model selection based on specific research needs.
基金the National Natural Science Foundation of China(Grant No.82330090 and Grant No.82341006 to C.G.)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA0460403 to C.G.)the Natural Science Foundation of Shanxi Province(Grant No.202203021211155 to X.M.).
文摘Overview of the DNA damage response(DDR)in tumor cells.DDR is a highly coordinated signaling network that repairs DNA damage caused by intrinsic cellular processes and extrinsic insults,thereby preventing genome instability.Depending on the type of damage,distinct DNA damage repair and DNA damage tolerance(DDT)pathways are involved and coordinately regulated.
基金This study was supported by the grant from National Natural Science Foundation of China (No: 30170925).
文摘BACKGROUND: Multidrug resistance is a major obstacle in cancer chemotherapy. We examined whether the antisense RNA of multidrug resistance gene 1 (mdr1) could reverse multidrug resistance in the human hepatocellular carcinoma (HCC) cell line SMMC7721/ADM. METHODS: The recombinant adenoviruses pAdEasy- GFP-ASmdr1 product was produced by the adenoviral vector AdEasy system, which can express antisense RNA against the mdr1 gene. Following that, the recombinant adenovirus was transfected into the P-glycoprotein- producing multidrug resistance cell line, SMMC7721/ADM human HCC cells resistant to adriamycin (ADM) and daunorubicin (DNR). In order to investigate the reversal of multidrug resistance phenotype, we measured the expression of mdr1 mRNA by RT-PCR and the production of P-glycoprotein by flow cytometry. The sensitivities for ADM and DNR SMMC7721/ADM cells were examined by [3-(4, 5-dimethylthi-azol-2-yl)-2,5 diphenyl-terazolium bromide] (MTT) analysis. RESULTS: The low-level expression of mdr1 mRNA and P-glycoprotein production were observed in parental sensitive cells SMMC/7721 in addition to the overexpressionof mdr1 mRNA and P-glycoprotein in SMMC7721/ADM cells. The transfection of antisense-RNA into SMMC7721/ ADM cells resulted in decreases of mdr1 mRNA and P-glycoprotein, but increase of drug sensitivities. The sensitivities of transfected SMMC7721/ADM cells to ADM and DNR in IC50 reduced by 31.25% and 62.96% respectively. CONCLUSIONS: Mdr1 antisense RNA can increase the sensitivities of SMMC7721/ADM cells to anticancer drug by decreasing the expression of the mdr1 gene and inhibiting P-glycoprotein expression. This strategy may be applicable to cancer patients with P-glycoportein mediated multidrug resistance.
文摘Drug resistance poses an escalating global challenge in the battle against infections.The effectiveness of conventional antibiotics and other anti-infective drugs is waning as microbes develop heightened resistance to existing treatments.Antimicrobial resistance poses a formidable challenge to global health and development,ranking among the top 10 public health threats to humanity as declared by the World Health Organization.Projections indicate that if left unaddressed,antimicrobial resistance could inflict an annual economic burden on the global GDP ranging from$1trillion to$3.4 trillion by 2030.Consequently,the management of common infections becomes increasingly arduous,while the likelihood of disease transmission,severe illness,and mortality escalates.
