Objective:Autophagy is a programmed cell death procedure,which has essential functions in tumorigenesis.However,its temporal expression and function under different status are yet to be determined.This study aims to i...Objective:Autophagy is a programmed cell death procedure,which has essential functions in tumorigenesis.However,its temporal expression and function under different status are yet to be determined.This study aims to investigate the temporal expression of autophagy and its possible function in 7,12-dimethylbenz[a]anthracene(DMBA)-induced hamster buccal-pouch cancer model(HBPCM).Methods:A total of 50 hamster buccal-pouch tumorigenesis models were established by painting DMBA for 4,8,10 and 13 weeks.The expression and subcellular localization of LC3,Beclin 1 and Bcl-2 in buccal lesions were evaluated by immunohistochemical staining and Western blotting.DNA damage was observed by immunohistochemical staining of 8-oHdG.The relationship between Beclin 1 and Bcl-2 was analyzed by immunofluorescence colocalization.Results:The expression levels of LC3 and Beclin 1 associated with autophagy in the experimental buccal pouch of HBPCM were significantly upregulated after 4 weeks(P<0.05),but gradually downregulated after 13 weeks of HBPCM induction.By contrast,the expression level of Bcl-2 was significantly upregulated after 13 weeks.The co-localized regions of Bcl-2 and Beclin 1 peaked after 4 weeks and then decreased gradually.The DNA damage in epithelial cells increased slightly after 4 weeks,and then rapidly decreased over the next 2 months.Conclusion:Autophagy is motivated by a tumor suppressor that diminishes carcinogen-induced DNA damage.However,autophagy is gradually suppressed,which may be attributed to the interaction between Bcl-2 and Beclin 1.This result indicates that the promotion of autophagy may suppress malignant transformation and provide new insights on future potential treatments of HBPCM.展开更多
To evaluate the apoptosis positivity, the expression of Bcl-2, bax proteinsin 30 patients with squamous cell cervix carcinoma before and after radiotherapy. Methods: By usingimmuno-histochemical and TDT-dUTP nick end ...To evaluate the apoptosis positivity, the expression of Bcl-2, bax proteinsin 30 patients with squamous cell cervix carcinoma before and after radiotherapy. Methods: By usingimmuno-histochemical and TDT-dUTP nick end labelling techniques, 30 cases of squamous cell cervicalcarcinoma were analyzed. Results: The apoptosis positivity before and after irradiation was 76.7%and 100% respectively, with the difference being significant (P 【 0.05); The positive rates of Bcl-2protein before and after irradiation were 73.3% and 46.7% respectively, with the difference beingsignificant (P 【 0.05); The positive rates of bax protein before and after irradiation were 86% and100% respectively, with the difference being significant (P 【 0.05). Conclusion: bax and Bcl-2protein play an important role in apoptosis induced by fractionated radiation therapy. Apoptosisinduced by irradiation is contributed to upregulation of bax protein or downregulation of Bcl-2protein.展开更多
AIM： To explore the relationship between clinicobiological behavior and the expression levels of telomerase activity, apoptosis, p53 gene and bcl-2 gene in gastrointestinal stromal tumors （GISTs）. METHODS： The int...AIM： To explore the relationship between clinicobiological behavior and the expression levels of telomerase activity, apoptosis, p53 gene and bcl-2 gene in gastrointestinal stromal tumors （GISTs）. METHODS： The intensity of telomerase activity, apoptosis, p53 and bcl-2 expression in GISTs were detected by telomeric repeat amplification protocol, in situ end-labeling technique, and immunohistochemistry, respectively. RESULTS： The positive rates of telomerase activity of malignant GIST, potential malignant GIST and benign GIST were 85% （17/20）, 22.8% （2/9） and 0 （0/9）, respectively. The apoptosis indices of malignant GIST, potential malignant GIST, and benign GIST were 11.7±5.4, 30.2±5.6 and 45.2 ±7.2, respectively. The intensity of telomerase activity and apoptosis were related to the biological characteristics of GISTs （85% vs 22.8%, 0, 0; P 〈 0.01 or 11.7±5.4 vs 30.2±5.6, 45.2±7.2, 72.1±9.3; P 〈 0.05）. The intensity of telomerase activity was negatively correlated with cellular apoptosis （22.9±8.4 vs 9.5±5.7, P 〈 0.01）. The intensity of telomerase activity was positively correlated with/753, bcl-2 expression （40.0% vs 78.9%, 40.0% vs 84.2%; P 〈 0.05）. CONCLUSION： The detection of telomerase activity, apoptosis and its control genes in GIST will be helpful for the discrimination of the malignant and benign GIST and evaluation of the prognosis.展开更多
To investigate the expression of Bcl-2 and Bcl-xl gene in sensitive (A2780) and drug-resistance (AD6) human ovarian cancer cell lines and explore the molecular mechanism of multidrug resistance, A2780 and AD6 were det...To investigate the expression of Bcl-2 and Bcl-xl gene in sensitive (A2780) and drug-resistance (AD6) human ovarian cancer cell lines and explore the molecular mechanism of multidrug resistance, A2780 and AD6 were detected by using DNA gel electrophoresis, flow cytometry and RT-PCR. Our results showed that (1)'DNA ladder ' was observed in A2780 and AD6 after cisplatin treatment; (2) after 3.0, 6.0, 9.9 μg/ml of cisplatin treatment, a significant difference was noted in the rate of apoptosis between in A2780 and AD6 (P<0.05); (3) Bcl-2 and Bcl-xl genes were overexpressed in AD6. After cisplatin treatment, the expression of Bcl-2 and Bcl-xl genes was down-regulated in A2780 and AD6. It is concluded that cisplatin could induce the apoptosis of ovarian cancer cells, and the over-expression of Bcl-2 and Bcl-xl genes may contribute to apoptotic inhibition and the development of multidrug-resistance of human ovarian cancer.展开更多
Objective To study the protective effect of volatile anesthetics, isoflurane and sevoflurane, on ischemic neurons after cerebral ischemia-reperfusion in rats and its possible molecular mechanism. Methods Rat cerebral ...Objective To study the protective effect of volatile anesthetics, isoflurane and sevoflurane, on ischemic neurons after cerebral ischemia-reperfusion in rats and its possible molecular mechanism. Methods Rat cerebral ischemia-reperfusion model was developed by occlusion of the middle cerebral artery （MCA） and bilateral common carotid arteries （CCAs） 1 h after reperfusion. Using flow cytometry （FCM） and Northern blot hybridization, we calculated the number of apoptotic bodies and detected the expression of bcl-2 mRNA and interleukin-113 converting enzyme （ICE） mRNA. Results The apoptotic bodies in hippocampus analyzed by FCM peaked at appeared 24 h after reperfusion, and decreased about 54% and 40%, respectively, after treatment with isoflurane and sevoflurane, as compared with ischemic group. There was no significant difference in the expression of bcl-2 mRNA and ICE mRNA between the inhaled anesthetic groups and ischemic group in hippocampus 24 h after MCA/CCAs occlusion. Conclusion Isoflurane and sevoflurane partially inhibit apoptosis but have no significant effect on the expression of bcl-2 and ICE genes.展开更多
Objective To investigate the significance of overexpression of p5s and bcl-2 protein in carcinogene- sis of cervix. Methods 10 cases of cervical intraepithelial neoplasis(CIN) and 57 cases of invasive cancer were in- ...Objective To investigate the significance of overexpression of p5s and bcl-2 protein in carcinogene- sis of cervix. Methods 10 cases of cervical intraepithelial neoplasis(CIN) and 57 cases of invasive cancer were in- vestigated with immunohistochemistry technique. Results The overexpresion or P53 protein ir CIN and cervical can- cer was significantly higher than that or control, respectively (P<0.01). But there was no significant difference be- tween CIN and cervical cancer(P>0.05). The immunoreactivity of bcl-2 in CIN was much more higher than that of control (P<0.05). The positive rate and immunoreactivity of bcl-2 in cervical carcinoma were both remarkably high- er than those of control (P<0.0l),but there was no significant difference between CIN and cervical carcinoma (P> 0.05). It was also found that there was a remarkably positive correlation between the overexpression of bcl-2 and P53 (P<0.01). Conclusion Because of the loss of wtP53 function,the expression of bcl-2 can not be down-reguated, which is associated with the pathogenesis and development of cervical carcinoma.展开更多
Neurite outgrowth and synaptogenesis are critical steps for functional recovery following ischemic stroke.Damaged axons of the central nervous system in adult mammals exhibit limited regenerative capacity,resulting in...Neurite outgrowth and synaptogenesis are critical steps for functional recovery following ischemic stroke.Damaged axons of the central nervous system in adult mammals exhibit limited regenerative capacity,resulting in enduring neurological deficits.Recent findings from our research indicate that inhibition of Rho-associated kinase(ROCK)2 facilitates neuroprotection in different models of central nervous system diseases.In addition,our prior studies have demonstrated that axonal protection enhances the regeneration of injured axons.However,it remains unclear whether the axonal protection mediated by ROCK2 inhibition also facilitates synaptogenesis.In this study,we aimed to investigate the effects of inhibiting ROCK2 expression on synaptogenesis and neurogenesis in ischemic stroke using an shRNA-expressing adeno-associated virus(AAV)vector(AAV-sh.ROCK2).We demonstrated that AAV-sh.ROCK2 increased neurite outgrowth and facilitated synaptogenesis in vivo.Furthermore,AAV-sh.ROCK2 increased neuronal survival and promoted neurogenesis following middle cerebral artery occlusion surgery as well as long-term motor functional recovery after ischemia/reperfusion injury.Notably,AAV-sh.ROCK2 also stimulated serotonergic and dopaminergic axon sprouting after ischemia/reperfusion injury.Mechanistically,AAV-sh.ROCK2 activity resulted in increased anti-collapsin response mediator protein 2 activation and reductions in RhoA and ROCK2 expression.Our study identified ROCK2 as a critical regulator of synaptogenesis and neurogenesis,highlighting it as a promising target to facilitate neuroprotection and regeneration in ischemic stroke.展开更多
To investigate the expression of Bcl-2 and Survivin and HPV16/18 infection in uterine cervical carcinogenesis, formalin-fixed, paraffin-embedded specimens from cervical carcinomas, cervical intraepithelial neoplasia ...To investigate the expression of Bcl-2 and Survivin and HPV16/18 infection in uterine cervical carcinogenesis, formalin-fixed, paraffin-embedded specimens from cervical carcinomas, cervical intraepithelial neoplasia （C1N） and normal cervical tissues were studied. Using streptavidin-biotin peroxidase （S- P） immunohistochemical technique, the authors examined the expression of Bcl-2 and Survivin in these specimens. The number of apoptosis cells was assessed in situ by TdT-mediated dUTP-biotin end labeling （TUNEL） method. The infection of HPV type 16, 18 DNA were determined by PCR. It was found that there were significant differences in Bcl-2, Survivin and apoptotic index （AI） between cervical carcinomas, CIN and normal cervical tissues, respectively. Expression of Bcl-2 and AI were correlated with tu- mor grades, clinical stages and lymph node metastasis and expression of Survivin was associated with tu- mor grades and lymph node metastasis. There were different positive rate of HPV^s between cervical car- cinomas, C1N and normal tissues and were not associated with tumor grades, clinical stages and lymph node metastasis. The infection of HPV16/18 was associated with the expression of Bcl-2, Survivin and AI, respectively. It was concluded that the abnormal expression of Bcl-2, Survivin and infection of HPV16/18 were associated with cervical carcinomas. They possibly can be useful indexes for the primary screening and prognosis of cervical carcinomas.展开更多
To explore the role of bcl-2 and bax genes in the apoptosis of human U937 cells induced by E.coli, flow cytometry assay with annexinⅤ-FITC/PI double staining was used to determine the condition of apoptosis, and the ...To explore the role of bcl-2 and bax genes in the apoptosis of human U937 cells induced by E.coli, flow cytometry assay with annexinⅤ-FITC/PI double staining was used to determine the condition of apoptosis, and the expressions of mRNA of bcl-2 and bax genes were assayed with RT-PCR. It was found that the apoptosis of human U937 cells could be induced by E.coli at various concentration ratios between cells and bacteria for 30 min in a dose-dependent manner. The apoptotic rates at cell/bacteria ratios of 0, 1∶5, 1∶10, 1∶20, 1∶50 and 1∶100 were 3.16%±0.90%, 9.46%±0.84%, 17.90%±1.41%, 35.59%±3.76%, 38.35%±7.12% and 55.07%±5.82% respectively. Also, there was a tendency of alterations in the expression levels of bcl-2 and bax genes with an increased expression level of bax gene and a reduced expression level of bcl-2 gene. It is concluded that E.coli can induce apoptosis in human U937 cells with a down-regulated expression of Bcl-2 and an up-regulated expression of Bax, and this might be related to the induction of apoptosis of the infected cell.展开更多
文摘Objective:Autophagy is a programmed cell death procedure,which has essential functions in tumorigenesis.However,its temporal expression and function under different status are yet to be determined.This study aims to investigate the temporal expression of autophagy and its possible function in 7,12-dimethylbenz[a]anthracene(DMBA)-induced hamster buccal-pouch cancer model(HBPCM).Methods:A total of 50 hamster buccal-pouch tumorigenesis models were established by painting DMBA for 4,8,10 and 13 weeks.The expression and subcellular localization of LC3,Beclin 1 and Bcl-2 in buccal lesions were evaluated by immunohistochemical staining and Western blotting.DNA damage was observed by immunohistochemical staining of 8-oHdG.The relationship between Beclin 1 and Bcl-2 was analyzed by immunofluorescence colocalization.Results:The expression levels of LC3 and Beclin 1 associated with autophagy in the experimental buccal pouch of HBPCM were significantly upregulated after 4 weeks(P<0.05),but gradually downregulated after 13 weeks of HBPCM induction.By contrast,the expression level of Bcl-2 was significantly upregulated after 13 weeks.The co-localized regions of Bcl-2 and Beclin 1 peaked after 4 weeks and then decreased gradually.The DNA damage in epithelial cells increased slightly after 4 weeks,and then rapidly decreased over the next 2 months.Conclusion:Autophagy is motivated by a tumor suppressor that diminishes carcinogen-induced DNA damage.However,autophagy is gradually suppressed,which may be attributed to the interaction between Bcl-2 and Beclin 1.This result indicates that the promotion of autophagy may suppress malignant transformation and provide new insights on future potential treatments of HBPCM.
文摘To evaluate the apoptosis positivity, the expression of Bcl-2, bax proteinsin 30 patients with squamous cell cervix carcinoma before and after radiotherapy. Methods: By usingimmuno-histochemical and TDT-dUTP nick end labelling techniques, 30 cases of squamous cell cervicalcarcinoma were analyzed. Results: The apoptosis positivity before and after irradiation was 76.7%and 100% respectively, with the difference being significant (P 【 0.05); The positive rates of Bcl-2protein before and after irradiation were 73.3% and 46.7% respectively, with the difference beingsignificant (P 【 0.05); The positive rates of bax protein before and after irradiation were 86% and100% respectively, with the difference being significant (P 【 0.05). Conclusion: bax and Bcl-2protein play an important role in apoptosis induced by fractionated radiation therapy. Apoptosisinduced by irradiation is contributed to upregulation of bax protein or downregulation of Bcl-2protein.
文摘AIM： To explore the relationship between clinicobiological behavior and the expression levels of telomerase activity, apoptosis, p53 gene and bcl-2 gene in gastrointestinal stromal tumors （GISTs）. METHODS： The intensity of telomerase activity, apoptosis, p53 and bcl-2 expression in GISTs were detected by telomeric repeat amplification protocol, in situ end-labeling technique, and immunohistochemistry, respectively. RESULTS： The positive rates of telomerase activity of malignant GIST, potential malignant GIST and benign GIST were 85% （17/20）, 22.8% （2/9） and 0 （0/9）, respectively. The apoptosis indices of malignant GIST, potential malignant GIST, and benign GIST were 11.7±5.4, 30.2±5.6 and 45.2 ±7.2, respectively. The intensity of telomerase activity and apoptosis were related to the biological characteristics of GISTs （85% vs 22.8%, 0, 0; P 〈 0.01 or 11.7±5.4 vs 30.2±5.6, 45.2±7.2, 72.1±9.3; P 〈 0.05）. The intensity of telomerase activity was negatively correlated with cellular apoptosis （22.9±8.4 vs 9.5±5.7, P 〈 0.01）. The intensity of telomerase activity was positively correlated with/753, bcl-2 expression （40.0% vs 78.9%, 40.0% vs 84.2%; P 〈 0.05）. CONCLUSION： The detection of telomerase activity, apoptosis and its control genes in GIST will be helpful for the discrimination of the malignant and benign GIST and evaluation of the prognosis.
基金ThisprojectwassupportedbytheNationalNaturalScienceFoun dationofChina (No .30 0 70 786 )andagrantfromtheScientificandTechnologicalDevelopmentPlanofHubeiProvince (No .2 0 0 0 1P15 0 5 )
文摘To investigate the expression of Bcl-2 and Bcl-xl gene in sensitive (A2780) and drug-resistance (AD6) human ovarian cancer cell lines and explore the molecular mechanism of multidrug resistance, A2780 and AD6 were detected by using DNA gel electrophoresis, flow cytometry and RT-PCR. Our results showed that (1)'DNA ladder ' was observed in A2780 and AD6 after cisplatin treatment; (2) after 3.0, 6.0, 9.9 μg/ml of cisplatin treatment, a significant difference was noted in the rate of apoptosis between in A2780 and AD6 (P<0.05); (3) Bcl-2 and Bcl-xl genes were overexpressed in AD6. After cisplatin treatment, the expression of Bcl-2 and Bcl-xl genes was down-regulated in A2780 and AD6. It is concluded that cisplatin could induce the apoptosis of ovarian cancer cells, and the over-expression of Bcl-2 and Bcl-xl genes may contribute to apoptotic inhibition and the development of multidrug-resistance of human ovarian cancer.
基金This work was supported by National Natural Science Foundation (No. 39870786)
文摘Objective To study the protective effect of volatile anesthetics, isoflurane and sevoflurane, on ischemic neurons after cerebral ischemia-reperfusion in rats and its possible molecular mechanism. Methods Rat cerebral ischemia-reperfusion model was developed by occlusion of the middle cerebral artery （MCA） and bilateral common carotid arteries （CCAs） 1 h after reperfusion. Using flow cytometry （FCM） and Northern blot hybridization, we calculated the number of apoptotic bodies and detected the expression of bcl-2 mRNA and interleukin-113 converting enzyme （ICE） mRNA. Results The apoptotic bodies in hippocampus analyzed by FCM peaked at appeared 24 h after reperfusion, and decreased about 54% and 40%, respectively, after treatment with isoflurane and sevoflurane, as compared with ischemic group. There was no significant difference in the expression of bcl-2 mRNA and ICE mRNA between the inhaled anesthetic groups and ischemic group in hippocampus 24 h after MCA/CCAs occlusion. Conclusion Isoflurane and sevoflurane partially inhibit apoptosis but have no significant effect on the expression of bcl-2 and ICE genes.
文摘Objective To investigate the significance of overexpression of p5s and bcl-2 protein in carcinogene- sis of cervix. Methods 10 cases of cervical intraepithelial neoplasis(CIN) and 57 cases of invasive cancer were in- vestigated with immunohistochemistry technique. Results The overexpresion or P53 protein ir CIN and cervical can- cer was significantly higher than that or control, respectively (P<0.01). But there was no significant difference be- tween CIN and cervical cancer(P>0.05). The immunoreactivity of bcl-2 in CIN was much more higher than that of control (P<0.05). The positive rate and immunoreactivity of bcl-2 in cervical carcinoma were both remarkably high- er than those of control (P<0.0l),but there was no significant difference between CIN and cervical carcinoma (P> 0.05). It was also found that there was a remarkably positive correlation between the overexpression of bcl-2 and P53 (P<0.01). Conclusion Because of the loss of wtP53 function,the expression of bcl-2 can not be down-reguated, which is associated with the pathogenesis and development of cervical carcinoma.
基金supported by the National Natural Science Foundation of China,No.82471327the Natural Science Foundation of ShandongProvince,No.ZR2024MH200(both to SL).
文摘Neurite outgrowth and synaptogenesis are critical steps for functional recovery following ischemic stroke.Damaged axons of the central nervous system in adult mammals exhibit limited regenerative capacity,resulting in enduring neurological deficits.Recent findings from our research indicate that inhibition of Rho-associated kinase(ROCK)2 facilitates neuroprotection in different models of central nervous system diseases.In addition,our prior studies have demonstrated that axonal protection enhances the regeneration of injured axons.However,it remains unclear whether the axonal protection mediated by ROCK2 inhibition also facilitates synaptogenesis.In this study,we aimed to investigate the effects of inhibiting ROCK2 expression on synaptogenesis and neurogenesis in ischemic stroke using an shRNA-expressing adeno-associated virus(AAV)vector(AAV-sh.ROCK2).We demonstrated that AAV-sh.ROCK2 increased neurite outgrowth and facilitated synaptogenesis in vivo.Furthermore,AAV-sh.ROCK2 increased neuronal survival and promoted neurogenesis following middle cerebral artery occlusion surgery as well as long-term motor functional recovery after ischemia/reperfusion injury.Notably,AAV-sh.ROCK2 also stimulated serotonergic and dopaminergic axon sprouting after ischemia/reperfusion injury.Mechanistically,AAV-sh.ROCK2 activity resulted in increased anti-collapsin response mediator protein 2 activation and reductions in RhoA and ROCK2 expression.Our study identified ROCK2 as a critical regulator of synaptogenesis and neurogenesis,highlighting it as a promising target to facilitate neuroprotection and regeneration in ischemic stroke.
文摘To investigate the expression of Bcl-2 and Survivin and HPV16/18 infection in uterine cervical carcinogenesis, formalin-fixed, paraffin-embedded specimens from cervical carcinomas, cervical intraepithelial neoplasia （C1N） and normal cervical tissues were studied. Using streptavidin-biotin peroxidase （S- P） immunohistochemical technique, the authors examined the expression of Bcl-2 and Survivin in these specimens. The number of apoptosis cells was assessed in situ by TdT-mediated dUTP-biotin end labeling （TUNEL） method. The infection of HPV type 16, 18 DNA were determined by PCR. It was found that there were significant differences in Bcl-2, Survivin and apoptotic index （AI） between cervical carcinomas, CIN and normal cervical tissues, respectively. Expression of Bcl-2 and AI were correlated with tu- mor grades, clinical stages and lymph node metastasis and expression of Survivin was associated with tu- mor grades and lymph node metastasis. There were different positive rate of HPV^s between cervical car- cinomas, C1N and normal tissues and were not associated with tumor grades, clinical stages and lymph node metastasis. The infection of HPV16/18 was associated with the expression of Bcl-2, Survivin and AI, respectively. It was concluded that the abnormal expression of Bcl-2, Survivin and infection of HPV16/18 were associated with cervical carcinomas. They possibly can be useful indexes for the primary screening and prognosis of cervical carcinomas.
文摘To explore the role of bcl-2 and bax genes in the apoptosis of human U937 cells induced by E.coli, flow cytometry assay with annexinⅤ-FITC/PI double staining was used to determine the condition of apoptosis, and the expressions of mRNA of bcl-2 and bax genes were assayed with RT-PCR. It was found that the apoptosis of human U937 cells could be induced by E.coli at various concentration ratios between cells and bacteria for 30 min in a dose-dependent manner. The apoptotic rates at cell/bacteria ratios of 0, 1∶5, 1∶10, 1∶20, 1∶50 and 1∶100 were 3.16%±0.90%, 9.46%±0.84%, 17.90%±1.41%, 35.59%±3.76%, 38.35%±7.12% and 55.07%±5.82% respectively. Also, there was a tendency of alterations in the expression levels of bcl-2 and bax genes with an increased expression level of bax gene and a reduced expression level of bcl-2 gene. It is concluded that E.coli can induce apoptosis in human U937 cells with a down-regulated expression of Bcl-2 and an up-regulated expression of Bax, and this might be related to the induction of apoptosis of the infected cell.
