Objective The compound 2,3,7,8-tetrachlorodibenzo-p-dioxin(TCDD), a persistent organic pollutant, is harmful to the nervous system, but its effects on the brain are still unclear. This study aimed to investigate the e...Objective The compound 2,3,7,8-tetrachlorodibenzo-p-dioxin(TCDD), a persistent organic pollutant, is harmful to the nervous system, but its effects on the brain are still unclear. This study aimed to investigate the effects of TCDD on astrocytes proliferation and underlying molecular mechanism. Methods The cell proliferation was measured by EdU-based proliferation assay and PI staining by flow cytometry. Protein expression levels were detected by Western blotting. Immunofluorescence, cytoplasmic and nuclear fractions separation were used to assess the distribution of signal transducer and activator of transcription 3(STAT3). Results C6 cells treated with 10 and 50 nmol/L TCDD for 24 h showed significant promotion of the proliferation of. The exposure to TCDD resulted in the upregulation in the expression levels of phosphorylated protein kinase B(p-Akt), phosphorylated STAT3, and cyclin D1 in a dose-and time-dependent manner. The inhibition of Akt expression with LY294002 or STAT3 expression with AG490 abolished the TCDD-induced cyclin D1 upregulation and cell proliferation. Furthermore, LY294002 suppressed the activation of STAT3. Finally, TCDD promoted the translocation of STAT3 from the cytoplasm to the nucleus, and LY294002 treatment blocked this effect. Conclusion TCDD exposure promotes the proliferation of astrocyte cells via the Akt/STAT3/cyclin D1 pathway, leading to astrogliosis.展开更多
Objective To study the molecular mechanism of the inhibitory effects of vitamin C on benzo[a]pyrene （B[a]P）-induced changes of cell cycle in human embryo lung fibroblast （HELF） cells. Methods The stable transfecta...Objective To study the molecular mechanism of the inhibitory effects of vitamin C on benzo[a]pyrene （B[a]P）-induced changes of cell cycle in human embryo lung fibroblast （HELF） cells. Methods The stable transfectants, HELF transfected with antisense cyclin D1 and antisense CDK4, were established. Cells were cultured and pretreated with vitamin C before stimulation with B[a]P for 24 h. The expression levels of cyclin DI, CDK4, E2FI, and E2F4 were determined by Western blot. Flow cytometric analysis was employed to detect the distributions of cell cycle. Results B[a]P significantly elevated the expression levels of cyclin D 1, E2F1, and E2F4 in HELF cells. Vitamin C decreased the expression levels of cyclin D 1, E2F1, and E2F4 in B [a]P-stimulated HELF cells. Dose-dependent relationships were not found between the different concentrations of vitamin C （10, 100, 500, 1000, and 5000 lamol/L） and the expression levels of cyclin D 1, E2F1, and E2F4 in HELF cells. The expression levels of cyclin D1, E2FI, and E2F4 in B[a]P-treated transfectants were lower than those in B[a]P-treated HELF cells. The expression levels of cyclin DI and E2F4 treated with vitamin C and antisense cyclin D1 were decreased compared with those treated with antisense cyclin DI alone. The effects of vitamin C combined with antisense CDK4 on the expression levels of cyclin DI and E2FI/E2F4 were similar to those of antisense CDK4 alone. B[a]P progressed HELF cells from GI to S phase. Both vitamin C and antisense cyclin DI suppressed the changes of cell cycle progressed by B[a]P. However, antisense CDK4 did not attenuate the above changes. Vitamin C combined with antisense CDK4 markedly suppressed B[a]P-induced changes of cell cycle as compared with antisense CDK4. But the inhibitory effects of vitamin C combined with antisense cyclin DI on B[a]P-induced changes of cell cycle were similar to those of vitamin C alone or antisense cyclin DI alone. Conclusions B[a]P progressed HELF cells from G1 to S phase via intracellular signaling pathway of cyclin D I/E2F. Vitamin C may modulate this signaling pathway to protect cells from injury caused by B[a]P.展开更多
目的分析磷酸化转录信号转导子及激活子3(phosphorylated signal transducer and activator of transcription-3,p-STAT3)/磷酸化蛋白激酶B(phosphorylated protein kinase B,p-AKT)信号通路及其靶基因细胞周期素D1(cyclinD1)在基底细胞...目的分析磷酸化转录信号转导子及激活子3(phosphorylated signal transducer and activator of transcription-3,p-STAT3)/磷酸化蛋白激酶B(phosphorylated protein kinase B,p-AKT)信号通路及其靶基因细胞周期素D1(cyclinD1)在基底细胞癌(basal cell carcinoma,BCC)皮损中的表达及其临床意义。方法选取2010年1月—2019年8月在山东省济南市人民医院皮肤科就诊且经组织病理及免疫组化确诊为BCC的60例患者石蜡标本,以及在本院接受外科整形手术并留存的正常皮肤组织标本的患者,分别纳入BBC组及正常组。分别采用免疫组化法、PCR法、Western印迹实验检测皮损处p-STAT3、p-AKT及cyclinD1表达,并分析BCC患者皮损处p-STAT3 mRNA、p-AKT mRNA、cyclinD1 mRNA与临床病理的关系。结果BCC组p-STAT3、p-AKT、cyclinD1平均光密度值,p-STAT3 mRNA、p-AKT mRNA、cyclinD1 mRNA及p-STAT3蛋白、p-AKT蛋白、cyclinD1蛋白表达显著高于正常组(P<0.05);且IBCC型BCC患者皮损中p-STAT3 mRNA、p-AKT mRNA、cyclinD1 mRNA表达显著高于NIBCC患者(P<0.05);BCC皮损中p-STAT3 mRNA、p-AKT mRNA、cyclinD1 mRNA表达与病理类型有显著相关性(P<0.01)。结论BCC皮损处存在p-STAT3、p-AKT、cyclinD1高表达现象,且IBCC型BCC患者皮损处p-STAT3 mRNA、p-AKT mRNA、cyclinD1 mRNA表达更高,值得临床重视。展开更多
Objective: To study the influence of neoadjuvant chemotherapy on the expression of cyclin D1, Bcl-2, PCNA and P- gp in osteosarcoma cells and the relationship between the expression and tumor cell necrosis rate (TCNR)...Objective: To study the influence of neoadjuvant chemotherapy on the expression of cyclin D1, Bcl-2, PCNA and P- gp in osteosarcoma cells and the relationship between the expression and tumor cell necrosis rate (TCNR) after chemotherapy. Methods: By using immunohistochemistry, the expression of cyclin D1, Bcl-2, PCNA and P-gp was detected in 23 cases of osteosarcoma and TCNR were calculated. Results: The pre-chemotherapy positive expression rate of cyclin D1, Bcl-2, PCNA and P-gp was 73.9%, 69.6%, 91.3% and 21.7%, respectively, and that post-chemotherapy positive expression rate was 52.1%, 34.8%, 43.5% and 56.5%, respectively. The positive expression rate of Bcl-2 and PCNA after chemotherapy was much lower than that before chemotherapy (P=0.039, 0.034). After chemotherapy, the expression rate of P-gp was higher (P=0.021) and the expression of cyclin D1 had no statistically significant difference (P=0.180) comparing with that before chemotherapy. No correla- tion existed between the expression of cyclin D1, Bcl-2, PCNA, P-gp and TCNR before chemotherapy (P=0.155, 0.371, 1.000 and 0.640). There was a negative correlation between the expression of Bcl-2, PCNA, P-gp and TCNR (P=0.009, 0.012 and 0.015), but no relationship existed between the cyclin D1 and TCNR (P=0.100) after chemotherapy. Conclusion: Chemotherapy could inhibit proliferation and induce apoptosis of osteosarcoma cells. At the same time, due to the overexpression of the P-gp, the drug resistance of the osteosarcoma cells was increased. The detection of cyclin D1, Bcl-2, PCNA and P-gp in osteosarcoma samples before chemotherapy might not be used to predict the curative effect of the chemotherapy.展开更多
基金supported by the National Natural Science Foundation of China [No.21477058,81703255]Nantong Jiangsu scientific research project [MS12017014-8]
文摘Objective The compound 2,3,7,8-tetrachlorodibenzo-p-dioxin(TCDD), a persistent organic pollutant, is harmful to the nervous system, but its effects on the brain are still unclear. This study aimed to investigate the effects of TCDD on astrocytes proliferation and underlying molecular mechanism. Methods The cell proliferation was measured by EdU-based proliferation assay and PI staining by flow cytometry. Protein expression levels were detected by Western blotting. Immunofluorescence, cytoplasmic and nuclear fractions separation were used to assess the distribution of signal transducer and activator of transcription 3(STAT3). Results C6 cells treated with 10 and 50 nmol/L TCDD for 24 h showed significant promotion of the proliferation of. The exposure to TCDD resulted in the upregulation in the expression levels of phosphorylated protein kinase B(p-Akt), phosphorylated STAT3, and cyclin D1 in a dose-and time-dependent manner. The inhibition of Akt expression with LY294002 or STAT3 expression with AG490 abolished the TCDD-induced cyclin D1 upregulation and cell proliferation. Furthermore, LY294002 suppressed the activation of STAT3. Finally, TCDD promoted the translocation of STAT3 from the cytoplasm to the nucleus, and LY294002 treatment blocked this effect. Conclusion TCDD exposure promotes the proliferation of astrocyte cells via the Akt/STAT3/cyclin D1 pathway, leading to astrogliosis.
基金This work was supported by grants of National Natural Science Foundation of China (30371206, 30440420593), 973 National Key Basic Research and Development Program (2002 CB 512905) and Taishan Charitable Association LTD. HK.
文摘Objective To study the molecular mechanism of the inhibitory effects of vitamin C on benzo[a]pyrene （B[a]P）-induced changes of cell cycle in human embryo lung fibroblast （HELF） cells. Methods The stable transfectants, HELF transfected with antisense cyclin D1 and antisense CDK4, were established. Cells were cultured and pretreated with vitamin C before stimulation with B[a]P for 24 h. The expression levels of cyclin DI, CDK4, E2FI, and E2F4 were determined by Western blot. Flow cytometric analysis was employed to detect the distributions of cell cycle. Results B[a]P significantly elevated the expression levels of cyclin D 1, E2F1, and E2F4 in HELF cells. Vitamin C decreased the expression levels of cyclin D 1, E2F1, and E2F4 in B [a]P-stimulated HELF cells. Dose-dependent relationships were not found between the different concentrations of vitamin C （10, 100, 500, 1000, and 5000 lamol/L） and the expression levels of cyclin D 1, E2F1, and E2F4 in HELF cells. The expression levels of cyclin D1, E2FI, and E2F4 in B[a]P-treated transfectants were lower than those in B[a]P-treated HELF cells. The expression levels of cyclin DI and E2F4 treated with vitamin C and antisense cyclin D1 were decreased compared with those treated with antisense cyclin DI alone. The effects of vitamin C combined with antisense CDK4 on the expression levels of cyclin DI and E2FI/E2F4 were similar to those of antisense CDK4 alone. B[a]P progressed HELF cells from GI to S phase. Both vitamin C and antisense cyclin DI suppressed the changes of cell cycle progressed by B[a]P. However, antisense CDK4 did not attenuate the above changes. Vitamin C combined with antisense CDK4 markedly suppressed B[a]P-induced changes of cell cycle as compared with antisense CDK4. But the inhibitory effects of vitamin C combined with antisense cyclin DI on B[a]P-induced changes of cell cycle were similar to those of vitamin C alone or antisense cyclin DI alone. Conclusions B[a]P progressed HELF cells from G1 to S phase via intracellular signaling pathway of cyclin D I/E2F. Vitamin C may modulate this signaling pathway to protect cells from injury caused by B[a]P.
文摘Objective: To study the influence of neoadjuvant chemotherapy on the expression of cyclin D1, Bcl-2, PCNA and P- gp in osteosarcoma cells and the relationship between the expression and tumor cell necrosis rate (TCNR) after chemotherapy. Methods: By using immunohistochemistry, the expression of cyclin D1, Bcl-2, PCNA and P-gp was detected in 23 cases of osteosarcoma and TCNR were calculated. Results: The pre-chemotherapy positive expression rate of cyclin D1, Bcl-2, PCNA and P-gp was 73.9%, 69.6%, 91.3% and 21.7%, respectively, and that post-chemotherapy positive expression rate was 52.1%, 34.8%, 43.5% and 56.5%, respectively. The positive expression rate of Bcl-2 and PCNA after chemotherapy was much lower than that before chemotherapy (P=0.039, 0.034). After chemotherapy, the expression rate of P-gp was higher (P=0.021) and the expression of cyclin D1 had no statistically significant difference (P=0.180) comparing with that before chemotherapy. No correla- tion existed between the expression of cyclin D1, Bcl-2, PCNA, P-gp and TCNR before chemotherapy (P=0.155, 0.371, 1.000 and 0.640). There was a negative correlation between the expression of Bcl-2, PCNA, P-gp and TCNR (P=0.009, 0.012 and 0.015), but no relationship existed between the cyclin D1 and TCNR (P=0.100) after chemotherapy. Conclusion: Chemotherapy could inhibit proliferation and induce apoptosis of osteosarcoma cells. At the same time, due to the overexpression of the P-gp, the drug resistance of the osteosarcoma cells was increased. The detection of cyclin D1, Bcl-2, PCNA and P-gp in osteosarcoma samples before chemotherapy might not be used to predict the curative effect of the chemotherapy.
