To examine the role of gap junctions in cell senescence,the changes of gap junctions in cisplatin-induced premature senescence of primary cultured fibroblasts were studied and compared with the replicative senescent h...To examine the role of gap junctions in cell senescence,the changes of gap junctions in cisplatin-induced premature senescence of primary cultured fibroblasts were studied and compared with the replicative senescent human fibroblasts.Dye transfer assay for gap junction function and immunofluorescent staining for connexin 43 protein distribution were done respectively. Furthermore,cytofluorimetry and DAPI fluorescence staining were performed for cell cycle and apoptosis analysis. p53 gene expression level was detected with indirect immunofluorescence. We found that cisplatin (10 mM) treatment could block cell growth cycle at G1 and induced premature senescence. The premature senescence changes included high frequency of apoptosis,elevation of p53 expression,loss of membranous gap junctions and reduction of dye-transfer capacity. These changes were comparable to the changes of replicative senescence of human fibroblasts. It was also concluded that cisplatin could induce premature senescence concomitant with inhibition of gap junctions in the fibroblasts. Loss of functional gap junctions from the cell membrane may account for the reduced intercellular communication in the premature senescent fibroblasts. The cell system we used may provide a model useful for the study of the gap junction thus promoting agents against premature senescence.展开更多
Objective To investigate the role of extracellular regulated kinase (ERK1/2) pathway in cisplatin-induced apoptosis in human ovarian carcinoma cells. Methods Cisplatin-induced apoptosis were stained with DAPI and was ...Objective To investigate the role of extracellular regulated kinase (ERK1/2) pathway in cisplatin-induced apoptosis in human ovarian carcinoma cells. Methods Cisplatin-induced apoptosis were stained with DAPI and was assessed microscopically in human epithelial adenocarcinoma ovarian cell line SKOV3 cells. ERK activation was determined by Western blotting using an anti-phospho-ERK antibody to detect ERK activity. The effect of PD98059 on ERK activity induced by cisplatin was detected by MTT assay. Results Marked apoptosis of SKOV3 cells resulted from 48 hours treatment with 20 μg/mL cisplatin. Strong activation of ERK was led to by 15 μg/mL cisplatin. Dose response and time course of cisplatin induced apoptosis in SKOV3 cells. Cisplatin-induced ERK activation occurred at 12 hours and increased to highest induction at 24 hours by Western blotting. The effect of PD 98059 on ERK activity induced by cisplatin at the concentration of 100 μmol/L PD 98059. Statistically significant decreased in cell survival were observed with 100 μmol/L PD 98059 at 15 and 20 μg/mL cisplatin (P< 0.05). Conclusions Cisplatin activates the ERK signaling pathway in ovarian cancer cell line SKOV3. Inhibition of ERK acti-vity enhances sensitivity to cisplatin cytotoxity in ovarian cancer cell line SKOV3. Evaluation of ERK activity could be useful in predicting which ovarian cancer will response most favorably to cisplatin therapy.展开更多
Recognition of DNA damage is a critical step for DNA damage-mediated cellular response. XPC is an important DNA damage recognition protein involved in nucleotide excision repair (NER). We have studied the XPC protein ...Recognition of DNA damage is a critical step for DNA damage-mediated cellular response. XPC is an important DNA damage recognition protein involved in nucleotide excision repair (NER). We have studied the XPC protein in cisplatin DNA damaging treatment-mediated cellular response. Comparison of the microarray data from both normal and XPCdefective human fibroblasts identified 861 XPC-responsive genes in the cisplatin treatment (with minimum fold change≥1.5).The cell cycle and cell proliferation-related genes are the most affected genes by the XPC defect in the treatment. Many other cellular function genes, especially the DNA repair and signal transduction-related genes, were also affected by the XPC defect in the treatment. To validate the microarray data, the transcription levels of some microarray-identified genes were also determined by an RT-PCR based real time PCR assay. The real time PCR results are consistent with the microarray data for most of the tested genes, indicating the reliability of the microarray data. To further validate the microarray data, the cisplatin treatment-mediated caspase-3 activation was also determined. The Western blot hybridization results indicate that the XPC defect greatly attenuates the cisplatin treatment-mediated Caspase-3 activation. We elucidated the role of p53 protein in the XPC protein DNA damage recognition-mediated signaling process. The XPC defect reduces the cisplatin treatment-mediated p53 response. These results suggest that the XPC protein plays an important role in the cisplatin treatment-mediated cellular response. It may also suggest a possible mechanism of cancer cell drug resistance.展开更多
OBJECTIVE To study the mechanism of apoptosis induced by cisplatin in vitro in HeLa cells cervical cancer cell line. METHODS The inhibitory effect of cisplatin on HeLa cell growth was analyzed by the MTT assay. Cell a...OBJECTIVE To study the mechanism of apoptosis induced by cisplatin in vitro in HeLa cells cervical cancer cell line. METHODS The inhibitory effect of cisplatin on HeLa cell growth was analyzed by the MTT assay. Cell apoptosis was measured with flow cytometry and Hoechst 33258 staining following cisplatin treatment. The effect of cisplatin on transcription of HPV E6 was analyzed by RT-PCR and protein expression of E6, P53, p21, Bax and Bcl-2 was studied by Western blots. RESULTS Cisplatin inhibited cellular proliferation in a time and dose- dependant manner. The sub-G1 peak by flow cytometry showed a higher apoptotic rate in the experimental group compared to the controls and Hoechst 33258 staining indicated that apoptosis was induced by cisplatin. Results of RT-PCR demonstrated that cisplatin decreased tran- scription of E6. Western Blots showed that cisplatin decreased protein expression of E6 and increased protein expression of P53, p21 and Bax but had no effect on protein expression of Bcl-2. CONCLUSION Cisplatin induces apoptosis and death of HeLa cells through the suppression of HPV E6 and restoration of p53 function.展开更多
基金supported by grants from The National Key Program for Basic Research,Project No.G2000057002National Natural Science Foudation of China,Project No.30270685
文摘To examine the role of gap junctions in cell senescence,the changes of gap junctions in cisplatin-induced premature senescence of primary cultured fibroblasts were studied and compared with the replicative senescent human fibroblasts.Dye transfer assay for gap junction function and immunofluorescent staining for connexin 43 protein distribution were done respectively. Furthermore,cytofluorimetry and DAPI fluorescence staining were performed for cell cycle and apoptosis analysis. p53 gene expression level was detected with indirect immunofluorescence. We found that cisplatin (10 mM) treatment could block cell growth cycle at G1 and induced premature senescence. The premature senescence changes included high frequency of apoptosis,elevation of p53 expression,loss of membranous gap junctions and reduction of dye-transfer capacity. These changes were comparable to the changes of replicative senescence of human fibroblasts. It was also concluded that cisplatin could induce premature senescence concomitant with inhibition of gap junctions in the fibroblasts. Loss of functional gap junctions from the cell membrane may account for the reduced intercellular communication in the premature senescent fibroblasts. The cell system we used may provide a model useful for the study of the gap junction thus promoting agents against premature senescence.
基金Supported by Heilongjiang Province Natural Science Funds (D03-55) and Heilongjiang Province Sanitary Bureau Science Funds (2003-003)
文摘Objective To investigate the role of extracellular regulated kinase (ERK1/2) pathway in cisplatin-induced apoptosis in human ovarian carcinoma cells. Methods Cisplatin-induced apoptosis were stained with DAPI and was assessed microscopically in human epithelial adenocarcinoma ovarian cell line SKOV3 cells. ERK activation was determined by Western blotting using an anti-phospho-ERK antibody to detect ERK activity. The effect of PD98059 on ERK activity induced by cisplatin was detected by MTT assay. Results Marked apoptosis of SKOV3 cells resulted from 48 hours treatment with 20 μg/mL cisplatin. Strong activation of ERK was led to by 15 μg/mL cisplatin. Dose response and time course of cisplatin induced apoptosis in SKOV3 cells. Cisplatin-induced ERK activation occurred at 12 hours and increased to highest induction at 24 hours by Western blotting. The effect of PD 98059 on ERK activity induced by cisplatin at the concentration of 100 μmol/L PD 98059. Statistically significant decreased in cell survival were observed with 100 μmol/L PD 98059 at 15 and 20 μg/mL cisplatin (P< 0.05). Conclusions Cisplatin activates the ERK signaling pathway in ovarian cancer cell line SKOV3. Inhibition of ERK acti-vity enhances sensitivity to cisplatin cytotoxity in ovarian cancer cell line SKOV3. Evaluation of ERK activity could be useful in predicting which ovarian cancer will response most favorably to cisplatin therapy.
文摘Recognition of DNA damage is a critical step for DNA damage-mediated cellular response. XPC is an important DNA damage recognition protein involved in nucleotide excision repair (NER). We have studied the XPC protein in cisplatin DNA damaging treatment-mediated cellular response. Comparison of the microarray data from both normal and XPCdefective human fibroblasts identified 861 XPC-responsive genes in the cisplatin treatment (with minimum fold change≥1.5).The cell cycle and cell proliferation-related genes are the most affected genes by the XPC defect in the treatment. Many other cellular function genes, especially the DNA repair and signal transduction-related genes, were also affected by the XPC defect in the treatment. To validate the microarray data, the transcription levels of some microarray-identified genes were also determined by an RT-PCR based real time PCR assay. The real time PCR results are consistent with the microarray data for most of the tested genes, indicating the reliability of the microarray data. To further validate the microarray data, the cisplatin treatment-mediated caspase-3 activation was also determined. The Western blot hybridization results indicate that the XPC defect greatly attenuates the cisplatin treatment-mediated Caspase-3 activation. We elucidated the role of p53 protein in the XPC protein DNA damage recognition-mediated signaling process. The XPC defect reduces the cisplatin treatment-mediated p53 response. These results suggest that the XPC protein plays an important role in the cisplatin treatment-mediated cellular response. It may also suggest a possible mechanism of cancer cell drug resistance.
文摘OBJECTIVE To study the mechanism of apoptosis induced by cisplatin in vitro in HeLa cells cervical cancer cell line. METHODS The inhibitory effect of cisplatin on HeLa cell growth was analyzed by the MTT assay. Cell apoptosis was measured with flow cytometry and Hoechst 33258 staining following cisplatin treatment. The effect of cisplatin on transcription of HPV E6 was analyzed by RT-PCR and protein expression of E6, P53, p21, Bax and Bcl-2 was studied by Western blots. RESULTS Cisplatin inhibited cellular proliferation in a time and dose- dependant manner. The sub-G1 peak by flow cytometry showed a higher apoptotic rate in the experimental group compared to the controls and Hoechst 33258 staining indicated that apoptosis was induced by cisplatin. Results of RT-PCR demonstrated that cisplatin decreased tran- scription of E6. Western Blots showed that cisplatin decreased protein expression of E6 and increased protein expression of P53, p21 and Bax but had no effect on protein expression of Bcl-2. CONCLUSION Cisplatin induces apoptosis and death of HeLa cells through the suppression of HPV E6 and restoration of p53 function.
