Objective： To investigate the specific blockage effect of individual antisense RNA on mutant p53 gene in vitro. Methods： The single strand antisense transcription system containing mt-p53 exon 8 sequence （pGEM3zf（...Objective： To investigate the specific blockage effect of individual antisense RNA on mutant p53 gene in vitro. Methods： The single strand antisense transcription system containing mt-p53 exon 8 sequence （pGEM3zf（＋/-）p53exon8） was constructed. The ligation of antisense RNAwith mt-p53 gene was confirmed by in situ hybridization; MDA-MB-231 human breast cancer cells were transfected with ASp53exon8＇RNA cotionic liposome-mediated. Expression of mt-p53 protein was examined by immunocytochemical staining and Western blot. Cell proliferation was evaluated by MTT assay; Cell cycle distribution was determined by flow cytometry （FCM）; Apoptosis was observed by TUNEL. Results： In transfected MDA-MB-231 cells, hybridization signals were observed in cytoplasm. ASp53exon8＇RNA transfection induced inhibition of cell proliferation, G2/M phase arrest and increasing apoptotic rates. In addition, expression of p53 protein was down-regulated. Conclusion： pGEM3zf（＋/-）p53exon8 was well constructed and ASp53exon8＇RNA can block mt-p53 gene expression specifically and then inhibit MDA-MB-231 cell proliferation in vitro, which may serve as therapeutic means for human malignancy.展开更多
Objective: To study the molecular mechanisms of TNF--a expression induced by lipopolysaccharide (LPS) for exploring novel methods to prevent or treat clinical patients with endotoxic shock. Methods:Protein kinase assa...Objective: To study the molecular mechanisms of TNF--a expression induced by lipopolysaccharide (LPS) for exploring novel methods to prevent or treat clinical patients with endotoxic shock. Methods:Protein kinase assay was used to detect the kinase activity stimulated by LPS; Con focal laser scan technique was used to show the translocation of p38 on the activation; RT PCR and reporter gene system were used to study the molecular mechanism of TNF -a gene transcription. Results: In RAW cells it was found that p38 was activated on the stimulation of LPS. and activated p38 moved into nucleus from cytosol; TNF--a mRNA increased on the stimulation of LPS and the increased promoter transactivity induced by LPS could be inhibited significantly by specific inhibitor for p38. Conclusion: p38 mitogen activated protein kinase (MAPK ) was activated by the stimulation of LPS,which brought about its entry to the nucleus to act on transcription factors to regulate cellular processes. p38 MAPK Is an important regulator of TNF--a gene expression induced by LPS.展开更多
We reported in this manuscript that TGF-beta1 induces apoptosis in AML12 murine hepatocytes, which is associated with the activation of p38 MAPK signaling pathway. SB202190, a specific inhibitor of p38 MAPK, strongly ...We reported in this manuscript that TGF-beta1 induces apoptosis in AML12 murine hepatocytes, which is associated with the activation of p38 MAPK signaling pathway. SB202190, a specific inhibitor of p38 MAPK, strongly inhibited the TGF-beta1-induced apoptosis and PAI-1 promoter activity. Treatment of cells with TGF-beta1 activates p38. Furthermore, over-expression of dominant negative mutant p38 also reduced the TGF-beta1-induced apoptosis. The data indicate that the activation of p38 is involved in TGF-beta1-mediated gene expression and apoptosis.展开更多
p38 regulated/activated protein kinase(PRAK)plays a key role in cell senescence and tumor suppression.The aim of this study was to investigate if PRAK had effect on cell proliferation.The growth of PRAK+/+and PRAK^(–...p38 regulated/activated protein kinase(PRAK)plays a key role in cell senescence and tumor suppression.The aim of this study was to investigate if PRAK had effect on cell proliferation.The growth of PRAK+/+and PRAK^(–/–)mouse embryonicfibroblast(MEF)cells was measured by methylthiazoletetrazolium(MTT)colorimetric assay,and the proportion of the cell number in different phases of the cell cycle was analyzed byflow cytometry.The growth curves showed that the growth rate was notably decreased,and cell double time was elongated in PRAK^(–/–)cells;moreover,the number of PRAK^(–/–)cells was decreased by 44.5%compared with that of PRAK+/+cells cultured for 96 h,suggesting that G2/M transition is inhibited in PRAK^(–/–)cells.Meanwhile,G1/S transition was also inhibited in PRAK^(–/–)cells,observed withflow cytometry analysis.The ratios of G0/G1,G2/M,and S phases of PRAK+/+cells were 44.9%,12.2%,and 42.9%,respec-tively,while those of PRAK^(–/–)cells were 55.3%,7.3%,and 37.4%,respectively.There were 23.1%increase and 12.7%decrease of the number of PRAK^(–/–)cells in G1 and S phases in comparison with that of PRAK+/+cells,respectively.Taken together,PRAK gene knockout in MEF cells leads to cell cycle arrest and proliferation inhibition.展开更多
基金Key Project Fund of Basic Research, Tianjin Municipal Science and Technology Commission (No. 033801511), and the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry (2004–2005).
文摘Objective： To investigate the specific blockage effect of individual antisense RNA on mutant p53 gene in vitro. Methods： The single strand antisense transcription system containing mt-p53 exon 8 sequence （pGEM3zf（＋/-）p53exon8） was constructed. The ligation of antisense RNAwith mt-p53 gene was confirmed by in situ hybridization; MDA-MB-231 human breast cancer cells were transfected with ASp53exon8＇RNA cotionic liposome-mediated. Expression of mt-p53 protein was examined by immunocytochemical staining and Western blot. Cell proliferation was evaluated by MTT assay; Cell cycle distribution was determined by flow cytometry （FCM）; Apoptosis was observed by TUNEL. Results： In transfected MDA-MB-231 cells, hybridization signals were observed in cytoplasm. ASp53exon8＇RNA transfection induced inhibition of cell proliferation, G2/M phase arrest and increasing apoptotic rates. In addition, expression of p53 protein was down-regulated. Conclusion： pGEM3zf（＋/-）p53exon8 was well constructed and ASp53exon8＇RNA can block mt-p53 gene expression specifically and then inhibit MDA-MB-231 cell proliferation in vitro, which may serve as therapeutic means for human malignancy.
文摘Objective: To study the molecular mechanisms of TNF--a expression induced by lipopolysaccharide (LPS) for exploring novel methods to prevent or treat clinical patients with endotoxic shock. Methods:Protein kinase assay was used to detect the kinase activity stimulated by LPS; Con focal laser scan technique was used to show the translocation of p38 on the activation; RT PCR and reporter gene system were used to study the molecular mechanism of TNF -a gene transcription. Results: In RAW cells it was found that p38 was activated on the stimulation of LPS. and activated p38 moved into nucleus from cytosol; TNF--a mRNA increased on the stimulation of LPS and the increased promoter transactivity induced by LPS could be inhibited significantly by specific inhibitor for p38. Conclusion: p38 mitogen activated protein kinase (MAPK ) was activated by the stimulation of LPS,which brought about its entry to the nucleus to act on transcription factors to regulate cellular processes. p38 MAPK Is an important regulator of TNF--a gene expression induced by LPS.
基金grants fromthe Chinese Academy of Sciences (No. KJ951-BI608), the National Natural Sciences FOundation ofChina (No. 39625007 and
文摘We reported in this manuscript that TGF-beta1 induces apoptosis in AML12 murine hepatocytes, which is associated with the activation of p38 MAPK signaling pathway. SB202190, a specific inhibitor of p38 MAPK, strongly inhibited the TGF-beta1-induced apoptosis and PAI-1 promoter activity. Treatment of cells with TGF-beta1 activates p38. Furthermore, over-expression of dominant negative mutant p38 also reduced the TGF-beta1-induced apoptosis. The data indicate that the activation of p38 is involved in TGF-beta1-mediated gene expression and apoptosis.
基金supported by grants from the National Key Basic Research Program(973 Program)of China(No.2002CB513005)Program for Changjiang Scholars and Innovative Research Team in University(PCSIRT,No.IRT0731)+4 种基金National Natural Science Foundation of China(No.30670828No.30572151,No.30700291)Joint Fund of NSFC with the Guangdong Provincial Government(No.U0632004)Project of Science and Technology Program of Guangdong Province(No.A1090202)Project of Science and Technology Program of Guangzhou City(No.2007J1-C0301).
文摘p38 regulated/activated protein kinase(PRAK)plays a key role in cell senescence and tumor suppression.The aim of this study was to investigate if PRAK had effect on cell proliferation.The growth of PRAK+/+and PRAK^(–/–)mouse embryonicfibroblast(MEF)cells was measured by methylthiazoletetrazolium(MTT)colorimetric assay,and the proportion of the cell number in different phases of the cell cycle was analyzed byflow cytometry.The growth curves showed that the growth rate was notably decreased,and cell double time was elongated in PRAK^(–/–)cells;moreover,the number of PRAK^(–/–)cells was decreased by 44.5%compared with that of PRAK+/+cells cultured for 96 h,suggesting that G2/M transition is inhibited in PRAK^(–/–)cells.Meanwhile,G1/S transition was also inhibited in PRAK^(–/–)cells,observed withflow cytometry analysis.The ratios of G0/G1,G2/M,and S phases of PRAK+/+cells were 44.9%,12.2%,and 42.9%,respec-tively,while those of PRAK^(–/–)cells were 55.3%,7.3%,and 37.4%,respectively.There were 23.1%increase and 12.7%decrease of the number of PRAK^(–/–)cells in G1 and S phases in comparison with that of PRAK+/+cells,respectively.Taken together,PRAK gene knockout in MEF cells leads to cell cycle arrest and proliferation inhibition.
