Oil A induces apoptosis of pancreatic cancer cells via caspase activation, redistribution of cell cycle and GADD expression

AIM: To explore the mechanisms of effects of oil A on apoptosis of human pancreatic cancer cells.METHODS: Cellular DNA content was analyzed by flow cytometry. Western blotting was used for caspase-3 and PARP, caspase-7, caspase-9, cytochrome c, Bcl-2, Bax, Mcl-1, cyclinA, cyclin B1, cyclin D1, cyclin E, CDK2, CDK4, CDK6,P21, P27,GADD45, GADD153.RESULTS: The caspase-3, caspase-7, and caspase-9activities were significantly increased as well as the cleavage of caspase-3, downstream substrate poly-ADP ribose polymerase (PARP) was induced. The amount of cytochrome c in the cytosolic fraction was increased, while the amount of cytochrome c in the mitochondrial fraction was decreased after oil A treatment. The anti-apoptosis proteins Bcl-2and Mci-1 were decreased in parallel and Bax increased,indicating that Bcl-2 family proteins-mitochondria-caspase cascade was responsible for oil-induced apoptosis. The proportion of cells in the G0/G1 decreased in MiaPaCa-2and AsPC-1 cells after the treatment of oil A for 24 hours.The number of cells in S phase was increased in two cancer cell lines at 24 hours. Therefore, cells were significantly accumulated in G2/M phase. The cells with a sub-G0/G1DNA content, a hallmark of apoptosis, were seen at 24 hours both in MiaPaCa-2 and AsPC-1 cells following exposure to oil A. The expression of cyclin A and cyclin B1 was slightly decreased and cyclin D1 levels were markedly lowered in MiaPaCa-2 cells. The expression of cyclin A and cyclin B1 was markedly decreased and cyclin D1 levels were slightly lowered in AsPC-1 cells, while cydin E was not affected and the levels of CDK2, CDK4, and CDK6 were unchanged in MiaPaCa-2 and AsPC-1 cells. In response to oil A, P21 expression was increased, but P27 expression was not affected. The expression of both GADD45 and GADD153was increased in two cell lines following oil A treatment.CONCLUSION: Oil A induces apoptosis of pancreatic cancer cells via activating caspase cascade, modifying cell cycle progress and changing cell cycle-regulating proteins and GADD expression.

LTP的研究进展(Ⅱ)——LTP的转基因研究

LTP研究在近十余年来一直是热点课题。尽管LTP是否是学习和记忆的基础仍有争议,肯定性的研究结果日趋增加,所以LTP仍吸引着大量研究工作者。近年来随着分子生物学技术的进步,人们得以借助转基因手段研究疾病相关性基因及其蛋白质,以及不明功能的基因和蛋白。转基因动物模型更是给难以模拟的Alzheimer氏病的研究极大推动。2001年人类基因组序列研究结果报告对医学科学的发展影响深远。应用转基因模型的手段进一步深入各研究领域。近几年来神经工作者借助转基因手段,对LTP的分子机制有了进一步认识。本文概括性介绍了这方面的有趣研究,希望读者能大致了解LTP研究进展,同时领悟转基因技术的推动力。

Red oil A5 inhibits proliferation and induces apoptosis in pancreatic cancer cells

AIM: To study the effect of red oil A5 on pancreatic cancer cells and its possible mechanisms. METHODS: Effect of different concentrations of red oil A5 on proliferation of three pancreatic cancer cell lines, AsPC-1, MiaPaCa-2 and S2013, was measured by 3H-methyl thymidine incorporation. Time-dependent effects of 1:32 000 red oil A5 on proliferation of three pancreatic cancer cell lines, were also measured by ^3H-methyl thymidine incorporation, and Time-course effects of 1:32 000 red oil A5 on cell number.The cells were counted by Z1-Coulter Counter. Fiowcytometric analysis of cellular DNA content in the control and red oil A5 treated AsPC-1, MiaPaCa-2 and $2013 cells,were stained with propidium iodide. TUNEL assay of red oil A5-induced pancreatic cancer cell apoptosis was performed. Western blotting of the cytochrome c protein in AsPC-1, MiaPaCa-2 and $2013 cells treated 24 hours with 1:32 000 red oil A5 was performed. Proteins in cytosolic fraction and in mitochondria fraction were extracted. Proteins extracted from each sample were electrophoresed on SDS-PAGE gels and then were transferred to nitrocellulose membranes. Cytochrome c was identified using a monoclonal cytochrome c antibody. Western blotting of the caspase-3 protein in AsPC-1, MiaPaCa-2 and S2013 cells treated with 1:32 000 red oil A5 for 24 hours was carried out. Proteins in whole cellular lysates were electrophoresed on SDS-PAGE gels and then transferred to nitrocellulose membranes. Caspase-3 was identified using a specific antibody. Western blotting of polyADP ribose polymerase (PARP) protein in AsPC-1, MiaPaCa2 and S2013 cells treated with 1:32 000 red oil A5 for 24 hours was performed. Proteins in whole cellular lysates were separated by electrophoresis on SDS-PAGE gels and then transferred to nitrocellulose membranes. PARP was identified by using a monoclonal antibody. RESULTS: Red oil A5 caused dose- and time-dependent inhibrdon of pancreatic cancer cell proliferation. Propidium iodide DNA staining showed an increase of the sub-G0/G1 cell population. The DNA fragmentation induced by red oil A5 in these three cell lines was confirmed by the TUNEL assayFurthermore, Western blotting analysis indicated that cytochrome c was released from mitochondda to cytosol during apoptosis,and caspase-3 was activated following red oil A5 treatment which was measured by procaspase-3 cleavage and PARP cleavage. CONCLUSION: These findings show that red oil A5 has potent anti-proliferative effects on human pancreatic cancer cells with induction of apoptosis in vitro.

聚集素在前列腺正常、增生、癌组织中的表达及意义

目的 通过检测聚集素 (Clusterin)在前列腺正常、增生、癌变组织中的表达 ,探讨其与前列腺疾病发生发展的关系。 方法 采用免疫组织化学染色法检测 12例正常前列腺组织、15例良性前列腺增生组织 (BPH)、5 6例前列腺癌标本中Clusterin的表达水平。 结果 3种组织中Clusterin的阳性及弱阳性表达率为 81% (67/83 ) ,其中前列腺正常、增生、癌组织中阳性及弱阳性表达率分别为17% (2 /12 )、73 % (11/15 )、96% (5 4/5 6)。前列腺癌组织中Clusterin表达水平明显高于前列腺正常 (t=8 82 ,P <0 0 1)及增生 (t =7 63 ,P <0 0 1)组织 ,且在癌组织中与肿瘤病理分级 (r =0 64 9,P <0 0 1)、临床分期 (r=0 60 9,P <0 0 1)呈正相关。