重组RA-538及反义c-myc腺病毒对人胃癌、食管癌和bcl-2高表达细胞系的作用及其分子机制的体内外研究

本课题研究RA53 8、反义c ymc重组腺病毒对人胃癌 (SGC790 1 )、食管癌(EC1 0 9、EC871 2 )、正常人胚肺 2BS ( 2BS)及bcl 2高表达细胞系的体内外生物学作用及其分子机制。结果显示Ad RA53 8及Ad ASc myc对SGC790 1细胞体内外均具有明显的生长抑制及凋亡诱导作用 ,并能抑制其c myc、bcl 2、cyclinD1基因的表达及刺激bax基因的表达。对EC1 0 9、EC871 2、2BS及bcl 2基因高表达细胞系均无明显的生长抑制及凋亡诱导作用 ,对这些细胞系中c myc、bcl 2基因的表达均无调节作用。结果表明Ad RA53 8、Ad ASc myc对胃癌细胞具有显著的体内外生长抑制及凋亡诱导作用 ,其作用是c myc、bcl 2、bax、cyclinD1等一系列基因表达变化及其相互作用的结果。对食管癌、2BS及bcl 2高表达细胞系则无类似作用。     

三氧化二砷诱导人宫颈癌HeLa细胞凋亡及Bcl-2保护作用的机制研究

探讨三氧化二砷 (As₂ O₃)对人宫颈癌HeLa细胞的生物学效应和Bcl -2的高表达对这一效应的影响 .通过MTT ,克隆形成实验 ,形态观察 ,流式细胞仪 ,DNA凝胶电泳 ,细胞凋亡原位检测 (TUNEL) ,RT PCR ,Northernblot,Westernblot等方法发现As₂ O₃明显降低HeLa细胞存活率 ,并诱导其凋亡和细胞周期G2 /M期阻滞 ,分析显示As2 O3可能主要通过抑制c -myc基因和病毒致瘤基因的表达来诱导HeLa细胞凋亡 .Bcl -2的高表达也可能正是通过降低As₂ O₃对G2 /M期阻滞 ,逆转As₂ O₃对c -myc基因的降调节 ,减轻As₂ O₃对病毒致瘤基因的表达抑制作用 ,来部分阻止这种凋亡的发生 .我们还发现As₂ O₃能引起Bc1-2高表达HeLa细胞G2 /M期的弱阻滞 ,降调Bcl -2的表达以及略微抑制病毒致瘤基因的表达 ,这可能是As₂ O₃仍能诱导Bcl -2高表达HeLa细胞凋亡的原因 .     

Mechanisms of arsenic trioxide induced apoptosis of human cervical cancer HeLa cells and protection by Bcl-2

It was recently reported that arsenic trioxide (As_2O_3) can induce complete remission in patients with acute promyelocytic leukemia (APL). In this present article, the biological effect of As_2O_3 on human cervical cancer HeLa cells and HeLa cells overexpressing Bcl-2 is studied. By MTT and colony forming ability assays, morphology alteration, flow cytometric analysis, DNA gel electrephoresis and in situ cell death detection (TUNEL), it was found that As_2O_3 inhibited the growth of HeLa cells and induced G2/M arrest and apoptosis of the cells. RT-PCR, Northern blot, Western blot analysis revealed that As_2O_3 induced HeLa cell apoptosis possibly via decreasing the expression of c-myc and viral genes. HeLa cells overexpressing Bcl-2 partly resist As_2O_3 induced apoptosis, which might be relative to preventing the cells from As_2O_3 caused G2/M block, downregulation of c-myc gene expression and inhibition of viral gene expression was also noted, However, it was found that As_2O_3 at a high concentratio