PIASy在结直肠癌中的异常表达及其对结直肠癌细胞凋亡和周期的影响

PIASy expresses abnormally in human colorectal cancer tissues and affects the apoptosis and cycle of colorectal cancer cells

目的:探讨PIASy(protein inhibitor of activated STAT4)在人结直肠癌(colorectal cancer,CRC)组织中的表达情况及其对人结直肠癌细胞SW480凋亡及细胞周期的影响。方法:选取25例CRC组织及其对应癌旁组织作为研究对象,采用荧光定量PCR方法检测PIASy在CRC及正常癌旁组织中的相对表达水平;运用细胞转染技术使PIASy在SW480中过表达;通过流式细胞技术检测并对比转染前后细胞凋亡及细胞周期的变化情况。结果:在25例CRC及其相对应的癌旁正常组织中,PIASy阳性的癌旁组织为9例(阳性率36%),PIASy阳性的肿瘤组织为2例(阳性率8%),2组差异具有统计学意义(P=0.041);且癌旁组织中PIASy的相对表达量明显高于对应的肿瘤组织(CRC04:P=0.016;CRC18:P=0.001);PIASy过表达的SW480细胞凋亡水平明显升高(早期凋亡:P=0.000;晚期凋亡:P=0.014),且出现S期细胞的比例明显升高(P=0.000)。结论:PIASy在CRC中存在缺失表达或低表达;外源性PIASy的过表达可诱导SW480细胞发生凋亡,并促使细胞周期出现S期阻滞。PIASy可能在CRC的发生发展中扮演着较为重要的作用。

Objective：To investigate the expression of PIASy in human colorectal cancer（CRC）tissues and adjacent tissues;to detect the effects of PIASy on colorectal cancer cells apoptosis and cycle. Methods：Totally 25 cases of CRC tissues and corresponding adjacent tissues were selected as research subjects. The relative expression level of PIASy in CRC tissues and adjacent tissues was investigated by Q-PCR;exogenous PIASy was over-expressed by cell transfection with Lipofectamine 2000;the cell apoptosis and cycle of SW480 cell line was detected by flow cytometry. Results：In 25 cases of CRC tissues and adjacent tissues,there were 9 cases（positive rate of 36%） of PIASy positive adjacent tissues,2 cases（positive rate of 8%） of PIASy positive cancer tissues（P =0.041）,and the relative expression level of PIASy in adjacent tissues was significantly higher than that in cancer tissues（CRC04：P=0.016;CRC18：P=0.001）;over expression of exogenous PIASy induced SW480 cell early apoptosis（P =0.000）,late apoptosis（P =0.014） and prompted the S phase arrest in cell cycle（P=0.000）. Conclusion：PIASy is loss of expression or low expression in colorectal CRC;over-expression of exogenous PIASy in SW480 cells can induce cell apoptosis and promote cell cycle S phase arrest,suggesting PIASy may play an important role in the occurrence and development of CRC.