Downregulation of survivin by siRNA diminishes radioresistance of pancreatic cancer cells
Downregulation of survivin by siRNA diminishes radioresistance of pancreatic cancer cells
复制标题
DOI：
10.1016/j.surg.2005.05.009
复制
发表时间：
2005-08-01
期刊：
影响因子：
3.8
通讯作者：
Imamura, M
中科院分区：
文献类型：
--
作者：
Kami, K;Doi, R;Imamura, M
背景Survivin是细胞凋亡抑制蛋白家族的成员，具有抑制细胞凋亡和调节细胞分裂的作用。存活素在大多数人类癌症中表达，包括胰腺癌。我们已经报道了它的表达与胰腺癌患者的较短生存期相关，因此调节该分子可能是对抗胰腺癌的新策略。在3个胰腺癌细胞系（AsPC-1，SUIT-2和Panc-1），生存素启动子活性测定荧光素酶报告基因分析，生存素信使RNA（mRNA）的表达进行了研究，通过定量逆转录-聚合酶链反应。还评估了辐射的剂量依赖性细胞毒性，同时评价了caspase-3活性和DNA片段化的诱导。此外，我们还观察了针对survivin基因的沉默或非沉默短干扰RNA（siRNA）表达质粒对放射抗性最强的细胞系AsPC-1细胞的影响。胰腺癌细胞系表达不同水平的生存素mRNA，与生存素启动子的转录活性相关。Survivin启动子活性和mRNA表达与肿瘤细胞放射敏感性相关。辐射显著增加了所有细胞系中Survivin启动子的活性和Survivin mRNA的表达。辐射诱导AsPC-1细胞caspase 3活性和DNA片段化显著增加。siRNA沉默AsPG-1细胞（AS-S细胞）后，与非沉默Scramble siRNA对AsPC-1细胞（AS-NS细胞）的影响相比，Survivin mRNA表达显著降低，caspase-3活性显著升高。AS-S细胞比AS-NS细胞放射敏感。与AS-NS细胞相比，辐射诱导AS-S细胞caspase-3活性升高，DNA断裂增多。Survivin可能作为放射抵抗因子之一发挥重要作用。通过siRNA下调survivin表达可降低胰腺癌细胞的放射抵抗性，因此抑制survivin与放射联合治疗可能对胰腺癌的治疗有一定的意义。
Background. Survivin is a member of the inhibitor of apoplosis protein family, which inhibits apoptosis and regulates cell division. Survivin is expressed by the majority of human cancers, including pancreatic adenocarcinoma. We have reported that its expression is correlated with shorter survival of pancreatic cancer patients, so regulation of this molecule could be a new strategy for fighting Pancreatic cancer.Methods. In 3 pancreatic cancer cell lines (AsPC-1, SUIT-2, and Panc-1), survivin promoter activity was determined by the luciferase reporter assay, and survivin messenger RNA (mRNA) expression was examined by quantitative reverse transcriptase-polymerase chain reaction. The dose-dependent cytotoxity of radiation was also assessed, while caspase-3 activity and induction of DNA fragmentation were evaluated. Furthermore, the effect of silencing or nonsilencing short interfering RNA (siRNA) expression plasmids directed against the survivin gene on AsPC-1 cells, the most radioresistant cell line, was evaluated.Results. Pancreatic cancer cell lines expressed varying levels of survivin mRNA in association with transcriptional activity of the survivin Promoter. Both survivin promoter activity and mRNA expression were correlated with tumor cell radiosensitivity. Radiation significantly increased survivin promoter activity and survivin mRNA expression in all cell lines. Radiation induced a significant increase in caspase 3 activity and DNA fragmentation in AsPC-1 cells. After silencing siRNA treatment of AsPG-1 cells (AS-S cells), there was a significant decrease in survivin mRNA expression and increase in caspase-3 activity, compared with the effect of nonsilencing scramble siRNA on AsPC-1 cells (AS-NS cells). AS-S cells were more radiosensitive than AS-NS cells. Radiation induced higher caspase-3 activity and more DNA fragmentation in AS-S cells, compared with AS-NS cells.Conclusions. Survivin may play an important role as 1 of the radioresistance factors. Downregulation of survivin by siRNA can diminish the radioresistance of pancreatic cancer cells, so combined therapy with survivin inhibition and radiation may be useful for the treatment of pancreatic cancer.