siRNA沉默RIP1可增强奥沙利铂诱导口腔癌细胞的凋亡

Small interfering RNA-mediated RIP1 knockdown enhances L-OHP sensitivity of human oral squamous carcinoma cells

目的探讨siRNA沉默受体相互作用蛋白激酶1(RIP1)增强奥沙利铂(L-OHP)诱导口腔癌细胞凋亡的作用,以期为口腔癌的临床治疗提供新的靶点。方法 MTT法检测不同浓度(0、0.25、0.5、1、2、4μmol/L)L-OHP对口腔癌细胞KB的增殖抑制作用;Western blotting检测L-OHP(1μmol/L)处理口腔癌细胞KB不同时间(0、6、16、24 h)RIP1的表达及siRNA转染沉默RIP1口腔癌细胞KB中RIP1的表达;PI/Annexin V双染法检测L-OHP(1μmol/L)对siRNA转染沉默RIP1后口腔癌细胞KB凋亡的影响,同时将未转染和转染空质粒口腔癌细胞KB作为空白和阴性对照。结果 1μmol/L L-OHP作用于口腔癌细胞KB 24、48、72 h细胞存活率分别为67.66%、55.17%和41.34%,但24 h细胞凋亡率仅为9.6%。用L-OHP刺激口腔癌细胞KB RIP1的表达随时间延长不断上升,而siRNA转染沉默RIP1后,RIP1表达明显下降。siRNA转染沉默RIP1后,细胞的凋亡率为9.4%,沉默RIP1并合用L-OHP进行刺激,细胞的凋亡率为29.1%,明显高于单用L-OHP组。结论抑制RIP1的表达可以增强奥沙利铂诱导口腔癌细胞的凋亡,为口腔癌的临床治疗提供了新的靶点。

Objective To investigate the effect of small interfering RNA- mediated receptor- interacting protein kinase 1 （RIP1） knockdown on the sensitivity of human oral squamous carcinoma cells to to oxaliplatin （L- OHP）- induced apoptosis and explore a new target for clinical treatment of oral squamous carcinoma. Methods The viability of human oral squamous carcinoma cell line KB exposed to different concentrations （0, 0.25, 0.5, 1, 2, 4 μmol/L） of L-OHP were detected by MTT assay. PI/Annexin V staining was used to observe cell apoptosis in naive KB cells, cell and transfected with pSH1Si-RIP1 or with the empty plasmid. Western blotting was used to detect RIP1 expression in KB cells exposed to L- OHP and in cells transfected with pSH1Si-RIP1. Results Exposure to L-OHP （1μmol/L） for 24, 48, 72 h resulted in KB cell survival rates of 67.66%, 55.17%, and 41.34%, respectively, but the cell apoptosis rate was only 9.6% following a 24-h exposure. KB cells transfected with pSH1SiRIP1 showed an apoptotic rate of 9.4%, which increased to 29.1% following L-OHP exposure. RIP1 expression was first upregulated and then down-regulated in KB cells treated with L-OHP, and was significantly reduced after cell transfection with pSH1Si- RIP1. Conclusion Suppression of RIP1 expression increases the apoptotic rate of human oral squamous carcinoma cells, suggesting the potential of RIP1 as a new candidate target for clinical treatment of oral squamous carcinoma.