PPARα/COX-2/PGE_2通路在人结肠癌耐药细胞中的作用研究

Role of PPARα/COX-2/PGE_2 pathway in human drug resistant colon cancer cell line

目的初步检测PPARα对COX-2蛋白表达和酶活性的影响,推测PPARα/COX-2/PGE2通路在人结肠癌耐药细胞中的可能作用。方法 Real-Time PCR和Western blot检测SW1116细胞、SW1116/HCPT细胞,以及下调PPARα表达后SW1116细胞中COX-2的表达差异;ELISA检测WY-14643分别干预SW1116细胞,SW1116/HCPT细胞,以及下调PPARα表达后各组细胞培养上清中PGE2含量;流式细胞术检测不同浓度PGE2对细胞周期的影响。结果 COX-2在耐药细胞中表达明显下调。PPARα表达下调抑制COX-2表达。PPARα激动剂WY-14643促进细胞释放PGE2[250μM:(0.7851±0.0203)ng/m L vs(0.2443±0.01228)ng/m L,P=0.000;100μM:(0.5483±0.0614)ng/m L vs(0.2443±0.01228)ng/m L,P=0.0083];PGE2降低细胞周期G1期比例,升高S期比例,PI由对照组的(32.2±2.13)%,上升到(42.2±3.14)%、(52.1±2.43)%,P=0.0123。结论人结肠癌耐药细胞中COX-2表达显著下调;PPARα有促进COX-2蛋白表达和酶活性的作用。

Objective To explore the regulation of PPARα to COX-2 protein expression and COX-2 enzyme activity, and to find out the role of PPARα/COX-2/PGE2 pathway in drug resistance colorectal cancer cells. Methods The expressions of COX-2 were measured by Realtime PCR and Western blot in SWlll6 cells, SW1116/HCPT cells and SW1116 cells transfected with siRNA vectors for silencing PPARα; PGE2 concentration in culture supernatants was detected by ELISA in SWlll6 cells and SW1116/HCPT cells treated with PPARα agonist WY-14643, SW116 cells and SWlll6/HCPT cells transfected with siRNA vectors for silencing PPARoq cell cycles of SW1116/HCPT cells treated with PGE2 were assessed by flow cytometry. Resuits Protein and mRNA expressions of COX-2 were much lower in SW1116/HCPT cells and SW1116 cells transfected with siRNA vectors for silencing PPARα than in SW1116 cells. PGE2 concentrations in cells culture supernatants of SW1116/HCPT cells were elevated after treatment with WY-14643 [100 μM： （0.5483 ± 0.0614）ng/mL; 250 μM： （0.7851 ±0.0203）ng/mL]; proliferation index were elevated in SW1116/HCPT cells with PGFα [104 tool/L： （42.2± 3.14）; 10-7 mol/L： （52.1 ±2.43）%; con： （32.2± 2.13）%]. Conclusions The expression of COX-2 were much lower in SWlll6/HCPT cells than in SWl116 cells. PPARα promoted the protein expression and enzyme activity of COX-2.