水通道蛋白3参与缺氧介导的结直肠癌化疗耐药的机制研究

Mechanism of AQP3 in the chemoresistance of colorectal carcinoma mediated by hypoxic condition

目的:探讨水通道蛋白3(aquaporin 3,AQP3)在缺氧介导结直肠癌(colorectal carcinoma,CRC)化疗耐药中的作用及意义。方法:通过实时荧光定量PCR和Western blot实验检测缺氧条件下结直肠癌HCT116、HT29细胞中AQP3表达的变化;通过CCK-8实验检测在氟尿嘧啶(5-fluorouracil,5-Fu)作用下,缺氧对HCT116细胞化疗敏感性的影响;通过CCK-8和平板克隆形成实验检测AQP3对缺氧条件下HCT116细胞化疗敏感性的影响。结果:在缺氧条件下,HCT116、HT29细胞中AQP3 m RNA以及蛋白表达水平均显著上调;抑制缺氧诱导因子-1α(hypoxia inducible factor,HIF-1α)表达,缺氧条件下HCT116细胞中AQP3mRNA、蛋白表达水平均未显著增加。在缺氧条件下,HCT116细胞对5-Fu的化疗敏感性低于常氧条件;抑制AQP3表达,HCT116细胞对5-Fu化疗敏感性增加。平板克隆形成实验也证明了抑制AQP3表达可增加HCT116细胞在缺氧条件下的化疗敏感性。结论:在缺氧条件下,HIF-1α上调AQP3表达,继而导致结直肠癌细胞对5-Fu耐药。

Objective:This study aims to investigate the role of aquaporin 3(AQP3)in the chemoresistance of colorectal carcinoma mediated by hypoxia. Methods:Real-time quantitative PCR and Western blot were performed to detect the expression of AQP3 under hypoxic condition in colorectal carcinoma HCT116 cells and HT29 cells. CCK-8 was used to detect the influence of hypoxia on the sensitivity of HCT116 cells to 5-fluorouracil(5-Fu)under hypoxic condition. CCK-8 and colony formation assay were also used to detect the effect of AQP3 on the sensitivity of HCT116 cells to 5-Fu under hypoxic condition. Results:Under hypoxic condition,the expression levels of AQP3 mRNA and protein were significantly up-regulated in both HCT116 and HT29 cells. After hypoxia inducible factor(HIF-1α)was inhibited,and the expression levels of AQP3 mRNA and protein in HCT116 cells under hypoxic condition were not significantly increased. Under hypoxic condition,the sensitivity of HCT116 cells to 5-Fu was lower than that in normal oxygen condition,which was reversed by inhibiting AQP3. Colony formation assay also demonstrated that the effect of 5-Fu on the proliferation ability of HCT116 cells was smaller under hypoxic condition,which was reversed by inhibiting AQP3. Conclusion:Under hypoxic condition,colorectal carcinoma up-regulated AQP3 expression by HIF-1α,which lead to 5-Fu chemoresistance.