中文摘要：

目的:探讨KLF8(Kruppel-like factor 8)在缺氧诱导胃癌细胞多药耐药表型中的作用。方法:利用Western blot和实时定量PCR的方法检测三株胃癌细胞系MKN28、MKN45、SGC7901在常氧及缺氧条件下KLF8的表达水平。Western blot和实时定量PCR检测胃癌耐药细胞系SGC7901/VCR、SGC7901/ADR和亲本细胞系SGC7901中KLF8的表达水平。构建KLF8正义表达载体及KLF8小干扰RNA的慢病毒载体,将其转染入实验细胞中,用Western blot和实时定量PCR的方法检测KLF8表达量的变化。MTT、Annexin V/PI染色法及阿霉素蓄积量与潴留实验检测KLF8在缺氧诱导胃癌细胞多药耐药表型中的作用。结果:缺氧可诱导胃癌细胞系MKN28、MKN45、SGC7901中KLF8的表达升高。与胃癌亲本细胞系相比,KLF8在胃癌耐药细胞系中的表达升高,并且在SGC7901/VCR细胞中表达升高的更为明显。外源性转染KLF8后可显著增加胃癌细胞中KLF8的表达量,KLF8小干扰RNA可有效降低常氧及缺氧条件下胃癌细胞中KLF8的表达。常氧条件下,外源性转染KLF8的正义表达载体可增加胃癌细胞对不同化疗药物的耐受性,降低化疗药物诱导的胃癌细胞凋亡指数,同时可增加细胞内阿霉素的泵出率。缺氧条件下,KLF8小干扰RNA能够逆转胃癌细胞中上述现象的发生。结论:初步实验结果发现了一个新的缺氧反应分子-KLF8。表型试验证实该分子在缺氧诱导胃癌多药耐药中发挥作用。

英文摘要：

Objective:To investigate the role of KLF8 involving the hypoxia -induced MDR.Methods:The KLF8 level was detected by Western blot and RT -PCR assay in gastric cancer cell lines MKN28,MKN45 and SGC7901 under normoxic and hypoxic conditions.KLF8 level was detected on the gastric cancer drug -resistant cell lines SGC7901 /VCR,SGC7901 /ADR and parental cell line SGC7901.Exogenous KLF8 and KLF8 -siRNA were transfect-ed into the experimental cells,and the KLF8 level was detected by Western blot and RT -PCR assays.MTT,Annexin V /PI,Adriamycin accumulation and retention assays were used to detect the function of KLF8 involving in the hypoxia-induced phenotype of MDR in gastric cancer cells.Results:Hypoxia could effectively increase the KLF8 expression in MKN28,MKN45 and SGC7901 gastric cancer cells.The levels of KLF8 in the drug -resistant cell lines were high-er than in the parental cell lines,especially in drug resistance cell lines.Exogenous KLF8 could increase the KLF8 level in gastric cancer cells,and the KLF8 -siRNA could reduce the KLF8 level effectively in gastric cancer cells in normoxia and hypoxia.In normoxia,exogenous KLF8 could increase the tolerance of gastric cancer cells in the chemo-therapy drugs,reduce hypoxia -induced apoptotic index and increase the adriamycin releasing rate.KLF8 -siRNA could reverse the phenomenon in gastric cancer cell under hypoxic condition.Conclusion:We firstly revealed that KLF -8 is a novel hypoxia response molecular in gastric cancer.Further study suggested that KLF8 participated in the hypoxia -induced MDR in gastric cancer cells.