摘要
背景与目的:环氧化二十碳三烯甘油酸(EETs)由细胞色素P450(CYP)表氧化酶从花生四烯酸合成而来,研究发现,CYP表氧化酶在癌组织中明显高表达,而癌旁正常组织中几乎不表达,并且证实CYP表氧化酶及其代谢产物可能与肿瘤的发生、发展存在密切关系。本研究目的在于研究EETs对肿瘤细胞的促增殖作用及其相关的机制。方法:分别以不同浓度的EETs(8,9-EET、11,12-EET和14,15-EET)作用Tca-8113、A549、Ncl-H446和HepG2肿瘤细胞12、24、48h和72h后,MTT法检测细胞增殖情况。流式细胞仪检测外源性EETs对Tca-8113细胞周期的影响。用选择性抑制剂来阻断细胞增殖的MAPK、PI3K/Akt和PKC细胞信号转导通路,并用Westernblot法检测PI3K/Akt和ERK1/2总蛋白水平和磷酸化水平。结果:与对照组和溶媒组比较,EETs可明显促进肿瘤细胞的生长,并呈明显的浓度依赖性和时间依赖性(P<0.01)。流式细胞仪分析显示,EETs处理后的肿瘤细胞在S-G2/M期的细胞数增多。11,12-EET处理Tca-8113细胞后S期和G2/M期细胞[(49.7±7.5)%vs.(21.0±5.3)%]较对照组明显增多(17.2±9.7)%vs.(4.9±7.3)%],差异有统计学意义(P<0.01)。用EETs培养后肿瘤细胞的MAPK和Akt磷酸化水平显著增加,而且其抑制剂能够阻断EETs诱导的细胞增殖作用。结论:EETs具有促进肿瘤细胞增殖的作用,MAPK和PI3K/Akt细胞转导通路在此过程中起重要作用。
BACKGROUND ＆ OBJECTIVE= Epoxyeicosatrienoic acids （EETs） are generated from arachidomic acid by cytochrome P450 （CYP）. Previous studies revealed very strong and selective expression of CYP expoxygenase in human cancer tissues, but almost none in adjacent normal tissues. This study was to investigate the promotive effect of EETs on proliferation of tumor cells and the possible mechanisms. METHODS= Four tumor cell lines, Tca-8113, A549, NcI-H446 and HepG2, were treated with different concentrations of EETs （8,9-EET, 11,12-EET and 14,15-EET） for 12, 24, 48 and 72 h, respectively. Cell proliferation was measured using the MTT assay. The effect of exogenous EETs on cell cycle of Tca-8113 cells was assessed by flow cytometry. Signal transduction inhibitors of P13K （LY294002）, MAPKK （PD98059）, MAPK （apigenin） and PKC （H7） were used to block EETs-induced cell proliferation. Expressions of the total protein and phosphorylated ERK1/2 and Akt were determined by Western blot. RESULTS. EETs promoted proliferation of tumor cells compared with the control and vehicle group in a dose- and time-dependent manner （P〈0.01）. Incubation of tumor cells with EETs markedly increased the cell number at S/ G2-M phase. The percentages of Tca-8113 cells at S and G2-M phases were （49.7±7.5%） vs. （17.2±9.7%） （P〈0.01） and （21.0±5.3%） vs. （4.9±7.3%）, respectively（P〈0.01） with and without the treatment of 11,12-EET. EETs incubation significantly enhanced phosphorylation of MARK as well as PI3K/ Akt in tumor cells. LY294002, PD98059, apigenine and H7 reduced the stimulative effect of EETs on cell proliferation. CONLUSlON： EETs possess the promotive effect on proliferation of tumor cells via activation of MAPK and PI3K/Akt signal pathways.
出处
《癌症》
SCIE
CAS
CSCD
北大核心
2008年第11期1130-1136,共7页
Chinese Journal of Cancer
基金
国家自然科学基金项目(No.30340067)
科技部国际合作项目(No.2005DFA30880)~~
