氧化固醇硫酸化-巨噬细胞胆固醇代谢新的调控点

项目名称： 氧化固醇硫酸化-巨噬细胞胆固醇代谢新的调控点

项目编号： No.30800547

项目类型： 青年科学基金项目

立项/批准年度： 2009

项目学科： 化学工业

项目作者： 李晓波

作者单位： 复旦大学

项目金额： 20万元

中文摘要： 肝癌细胞中氧化固醇硫酸基转移酶SULT2B1的表达水平较正常肝细胞高，过表达SULT2B1促进细胞增殖，干扰SULT2B1表达抑制细胞增殖，抑制裸鼠皮下移植瘤生长，诱导细胞凋亡，促使细胞周期阻滞在G2/M期。干扰SULT2B1表达上调FAS、p-JNK，并抑制bcl-2、c-myc和cyclin B表达，还可导致hepa-16细胞迁移能力下降，促血管新生能力受阻。本研究还发现肝细胞中SULT2B1mRNA水平可以被促炎介质如LPS、TNF-alpha和棕榈酸等上调。雌激素硫酸化参与了靶器官组织雌激素的灭活。本研究发现雌激素敏感性肿瘤，乳腺癌和子宫内膜癌中癌和癌旁组织的雌激素硫酸基转移酶SULT1E1和PAPSS表达水平有显著差异。过表达SULT1E1和PAPSS1可以通过阻滞细胞周期和诱导细胞凋亡的途径而抑制雌激素受体阳性乳腺癌细胞生长。SULT1E1在原代脐静脉内皮细胞中表达丰富。SULT1E1干扰之后可上调血管内皮细胞中抗炎因子和脂质代谢因子的表达，下调促炎因子的表达；而核受体PPARγ21017;能逆转SULT1E1的调节作用，而且上述作用可能并不依赖于雌激素的存在。

中文关键词： 硫酸化；SULT2B1；SULT1E1；氧化固醇；雌激素

英文摘要： SULT2B1 is responsible for the oxysterol sulfation by providing catalyzing enzyme. The present study investigated the role of SULT2B1 in the carcinogenesis and development of hepatocellular carcinoma. The results indicated that the expression of SULT2B1 in hepatocarcinomal cells was higher than that of normal cells. Overexpression of SULT2B1 by Ad-SULT2B1 promoted the cells growth, while SULT2B1-RNAi-LV apparently inhibited growth of the Hepa1-6 cells and suppressed tumorigenesis in subcutaneous xenograft model. Knockdown of SULT2B1 induced cell apoptosis and arrested cell cycles in G2/M by upregulation of FAS, p-JNK，and downregulation of bcl-2、c-myc and cyclin B1. Knockdown of SULT2B1 also inhibited the hepa1-6 cell migration and invasion capability and its TCM on bEND.3 cell proliferation in vitro. We also observed that the mRNA levels of SULT2B1 could be upregulated by proinflamatory factors, such as LPS，TNF-alpha and palmitic acid. SULT1E1 and PAPSS (PAPSS1 and PAPSS2) are responsible for the estrogen sulfation by providing catalyzing enzyme and universal sulfate donor. By tissue array analysis and the assessment of clinical samples，the estrogen sulfation enzymes were comparatively higher in the tumorous tissues than their adjacent normal tissues. SULT1E1 overexpression inhibited the tumorigenesis in subcutaneous xenograft model. By CCK-8 assay and flow cytometry assay, overexpression of SULT1E1 and PAPSS1 by adenovirus blocked the estrogen pro-proliferating effect and promoted cell apoptosis induced by H2O2 in MCF-7 cells. By Real-time RT-PCR and Western-blot assays, overexpression of SULT1E1 and PAPSS1 suppressed cell growth and triggered apoptosis by downregulating the levels of c-myc, cyclin D1 and bcl-2, meanwhile, upregulating bax expression. Overexpression of SULT1E1 and PAPSS1 retarded MCF-7 cells growth in vivo and in vitro by arresting cell cycles and inducing apoptosis. Thus, targeting SULT1E1 and PAPSS expressions might be an important approach for estrogen-dependent cancers. SULT1E1 expression was high in human umbilical vein endothelial cells (HUVEC) . Expressions of pro-inflammation genes (TNF-α#65292;IL-6，Fas ) and lipid metabolism related genes (ApoB, CD36,ABCA1 and FAS)were downregulated, anti-inflammation gene IL-4 was upregulated significantly by SUTL1E1 RNAsi; Meanwhile ,transcriptional factor PPARγas increased by interference of SULT1E1 ; PPARγNAsi reversed SULT1E1 regulation on target genes by interference of SULT1E1 and PPARγxpression simultaneously; SULT1E1 regulations were still exist in the absence of exogenous estrogen with charcoal stripped serums.

英文关键词： sulfation; SULT2B1; SULT1E1; oxysterol; estrogen