Down-regulation of the metastatic function of β- catenin by Estrogen and Estrogen receptor-a in HA22T Hepatocellular carcinoma Cell line

• Main Authors: Hwai-lee Wang, 王惠勵
• Other Authors: Chih-yang Huang
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/82986175217837481867

碩士 === 國立中正大學 === 分子生物研究所 === 95 === Reports indicate the incidence of hepatocellular carcinoma (HCC)is higher in men than in women. Our previous data also show that estrogen and estrogen receptor a(ERa significantly suppress Hep3B and LoVocolon cancer cell genesis. We even found that β-catenin level is significantlyhigher and translocation more into nucleus in HCC tumor areas , andappeared more significantly at the late stages of HCC. After we apply theantisense oligonucleotides to knock down β-catenin gene in HA22T HCC cell line, resulting in the inhibition of cell migration and invasion activities.In order to further confirm estrogen and ER-a mediates through the suppression of β-catenin expression to reduce HCC cell motility.We co-transfect pCMV-β-catenin and ER-a into HA22T cell ,and determined the variationof cell motility by wound healing、invasion and migration assay . Results show that estrogen and /or ER-a inhibit β-catenin gene expression andrepress HA22T cell motility. Similarly data were observed in the ER-a stable clone system.Moreover,we discovered the protein-protein interaction between ER-a and β- catenin by immunostain, co-immunoprecipitationassay and western blotting ,which lead to the nucleus export effect of β- catenin and the overexpression of β-catenin undivided E3 ligase,βTrCP,promote β-catenin protein ubiquitination and degradation.At the same time,EMSA and Chip assay were applied to identify the ER-a mediates through the binding of SP-1 site on β-catenin promoter to repress β- catenin gene expression.