• Hai-ping Jiang, Rong-yue Teng, Qi Wang, Xing Zhang, Hao-hao Wang, Jiang Cao, and Li-song Teng.
• Department of Oncological Surgery, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.
• Chinese Med J Peking. 2008 Jun 5; 121 (11): 1025-31.

BackgroundEstrogen is involved in suppression of colon cancer development and exerts its function via estrogen receptors alpha and beta (ERalpha, ERbeta). The recently identified ERalpha46 resulted from exon 1-deletion from the 66-kDa full length form of ERalpha66 is devoid of the transactivation domain AF-1, whose function remains largely unknown.MethodsIn this study, we compared the expression of ERalpha46 mRNA in 32 normal colorectal tissues and their matched colorectal cancer tissues by real-time quantitative polymerase chain reaction (PCR). Human colon adenocarcinoma cell HT-29, that has low endogenous expression of ERalpha46, was transfected with ERalpha46-expression vector; methyl thiazolyl tetrazolium (MTT) assay, flow cytometry, DNA fragmentation and TUNEL staining were used to evaluate the proliferation and apoptosis status of the cells in the presence of 17beta-oestradiol.ResultsHigher ERalpha46 mRNA levels were observed in normal colorectal tissues than in the corresponding cancer tissues. ERalpha46-transfected cells showed a significantly decreased growth rate than control cells and an accumulation of cells in the G(0/1) phase and a reduced proportion of cells in G(2)/M phase after exposed to 10(-8) mol/L 17beta-oestradiol. There were also more positive TUNEL stained cells in ERalpha46-transfected cells than the control cells in the presence of 17beta-oestradiol (P < 0.05).ConclusionsThese data suggest that ERalpha46 may be involved in the development and/or progression of colorectal cancer via mediating growth inhibition and apoptosis of cancer cells in the presence of 17beta-oestradiol.

17 keywords...

hide…