ABSTRACT
<p><b>BACKGROUND</b>Estrogen 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.</p><p><b>METHODS</b>In 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.</p><p><b>RESULTS</b>Higher 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).</p><p><b>CONCLUSIONS</b>These 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.</p>
Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Apoptosis , Colorectal Neoplasms , Genetics , Pathology , Estradiol , Pharmacology , Estrogen Receptor alpha , Genetics , G1 Phase , HT29 Cells , MutationABSTRACT
Breast cancer is one of the leading causes of death in women today. Some of the patients are hereditary, with a large proportion characterized by mutation in BRCA1 and/or BRCA2 genes. In this review, we provide an overview of these two genes, focusing on their relationship with hereditary breast cancers. BRCA1/2 associated hereditary breast cancers have unique features that differ from the general breast cancers, including alterations in cellular molecules, pathological bases, biological behavior, and a different prevention strategy. But the outcome of BRCA1/2 associated hereditary breast cancers still remains controversial; further studies are needed to elucidate the nature of BRCA1/2 associated hereditary breast cancers.