Expression of estrogen receptor beta in colon cancer progression.

Colon cancer is the most frequent neoplasia of the intestine. This pathology is the third highest cause of death from cancer with 430,000 deaths globally per year. Estrogen has also been implicated in the development and progression of colon cancer. Also sex-specific differences have been suggested to be involved in the process. Previous studies have shown the estrogen beta receptor to be the dominant receptor type in normal colonic tissue and its down-regulation along with the progression of colorectal cancer. The presence of estrogen receptors and products of estrogen-related genes in the colon suggests that estrogens have direct effects on the colonic tissue. However, the specific effect of estrogens on a normal colon and the role in the colon carcinogenesis are far from clear. The aim of this study is to analyze by real-time polymerase chain reaction, the relative quantitative expression of the estrogen receptors beta, beta1, beta2, and beta5 in colon adenocarcinomas and to compare this expression with the respective in normal tissues. Moreover, we evaluate a possible correlation between estrogen's receptor expressions and disease stages. Normal tissues show estrogen receptor beta expression greater than pathologic tissues and the estrogen receptor beta result as most expressed in the lower disease stages.