Estrogen receptor beta inactivates critical genes, arrests cancer cell growth

Bionovo, Inc. (Nasdaq: BNVI) today announced the publication of a study demonstrating that ERb causes cancer cell growth arrest by inactivating critical genes and enzymes responsible for cell growth. These results provide evidence that drugs that stimulate the production of or activate ERb are potential new therapies to prevent breast cancer.  

The study is entitled "Estrogen receptor beta causes a G2 cell cycle arrest by inhibiting CDK1 activity through the regulation of cyclin B1, GADD45A, and BTG2", in the journal Breast Cancer Research and Treatment.

"Recently the selective estrogens receptor modulators (SERMs), raloxifene and tamoxifen have been shown to prevent breast cancer in women who have known risk factors for the disease by blocking the effects of estrogen receptor alpha in breast tissue," said Dale Leitman, M.D., Ph.D., from the Department of Nutritional Science and Toxicology, University of California, Berkeley and Bionovo's Scientific Advisory Board. "Unfortunately, the SERMs can activate ERa in other tissues and can cause serious side-effects, such as endometrial cancer, so most women are unwilling to use them. For over a decade, we have been exploring alternative strategies to prevent breast cancer with novel compounds that only act on the estrogen receptor beta (ERb). In this study, we demonstrated that ERb halts the growth of breast cancer cells by regulating several key genes that control the growth of cancer cells, including cyclin B1, GADD45A and BTG2. These results provide sound scientific evidence to support the further development of ERb agonists as therapies to prevent and treat breast cancer."

"The reproductive hormone estrogen and the receptors that mediate its activity in cells are critical for maintaining women's health and treating diseases common in women," said Isaac Cohen, O.M.D., Chairman and CEO of Bionovo, Inc. "When estrogen is used as a drug it results in some beneficial effects, yet these positive effects are coupled with the potential for many serious side effects. By understanding how ERb prevents the growth of cancer cells, we can create more specific targeted drugs that activate this path. Bionovo has been dedicated to identify new drugs that target ERb, and established a large pipeline of compounds that interact selectively with ERb. We plan to test these drugs in clinical trials for breast cancer prevention, which still takes the lives of 45,000 women every year."