Role of Vitamin D Receptor and PI3k Genes in Breast Cancer

Institution: University of California, San Francisco
Investigator(s): Bauke Ylstra, Ph.D. -
Award Cycle: 2001 (Cycle VII) Grant #: 7KB-0102 Award: $0
Award Type: New Investigator Awards
Research Priorities
Etiology and Prevention>Etiology: the role of environment and lifestyle

Initial Award Abstract (2001)
Any medicine that would reduce breast cancer risk, arrest tumor growth and spreading would be highly desirable. Vitamin D displays all of these features, however application has not been feasible, because the high doses required would raise calcium levels in the blood stream to lethal levels. In addition, sporadically researchers have shown cancer stimulatory effects of Vitamin D. Clearly a lack of knowledge hinders the development of Vitamin D-like drugs that target tumor growth but not calcium levels.

Breast tumor cells sense Vitamin D with a specific Vitamin D receptor (VDR). Unexpectedly, we found that in certain breast and lung cancers Vitamin D receptor gene expression is correlated with the expression of a second gene, PI3k. The PI3k gene is a central player amongst known cancer genes and detailed information is available about the mechanisms used by this gene to regulate cell and tumor growth. Therefore, further determination of the relationship between the two genes will explain many of the effects of Vitamin D during breast cancer progression, which is important for future drug design.

The main questions of this research in non-technical terms are: We will attempt to answer the questions posed above by doing the following: Clinical trials using Vitamin D or Vitamin D-like drugs alone or in combination with chemotherapy or other drugs have already been promising in breast cancer. Also, the known cancer genes regulated by PI3k are targets for anti-cancer drug design. A better understanding of an interaction between the two genes will enhance future therapeutic developments. In addition, the relation between the expression of the two genes may be used as important prognostic and diagnostic factors depending on the commonality of the correlation between the two genes.

Final Report (2001)
The PI resigned before work on the project began.