Vit. D

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Vitamin D antimetastasis mechanism reported

The January 2006 issue of the journal Carcinogenesis reported the findings of researchers at the University of Rochester Medical Center that vitamin D helps prevent the spread of prostate cancer cells by limiting the activity of two enzymes. Prior research has shown that vitamin D suppresses cancer progression, but its mechanisms were unclear. "We wanted to know the targets of vitamin D so we would know which patients would respond better," explained lead researcher and University of Rochester assistant professor of Urology Yi-Fen Lee, PhD.

Dr Lee and colleagues studied the effect of 1,25-hydroxyvitamin D3, the active form of vitamin D in the body, on three different prostate cancer cell lines. They examined three groups of proteases (enzymes that break down protein) involved in tumor invasion: the matrix metalloproteinases, the plasminogen activators, and the cathepsins. They found that treatment with vitamin D decreased the activity of matrix metalloproteinase-9 and the cathepsins, but not the plasminogen activators. Simultaneously, tissue inhibitors of metalloproteinase-1 (TIMP-1) and cathepsin inhibitors were found to have an increase in their activity.

The finding will prove particularly useful for individuals who have high levels of matrix metalloproteinase-9 and cathepsin activity. "Each individual is different so the therapy could be custom made for each person," Dr Lee remarked.

Dr Lee is currently investigating whether pharmaceutical agents or other vitamins, such as vitamin E, could enhance the anticancer benefits of vitamin D. She stated, "The best way to get vitamin D is to drink milk, get modest exposure to the sun, and take a vitamin pill to enrich the vitamin D, which might prevent cancer."

Protocol

Prostate cancer adjuvant therapy

Genistein has been proposed as an effective agent to prevent the expression of metastatic capacity in hormone dependent cancers. In a cell-culture system, genistein appeared to be cytotoxic and inhibitory of PC cell proliferation (Geller et al., Prostate, 1998). Genistein and soy products therefore play a potential major role in established PC. Cancer cells use the enzyme tyrosine kinase as a growth factor. Soy genistein is a potent inhibitor of tyrosine kinase activity. The effects of protein kinase inhibitors on human prostate cell growth have been extensively investigated.