Metformin Shows Promise for Late-Stage Prostate Cancer.

In the January 23rd, 2015 issue [290(4):2024-33] of the Journal of Biological Chemistry, researchers published the finding of potential benefit for a combination of metformin and the gene inhibitor B12536 in late-stage prostate cancer.  Late-stage prostate cancer is commonly treated with androgen (hormone) deprivation therapy (ADT); however, the disease eventually becomes resistant to treatment.  Androgen deprivation can disturb the body’s metabolism, leading to insulin resistance that can stimulate unwanted androgen production.  Metformin, a drug commonly used to treat diabetes, helps reduce insulin resistance and has been associated with protection against specific cancers.  It is known that the gene poly-like kinase 1 (PLK1) can become over-expressed (overactive) during ADT and that its over-expression can also stimulate androgen synthesis, researchers tested the effects of administering the PLK1-inhibitor B12536 with low-dose metformin in prostate cancer cells.  The team found that the drugs worked synergistically to inhibit prostate cancer cell proliferation. The findings were confirmed in mice that received human prostate cell grafts. Further animal studies are underway with the eventual goal of initial human trials.