DISCOVERY IN BLADDER CANCER
Is the Androgen Receptor also responsible for bladder cancer development and progression?
Why is bladder cancer more than three times more common in men than in women? Maybe it has something to do with male hormones.
Drugs that block male hormones, or androgens, are used to treat advanced prostate cancer; recently, Hopkins investigators led by Hiroshi Miyamoto, M.D., Ph.D., looked at the effects of several of these drugs on bladder cancer in the laboratory.
Drugs that block male hormones stop bladder cancer growth in mice, and may also help cisplatin work better.
They found that the enzalutamide, flutamide and bicalutamide could “inhibit the proliferation, migration, and invasion of androgen receptor-positive bladder cancer cells, and stop tumor growth in mice,” says Miyamoto. This work will be published in the journal, Urologic Oncology. “Meanwhile, a significant amount of patients with bladder cancer fail to have successful responses to cisplatin-based systemic chemotherapy,” Miyamoto adds. “We assessed whether androgen receptor activity correlated with chemosensitivity.” They found that treatment with drugs that target the androgen receptor “significantly enhanced the cytotoxic activity of cisplatin.” This work is in press in the journal, Oncotarget.
Additionally, in lab studies of bladder cancer tissue specimens, the investigators found a strong link between androgen receptor expression and resistance to cisplatin-based chemotherapy. “These findings strongly suggest that a course of androgen deprivation therapy has the potential of being not only a therapeutic option, but also a means of chemosensitization, particularly in patients with androgen receptor-positive bladder cancer.”