Celebrex-Lipitor combo may fight prostate cancer
By Deena Beasley
SAN DIEGO (Reuters) - The combination of anti-inflammatory and cholesterol-lowering drugs may be able to stop the progression of prostate cancer, according to new research so far carried out only in mice.
"The two drugs work through different mechanisms of action, but there is a synergistic effect that inhibits the growth of prostate cancer cells," said Xi Cheng, assistant research professor at Rutgers, the State University of New Jersey, who conducted the study.
His team administered a combination of Celebrex, a non-steroidal anti-inflammatory drug used to treat arthritis and other pain, and Lipitor, a cholesterol lowering statin, to cultured mice tumors in order to measure the transition of early prostate cancer to its more aggressive and potentially fatal stage.
Both drugs are sold by Pfizer Inc, but the company played no role in the National Institutes of Health-funded study, Zheng said.
The researcher said both drugs have been shown in earlier studies to have some impact on cancer growth when used alone.
The Rutgers team found that the combination of low doses of Lipitor and Celebrex had a more potent impact on tumor growth than a higher dose of either agent when used separately.
Prostate cancer is the second-leading cause of cancer death in men in the United States, with more than a quarter-million new cases appearing each year, according to the American Cancer Society.
In the early stage of the disease, prostate cancer cells depend on androgen hormones, such as testosterone, to grow. Treatment involves either decreasing the production of the hormone or blocking its action.
"Anti-androgen therapy slows the prostate cancer but eventually the cancer becomes androgen-independent, the therapy becomes ineffective and the cancer cells become more aggressive," said Zheng.
"Treatments available for the later stage cancers are not very good," Allan Conney, director of cancer research at Rutgers, said in a statement. "Oncologists employ classical chemotherapy drugs which are very toxic and don't work all that well."
The objective of the Rutgers study was to indefinitely delay the transition to androgen-independence, prolonging the time during which the cancer would be responsive to low-toxicity, anti-hormone therapy.
Zheng said it appears that a cell signaling pathway for tumor cell growth is inhibited by the combination of the two compounds.
He said human clinical trials are being planned.
(Reported by Deena Beasley; Editing by Brian Moss)