New York, Dec 1 (IANS): A human immunodeficiency virus (HIV) drug that targets a specific protein involved in the immune system can also block the spread of prostate cancer cells to bones, says a new research.

Although prostate cancer can be successfully treated in many men but if the disease spreads to the bone, it is eventually lethal.

"The drug is already approved by the FDA (US Food and Drug Administration) for HIV treatment. We may be able to test soon whether this drug can block metastasis in patients with prostate cancer," said senior study author Richard Pestell from the Thomas Jefferson University in the US.

The research was complicated by the fact that there was no immune-competent mouse model of prostate cancer that reliably developed bone and brain metastasis.

So, the researchers developed a prostate cancer cell line that regularly caused bone metastasis in immune-competent mouse models.

The researchers then administered the HIV drug Maraviroc to the prostate cancer mouse model.

In comparison to control animals, Maraviroc dramatically reduced the overall metastatic load by 60 percent in the bone, brain and other organs.

Finally, in order to determine whether a similar mechanism might be at play in human prostate cancer, the researchers mined the genomic data of patients with prostate cancer and found that the protein called CCR5 was more highly expressed in prostate cancer tissue compared with normal tissue.

The study appeared in the journal Cancer Research.