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HIV Drug Could Slowdown Prostate Cancer Spread

By Cathy Whims on December 1, 2014

HIV drugs trigger the receptor CCR5. This CCR5 is also one of the key that metastases prostate cancer. A new study suggested that blocking of CCR5 receptor will help in slowing down of Prostate cancer spread.

Of course, treatment for prostate can is successfully done in many men, but the cancer becomes lethal when it eventually metastasizes to bone.

This study was published online on December 1st in the journal Cancer Research. Richard Pestell, M.D., Ph.D., MBA, is the senior author of this study. He is also Director of the Sidney Kimmel Cancer Center at Thomas Jefferson. Xuanmao Jiao, Ph.D. is co-first author, and an instructor in the department of Cancer Biology at Jefferson.

According to this study, receptor CCR5 is best known for its role in HIV therapy. CCR5 may also have a role in driving the prostate cancer eventually metastasizing to bone.

Pestell said that as their study shows that metastasizing can be reduced dramatically at the pre-clinical models, and moreover as the drug is already approved by FDA for HIV treatment, test could be done soon to see whether this drug can block prostate cancer metastasizing.

This study is build on the prior research of Dr. Pestell’s lab, which in 2012 showed that the receptor CCR5 signaling plays an important role in spreading of aggressive breast cancer to lungs. In the previous paper, they demonstrated that breast cancer cells that carried the CCR5 receptor on their surface were drawn to the lung.

As the prostate cancer cells are attracted towards the bone and brain, Pestell’s team investigated whether CCR5 receptor plays a role in spreading of prostate cancer as well.

With absence of immune competent mouse model having prostate cancer that reliably developed bone and brain metastases, this research was complicated. Thus, the researchers of this study developed a prostate cancer cell line, driven by an up-regulated Src gene that regularly caused bone metastases in immune-competent mouse models.

Developing a mouse model that reflects human disease was important as the immune system is very important in human prostate cancer.

Genes of the metastasized bone and brain tumors were analyzed by the researchers of the study. After analyzing they found out that the genes which are involved in driving the cancer into bone and brain are also involved in CCR5 signaling pathway.

The researchers further investigated by administering drug maraviroc, which is used for blocking CCR5 receptor to the new prostate cancer mouse model. When compared to control mouse, overall metastasizing load to bone, brain and other body organs was dramatically reduced by 60% with maraviroc.

Researchers in order to determine whether a similar mechanism is also found in human prostate cancer, they mined the genomic data of prostate cancer patients.

After mining the data, the researchers found out that CCR5 receptor was more highly expressed in prostate cancer when compared to normal tissue. And also found out that CCR5 receptor was even more highly expressed metastases when compared to primary tumors.

Xuanmao Jiao said that they prostate cancer patients had higher longer survival times that had lower CCR5-pathway genes expression, and prostate cancer patients had shorter survival times that had higher CCR5-pathway genes expression.