The protein that the drug targets is called PAK-1, and this protein is known to contribute to the formation of invasive prostate cancer cells. PAK-1 has been described as a type of ‘on-off’ switch; when it is activated, it leads to cancerous cells becoming metastatic cells and these then begin to spread through the body.
To combat the functioning of PAK-1 the scientists developed a small counter molecule called IPA-3, designed to slowdown the activity of PAK-1 proteins. To ensure the IPA-3 molecule has an unaffected path through the body to reach the site of the cancerous cells, it is encased in a protective shell formed from liposome. Liposome protects the molecule from being metabolized by the body too rapidly.
The drug molecule is injected directly into the blood stream. On reaching its target, the molecule is capable of disrupting the PAK-1 protein. Without liposome, the drug would need to be administered daily; with the coating, due to the longevity of the molecules in the body, the treatment regime can be reduced, trials showed, to twice-weekly.
Trials using the drug have been conducted using mice. The trials were successful in that the progression of cancer was slowed down. The molecule was also effective at destroying cancer cells by triggering them to undergo cell death (through apoptosis.) The success of this is likely to lead to further animal studies and, if the success rate continues, to human studies.
Given that prostate cancer is one of the major forms of cancer, the research is likely to attract further interest and this will lead to additional trials. The study was conducted at the University of Georgia. The findings are published in the journal Nanomedicine: Nanotechnology, Biology and Medicine. The research is titled “Liposomal-mediated delivery of the p21 activated kinase-1 (PAK-1) inhibitor IPA-3 limits prostate tumor growth in vivo.”
In related news, long-term results from a recent U.S. government backed study have eased concerns about the safety of a hormone-blocking drug that, through trials, appears to lower a man’s chances of developing prostate cancer. The drug reviewed, in its generic form is called finasteride (the label claim on the medicine for the treatment of benign prostatic hyperplasia). Commercially the drug is manufactured as Proscar, by Merck & Co.