Researchers at Purdue have developed what they have described as prostate cancer “homing device.” They believe that this treatment modality can improve detection, and allow for the first targeted treatment of prostate cancer.
The researchers have synthesized a molecule that finds and penetrates only prostate cancer cells. They have also created imaging agents and therapeutic drugs that can link to this molecule and then be carried right to the prostate cancer cell.
Philip Low, the Ralph C. Corley Distinguished Professor of Biochemistry who led the research team claims that this type of targeted treatment will be more effective in treating prostate cancer along with reducing the many harmful side effects associated with current prostate cancer treatments.
“Currently none of the drugs available to treat prostate cancer are targeted, which means they go everywhere in the body as opposed to only the tumor, and so are quite toxic for the patient,” said Low, who is a member of the Purdue Cancer Center.
“By being able to target only the cancer cells, we could eliminate toxic side effects of treatments. In addition, the ability to target only the cancer cells can greatly improve imaging of the cancer to diagnose the disease, determine if it has spread or is responding to treatment,” Low added.
This new molecule is designed to attach to prostate-specific membrane antigen (PSMA), a protein that is found on the membrane of more than 90 percent of all prostate cancers (however, there still are 10% of prostate cancer cells that this molecule would not work on) . Additionally, this molecule is also found on the blood vessels of most solid prostate cancer tumors so it may provide a way to cut the blood supply off that is feeding a tumor.
According to Low, “A lot of new drugs are being designed to destroy the vasculature of solid tumours, and, if they could be linked to this new targeting molecule, we could have a two-pronged attack for prostate cancer. We could not only kill the prostate cancer cells directly, we could also destroy the vasculature that feeds the tumors.”
Animal studies carried out by the researchers have shown the molecule has an ability to eliminate human prostate cancer cells in mice, without any collateral toxicity in normal tissue.
“The molecule acts like a homing device for prostate cancer. PSMA, which is found only on prostate cancer cells and tumor blood vessels, acts as the homing signal that the molecule targets. The molecule and its cargo go only to cancerous tissue, leaving healthy tissue unharmed,” says Sumith Kularatne, a graduate student in Purdue’s chemistry department and first author of both papers who compared the targeting molecule to a homing device.
He has revealed that the molecule is designed with a specific shape that fits with the protein like a key to a lock. The molecule and its cargo are then carried inside the cell with the protein as it goes through its normal cycle.
A radioimaging application used for body scans is expected to enter clinical trials this fall, and an optical imaging application used to measure prostate cancer cells in blood samples is already in clinical trials.
The findings of the researchers have been described in two research articles published in the journal Molecular Pharmaceutics. (ANI)
Of course, remember that more animal studies than not ever make that jump into humans. Other research in other cancers have also demonstrated in animal studies similar positive abilities of using targeted “smart bomb” molecules to deliver drugs directly to tumors.
He potential of this type of delivery system is exciting, but in the usual prostate cancer ay we need to continue to hold on to our hats and do what we do best, WAIT.
Joel T Nowak MA, MSW