|Top: Collagen (blue) restricts blood vessels (green) in a tumor. Bottom: Losartan allows more blood flow to the tumor, allowing chemo further access.--Courtesy of Massachusetts General Hospital|
Researchers at Massachusetts General Hospital have shown that a proven hypertension drug can help chemotherapy infiltrate solid tumors by opening up collapsed blood vessels in the cancerous mass.
The team published a study in the online journal Nature Communications demonstrating that the hypertension drug losartan, an angiotensin inhibitor, improved the distribution of nanomedicines within a tumor by curbing the production of collagen, which compresses blood vessels in the tumors, limiting the access that chemotherapies might have to those cells. The question was whether the hypertension drug, designed to open up blood vessels throughout the body, would do the same in tumors, according to a hospital report.
In animal trials, the researchers determined that the combination of losartan and chemotherapy drugs helped stem tumor growth and extend survival related to breast and pancreatic cancers.
"Angiotensin inhibitors are safe blood pressure medications that have been used for over a decade in patients and could be repurposed for cancer treatment," senior author Rakesh Jain said in a statement. "Unlike anti-angiogenesis drugs, which improve tumor blood flow by repairing the abnormal structure of tumor blood vessels, angiotensin inhibitors open up those vessels by releasing physical forces that are applied to tumor blood vessels when the gel-like matrix surrounding them expands with tumor growth."
One problem associated with the use of these drugs is that allowing more blood to reach a tumor can actually accelerate tumor growth, but in combination with chemotherapy, the researchers believe the benefits outweigh the consequences.
A clinical trial is now underway to test the effect of the combination in human models.
- here's the report