(PHILADELPHIA) Common blood pressure medications might help block the spread of pancreatic cancer, researchers at the Kimmel Cancer Center at Thomas Jefferson University in Philadelphia have found. The scientists showed in laboratory studies that two types of pressure-lowering drugs ACE inhibitors and AT1R blockers may help reduce the development of tumor-feeding blood vessels, a process called angiogenesis. Such drugs, they say, may become part of a novel strategy to control the growth and spread of cancer.
According to Hwyda Arafat, M.D., Ph.D., assistant professor of surgery at Jefferson Medical College, previous studies have linked a lower cancer incidence with the inhibition of the pancreas hormone angiotensin II (Ang II) by either ACE (Angiotensin I converting enzyme) inhibitors or AT1R (Ang II type 1 receptor) blockers. Ang II increases the production of VEGF, a vascular factor that promotes blood vessel growth in a number of cancers. High VEGF levels have been correlated with poor cancer prognosis and early recurrence. ACE is the enzyme that converts Ang I to Ang II.
Dr. Arafat and her co-workers examined the protein of both invasive pancreatic cancer and normal pancreatic tissue, analyzing the expression of ACE and AT1R in relation to VEGF. They also looked at the effects of blood pressure drugs captopril, an ACE inhibitor, and losartan, an AT1R blocker, on VEGF production in cancer cell lines.
They found that protein levels in ACE and AT1R were significantly higher in 75 percent of the cancer tissue examined. VEGF expression was higher in cases where there was strong ACE and AT1R levels. In the test tube, Ang II significantly enhanced VEGF production in AT1R-positive cells. Captopril and losartan both blocked this effect.
"Our data show for the first time that both ACE and AT1R are functionally expressed in pancreatic ductal adenocarcinoma and suggest their involvement in tumor angiogenesis," Dr. Arafat says. She
Contact: Steve Benowitz
Thomas Jefferson University