Altered angiotensin-II receptors in human hepatocellular and hepatic metastatic colon cancers.

Abstract

To characterize angiotensin-II receptor density and affinity in normal and cirrhotic livers and in hepatocellular and metastatic colorectal cancer. Several studies have indicated a possible beneficial effect of angiotensin-II as a biologic response modifier in the treatment of hepatic or metastatic colon cancer. This is based on evidence that angiotensin-II will cause a selective increase in arterial vasoconstriction in normal liver compared with tumor. Human hepatoma (5), metastatic colon (10), or cirrhotic (3) liver was obtained. Non-tumor-bearing regions served as normal liver. Angiotensin-II receptor binding was determined on membranes with 125I-angiotensin-II and in situ studies were performed using the biotin-avidin detection system. Angiotensin-II receptor density was markedly down-regulated in tumor compared with normal or cirrhotic liver. A loss of angiotensin-II receptors occurs on the neovasculature of hepatic tumors.