Substance‐P receptors in human primary neoplasms: Tumoral and vascular localization

Publisher Website
Google Scholar
Abstract
Primary human neoplasms were examined for the presence of substance‐P receptors by receptor autoradiography with 125I‐labelled Bolton‐Hunter substance P. Substance‐P receptors were localized and characterized in the neoplastic cells of 9/12 astrocytomas, 10/10 glioblastomas, 10/12 medullary thyroid carcinomas, 8/16 breast carcinomas and 4/5 ganglioneuroblastomas. Conversely, substance‐P receptors were not or only rarely identified on non‐small‐cell carcinomas of the lung (1/16), neuroblastomas (0/8), adenocarcinomas of the colon (1/21) or the pancreas (1/9), or on malignant lymphomas (3/18). However, in the great majority of the investigated tumours, substance‐P receptors were found on intra‐ and peritumoral blood vessels. All substance‐P receptors detected had the pharmacological characteristics of the neurokinin‐I receptor sub‐type. In addition, the expression of somatostatin receptors was examined in all the neoplastic tissues mentioned above. Both substance‐P and somatostatin receptors were present in astrocytomas and in ganglioneuroblastomas, whereas little or no receptor was found in pancreatic and non‐small‐cell lung carcinomas. The extent of somatostatin‐receptor expression was inversely correlated to that of the substance‐P receptors in glioblastomas, neuroblastomas and non‐Hodgkin's lymphomas. The tumoral and vascular localization of substance‐P receptors in tumours may have clinical implications. The use of radiolabelled substance P for in vivo scintigraphy may supplement the current set of diagnostic tools. Substance‐P antagonists might be used in the treatment of tumours, as their binding to vascular receptors may decrease tumoral blood supply and drainage. © 1995 Wiley‐Liss, Inc.