Green Government

MALIGNANT TRANSFORMATION of cells may be accompanied by a change in responsiveness to hormonal stimulation. Since hormones exert their effects on cells by binding to specific receptors, the responsiveness of normal or neoplastic tissue to hormonal stimulation is at least partly determined by the presence and concentration of hormone receptors. A number of experimental tumours possess cell-membrane receptors for insulin (Capeau et al., 1978; Harmon & Hilf, 1976; Heuson et al., 1972; Pezzino et al., 1979) and the growth of some of these tumours is affected by changes in the ambient insulin concentration (Cohen & Hilf, 1975; Heuson et al., 1972). Among human tumours, only breast cancer has been shown to possess insulin receptors (Holdaway & Friesen, 1977; Osborne et al., 1978). A variety of cancers have here been studied by us in order to test the hypothesis that most, if not all, human cancers contain specific receptors for insulin. Sixty-seven tissue samples were obtained, including 40 tumours (23 breast carcinomas, 12 colon carcinomas, 2 phaeochromocytomas, a gastric adenocarcinoma, an adrenal carcinoma and a lymphoma), 24 specimens of normal fat and 3 of muscle. All samples were collected at surgery and transported to the Pathology Department on ice. Specimens were carefully dissected free of nontumour tissue, and in any case of doubt a Accepted 20 August 1981