DEMONSTRATION OF LOW-DENSITY-LIPOPROTEIN RECEPTOR IN HUMAN COLONIC-CARCINOMA AND SURROUNDING MUCOSA BY IMMUNOENZYMATIC ASSAY

In order to verify the presence of Low Density Lipoprotein Receptor (L DLR) in cellular membranes isolated from human colonic tissue, samples from the neoplastic colorectum and the normal surrounding mucosa were studied by an enzyme-linked-immunosorbant assay. A monoclonal antibod y against the human LDLR was used. The LDLR content revealed a conside rable inter-individual variation. In 36 out of 53 cases (68%) there wa s no LDLR presence in either normal or neoplastic tissue samples. In 5 out of 53 cases (9.4%), LDLRs were detected in both types of tissue s amples, in 9 cases out of 53 (17%) LDLRs were present in neoplastic ti ssue, while in 3 out of 53 cases (5.6%) only in normal mucosa. The ant i-LDLR mono-clonal antibody (mAb) binding was significantly higher in neoplastic tissue samples than normal surrounding colonic mucosa ones. Sex, age, body mass index (BMI), serum cholesterol, tumour site, hist ologic grading and Dukes' stage did not seem to be associated with LDL R presence.