[A study of epidermal growth factor receptor in human colorectal cancer]

Membrane extracts of surgically resected colorectal cancer and nearby non-cancerous tissues were prepared and the expression of epidermal growth factor receptor (EGF-R) was examined by 125I-EGF binding assay. Scatchard analysis indicated that a single class of EGF-R was present in the cancer as well as the non-cancerous tissues. EGF-R was found over-expressed in cancer (38.07 +/- 4.75 fmol/mg protein) as compared to that in the non-cancerous tissue (29.31 +/- 1.64 fmol/mg protein) (P < 0.05). However, the difference in binding affinities of EGF-R in the cancer and non-cancerous tissues was not statistically significant. The results suggest an important role of an autocrine/paracrine loop of growth regulation in colorectal cancer.