ABSTRACT
Patients with carcinoma of the pancreas exhibit a very high mortality rate. The reasons for the aggressiveness of this cancer are not known, and the factors that regulate the proliferation of pancreatic cancer cells have been clearly delineated. To elucidate the general mechanisms that contribute to epidermal growth factor (EGF) receptor overexpression in these cell lines, we carried out molecular studies using an EGF receptor cDNA in dot blot, slot blot, and Northern blot types of analysis. EGF is not readily degraded in these cells, but is recycled between the intracellular and extracellular compartments, a phenomenon which may allow one EGF molecule to induce the internalization and degradation of numerous EGF receptors. Theoretically, the release of biologically active EGF by pancreatic cancer cells may also allow for its local accumulation, resulting in its enhanced availability to a variety of cell types that are present within a pancreatic tumor mass.
