Transforming growth factor alpha is trophic to pancreatic cancer in vivo

Pancreatic cancer cell lines overexpress epidermal growth factor (EGF) receptors and also have the capacity to produce transforming growth factor alpha (TGF alpha), the alternate agonist of the EGF receptor. The purpose of this study was to determine if TGF alpha had a trophic effect on the growth of pancreatic cancer in vivo. Syrian golden hamsters were inoculated with 50,000 H2T hamster ductal pancreatic cancer cells. The hamsters were then randomised to three equal groups: the groups received either saline (control), EGF, or TGF alpha, each by intraperitoneal injection, three times a day. Treatment continued for seven weeks, and each week the hamsters were weighed and tumour areas were measured. The hamsters were then killed, and the tumours were excised, weighed, and extracted for assay of DNA content as a measure of cellularity. From week four onwards both EGF and TGF alpha significantly stimulated tumour growth. Although tumour weights were not significantly different, tumour DNA content had nearly doubled after exposure to both EGF and TGF alpha. It is concluded that like EGF, TGF alpha can stimulate pancreatic cancer growth in vivo, and this may in part explain the aggressive nature of these cancers in clinical practice.