EXPRESSION OF ESTROGEN-RECEPTOR AND ESTROGEN-INDUCIBLE GENES IN PANCREATIC-CANCER

Background Previous studies have not been able to demonstrate convinci ngly whether the human pancreas expresses oestrogen receptor and wheth er there is any benefit from antioestrogen therapy in advanced pancrea tic cancer. Methods Oestrogen receptor expression was assessed in norm al human pancreas and pancreatic cancer tissue by enzyme immunoassay, Northern blot analysis, in situ hybridization and immunohistochemistry . The expression of the oestrogen-inducible proteins, progesterone rec eptor, pS2 and ERDS was also examined. Results A mean of 1.0 (range 0- 2.4) fmol oestrogen receptor per mg protein was detected in normal pan creas and 0.5 (range 0-1.2) fmol mg(-1) in pancreatic cancer. Messenge r RNA for oestrogen receptor was detected in both normal and cancerous pancreas. In situ hybridization and immunohistochemistry, however, fa iled to localize oestrogen receptor expression. Mean (range) expressio n of progesterone receptor in normal and neoplastic pancreas was 1.9 ( 0.5-3.5) and 2.5 (0.3-9.3) fmol mg(-1) respectively, pS2 and ERDS were also expressed in normal tissue and pancreatic cancer, and expression was localized to ductular epithelium. Conclusion The amount of oestro gen receptor detected in pancreatic tissue was small, and may account for previous difficulties in its detection. The extent to which it is functional in both the normal and malignant pancreas warrants further investigation.