In situ expression of mRNA for proto-oncogenes in benign prostatic hyperplasia and in prostatic carcinoma

Nine cases of prostatic carcinoma and 5 cases of benign prostatic hyperplasia (BPH) were examined for the in vivo expression of mRNA by an in situ hybridization technique for cellular proto-oncogenes, c-myc, c-fos, and c-sis. The latter of which encodes the B-chain of the platelet-derived growth factor (PDGF). High levels of c-myc and c-sis mRNAs were demonstrated in one highly differentiated prostatic carcinoma. Signals were localized in epithelial cells, both in packed cancer cells and in benign hyperplastic cells with glandular differentiation. A lower level of c-fos mRNA was also detected in the same areas. Four other carcinoma specimens showed c-sis mRNA, three of which also expressed c-fos mRNA. One other carcinoma expressed only c-myc mRNA. Three BPH specimens also contained c-sis and c-fos mRNA with one also exhibiting c-myc mRNA in the glandular epithelial cells. The results support the possibility that local production of growth factors, i.e. PDGF, may play a role in proliferation of prostatic epithelial cells.