Differential expression of transforming growth factor-beta 1 and beta 3 as well as c-fos mRNA in normal human prostate, benign prostatic hyperplasia and prostatic cancer.

The discrepancy between the incidence of latent prostate cancer and that of clinically overt carcinoma suggests that there can be different courses in the biological progression of prostate cancer. As this cancer is detected increasingly at an infraclinical stage, markers are needed to indicate which lesions will progress and lead to the patient's death. To investigate the possibility that specific growth factors and/or proto-oncogenes are expressed differentially, we measured mRNA levels of transforming growth factors beta 1 (TGF-beta 1), TGF-beta 2 and TGF-beta 3 and of the c-fos and c-jun oncogenes by Northern blotting in normal prostate, benign prostatic hyperplasia (BPH) and prostate cancer. Our data demonstrate that expression of TGF-beta 1 increased, whereas that of TGF-beta 3 fell to an almost undetectable level in carcinoma. Expression of c-fos followed the TGF-beta 1 pattern, whereas no difference could be seen in c-jun expression in cancer as compared with BPH and normal prostate. The differential expression of TGF-beta 1, TGF-beta 3 and c-fos could possibly be used to improve the characterisation of prostate cancer. Long-term follow-up of patients may indicate whether mRNA levels of these growth factors and oncogenes correlate clinically and whether they can be used as markers for progression in human prostate cancer.