CD40 expression in prostate cancer: a potential diagnostic and therapeutic molecule.

CD40, a member of the TNF receptor superfamily, is widely expressed on human immune cells. It is also frequently expressed on epithelial malignancies, suggesting that CD40 may contribute to the pathogenesis of some cancers. Activation of CD40 in cancer cells induces growth inhibition and sensitization to apoptotic stimuli. This study investigates CD40 expression in archival tissue from patients with prostate cancer. In all cases, normal prostatic acini expressed CD40, however, in 56 of 57 cases of prostate cancer no CD40 expression was detected. In the one other case, patchy CD40 expression was associated with prostatic in situ neoplasia. In conclusion, invasive prostate cancer is a CD40-negative turnout. These data may be relevant as a diagnostic tool; in providing insight into progression of cancer from normal epithelium; and in identifying novel therapeutic strategies for prostate cancer.