Examination of PACAP-Like Immunoreactivity in Urogenital Tumor Samples

Numerous studies investigated the localization of pituitary adenylate cyclase-activating polypeptide (PACAP) and its receptors in different tumors and described the effects of analogs on tumor growth to show its potential role in oncogenesis. Recently, our research group has found significantly lower levels of PACAP27-like immunorreactivity (LI) and PACAP38-LI in different human samples of primary small cell lung cancer and colon cancer compared to normal healthy tissues. There are only few human studies showing the presence of PACAP and its receptors in urogenital tumors; therefore, the aim of the present study was to compare PACAP-LI in different healthy and pathological human samples from urogenital organs (kidney, urinary bladder, prostate, testis) with radioimmunoassay (RIA) method. Similar to our earlier observations, the PACAP27-LI was significantly lower compared to PACAP38-LI in all samples. We did not find significant alterations in PACAP-LI between healthy and tumoral samples from the urinary bladder and testis. On the other hand, we found significantly lower PACAP38-LI level in kidney tumors compared with healthy tissue samples, and we showed higher PACAP27-LI in prostatic cancer compared to samples from benign prostatic hyperplasia. These data indicate that PACAP levels of different tissue samples are altered under pathological conditions suggesting a potential role of PACAP in the development of different urogenital tumors.