Publications (2)0 Total impact
ABSTRACT: Vasoactive intestinal peptide (VIP) is involved in prostate cell proliferation and function. VIP and pituitary adenylate cyclase-activating peptide (PACAP) are similarly recognized by VPAC1/VPAC2 receptors whereas PACAP binds with higher affinity than VIP to PAC1 receptor. Here we systematically studied the presence and distribution of functional PAC1, VPAC1 and VPAC2 receptors in human normal and malignant prostate tissue. Functional PACAP/VIP receptors were detected in normal and malignant prostate by adenylyl cyclase stimulation with PACAP-27/38 and VIP. RT-PCR experiments showed PAC1 (various isoforms due to alternative splicing), VPAC1 and VPAC2 receptor expression at the mRNA level, whereas Western blots found the three receptor protein classes in normal and pathological conditions. No conclusive differences could be established when comparing control and cancer tissue samples. Immunohistochemistry showed a weaker immunostaining in tumoral than in normal epithelial cells for the three receptor subtypes. In conclusion, we demonstrate the expression of functional PAC1, VPAC1 and VPAC2 receptors in human prostate as well as its maintenance after malignant transformation.
ABSTRACT: The presence, expression and distribution of pituitary adenylate cyclase-activating peptide (PACAP) in human prostate cancer and healthy tissue were investigated by means of biochemical and morphological procedures. Reverse transcription-polymerase chain reaction (RT-PCR) analysis demonstrated the presence of its precursor encoding mRNA in both normal and pathological conditions (amplification products with 577 or 226 bp were identified). Immunochemistry using an appropriate antibody served to detect in both classes of tissues a 19.9-kDa product corresponding to the PACAP preproprotein and another protein of 14.6 kDa that may represent a product partially processed by convertases. However, a 5-kDa band characteristic of PACAP-38 peptide was not observed. Immunohistochemistry on tissue sections indicated the location of PACAP in the epithelial layer of prostate glands (and in some scarce leucocytes) but not in the stroma, either in normal or carcinomatous tissues. No clear differences could be established when comparing samples from patients with different tumor Gleason grades. These results are the first demonstration of the localization of PACAP or its precursors and its mRNA in the human prostate gland and their presence during the progression of prostate carcinoma.