The orexin type 1 receptor is overexpressed in advanced prostate cancer with a neuroendocrine differentiation, and mediates apoptosis.

Aim: In the present study, we have examined the presence of orexins and their receptors in prostate cancer (CaP) and investigated their effects on the apoptosis of prostate cancer cells.

Methods: We have localised the orexin type 1 and 2 receptors (OX1R and OX2R) and orexin A (OxA) in CaP sections of various grades and we have quantified tumour cells containing OX1R. Expression of OX1R was evaluated in the androgeno-dependent (AD) LNCaP and the androgeno-independent (AI) DU145 prostate cancer cells submitted or not to a neuroendocrine differentiation.

The neuropeptide 26RFa is expressed in human prostate cancer and stimulates the neuroendocrine differentiation and the migration of androgeno-independent prostate cancer cells.

Aim: Accumulating data suggest that neuropeptides produced by neuroendocrine cells play a crucial role in the progression and aggressiveness of hormone refractory prostate cancer (CaP). In this study, we have investigated the presence and function of the neuropeptide 26RFa in CaP.

Methods: We have localised and quantified tumour cells containing 26RFa and its receptor, GPR103, in CaP sections of various grades.