The intertwining roles of caveolin, oxytocin receptor, and the associated signalling pathways in prostate cancer progression.

Abstract

Caveolae are invaginations in the plasma membrane of most cell types and are present in the cells of normal prostate tissue. Caveolins are a family of highly conserved integral membrane proteins that oligomerise to form caveolae and interact with signalling molecules by providing a scaffold that sequesters signal transduction receptors in close proximity to each other. Signal transduction G proteins and G-protein-coupled receptors (GPCR), including oxytocin receptor (OTR), are localised within caveolae. Only one OTR has been identified, and yet, this single receptor both inhibits and stimulates cell proliferation. As caveolae sequester lipid-modified signalling molecules, these differing effects may be due to a change in location. The cavin1 necessary for caveolae formation is lost in prostate cancer progression. With the loss of caveolae, the OTR moves out onto the cell membrane influencing the proliferation and survival of prostate cancer cells. Caveolin-1 (cav-1) is reportedly overexpressed in prostate cancer cells and is associated with disease progression. This review focuses on the position of OTRs within caveolae, and their movement out onto the cell membrane. It explores whether movement of the OTR is related to changes in the activation of the associated cell signalling pathways that may increase cell proliferation and analyse whether caveolin and particularly cavin1 might be a target for future therapeutic stratagies.