P38 Galanin receptors are correlated with different signaling pathways in human head and neck cancer

Abstract

Introduction Galanin, a small peptide originally associated with neuronal cell function, is highly expressed by some HNSCC cell lines. This peptide can engage three different receptors (GalR1, 2 and 3), which have varying levels of expression in HNSCC cells. High galanin expression and increased galanin receptor 2 (GalR2) signaling were shown to result in increased proliferation, cytokine expression, invasion of HNSCC cells in vitro and also to promote tumor growth in vivo. Less is known about the effect of GalR signaling in the production of soluble mediators that may affect the host response. In fact, little is known about the role of galanin signaling by other receptors and their possible role on the diversity of phenotype of HNSCC cells. In this study, we assessed galanin and GalR1–3 gene expression and the profile of constitutive production of inflammatory cytokines in HNSCC cells. Material and methods We used H-314 and SCC-9 cell lines and normal human oral keratinocytes (NOKsi) as controls. Gene expression of galanin and GalR1–3 was determined by RT-PCR. To explore possible associations between galanin and GalR expression with the phenotype of the HNSCC cells, we determined the constitutive production of a panel of 12 inflammatory mediators by an ELISA focused array. We also assessed the activation of ERK and JNK MAPkinases by western blot. Results Both HNSCC cell lines expressed significantly ( p p p Conclusion These preliminary results suggest that galanin signaling through GalR2 and GalR3 may have distinct effects on the production of soluble biological mediators and consequently influence the phenotype of different HNSCC cells.