ASSESSMENT OF MUSCARINIC AND NICOTINIC ACETYLCHOLINE RECEPTOR EXPRESSION IN PRIMITIVE NEUROECTODERMAL TUMOR/EWING FAMILY OF TUMOR AND DESMOPLASTIC SMALL ROUND CELL TUMOR: AN IMMUNOHISTOCHEMICAL AND WESTERN BLOT STUDY OF TISSUE MICROARRAY AND CELL LINES

Abstract

The primitive neuroectodermal tumor (PNET)/Ewing family of tumors (EFT) and desmoplastic small round cell tumor (DSRCT) portend a grave prognosis. Ongoing research in similar neurocrest-derived neoplasms has implicated both the muscarinic acetylcholine receptor (mAChR) and nicotinic acetylcholine receptor (nAChR) in the pathogenesis of these neoplasms. Acetylcholine has been reported to impart a modulatory effect on chemotaxis and proliferation, an effect ameliorated by anticholinergic drugs. The aim of our study is to characterize the pattern of expression of mAChR and nAChR in PNET/EFT and DSRCT, in hopes of discovering a potential target for therapeutic improvements. We examined 34 cases of PNET/EFT and 2 DSRCT retrospectively by immunohistochemical studies. We found that AChRs are overexpressed in a significant number of PNET/EFT and DSRCT. The Western blot analysis of 3 human Ewing sarcoma cell lines confirms the presence of AChRs. Future studies are planned to confirm these results as well as to investigate their potential therapeutic implications.