An investigation into the role of Bcl-2 in neuroendocrine differentiation

Abstract

Introduction: In addition to its role in apoptosis suppression, Bcl-2 has been reported to be co-expressed with neuroendocrine markers in several tissues, leading to speculation that this oncoprotein may promote neuroendocrine differentiation.Aim: This study investigated whether Bcl-2 modulated neuroendocrine biopeptide expression. Methods: Levels of chromogranin A, neurone specific enolase, protein gene peptide 9.5, pancreatic polypeptide, and the chromogranin-derived peptides, intervening peptide and vasostatin-1 were examined by immunocytochemistry in rat phaeochromocytoma (PC12) cell lines genetically engineered to over-express Bcl-2 and their mock-transfected controls. Intensity of fluorescence was graded using a semi-quantitative scale from (À) indicating negative expression to (+++) indicating intense positivity.Results: Mann-Whitney U analysis indicated that no significant differences in expression existed between control and Bcl2 overexpressing cell lines for any of the six peptides examined.Conclusions: The results of this study do not support the hypothesis that Bcl-2 promotes the acquisition of a neuroendocrine phenotype.