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


OBJECTIVE
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 (-) indicating negative expression to (+++) indicating intense positivity.


RESULTS
Mann-Whitney U analysis indicated that no significant differences in expression existed between control and Bcl2 over-expressing 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.
Cadden
I S
IS
Department of Medicine, Queen's University Belfast, Mulhouse Building, RGH, Belfast BT12 6BJ, N. Ireland, UK.
Johnston
B T
BT
Connolly
R
R
Gates
D
D
Tsujimoto
Y
Y
Eguchi
Y
Y
McGinty
A
A
D000818:Animals; D015415:Biomarkers / Q000032:analysis; D002454:Cell Differentiation; D053379:Chromogranin A; D002864:Chromogranins / Q000378:metabolism; D051546:Cyclooxygenase 2; D005786:Gene Expression Regulation; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000378:metabolism; D009490:Neurosecretory Systems / Q000166:cytology* / Q000378:metabolism*; D016716:PC12 Cells; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D015854:Up-Regulation
D015415:Biomarkers; D053379:Chromogranin A; D002864:Chromogranins; D007527:Isoenzymes; D019253:Proto-Oncogene Proteins c-bcl-2; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases