EXPRESSION OF APOPTOSIS-SUPPRESSING GENE BCL-2 IN HUMAN CAROTID-BODY TUMORS

That carotid body tumours have a genetic aetiology is suggested by the familial occurrence of the neoplasm. Environmental influences are als o implied by the fact that the tumour is more common in those living a t high altitudes, However, the mechanism of development of sporadic tu mours occurring at sea level, which account for the majority of cases, remains unknown. It has become increasingly clear that the deregulati on of programmed cell death is a critical component in multistep tumou rigenesis. Previous studies have demonstrated a high frequency of bcl- 2 expression in the tumours arising from cells derived from the neural crest and tumour cell lines of neural origin, This investigation mas undertaken to determine whether similar molecular events occur in huma n carotid body tumours. Western and Northern analysis revealed that th e tumours expressed the 26 kD protein and bcl-2 transcripts. Immunoper oxidase staining, using a monoclonal anti-bcl-2 antibody, revealed tha t 11 out of 13 specimens stained positively for bcl-2. These results s uggest that the deregulation of programmed cell death may be a critica l component in the multistep tumourigenesis of carotid body tumours an d that the expression of oncoprotein bcl-2 may contribute to the gener ation of such tumours. (C) 1997 John Wiley & Sons, Ltd.