Copyright © 1997 by The Endocrine Society
Expression of the Apoptosis-Suppressing Gene BCL-2 in Pheochromocytoma is Associated with the Expression of C-MYCDa-Gong Wang, Colin F. Johnston, John J. Marley, Kerry V. Phenix, A. Brew Atkinson, Colin F. J. Russell and Keith D. BuchananDivision of Metabolism and Endocrinology, School of Clinical Medicine (D.-G.W., C.F.J., K.D.B.), Molecular & Cell Biology Unit, School of Dentistry (J.J.M., K.V.P.), The Queens University of Belfast, and Sir George E. Clark Metabolic Unit (A.B.A.), Department of Endocrine Surgery (C.F.J.R.), Royal Victoria Hospital, Belfast, United Kingdom Address all correspondence and requests for reprints to: Dr Da-Gong Wang, c/o Colin F. Johnston, Wellcome Research Laboratories, Department of Medicine, Institute of Clinical Science. Grosvenor Road, Belfast BT12 6BJ, United Kingdom. It has become increasingly clear that deregulation of programmed cell death is a critical component in multistep tumorigenesis. Previous studies have demonstrated a high frequency of Bcl-2 expression in tumors arising from cells derived from the neural crest and in tumor cell lines of neural origin. The present investigation was undertaken to determine whether similar molecular events occur in human pheochromocytoma. With the aim of determining the potential role of apoptosis in the pathogenesis of this tumor, we assessed proto-oncogene Bcl-2 and c-myc protein products as well as Bcl-2 messenger RNA levels in a collection of such tumors. Western blot analysis revealed that such tumors expressed the 26 kDa Bcl-2 (5 of 8 cases) and the 64 kDa c-Myc (7 of 8 cases) proteins. Northern blot analysis detected the Bcl-2 transcripts in 6 of 8 tumors. Immunoperoxidase staining, using a monoclonal anti-Bcl-2 antibody, was positive in 18 (82%), including 5 malignant tumors, of the 22 specimens examined. This Bcl-2 immunoreactivity was seen in 14 of 18 (78%) sporadic tumors, including 2 that were extra-adrenal, and all familial tumors. Of the 22 tumor samples examined for c-Myc protein, 20 (91%) tumors were positive. Our results suggest that deregulation of programmed cell death may be a critical component in the multistep tumorigenesis of human pheochromocytoma. The genetic complementation of simultaneously deregulated Bcl-2 and c-myc may be implicated in this process. This article has been cited by other articles:
|
||||||||||||||||||||||||||||||||||||||||||||||