Horm Metab Res 2007; 39(12): 876-883
DOI: 10.1055/s-2007-993135
Original Basic

© Georg Thieme Verlag KG Stuttgart · New York

Chromogranin A Expression in Phaeochromocytomas Associated with von Hippel-Lindau Syndrome and Multiple Endocrine Neoplasia Type 2

S. Cleary 1 , 2 , J. K. Phillips 2 , T-T. Huynh 1 , K. Pacak 3 , S. Fliedner 3 , A. G. Elkahloun 4 , P. Munson 5 , R. A. Worrell 6 , G. Eisenhofer 1
  • 1Clinical Neurocardiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
  • 2Division of Health Sciences, Murdoch University and Western Australian Biomedical Research Institute, Perth, WA, Australia
  • 3Reproductive Biology and Medicine Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
  • 4Genome Technology Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
  • 5Mathematical and Statistical Computing Laboratory, Center for Information Technology, National Institutes of Health, Bethesda, Maryland, USA
  • 6Urologic Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
Further Information

Publication History

received 29.01.2007

accepted 14.05.2007

Publication Date:
28 November 2007 (online)

Abstract

Chromogranin A (CGA) is a major secretory protein present in the soluble matrix of chromaffin granules of neuroendocrine cells and tumours, such as phaeochromocytomas. CGA has several functions, some of which may be involved in the distinct phenotypic differences of phaeochromocytomas in patients with von Hippel-Lindau (VHL) syndrome compared to multiple endocrine neoplasia type 2 (MEN 2). In this study, we therefore compared tumour and plasma levels of CGA in patients with phaeochromocytoma associated with the two syndromes. We show that phaeochromocytomas from MEN 2 patients express substantially more CGA than tumours from VHL patients at both the mRNA (3-fold greater) and protein (20-fold) level. We further show that relative to increases in plasma catecholamines, patients with phaeochromocytomas associated with MEN 2 have higher plasma concentrations of CGA than those with tumours in VHL syndrome. These data supplement other observations that phaeochromocytomas in VHL compared to MEN 2 patients express lower amounts of catecholamines and other chromaffin granule cargo, such as chromogranin B and neuropeptide Y. Possibly the differences in tumour CGA expression may contribute to differences in secretory vesicle formation and secretion in the two types of tumours. Alternatively the differences in expression in CGA and other secretory constituents may reflect downregulation of the entire regulated secretory pathway in VHL compared to MEN 2 tumours.

References

Correspondence

S. Cleary

School of Veterinary and Biomedical Sciences

Murdoch University

6150 Perth WA

Australia

Phone: +61/89/360 66 92

Fax: +61/89/310 41 44

Email: [email protected]