Detection of Ob-receptor in human adrenal neoplasms and effect of leptin on adrenal cell proliferation.
Leptin, a hormone mainly secreted from adipose tissue, communicates a metabolic signal to the adrenal gland. Ob-Receptor (Ob-R) expression was reported in rat, mice and human adrenal glands. This study intended to investigate possible differences in the Ob-R expression and distribution of Ob-R protein in human adrenal tumors as compared to normal adrenal tissue. Proliferative effects of leptin were analyzed in the human adrenocortical carcinoma cell line (NCI-H295). The full length Ob-R mRNA and the isoforms B219.1 and B219.3 could be demonstrated by RT-PCR in all adrenal tumors (n=8), the tumor cell line (NCI-H295) and normal tissue. In contrast the Ob-R isoform B219.2 was absent in the carcinoma cell line and in most of the adrenal tumors (n=5), whereas it was present in normal adrenals. The Ob-R protein could be demonstrated in benign and malignant adrenocortical tumors. Pheochromocytomas showed only a weak immunostaining with the human Ob-R antibody. Human leptin did not affect the proliferation or variability of adrenal tumor cells as demonstrated by [3H]-thymidine assay and WST-1 test. In conclusion, although functional leptin receptors are expressed in human adrenal tumors, leptin does not regulate tumor cell proliferation.
Glasow
A
A
Department of Internal Medicine III, University of Leipzig, Germany. glasowa@medizin.uni-leipzig.de
Bornstein
S R
SR
Chrousos
G P
GP
Brown
J W
JW
Scherbaum
W A
WA
D000236:Adenoma / Q000737:chemistry / Q000473:pathology; D000306:Adrenal Cortex Neoplasms / Q000737:chemistry / Q000473:pathology; D000310:Adrenal Gland Neoplasms / Q000737:chemistry* / Q000473:pathology; D000311:Adrenal Glands / Q000737:chemistry; D000328:Adult; D002352:Carrier Proteins / Q000032:analysis* / Q000235:genetics; D002455:Cell Division / Q000187:drug effects*; D002470:Cell Survival; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D020738:Leptin; D008875:Middle Aged; D010673:Pheochromocytoma / Q000737:chemistry / Q000473:pathology; D011506:Proteins / Q000494:pharmacology*; D012333:RNA, Messenger / Q000032:analysis; D011956:Receptors, Cell Surface; D054411:Receptors, Leptin; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured
D002352:Carrier Proteins; C515448:LEPR protein, human; D020738:Leptin; D011506:Proteins; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D054411:Receptors, Leptin