Overexpression of insulin-like growth factor-binding protein-2 results in increased tumorigenic potential in Y-1 adrenocortical tumor cells.
Increased concentrations of insulin-like growth factor-binding protein-2 (IGFBP-2) have been observed in human malignancies including adrenocortical carcinomas. To elucidate the functional consequences of IGFBP-2 overexpression, we have stably transfected the cDNA of murine IGFBP-2 in mouse adrenocortical tumor cells (Y-1). Long-term overexpression of IGFBP-2 was associated with significant morphological alterations, enhanced cell proliferation, and increased cloning efficiency as compared with mock transfected control cells. The enhanced proliferation of IGFBP-2 secreting clones was independent of exogenous insulin-like growth factors (IGFs). These data suggest that elevated levels of IGFBP-2 may contribute to the highly malignant phenotype of adrenocortical cancer by a thus far unknown, presumably IGF-independent, mechanism.
Hoeflich
A
A
Lehrstuhl für Molekulare Tierzucht und Haustiergenetik/Genzentrum, Ludwig-Maximilians-Universität, Munich, Germany. hoeflich@lmb.uni-muenchen.de
Fettscher
O
O
Lahm
H
H
Blum
W F
WF
Kolb
H J
HJ
Engelhardt
D
D
Wolf
E
E
Weber
M M
MM
D000306:Adrenal Cortex Neoplasms / Q000209:etiology* / Q000378:metabolism / Q000473:pathology; D000818:Animals; D002455:Cell Division; D018971:Insulin-Like Growth Factor Binding Protein 2 / Q000235:genetics / Q000502:physiology*; D007334:Insulin-Like Growth Factor I / Q000235:genetics / Q000378:metabolism; D051379:Mice; D012333:RNA, Messenger / Q000032:analysis; D014407:Tumor Cells, Cultured
D018971:Insulin-Like Growth Factor Binding Protein 2; D012333:RNA, Messenger; D007334:Insulin-Like Growth Factor I