| First Author | Damon SE | Year | 1997 |
| Journal | Exp Cell Res | Volume | 237 |
| Issue | 1 | Pages | 192-5 |
| PubMed ID | 9417882 | Mgi Jnum | J:44748 |
| Mgi Id | MGI:1101262 | Doi | 10.1006/excr.1997.3787 |
| Citation | Damon SE, et al. (1997) Developmental regulation of Mac25/insulin-like growth factor-binding protein-7 expression in skeletal myogenesis. Exp Cell Res 237(1):192-5 |
| abstractText | Mac25 is a newly discovered member of the insulin-like growth factor-binding protein (IGFBP) family, recently assigned the name IGFBP-7, Mac25/IGFBP-7 is hypothesized to have growth-suppressing activity, since mac25/IGFBP-7 mRNA is down-regulated in several tumor cell lines and is highly expressed in senescent mammary epithelial cells. In this study, mac25/ IGFBP-7 mRNA expression was characterized in the C2 skeletal myogenic cell line, which undergoes a transition from actively dividing, undifferentiated myoblasts to nondividing, differentiated myotubes. Mac25/ IGFBP-7 mRNA levels were 2.5-fold higher in dividing C2 myoblasts than in nondividing myotubes. The inverse correlation between mac25/IGFBP-7 expression and myogenic differentiation was further examined by treating myogenic cultures with transforming growth factor-beta (TGF-beta) or insulin-like growth factor-I (IGF-I). TGF-beta inhibited myogenic differentiation by 98% and stimulated mac25/IGFBP-7 mRNA expression 2-fold. IGF-I stimulated differentiation by 50% and inhibited mac25/IGFBP-7 expression 2- to 3-fold. These findings indicate that, in contrast to other cell systems examined so far, expression of this new member of the IGFBP family is not always correlated with a nonproliferative state. |
