First Author | Adesanya OO | Year | 1999 |
Journal | Proc Natl Acad Sci U S A | Volume | 96 |
Issue | 6 | Pages | 3287-91 |
PubMed ID | 10077676 | Mgi Jnum | J:53580 |
Mgi Id | MGI:1332954 | Doi | 10.1073/pnas.96.6.3287 |
Citation | Adesanya OO, et al. (1999) Insulin-like growth factor 1 is required for G2 progression in the estradiol-induced mitotic cycle. Proc Natl Acad Sci U S A 96(6):3287-91 |
abstractText | Insulin-like growth factor 1 (IGF1) has been proposed as a G1-progression factor and as a mediator of estradiol's (E2) mitogenic effects on the uterus. To test these hypotheses, we compared E2's mitogenic effects on the uteri of Igf1-targeted gene deletion (null) and wild-type littermate mice. The proportion of uterine cells involved in the cell cycle and G1- and S-phase kinetics were not significantly different in wild-type and Igf1-null mice. However, the appearance of E2-induced mitotic figures and cell number increases were profoundly retarded in Igf1-null uterine tissue. There was a significant increase in nuclear DNA concentration in Igf1-null cells, consistent with a G2 arrest. Interestingly, apoptotic cells were also significantly reduced in abundance, and the normal massive apoptotic response to E2 withdrawal was absent in the Igf1-null uterus. These data show that Igf1 is an essential mediator of E2's mitogenic effects, with a critical role not in G1 progression but in G2 progression. |