First Author | Grolli S | Year | 1997 |
Journal | Biochem Biophys Res Commun | Volume | 239 |
Issue | 2 | Pages | 566-9 |
PubMed ID | 9344871 | Mgi Jnum | J:43679 |
Mgi Id | MGI:1098340 | Doi | 10.1006/bbrc.1997.7498 |
Citation | Grolli S, et al. (1997) Expression of c-myc is down-regulated as mouse mammary epithelial cells become confluent. Biochem Biophys Res Commun 239(2):566-9 |
abstractText | We have investigated the expression profile of c-myc in the mammary gland. During pregnancy when the gland is actively growing c-myc mRNA was present, while in the differentiated lactating gland no c-myc mRNA was detected. This correspondence between the differentiation state and c-myc mRNA levels in the mouse mammary gland in vivo was paralleled by HC11 mouse mammary epithelial cells in vitro. Firstly, the endogenous c-myc gene was suppressed in confluent compared to growing HC11 cells. In addition, treating the cells with lactogenic hormones did not induce c-myc expression. Secondly, a stably transfected c-myc-CAT reporter construct was similarly down-regulated. Furthermore, using this transfection model, we demonstrate that the mechanism(s) involved in regulating c-myc expression must act through the P1 and P2 core promoter and exon 1. Finally, we demonstrate that suppression of c-myc expression occurs when HC11 cells growth-arrest as they become confluent. Copyright 1997 Academic Press. |