c-Myc enhances protein synthesis and cell size during B lymphocyte development

Open Access
Publisher Website
Google Scholar
Abstract
Members of themycfamily of nuclear protooncogenes play roles in cell proliferation, differentiation, and apoptosis. Moreover, inappropriate expression of c-mycgenes contributes to the development of many types of cancers, including B cell lymphomas in humans. Although Myc proteins have been shown to function as transcription factors, their immediate effects on the cell have not been well defined. Here we have utilized a murine model of lymphomagenesis (Eμ-mycmice) to show that constitutive expression of a c-myctransgene under control of the Ig heavy-chain enhancer (Eμ) results in an increase in cell size of normal pretransformed B lymphocytes at all stages of B cell development. Furthermore, we show that c-Myc-induced growth occurs independently of cell cycle phase and correlates with an increase in protein synthesis. These results suggest that Myc may normally function by coordinating expression of growth-related genes in response to mitogenic signals. Deregulated c-mycexpression may predispose to cancer by enhancing cell growth to levels required for unrestrained cell division.