c-Myc enhances protein synthesis and cell size during B lymphocyte development.
Members of the myc family of nuclear protooncogenes play roles in cell proliferation, differentiation, and apoptosis. Moreover, inappropriate expression of c-myc genes 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 (Emu-myc mice) to show that constitutive expression of a c-myc transgene under control of the Ig heavy-chain enhancer (Emu) 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-myc expression may predispose to cancer by enhancing cell growth to levels required for unrestrained cell division.
Iritani
B M
BM
Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109-1024, USA.
Eisenman
R N
RN
D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology*; D002453:Cell Cycle; D048429:Cell Size / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D016271:Proto-Oncogene Proteins c-myc / Q000096:biosynthesis / Q000502:physiology*; D019076:Transgenes
D016271:Proto-Oncogene Proteins c-myc