The role of c-myc in cellular growth control

Cell division is coupled to cell growth. Since some c-myc target genes are regulators of cell growth while others function in cell division pathways, c-myc is apparently poised at the interface of these processes. Cell cultur e systems have shown specific myc-associated growth phenotypes, Increased c ell growth precedes DNA synthesis after myc activation in cells expressing myc-estrogen receptor fuson constructs and cells lacking c-myc exhibit a ma rked loss of protein synthesis. A number of candidate c-myc target genes re gulate processes required for cell growth including rRNA transcription and processing, ribosomal protein transcription and translation, and translatio n initiation. These interactions all have the potential to account for the growth phenotypes in c-myc mutant cells. The ability of translation initiat ion factors, including eIF4E, to transform cells makes them particularly in teresting targets of c-myc. Further evaluation of these target genes will p rovide important insights into growth control and c-myc's functions in cell ular proliferation.