title: Unresponsiveness of both non-rearranged and rearranged c-myc to serum stimulation in a mouse plasmacytoma S194.
abstract: Expression of non-rearranged and rearranged c-myc in a mouse plasmacytoma cell line S194 cultured in different serum concentration or temperature was examined. Exponentially growing S194 cells expressed a high level of rearranged c-myc and a low level of non-rearranged c-myc mRNAs. The levels of the two c-myc mRNAs were nearly the same in the cells in which growth was suppressed by lowering serum concentrations or incubation temperature in culture medium. Furthermore, even when serum-deprived S194 cells resumed growth following serum restimulation, the induction of non-rearranged c-myc mRNA, observed in a mouse T-cell lymphoma cell line BW5147, was not demonstrated. In contrast to the unchanged c-myc expression, the level of N-ras mRNA was related to changes in cell growth rate induced by changes in serum concentration in S194 cells. These results suggest that not only the rearranged c-myc but also the non-rearranged c-myc is unresponsive to serum stimulation and temperature changes, even though cell growth rate is markedly changed.
mesh_terms: D000818:Animals; D001769:Blood; D002453:Cell Cycle; D002455:Cell Division; D005786:Gene Expression Regulation; D051379:Mice; D008807:Mice, Inbred BALB C; D009857:Oncogenes; D010954:Plasmacytoma / Q000235:genetics*; D011061:Poly A / Q000032:analysis; D012313:RNA / Q000032:analysis; D012333:RNA, Messenger
chemical_list: D012333:RNA, Messenger; D011061:Poly A; D012313:RNA