Kondoh N, Oikawa T, Chiba I, Ogiso Y, Mizuno S, Kuzumaki N
Laboratory of Molecular Genetics, Hokkaido University School of Medicine, Sapporo, Japan.
Leuk Res. 1987;11(12):1149-56. doi: 10.1016/0145-2126(87)90170-6.
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.
检测了在不同血清浓度或温度下培养的小鼠浆细胞瘤细胞系S194中未重排和重排的c-myc的表达情况。呈指数生长的S194细胞表达高水平的重排c-myc和低水平的未重排c-myc mRNA。在通过降低培养基中的血清浓度或培养温度而抑制生长的细胞中，两种c-myc mRNA的水平几乎相同。此外，即使血清剥夺的S194细胞在血清再刺激后恢复生长，也未表现出在小鼠T细胞淋巴瘤细胞系BW5147中观察到的未重排c-myc mRNA的诱导。与c-myc表达不变相反，N-ras mRNA的水平与S194细胞中血清浓度变化诱导的细胞生长速率变化有关。这些结果表明，即使细胞生长速率发生明显变化，不仅重排的c-myc而且未重排的c-myc对血清刺激和温度变化均无反应。
