Chen Z X
Jiangsu Institute of Hematology, Suzhou.
Zhonghua Zhong Liu Za Zhi. 1991 Jul;13(4):261-4.
Modulation of a number of protooncogene expression occurs during differentiation of eukaryotes. Changes in expression of c-myb and c-myc during the HMBA-induced terminal differentiation of murine erythroleukemia cells were characterized by an early decrease (within 4 hrs), followed by the recovery of c-myc mRNA by 10 hrs, and the retention of suppression of c-myb expression for the rest of the induction period. Two MELC variants were used to further define the relationship between the differentiation and the protooncogene expression. R1 was a MELC variant completely resistant to HMBA, and R1 (VCR), a vincristine resistant R1, became inducible by HMBA again. The cell differentiation and the c-myb and c-myc expression were determined on R1 or R1 (VCR) cultured with HMBA respectively. The results demonstrated that the c-myc mRNA increased and remained relatively high as the cells grew to a saturated density regardless of the induction of differentiation. The R1 (VCR) cultured with HMBA displayed an early decrease in c-myb mRNA and a subsequent suppression of its expression, while the R1 cultured with HMBA showed a stable level of c-myb mRNA. These results suggest that the c-myb expression, rather than c-myc expression, is closely related to the HMBA-induced terminal differentiation.
在真核生物分化过程中会发生多种原癌基因表达的调节。在六亚甲基双乙酰胺（HMBA）诱导的小鼠红白血病细胞终末分化过程中，c-myb和c-myc表达的变化特点是早期下降（4小时内），随后c-myc mRNA在10小时时恢复，并且在诱导期的剩余时间内c-myb表达持续受到抑制。使用两种小鼠红白血病细胞（MELC）变体进一步确定分化与原癌基因表达之间的关系。R1是对HMBA完全抗性的MELC变体，而R1（VCR），一种长春新碱抗性的R1，再次变得可被HMBA诱导。分别在与HMBA培养的R1或R1（VCR）上测定细胞分化以及c-myb和c-myc表达。结果表明，无论是否诱导分化，随着细胞生长至饱和密度，c-myc mRNA都会增加并保持相对较高水平。用HMBA培养的R1（VCR）显示c-myb mRNA早期下降，随后其表达受到抑制，而用HMBA培养的R1显示c-myb mRNA水平稳定。这些结果表明，与HMBA诱导的终末分化密切相关的是c-myb表达，而非c-myc表达。
