c-myb反义寡脱氧核苷酸对白血病细胞HL-60的生物效应

为了研究c-myb在髓系白血病细胞的增殖和分化中所起的调控作用,合成了与c-myb mRNA翻译起始区域互补的一段反义寡脱氧核苷酸(18bp),将其作用于白血病细胞系HL-60细胞,观察到细胞生长抑制率平均为55%。经过c-myb反义寡脱氧核苷酸片段作用HL-60细胞,c-myb mRNA的表达不能被RT-PCR方法检测到,而在未加反义序列组和加随机序列组细胞中则能检测c-myb的表达。NBT染色后在Wright-Giemsa细胞涂片上可观察到未经处理和随机序列处理的95%HL-60细胞处于未分化阶段,经过c-myb反义寡脱氧核苷酸作用后的细胞中NBT阳性细胞占50％,部分细胞出现分化状态。

Effects of c-myb Antisense Oligodeoxynucleotides to Leukemia Cell Line HL-60 Cells

To study the role of the proto-oncogene c-myb in regulating myeloid leukemia cell proliferation and differentiation, the cells of the human leukemia line HL-60 cells were exposed to an oligodeoxynu-cleotide complementary to an 18-base-pair(bp) sequence of c-myb-encoded mRNA. After 5 days in culture, 47% - 64% growth inhibition was observed in c-myb antisense treated cells in comparison to untreated HL-60 cells. Growth inhibition was not observed in random oligomer sequence treated cells. The c-myb mRNA expression by RT-PCR also was examined. The result was that c-myb mRNA expression was inhibited by antisense oligomer while c-myb mRNA expression was detected in untreated HL-60 cells; the differentiated phenotype was determined by NBT and Wright-Giemsa stain. About 50% of HL-60 cells exposed to c-myb antisense oligormer were NBT-positive and showed morphological changes with differentiated phenotype, while <5% of untreated cells were NBT-positive. These studies indicate that the nuclear protein encoded by the c-myb proto-oncogene is required for maintenance of proliferation in certain leukemia cell line and may be involved in the differentiation of myeloid leukemia cells. It also suggests that perturbation of c-myb function with antisense oligodeoxynu-cleotides might eventually be the basis for molecular approach to treat leukemia, perhaps, as an ex vivo bone marrow purging agent.