RbAp46基因过度表达抑制K562白血病细胞的生长

Effect of overexpression of RbAp46 on the biological behavior of K562 leukemia cell line

目的探讨RbAp46基因对白血病细胞的作用机制。方法利用脂质体将全长RbAp46基因的cDNA片段及空载体PCB6+转入K562细胞株,分别进行生长曲线、软琼脂集落培养及细胞周期的检测,比较两者的差异。结果与空载体K562/PCB6+细胞比较,过度表达RbAp46基因的单克隆细胞株生长减慢,生长第4天,两者细胞数分别为(9.00±0.84)×105和(11.96±0.99)×105;集落减少[K562/RbAp46 vs K562/PCB6+为(131.67±15.57)vs(250.33±26.31),P<0.01];细胞周期改变主要表现为S期细胞减少[(48.88±4.35)vs(62.78±4.78),P<0.01)],G0/G1期细胞增多[(29.10±4.14)vs(22.40±2.43),P<0.05)]。结论作为抑癌基因,RbAp46通过抑制DNA合成而抑制K562细胞株的增殖。

Objective To explore the effects of RbAp46 expression on leukemia cells in vitro. Methods K562 leukemia cells were transfected by vector pCB6-RbAp46 and pCB6-PCB6＋ mediated by DMRIE-C. K562 transfectants with RbAp46 overexpression were selected and subcloned by limited dilution. Growth curve and colony formation assay on methocellulose semi-solid medium were performed to examine the proliferation capability of K562 transfectant. Cell cycle arrest was determined by flow cytometry analysis. Results The transfected K562 subclone overexpressing RbAp46 grew more slowly than that in the control vector. On the 4th day, the cell densities were （9. 0±0. 84） ）〈 10^5 and （11.96±0. 99）× 10^5 , respectively. The cells overexpressing RbAp46 formed less colonies than those the empity vector （131.67±15.57 vs 250. 33±26. 31,P〈0. 01）. The proportion of S cell population was lower（48. 88±4. 35 vs 62. 78±4. 78, P〈0. 01） and G0〈G1 cell population was higher in K562 cells transfected by RbAp46 than that transfected by control vector（ 29. 10±4. 14 vs 22. 40± 2. 43, P〈0. 05）. Conclusion The growth inhibitory effect of RbAp46 overexprssion on K562 leukernia cells may be exerted through inhibition of DNA synthesis.