Molecular mechanism underlying differentiation of HL-60 cells induced by hexamethylene bisacetamide / 中国实验血液学杂志

The objective of this study was to investigate the effect of hexamethylene bisacetamide (HMBA) on differentiation of HL-60 cells and its possible molecular mechanism. HL-60 cells were co-cultured with different concentrations of HMBA (0.5, 1, 2 mmol/L) for 4 days, then the proliferation was assayed by MTT at different time points. Wright-Giemsa staining was used to observe the change in morphology. Cell differentiation antigen CD11b expression and the altered distribution of cell cycle in HL-60 induced by HMBA were analyzed by flow cytometry. The expressions of c-myc, mad1, p21, p27, hTERT and HDAC1 mRNA were detected by RT-PCR. The results indicated that the proliferation of HL-60 cells was inhibited by HMBA in a time-and-dose-dependent manner. Upon 2 mmol/L HMBA treatment, the HL-60 cells arrested at G(0)/G(1) phase and differentiated into granular line in morphology, with the up-regulation of CD11b expression. The expression of c-myc and hTERT mRNA obviously down-regulated, the expression of p21, p27 and mad1 mRNA up-regulated, while there was no change of the expression of hTERT mRNA. It is concluded that effect of HMBA on the differentiation of HL-60 cells may partly contribute to switch from c-myc to mad1 expression, to up-regulate expressions of p21 and p27 mRNA, and down-regulate hTERT mRNA expression, while there is no relation with the expression of HDAC1 mRNA.

The molecular mechanisms of As_2O_3- induced un-terminal differentiation of HL-60 cells / 国外医学(肿瘤学分册)

To approach the effect of CCAAT/enhancer binding proteins (C/EBPs) on un-terminal differentiation of HL-60 cells after treatment with Arsenic Trioxide ( As_2O_3) . Methods The changes of cell morphology were observed by Wright staining, the alteration in the cell proliferation was determined by WST1 experiment and the NBT reduction assay was used to detect the differentiation condition of cells, determination and analysis cell cycle. The expressions of C/EBP? and C/EBP? mRNA in HL-60 cells exposed to ATRA and As_2O_3 were assayed by semi-quantitative RT-PCR. Results It was found that ATRA could up- regulate the mRNA expression of C/EBP? obviously, but down-regulate the mRNA expression of C/EBP?. As_2O_3 could up-regulate the mRNA expression of C/EBP? lightly, down-regulate the expression of C/EBP?. Conclusion Both of ATRA and As_2O_3 can down-regulate the mRNA expression of C/EBP?,but there is no significant difference between these two groups,ATRA and As2O3 can up- regulate the mRNA expression of C/EBP?, with significant differences (P