PML-RARα对环腺苷酸诱导急性髓系白血病细胞分化的影响

Effects of PML-RARα on cAMP-induced AML Cell Differentiation

为了进一步探讨环腺苷酸cAMP协同低剂量氧化砷诱导急性早幼粒白血病细胞分化的分子机制,以稳定转染了PML-RARα融合基因的PR9细胞为实验对象,通过观察细胞的生长,并利用形态学实验、流式细胞技术和荧光素酶报告基因转染实验等检测cAMP和/或氧化砷处理前后细胞相关指标的变化,研究PML-RARα在cAMP诱导AML细胞分化过程中的作用。结果显示,虽然cAMP单独能使表达PML-RARα的PR9细胞表面分化抗原CD11b的阳性率有所升高;但细胞形态学分析表明,cAMP单用无法诱导表达PML-RARα融合蛋白的PR9细胞分化,只有联合氧化砷才能使细胞表现出完全分化的特征,并伴有CD11b表达的显著升高。此外,PML-RARα还可以明显抑制含有cAMP反应元件的报告基因的转录。结论:PML-RARα融合蛋白对cAMP诱导AML细胞分化的信号转导途径具有显著的抑制作用。

To explore the molecular mechanisms of acute promyelocytic leukemia cell differentiation induced by cAMP combined with low-dose As2O3 , the PR9 cell line, which was stably transfected by PML-RARα fusion gene, was used as in vitro model. The effects of PML-RARα on cAMP-induced AML cell differentiation were evaluated according to cell growth, cell morphology, cell surface antigen as well as luciferase reporter gene assay, in the cells before and after the treatment with cAMP and/or AS2O3. The results showed that cAMP alone could slightly increase the expression of CDllb in the PR9 cells expressing the PML-RARα fusion protein, but could not induce these cells to differentiate. The cells presented the terminal differentiation morphology and significantly increased CD11b expression only under the treatment of cAMP combined with As2O3. In addition, PML-RARα had strong inhibitory activity on the transcription of the reporter gene containing cAMP response elements. In conclusions, the PML-RARα fusion protein could dramatically block the signaling pathway of cAMP during the AML cell differentiation.