雷帕霉素抑制DNMT3A突变相关急性髓系白血病的发展

Rapamycin inhibiting the progression of acute myeloid leukemia with DNMT3A mutation

目的·应用小鼠模型,探索雷帕霉素靶蛋白(mammalian target of rapamycin,m TOR)抑制剂雷帕霉素治疗DNA甲基转移酶3A(DNA methyltransferase 3A,DNMT3A)R882突变相关急性髓系白血病(acute myeloid leukemia,AML)的效果。方法·将携带DNMT3A R882突变的人AML细胞株OCI-AML3在体外培养,分别给予雷帕霉素或者二甲基亚砜(dimethyl sulfoxide,DMSO)处理后,由尾静脉注射给半数致死量辐照后的NOD/SCID免疫缺陷小鼠,观察2组小鼠的疾病进展情况。监测小鼠的血常规,通过流式细胞术检测人CD45+细胞即OCI-AML3细胞比例变化,记录小鼠生存时间,取小鼠骨髓、脾脏、肝脏进行病理和流式等分析。结果·雷帕霉素组小鼠外周血白细胞与DMSO组相比升高趋势明显减缓,外周血CD45+细胞比例为(4.44±2.58)%(移植后1周)和(34.42±13.64)%(移植后2周),均低于同时期DMSO组的(16.71±8.96)%和(51.55±5.36)%;雷帕霉素组小鼠中位生存期27 d,相较DMSO组中位生存期23 d明显延长。雷帕霉素组骨髓、脾脏和肝脏中CD45+细胞浸润比例均小于5%,明显低于DMSO组脾脏([51.32±27.81)%]和肝脏[(50.03±28.74)%]中的比例;雷帕霉素组小鼠脾脏大小明显小于DMSO组,脾脏浸润和结构破坏明显减轻。结论·在携带DNMT3A R882突变的AML免疫缺陷小鼠模型中,雷帕霉素可有效抑制DNMT3A R882突变的AML的进展。

Objective·To investigate the effect of mammalian target of rapamycin(mTOR)inhibitor rapamycin on acute myeloid leukemia(AML)with DNA methyltransferase 3A(DNMT3A)R882 mutation in mouse model.Methods·AML cell line OCI-AML3 cells with DNMT3A R882 mutation were cultured with the treatment of rapamycin or DMSO,and then these cells were injected into the tail vein of sublethally irradiated NOD/SCID mice,respectively.The disease progression was monitored by blood routine examination and flow cytometry analysis of CD45+,OCI-AML3 cells,in peripheral blood.Survival time was recorded.Samples from bone marrow,spleen and liver were harvested for flow cytometry analysis and pathological examination.Results·The increasing trend of peripheral leukocytes in the rapamycin treated group was obviously slower than that in the DMSO treated group.The proportion of peripheral blood CD45+cells in the rapamycin treated group was(4.44±2.58)%(1 week after transplantation)and(34.42±13.64)%(2 weeks after transplantation),which were lower than(16.71±8.96)%and(51.55±5.36)%in the DMSO treated group in the same period,respectively.The median survival time of the rapamycin treated group(27 d)was significantly longer than that of the DMSO group(23 d).The ratios of CD45+cell infiltration in bone marrow,spleen and liver of the rapamycin treated group were all less than 5%,which were significantly lower than those[(51.32±27.81)%in spleen and(50.03±28.74)%in liver]of the DMSO treated group.Compared with the DMSO treated group,the spleen size of the mice was significantly smaller,and the spleen infiltration and structural damage were significantly alleviated in the rapamycin treated group.Conclusion·Rapamycin shows effective inhibition on the progression of AML with DNMT3A R882 mutation in NOD/SCID mouse model.