The Molecular Mechanisms Of Long Non-coding RNA MEG3 To Effect The Growth Of Acute Myeloid Leukemia

Objective: Acute myeloid leukemia(AML) is one of the most common types of leukemia. The prognosis of AML is poor, and the long-term survival rate is only 5-16%. At present, it has been found that the pathogenesis of AML is associated with many factors, such as recurrent somatic mutation and gene expression and epigenetic changes. However, the pathogenesis of AML molecular mechanism is still unclear. Thus, there is a pressing need to deeply investigate the molecular mechanism of AML.Long non-coding RNA(lnc RNA) is a kind of RN A longer than 200 bp, without the function of protein coding. Lnc RNAs are involved in many biologica l processes, such as regulate chromatin remodeling, DN A methylation and histone modification, profoundly affecting the occurrence and development of diseases, especially tumor. Long non-coding RNA MEG3 is a newly found tumor suppressor and plays a very important role in the regulation of a variety of tumor formation and progression. Studies found that the MEG3 expression was significantly decreased in acute myeloid leukemia(AML). However, to date, it is not clear the cause of its abnormal expression. We will clarify the influence of MEG3 on AML tumor growth by gain(overexpression) of function, hoping to further reveal the pathogenesis of AML molecular mechanism, and provide new targets for the diagnosis of AML. Methods: 1.The different expression level of long noncoding RNA MEG3 in AML cell lines was detected by real-time quantification PCR. 2. Established the MEG3 lentivirus vector.3. Generation of stable MEG3 overexpression cell pools in U937 cells and real-time quantification PCR was used to detect the e xpression levels of MEG3. 4. The effect of MEG3 on proliferation was evaluated by MTT. 5. The effect of MEG3 on cell apoptosis and cell cycle was detected by Flow-cytometric analysis.6. The mRNA levels of MDM2、RB and DNMT3 A were determined by RT-qPCR. Protein levels of them were determined by western blot analysis. Results: 1.The lower expression of MEG3 in AML cell lines was detected by RT-qPCR. 2.The stable MEG3 overexpression cell pools in U937 cells was successful established. 3.After transfection 48 h, MTT assay revealed that cell growth was significantly decreased in AML cell lines transfected with MEG3 compared with controls.4.After transfection 48 h, using flow cytometer to detect cell apoptosis and cycle, found that compared with the control group, treatment group increased cell apoptosis, stagnation of cells in G0 / G1 phase, and the S phase decreased obviously.5. The results of RT-qPCR showed that the expression of DNMT3 A was significantly decreased. Western blot analysis showed that the expression of Rb was significantly increased and the expression of MDM2 and DNMT3 A was down regulated in U937 cells transfected with MEG3 compared with control. Conclusions: Our findings suggest that MEG3 is significantly down regulated in AML cell lines. Its overexpression may results in the inhibition of cell proliferation, promotion cell apoptosis and regulating the function of the cell cycle, partially via the decreased expression of DNMT3 A.