Preliminary study of role of post-transcription regulation on SH2 domain-containing inositol 5'-phosphatase 1 gene expression by miR-155 in the pathogenesis of acute myeloid leukemia / 白血病·淋巴瘤

ABSTRACT

Objective To investigate the role of microRNA-155 (miR-155) on post-transcription regulation of SH2 domain-containing inositol 5'-phosphatase 1 (SHIP1) gene expression in the pathogenesis of acute myeloid leukemia (AML).Methods Quantitative real-time polymerase chain reaction (RT-PCR) was performed to detect the expression of miR-155 and SHIP1 mRNA in the AML patients and controls.miR-155 mimics was transfected into U937cells (U937m) by using X-treme GENE siRNA transfection reagent.Cells without transfection (U937c) and cells with negative transfection (U937mc) were used as controls.RT-PCR was performed to detect the expression of miR-155 and SHIP1 mRNA in these cells.The expression of SHIP1,TAKT and pAKT were detected by Western blot in U937 cells.Apoptosis was studied by flow cytometry (FCM).Results The average level of SHIP1 protein content in 15 samples of patients with AML-M4 or AML-M5 from 30 AML patients was significantly lower compared with that of patients with the other types of AML,and the levels of miR-155 were significantly higher in the same group of patients (P ＜ 0.05).Significantly decreased levels of SHIP1 protein were found in U937m cells compared that of U937c and U937mc (P ＜ 0.05).Significantly decreased rate of apoptosis was observed in U937m cells compared with that of U937mc and U937c.U937m cells also exhibited no alteration in total AKT content,while increased p-AKT levels were found (P＜ 0.05).Conclusion SHIP1 was also a primary target of miR-155 in AML.Overexpression of miR-155 could activate PI3K-AKT pathway to depressing SHIP1 and decrease the apoptosis rate of AML cells.