Long non-coding RNA MIR17HG sponges microRNA-21 to upregulate PTEN and regulate homoharringtonine-based chemoresistance of acute myeloid leukemia cells.

Long non-coding (lnc)RNA MIR17HG has been identified as a oncogene whose roles in acute myeloid leukemia (AML) remain unclear. The present study aimed to investigate the role of lncRNA MIR17HG in AML. Differential expression of MIR17HG in AML was determined by reverse transcription-quantitative PCR. Overexpression assays and dual luciferase reporter assays were performed to determine the relationship between MIR17HG and microRNA (miR)-21, and apoptosis was analyzed by using an apoptosis assay. The results showed that the expression of MIR17HG was decreased in AML, which was further decreased following homoharringtonine (HHT)-based chemotherapy. Bioinformatics analysis predicted that miR-21 could bind with MIR17HG. However, miR-21 overexpression had no effect on the expression level of MIR17HG. Dual luciferase reporter assays were performed to verify the direct interaction between miR-21 and MIR17HG. In addition, overexpression of MIR17HG and miR-21 in AML cell lines up- and downregulated the expression level of PTEN, respectively. Furthermore, cell apoptosis showed that MIR17HG and PTEN overexpression enhanced cell apoptosis following cell treatment with HTT. However, miR-21 overexpression exerted the opposite effect, since it reversed the effects of MIR17HG and PTEN overexpression in AML cell apoptosis. In conclusion, the current study suggested that MIR17HG could regulate the miR-21/PTEN axis to modulate the chemoresistance of AML cells.

Downregulated miR-217 expression predicts a poor outcome in acute myeloid leukemia.

BACKGROUND: Circulating microRNAs (miRNAs) play an essential role in the development and progression of acute myeloid leukemia (AML). However, the clinical value of serum miR-217 in AML remained poorly known. OBJECTIVE: This study aimed to explore the clinical significance of serum miR-217 in AML. METHODS: Quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) was performed to detect miR-217 levels in the blood samples obtained from 89 AML patients and 60 healthy controls. RESULTS: The results showed that miR-217 expression was significantly decreased in AML patients compared to controls. Likewise, serum miR-217 levels were greatly downregulated in the AML patients with poor risk cytogenetic. ROC analysis demonstrated that serum miR-217 could effectively differentiate AML patients from normal controls. Also, miR-217 expression was markedly increased in patients achieving complete remission after their treatment. In addition, low miR-217 expression was associated with aggressive clinical features. Moreover, Kaplan-Meier analysis showed that AML patients with low miR-217 expression tended to have shorter overall survival and disease free survival. In the multivariate analysis stratified for prognostic parameters, miR-217 was proved to be an independent prognostic indicator. CONCLUSIONS: Collectively, miR-217 was identified as an independent marker for the diagnosis and prognosis of AML.

[Treatment of leukemia by allogeneic peripheral blood stem cell transplantation from sibling donors].

This study was aimed to observe the efficacy and side effects of allogeneic peripheral blood stem cell transplantation (Allo-PBSCT) in patients with leukemia. The donors were siblings matched with t HLA-A, B, DR loci of recipient. After mobilization with 250 microg/day rhG-CSF for 5 days, peripheral blood stem cells were collected 1 to 2 times. 4 patients with leukemia received 6.78 x 10(8)/kg +/- 1.96 x 10(8)/kg (5 x 10(8)/kg-8.67 x 10(8)/kg) peripheral blood mononuclear cells, which contained 15.02 x 10(6)/kg +/- 8.93 x 10(6)/kg (5.3 x 10(6)/kg-24.23 x 10(6)/kg) CD34(+) cells after modified Bu/Cy conditioning regimen and MTX + CsA + MMF were given for prophylaxis of aGVHD. The results showed that the leukocyte was reduced to the lowest at pretransplantation 2 days-posttransplantation 2 days. Neutrophil amount >0.5 x 10(9)/L was found at 11 - 17 day after transplantation, platelet >50 x 10(9)/L-at 11 - 55 days after transplantation. Out of 4 patients, aGVHD, cGVHD and infection took place in 2,2 and 2 cases, respectively. Bone marrow displayed hematopoietic recovery at 28 day after transplantation, examination of STR in DNA revealed proliferation of donor cells in patients. In conclusion, Allo-PBSCT in combination with modified Bu/Cy conditioning regimen and MTX + CsA + MMF prophylaxis of aGVHD is safety and reliable for treatment of leukemia.