BackgroundMicroRNAs (miR, miRNAs) play pivotal roles in numerous physiological and pathophysiological contexts. We investigated whether miR-362-5p act as an oncogene in chronic myeloid leukaemia (CML) and aimed to understand its potential underlying mechanisms.MethodsWe compared the miR-362-5p expression levels between CML and non-CML cell lines, and between fresh blood samples from CML patients and normal healthy controls using quantitative real-time PCR (qPCR). Cell counting kit-8 (CCK-8) and Annexin V-FITC/PI analyses were used to measure the effects of miR-362-5p on proliferation and apoptosis, and Transwell assays were used to evaluate migration and invasion. A xenograft model was used to examine in vivo tumourigenicity. The potential target of miR-362-5p was confirmed by a luciferase reporter assay, qPCR and western blotting. Involvement of the JNK1/2 and P38 pathways was investigated by western blotting.ResultsmiR-362-5p was up-regulated in CML cell lines and fresh blood samples from CML patients, and was associated with Growth arrest and DNA damage-inducible (GADD)45α down-regulation. Inhibition of miR-362-5p simultaneously repressed tumour growth and up-regulated GADD45α expression in a xenograft model. Consistently, the knockdown of GADD45α expression partially neutralized the effects of miR-362-5p inhibition. Furthermore study suggested that GADD45α mediated downstream the effects of miR-362-5p, which might indirectly regulates the activation of the JNK1/2 and P38 signalling pathways.ConclusionmiR-362-5p acts as an oncomiR that down-regulates GADD45α, which consequently activates the JNK1/2 and P38 signalling. This finding provides novel insights into CML leukaemogenesis and may help identify new diagnostic and therapeutic targets.Electronic supplementary materialThe online version of this article (doi:10.1186/s12943-015-0465-3) contains supplementary material, which is available to authorized users.

Hepatocellular Carcinoma (HCC) is a malignant tumor with high rate of relapse and metastasis. Ethanol is a well‐known risk factor for HCC; it promotes the progression and aggressiveness of HCC. However, the underlying mechanism remains unclear. In clinic studies, we showed that alcohol consumption is positively correlated with TNM stage and vessel invasion; HCC patients with chronic drinking history had faster progression rate and poorer prognosis compared to non‐drinkers. In experimental models, ethanol exposure enhanced the metastasis, and invasion of HCC cells. Ethanol exposure increased cancer stem cells (CSC) population and enhanced stemness of HCC cells in vitro and in vivo. Mechanically, we found that ethanol exposure induced epithelial to mesenchymal transition (EMT) through activating Wnt/β‐catenin signaling pathway in HCC cells. We further demonstrated that β‐catenin siRNA or salinomycin (an inhibitor of Wnt/β‐catenin pathway) partially rescued ethanol‐induced EMT. In conclusion, this study suggested that ethanol exposure promotes the metastasis and stemness of HCC cells by inducing EMT.

Hepatocellular Carcinoma (HCC) patients usually have a high rate of relapse and metastasis. Alcohol, a risk factor for HCC, promotes the aggressiveness of HCC. However, the basic mechanism is still unclear. We used HCC cells and an orthotopic liver tumor model of HCC-LM3 cells for BALB/C nude mice to study the mechanism of alcohol-induced HCC progression. We showed that chronic alcohol exposure promoted HCC cells metastasis and pulmonary nodules formation. First, we identified miR-22-3p as an oncogene in HCC, which promoted HCC cells stemness, tumor growth, and metastasis. Further, we found that miR-22-3p directly targeted TET2 in HCC. TET2, a dioxygenase involved in cytosine demethylation, has pleiotropic roles in hematopoietic stem cells self-renewal. In clinic HCC specimen, TET2 expression was not only decreased by alcohol consumption, but also inversely correlated with miR-22-3p levels. Then, we demonstrated that TET2 depletion promoted HCC cells stemness, tumor growth and metastasis. Furthermore, we identified that β -catenin was an upstream activator of miR-22-3p. In conclusion, this study suggests that chronic alcohol exposure promotes HCC progression and β -catenin/miR-22-3p/TET2 regulatory axis plays an important role in alcohol-promoted HCC malignancy.

This article has been retracted. Please see the Retraction Notice for more detail: https://doi.org/10.1186/s12943-015-0465-3.