ABSTRACT
AIMS: Osteosarcoma (OS) is an extremely malignant bone cancer with high incidence and rapid progression. This study aims to investigate the role and underlying mechanisms of MALAT1 and miR-485-3p in OS. MATERIALS AND METHODS: qRT-PCR and Western blotting were utilized to measure the levels of miR-485-3p, MALAT1, c-MET, AKT3, p-mTOR, mTOR, glycolysis-related proteins or migration-related proteins. Colony formation and transwell assay were used to test the roles of miR-485-3p, MALAT1, c-MET and AKT3 in cancer cell proliferation, migration and invasion. Dual luciferase assay was used to validate the interactions of miR-485-3p/c-MET, miR-485-3p/AKT3, and MALAT1/miR-485-3p. Glucose uptake assay and measurement of lactate production were employed to determine the glycolysis process. Mouse tumour xenograft model was used to determine the effect of shMALAT1 and miR-485-3p mimics on tumour growth and metastasis in vivo. KEY FINDINGS: miR-485-3p was decreased while c-MET, AKT3, and MALAT1 were increased in human OS tissues and cells. miR-485-3p bound directly to c-MET and AKT3 mRNAs and repressed OS cell glycolysis, proliferation, migration, and invasion through decreasing glycolysis-related proteins and migration-related proteins via inhibiting c-MET and AKT3/mTOR pathway. In addition, MALAT1 interacted with miR-485-3p and disinhibited c-MET and AKT3/mTOR signalling. Knockdown MALAT1 or overexpression of miR-485-3p restrained OS tumour growth and lung metastasis in vivo. SIGNIFICANCE: miR-485-3p suppresses OS glycolysis, proliferation, and metastasis via inhibiting c-MET and AKT3/mTOR signalling and MALAT1 acts as a sponge of miR-485-3p. MALAT1 and miR-485-3p may be the key regulators in OS progression, and potential molecular targets for future OS therapy.
Subject(s)
Bone Neoplasms/pathology , MicroRNAs/genetics , Osteosarcoma/pathology , Proto-Oncogene Proteins c-met/genetics , RNA, Long Noncoding/genetics , Animals , Bone Neoplasms/genetics , Bone Neoplasms/metabolism , Cell Line, Tumor , Cell Movement/genetics , Gene Expression Regulation, Neoplastic , Gene Knockdown Techniques , Glycolysis/genetics , Humans , Male , Mice, Inbred BALB C , Osteosarcoma/genetics , Osteosarcoma/metabolism , Proto-Oncogene Proteins c-akt/genetics , Proto-Oncogene Proteins c-akt/metabolism , Proto-Oncogene Proteins c-met/metabolism , TOR Serine-Threonine Kinases/genetics , TOR Serine-Threonine Kinases/metabolism , Xenograft Model Antitumor AssaysABSTRACT
DNA (cytosine-5)-methyltransferase 3 alpha (DNMT3A) mutations were widely believed to be independently associated with inferior prognosis in acute myeloid leukemia (AML) patients. As dominant missense alterations in DNMT3A mutations, R882 mutations cause the focal hypomethylation phenotype. However, there remains debate on the influence of R882 mutations on AML prognosis. Thus, this meta-analysis aimed at further illustrating the prognostic power of DNMT3A R882 mutations in AML patients.Eligible studies were identified from 5 databases containing PubMed, Embase, Web of Science, Clinical Trials, and the Cochrane Library (up to October 25, 2015). Effects (hazard ratios [HRs] with 95% confidence interval [CI]) of relapse-free survival (RFS) and overall survival (OS) were pooled to estimate the prognostic power of mutant DNMT3A R882 in overall patients and subgroups of AML patients.Eight competent studies with 4474 AML patients including 694 with DNMT3A R882 mutations were included. AML patients with DNMT3A R882 mutations showed significant shorter RFS (HRâ=â1.40, 95% CIâ=â1.24-1.59, Pâ<â0.001) and OS (HRâ=â1.47, 95% CIâ=â1.17-1.86, Pâ=â0.001) in the overall population. DNMT3A R882 mutations predicted worse RFS and OS among the subgroups of patients under age 60 (RFS: HRâ=â1.44, 95% CIâ=â1.25-1.66, Pâ<â0.001; OS: HRâ=â1.48, 95% CIâ=â1.15-1.90, Pâ=â0.002), over age 60 (RFS: HRâ=â2.03, 95% CIâ=â1.40-2.93, Pâ<â0.001; OS: HRâ=â1.85, 95% CIâ=â1.36-2.53, Pâ<â0.001), cytogenetically normal (CN)-AML (RFS: HRâ=â1.52, 95% CIâ=â1.26-1.83, Pâ<â0.001; OS: HRâ=â1.67, 95% CIâ=â1.16-2.41, Pâ=â0.006), and non-CN-AML (RFS: HRâ=â1.96, 95% CIâ=â1.20-3.21, Pâ=â0.006; OS: HRâ=â2.51, 95% CIâ=â1.52-4.15, Pâ=â0.0038).DNMT3A R882 mutations possessed significant unfavorable prognostic influence on RFS and OS in AML patients.
Subject(s)
DNA (Cytosine-5-)-Methyltransferases/genetics , Leukemia, Myeloid, Acute , DNA Methyltransferase 3A , Humans , Leukemia, Myeloid, Acute/diagnosis , Leukemia, Myeloid, Acute/genetics , Prognosis , Survival AnalysisABSTRACT
HOX genes are transcription factors that control morphogenesis, organogenesis and differentiation. Increasing evidence suggests that HOX genes play a role in hepatocellular carcinoma (HCC) progression; however few studies have defined the functional roles and mechanisms of action. In the present study, we used siRNA and forced-expression in multiple cell lines to define the role of HOXA7 in the regulation of proliferation of HCC in vitro and in vivo. Knockdown of endogenous HOXA7 decreased the proliferation of HepG2 and QGY-7703 cells. These changes were not associated with significant changes in cyclin D1 and CDK4. However, downregulation of HOXA7 significantly reduced cyclin E1 and CDK2 protein levels. Conversely, overexpression of HOXA7 in QSG-7701 cells stimulated proliferation and increased cyclin E1 and CDK2 protein levels. Our results confirmed that HOXA7 promoted cell proliferation, and these changes were mediated by cyclin E1/CDK2. These observations contribute to our understanding of the important roles of HOXA7 in HCC development and progression and HOXA7 could be a promising molecular target for the development of new diagnostic and therapeutic strategies for HCC.
