The roles of oxidative stress on nuclear factor (NF)-κB activity and cardiomyocyte apoptosis during heart failure were examined using the antioxidant N-acetylcysteine (NAC). Heart failure was established in Japanese white rabbits with intravenous injections of doxorubicin, with ten rabbits serving as a control group. Of the rabbits with heart failure, 12 were not treated (HF group) and 13 received NAC (NAC group). Cardiac function was assessed using echocardiography and hemodynamic analysis. Myocardial cell apoptosis, apoptosis-related protein expression, NF-κBp65 expression and activity, total anti-oxidative capacity (tAOC), 8-iso-prostaglandin F2α (8-iso-PGF2α) expression and glutathione (GSH) expression levels were determined. In the HF group, reduced tAOC, GSH levels and Bcl-2/Bax ratios as well as increased 8-iso-PGF2α levels and apoptosis were observed (all P<0.05), which were effects that were attenuated by the treatment with NAC. NF-κBp65 and iNOS levels were significantly higher and the P-IκB-α levels were significantly lower in the HF group; expression of all three proteins returned to pre-HF levels following treatment with NAC. Myocardial cell apoptosis was positively correlated with left ventricular end-diastolic pressure (LVEDP), NF-κBp65 expression and 8-iso-PGF2α levels, but negatively correlated with the maximal and minimal rates of increase in left ventricular pressure (+dp/dtmax and −dp/dtmin, respectively) and the Bcl-2/Bax ratio (all P<0.001). The 8-iso-PGF2α levels were positively correlated with LVEDP and negatively correlated with +dp/dtmax and −dp/dtmin (all P<0.001). The present study demonstrated that NAC increased the antioxidant capacity, decreased the NF-κB activation and reduced myocardial cell apoptosis in an in vivo heart failure model.

MicroRNAs (miRNAs or miRs) are involved in the development and progression of numerous types of cancer however their role in osteosarcoma has not been fully clarified. The present study aimed to use high-throughput bioinformatics analysis as well as in vitro experiments to investigate the potential role of transcription factors, miRNAs and their targets in the progression of osteosarcoma. miRNA data and clinical information of osteosarcoma were obtained from Gene Expression Omnibus database to investigate differentially expressed miRNAs. The expression of miRNAs/mRNAs in osteosarcoma cell lines was detected via reverse transcription-quantitative (RT-qPCR). MTT and colony formation assay were used to determine cell proliferation ability and transwell assay was used to observe cell invasion and migration ability. A total of four prediction algorithms for miRNA-mRNA interactions were used to determine potential target genes of miR-487a. Predicted target genes were used to intersect with overlapped differentially expressed genes (DEGs) from GSE12865 and The Cancer Genome Atlas osteosarcoma datasets. Expression of NK3 homeobox 1 (NKX3-1) was analyzed by western blotting and RT-qPCR assay. Dual luciferase assay was conducted to verify whether NKX3-1 was a direct target of miR-487a. The regulatory association between Kruppel-like factor 5 (KLF5) and miR-487a was detected using chromatin immunoprecipitation assay. miR-487a was upregulated in osteosarcoma tissue (GSE65071 and GSE28423) and cell lines (HOS and MG63). miR-487a mimic promoted proliferation, migration and invasion of osteosarcoma cells. NKX3-1 was a direct target of miR-487a and transfection of NKX3-1 plasmid reversed the effect of miR-487a on proliferation, migration and invasion of osteosarcoma cells. KLF5 enhanced miR-487a expression by directly binding to its promoter region and miR-487a inhibitor reversed the effect of KLF5 on proliferation, migration and invasion of osteosarcoma cells. The present results indicated that KLF5/miR-487a signaling promoted invasion and metastasis of osteosarcoma cells via targeting NKX3-1.

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