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FK506 (also known as tacrolimus) is a potent immunosuppressive agent that is widely used in the treatment of graft-rejection and autoimmune diseases. FK506 has attracted additional attention owing to its potential role in osteogenic differentiation and bone formation. MicroRNAs (miRNAs) have been demonstrated to serve important roles in the regulation of osteogenic differentiation; however, identification of specific miRNAs and their roles in regulating FK506-induced osteogenic differentiation have been poorly examined. In the present study, osteodifferentiation of rat bone marrow stromal cells (BMSCs) was induced with varying concentrations of FK506 (5-5,000 nM) for 3, 7 and 14 days. Differentially expressed miRNAs were profiled using miRNA array, verified by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and subjected to gene ontology (GO) term and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Results from the present study identified a subset of miRNAs that were differentially expressed, of which five upregulated miRNAs (miR-106b-5p, miR-101b-3p, miR-193a-3p, miR-485-3p and miR-142-3p) and four downregulated miRNAs (miR-27a-3p, miR-207, miR-218a-2-3p and let-7a-5p) were confirmed by RT-qPCR. GO and KEGG analysis revealed that the predicted target genes of these miRNAs are involved in multiple biological processes and signaling pathways, including cell differentiation and the mitogen-activated protein kinase (MAPK) signaling pathway. Verification of the miRNA-target genes revealed that Smad5, Jagged 1 and MAPK9 were significantly upregulated, whereas Smad7, BMP and activin membrane-bound inhibitor, and dual-specificity phosphatase 2 were significantly downregulated during FK506-induced osteodifferentiation. The present study may provide an experimental basis for further research on miRNA functions during FK506-induced osteogenic differentiation in rat BMSCs. [ABSTRACT FROM AUTHOR]

Krüppel-like factor 7 (KLF7) is a member of the KLF family of zinc finger transcription factors, and was the first KLF cloned using complementary DNA and polymerase chain reaction (PCR) techniques with human vascular endothelial cells as a template. In addition, KLF7 is known as the ubiquitous Krüppel-like factor, as it is widely expressed in numerous human tissues at low levels. In the present study, the function of KLF7 in migration and epithelial-mesenchymal transition (EMT), which are associated with tumor progression, was investigated in human oral squamous cell carcinoma (OSCC) cells. Genes that were differentially expressed in normal vs. OSCC tissue were identified in the Gene Expression Omnibus database, which identified upregulation of KLF7 in OSCC. The expression and subcellular location of KLF7 was then analyzed using immunohistochemistry. KLF7 expression was measured in three OSCC cell lines, and the two cell lines with the highest (HN13) and lowest (CAL27) KLF7 expression were selected for further analysis. Subsequently, HN13 cells with reduced KLF7 expression (sh-HN13) and CAL27 cells overexpressing KLF7 (OE-CAL27) were constructed. Transwell migration and wound healing assays were then used to analyze the migration of the cells. In addition, mRNA and protein expression levels of the EMT markers E-cadherin, N-cadherin, vimentin and snail were detected using reverse transcription-quantitative PCR and western blotting. KLF7 overexpression in OSCC was validated using tissue immunohistochemistry, which identified moderate to high cytoplasmic staining of KLF7 in OSCC cells. KLF7 knockdown and overexpression altered the migration ability of sh-HN13 and OE-CAL27 cells, which decreased and increased significantly respectively. Expression of E-cadherin, N-cadherin, vimentin and snail was markedly altered in sh-HN13 and OE-CAL27 cells, indicating changes in EMT status. The results of the present study suggest that KLF7 overexpression changes the migratory behavior of OSCC cells, and induces EMT and lymph node metastasis through the expression of snail. [ABSTRACT FROM AUTHOR]

The aim of the present study was to investigate the role of sentrin/small ubiquitin-like modifier (SUMO)-specific protease 5 (SENP5) in oral squamous cell carcinoma (OSCC), as the overexpression of SENP5 has been observed in 31 OSCC tissue specimens. CAL-27 OSCC cells were used for in vitro measurements. The distribution of SENP5 was visualized using immunohistochemistry and H2O2-induced oxidative stress, and the effects of SENP-small interfering RNA on SENP5 were analyzed via western blotting. The apoptotic rates of the CAL-27 cells during oxidative stress and SENP5 silencing were estimated using flow-cytometry, and the mitochondrial structures were analyzed using a mitochondria tracker. The SENP5 protein was localized in the nuclei and cytosols of the CAL-27 cells, and incubation with 100 μm H2O2 for >1 h led to its stabilization. Incubation with H2O2 alone had no effect on the CAL-27 cells, however, a combination of H2O2 and SENP5 silencing led to enhanced apoptotic rates (P<0.001). Analysis of the mitochondrial structures revealed that H2O2 alone enhanced mitochondrial network formation, whereas the combination of H2O2 and SENP5 silencing led to mitochondrial fragmentation in the CAL-27 cells. The overexpression of SENP5 partly localized in the cytosol of the OSCC cells. Mild oxidative stress stabilized the SENP5 protein in the CAL-27 cells, and only the combination of SENP5 silencing and H2O2 application led to mitochondria fragmentation and a significant increase in cell apoptosis. Therefore, SENP5 protected the OSCC cells from oxidative stress-induced apoptosis. [ABSTRACT FROM AUTHOR]