RNAi-mediated knockdown of cyclooxygenase2 inhibits the growth, invasion and migration of SaOS2 human osteosarcoma cells: a case control study

<p>Abstract</p> <p>Background</p> <p>Cyclooxygenase2 (COX-2), one isoform of cyclooxygenase proinflammatory enzymes, is responsible for tumor development, invasion and metastasis. Due to its role and frequent overexpression in a variety of human malignancies, including osteosarcoma, COX-2 has received considerable attention. However, the function of COX-2 in the pathogenesis of cancer is not well understood. We examined the role of COX-2 in osteosarcoma.</p> <p>Methods</p> <p>We employed lentivirus mediated-RNA interference technology to knockdown endogenous gene COX-2 expression in human osteosarcoma cells (SaOS2) and analyzed the phenotypical changes. The effect of COX-2 treatment on the proliferation, cell cycle, invasion and migration of the SaOS2 cells were assessed using the MTT, flow cytometry, invasion and migration assays, respectively. COX-2, vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), basic fibroblast growth factor (bFGF) mRNA and protein expression were detected by RT-PCR and western blotting.</p> <p>Results</p> <p>Our results indicate that a decrease of COX-2 expression in human osteosarcoma cells significantly inhibited the growth, decreased the invasion and migration ability of SaOS2 cells. In addition, it also reduced VEGF, EGF and bFGF mRNA and protein expression.</p> <p>Conclusions</p> <p>The COX-2 signaling pathway may provide a novel therapeutic target for the treatment of human osteosarcoma.</p

miR‑29b promotes the osteogenic differentiation of mesenchymal stem cells derived from human adipose&nbsp;tissue via the PTEN/AKT/β‑catenin signaling pathway.

Accumulating evidence has documented that microRNAs (miRNAs or miRs) function as important post‑transcriptional regulators of the differentiation of mesenchymal stem cells (MSCs), including human adipose‑derived mesenchymal stem cells (hADSCs); however, their roles in hADSC osteogenic differentiation require further investigation. The present study aimed to investigate the role of miRNAs in the osteogenic differentiation of hADSCs and to elucidate the underlying molecular mechanisms. Using an miRNA microarray, it was found that 24 miRNAs were upregulated and 14 miRNAs were downregulated compared with the undifferentiated cells, and miR‑29b‑3p (miR‑29b) was selected for further experiments. Functional experiments revealed that the upregulation of miR‑29b by agomir‑29b significantly enhanced alkaline phosphatase (ALP) activity and the mineralization of extracellular matrix (ECM), and led to an increase in the mRNA and protein levels of osteogenic marker genes, including runt‑related transcription factor 2 (Runx2), osteopontin (OPN), osteocalcin (OCN) and bone sialoprotein (BSP), whereas the knockdown of miR‑29b suppressed these processes. In addition, phosphatase and tensin homolog (PTEN), a negative regulator of the AKT/β‑catenin pathway, was identified as a direct target of miR‑29b in the hADSCs. Moreover, it was observed that the overexpression of miR‑29b activated the AKT/β‑catenin signaling pathway by inhibiting PTEN expression in the hADSCs. Most importantly, it was also found that the overexpression of PTEN reversed the promoting effects of miR‑29b on osteogenic differentiation. On the whole, these findings suggest that miR‑29b promotes the osteogenic differentiation of hADSCs by modulating the PTEN/AKT/β‑catenin signaling pathway. Thus, this miRNA may be a promising target for the active modulation of hADSC‑derived osteogenesis

Investigation of candidate genes for osteoarthritis based on gene expression profiles.

ObjectiveTo explore the mechanism of osteoarthritis (OA) and provide valid biological information for further investigation.MethodsGene expression profile of GSE46750 was downloaded from Gene Expression Omnibus database. The Linear Models for Microarray Data (limma) package (Bioconductor project, http://www.bioconductor.org/packages/release/bioc/html/limma.html) was used to identify differentially expressed genes (DEGs) in inflamed OA samples. Gene Ontology function enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways enrichment analysis of DEGs were performed based on Database for Annotation, Visualization and Integrated Discovery data, and protein-protein interaction (PPI) network was constructed based on the Search Tool for the Retrieval of Interacting Genes/Proteins database. Regulatory network was screened based on Encyclopedia of DNA Elements. Molecular Complex Detection was used for sub-network screening. Two sub-networks with highest node degree were integrated with transcriptional regulatory network and KEGG functional enrichment analysis was processed for 2 modules.ResultsIn total, 401 up- and 196 down-regulated DEGs were obtained. Up-regulated DEGs were involved in inflammatory response, while down-regulated DEGs were involved in cell cycle. PPI network with 2392 protein interactions was constructed. Moreover, 10 genes including Interleukin 6 (IL6) and Aurora B kinase (AURKB) were found to be outstanding in PPI network. There are 214 up- and 8 down-regulated transcription factor (TF)-target pairs in the TF regulatory network. Module 1 had TFs including SPI1, PRDM1, and FOS, while module 2 contained FOSL1. The nodes in module 1 were enriched in chemokine signaling pathway, while the nodes in module 2 were mainly enriched in cell cycle.ConclusionThe screened DEGs including IL6, AGT, and AURKB might be potential biomarkers for gene therapy for OA by being regulated by TFs such as FOS and SPI1, and participating in the cell cycle and cytokine-cytokine receptor interaction pathway

Investigation of candidate genes for osteoarthritis based on gene expression profiles

AbstractObjectiveTo explore the mechanism of osteoarthritis (OA) and provide valid biological information for further investigation.MethodsGene expression profile of GSE46750 was downloaded from Gene Expression Omnibus database. The Linear Models for Microarray Data (limma) package (Bioconductor project, http://www.bioconductor.org/packages/release/bioc/html/limma.html) was used to identify differentially expressed genes (DEGs) in inflamed OA samples. Gene Ontology function enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways enrichment analysis of DEGs were performed based on Database for Annotation, Visualization and Integrated Discovery data, and protein–protein interaction (PPI) network was constructed based on the Search Tool for the Retrieval of Interacting Genes/Proteins database. Regulatory network was screened based on Encyclopedia of DNA Elements. Molecular Complex Detection was used for sub-network screening. Two sub-networks with highest node degree were integrated with transcriptional regulatory network and KEGG functional enrichment analysis was processed for 2 modules.ResultsIn total, 401 up- and 196 down-regulated DEGs were obtained. Up-regulated DEGs were involved in inflammatory response, while down-regulated DEGs were involved in cell cycle. PPI network with 2392 protein interactions was constructed. Moreover, 10 genes including Interleukin 6 (IL6) and Aurora B kinase (AURKB) were found to be outstanding in PPI network. There are 214 up- and 8 down-regulated transcription factor (TF)-target pairs in the TF regulatory network. Module 1 had TFs including SPI1, PRDM1, and FOS, while module 2 contained FOSL1. The nodes in module 1 were enriched in chemokine signaling pathway, while the nodes in module 2 were mainly enriched in cell cycle.ConclusionThe screened DEGs including IL6, AGT, and AURKB might be potential biomarkers for gene therapy for OA by being regulated by TFs such as FOS and SPI1, and participating in the cell cycle and cytokine–cytokine receptor interaction pathway