PODN is a prognostic biomarker and correlated with immune infiltrates in osteosarcoma.

BACKGROUND: Osteosarcoma was the most common primary bone malignancy in children and adolescents. It was imperative to identify effective prognostic biomarkers for this cancer. This study was aimed to identify potential crucial genes of osteosarcoma by integrated bioinformatics analysis. METHODS: Identification of differentially expressed genes from public data gene expression profiles (GSE42352), functional and pathway enrichment analysis, protein-protein interaction (PPI) network construction and module analysis, Cox regression and survival analysis was conducted. RESULTS: Totally 17 co-differential genes were found to be differentially expressed. These genes were enriched in biological processes, Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Set Enrichment Analysis (GSEA) pathway of inflammatory immune response. PPI network was constructed with 63 differentially expressed genes that co-existed between the test set and the validation set. The area under the receiver operating characteristic curve (AUC value) was 0.855, which indicated that the expression of PODN had a good diagnostic value for osteosarcoma. Furthermore, Cox regression and survival analysis revealed 5 genes were statistically significant. CONCLUSIONS: PODN was regarded as a potential biomarker for the diagnosis and prognosis of osteosarcoma, ACTA2, COL6A1, FAP, OLFML2B and COL6A3, can be used as potential prognostic indicators for osteosarcoma.

miR-143 is implicated in growth plate injury by targeting IHH in precartilaginous stem cells.

Precartilaginous stem cells (PCSCs) are able to initiate chondrocyte and bone development. The present study aimed to investigate the role of miR-143 and the underlying mechanisms involved in PCSC proliferation. In a rat growth plate injury model, tissue from the injury site was collected and the expression of miR-143 and its potential targets was determined. PCSCs were isolated from the rabbits' distal epiphyseal growth plate. Cell viability, DNA synthesis, and apoptosis were determined with MTT, BrdU, and flow cytometric analysis, respectively. Real time PCR and western blot were performed to detect the mRNA and protein expression of the indicated genes. Indian hedgehog (IHH) was identified as a target gene for miR-143 with luciferase reporter assay. Decreased expression of miR-143 and increased expression of IHH gene were observed in the growth plate after injury. miR-143 mimics decreased cell viability and DNA synthesis and promoted apoptosis of PCSCs. Conversely, siRNA-mediated inhibition of miR-143 led to increased growth and suppressed apoptosis of PCSCs. Transfection of miR-143 decreased luciferase activity of wild-type IHH but had no effect when the 3'-UTR of IHH was mutated. Furthermore, the effect of miR-143 overexpression was neutralized by overexpression of IHH. Our study showed that miR-143 is involved in growth plate behavior and regulates PCSC growth by targeting IHH, suggesting that miR-143 may serve as a novel target for PCSC-related diseases.

MiR-132/212 promotes the growth of precartilaginous stem cells (PCSCs) by regulating Ihh/PTHrP signaling pathway.

Precartilaginous stem cells (PCSCs) are adult stem cells that can initiate chondrocytes and bone development. In the present study, we explored whether miR-132/212 was involved in the proliferation of PCSCs via Hedgehog signaling pathway. PCSCs were isolated and purified with the fibroblast growth factor receptor-3 (FGFR-3) antibody. Cell viability, DNA synthesis and apoptosis were measured using MTT, BrdU and flow cytometric analysis. The mRNA and protein expression were detected by real-time PCR and Western blot, respectively. The target gene for miR-132/212 was validated by luciferase reporter assay. Results showed that transfection with miR-132/212 mimic significantly increased cell viability and DNA synthesis, and inhibited apoptosis of PCSCs. By contrast, miR-132/212 inhibitor could suppress growth and promote apoptosis of PCSCs. Luciferase reporter assays indicated that transfection of miR-132/212 led to a marked reduction of luciferase activity, but had no effect on PTCH1 3'-UTR mutated fragment, suggesting that Patched1 (PTCH1) is a target of miR-132/212. Furthermore, treatment with miR-132/212 mimics obviously increased the protein expression of Indian hedgehog (Ihh) and parathyroid hormone related protein (PTHrP), which was decreased after treatment with Hedgehog signaling inhibitor, cyclopamine. We also found that inhibition of Ihh/PTHrP signaling by cyclopamine significantly suppressed growth and DNA synthesis, and induced apoptosis in PCSCs. These findings demonstrate that miR-132/212 promotes growth and inhibits apoptosis in PCSCs by regulating PTCH1-mediated Ihh/PTHrP pathway, suggesting that miR-132/212 cluster might serve as a novel target for bone diseases.