Yuebai Li

miR-27a attenuates adipogenesis and promotes osteogenesis in steroid-induced rat BMSCs by targeting PPARγ and GREM1

The imbalance between adipogenic and osteogenic differentiation in bone marrow mesenchymal stem cells (BMSCs) plays a significant role in the pathogenesis of steroid-induced osteonecrosis of the femoral head (ONFH). Several microRNAs (miRNAs) are involved in regulating adipogenesis and osteogenesis. In this study, we established a steroid-induced ONFH rat model to identify the potential relevant miRNAs. We identified 9 up-regulated and 28 down-regulated miRNAs in the ONFH rat model. Of these, miR-27a was down-regulated and negatively correlated with peroxisome proliferator-activated receptor gamma (PPARγ) and gremlin 1 (GREM1) expression. Further studies confirmed that PPARγ and GREM1 were direct targets of miRNA-27a. Additionally, adipogenic differentiation was enhanced by miR-27a down-regulation, whereas miRNA-27a up-regulation attenuated adipogenesis and promoted osteogenesis in steroid-induced rat BMSCs. Moreover, miRNA-27a up-regulation had a stronger effect on adipogenic and osteogenic differentiation in steroid-induced rat BMSCs than si-PPARγ and si-GREM1. In conclusion, we identified 37 differentially expressed miRNAs in the steroid-induced ONFH model, of which miR-27a was down-regulated. Our results showed that miR-27a up-regulation could inhibit adipogenesis and promote osteogenesis by directly targeting PPARγ and GREM1. Thus, miR-27a is likely a key regulator of adipogenesis in steroid-induced BMSCs and a potential therapeutic target for ONFH treatment.

Upregulation of miR-192 inhibits cell growth and invasion and induces cell apoptosis by targeting TCF7 in human osteosarcoma

MicroRNAs (miRNAs) can function as oncogenes or tumor suppressor genes and are involved in multiple processes in cancer development and progression. For example, miR-192 is dysregulated in multiple human cancers, including osteosarcoma (OS). However, the pathophysiological role of miR-192 and its relevance to OS cell growth and invasion has not yet been clarified. This study aimed to investigate the expression of miR-192 in OS and elucidate the molecular mechanisms by which miR-192 acts as a tumor suppressor in this disease. The qRT-PCR data identified significant down-regulation of miR-192 in 20 OS tissue samples and two OS cell lines when compared with adjacent normal tissues and a human osteoblast cell line, respectively. Furthermore, Western blot analysis revealed overexpression of T cell-specific transcription factor (TCF) 7 protein in tumor tissues compared with matched adjacent normal tissues. Further in vitro studies demonstrated that enforced expression of miR-192 inhibited U2OS and MG63 cell proliferation, invasion, and migration and induced apoptosis. Finally, Western blot and Luciferase assays identified TCF7 as a target of miR-192. Collectively, these findings suggest an important role for miR-192 in regulating the proliferation, migration, invasion, and apoptosis of OS cells through the regulation of TCF7.

Long non-coding RNA TCONS_00041960 enhances osteogenesis and inhibits adipogenesis of rat bone marrow mesenchymal stem cell by targeting miR-204-5p and miR-125a-3p

A growing number of long non‐coding RNAs (lncRNAs) have been found to be involved in diverse biological processes such as cell cycle regulation, embryonic development, and cell differentiation. However, limited knowledge is available concerning the underlying mechanisms of lncRNA functions. In this study, we found down‐regulation of TCONS_00041960 during adipogenic and osteogenic differentiation of glucocorticoid‐treated bone marrow mesenchymal stem cells (BMSCs). Furthermore, up‐regulation of TCONS_00041960 promoted expression of osteogenic genes Runx2, osterix, and osteocalcin, and anti‐adipogenic gene glucocorticoid‐induced leucine zipper (GILZ). Conversely, expression of adipocyte‐specific markers was decreased in the presence of over‐expressed TCONS_00041960. Mechanistically, we determined that TCONS_00041960 as a competing endogenous RNA interacted with miR‐204‐5p and miR‐125a‐3p to regulate Runx2 and GILZ, respectively. Overall, we identified a new TCONS_00041960‐miR‐204‐5p/miR‐125a‐3p‐Runx2/GILZ axis involved in regulation of adipogenic and osteogenic differentiation of glucocorticoid‐treated BMSCs.

MicroRNA-192 inhibits the proliferation, migration and invasion of osteosarcoma cells and promotes apoptosis by targeting matrix metalloproteinase-11

MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression during stem cell growth, proliferation and differentiation. miRNAs are also involved in the development and progression of a number of cancer types, including osteosarcoma (OS). miR-192 is significantly downregulated in various tumors, including lung, bladder and rectal cancer. miR-192 expression is associated with the migration and invasion of OS cells. However, the expression of miR-192 and its effects on the development of OS have not been reported. In the present study, the involvement of miR-192 and its molecular mechanisms in the development of OS was investigated. The results indicate that miR-192 expression was significantly downregulated in OS tissues compared with non-tumor tissues (P<0.05). Next, a miR-192 agomir was transfected into the OS cell line MG-63 to upregulate miR-192. The effects of miR-192 overexpression were then investigated by examining cell proliferation, apoptosis, migration and invasion. Matrix metalloproteinase (MMP)-11 belongs to a family of nine or more highly homologous Zn2+-endopeptidases. It was demonstrated that the mRNA and protein expression of MMP-11 were upregulated in OS tissues compared with non-tumor tissues (P<0.05). MMP-11 was predicted by TargetScan and miRanda as a miR-192 target, which was confirmed by western blotting and dual-luciferase assays. Finally, it was demonstrated that the overexpression of miR-192 was able to downregulate MMP-11 expression and reduce proliferation, migration and invasion, and promote apoptosis in OS cells. Together, these data indicate that miR-192 may be a tumor suppressor that inhibits the progression and invasion of OS by targeting MMP-11. Therefore, miR-192 may be useful for the diagnosis and treatment of OS.

Downregulation of lncRNA ANRIL suppresses growth and metastasis in human osteosarcoma cells

Background This study was designed to research the potential function of lncRNA ANRIL in osteosarcoma (OS). Materials and methods Quantitative real-time PCR, cell counting kit-8, wound healing assay, Transwell assay, flow cytometric analysis, caspase activity analysis, and Western blot were carried out. Results ANRIL was remarkably upregulated in human OS tissues and cells, and knockdown of ANRIL significantly suppressed MG63 cell proliferation, migration, and invasion and promoted apoptosis. Moreover, our mechanistic research findings verified that ANRIL-influenced growth and apoptosis may be partly through regulation of caspase-3 and Bcl-2. Migration and invasion were influenced via ANRIL-mediated regulation of MTA1, TIMP-2, and E-cadherin. Conclusion Our finding demonstrates that ANRIL plays vital roles in OS growth and metastasis.

Long noncoding RNA APTR contributes to osteosarcoma progression through repression of miR-132-3p and upregulation of yes-associated protein 1: GUAN et al.

A growing amount of evidence has shown that long noncoding RNAs (lncRNAs) play crucial roles in osteosarcoma (OS). However, little knowledge is available about the functional roles and molecular mechanisms of lncRNA Alu‐mediated p21 transcriptional regulator (APTR) in OS. Herein, APTR expression was demonstrated to be significantly upregulated in OS tumor tissues and four OS cell lines (including MG63, 143B, Saos‐2, and HOS) compared with the adjacent tissues and human osteoblast cell line hFOB1.19, respectively. We confirmed miR‐132‐3p to be a target for APTR, and its expression was demonstrated to be inhibited by APTR. In functional terms, knockdown of APTR and overexpression of miR‐132‐3p both, remarkably repressed human OS cell proliferation, invasion and migration, and induced apoptosis. Also, Yes‐associated protein 1 (YAP1) was determined as an inhibitory target of miR‐132‐3p. Moreover, our findings demonstrated that the repression of YAP1 protein expression and the suppression of Ki‐67, MMP9, and Bcl2 expression induced by APTR knockdown required increased miR‐132‐3p. Thus, APTR contributed to OS progression through repression of miR‐132‐3p and upregulation of YAP1 expression. Therefore, we have uncovered a novel regulatory mechanism by which the APTR/miR‐132‐3p/YAP1 axis can regulate OS progression.

miR-17-5p promotes proliferation and epithelial-mesenchymal transition in human osteosarcoma cells by targeting SRC kinase signaling inhibitor 1: ZHAO et al.

MicroRNA‐17‐5p (miR‐17‐5p) and epithelial‐mesenchymal transition (EMT) have been reported to participate in the development and progression of multiple cancers. However, the relationship between the miR‐17‐5p and EMT in osteosarcoma (OS) is still poorly understood. This study was to investigate the effects of the miR‐17‐5p and its potential mechanism in regulating proliferation, apoptosis, and EMT of human OS. Quantitative real‐time PCR was used to detect the miR‐17‐5p and SRC kinase signaling inhibitor 1 (SRCIN1) messenger RNA expression in OS specimens and cell lines. After transfection with miR‐17‐5p inhibitors, proliferation, apoptosis, migration, and invasion of OS cells were assessed by using the Cell Counting Kit‐8, the annexin V‐FITC apoptosis, wound‐healing, and transwell assays. The SRCIN1 was validated as a target of the miR‐17‐5p through bioinformatics algorithms and luciferase reporter assay. Moreover, the expression of EMT markers, E‐cadherin, N‐cadherin, and Snail was identified by the Western blot analysis. MiR‐17‐5p was significantly upregulated in OS tumor samples and cell lines. It inhibited proliferation and EMT, and promoted apoptosis in OS. The SRCIN1 was identified as a direct target of the miR‐17‐5p. Silenced miR‐17‐5p could change the expression of EMT markers, such as upregulating the expression of E‐cadherin, and downregulating the expression of N‐cadherin and Snail through targeting the antioncogenic SRCIN1. These findings suggest that the miR‐17‐5p promotes cell proliferation, and EMT in human OS by directly targeting the SRCIN1, and reveal a branch of the miR‐17‐5p/SRCIN1/EMT signaling pathway involved in the progression of OS.