Changes in microRNA expression in the MG-63 osteosarcoma cell line compared with osteoblasts

MicroRNA-143 expression inhibits the growth and the invasion of osteosarcoma

Background

Osteosarcoma (OS) is a common malignant tumor, which occurs in the metaphysis of the long diaphysis from mesenchymal tissue. Previous studies have indicated that expression of microRNA-143 (miR-143) could affect cancer cell proliferation, migration and invasion. The present research was performed to figure out whethermiR-143 expression inhibits the growth and the invasion of OS.

Methods

We conducted a literature search in the electronic databases of Medline, Embase, Web of Science, and the Cochrane Library, SinoMed, WanFang, China national knowledge infrastructure (CNKI) until January 2022. We used Review Manager 5.3 software to conduct our research.

Results

Twelve eligible articles were included, 5 articles were reported outcomes about mice, 11 articles were reported outcomes about human. The results of mice demonstrated that the miR-143 group had significantly better results in tumor volume, tumor weight and survival rate. The results of human demonstrated that the high level of miR-143 group had significantly better results in the 3-year, 4-year, and 5-year survival rate, lung metastasis and tumor grade.

Conclusions

MiR-143 has potentially important value in the treatment and prognosis of OS. However, more reliable animal and clinical trials are needed before miR-143 based therapies can be transferred from animal studies to human applications.

MicroRNA-9 as a paradoxical but critical regulator of cancer metastasis: Implications in personalized medicine

Metastasis, is a development of secondary tumor growths at a distance from the primary site, and closely related to poor prognosis and mortality. However, there is still no effective treatment for metastatic cancer. Therefore, there is an urgent need to find an effective therapy for cancer metastasis. Plenty of evidence indicates that miR-9 can function as a promoter or suppressor in cancer metastasis and coordinate multistep of metastatic process. In this review, we summarize the different roles of miR-9 with the corresponding molecular mechanisms in metastasis of twelve common cancers and the multiple mechanisms underlying miR-9-mediated regulation of metastasis, benefiting the further research of miR-9 and metastasis, and hoping to bridge it with clinical applications.

Circular RNA_0062582 promotes osteogenic differentiation of human bone marrow mesenchymal stem cells via regulation of microRNA-145/CBFB axis

Osteoporosis poses a threat to human health worldwide. To date, there have been few studies regarding targeted treatment of osteoporosis. We aimed to identify the possible molecular mechanism of circular RNA (circ)_0062582 in osteogenic differentiation, and the interactions among circ_0062582, microRNA-145 (miR-145) and core-binding factor subunit β (CBFB). The proliferation of human bone marrow mesenchymal stem cells (hBMSCs) was tested with a cell counting kit-8 assay. Circ_0062582, miR-145 and CBFB were overexpressed by transient transfection. Dual-luciferase reporter assay system was used to analyze the combination among circ_0062582, miR-145 and CBFB. Additionally, the levels of circ_0062582, miR-145, CBFB, osterix (OSX), osteocalcin (OCN) and collagen type 1 (COL1) were detected by means of RT-qPCR or western blot analysis. Alkaline phosphatase and Alizarin red stainings were performed to analyze the degree of osteogenic differentiation under the control of circ_0062582, miR-145 and CBFB. The results demonstrated that circ_0062582 level was notably elvated during osteogenic differentiation of hBMSCs. Circ_0062582 overexpression significantly promoted osteogenic differentiation and upregulated the levels of osteogenic differentiation-related proteins, including OSX, OCN and COL1. In addition, miR-145, which was identified as the target gene of circ_0062582, could specifically target CBFB 3′-UTR regions. Next, these changes caused by the overexpression of circ_0062582 were reversed following the addition of miR-145 mimic. Following overexpression of CBFB, osteogenic differentiation was increased. In summary, these results demonstrated that the role of circ_0062582 in osteoporosis is mediated through regulating the expression level of CBFB via miR-145.

Identification of osteosarcoma by microRNA-coupled nuclease digestion on interdigitated electrode sensor

Osteosarcoma is a type of tumor originating from the bone cells, most often from long bones. Children and adolescents are mainly affected by osteosarcoma. Identifying the condition with osteosarcoma is mandatory to provide proper treatment to the affected patients. This research work has introduced an identification of an osteosarcoma biomarker "miRNA-21" on the interdigitated electrochemical sensor by nuclease digestion. The target RNA sequence of miRNA-21 was hybridized to the capture DNA and placed on the sensing electrode surface with the aid of the biotin-streptavidin interaction. The unhybridized immobilized single-standard capture DNA was digested by S1-nuclease. The current response of the digestion level was considered as the duplex formation between the target and capture DNA. Using this technique, the detection limit of the target was reached to 1 fM and a similar response of current was noted with the target RNA-spiked human serum, indicating the selective identification of target RNA. Further, single mismatched, triple mismatched, and random miRNA sequences (miRNA-195) failed to interact with the immobilized capture DNA, representing the specific identification of target RNA. This nuclease digestion technique with miRNA-21 identification helps in detecting osteosarcoma and related issues.

The effect of miR-539 regulating TRIAP1 on the apoptosis, proliferation, migration and invasion of osteosarcoma cells

Objective

The purpose of this study is to explore the effect of miRNA-539 on osteosarcoma (OS) and the underlying mechanism, so as to find a new method for early diagnosis and treatment of osteosarcoma.

Method

miRNA-539 mimics was transfected into osteosarcoma cells 143b and MG-63 and upregulated the expression of miR-539. QT-PCR was used to detect transfection efficacy. CCK-8 method was used to detect proliferation of 143b and MG-63 osteosarcoma cells and flow cytometry was used to detect the apoptosis of osteosarcoma cells 143b and MG-63. Wound-healing test and Transwell test were used to detect the migration and invasion ability of osteosarcoma cells. TRIAP1 was found to be the potential target gene of miRNA-539 by online bioinformatics software and the expression level of TRIAP1 in osteosarcoma cells overexpressing miRNA-539 was detected by qT-PCR. Western blot was used to detect the level of expression of TRIAP1 and its downstream genes (p53, p21, apaf1 and caspase9) in osteosarcoma cells 143b and MG63 transfected with miR-539 mimics or miR-539 mimics-NC. A model of osteosarcoma subcutaneously transplanted in nude mice was constructed to observe the effect of miRNA-539 on the growth rate of osteosarcoma in vivo.

Results

After transfection of miRNA-539 mimics in osteosarcoma cells 143b and MG63, the proliferation level, migration ability, and invasion ability of the osteosarcoma cells were significantly lower than that in the control group, and the apoptosis level was significantly higher than that in the control group (P < 0.01). The dual luciferase reporter confirmed that TRIAP1 was the target of miR-539, and the expression level of TRIAP1 in 143b and MG63 transfected with miRNA-539 mimics was proved to be significantly lower than that in the control group (P < 0.01).The western blot showed the expression of genes targeted by TRIAP1 was upregulated when the expression of TRIAP1 was downregulated. In vivo, the osteosarcoma growth rate in the miRNA-539 mimics group was significantly slower than that in the control group (P < 0.01).

Conclusions

MiRNA-539 may inhibit the cell proliferation, migration and invasion of osteosarcoma cells and promote the apoptosis of osteosarcoma cells by targeting on TRIAP1.

MicroRNA Expression Changes and Integrated Pathways Associated With Poor Outcome in Canine Osteosarcoma

MicroRNAs (miRNA) are small non-coding RNA molecules involved in post-transcriptional gene regulation. Deregulation of miRNA expression occurs in cancer, and miRNA expression profiles have been associated with diagnosis and prognosis in many cancers. Osteosarcoma (OS), an aggressive primary tumor of bone, affects ~10,000 dogs each year. Though survival has improved with the addition of chemotherapy, up to 80% of canine patients will succumb to metastatic disease. Reliable prognostic markers are lacking for this disease. miRNAs are attractive targets of biomarker discovery efforts due to their increased stability in easily obtained body fluids as well as within fixed tissue. Previous studies in our laboratory demonstrated that dysregulation of genes in aggressive canine OS tumors that participate in miRNA regulatory networks is reportedly disrupted in OS or other cancers. We utilized RT-qPCR in a 384-well-plate system to measure the relative expression of 190 miRNAs in 14 canine tumors from two cohorts of dogs with good or poor outcome (disease-free interval >300 or <100 days, respectively). Differential expression analysis in this subset guided the selection of candidate miRNAs in tumors and serum samples from larger groups of dogs. We ultimately identified a tumor-based three-miR Cox proportional hazards regression model and a serum-based two-miR model, each being able to distinguish patients with good and poor prognosis via Kaplan-Meier analysis with log rank test. Additionally, we integrated miRNA and gene expression data to identify potentially important miRNA-mRNA interactions that are disrupted in canine OS. Integrated analyses of miRNAs in the three-miR predictive model and disrupted genes from previous expression studies suggest the contribution of the primary tumor microenvironment to the metastatic phenotype of aggressive tumors.

Heat treatment dependent cytotoxicity of silicalite-1 films deposited on Ti-6Al-4V alloy evaluated by bone-derived cells

A silicalite-1 film (SF) deposited on Ti-6Al-4V alloy was investigated in this study as a promising coating for metallic implants. Two forms of SFs were prepared: as-synthesized SFs (SF-RT), and SFs heated up to 500 °C (SF-500) to remove the excess of template species from the SF surface. The SFs were characterized in detail by X-ray photoelectron spectroscopy (XPS), by Fourier transform infrared spectroscopy (FTIR), by scanning electron microscopy (SEM) and water contact angle measurements (WCA). Two types of bone-derived cells (hFOB 1.19 non-tumor fetal osteoblast cell line and U-2 OS osteosarcoma cell line) were used for a biocompatibility assessment. The initial adhesion of hFOB 1.19 cells, evaluated by cell numbers and cell spreading area, was better supported by SF-500 than by SF-RT. While no increase in cell membrane damage, in ROS generation and in TNF-alpha secretion of bone-derived cells grown on both SFs was found, gamma H2AX staining revealed an elevated DNA damage response of U-2 OS cells grown on heat-treated samples (SF-500). This study also discusses differences between osteosarcoma cell lines and non-tumor osteoblastic cells, stressing the importance of choosing the right cell type model.

Inhibition of miR-9 decreases osteosarcoma cell proliferation

Osteosarcoma (OS) is the most common primary bone tumor that affects adolescents and young adults. Disruption of microRNA (miRNA) regulation is well established in the pathophysiology of different cancers, including OS. Increased expression of miR-9 in OS positively correlates with the tumor size, clinical stage, and distant metastasis. In the present study, we used two different OS cell lines, MG-63 and Saos-2, as in vitro models. miR-9 inhibitor and miR-9 mimics were used to study the function of miR-9 in these two cell lines. We determined the effect of miR-9 inhibition on cell proliferation, cell cycle, apoptosis, and the protein expression of different genes. Our results demonstrated that miR-9 inhibition in the human OS cell lines suppresses their metastatic potential, as determined by decreased cell proliferation and cell cycle arrest, decreased invasion, and increased apoptosis. The Western blot analysis showed that E-cadherin, matrix metalloproteinase 13, forkhead box O3, Bcl-2-like protein 11, and β-catenin are involved in miR-9 signaling. Moreover, miR-9 mimics rescued the effects caused by the inhibition of miR-9 in the OS cell lines. Our findings suggest that miR-9 is important for mediating OS cell migration, invasion, metastasis, and apoptosis. Inhibition of miR-9 could be further explored as a therapeutic target to treat OS.

The potential of micelleplexes as a therapeutic strategy for osteosarcoma disease

Osteosarcoma (OS) is a rare aggressive bone, presenting low patient survival rate, high metastasis and relapse occurrence, mostly due to multi-drug resistant cells. To surpass that, the use of nanomedicine for the targeted delivery of genetic material, drugs or both have been extensively researched. In this review, we address the current situation of the disorder and some gene therapy options in the nanomedicine field that have been investigated. Among them, polymeric micelles (PM) are an advantageous therapeutic alternative highly explored for OS, as they allow for the targeted transportation of poorly water-soluble drugs to cancer cells. In addition, micelleplexes are PMs with cationic properties with promising features, such as the possibility for a dual therapy, which have made them an attractive research subject. The aim of this review article is to elucidate the application of a micelleplex formulation encapsulating the underexpressed miRNA145 to achieve an active targeting to OS cells and overcome multi-drug resistance, as a new and viable therapeutic strategy.

Identification and validation of microRNAs and their targets expressed in osteosarcoma

Osteosarcoma (OS) is the most common type of bone cancer in children and adolescents, and has a poor prognosis. Previous studies have demonstrated that a number of microRNAs (miRNAs) were deregulated in OS, and that the expression of certain miRNAs was correlated with the stage of OS. Therefore, miRNAs may serve a role as a diagnostic and prognostic biomarker of OS. miRNA and mRNA integrated analysis of public expression profiles in the Gene Expression Omnibus database for OS was performed, and the regulated targets of miRNA in OS were predicted. Next, the regulatory network of miRNAs/genes was constructed and verified by reverse transcription-quantitative polymerase chain reaction in tissues and MG-63 cell lines. Two miRNA expression profiling studies and four eligible mRNA expression profiling studies were selected. Ten upregulated miRNAs, 5 downregulated miRNAs and 5 DGEs were identified in OS compared with normal tissues. hsa-miR-346 was inversely correlated with the target gene c-FLIP, which was consistent with the results of integrated analysis. In vitro, pre-miRNA-346 can downregulate the protein expression of c-FLIP, while not changing the mRNA level of c-FLIP. In the regulatory network, hsa-miR-346 and its target gene, c-FLIP, can be used as biomarkers for an earlier diagnosis of OS.

lncRNA SNHG1 negatively regulates miRNA‑101‑3p to enhance the expression of ROCK1 and promote cell proliferation, migration and invasion in osteosarcoma

Osteosarcoma (OS) is a rare malignant bone tumor that commonly occurs in children and adolescents and causes pain and swelling of the long bones of the legs and arms. Long non-coding RNA (lncRNA) and micro (mi)RNA-101 are important in the initialization and progression of OS. However, the mechanism underlying the role of the lncRNA and miRNA-101 in OS remains to be fully elucidated. In the present study, through reverse transcription-quantitative polymerase chain reaction analysis, it was first found that the lncRNA SNHG1 was upregulated and miRNA-101-3p was downregulated in OS tissues and cell lines. Second, the knockdown of lncRNA SNHG1 induced cell apoptosis and maintained the cell cycle at the G0/G1 phase, which decreased the overall cell viability. Furthermore, according to a dual-luciferase assay and western blot analysis, miRNA-101-3p was found to be a target of the lncRNA SNHG1 in OS, which further regulated the expression of Rho-associated coiled-coil-containing protein kinase 1 (ROCK1). It was found that the phosphoinositide 3-kinase/ATK pathway was inactivated and that epithelial-mesenchymal transition was activated in OS cell lines with overexpression of the lncRNA SNHG1. Taken together, in OS cell lines, the lncRNA SNHG1 acted as an oncogene, and miRNA-101-3p was considered a tumor suppressor. The lncRNA SNHG1 promoted OS cell proliferation, migration and invasion by downregulating the expression of miRNA-101-3p, which enhanced the expression of ROCK1.

LncRNA-PCAT1 targeting miR-145-5p promotes TLR4-associated osteogenic differentiation of adipose-derived stem cells

This study was aimed to explore the differential expression of long noncoding RNAs (lncRNA)‐PCAT1, miR‐145‐5p and TLR4 in osteogenic differentiation via the Toll‐like receptor (TLR) signalling pathway and consequently determine the potential molecular mechanism. The mRNAs and pathways related to the osteogenic differentiation in human adipose‐derived stem cells (hADSCs) were analysed by bioinformatics. The MiRanda and TargetScan database were employed to detect the potential binding sites of miRNAs on lncRNAs and mRNAs. The differential expression of lncRNA‐PCAT1, miR‐145‐5p and TLR4 were detected by qRT‐PCR. Rrelated protein expression was analysed by Western blot. The targeted relationships between lncRNA‐PCAT1, miR‐145‐5p and TLR4 were verified by dual‐luciferase reporter assay. Alkaline phosphatase (ALP) activity and ARS staining assays were used to measure the impacts exerted by lncRNA PCAT1, miR‐145‐5p and TLR4 mRNA on osteogenic differentiation. After the induction of osteoblast differentiation, the expression of lncRNA‐PCAT1 and TLR4 increased, while the expression of miR‐145‐5p decreased. Dual‐luciferase reporter assay confirmed the targeted relationship between lncRNA‐PCAT1, miR‐145‐5p, and TLR4. LncRNA‐PCAT1 negatively regulated miR‐145‐5p and positively regulated TLR4. Knockdown of lncRNA‐PCAT1 or TLR4 decreased the expression of osteogenic differentiation‐related proteins, reduced the ALP and ARS levels and the activity of the TLR signalling pathway. MiR‐145‐5p could reverse the effects of PCAT1 and TLR4 in hADSCs osteogenic differentiation. LncRNA‐PCAT1 negatively regulated miR‐145‐5p, which promoted TLR4 expression to promote osteogenic differentiation by activating the TLR signalling pathway.

MicroRNA-539 inhibits colorectal cancer progression by directly targeting SOX4

Colorectal cancer (CRC) is the third most prevalent cancer and the fourth most common cause of cancer-associated mortality in males and females globally. Aberrant expression of microRNA-539 (miR-539) has been reported in multiple types of cancer. However, miR-539 expression, function and underlying mechanisms have not been clearly elucidated in CRC. In the present study, miR-539 expression was detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) in CRC tissues and cell lines. The effects of miR-539 on CRC cells were further examined in in vitro studies. In addition, the direct targets of miR-539 in CRC were investigated using bioinformatics, luciferase reporter assays, RT-qPCR and western blotting. miR-539 was revealed to be significantly downregulated in CRC cell lines and tissues. Decreased miR-539 expression was associated with lymph node metastasis and tumor-node-metastasis stage in patients with CRC. Functional assays revealed that the rescue of miR-539 expression attenuated CRC cell proliferation and invasion in vitro. Additionally, SRY-box 4 (SOX4) was validated as a direct target gene of miR-539 in CRC. Furthermore, SOX4 was revealed to be upregulated in CRC tissues at the mRNA and protein level. A significant negative correlation between miR-539 and SOX4 mRNA expression levels was observed in CRC tissues. Furthermore, upregulation of SOX4 partially restored the tumor suppressive effects of miR-539 on CRC cell proliferation and invasion. Taken together, this suggests that miR-539 may serve tumor-suppressive functions in CRC during the process of malignant transformation, by directly targeting SOX4. miR-539/SOX4-based targeted therapy may represent a potential novel treatment for patients with CRC.

MicroRNA‑539 inhibits the proliferation and invasion of bladder cancer cells by regulating IGF‑1R

Bladder cancer is the most frequent malignancy of the urinary tract and the seventh most common cancer worldwide. The abnormal expression of microRNAs has been frequently observed in various types of human cancers, including bladder cancer. In addition, an increasing body of evidence has demonstrated that microRNAs are potential targets for cancer diagnosis, treatments and prognosis. The aim of the present study was to investigate the expression patterns and potential roles of microRNA‑539 (miR‑539) in bladder cancer and its underlying mechanism. Reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) was performed to detect miR‑539 expression in the bladder cancer tissues and cell lines. Following transfection, MTT and cell invasion assays were used to investigate the effects of miR‑539 overexpression or IGF1R underexpression on bladder cancer cell proliferation and invasion. Bioinformatics analysis, a luciferase reporter assay, RT‑qPCR and western blot analysis were utilized to determine the potential targets of miR‑539 in bladder cancer. The results revealed that miR‑539 levels were relatively decreased in bladder cancer tissues and cell lines when compared with those observed in the matched adjacent normal bladder tissues and normal bladder epithelial cell line. miR‑539 expression was associated with the tumor stage and lymph node metastasis of patients with bladder cancer. In addition, the expression of miR‑539 suppressed bladder cancer cell proliferation and invasion. Insulin like growth factor 1 receptor (IGF‑1R) was identified as a direct target of miR‑539, and miR‑539 was also observed to regulate the protein kinase B and extracellular signal‑regulated kinases signaling pathways. IGF‑1R was markedly upregulated in bladder cancer tissues and negatively associated with miR‑539 expression levels. Furthermore, IGF‑1R knockdown in bladder cancer cells significantly inhibited cell proliferation and invasion. To the best of our knowledge, these results demonstrated for the first time that miR‑539 may act as a tumor suppressor and serve important roles in tumorigenesis and progression of bladder cancer. Thus, miR‑539/IGF‑1R may be a potential therapeutic target for the treatment of bladder cancer.

MicroRNA-124 acts as a tumor-suppressive miRNA by inhibiting the expression of Snail2 in osteosarcoma

The aim of the present study was to investigate the clinical significance of hsa-microRNA-124-3p (miR-124) in osteosarcoma (OS), and examine its role in cell growth and invasion. Using a microRNA chip array, the expression of miR-124 was detected in samples of surgically resected OS and matched against the levels of expression in tumor-adjacent normal tissues. The levels of miR-124 were upregulated in the OS cells through the transfection of miR-124 mimics. Cell proliferation and Transwell assays were performed to determine cell proliferation and invasion; Reverse transcription-quantitative polymerase chain reaction, western blot and luciferase assays were then used to detect the expression of the target gene snail family zinc finger 2 (Snail2). The expression of miR-124 was significantly lower in the OS tissues, compared with that in the tumor-adjacent normal tissues; and the expression of miR-124 in the tumor tissues was significantly associated with tumor size. miR-124 directly repressed the expression of Snail2, and resulted in a significant inhibition of cell proliferation and invasion. In a mouse model, the overexpression of miR-124 significantly inhibited U2OS cell proliferation and invasion. Taken together, miR-124 was associated with the adverse clinical and pathological features observed in OS. It acted as a tumor suppressor to regulate the proliferation and invasion of OS cells by targeting Snail2, suggesting that miR-124 may be key in the progression of OS.

MicroRNAs for osteosarcoma in the mouse: a meta-analysis

Osteosarcoma (OS) is the most common primary malignant bone carcinoma with high morbidity that happens mainly in children and young adults. As the key components of gene-regulatory networks, microRNAs (miRNAs) control many critical pathophysiological processes, including initiation and progression of cancers. The objective of this study is to summarize and evaluate the potential of miRNAs as targets for prevention and treatment of OS in mouse models, and to explore the methodological quality of current studies. We searched PubMed, Web of Science, Embase, Wan Fang Database, VIP Database, China Knowledge Resource Integrated Database, and Chinese BioMedical since their beginning date to 10 May 2016. Two reviewers separately screened the controlled studies, which estimate the effects of miRNAs on osteosarcoma in mice. A pair-wise analysis was performed. Thirty six studies with enough randomization were selected and included in the meta-analysis. We found that blocking oncogenic or restoring decreased miRNAs in cancer cells could significantly suppress the progression of OS in vivo, as assessed by tumor volume and tumor weight. This meta-analysis suggests that miRNAs are potential therapeutic targets for OS and correction of the altered expression of miRNAs significantly suppresses the progression of OS in mouse models, however, the overall methodological quality of studies included here was low, and more animal studies with the rigourous design must be carried out before a miRNA-based treatment could be translated from animal studies to clinical trials.

miRNA-193a-5p repression of p73 controls Cisplatin chemoresistance in primary bone tumors

Osteosarcoma and Ewing Sarcoma are the two most common types of Bone Sarcomas, principally localized at the long bones of the extremities and mainly affecting adolescents and young adults. Cisplatin is one of the current options in the therapeutic arsenal of drugs available to cure these aggressive cancers. Unfortunately, chemoresistance against this agent is still a major cause of patient relapse. Thus, a better understanding of the molecular pathways by which these drugs induce cancer cell death, together with a better delineation of the origins of chemoresistance are required to improve the success rate of current treatments. Furthermore, as p53 is frequently mutated in Bone Sarcomas, other pathways in these cancers must mediate drug-induced cell death. Here, we demonstrate for the first time that TAp73β, a p53-family protein, is implicated in Cisplatin-induced apoptosis of Bone Sarcomas'. Furthermore, while acquired resistance developed by cancer cells against such drugs can have multiple origins, it is now well accepted that epigenetic mechanisms involving microRNAs (miRNAs) are one of them. We show that miRNA-193a-5p modulates the viability, the clonogenic capacity and the Cisplatin-induced apoptosis of the Bone Sarcoma cells through inhibition of TAp73β. Collectively, these results shed light on the involvement of miR-193a-5p in Cisplatin chemoresistance of Bone Sarcomas', and they open the road to new therapeutic opportunities provided by targeting the miR-193a-5p/TAp73β axis in the context of these malignancies.

MicroRNA-103 Promotes Proliferation and Inhibits Apoptosis in Spinal Osteosarcoma Cells by Targeting p57

Osteosarcoma is one of the most aggressive malignancies with poor prognosis rates. Many studies have demonstrated that miRNAs were involved in osteosarcoma, but the role of miR-103a in osteosarcoma remains elusive. In this study, we detected the expression levels of miR-103 in osteosarcoma and non-osteosarcoma tissues and cell lines. The binding effect of miR-103 on p57 was detected by luciferase reporter assay. After altering expressions of miR-103 or p57, viability, migration, invasion, and apoptosis of MG63 cells and expressions of proteins related with the JNK/STAT and mTOR pathways were all detected. We found the higher expression of miR-103 in osteosarcoma tissues and cell lines compared with non-osteosarcoma tissues and cell lines. miR-103 overexpression promoted survival, migration, and invasion of MG63 cells. Knockdown of miR-103a inhibited cell survival, migration, and invasion by upregulating the expression of p57, which was a target of miR-103. Moreover, miR-103a overexpression activated the JNK/STAT and mTOR pathways probably through inhibiting p57 expression. In conclusion, miR-103a acted as an oncogene in osteosarcoma, probably through activating the JNK/STAT and mTOR pathways by inhibiting p57 expression.

Roles of microRNA-539 and osteopontin in rheumatoid arthritis

The present study aimed to investigate the role and mechanism of microRNA-539 (miR-539) in rheumatoid arthritis (RA). A total of 68 RA patients and 46 osteoarthritis patients were enrolled into the current study. Peripheral blood and joint fluid were collected prior to treatment. Reverse transcription-quantitative polymerase chain reaction was performed to detect osteopontin (OPN) mRNA and miR-539 expression levels, while ELISA and western blot analysis were applied to detect OPN protein expression. In addition, bioinformatics analysis predicted that miR-539 directly targeted OPN, while dual-luciferase assay was used to validate this finding. Furthermore, agomiR-539 transfection and OPN knockdown by siRNA were conducted in MH7A cells, and MTT assay was used to detect MH7A cell proliferation. The results indicated that OPN was significantly increased in the blood and joint fluid of RA patients, while miR-539 expression was significantly decreased in the two types of specimens (P<0.05). Subsequent to silencing OPN by siRNA, the proliferation of MH7A cells was decreased (P<0.05). Following upregulation of miR-539, OPN expression was significantly decreased and cell proliferation was inhibited. Dual-luciferase assay revealed that miR-539 regulated OPN expression through complementary binding to 3'-untranslated region. OPN was also significantly increased in the blood and joint fluid of RA patients, which may be associated with the downregulation of miR-539. Thus, miR-539 may promote the development and progression of RA through regulating OPN.

MicroRNAs as a novel class of diagnostic biomarkers for the detection of osteosarcoma: a meta-analysis

MicroRNAs (miRNAs) have been considered as promising diagnostic biomarkers for many diseases, especially for cancers. Numerous studies have reported the value of miRNAs in the diagnosis of osteosarcoma (OS), but the results vary greatly across different studies. Therefore, we conducted this meta-analysis to assess the prospective diagnostic value of miRNAs in diagnosing OS. All relevant articles from prior to July 28, 2017 were selected from PubMed, EMBASE, Web of Science, Cochrane Library, Chinese National Knowledge Infrastructure, and Wan-fang databases. The Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) was performed to assess the quality of each article. A random-effects model was used to pool the sensitivity and specificity of the positive likelihood ratio (PLR), negative likelihood ratio (NLR) and, diagnostic odds ratio (DOR) together with the area under the curve (AUC) to evaluate diagnostic values. Seventeen studies comprising 2,214 OS patients and 1,534 healthy humans were included in our meta-analysis. The pooled estimations indicated that the miRNAs had a high accuracy for diagnosing OS, with a sensitivity of 0.82, specificity of 0.88, PLR of 10.96, NLR of 0.20, DOR of 54.55, and AUC of 0.93. Twenty-five miRNAs were differentially expressed in OS, including 17 upregulated and 8 downregulated. These miRNAs were correlated with survival time, tumor size, cell differentiation, tumor node metastasis staging, metastasis, tumor/cell invasion, pathological type, and response to radiotherapy and chemotherapy. Several different miRNAs are expressed in OS, and some of them might be potential biomarkers for the early diagnosis of OS.

MiR-302b Suppresses Osteosarcoma Cell Migration and Invasion by Targeting Runx2

Osteosarcoma patients with lung metastasis and local invasion remain challenging to treat despite the significant contribution of the combination of surgery and neo-adjuvant chemotherapy. Our previous microarray study demonstrated that miR-302b had significantly lower expression in osteosarcoma cell lines than in osteoblast cell lines. In the present study, we further elucidated the role of miR-302b in regulating the migration and invasiveness of osteosarcoma. MiR-302b expression was markedly down-regulated in osteosarcoma cell lines and clinical tumour tissues. Lower levels of miR-302b expression were significantly associated with metastasis and high pathological grades. A functional study demonstrated that over-expression of miR-302b suppressed tumour cell proliferation, invasion and migration in vitro and in vivo. Runx2 was identified as a direct target gene for miR-302b by bioinformatics analysis and dual-luciferase reporter gene assay. Moreover, over-expression of miR-302b induced down-regulation of Runx2, OPN, MMP-2, MMP-9, MMP-12, MMP-14, and VEGF in 143B cells. Exogenous expression of Runx2 partially rescued the inhibitory effect of miR-302b on the invasion and migration activity of 143B osteosarcoma cells. Taken together, our results indicate that miR-302b functions as a tumour repressor in the invasion and migration of osteosarcoma by directly downregulating Runx2 expression and may be a potential therapeutic target for osteosarcoma.

miR-200bc/429 Inhibits Osteosarcoma Cell Proliferation and Invasion by Targeting PMP22

Background

MicroRNAs (miRNAs) are small non-coding RNAs which play a crucial role in diverse biological processes and could contribute to cancer development and progression. MiR-200bc/429 have been found to be aberrantly expressed in osteosarcoma (OS). However, the features of miR-200bc/429 in the tumorigenesis and progress of OS remain poorly understood.

Material/Methods

The miR-200bc/429 expression was firstly identified in human OS clinical samples and cell lines by quantitative real-time PCR (qRT-PCR). After transfection with miR-200bc/429 mimics or negative control in U2OS or MG63 cells, cell proliferation was measured by CCK-8 assay. Following that, wound-healing assay and Transwell invasion assay were performed to evaluate cell migration and invasion, respectively. Finally, luciferase reporter assay and Western blot analysis were performed to determine if peripheral myelin protein-22 (PMP22) is a direct target of miR-200bc/429.

Results

Results revealed that miR-200bc/429 were significantly depressed in human OS tissues and cell lines by qRT-PCR. Then, restoration of miR-200bc/429 significantly inhibited cell proliferation (P<0.05) and invasion (P<0.05) in vitro. Luciferase reporter assay and Western blot analysis revealed that miR-200bc/429 could directly target PMP22 3′ untranslated region (UTR) and inhibit its expression in U2OS and MG63 cells.

Conclusions

These findings suggest that miR-200bc/429 inhibit OS cells proliferation and invasion by targeting PMP22, and function as a tumor suppressor and may be a patent molecular marker as well as a potential target for OS therapy.

miR-150 is downregulated in osteosarcoma and suppresses cell proliferation, migration and invasion by targeting ROCK1

Osteosarcoma (OS) is the most common form of bone malignancy in children and adolescents. A class of molecules known as microRNAs (miRNAs) have been routinely associated in the development and progression of OS. The present study was centered on the less well-known miRNA, miRNA (miR)-150, and its role in OS was investigated. The levels of miR-150 were examined in 40 tissue specimens from patients with OS and adjacent normal tissues using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis. In addition the expression levels of miR-150 were examined in three OS cell lines and a normal osteoblast cell line. Cell proliferation, migration and invasion assays were performed to establish the correlation between miR-150 and metastasis. The potential targets of miR-150 were theoretically predicted and one high-scoring target, Rho-associated kinase 1 (ROCK1), was established to be a direct target using RT-qPCR and western blot analyses and Pearson's correlation analysis. The results indicated that miR-150 was downregulated in tissues from patients with OS and cell lines. Secondly, it was shown that the overexpression of miR-150 was inversely correlated with OS cell proliferation, migration and invasion. It was also shown that miR-150 negatively regulated the gene expression of ROCK1 in the OS cell lines. Finally, the interaction between miR-150 and ROCK1 was established and it was shown that miR-150 directly targeted ROCK1. In conclusion, miR-150 was found to be a tumor suppressor, and the suppression of miR-150 resulted in elevation in the levels of ROCK1. This interaction between miR-150 and ROCK1 may be key in the progression of OS. Furthermore, miR-150 or ROCK1 may be potential therapeutic targets for the treatment of OS.

Estrogen stimulates osteoprotegerin expression via the suppression of miR-145 expression in MG-63 cells

Osteoprotegerin (OPG) is implicated in the pathogenesis of postmenopausal osteoporosis, and other metabolic bone diseases caused by estrogen deficiency. Previous studies have demonstrated that estrogen may stimulate OPG expression in osteoblast cells at the transcriptional level; however, whether estrogen can regulate OPG expression at a post-transcriptional level remains elusive. The present study aimed to investigate the role of microRNA (miRNA) in estrogen-mediated OPG production in human osteoblast-like MG-63 cells. The results from ELISA, western blotting and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) confirmed that estrogen may upregulate OPG expression. Mechanistic studies indicated that estrogen increased the activity of a luciferase reporter harboring the OPG 3′-untranslated region (3′-UTR). Bioinformatics analysis demonstrated that there is a potential targeting site in the OPG 3′-UTR for miRNA (miR)-145, which is associated with osteoblast differentiation. The results of an RT-qPCR suggested that estrogen suppressed miR-145 expression. In addition, dual-luciferase assay, RT-qPCR and western blot analysis indicated that miR-145 directly targets and negatively regulates OPG expression. Furthermore, transfection of cells with miR-145 mimics was able to partially inhibit the induction of OPG expression by estrogen, thus confirming the role of miR-145 in estrogen-mediated OPG induction. Taken together, the results of the present study demonstrated that estrogen may post-transcriptionally regulate OPG expression through suppression of miR-145 expression.

MicroRNA-148a Acts as a Tumor Suppressor in Osteosarcoma via Targeting Rho-Associated Coiled-Coil Kinase

MicroRNAs (miRs) have been demonstrated to be involved in the development and progression of osteosarcoma (OS), but the molecular mechanism still remains to be fully investigated. The present study investigated the function of miR-148a in OS, as well as its underlying mechanism. Our data showed that miR-148a was significantly downregulated in OS tissues compared to their matched adjacent normal tissues, and also in OS cell lines compared to normal human osteoblast cells. Low expression of miR-148a was significantly associated with tumor progression and a poor prognosis for OS patients. Rho-associated coiled-coil kinase 1 (ROCK1) was then identified as a target of miR-148a in Saos-2 and U2OS cells, and the expression of ROCK1 was significantly increased in OS tissues and cell lines. Moreover, the protein expression of ROCK1 was markedly reduced in miR-148a-overexpressing Saos-2 and U2OS cells, but significantly increased in miR-148a-downregulated Saos-2 and U2OS cells. Further investigation indicated that miR-148a had a suppressive effect on the proliferative, migratory, and invasive capacities of Saos-2 and U2OS cells. Moreover, overexpression of ROCK1 attenuated the inhibitory effects of miR-148a upregulation on the malignant phenotypes of Saos-2 and U2OS cells. In addition, overexpression of miR-148a significantly inhibited the tumor growth of U2OS cells in nude mice. Taken together, these data demonstrate that miR-148a acts as a tumor suppressor in OS, at least partly, via targeting ROCK1. Therefore, the miR-148a/ROCK1 axis may become a potential therapeutic target for OS.

Diverse roles of miR-335 in development and progression of cancers

MicroRNAs (miRNAs), a series of small noncoding RNAs that regulate gene expression at the post-transcriptional/translational level, are pivotal in cell differentiation, biological development, occurrence, and development of diseases, especially in cancers. Early studies have shown that miRNA-335 (miR-335) is widely dysregulated in human cancers and play critical roles in tumorigenesis and tumor progression. In this review, we aim to summarize the regulation of miR-335 expression mechanisms in cancers. We focus on the target genes regulated by miR-335 and its downstream signaling pathways involved in the biological effects of tumor growth, invasion, and metastasis both in vitro and in vivo, and analyze the relationships between miR-335 expression and the clinical characteristics of tumors as well as its effects on prognosis. The collected evidences support the potential use of miR-335 in prognosis and diagnosis as well as the therapeutic prospects of miR-335 in cancers.

miRNAs Related to Skeletal Diseases

miRNAs as non-coding, short, double-stranded RNA segments are important for cellular biological functions, such as proliferation, differentiation, and apoptosis. miRNAs mainly contribute to the inhibition of important protein translations through their cleavage or direct repression of target messenger RNAs expressions. In the last decade, miRNAs got in the focus of interest with new publications on miRNAs in the context of different diseases. For many types of cancer or myocardial damage, typical signatures of local or systemically circulating miRNAs have already been described. However, little is known about miRNA expressions and their molecular effect in skeletal diseases. An overview of published studies reporting miRNAs detection linked with skeletal diseases was conducted. All regulated miRNAs were summarized and their molecular interactions were illustrated. This review summarizes the involvement and interaction of miRNAs in different skeletal diseases. Thereby, 59 miRNAs were described to be deregulated in tissue, cells, or in the circulation of osteoarthritis (OA), 23 miRNAs deregulated in osteoporosis, and 107 miRNAs deregulated in osteosarcoma (OS). The molecular influences of miRNAs regarding OA, osteoporosis, and OS were illustrated. Specific miRNA signatures for skeletal diseases are described in the literature. Some overlapped, but also unique ones for each disease exist. These miRNAs may present useful targets for the development of new therapeutic approaches and are candidates for diagnostic evaluations.

Integrated bioinformatics analysis of miRNA expression in osteosarcoma

The expression of miRNA influencing the pathogenesis of OS have been reported previously, however, different samples selection and sequencing platforms made obvious differences in miRNA expression analysis. We aim to identify reliable prognostic and treatment biomarkers for OS by systematic analysis of miRNAs expression data sets from biased data set. Seven miRNA data sets were selected from corresponding articles. Collectively, two miRNAs, hsa-miR-19-3p and hsa-miR106b-3p, and transcription factor SIX3 were identified and may be reliable markers for prognostic and treatment of osteosarcoma.

Increased miR-155-5p and reduced miR-148a-3p contribute to the suppression of osteosarcoma cell death

Osteosarcoma (OS) is the most common cancer of bone and the 5th leading cause of cancer-related death in young adults. Currently, 5-year survival rates have plateaued at ~70% for patients with localized disease. Those with disseminated disease have an ~20% 5-year survival. An improved understanding of the molecular genetics of OS may yield new approaches to improve outcomes for OS patients. To this end, we applied murine models that replicate human OS to identify and understand dysregulated microRNAs (miRNAs) in OS. miRNA expression patterns were profiled in murine primary osteoblasts, osteoblast cultures and primary OS cell cultures (from primary and paired metastatic locations) isolated from two genetically engineered murine models of OS. The differentially expressed miRNA were further assessed by a cross-species comparison with human osteoblasts and OS cultures. We identified miR-155-5p and miR-148a-3p as deregulated in OS. miR-155-5p suppression or miR-148a-3p overexpression potently reduced proliferation and induced apoptosis in OS cells, yet strikingly, did not impact normal osteoblasts. To define how these miRNAs regulated OS cell fate, we used an integrated computational approach to identify putative candidate targets and then correlated these with the cell biological impact. Although we could not resolve the mechanism through which miR-148a-3p impacts OS, we identified that miR-155-5p overexpression suppressed its target Ripk1 (receptor (TNFRSF)-interacting serine-threonine kinase 1) expression, and miR-155-5p inhibition elevated Ripk1 levels. Ripk1 is directly involved in apoptosis/necroptosis. In OS cells, small interfering RNA against Ripk1 prevented cell death induced by the sequestration of miR-155-5p. Collectively, we show that miR-148a-3p and miR-155-5p are species-conserved deregulated miRNA in OS. Modulation of these miRNAs was specifically toxic to tumor cells but not normal osteoblasts, raising the possibility that these may be tractable targets for miRNA-based therapies for OS.

Evaluation of gene expression level of CDC5L and MACC1 in poor prognosis and progression of osteosarcoma

Current evidences have indicated that osteosarcoma is strongly associated with abnormal genetic and epigenetic changes that lead to the abnormal expression of oncogenes or methylation of tumor suppressor genes. In the present study, MACC1 and CDC5L mRNA levels in the patients with osteosarcoma were evaluated using quantitative real-time PCR. Our results demonstrated that CDC5L mRNA levels were higher in tumor tissues than in adjacent normal tissues (2.713 ± 0.738 vs. 1.071 ± 0.629; P < 0.05). Moreover, MACC1 was upregulated in tumor bone tissues than in adjacent normal tissues (3.221 ± 0. 624 vs. 1.427 ± 0.456; P < 0.05). Our result demonstrated that high expression of CDC5L was significantly related to advanced TNM stage (P = 0.032). No significant difference was determined between CDC5L mRNA expression and other clinicopathological parameters including age, gender, tumor diameter, location, tumor grade, and histological type. In addition, overexpression of MACC1 was strongly correlated with advanced TNM stage (P = 0.027) and high tumor grade (P = 0.035). Our findings indicated that mRNA level of CDC5L is correlated with advanced TNM stage, and MACC1 may be involved in progression of osteosarcoma.

Up-regulation of miR-130b expression level and down-regulation of miR-218 serve as potential biomarker in the early detection of human osteosarcoma

Background

Osteosarcoma (OS) is a primary malignant bone tumor with high morbidity that principally emerges in children and adolescents. MiRNAs regulate a variety of normal physiologic processes and are involved in tumorigenesis and development of multiple malignancies, including OS. This study was aimed to evaluate the clinical significance of miR-130b and miR-218 in osteosarcoma patient.

Methods

We utilized quantitative real-time PCR to evaluate the level of miR-130b and miR-218 expressions in OS patients and normal tissues and their relationship with clinicopathological features and survival in OS patients.

Results

QRT-PCR indicated that miR-130b expression in tumor tissues was strongly elevated than adjacent non-tumor tissues (P < 0.001), while the level of miR-218 expression in osteosarcoma tissues was down-regulated than adjacent non-tumor tissues (P < 0.001). We evaluated the clinical significance of miR-130b and miR-218 in osteosarcoma. Clinical correlation analysis showed that increased expression of miR-130b and decreased expression of miR-218 were significantly associated with advanced tumor stage (x² = 6.285, P < 0.009; x² = 7.172, P < 0.007), distant metastasis (x²  = 5.528; P < 0.001; x² = 4.617, P < 0.001) and size of tumor (x² = 5.01, P = 0.013; x² = 4.271, P = 0.019).

Conclusions

Taken together, our data indicated that high miR-130b level and low level of miR-218 are associated with poor clinicopathological characteristics. Furthermore, miR-130b may play a key role in the progression of osteosarcoma.

Implications of miR cluster 143/145 as universal anti-oncomiRs and their dysregulation during tumorigenesis

Tumorigenesis is a multistep process, de-regulated due to the imbalance of oncogenes as well as anti-oncogenes, resulting in disruption of tissue homeostasis. In many cases the effect of oncogenes and anti-oncogenes are mediated by various other molecules such as microRNAs. microRNAs are small non-coding RNAs established to post-transcriptionally regulate more than half of the protein coding genes. miR cluster 143/145 is one such cancer-related microRNA cluster which is down-regulated in most of the cancers and is able to hinder tumorigenesis by targeting tumor-associated genes. The fact that they could sensitize drug-resistant cancer cells by targeting multidrug resistant genes makes them potent tools to target cancer cells. Their low levels precede events which lead to cancer progression and therefore could be considered also as biomarkers to stage the disease. Interestingly, evidence suggests the existence of several in vivo mechanisms by which this cluster is differentially regulated at the molecular level to keep their levels low in cancer. In this review, we summarize the roles of miR cluster 143/145 in cancer, their potential prognostic applications and also their regulation during tumorigenesis.

Down-regulation of miR-133a and miR-539 are associated with unfavorable prognosis in patients suffering from osteosarcoma

Background

MicroRNAs (miRNAs) play key roles in cancer development and progression. The purpose of the present study was to determine the expression levels of miR-133a and miR-539 in osteosarcoma patients and to further investigate the clinicopathological, and prognostic value of these miRNAs.

Methods

The expression levels of miR-133a and miR-539 were determined by qRT-PCR. Associations between miRNAs expressions and various clinicopathological characteristics were analyzed. Survival rate was determined with Kaplan–Meier and statistically analyzed with the log-rank method between groups. Survival data were evaluated through multivariate Cox regression analysis

Results

Our findings revealed that the miR-133a expression was significantly decreased in clinical osteosarcoma tissues compared to adjacent normal bone tissues. The expression level of miR-539 was decreased in clinical osteosarcoma tissues as compared to those adjacent normal tissues. Low expressions of miR-133a and miR-539 were significantly association with advanced TNM stage (P = 0.002; P = 0.001), and metastasis or recurrence (P = 0.001; P = 0.01). Furthermore, Kaplan–Meier survival analysis and log-rank test showed that the low expressions of miR-133a and miR-539 were correlated with the reduced overall survival of osteosarcoma patients. Multivariate Cox proportional hazards model showed that decreased expressions of miR-133a and miR-539 (P = 0.007; P = 0.02), TNM stage (P = 0.001; P = 0.002), and metastasis or recurrence (P = 0.005; P = 0.026) were independent prognostic markers of overall survival of patients.

Conclusion

These results suggest that decreased miR-133a and miR-539 expressions may participate in the progression of osteosarcoma. Together, these results showed that miR-133a and miR-539 may have their role in both progression and prognosis of osteosarcoma.

Biological roles of microRNA-140 in tumor growth, migration, and metastasis of osteosarcoma in vivo and in vitro

The objective of this study was to explore the biological roles of microRNA-140 (miR-140) in tumor growth, migration, and metastasis of osteosarcoma (OS) in vivo and in vitro. Between 2007 and 2014, 47 cases of OS samples and normal bone tissue samples adjacent to OS were selected from our hospital. Tissue biopsies from OS patients were used to measure miR-140 levels to obtain a correlation between clinicopathological features and miR-140 expression. In vitro, MG63 human osteosarcoma cells were divided into four groups: blank group, miR-140 mimic group, miR-140 inhibitor group, and negative control (NC; empty plasmid) group. qRT-PCR was used to detect miR-140 expression, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to detect cell proliferation, flow cytometry was used to detect cell cycle distribution, and scratch migration assay was used to detect cell migration. In vivo, the relative expression of miR-140 level in OS tissue was lower than that in the adjacent normal bone tissue. miR-140 expression is inversely correlated with tumor size, Enneking stage, and tumor metastasis. In vitro, compared with blank group and NC group, relative miR-140 expression was increased, cell proliferation was inhibited, cell population in G0/G1 phase was increased, cell population in G2/M phase and S phases and proliferation index (PI), and cell migration distance were decreased in the miR-140 mimic group, but the relative expression and all the cell indexes were found opposite trend in the miR-140 inhibitor group. In conclusion, in vivo and vitro findings provided evidence that miR-140 could inhibit the growth, migration, and metastasis of OS cells.

MicroRNA-539 suppresses osteosarcoma cell invasion and migration in vitro and targeting Matrix metallopeptidase-8

MicroRNAs (miRNA) are a class of small, non-coding RNA that involved in different cancer-related processes. Previous studies have been indicated miR-539 as a tumor suppressor during tumorigenesis. However, the role of miR-539 in osteosarcoma is still unclear. In this study, we demonstrate miR-539 was downregulated in osteosarcoma tissues compared to adjacent normal tissue. Functional study suggests miR-539 inhabits the osteosarcoma cell proliferation, invasion and migration. We also identified that MMP8 was a direct target of miR-539 by the luciferase activity assay. These findings provide evidence that miR-539 plays a key role in inhibiting osteosarcoma cell invasion and migration and can regulating MMP8 expression in osteosarcoma cells. These strongly suggest that exogenous miR-539 may have therapeutic value in treating osteosarcoma.

MicroRNA screening identifies circulating microRNAs as potential biomarkers for osteosarcoma

MicroRNAs (miRNAs) are a family of small non-protein coding RNAs, which regulate the expression of a wide variety of genes at the post-transcriptional level to control numerous biological and pathological processes. Various circulating miRNAs have been identified as potential diagnostic and prognostic biomarkers in multiple types of cancer and disease. The aim of the present study was to identify potential miRNA biomarkers for the early diagnosis and relapse prediction of osteosarcoma (OS). miRNA profiling was performed on serum from patients with osteosarcoma and healthy controls. All putative miRNAs were verified by reverse transcription-quantitative polymerase chain reaction analysis of 20 pre-therapeutic OS patients and 20 healthy individuals. The expression of miR-106a-5p, miR16-5p, miR-20a-5p, miR-425-5p, miR451a, miR-25-3p and miR139-5p was demonstrated to be downregulated in the serum of OS patients when compared with that of the healthy controls. Receiver-operating characteristic curve analyses indicated that these 7 miRNAs may be used as diagnostic biomarkers with the ability to discriminate between the healthy cohort and patients with OS. These results provide novel insights into the use of miRNAs in early blood screening for OS.

Up-Regulation of MiR-300 Promotes Proliferation and Invasion of Osteosarcoma by Targeting BRD7

Increasing reports suggest that deregulated microRNAs (miRNAs) might provide novel therapeutic targets for cancers. However, the expression and function of miR-300 in osteosarcoma is still unknown. In our study, we found that the expression of miR-300 was up-regulated in osteosarcoma tissues and cells compared with paired adjacent non-tumor bone tissues and osteoblastic cells using RT-qPCR. The enforced expression of miR-300 could promote cell proliferation, invasion and epithelial-mesenchymal transition (EMT). Moreover, we identified that bromodomain-containing protein 7 (BRD7), a new tumor suppressor gene, was a direct target of miR-300. Ectopic expression of BRD7 could significantly inhibit miR-300-promoted proliferation, invasion and EMT. Therefore, our results identify an important role for miR-300 in osteosarcoma through regulating BRD7 expression.

Review of microRNA in osteosarcoma and chondrosarcoma

MicroRNAs (miRNAs) are small noncoding RNAs, which play a complex role in posttranscriptional gene expression and can theoretically be used as a diagnostic or prognostic tool, or therapeutic target for neoplasia. Despite advances in the diagnosis and treatment of skeletal sarcomas, including osteosarcoma and chondrosarcoma, much remains unknown regarding their underpinning molecular mechanisms. Given the recent increasing knowledge base of miRNA roles in neoplasia, both as oncogenes and tumor suppressor genes, this review will focus on the available literature regarding the expression profiles and potential roles of miRNA in skeletal sarcomas. Although this is an emerging field, miRNA profiling may be of use in clarifying competing diagnoses of skeletal sarcomas and possibly indicate patient risk of resistance to traditional chemotherapeutic agents. While detecting and targeting miRNAs is currently limited to experimental investigations, miRNA may be utilized for future clinical management of skeletal sarcomas.

Suppression of liver receptor homolog-1 by microRNA-451 represses the proliferation of osteosarcoma cells

Liver receptor homolog-1 (LRH-1) plays an important role in the onset and progression of many cancer types. However, the role of LRH-1 in osteosarcoma has not been well investigated. In this study, the critical role of LRH-1 in osteosarcoma cells was described. Quantitative polymerase chain reaction and Western blot analysis results revealed that LRH-1 was highly overexpressed in osteosarcoma cells. LRH-1 was knocked down by small interfering RNA (siRNA), and this phenomenon significantly inhibited osteosarcoma cell proliferation. Bioinformatics analysis results showed that LRH-1 contained putative binding sites of microRNA-451 (miR-451); this result was further validated through a dual-luciferase activity reporter assay. miR-451 was overexpressed in osteosarcoma cells through transfection of miR-451 mimics; miR-451 overexpression then significantly inhibited LRH-1 expression and cell proliferation. The loss of LRH-1 by siRNA or miR-451 mimics significantly impaired Wnt/β-catenin activity, leading to G0/G1 cell cycle arrest. Results showed that LRH-1 is implicated in osteosarcoma. Therefore, miR-451-induced suppression of LRH-1 can be a novel therapy to treat osteosarcoma.

MicroRNAs in osteosarcoma

Osteosarcoma (OS) is a primary malignant bone tumor with high morbidity that principally emerges in children and adolescents. Presently, the prognosis of OS patients remains poor due to resistance to chemotherapy, highlighting the need for new therapeutic approaches. MicroRNAs (miRNAs), a class of small noncoding RNA molecules, can negatively modulate protein expression at the post-transcriptional level. miRNAs regulate a variety of normal physiologic processes and are involved in tumorigenesis and development of multiple malignancies, including OS. Some miRNAs are differentially expressed in OS tissues, cell lines and serum, and have been shown to correlate with the malignant phenotype and prognosis. These altered miRNAs function as oncogenes or tumor suppressor genes in this process. Moreover, restoration of miRNA expression has shown promise for the treatment of OS. Here, we describe miRNA biochemistry with a focus on expression profile, role and therapeutic potential in OS. A better understanding will facilitate the identification and characterization of novel biomarkers and development of miRNA-targeted therapies.

A polymorphism site in the pre‑miR‑34a coding region reduces miR‑34a expression and promotes osteosarcoma cell proliferation and migration

Osteosarcoma (OS) is the most prevalent primary malignant bone tumor in children and young adults, its complex etiology involving a combination of environmental and genetic factors. MicroRNA (miRNA) is a short, non-coding regulatory RNA molecule that represses gene expression by imperfectly base-pairing to the 3′ untranslated region of target mRNAs. Evidence has shown that alterations in the expression of miRNA are involved in the initiation, progression, and metastasis of human cancers. It is believed that miRNAs function both as tumor suppressors and oncogenes during cancer development. In the present study, three tumor-associated miRNAs (miR-21, miR-34a and miR-146a) coding regions were screened in Chinese-Han OS patients. A G>A variation in the pre-miR-34a coding region was found to be associated with higher OS morbidity. By detecting the mature miR-34a expression in cells transfected with pre-miR-34a expression vectors of different genotypes using quantitative polymerase chain reaction, it was demonstrated that the G>A variation reduced miR-34a expression in vitro. This was in accordance with the data collected from tumor tissue and patient serum samples. Subsequently, a dual-luciferase reporter assay and western blot analysis were used to detect the site variation effect on the expression of c-Met, a target gene of miR-34a. The G>A variation downregulated the suppression of c-Met in two OS cell lines. Furthermore, it was found that reduced miR-34a expression decreased the suppression of OS cell proliferation in vitro. In conclusion, the present study established the association between miR-34a and the risk of suffering OS in a Chinese Han population by identifying one functional single nucleotide polymorphism site in pre-miR-34a. These findings may give insight into the mechanism of OS development and create an opportunity to approach the diagnosis and treatment of OS.

MicroRNA-9 expression is a prognostic biomarker in patients with osteosarcoma

BACKGROUND

The purpose of the present study was to examine the expression levels of microRNA-9 (miR-9) in osteosarcoma tissues and normal bone tissues, and investigate the relationships between miR-9 expression, clinicopathological features and the prognosis of patients with osteosarcoma.

METHODS

The expression levels of miR-9 in osteosarcoma tissues and corresponding non-cancerous tissues were detected using a real-time quantitative assay. Differences in patient survival were determined using the Kaplan-Meier method and a log-rank test. A Cox proportional hazards regression analysis was used for univariate and multivariate analyses of prognostic values.

RESULTS

Compared to non-cancerous bone tissues, the expression levels of miR-9 in osteosarcoma tissues were significantly elevated (P < 0.001). We found that the expression level of miR-9 was significantly associated with tumor size (P = 0.011), clinical stage (P = 0.009) and distant metastasis (P < 0.001). The Kaplan-Meier curve showed that patients with low miR-9 expression survived significantly longer than patients with high miR-9 expression (P = 0.0017). Multivariate analysis suggested that miR-9 expression level (P = 0.002) is an independent prognostic factors for overall survival.

CONCLUSIONS

The findings of our study suggest that increased miR-9 expression has a strong correlation with the aggressive progression of osteosarcoma and its overexpression is a statistically significant risk factor affecting overall survival, suggesting that increased miR-9 expression could be a valuable marker of tumor progression and for prognosis of osteosarcoma.

Establishment and analysis of osteosarcoma cell sublines with different metastatic characteristics

The aim of this study is to establish human osteosarcoma MG-63 cell sublines with different metastatic characteristics and provide good experimental models for mechanism study of osteosarcoma metastasis. Six cell sublines were screened and established by using the in vitro cloning technology. In vitro invasion experiments, cellular electrophoretic mobility determinations, cellular proliferation rate determinations, and soft agar clone formation assays were used to compare, analyze, and identify the metastatic characteristics of various cell sublines. The results indicated that the invasion capacity, cellular electrophoretic mobility, cell proliferation, and soft agar clone formation capacity of A2, A3, and A16 sublines were higher than those of A1, A6, and A20 sublines. There was no significant difference in various values determined among A2, A3, and A16, and among A1, A6, and A20 (P > 0.05), but there were significant differences in various values determined between the former three and the latter three (P < 0.05). In conclusion, MG-63 cell sublines with different metastatic characteristics can be established by combining several technologies and can contribute to further research on the mechanism of osteosarcoma metastasis.

MiR-143 suppresses osteogenic differentiation by targeting Osterix

Osterix (Osx) is an essential transcription factor for osteoblast differentiation and bone formation. However, the knowledge of the regulation of Osx expression is poor. MicroRNAs (miRNAs), a class of small non-coding RNAs, play critical roles in numerous biological processes, including the proliferation, differentiation, and survival of cells and organisms. Herein, we aimed to explore the effect of miR-143 on Osx expression and osteogenic differentiation. miR-143, which was suppressor of the osteogenic differentiation of MC3T3-E1 cells, had decreased levels of expression during osteogenic differentiation. Moreover, Osx was identified to be a direct target of miR-143. Inhibition of Osx performed similar effect with miR-143 on osteogenic differentiation, while overexpression of Osx could partially reverse the suppressive effect of miR-143. Collectively, these data indicate that miR-143 is a novel regulator of Osx, and it might play an essential role in the regulation of osteogenic differentiation.