MicroRNA function and dysregulation in bone tumors: the evidence to date

Pharmacokinetics and drug-likeness of anti-cancer traditional Chinese medicine: molecular docking and molecular dynamics simulation study

MCM7 (Minichromosome Maintenance Complex Component 7) is a component of the DNA replication licensing factor, which controls DNA replication. The MCM7 protein is linked to tumor cell proliferation and has a function in the development of several human cancers. Several types of cancer may be treated by inhibiting the protein, as it is strongly produced throughout this process. Significantly, Traditional Chinese Medicine (TCM), which has a long history of clinical adjuvant use against cancer, is rapidly gaining traction as a valuable medical resource for the development of novel cancer therapies, including immunotherapy. Therefore, the goal of the research was to find small molecular therapeutic candidates against the MCM7 protein that may be used to treat human cancers. A computational-based virtual screening of 36,000 natural TCM libraries is carried out for this goal using a molecular docking and dynamic simulation technique. Thereby, ∼8 novel potent compounds i.e., ZINC85542762, ZINC95911541, ZINC85542617, ZINC85542646, ZINC85592446, ZINC85568676, ZINC85531303, and ZINC95914464 were successfully shortlisted, each having the capacity to penetrate the cell as potent inhibitors for MCM7 to curb this disorder. These selected compounds were found to have high binding affinities compared to the reference (AGS compound) i.e. < -11.0 kcal/mol. ADMET and pharmacological properties showed that none of these 8 compounds poses any toxic property (carcinogenicity) and have anti-metastatic, and anticancer activity. Additionally, MD simulations were run to assess the compounds' stability and dynamic behavior with the MCM7 complex for about 100 ns. Finally, ZINC95914464, ZINC95911541, ZINC85568676, ZINC85592446, ZINC85531303, and ZINC85542646 are identified as highly stable within the complex throughout the 100 ns simulations. Moreover, the results of binding free energy suggested that the selected virtual hits significantly bind to the MCM7 which implied these compounds may act as a potential MCM7 inhibitor. However, in vitro testing protocols are required to further support these results. Further, assessment through various lab-based trial methods can assist with deciding the action of the compound that will give options in contrast to human cancer immunotherapy.Communicated by Ramaswamy H. Sarma.

Oncomeric Profiles of microRNAs as New Therapeutic Targets for Treatment of Ewing's Sarcoma: A Composite Review

Ewing's sarcoma is a rare type of cancer that forms in bones and soft tissues in the body, affecting mostly children and young adults. Current treatments for ES are limited to chemotherapy and/or radiation, followed by surgery. Recently, microRNAs have shown favourable results as latent diagnostic and prognostic biomarkers in various cancers. Furthermore, microRNAs have shown to be a good therapeutic agent due to their involvement in the dysregulation of various molecular pathways linked to tumour progression, invasion, angiogenesis, and metastasis. In this review, comprehensive data mining was employed to explore various microRNAs that might have therapeutic potential as target molecules in the treatment of ES.

Potential biomarkers for the early detection of bone metastases

The clinical manifestations of bone metastases are diversified while many sites remain asymptomatic at early stage. As the early diagnosis method is not perfect and the early symptoms of tumor bone metastasis are not typical, bone metastasis is not easy to be detected. Therefore, the search for bone metastasis-related markers is effective for timely detection of tumor bone metastases and the development of drugs to inhibit bone metastases. As a result, bone metastases can only be diagnosed when symptoms are found, increasing the risk of developing skeletal-related event (SREs), which significantly impairs the patient's quality of life. Therefore, the early diagnosis of bone metastases is of great importance for the treatment and prognosis of cancer patients. Changes of bone metabolism indexes appear earlier in bone metastases, but the traditional biochemical indexes of bone metabolism lack of specificity and could be interfered by many factors, which limits their application in the study of bone metastases. Some new biomarkers of bone metastases have good diagnostic value, such as proteins, ncRNAs, circulating tumor cells (CTCs). Therefore, this study mainly reviewed the initial diagnostic biomarkers of bone metastases which were expected to provide references for the early detection of bone metastases.

Indoleamine 2,3-dioxygenase 1 promotes osteosarcoma progression by regulating tumor-derived exosomal miRNA hsa-miR-23a-3p

Background: Osteosarcoma (OS) is the most common primary malignant tumor originating in bone. Immunosuppressive enzyme indoleamine 2,3-dioxygenase 1 (IDO1) participates in tumor immune tolerance and promotes tumor progression, while the study of IDO1 in OS is limited. Methods: Immunohistochemistry analysis was performed to test the expression of IDO1 and Ki67. The relationship between IDO1 or Ki67 positive count and clinical stage of the patient was analyzed. Laboratory test indexes including serum alkaline phosphatase (ALP), lactate dehydrogenase (LDH), white blood cell (WBC) count and C-reactive protein (CRP) at diagnosis of OS patients were collected. The relationship between positive count of IDO1 and Ki67 or laboratory test indexes was analyzed by Pearson's correlation analysis. IDO1 stably overexpressed cell lines of these cells (MG63 OE, 143B OE and hFOB1.19 OE) were constructed and validated by Western blot and Elisa. Exosomes were isolated from conditioned culture media of these cells and were identified by Zetaview nanoparticle tracking analyzer. Next-generation sequencing was conducted to identify miRNAs enriched in exosomes. Differentially expressed miRNAs (DE miRNAs) were verified in clinical samples and cell lines by qPCR. Biological processes and cell components analysis of DE miRNAs was conducted by GO enrichment analysis using the protein interaction network database. Results: Immunosuppressive enzyme IDO1 was highly expressed in tumor tissues. 66.7% (6/9) of the tissues showed moderately or strongly positive immunostaining signal of IDO1, and 33.3% (3/9) were weakly positive. The expression of IDO1 was positively related to Ki67 and associated with prognostic-related clinical features of OS patients. Overexpression of IDO1 significantly affected the exosome-derived miRNA subsets from MG63, 143B and hFOB1.19 cells. A total of 1244 DE miRNAs were identified, and hsa-miR-23a-3p was further screened as key DE miRNA involved in the progression of OS. GO analysis of target genes of the DE miRNA results showed that target enrichment in the functions of immune regulation and tumor progression. Discussion: Our results indicate that IDO1 has the potential to promote the progression of OS that is related to miRNAs mediated tumor immunity. Targeting IDO1-mediated hsa-miR-23a-3p may be a potential therapeutic strategy for OS treatment.

Palmitic acid-induced microRNA-143-5p expression promotes the epithelial-mesenchymal transition of retinal pigment epithelium via negatively regulating JDP2

BACKGROUND

The epithelial-mesenchymal transition (EMT) of retinal pigment epithelial (RPE) cells is the most crucial step in the etiopathogenesis of proliferative vitreoretinopathy. This study aimed to investigate the role of miR-143-5p in the EMT of RPE cells induced by palmitic acid (PA).

METHODS

ARPE-19 cells were treated with PA to induce EMT, followed by E-cadherin and α-smooth muscle actin (α-SMA) expression and the microRNA expression profile analyses. Subsequently, miR-143-5p mimics/inhibitors, and plasmids expressing its predicted target gene c-JUN-dimerization protein 2 (JDP2), were transfected in ARPE-19 cells using lipofectamine 3000, and followed by PA treatment. Their impacts on EMT were explored using wound healing and Western blot assays. Additionally, miR-143-5p mimics and JDP2-expressing plasmid were co-transfected into ARPE-19 cells and treated with PA to explore whether PA induced EMT of ARPE-19 cells via the miR-143-5p/JDP2 axis.

RESULTS

PA decreased E-cadherin expression and increased those of α-SMA and miR-143-5p. Inhibiting miR-143-5p suppressed the migration of ARPE-19 cells and altered the expressions of E-cadherin and α-SMA. However, additional PA treatment attenuated these alterations. JDP2 was a target of miR-143-5p. Overexpression of JDP2 inhibited the EMT of ARPE-19 cells, resulting in α-SMA downregulation and E-cadherin upregulation, which were reversed by additional PA treatment via inhibiting JDP2 expression. Overexpression of miR-143-5p reversed the effect of JDP2 on the EMT of ARPE-19 cells and additional PA treatment markedly enhanced the effect of miR-143-5p mimics.

CONCLUSION

PA promotes EMT of ARPE-19 cells via regulating the miR-143-5p/JDP2 axis, and these findings provide significant insights into the potential targeting of this axis to treat proliferative vitreoretinopathy.

Epigenetic Abnormalities in Chondrosarcoma

In recent years, our understanding of the epigenetic mechanisms involved in tumor pathology has improved greatly. DNA and histone modifications, such as methylation, demethylation, acetylation, and deacetylation, can lead to the up-regulation of oncogenic genes, as well as the suppression of tumor suppressor genes. Gene expression can also be modified on a post-transcriptional level by microRNAs that contribute to carcinogenesis. The role of these modifications has been already described in many tumors, e.g., colorectal, breast, and prostate cancers. These mechanisms have also begun to be investigated in less common tumors, such as sarcomas. Chondrosarcoma (CS) is a rare type of tumor that belongs to sarcomas and is the second most common malignant bone tumor after osteosarcoma. Due to unknown pathogenesis and resistance to chemo- and radiotherapies of these tumors, there is a need to develop new potential therapies against CS. In this review, we summarize current knowledge on the influence of epigenetic alterations in the pathogenesis of CS by discussing potential candidates for future therapies. We also emphasize ongoing clinical trials that use drugs targeting epigenetic modifications in CS treatment.

An improved method for isolation of RNA from rat femur

BACKGROUND

RNA isolation from ossified bone is a difficult and time-consuming process which often results in poor recovery of RNA. The yield is limited and might not be suitable for gene quantification studies by real time PCR.

METHODOLOGY

The present study demonstrates RNA extraction from rat femur utilizing the silica column along with the trizol reagent. Quality of RNA was assessed by agarose gel analysis and its suitability for real-time PCR analysis was determined by β-actin Ct values.

RESULTS

The RNA isolated using silica columns in conjugation with trizol reagent resulted in higher yield of RNA and purity (A260/280=2.04; yield =1545.73 µg/ml) compared to the trizol method alone (A260/280=1.85; yield =571.2 µg/ml). Ct value of β actin obtained from RNA isolated by trizol method was higher than the Ct value obtained by trizol in conjugation with the column method (31.41 and 15.41 respectively).

CONCLUSION

Combination of trizol along with silica column resulted in better quality and improved yield of RNA suitable for gene quantification by Real time PCR.

miR-30 inhibits the progression of osteosarcoma by targeting MTA1

OBJECTIVES

MicroRNAs (miRNAs) have been considered as a new class of novel diagnostic and predictive biomarker in many diseases. However, there are few studies on miRNA in osteosarcoma (OS). This study aimed to investigate the roles of miR-30 on OS occurrence and development.

METHODS

PCR was used to detect mRNA levels of miR-30 and MTA1 in cancer tissues, adjacent non-cancerous tissues from OS patients. Western blot was used to detect MTA1 protein expression in all tissues and cell lines (hFOb1.19,Saos-2, MG63, and U2OS). The correlation between miR-30 and MTA1 was predicted through bioinformatics software, and identified by a luciferase reporting experiment. In vitro, functional test detected the specific effects of miR-30 and MTA1 on the development of OS.

RESULTS

miR-30 expression was significantly reduced, while the expression of MTA1 was increased in OS tissues and cells. Luciferase reporting experiment showed that miR-30 sponged MTA1 which was negatively correlated with miR-30 expression. Furthermore, rescue tests revealed that MTA1 restrained the functions of miR-30 on cell proliferation and migration of OS.

CONCLUSION

Our finding showed that miR-30 modulated the proliferation and migration by targeting MTA1 in OS.

A comprehensive exploration of pharmacological properties, bioactivities and inhibitory potentiality of luteolin from Tridax procumbens as anticancer drug by in-silico approach

Tridax procumbens is a flowering plant of the Asteraceae family with a wide range of medicinal uses like anti-inflammatory, anti-diabetic, anti-microbial, immunomodulatory, etc. This study aimed to investigate the anti-cancerous activity of human lung cancer for targeting luteolin, a phytochemical of Tridax procumbens. The computational study has been done for studying the structural properties of luteolin. The drug-likeness of the molecule has been predicted by virtual screening of ADMET properties. The molecular docking technique of the in-silico method is performed to check the complex formation between protein and ligand. The reactivity and stability of the molecule are investigated with the help of molecular dynamics (MD) simulations. In the present work, we have tried to establish a strong candidature of any of the phytochemical of Tridax Procumbens as an inhibitor against human lung cancer.

GATA4 regulates osteogenic differentiation by targeting miR-144-3p

Numerous studies have demonstrated that microRNAs (miRNAs or miRs) play an important role in regulating osteogenic differentiation, but their specific regulatory mechanism requires further investigation. In the present study, it was revealed that during osteogenic differentiation of rat bone marrow mesenchymal stem cells (BMSCs), the expression level of miR-144-3p was decreased with increased osteogenic induction duration and was negatively associated with osteogenic marker gene expression. Overexpression of miR-144-3p inhibited osteogenic differentiation, while inhibition of miR-144-3p expression promoted osteogenic differentiation. In addition, dual-luciferase activity analysis and adenovirus infection experiments revealed that GATA binding protein 4 targeted miR-144-3p for regulation and that overexpression of GATA4 promoted the expression of miR-144-3p. These data indicated that miR-144-3p plays a role in inhibiting BMSC osteogenic differentiation and that GATA4 inhibits osteogenic differentiation by targeting miR-144-3p expression.

MicroRNA-382-5p inhibits osteosarcoma development and progression by negatively regulating VEZF1 expression

Human osteosarcoma is the most frequent malignant primary bone tumor that mainly occurs in young adults and children. MicroRNAs (miRNAs/miRs) are abnormally expressed in human osteosarcoma and contribute to osteosarcoma initiation and development. The present study aimed to investigate the role of miR-382-5p in the nosogenesis of osteosarcoma and to identify a novel target for osteosarcoma treatment. miR-382-5p expression was detected in human osteosarcoma clinical tissues and cell lines, including 143B, U2OS and MG63, via reverse transcription-quantitative PCR analysis. Multiple bioinformatic prediction toowe used to identify the potential target genes of miR-382-5p and vascular endothelial zinc finger 1 (VEZF1), which were validated via the dual-luciferase reporter assay. MG63 and U2OS cells were transfected with miR-382-5p mimics. The Cell Counting Kit-8 assay was performed to assess cell proliferation, while the Transwell assay was performed to assess migration and invasion. Cell colony formation was measured via crystal violet staining, and apoptosis was assessed via Annexin V/propidium iodide staining. The wound healing assay was performed to assess the migratory ability of U2OS and MG63 cells. Antitumor effects of miR-382-5p were evaluated in nude mice xenografts using U2OS cells. The results demonstrated that miR-382-5p expression was markedly downregulated in human osteosarcoma tissues and cell lines compared with adjacent normal tissues. Transfection of miR-382-5p mimics into MG63 and U2OS cells significantly inhibited the malignant behaviors of cells, including decreased proliferation, migration, diminished colony formation and invasion, and promoted osteosarcoma cell apoptosis. Bioinformatics prediction indicated that VEZF1 is a direct target gene of miR-382-5p. Overexpression of VEZF1 restored osteosarcoma tumor development inhibited by miR-382-5p in vivo. In addition, overexpression of miR-382-5p restrained the growth of xenograft osteosarcoma in nude mice following co-transfection, and overexpression of VEZF1 attenuated the inhibitory effect of miR-382-5p in nude mice. miR-382-5p acted as a tumor suppressor gene and inhibited the malignant biological behaviors of human osteosarcoma cells and functions associated with directly targeting VEZF1. Taken together, these results suggest that the miR-382-5p/VEZF1 interaction has an important role in osteosarcoma development and progression, and thus may be used as a diagnostic and therapeutic target for osteosarcoma.

Multiple targets identified with genome wide profiling of small RNA and mRNA expression are linked to fracture healing in mice

Long-bone fracture is a common injury and its healing process at the fracture site involves several overlapping phases, including inflammation, migration of mesenchymal progenitors into the fracture site, endochondral ossification, angiogenesis and finally bone remodelling. Increasing evidence shows that small noncoding RNAs are important regulators of chondrogenesis, osteogenesis and fracture healing. MicroRNAs are small single-stranded, non-coding RNA-molecules intervening in most physiological and biological processes, including fracture healing. Angiogenin-cleaved 5' tRNA halves, also called as tiRNAs (stress-induced RNAs) have been shown to repress protein translation. In order to gain further understanding on the role of small noncoding RNAs in fracture healing, genome wide expression profiles of tiRNAs, miRNAs and mRNAs were followed up to 14 days after fracture in callus tissue of an in vivo mouse model with closed tibial fracture and, compared to intact bone and articular cartilage at 2 months of age. Total tiRNA expression level in cartilage was only approximately one third of that observed in control D0 bone. In callus tissue, 11 mature 5'end tiRNAs out of 191 tiRNAs were highly expressed, and seven of them were differentially expressed during fracture healing. When comparing the control tissues, 25 miRNAs characteristic to bone and 29 miRNAs characteristic to cartilage tissue homeostasis were identified. Further, a total of 54 out of 806 miRNAs and 5420 out of 18,700 mRNAs were differentially expressed (DE) in callus tissue during fracture healing and, in comparison to control bone. They were associated to gene ontology processes related to mesenchymal tissue development and differentiation. A total of 581 miRNA-mRNA interactions were identified for these 54 DE miRNAs by literature searches in PubMed, thereby linking by Spearman correlation analysis 14 downregulated and 28 upregulated miRNAs to 164 negatively correlating and 168 positively correlating miRNA-mRNA pairs with chondrogenic and osteogenic phases of fracture healing. These data indicated that tiRNAs and miRNAs were differentially expressed in fracture callus tissue, suggesting them important physiological functions during fracture healing. Hence, the data provided by this study may contribute to future clinical applications, such as potential use as biomarkers or as tools in the development of novel therapeutic approaches for fracture healing.

Adhesion of monocytes and endothelial cells isolated from the human aorta suppresses by miRNA-PEI particles

Background

Knowledge of stenosis in coronary arteries requires an understanding of the cellular and molecular processes that occur throughout the leukocyte rolling process. In this study, the roles of miR-125a-5p and miR-495-3p were investigated on the adhesion of endothelial cells (ECs) isolated from the human aorta.

Methods

Human primary endothelial cells were obtained from the aorta of people who had died of brain death. Whole blood was used to isolate the monocytes. The miR-125 and miR-495 were predicted and transfected into ECs using Poly Ethylene Imine (PEI). The expression levels of adhesion molecules and monocyte recruitment were identified by the RT-qPCR technique and Leukocyte-Endothelial Adhesion Assay kit, respectively.

Results

The ICAM-1, ICAM-2 and VCAM-1 expression levels decreased significantly in the miR-495/PEI-transfected ECs (P < 0.05) while in the miR-125/PEI-transfected ECs only the ICAM-2 and ITGB-2 expression levels decreased significantly (P < 0.05) as compared to the miR-synthetic/PEI-transfected ECs. Furthermore, the monocyte adhesion was decreased in the miR-125 and miR-mix/PEI-transfected ECs as compared to the miR-synthetic/PEI-transfected ECs (P = 0.01 and P = 0.04, respectively).

Conclusion

According to the findings, the efficient relations between miR-125 and adhesion molecules may be responsible for the inhibition of monocyte rolling.

Osteosarcoma, chondrosarcoma and Ewing sarcoma: Clinical aspects, biomarker discovery and liquid biopsy

Bone sarcomas, although rare, are associated with significant morbidity and mortality. The most frequent primary bone cancers include osteosarcoma, chondrosarcoma and Ewing sarcoma. The treatment approaches are heterogeneous and mainly chosen based on precise tumour staging. Unfortunately, clinical outcome has not changed significantly in over 30 years and tumour grade is still the best prognosticator of metastatic disease and survival. An option to improve this scenario is to identify molecular biomarkers in the early stage of the disease, or even before the disease onset. Blood-based liquid biopsies are a promising, non-invasive way to achieve this goal and there are an increasing number of studies which investigate their potential application in bone cancer diagnosis, prognosis and personalised therapy. This review summarises the interplay between clinical and molecular aspects of the three main bone sarcomas, alongside biomarker discovery and promising applications of liquid biopsy in each tumour context.

Urchin-like Hydroxyapatite/Graphene Hollow Microspheres as pH-Responsive Bone Drug Carriers

Hydroxyapatite (HA) is the main inorganic component of human bones and teeth. It has good biocompatibility and bioactivity, which promotes its good application prospects in the field of bone drug carriers. In this study, tetraethylenepentamine-graphene (rGO-TEPA)/CaCO₃:HA composite microspheres were prepared via microwave hydrothermal synthesis using rGO-TEPA/CaCO₃ solid microspheres as intermediates. Furthermore, the incompletely transformed CaCO₃ was removed by soaking in a citric acid buffer to obtain rGO-TEPA/HA hollow composite microspheres. The two types of as-prepared composite microspheres exhibited sea urchin-like structures, large BET surface areas, and good dispersibility. Mouse preosteoblast cells (MC3T3-E1) were used for in vitro cytotoxicity experiments. The in vitro cell viability test showed that the two composite drug carriers exhibited noncytotoxicity. Moreover, the doxorubicin (DOX) loading and releasing investigations revealed that the two types of prepared carriers had mild storage-release behaviors and good pH responsiveness. Hence, these rGO-TEPA/HA hollow microspheres have promising applications as bone drug carriers.

A 10-year bibliometric analysis of osteosarcoma and cure from 2010 to 2019

BACKGROUND

In recent decades, the 5-year survival rate of osteosarcoma remains poor, despite the variety of operations, and exploration of drug therapy has become the key to improvement. This study investigates the contribution of different aspects in osteosarcoma and cure, and predicts research hotspots to benefit future clinical outcomes.

METHODS

The Web of Science and PubMed databases were queried to collect all relevant publications related to osteosarcoma and cure from 2009 to 2019. These data were imported into CiteSpace and the Online Analysis Platform of Literature Metrology for bibliometric analysis. Bi-clustering was performed on Bibliographic Item co-occurrence Matrix Builder (BICOMB) and gCLUTO to identify hotspots. Additionally, completed clinical trials on osteosarcoma with results past phase II were collated.

RESULTS

A total of 2258 publications were identified in osteosarcoma and cure from 2009 to 2019. China has the largest number of publications (38.49%), followed by the United States (23.03%) with the greatest impact (centrality = 0.44). The centrality of most institutions is < 0.1, and Central South University and Texas MD Anderson Cancer Center possess the highest average citation rates of 3.25 and 2.87. BMC cancer has the highest average citation rate of 3.26 in 772 journals. Four authors (Picci P, Gorlick R, Bielack SS and Bacci G) made the best contributions. We also identified eight hotspots and collected 41 clinical trials related to drug research on osteosarcoma.

CONCLUSIONS

The urgent need exists to strengthen global academic exchanges. Overcoming multidrug resistance in osteosarcoma is the focus of past, present and future investigations. Transformation of the metastasis pattern, microenvironment genetics mechanism, alternative methods of systemic chemotherapy and exploration of traditional Chinese medicine is expected to contribute to a new upsurge of research.

[The regulatory role of microRNA in osteogenic differentiation of mesenchymal stem cells and its application as a therapeutic target and diagnostic tool in orthopedic diseases]

Objective

To summarize the research progress of the regulatory role of microRNA (miRNA) in osteogenic differentiation of mesenchymal stem cells (MSCs) and its application as a therapeutic target and diagnostic tool in orthopedic diseases.

Methods

The recent literature on the regulation of MSCs osteogenic differentiation by miRNAs was extensively reviewed, and its regulatory mechanism and its application as a therapeutic target and diagnostic tool in orthopedic diseases were reviewed.

Results

miRNAs are small endogenous non-coding RNAs with a length of 20-22 nucleotides, which play an important role in the osteogenic differentiation of MSCs. Osteogenesis begins with the differentiation of MSCs into mature osteoblasts, and each stage of dynamic homeostasis of bone metabolism is associated with the regulation of different miRNAs. miRNAs are regulated from the post-transcriptional level by mRNAs cleavage, degradation, translational repression, or methylation. In addition, current studies suggest that miRNAs can be used as a new diagnostic tool and therapeutic target for orthopedic diseases.

Conclusion

Further study on the regulation mechanism of miRNAs will provide more ideas for finding new therapeutic targets and diagnostic tools for orthopedic disease.

The new horizon of liquid biopsy in sarcoma: the potential utility of circulating tumor nucleic acids

The diagnosis, treatment and prognosis of sarcoma are mainly dependent on tissue biopsy, which is limited in its ability to provide a panoramic view into the dynamics of tumor progression. In addition, effective biomarkers to monitor the progression and therapeutic response of sarcoma are lacking. Liquid biopsy, a recent technological breakthrough, has gained great attention in the last few decades. Nucleic acids (such as DNA, mRNAs, microRNAs, and long non-coding RNAs) that are released from tumors circulate in the blood of cancer patients and can be evaluated through liquid biopsy. Circulating tumor nucleic acids reflect the intertumoral and intratumoral heterogeneity, and thus liquid biopsy provides a noninvasive strategy to examine these molecules compared with traditional tissue biopsy. Over the past decade, a great deal of information on the potential utilization of circulating tumor nucleic acids in sarcoma screening, prognosis and therapy efficacy monitoring has emerged. Several specific gene mutations in sarcoma can be detected in peripheral blood samples from patients and can be found in circulating tumor DNA to monitor sarcoma. In addition, circulating tumor non-coding RNA may also be a promising biomarker in sarcoma. In this review, we discuss the clinical application of circulating tumor nucleic acids as blood-borne biomarkers in sarcoma.

LncRNA OR3A4 Regulated the Growth of Osteosarcoma Cells by Modulating the miR-1207-5p/G6PD Signaling

Background

Increasing evidence has demonstrated the importance of non-coding RNAs including long non-coding RNA (lncRNA) and microRNAs (miRNAs) in the tumorigenesis of osteosarcoma (OS). Abnormal expression of lncRNA olfactory receptor family 3 subfamily A member 4 (OR3A4) was found in multiple human cancers; however, the function of OR3A4 in OS remains largely unknown.

Materials and Methods

The expression level of OR3A4 in OS tissues and cell lines was detected by RT-qPCR. Cell counting kit-8 assay, colony formation and flow cytometry analysis were performed to determine the growth of OS cells. The targets of OR3A4 were predicted using the miRDB database. The binding between OR3A4 and miRNAs was confirmed by dual-luciferase reporter assay.

Results

OR3A4 was overexpressed in OS tissues and correlated with the advanced progression of OS patients. Down-regulation of OR3A4 significantly inhibited the proliferation and colony formation of OS cells. Mechanistically, OR3A4 acted as a sponge of miR-1207-5p. Glucose-6-phosphate dehydrogenase (G6PD) was identified as a target of miR-1207-5p. Knockdown of OR3A4 increased the expression of miR-1207-5p and consequently, suppressed the level of G6PD in OS cells. Due to the essential role of G6PD in the pentose phosphate pathway (PPP), depletion of OR3A4 inhibited NADPH production, glucose consumption and lactate generation. Decreased level of NADPH by depletion of OR3A4 up-regulated the redox state (ROS) content and resulted in endoplasmic reticulum (ER) stress in OS cells. Restoration of G6PD significantly attenuated the cell growth inhibition induced by OR3A4 knockdown.

Conclusion

Our finding suggested the critical role of OR3A4 in the proliferation of OS cells via targeting the miR-1207-5p/G6PD axis.

Signatures of circulating microRNA in four sarcoma subtypes

Background: Sarcomas are rare malignant tumors of mesenchymal origin. The discovery of circulating biomarkers with high diagnostic value could supplement diagnosis of this heterogenous group of tumors. The aim of this study was to identify the profiles of circulating miRNA (c-miRNAs) in four groups of common bone and soft tissue sarcomas.

Methods: At the time of diagnosis, blood samples were collected from 86 patients: 36 with locally advanced/unresectable/metastatic gastrointestinal stromal tumor (GIST) who received first-line treatment with imatinib; 16 with locally advanced osteosarcoma (OS); 26 with locally advanced synovial sarcoma (SS); and eight with locally advanced Ewing sarcoma (ES). In addition, samples were collected from 30 healthy controls. C-miRNAs were isolated using a miRCURY RNA Isolation Kit, followed by preparation of cDNA libraries and sequencing on the Ion Proton platform.

Results: Pair-wise comparisons identified 156 unique c-miRNAs (adjusted P-value < 0.05) showing significant dysregulation between controls and patients; of these, 24, 36, 42, and 99 differentiated controls from pretherapeutic OS, SS, ES, and GIST, respectively. Ten c-miRNAs were commonly altered in at least three sarcoma types. Receiver operating characteristic curves and area under the curve (ROC-AUC) analyses revealed that a four-miRNA diagnostic classifier was able to differentiate controls from ES, GIST, OS, and SS, with AUC-ROC values of 1, 0.97, 0.95, and 0.94, respectively.

Conclusions: Aberrant miRNA expression signatures were identified in serum from patients with four different sarcoma subtypes. Differences in miRNA expression profiles between sarcoma patients and healthy volunteers suggest that miRNAs may play a role in sarcoma development.

miR-125a suppresses malignancy of multiple myeloma by reducing the deubiquitinase USP5

miR-125a is a microRNA that is frequently diminished in various human malignancies. However, the mechanism by which impaired miR-125a promotes cancer growth remains undefined. In this study, we investigated the role of miR-125a in the proliferation and apoptosis of multiple myeloma (MM). To do this, we used MM tissue samples (from 40 anonymous patients), normal matched control samples, and five MM-derived cell lines. We also established a mouse model of MM xenograft to explore the effect of overexpression of miR-125a on the MM growth in vivo. Quantitative real-time polymerase chain reaction revealed that the miR-125a expression was broadly reduced in MM tissues and cell lines. The impairment of miR-125a in MM tissues was functionally relevant because the overexpression of miR-125a remarkably decreased the cell viability and colony-forming activity, at least in part, by promoting apoptosis in two miR-125a-deficient MM cell lines: NCI-H929 and U266. Interestingly, we also discovered that the human gene encoding the ubiquitin-specific peptidase 5 (USP5), which is known to promote cellular deubiquitination and ubiquitin/proteasome-dependent proteolysis, was a direct transcriptional target for miR-125a to repress. More importantly, the heterologous expression of USP5 significantly reversed the growth-inhibitory effects of miR-125a on MM cells in vitro. In the mouse xenograft model, overexpressed miR-125a prominently inhibited the growth of MM tumors and concomitantly reduced the expression of USP5 in tumor tissues. These results suggest that miR-125a inhibits the expression of USP5, thereby mitigating the proliferation and survival of malignant MM cells. We propose that USP5 acts as an oncoprotein in miR-125a-missing cancers.

Role of miR-142 in the pathogenesis of osteosarcoma and its potential as therapeutic approach

Osteosarcoma (OS) is the most common primary malignant tumor of the bone with a strong tendency to early metastasis, and occurs in growing bones more commonly in children and adolescents. Considering the limited therapeutic methods and lack of 100% success of these methods, developing innovative therapies with high efficacy and lower side effects is needed. Meanwhile, miRNAs and the studies indicating the involvement of miRNAs in OS development have attracted attentions as a result of the frequent abnormalities in expression of miRNAs in cancer. miRNAs are noncoding short sequences with lengths ranging from 18 to 25 nucleotides that play a very important role in cellular processes, such as proliferation, differentiation, migration, and apoptosis. MiRNAs can have either oncogenic or tumor suppressive role based on cellular function and targets. This review aimed to have overview on miR-142 as a tumor suppressor in OS. Moreover, the genes involved in the disease, such as RAC1, HMAG1, MMP9, MMP2, and E-cadherin, which have irregularities as a result of change in miR-142 expression, and, thereby, result in increasing the proliferation, invasion, and metastasis of the cells in the tissues and OS cells will be discussed.

MiR-216b inhibits osteosarcoma cell proliferation, migration, and invasion by targeting Forkhead Box M1

Osteosarcoma (OS) is considered the most common type of primary malignant bone tumor, which has a high rate of mortality in children and adolescents. However, the current treatment methods for OS are ineffective. Therefore, there is an urgent requirement to identify the critical targets. This study aimed to identify the roles and significance of microRNA-216b (miR-216b) in OS. To explore the cellular and molecular functions of miR-216b and Forkhead Box M1 (FoxM1) in OS, the expression of miR-216b and FoxM1 at the transcriptional level was measured using quantitative real-time PCR (qRT-PCR). Wound healing assay, 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyltetrazolium bromide assay (MTT) assay, flow cytometry, and transwell invasion assay were conducted to study the function of miR-216b and FoxM1 in OS cells. Dual luciferase reporter assay was performed to identify the relationships between miR-216b and FoxM1. qRT-PCR results revealed that miR-216b expression was significantly downregulated, and FoxM1 was observed to be significantly upregulated in human OS cell lines (MG-63) and tissues. MTT data showed that upregulation of miR-216b expression led to cell growth inhibition in MG-63 cells. The results of the invasion assay and wound healing assay illustrated that miR-216b upregulation or FoxM1 downregulation could inhibit the invasion and migration in MG-63 cells. In vivo, the tumor volume was significantly decreased by miR-194 mimic treatment compared with the control group. Furthermore, the results of the luciferase assay indicated that FoxM1 is a direct target of miR-216b. These findings may provide novel insights into the molecular mechanism of miR-216b and FoxM1 in the progression of OS, and suggested that miR-216b may serve as a potential tumor inhibitor of OS by targeting FoxM1.

Dysregulation of KCNQ1OT1 promotes cholangiocarcinoma progression via miR-140-5p/SOX4 axis

It is commonly recognized that aberrant expression of long non-coding RNAs (lncRNAs) is an important cause of cancer progression. The oncogenic property of KCNQ1OT1 has been identified in several malignant tumors. Here, we decided to explore the biological function and molecular mechanism of KCNQ1OT1 in cholangiocarcinoma (CCA). The expression conditions of KCNQ1OT1 in different tissues and cell lines were examined with qRT-PCR analysis. As expected, KCNQ1OT1 was highly expressed in CCA tissues and cell lines. Results of functional assays revealed the oncogenic function of KCNQ1OT in cholangiocarcinoma progression. The positive effect of KCNQ1OT1 on cell proliferation, invasion and epithelial-mesenchymal transition was identified by performing MTT assay, colony formation assay, transwell invasion assay and western blotting. Whereas, the negative effect of KCNQ1OT1 on the cell apoptosis was tested with flow cytometry analysis. Mechanism investigation revealed that KCNQ1OT1 can act as a ceRNA to improve CCA progression by regulating miR-140-5p/SOX4 axis. Recue assays were conducted to demonstrate the actual effects of KCNQ1OT1-miR-140-5p-SOX4 pathway on CCA progression.

Prognostic value of microRNAs in osteosarcoma: A meta-analysis

BACKGROUND

Osteosarcoma is the most common primary bone malignancy. We meta-analyzed the prognostic value of altered miRNAs in patients with osteosarcoma.

METHODS

Sources from MEDLINE (from inception to August 2016) and EMBASE (from inception to August 2016) were searched. Studies of osteosarcoma with results of miRNA and studies that reported survival data were included and two authors performed the data extraction independently. Any discrepancies were resolved by a consensus. The outcome was overall survival and event-free survival assessed using hazard ratios (HRs).

RESULTS

After reviewing the full text of 65 articles, 25 studies including 2,278 patients were eligible in this study. The pooled HR for deaths was 1.40 (95% confidence interval [CI] 1.01-1.94, p=0.04) with random-effects model (χ2=113.08, p<0.00001, I2=79%) for patients of osteosarcoma with lower expression of miRNA. However, the pooled HR for events was not significant (HR 0.97, 0.63-1.48, p=0.87, χ2=72.65, p<0.00001, I2=79%). In pathway analysis of miRNAs, miRNA449a, 199-5p, 542-5p have common target genes.

CONCLUSIONS

Expression level of miRNA in patients of osteosarcoma is important as a prognostic factor.

Small non-coding RNAs-based bone regulation and targeting therapeutic strategies

Small non-coding RNAs, which are 20-25 nucleotide ribonucleic acids, have emerged as an important transformation in the biological evolution over almost three decades. microRNAs (miRNAs) and short interfering RNAs (siRNAs) are two significant categories of the small RNAs that exert important effects on bone endocrinology and skeletology. Therefore, clarifying the expression and function of these important molecules in bone endocrine physiology and pathology is of great significance for improving their potential therapeutic value for metabolism-associated bone diseases. In the present review, we highlight the recent advances made in understanding the function and molecular mechanism of these small non-coding RNAs in bone metabolism, especially their potentially therapeutic values in bone-related diseases.

MicroRNAs and Fracture Healing

MicroRNAs (miRNAs) are small molecules found to have major regulatory roles in many biological processes. This review aims to provide an overview of the recent advances in knowledge of the role of miRNAs in fracture healing and bone repair. A search of the published literature was performed (using the PubMed database) to include all relevant studies published in English. These studies were then reviewed and the results condensed into this review paper. MiRNAs have now been shown to have significant alterations in expression levels in bone tissue in the presence of fractures. This is thought to be related to the process of fracture healing through effects on osteoblasts and bone growth factors. These small molecules are also detectable in the circulation where their expression appears to be altered by the presence of fractures. Although further research is required in this area, miRNAs may present an opportunity for future clinical applications in fracture management.

MicroRNA-195 inhibits growth and invasion of laryngeal carcinoma cells by directly targeting DCUN1D1

MicroRNAs (miRNAs) are a class of small, non-coding RNAs that regulate gene expression and are involved in cell biological processes. The aberrant expression of miR-195 has been found in various types of human cancer. However, the effect of miR-195 on the initiation and development of laryngeal squamous cell carcinoma (LSCC) remains to be elucidated. Accordingly, in the present study, we detected the expression level of miR-195 in the LSCC and the normal tissues and found that miR-195 were significantly downregulated in the LSCC tissues. Gain-of-function or loss-of-function studies including cell proliferation, wound healing assay, Transwell assay, cell cycle and apoptosis assays were performed to investigate the biological function of miR-195. Luciferase reporter assay and the rescue study confirmed that DCUN1D1 was a target of miR-195. Furthermore, DCUN1D1 expression levels were found to be upregulated in laryngeal tissues and to have a negative correlation with miR-195. We also found that both miR-195 and DCUN1D1 siRNAs can inhibit cell invasion possibly through downregulating Matrix metalloproteinase-2 (MMP-2) and Matrix metalloproteinase-9 (MMP-9) at the post-transcriptional level, which can be attenuated by restoring the expression of DCUN1D1. In summary, these data suggest that low expression of miR-195 contributes to the poor prognosis of LSCC and miR-195 regulates the proliferation and invasion ability of LSCC cells in vitro. miR-195 may suppress growth and invasion of LSCC cells possibly through targeting DCUN1D1, which would provide a candidate target for cancer therapy.

miR-1247-5p functions as a tumor suppressor in human hepatocellular carcinoma by targeting Wnt3

Increasing evidence suggests that aberrant expression of certain microRNAs (miRNAs) may participate in the genesis and progression of tumors. Several studies have indicated that miR-1247-5p plays different roles in various types of cancer cells. The effects of miR-1247-5p on human hepatocellular carcinoma (HCC) cells are elusive. In the present study, we investigated the effects of miR-1247-5p on the progression of HCC. The transcript of miR-1247-5p was markedly downregulated in clinical samples of patients with HCC and HCC cell lines, and ectopic overexpression of miR‑1247-5p markedly inhibited the proliferation and invasion of HepG2 cells, induced cell apoptosis in vitro, and suppressed the growth of transplanted tumors in vivo. Wnt3 was found to be a potential target of miR-1247-5p and overexpression of miR-1247-5p was able to significantly downregulate the expression of Wnt3 by directly targeting the 3'UTR of this gene, which was verified by luciferase reporter assay and western blotting. Furthermore, we found that the miR-1247-5p gene was hypermethylated in HepG2 cells, and the transcript of miR-1247-5p was increased significantly after treatment with the demethylation drug 5-azacytidine. These findings demonstrated that miR-1247-5p functions as a tumor suppressor in human HCC by targeting Wnt3 and that the expression of miR-1247-5p can be regulated by DNA methylation, which indicates that miR-1247-5p has the potential to be a therapeutic target as well as a diagnostic marker of HCC.

Knockdown of long non-coding RNA HOTAIR increases miR-454-3p by targeting Stat3 and Atg12 to inhibit chondrosarcoma growth

Current practices for the therapy of chondrosarcoma, including wide-margin surgical resection and chemotherapy, are less than satisfactory. Recently, emerging evidence has demonstrated that long non-coding RNAs (lncRNAs) have an essential role in the initiation and progression of tumors. As a typical lncRNA, HOTAIR is significantly overexpressed in various tumors. However, the function and potential biological mechanisms of HOTAIR in human chondrosarcoma remain unknown. Quantitative RT-PCR demonstrated that HOTAIR expression was upregulated in chondrosarcoma tissues and cell lines. High HOTAIR expression is correlated with tumor stage and poor prognosis. Functional experiments reveal that HOTAIR knockdown leads to growth inhibition of human chondrosarcoma cells in vitro and in vivo. In addition to cycle arrest and apoptosis, knockdown of HOTAIR inhibits autophagy, which favors cell death. Mechanistically, we demonstrated that HOTAIR induced DNA methylation of miR-454-3p by recruiting EZH2 and DNMT1 to the miR-454-3p promoter regions, which markedly silences miR-454-3p expression. Further analysis revealed that STAT3 and ATG12 are targets of miR-454-3p, initiate HOTAIR deficiency-induced apoptosis and reduce autophagy. Collectively, our data reveal the roles and functional mechanisms of HOTAIR in human chondrosarcoma and suggest that HOTAIR may act as a prognostic biomarker and potential therapeutic target for chondrosarcoma.

MiR-9 is overexpressed in spontaneous canine osteosarcoma and promotes a metastatic phenotype including invasion and migration in osteoblasts and osteosarcoma cell lines

Background

MicroRNAs (miRNAs) regulate the expression of networks of genes and their dysregulation is well documented in human malignancies; however, limited information exists regarding the impact of miRNAs on the development and progression of osteosarcoma (OS). Canine OS exhibits clinical and molecular features that closely resemble the corresponding human disease and it is considered a well-established spontaneous animal model to study OS biology. The purpose of this study was to investigate miRNA dysregulation in canine OS.

Methods

We evaluated miRNA expression in primary canine OS tumors and normal canine osteoblast cells using the nanoString nCounter system. Quantitative PCR was used to validate the nanoString findings and to assess miR-9 expression in canine OS tumors, OS cell lines, and normal osteoblasts. Canine osteoblasts and OS cell lines were stably transduced with pre-miR-9 or anti-miR-9 lentiviral constructs to determine the consequences of miR-9 on cell proliferation, apoptosis, invasion and migration. Proteomic and gene expression profiling of normal canine osteoblasts with enforced miR-9 expression was performed using 2D-DIGE/tandem mass spectrometry and RNA sequencing and changes in protein and mRNA expression were validated with Western blotting and quantitative PCR. OS cell lines were transduced with gelsolin (GSN) shRNAs to investigate the impact of GSN knockdown on OS cell invasion.

Results

We identified a unique miRNA signature associated with primary canine OS and identified miR-9 as being significantly overexpressed in canine OS tumors and cell lines compared to normal osteoblasts. Additionally, high miR-9 expression was demonstrated in tumor-specific tissue obtained from primary OS tumors. In normal osteoblasts and OS cell lines transduced with miR-9 lentivirus, enhanced invasion and migration were observed, but miR-9 did not affect cell proliferation or apoptosis. Proteomic and transcriptional profiling of normal canine osteoblasts overexpressing miR-9 identified alterations in numerous genes, including upregulation of GSN, an actin filament-severing protein involved in cytoskeletal remodeling. Lastly, stable downregulation of miR-9 in OS cell lines reduced GSN expression with a concomitant decrease in cell invasion and migration; concordantly, cells transduced with GSN shRNA demonstrated decreased invasive properties.

Conclusions

Our findings demonstrate that miR-9 promotes a metastatic phenotype in normal canine osteoblasts and malignant OS cell lines, and that this is mediated in part by enhanced GSN expression. As such, miR-9 represents a novel target for therapeutic intervention in OS.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2837-5) contains supplementary material, which is available to authorized users.

Induction of the mesenchymal to epithelial transition by demethylation-activated microRNA-125b is involved in the anti-migration/invasion effects of arsenic trioxide on human chondrosarcoma

Background

In addition to treating acute promyelocytic leukemia, arsenic trioxide (ATO) suppresses other solid tumors, including chondrosarcoma. However, the effects of ATO on metastasis in chondrosarcoma cells, and the underlying molecular mechanisms remain unclear.

Methods

The effects of ATO on the migratory and invasive capacities of chondrosarcoma cells were investigated by Wound healing, Transwell and EMT assays. The expression of miR-125b in human chondrosarcoma tissues and cell lines was detected by real-time PCR analysis. Bisulfite sequencing analysis (BSP) was used to detect the effects of ATO on the expression of miR-125b. The gain-of-function and loss-of-function experiments were performed on chondrosarcoma cell lines to investigate the effects of miR-125b on chondrosarcoma invasion, and to determine whether signal transducer and activator of transcription 3(Stat3) mediates these effects. Dual-luciferase reporter assay was used to identify whether Stat3 is a direct target of miR-125b.

Results

MiR-125b was significantly downregulated in human metastatic chondrosarcoma tissues and cell lines but not in non-metastatic chondrosarcoma tissues. ATO up-regulates the expression of miR-125b by the demethylation of DNA. ATO induces MET and attenuates the invasive capacities of chondrosarcoma cells through miR-125b. Stat3 was verified as a direct target of miR-125b, which is involved in ATO regulating EMT-associated traits.

Conclusions

These findings, for the first time, provides evidence that the miR-125b-mediated inhibition of Stat3 is involved in the ATO-induced attenuation of metastasis in chondrosarcoma cells.

miR-106a-5p Suppresses the Proliferation, Migration, and Invasion of Osteosarcoma Cells by Targeting HMGA2

We aim to investigate the effect of miR-106a-5p on the proliferation, migration, and invasion of osteosarcoma (OS) cells by targeting high-mobility group AT-hook 2 (HMGA2). Real-time fluorescent quantitative polymerase chain reaction (RT-qPCR) was used for detecting the expressions of miR-106-5p and HMGA2 in 137 OS and adjacent normal bone tissues. Immunohistochemistry was applied for the HMGA2 protein expression detection. Luciferase reporter gene assay was conducted for verifying whether miR-106-5p targeted HMGA2. MG63 and U2SO cells were respectively divided into five groups: Blank, miR-106a-5p, scramble, HMGA2-siRNA, and miR-106a-5p+HMGA2 groups. RT-qPCR and western blot were applied for detecting the expressions of miR-106a-5p and HMGA2 in five groups. Proliferation rate, cell cycle, invasion, and migration ability of OS cells were detected using methyl thiazolyl-tetrazolium, 5-ethynyl-2'-deoxyuridine (Edu) assay, flow cytometry, and Transwell.  Compared with adjacent normal tissues, OS tissues presented with decreased miR-106a-5p expressions, elevated HMGA2 mRNA, and positive expressions (all p < 0.05). The sensitivity and specificity of miR-106a-5p were 97.8%, 93.43%, and HMGA2 mRNA were 97.8%, 99.27%, separately. miR-106a-5p and HMGA2 expressions were associated with tumor size, Enneking stage, distant metastasis, and lung metastasis. Expressions of HMGA2 in OS cells in miR-106a-5p and HMGA2 siRNA groups were both significantly decreased with the same downregulation level, and the proliferation rates in both groups were obviously slowed down after 48 h (both p < 0.001). Edu positive cells, S phase cells (majority of cells blocked at G0/G1 phase), migratory and invasive cells were obviously decreased (all p < 0.05). Downregulation of miR-106a-5p was found in OS tissues, and upregulation of miR-106a-5p can inhibit the proliferation, migration, and invasion by targeting HMGA2 in OS cells.

miR-148a and miR-375 may serve as predictive biomarkers for early diagnosis of laryngeal carcinoma

The role of microRNAs (miRs) as possible biomarkers and therapy targets has been extensively investigated in a number of types of cancer. However, the aberrant expression of miRs in laryngeal squamous cell carcinoma (LSCC), particularly during the progression of the disease, is poorly understood. In the present study, the role of miRs as possible novel early pre-diagnostic biomarkers of LSCC was investigated. TaqMan probe stem-loop quantitative polymerase chain reaction was utilized to accurately measure the amount of miR-148a and miR-375 in clinical samples of mild dysplasia, moderate dysplasia, severe dysplasia, cancer in situ, laryngeal cancer and normal epithelial controls. The application of miR-148a and miR-375 as potential predictive biomarkers for early diagnosis of LSCC was analyzed. The results of the present study suggested that miR-148a and miR-375 were significantly upregulated in LSCC tissues, and increased expression of miR-375 was associated with a more aggressive phenotype of LSCC. Additional investigation revealed that miR-148a and miR-375 increased during different dysplasia stages of LSCC carcinogenesis, and high-level expression of miR-148a or miR-375 in patients with laryngeal dysplasia may predict subsequent malignant transformation. miR-148a and miR-375 were significantly upregulated during LSCC carcinogenesis and may serve as possible predictive biomarkers for early diagnosis of LSCC.

microRNA and Bone Cancer

MicroRNA molecules have a variety of roles in cellular development and proliferation processes, including normal osteogenesis. These effects are exerted through post-translational inhibition of target genes. Altered miRNA expression has been demonstrated in several cancers, both in the tumor tissue and in the peripheral circulation. This may influence carcinogenesis if the specific miRNA targets are encoded by tumor suppressor genes or oncogenes. To date, most research investigating the role of microRNAs and primary bone tumors has focused on osteosarcoma and Ewing sarcoma. Several microRNAs including the miR-34 family have been implicated in osteosarcoma tumorigenesis via effects on the Notch signaling pathway. Progression, invasion, and metastasis of osteosarcoma tumor cells is also influenced by microRNA expression. In addition, microRNA expression may affect the response to chemotherapy in osteosarcoma and thus hold potential for future use as either a prognostic indicator or a therapeutic target. The EWS-FLI1 fusion protein produced in Ewing sarcoma has been shown to induce changes in miRNA expression. MicroRNA expression profiling may have some potential for prediction of disease progression and survival in Ewing sarcoma. There is limited evidence to support a role for microRNAs in other primary bone tumors, either malignant or benign; however, early work is suggestive of involvement in chondrosarcoma, multiple osteochondromatosis, and giant cell tumors of bone.

MicroRNAs: exploring new horizons in osteoarthritis

INTRODUCTION

Osteoarthritis (OA) is a common disease worldwide leading to significant morbidity. The underlying disease process is multifactorial however there is increasing focus on molecular mechanisms. MicroRNAs are small non-coding segments of RNA that have important regulatory functions at a cellular level. These molecules are readily detectable in human tissues and circulation. They are increasingly recognised as having a major role in many disease processes - including malignancy and inflammatory processes.

OBJECTIVE

This review paper aims to provide a comprehensive update on the evidence for miRNA roles in OA.

DESIGN

A comprehensive literature search was performed using key medical subject headings (MeSH) terms 'microRNA' and 'osteoarthritis'.

RESULTS

Several miRNAs have been identified as having aberrant expression levels in OA. Some of these include miR-9, miR-27, miR-34a, miR-140, miR-146a, miR-558 and miR-602. Many of the dysregulated miRNAs have been shown to regulate expression of inflammatory pathways such as interleukin-mediated or matrix metalloproteinase-13 (MMP-13)-mediated degradation of the articular cartilage extracellular matrix (ECM). MiRNAs may also play a role in pain pathways and hence expression of clinical symptoms.

CONCLUSIONS

Recent evidence has shown that miRNAs in the circulation may reflect underlying disease states and hence serve as potential markers for disease activity. These findings may represent possible future therapeutic applications in the management of OA.

MicroRNA-26a induces osteosarcoma cell growth and metastasis via the Wnt/β-catenin pathway

MicroRNAs (miRNAs/miRs) are a type of highly conserved, small non-coding RNA that are vital to the post-transcriptional regulation of gene expression via base pairing with target mRNA 3'-untranslated regions (3'-UTRs). Several studies have indicated that the abnormal expression of miRNAs occurs frequently in human osteosarcoma (OS). In the present study, the role of miR-26a in the progression and metastasis of OS was investigated using reverse transcription-quantitative polymerase chain reaction, a luciferase activity assay, cell viability assay, in vitro migration and invasion assays, transfection and western blot analysis. miR-26a was upregulated in OS tissues and cell lines, and the expression of miR-26a was indicated to affect the proliferation, migration and invasion of OS Saos-2 cells. At the molecular level, the results showed that glycogen synthase kinase-3β (GSK-3β) was identified as a target of miR-26a, and the ectopic expression of miR-26a inhibited GSK-3β by directly binding to the 3'-UTR. Therefore, the expression of miR-26a was negatively correlated with GSK-3β in the OS tissues. These data suggest that miR-26a is significant in the proliferation of human OS cells due to the direct regulation of Wnt/β-catenin signaling.

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.

MicroRNA-299-3p promotes the sensibility of lung cancer to doxorubicin through directly targeting ABCE1

MicroRNAs (miRNAs) are a class of endogenous, small non-coding RNAs which play important roles in various biological and cellular processes, including chemoresistance. The expression level of miR-299-3p was dysregulated in doxorubicin-resistance lung cancer cell lines. However, the exact role of miR-299-3p in doxorubicin-resistance is still unknown. In the present study, miR-299-3p was down-expressed in doxorubicin-resistant or -sensitive lung cancer samples and it was identified to directly targeted adenosine triphosphate binding cassette E1 (ABCE1) 3'-untranslated region (UTR) in lung cancer H69 cells by luciferase assay. After transfection of miR-299-3p mimics or ABCE1-siRNA, MTT assay confirmed that the H69/ADR cell proliferation was inhibited, as well as the enhanced cell inhibitory rate in the presence of doxorubicin. H69/ADR cell apoptosis rate was promoted after miR-299-3p or ABCE1-siRNA transfection. The results indicated that miR-299-3p promotes the sensibility of lung cancer to doxorubicin through suppression of ABCE1, at least partly. Therefore, the disordered decreased of miR-299-3p and resulting ABCE1 up-expression may contribute to chemoresistance of lung cancer, and miR-299-3p-ABCE1 may represent a new potential therapeutic target for the treatment of chemoresistance of lung cancer.

Biomarkers of Brain Damage and Postoperative Cognitive Disorders in Orthopedic Patients: An Update

The incidence of postoperative cognitive dysfunction (POCD) in orthopedic patients varies from 16% to 45%, although it can be as high as 72%. As a consequence, the hospitalization time of patients who developed POCD was longer, the outcome and quality of life were worsened, and prolonged medical and social assistance were necessary. In this review the short description of such biomarkers of brain damage as the S100B protein, NSE, GFAP, Tau protein, metalloproteinases, ubiquitin C terminal hydrolase, microtubule-associated protein, myelin basic protein, α-II spectrin breakdown products, and microRNA was made. The role of thromboembolic material in the development of cognitive decline was also discussed. Special attention was paid to optimization of surgical and anesthetic procedures in the prevention of postoperative cognitive decline.

Bone microenvironment signals in osteosarcoma development

The bone is a complex connective tissue composed of many different cell types such as osteoblasts, osteoclasts, chondrocytes, mesenchymal stem/progenitor cells, hematopoietic cells and endothelial cells, among others. The interaction between them is finely balanced through the processes of bone formation and bone remodeling, which regulates the production and biological activity of many soluble factors and extracellular matrix components needed to maintain the bone homeostasis in terms of cell proliferation, differentiation and apoptosis. Osteosarcoma (OS) emerges in this complex environment as a result of poorly defined oncogenic events arising in osteogenic lineage precursors. Increasing evidence supports that similar to normal development, the bone microenvironment (BME) underlies OS initiation and progression. Here, we recapitulate the physiological processes that regulate bone homeostasis and review the current knowledge about how OS cells and BME communicate and interact, describing how these interactions affect OS cell growth, metastasis, cancer stem cell fate and therapy outcome.

MicroRNAs as potential target in human bone and soft tissue sarcoma therapeutics

Sarcomas are highly aggressive heterogeneous tumors that are mesenchymal in origin. There have been vast advancements on identifying diagnostic markers for sarcomas including chromosomal translocations, but very little progress has been made to identify targeted therapies against them. The tumor heterogeneity, genetic complexity and the lack of drug studies make it challenging to recognize the potential targets and also accounts for the inadequate treatments in sarcomas. In recent years, microRNAs that are a part of small non-coding RNAs have shown promising results as potential diagnostic and prognostic biomarkers in multiple sarcoma types. This review focuses on the current knowledge of the microRNAs that are deregulated in sarcomas, and an insight on the strategies to target these microRNAs that are essential for developing improved therapies for various human sarcomas.

Overexpression of miR‑199b‑5p inhibits Ewing's sarcoma cell lines by targeting CCNL1

MicroRNAs (miRNAs) are known to regulate the expression of a variety of genes, which are important in the development of several types of tumor, including Ewing's sarcoma (ES), at the post‑transcriptional level. Although previous studies have identified that the expression of miRNA‑199b‑5p was downregulated in various types of tumor, the expression levels of miR‑199b‑5p in ES cells remain to be elucidated. The mechanism underlying ES via the miRNA pathway remains to be elucidated. The present study demonstrated that miR‑199b‑5p was an important regulator in ES cells and its expression was downregulated in ES originated A673/TC252 cells. The ES cell lines, A673 and TC252, were transfected with an miR‑199b‑5p mimic to overexpress the levels of this miRNA. This forced expression of miR‑199b‑5p suppressed the cell proliferation and invasion, arrested cell cycle progression, and promoted cell apoptosis. Furthermore, CCNL1 was identified by bioinformatic software as a potential target gene of miR‑199b‑5p. Following this, the present study identified CCNL1 as a direct target of miR‑199b‑5p in ES cells. Taken together, the present study established a functional link between ES, miR‑199b‑5p and CCNL1, and suggested that miR‑199b‑5p acts as a tumor suppressor and may be of diagnostic and therapeutic importance for human ES.

MicroRNA-375 functions as a tumor suppressor in osteosarcoma by targeting PIK3CA

Osteosarcoma has become one of the most common primary malignant bone tumors in childhood and adult. Numerous studies have demonstrated that aberrant microRNA (miRNA) expression is involved in human disease including cancer. To date, the potential miRNAs regulating osteosarcoma growth and progression are not fully identified yet. Herein, we showed that miR-375 was frequently downregulated in osteosarcoma tissue and cell lines compared to normal human colon tissues. Overexpression of miR-375 resulted in decreased expression of PIK3CA (phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha) at both mRNA and protein levels. We found that miR-375 overexpression markedly suppressed cell proliferation in vitro. And inhibition of miR-375 promotes osteosarcoma growth. Mechanistic studies showed that PIK3CA was a potential target of miR-375 and it mediated reduction of PIK3CA resulted in suppression of PI3K/Akt pathway. Taken together, our results demonstrate that miR-375 functions as a growth-suppressive miRNA and plays an important role in inhibiting the tumorigenesis through targeting PIK3CA in osteosarcoma.

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.