MicroRNA-198 inhibited tumorous behaviors of human osteosarcoma through directly targeting ROCK1

The Landscape of microRNAs in Bone Tumor: A Comprehensive Review in Recent Studies

Cancer, the second greatest cause of mortality worldwide, frequently causes bone metastases in patients with advanced-stage carcinomas such as prostate, breast, and lung cancer. The existence of these metastases contributes to the occurrence of skeletal-related events (SREs), which are defined by excessive pain, pathological fractures, hypercalcemia, and spinal cord compression. These injurious incidents leave uncomfortably in each of the cancer patient's life quality. Primary bone cancers, including osteosarcoma (OS), chondrosarcoma (CS), and Ewing's sarcoma (ES), have unclear origins. MicroRNA (miRNA) expression patterns have been changed in primary bone cancers such as OS, CS, and ES, indicating a role in tumor development, invasion, metastasis, and treatment response. These miRNAs are persistent in circulation and exhibit distinct patterns in many forms of bone tumors, making them potential biomarkers for early detection and treatment of such diseases. Given their crucial regulatory functions in various biological processes and conditions, including cancer, this study aims to look at miRNAs' activities and possible contributions to bone malignancies, focusing on OS, CS, and ES. In conclusion, miRNAs are valuable tools for diagnosing, monitoring, and predicting OS, CS, and ES outcomes. Further research is required to fully comprehend the intricate involvement of miRNAs in these bone cancers and to develop effective miRNA-based treatments.

circ_0002060 Enhances Doxorubicin Resistance in Osteosarcoma by Regulating the miR-198/ABCB1 Axis

Background: Osteosarcoma (OS) is a common, aggressive primary sarcoma of bone. Drug resistance is a huge obstacle to chemotherapy for cancer. This study aimed to investigate the role and mechanism of circ_0002060 in OS resistance to doxorubicin (DOX). Methods: The levels of circ_0002060, miR-198, and ATP-binding cassette subfamily B member 1 (ABCB1) in OS tissues and DOX-resistant OS cells were measured by quantitative real-time polymerase chain reaction or Western blot assay. Kaplan-Meier analysis was performed to determine the relationship between circ_0002060 expression in OS tissues and overall survival of OS patients. The half-inhibitory concentration (IC50) of DOX was calculated using the Cell Counting Kit-8 (CCK-8) assay. Proliferation and apoptosis of DOX-resistant OS cells were assessed by colony formation assay and flow cytometry. The levels of apoptosis-related proteins in DOX-resistant OS cells were measured by Western blot assay. Xenograft assay was utilized to analyze the effect of circ_0002060 on DOX resistance in vivo. The interactions among circ_0002060, miR-198, and ABCB1 in DOX-resistant OS cells were confirmed by dual-luciferase reporter assay, RNA immunoprecipitation assay, or RNA pull-down assay. Results: circ_0002060 and ABCB1 were upregulated, while miR-198 was downregulated in OS tissues and DOX-resistant OS cells. circ_0002060 silencing reduced DOX resistance in vitro and in vivo. Moreover, circ_0002060 enhanced DOX resistance by sponging miR-198. Besides, miR-198 decreased DOX resistance by binding to ABCB1. In addition, circ_0002060 sponged miR-198 to upregulate ABCB1 expression. Conclusions: circ_0002060 promoted DOX resistance and OS progression by regulating the miR-198/ABCB1 axis, suggesting that circ_0002060 might be a promising biomarker for OS therapy.

Silencing of circ-CDK14 suppresses osteosarcoma progression through the miR-198/E2F2 axis

BACKGROUND

Osteosarcoma (OS) is the most common primary bone malignancy. Circular RNAs (circRNAs) have been implicated in OS pathogenesis. In the current study, we explored the precise role of circRNA cyclin dependent kinase 14 (circ-CDK14, hsa_circ_0001721) in OS progression.

METHODS

The levels of circ-CDK14, miR-198 and E2F transcription factor 2 (E2F2) were evaluated by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot. Cell viability, apoptosis, migration and invasion were determined using the Cell Counting-8 Kit (CCK-8), flow cytometry and transwell assays, respectively. Glucose consumption, lactate production and adenosine triphosphate (ATP) level were gauged using the commercial assay kits. The direct relationship between miR-198 and circ-CDK14 or E2F2 was confirmed by dual-luciferase reporter, RNA pull-down and RNA immunoprecipitation (RIP) assays. Animal studies were used to analyze the role of circ-CDK14 in vivo.

RESULTS

Our data revealed that circ-CDK14 was up-regulated and miR-198 was down-regulated in OS tissues and cell lines. Circ-CDK14 silencing suppressed OS cell viability, migration, invasion, and glycolysis and promoted cell apoptosis in vitro, as well as diminished tumor growth in vivo. Mechanistically, circ-CDK14 directly targeted miR-198. Moreover, miR-198 was a functional mediator of circ-CDK14 in regulating OS cell progression in vitro. E2F2 was a direct target of miR-198, and miR-198 overexpression regulated OS cell progression in vitro by down-regulating E2F2. Furthermore, circ-CDK14 regulated E2F2 expression by functioning as a sponge of miR-198 in OS cells.

CONCLUSION

Our findings demonstrate the inhibitory effect of circ-CDK14 silencing on OS progression by targeting the miR-198/E2F2 axis, establishing a strong rationale for decreasing circ-CDK14 as a novel therapeutic strategy for OS.

Emerging role and function of miR-198 in human health and diseases

Ever since their discovery, microRNAs (miRNAs/miRs) have astonished us by the plethora of processes they regulate, and thus adding another dimension to the gene regulation. They have been implicated in several diseases affecting cardiovascular, neurodegenerative, hepatic, autoimmune and inflammatory functions. A primate specific exonic miRNA, miR-198 has been vastly studied during the past decade, and shown to have a critical role in wound healing. The aberrant expression of miR-198 was first reported in schizophrenia, linking it to neural development. Later, its dysregulation and tumor suppressive role was reported in hepatocellular carcinoma. However, this was just a beginning, and after which there was an explosion of reports linking miR-198 deregulation to cancers and other ailments. The first target to be identified for miR-198 was Cyclin T1 in monocytes affecting HIV1 replication. Depending on the type of cancer, miR-198 has been shown to function either as a tumor suppressor or an oncomir. Interestingly, miR-198 is not only known to regulate multiple targets and pathways, but also is itself regulated by several circular RNAs and long-non-coding RNAs, highlighting a complex regulatory network. This review highlights the currently understood mechanism and regulation of miR-198 in different diseases, and its possible diagnostic and therapeutic potential.

miR-198 inhibits the progression of renal cell carcinoma by targeting BIRC5

BACKGROUND

miR-198 is involved in the formation, migration, invasion, and metastasis of various malignant cancers. However, the function and mechanism of action of miR-198 in the tumorigenesis of renal cell carcinoma (RCC) remain elusive. Here, we aimed to explore the role of miR198 in RCC.

METHODS

Immunohistochemistry was performed to estimate the level of survivin in RCC sections. Quantitative real-time polymerase chain reaction was performed to determine the expression level of miR-198 in fresh RCC tissues. Furthermore, the target relationship between miR-198 and BIRC5 was predicted using the TargetScanHuman 7.2 database and verified via dual-luciferase reporter assay and western blotting. The effects of miR-198 on the viability, apoptosis, invasion, and migration of A498 and ACHN cells were studied using Cell Counting Kit-8, flow cytometry, transwell migration assay, and wound healing assay, respectively. Additionally, a xenograft nude mouse model was established to evaluate the effect of miR-198 on RCC tumorigenesis.

RESULTS

The expression levels of BIRC5 and miR-198 were respectively higher and lower in RCC tissues than those in normal adjacent tissues. Furthermore, miR-198 could inhibit luciferase activity and reduce the protein level of survivin without affecting the BIRC5 mRNA levels. miR-198 inhibited cell viability, migration, and invasion and promoted cell apoptosis; co-transfection with BIRC5 could rescue these effects. Moreover, miR-198 could repress tumor growth in the xenograft nude mouse model of RCC.

CONCLUSIONS

Our study demonstrates that miR-198 suppresses RCC progression by targeting BIRC5.

Hsa_circ_0010220 regulates miR-198/Syntaxin 6 axis to promote osteosarcoma progression

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hsa_circ_0010220 expression is increased in osteosarcoma.

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hsa_circ_0010220 knockdown represses cell proliferation, migration and invasion.

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hsa_circ_0010220 regulates Syntaxin 6 via miR-198.

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hsa_circ_0010220 silence decreases xenograft tumor growth.

Background

Circular RNAs (circRNAs) are a class of endogenous RNAs that are involved in osteosarcoma progression. Hsa_circ_0010220 (circ_0010220) is a circRNA generated by gene Rho Guanine Nucleotide Exchange Factor 10 Like (ARHGEF10L) and is upregulated in osteosarcoma, but its functional role in osteosarcoma is limited studied. This study aimed to illustrate the regulatory mechanism underlying circ_0010220 in osteosarcoma.

Methods

51 paired tumor and normal tissues were obtained from osteosarcoma patients. circ_0010220, microRNA (miR)-198 and Syntaxin 6 (STX6) abundances were examined by quantitative reverse transcription polymerase chain reaction and western blot. Cell proliferation, cell cycle, apoptosis, migration and invasion were analyzed via Cell Counting Kits-8 (CCK-8), colony formation, flow cytometry and transwell analyses. Target relationship was verified via dual-luciferase reporter analysis, RNA immunoprecipitation and pull-down. The in vivo function was analyzed using a xenograft model.

Results

Circ_0010220 was elevated in osteosarcoma tissues and cells, and was related to the lower survival rate of osteosarcoma patients. Circ_0010220 knockdown inhibited cell proliferation, migration and invasion, but induced cell cycle arrest and apoptosis in vitro. Besides, circ_0010220 silence curbed the growth of xenograft osteosarcoma tumors in vivo. Mechanistic research revealed that miR-198 is a target of circ_0010220, and directly targets STX6. Moreover, circ_0010220 upregulated the expression of STX6 by sponging miR-198 to regulate cell proliferation, migration, invasion, cell cycle, and apoptosis.

Conclusion

Circ_0010220 contributes to osteosarcoma progression through mediating miR-198/STX6 axis, which might be a novel therapeutic target for osteosarcoma therapy.

AHA1 upregulates IDH1 and metabolic activity to promote growth and metastasis and predicts prognosis in osteosarcoma

Osteosarcoma (OS) is the most common primary malignant bone tumor in children and adolescents. Although activator of HSP90 ATPase activity 1 (AHA1) is reported to be a potential oncogene, its role in osteosarcoma progression remains largely unclear. Since metabolism reprogramming is involved in tumorigenesis and cancer metastasis, the relationship between AHA1 and cancer metabolism is unknown. In this study, we found that AHA1 is significantly overexpressed in osteosarcoma and related to the prognosis of osteosarcoma patients. AHA1 promotes the growth and metastasis of osteosarcoma both in vitro and in vivo. Mechanistically, AHA1 upregulates the metabolic activity to meet cellular bioenergetic needs in osteosarcoma. Notably, we identified that isocitrate dehydrogenase 1 (IDH1) is a novel client protein of Hsp90-AHA1. Furthermore, the IDH1 protein level was positively correlated with AHA1 in osteosarcoma. And IDH1 overexpression could partially reverse the effect of AHA1 knockdown on cell growth and migration of osteosarcoma. Moreover, high IDH1 level was also associated with poor prognosis of osteosarcoma patients. This study demonstrates that AHA1 positively regulates IDH1 and metabolic activity to promote osteosarcoma growth and metastasis, which provides novel prognostic biomarkers and promising therapeutic targets for osteosarcoma patients.

MicroRNAs signatures, bioinformatics analysis of miRNAs, miRNA mimics and antagonists, and miRNA therapeutics in osteosarcoma

MicroRNAs (miRNAs) involved in key signaling pathways and aggressive phenotypes of osteosarcoma (OS) was discussed, including PI3K/AKT/MTOR, MTOR AND RAF-1 signaling, tumor suppressor P53- linked miRNAs, NOTCH- related miRNAs, miRNA -15/16 cluster, apoptosis related miRNAs, invasion-metastasis-related miRNAs, and 14Q32-associated miRNAs cluster. Herrin, we discussed insights into the targeted therapies including miRNAs (i.e., tumor-suppressive miRNAs and oncomiRNAs). Using bioinformatics tools, the interaction network of all OS-associated miRNAs and their targets was also depicted.

Targeting ROCK signaling in health, malignant and non-malignant diseases

A Rho-associated coiled-coil kinase (ROCK) is identified as a critical downstream effector of GTPase RhoA which contains two isoforms, ROCK1 (also known as p160ROCK and ROKβ) and ROCK2 (also known as Rho-kinase and ROKα), the gene of which is placed on chromosomes 18 (18q11.1) and 2 (2p24), respectively. ROCKs have a principal function in the generation of actin-myosin contractility and regulation of actin cytoskeleton dynamics. They represent a chief role in regulating various cellular functions, such as apoptosis, growth, migration, and metabolism through modulation of cytoskeletal actin synthesis, and cellular contraction through phosphorylation of numerous downstream targets. Emerging evidence has indicated that ROCKs present a significant function in cardiac physiology. Of note, dysregulation of ROCKs involves in several cardiac pathological processes like cardiac hypertrophy, cardiac fibrosis, systemic blood pressure disorder, and pulmonary hypertension. Moreover, ROCKs, in addition to their role in regulating renal arteriolar contraction, glomerular blood flow, and filtration, can also play a role in controlling podocytes, tubular cells, and mesangial cell structure and function. Hyperactivity disorder and over-gene expression of Rho/ROCK have been indicated in different cancers. Furthermore, it seems that increasing the expression of mRNA or ROCK protein has an undesirable effect on patient survival and has a positive impact on the progression and worsening of disease prognosis. This review focuses on the physiological and pathological functions of ROCKs with a particular view on its possible value of ROCK inhibitors as a new therapy in cancers and non-cancer diseases.

miRNA signatures in childhood sarcomas and their clinical implications

Progresses in multimodal treatments have significantly improved the outcomes for childhood cancer. Nonetheless, for about one-third of patients with Ewing sarcoma, rhabdomyosarcoma, or osteosarcoma steady remission has remained intangible. Thus, new biomarkers to improve early diagnosis and the development of precision-targeted medicine remain imperative. Over the last decade, remarkable progress has been made in the basic understanding of miRNAs function and in interpreting the contribution of their dysregulation to cancer development and progression. On this basis, this review focuses on what has been learned about the pivotal roles of miRNAs in the regulation of key genes implicated in childhood sarcomas.

MicroRNA‑330 is downregulated in retinoblastoma and suppresses cell viability and invasion by directly targeting ROCK1

Abnormal expression of microRNAs (miRNAs/miRs) has been previously reported in various types of human cancer, such as retinoblastoma (RB). Dysregulated miRNAs have been demonstrated to be important epigenetic regulators of numerous biological events associated with RB. Therefore, improved understanding of the precise roles of miRNAs in RB is required to develop novel therapeutic strategies for the treatment of patients with this disease. In the present study, reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) was performed to detect miR‑330 expression in RB tissues and cell lines. The effects of miR‑330 overexpression on the viability and invasion of RB cells were determined using MTT and Matrigel®‑based invasion assays, respectively. The mechanisms underlying the activity of miR‑330 in RB cells were investigated via bioinformatics analysis, luciferase reporter assays, and RT‑qPCR and western blot analyses. It was revealed that the levels of miR‑330 expression were significantly downregulated in RB tissues and cell lines compared with in control healthy tissues and cells, respectively. Overexpression of miR‑330 in RB cells significantly reduced the viability and invasion of cells in vitro. Additionally, ρ‑associated coiled‑coil containing protein kinase 1 (ROCK1) was identified as a putative target of miR‑330 using bioinformatics analysis. Subsequent experiments revealed that miR‑330 interacted with the 3'‑untranslated region of ROCK1 and downregulated its expression in RB cells. Furthermore, the expression levels of ROCK1 were increased in RB tissues compared with healthy controls and negatively correlated with miR‑330 expression. Finally, upregulation of ROCK1 expression reversed the miR‑330‑induced inhibition of the viability and invasion of RB cells. Collectively, these results suggested that miR‑330 exhibits tumor‑suppressor activity in the development of RB by directly targeting ROCK1, indicating that restoration of miR‑330 expression may be a promising therapeutic technique in the treatment of patients with RB.

MicroRNA‑198 suppresses prostate tumorigenesis by targeting MIB1

MicroRNAs are small non-coding RNA molecules which act as modulators of gene function, and have been identified as playing important roles in cancer as both tumor suppressors and oncogenes. The present study aimed to examine the role of miR-198 in prostate cancer aggression by analyzing how it influences several hallmarks of cancer. Abundance of miR-198 in prostate cancer and association with clinical characteristics was analyzed using a CPC-Gene prostate cancer dataset. Overexpression of miR-198 was performed using transient transfection of miR-198 mimic prior to assaying proliferation, cell cycle, and colony formation in LNCaP and DU145 cell lines using standard protocols. In vivo tumor formation in athymic nude mice was examined using LNCaP xenografts with stable overexpression conferred using lentiviral miR-198 transduction. Protein and mRNA abundance of MIB1 was determined using western blotting and RT-qPCR respectively, while miR-198 binding to MIB1 was validated using a luciferase reporter assay. miR-198 abundance was lower in high Gleason grade prostate cancer relative to intermediate and low-grade cancer. Overexpression of miR-198 diminished proliferation of prostate cancer cell lines, increased G0/G1 cell cycle arrest, and significantly impaired colony formation. Elevated miR-198 abundance was also demonstrated to impair tumor formation in vivo using LNCaP xenografts. Mindbomb E3 ubiquitin protein ligase 1 (MIB1) was demonstrated to be directly targeted by miR-198, and knockdown of MIB1 recapitulated the effects of miR-198 on proliferation and colony formation. The present evidence supports miR-198 as an important tumor suppressor in prostate cancer, and demonstrates for the first time that it acts by targeting MIB1. The present study reinforces the importance and complexity of miRNA in regulating prostate cancer aggression.

Clinical value of microRNA-198-5p downregulation in lung adenocarcinoma and its potential pathways

Lung adenocarcinoma (LUAD), the main subtype of non-small cell lung cancer, is known to be regulated by various microRNAs (miRs/miRNAs); however, the role of miR-198-5p in LUAD has not been clarified. In the present study, the clinical value of miR-198-5p in LUAD and its potential molecular mechanism was evaluated. miR-198-5p expression was examined by reverse transcription-quantitative PCR (RT-qPCR) in 101 paired LUAD and adjacent normal lung tissues. Subsequently, the miR-198-5p expression level was determined from microarray data from the Gene Expression Omnibus, ArrayExpress and by meta-analyses. Furthermore, the target mRNAs of miR-198-5p from 12 miRNA-mRNA predictive tools were intersected with The Cancer Genome Atlas (TCGA)-based differentially expressed genes. In addition, Gene Ontology annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were conducted to determine the possible mechanism of miR-198-5p in LUAD. The Search Tool for the Retrieval of Interacting Genes/Proteins database was employed to construct a protein-protein interaction network among the potential target genes of miR-198-5p. The results showed that miR-198-5p expression was lower in LUAD tissues than in adjacent non-cancerous lung tissues (4.469±2.495 vs. 5.301±2.502; P=0.015). Meta-analyses, including the data from the present study and online microarray data, also verified the downregulation of miR-198-5p in 584 cases of LUAD. The expression of miR-198-5p was associated with the age, blood vessel invasion, Tumor-Node-Metastasis stage, and lymph node metastasis of patients with LUAD and served as an independent prognostic factor for survival. The hub genes of miR-198-5p were upregulated in LUAD, according to TCGA and The Human Protein Atlas. For the KEGG pathway analysis, the most enriched KEGG pathway was the p53 signaling pathway (P=1.42×10⁻⁶). These findings indicated that the downregulation of miR-198-5p may play a pivotal role in the development of LUAD by targeting various signaling pathways.

Insights into the roles of miRNAs; miR-193 as one of small molecular silencer in osteosarcoma therapy

Today, cancer is one of the most common causes of death. Osteosarcoma (OS) is a tumor in long bones and its prevalence is high in teenagers and young people. Among the methods that used to treat cancer, one can name chemotherapy, surgery, and radiotherapy. Since these methods have some disadvantages and they are not absolutely successful, the use of microRNAs (miRNAs) is very useful in diagnosis and treatment of OS. MiRNAs are small non-coding RNA molecules, containing 18-25 nucleotides, which are involved in the regulation of gene expression via binding to messenger RNA (mRNA). These RNAs are divided into two classes of suppressors and oncogenes. During OS, there is aberrant expression of several miRNAs. Among these miRNAs are downregulation of miR-193 that has been associated with cancer occurrence. The aim of the current manuscript is to have overview on the treatment approaches of OS with special focus on miR-193.

Loss of miR-198 and -206 during primary tumor progression enables metastatic dissemination in human osteosarcoma

The metastatic dissemination is a complex multistep process by which tumor cells from a primary site enter into the systemic circulation to finally spread at distant sites. Even if this mechanism is rare at the tumor level, it remains the major cause of Osteosarcoma-patients’ relapse and mortality. MicroRNAs (miRNAs) have recently been described as novel epigenetics’ genes’ expression regulators actively implicated in cancer progression and dissemination. The understanding of their implication in the metastatic spreading could help clinicians to improve the outcome of osteosarcoma. We established the miRNA’s expression-profile between primary bone-tumors (PTs), circulating tumor cells (CTCs) and lung metastatic (META) samples from in vivo mice xenograft models. Our results show that the expression level of the miR-198 and -206 was decreased in META samples, in which the expression of the metastasis-related receptor C-Met was up-regulated. Those expression variations were validated in osteosarcoma patient biopsies from matching primary tumors and lung metastasis. We validated in vitro the endogenous miRNAs inhibitory effects on both migration and invasion, as well as we confirmed by luciferase assays that the C-Met receptor is one of their bona-fide targets. The anti-metastatic effect of these miRNAs was also validated in vivo, as their direct injections into the tumors reduce the number of lung-metastases and prolongs the overall survival of the treated animals. All together, our results suggest the absence of the miR-198 and -206 as powerful predictive biomarkers of the tumor cell dissemination and the rationale of their potential therapeutic use in the treatment of Osteosarcoma.

Genetic testing for high-grade osteosarcoma: a guide for future tailored treatments?

INTRODUCTION

Genetic characterization of osteosarcoma has evolved during the last decade, thanks to the integrated application of conventional and new candidate-driven and genome-wide technologies. Areas covered: This review provides an overview of the state of art in genetic testing applied to osteosarcoma, with particular regard to novel candidate genetic biomarkers that can be analyzed in tumor tissue and blood samples, which might be used to predict toxicity and prognosis, detect disease relapse, and improve patients' selection criteria for tailoring treatment. Expert commentary: Genetic testing based on modern technologies is expected to indicate new osteosarcoma-related prognostic markers and driver genes, which may highlight novel therapeutic targets and patients stratification biomarkers. The definition of tailored or targeted treatment approaches may improve outcome of patients with localized tumors and, even more, of those with metastatic disease, for whom progress in cure probability is highly warranted.

Bortezomib inhibited the progression of diffuse large B-cell lymphoma via targeting miR-198

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin lymphoma, which is an aggressive malignancy with high variance of clinical features and response to the treatment. The proteasome inhibitor bortezomib (BTZ) has been demonstrated to suppress the progression of DLBCL, however, the underlying molecular mechanisms by which BTZ regulates the growth of DLBCL cells remain largely unknown. Increasing evidence has suggested that microRNAs (miRNAs) are novel targets of anti-cancer drugs to modulate the progression of cancers. Here, we showed BTZ treatment significantly inhibited the proliferation of DLBCL CRL-2630 cells. Mechanistically, exposure of BTZ up-regulated the expression of miR-198 in DLBCL cells. Depletion of miR-198 significantly reversed the inhibitory effect of BTZ on the proliferation of CRL-2630 cells. To further characterize the involvement of miR-198 in BTZ-induced growth defects of CRL-2630 cells, the downstream targets of miR-198 were predicted with the bioinformatics tools. The results showed that miR-198 bound the 3'-untranslated region (UTR) of the high mobility group AT-hook 1 (HMGA1) and suppressed the expression of HMGA1 in DLBCL cells. Consistently, BTZ treatment decreased the level of HMAG1 and inhibited the migration of DLBCL cells. Our results provided the possible mechanism by which BTZ suppressed the growth of DLBCL cells.

MiR-214 is an important regulator of the musculoskeletal metabolism and disease

MiR-214 belongs to a family of microRNA (small, highly conserved noncoding RNA molecules) precursors that play a pivotal role in biological functions, such as cellular function, tissue development, tissue homeostasis, and pathogenesis of diseases. Recently, miR-214 emerged as a critical regulator of musculoskeletal metabolism. Specifically, miR-214 can mediate skeletal muscle myogenesis and vascular smooth muscle cell proliferation, migration, and differentiation. MiR-214 also modulates osteoblast function by targeting specific molecular pathways and the expression of various osteoblast-related genes; promotes osteoclast activity by targeting phosphatase and tensin homolog (Pten); and mediates osteoclast-osteoblast intercellular crosstalk via an exosomal miRNA paracrine mechanism. Importantly, dysregulation in miR-214 expression is associated with pathological bone conditions such as osteoporosis, osteosarcoma, multiple myeloma, and osteolytic bone metastasis of breast cancer. This review discusses the cellular targets of miR-214 in bone, the molecular mechanisms governing the activities of miR-214 in the musculoskeletal system, and the putative role of miR-214 in skeletal diseases. Understanding the biology of miR-214 could potentially lead to the development of miR-214 as a possible biomarker and a therapeutic target for musculoskeletal diseases.

MicroRNA-2682-3p inhibits osteosarcoma cell proliferation by targeting CCND2, MMP8 and Myd88

Osteosarcoma is the most common primary bone malignancy in children and young adults. It is associated with dysregulation of certain microRNAs (miRNAs/miRs), which provides a target for osteosarcoma therapy. miR-2682-3p expression in osteosarcoma cell lines and tissues was assayed by reverse transcription-quantitative polymerase chain reaction and was upregulated or downregulated by transfection with miRNA mimics or inhibitors. miR-2682-3p was downregulated in osteosarcoma tissues and cell lines, and overexpression of miR-2682-3p inhibited tumor growth. Further studies revealed that cyclin D1 (CCND)2, matrix metalloproteinase (MMP)8, and myeloid differentiation primary response (Myd)88 were the direct targets of miR-2682-3p in osteosarcoma cells. Overexpression of miR-2682-3p promoted osteosarcoma cell apoptosis by targeting CCND2, MMP8, and Myd88, and vice-versa. Therefore, miR-2682-3p may act as a tumor suppressor gene, the downregulation of which contributed to the progression and metastasis of osteosarcoma, to provide a potential therapy target for patients with osteosarcoma.

miR-202-5p inhibits the migration and invasion of osteosarcoma cells by targeting ROCK1

Many studies have shown that microRNA regulates the development and treatment of osteosarcoma (OS). In many human cancer studies, the expression of microRNA-202 has been shown to be abnormal. The aim of the study was to examine the role of miR-202-5p in the occurrence and formation of OS. miR-202-5p and Rho-associated coiled-coil containing protein kinase 1 (ROCK1) levels were assessed using RT-qPCR in OS tissues and cell lines. The cell migrating and invasive abilities were detected by the Transwell assay in OS. Moreover, the relationship between miR-202-5p and ROCK1 was verified via luciferase reporter assay. The protein level of ROCK1 was identified by western blot analysis. Downregulation of miR-202-5p was identified in OS tissues and cell lines. In addition, the miR-202-5p overexpression had inhibitory action for cell migration and invasion in OS. Moreover, miR-202-5p directly targeted ROCK1 and negatively regulated its expression. Upregulation of ROCK1 had a carcinogenic effect in OS. Furthermore, the upregulation of ROCK1 restored the suppressive effect of miR-202-5p. miR-202-5p, in turn, weakened the abilities of cell migration and invasion in OS by inhibiting ROCK1 expression. As a result, miR-202-5p may be developed as a potential pathway in the reatment of OS.

Downregulation of microRNA‑198 suppresses cell proliferation and invasion in retinoblastoma by directly targeting PTEN

A number of studies have highlighted that aberrantly expressed microRNAs (miRNAs/miRs) serve crucial roles in the tumorigenesis and tumor development of retinoblastoma (RB). Hence, a full investigation of the biological roles and regulatory mechanisms of miRNAs in RB may provide novel therapeutic targets for patients with this malignancy. miR‑198 is frequently abnormally expressed in various types of human cancers. However, the expression level, biological roles and underlying mechanisms of miR‑198 in RB remain to be elucidated. In the present study, miR‑198 expression was upregulated in RB tissues and cell lines. Silencing of miR‑198 attenuated cell proliferation and invasion in RB. In addition, phosphatase and tensin homolog deleted on chromosome ten (PTEN) was predicted as a potential target of miR‑198 using bioinformatics analysis. Subsequent luciferase reporter assay indicated that the 3'‑untranslated region of PTEN can be directly targeted by miR‑198. Furthermore, miR‑198 inhibition increased the PTEN expression at the mRNA and protein levels in RB cells. In addition, PTEN mRNA expression was downregulated in RB tissues, and this downregulation was inversely associated with the expression level of miR‑198. PTEN knockdown rescued the inhibitory effects of miR‑198 underexpression on cell proliferation and invasion in RB. Notably, the downregulation of miR‑198 inactivated the phosphoinositide 3‑kinase (PI3K)/protein kinase B (AKT) signaling pathway in RB. These results demonstrated that miR‑198 may serve oncogenic roles in RB by directly targeting PTEN and regulating the PI3K/AKT signaling pathway. Hence, miR‑198 may be a promising therapeutic target for patients with RB.

MicroRNA-411 promoted the osteosarcoma progression by suppressing MTSS1 expression

MicroRNAs (miRNAs) play crucial roles in the progression of different tumors. In our study, we investigated the expression and roles of miR-411 in human osteosarcoma. In this study, we first confirmed that the miR-411 expression was higher in the serum of patients with osteosarcoma than in the serum of healthy volunteers. In addition, we found that the miR-411 expression was upregulated in the osteosarcoma tissues compared to that in the matched normal bone tissues. We also demonstrated that the miR-411 expression was upregulated in the four osteosarcoma cell lines. Elevated expression of miR-411 promoted osteosarcoma cell proliferation and migration. Moreover, we identified that metastasis suppressor protein 1 (MTSS1) was a direct target gene of miR-411 in the osteosarcoma cell. We also demonstrated that the MTSS1 expression was downregulated in the osteosarcoma tissues compared to that in the matched normal bone tissues. In addition, MTSS1 expression level was inversely correlated with miR-411 expression in the osteosarcoma tissues. Furthermore, elevated expression of miR-411 enhanced the osteosarcoma cell proliferation and migration through inhibiting the MTSS1 expression. These data suggested that miR-411 played as oncogene in the osteosarcoma partly by inhibiting the MTSS1 expression.

Clinical value of miR-198-5p in lung squamous cell carcinoma assessed using microarray and RT-qPCR

Background

To examine the clinical value of miR-198-5p in lung squamous cell carcinoma (LUSC).

Methods

Gene Expression Omnibus (GEO) microarray datasets were used to explore the miR-198-5p expression and its diagnostic value in LUSC. Real-time reverse transcription quantitative polymerase chain reaction was used to evaluate the expression of miR-198-5p in 23 formalin-fixed, paraffin-embedded (FFPE) LUSC tissues and corresponding non-cancerous tissues. The correlation between miR-198-5p expression and clinic pathological features was assessed. Meanwhile, putative target messenger RNAs of miR-198-5p were identified based on the analysis of differentially expressed genes in the Cancer Genome Atlas (TCGA) and 12 miRNA prediction tools. Subsequently, the putative target genes were sent to Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses.

Results

MiR-198-5p was low expressed in LUSC tissues. The combined standard mean difference (SMD) values of miR-198-5p expression based on GEO datasets were − 0.30 (95% confidence interval (CI) − 0.54, − 0.06) and − 0.39 (95% CI − 0.83, 0.05) using fixed effect model and random effect model, respectively. The sensitivity and specificity were not sufficiently high, as the area under the curve (AUC) was 0.7749 (Q* = 0.7143) based on summarized receiver operating characteristic (SROC) curves constructed using GEO datasets. Based on the in-house RT-qPCR, miR-198-5p expression was 4.3826 ± 1.7660 in LUSC tissues and 4.4522 ± 1.8263 in adjacent normal tissues (P = 0.885). The expression of miR-198-5p was significantly higher in patients with early TNM stages (I-II) than that in cases with advanced TNM stages (III-IV) (5.4400 ± 1.5277 vs 3.5690 ± 1.5228, P = 0.008). Continuous variable-based meta-analysis of GEO and PCR data displayed the SMD values of − 0.26 (95% CI − 0.48, − 0.04) and − 0.34 (95% CI − 0.71, 0.04) based on fixed and random effect models, respectively. As for the diagnostic value of miR-198-5p, the AUC based on the SROC curve using GEO and PCR data was 0.7351 (Q* = 0.6812). In total, 542 genes were identified as the targets of miR-198-5p. The most enriched Gene Ontology terms were epidermis development among biological processes, cell junction among cellular components, and protein dimerization activity among molecule functions. The pathway of non-small cell lung cancer was the most significant pathway identified using Kyoto Encyclopedia of Genes and Genomes analysis.

Conclusion

The expression of miR-198-5p is related to the TNM stage. Thus, miR-198-5p might play an important role via its target genes in LUSC.

Down-regulation of RPS9 Inhibits Osteosarcoma Cell Growth through Inactivation of MAPK Signaling Pathway

Objectives: Osteosarcoma is the most common malignant bone tumor in adolescents; however, the mechanisms involved in the pathogenesis and progression of osteosarcoma remain to be elucidated. Researchers have provided valuable insights into the tumorigenesis of Ribosomal protein S9 (RPS9) in some cancers. The purpose of this study was to elucidate the expression, functions, and mechanisms of RPS9 in human osteosarcoma. Methods: The expression of RPS9 in osteosarcoma tissues and cell lines was evaluated by qRT-PCR and western blotting. Knockdown of RPS9 induced by RNA interference (RNAi) method in three osteosarcoma cell lines (MNNG/HOS, MG63, and U2OS) was employed to analyze the effects of RPS9 on cell proliferation and cell cycle distribution. The host signaling pathways affected by RPS9 were detected using the intracellular signaling antibody array kit PathScan^®. Results: The expression of RPS9 was found to be up-regulated in human osteosarcoma tissues and cell lines. Its expression was positively correlated with Enneking stage and the tumor recurrence. Down-regulation of RPS9 inhibited osteosarcoma cell proliferation, colony-forming ability, and cell cycle G1 phase in vitro. In addition, our data demonstrated that knockdown of RPS9 repressed the protein levels of phospho-SAPK/JNK and phospho-p38. Conclusion: RPS9 is up-regulated and has a pro-tumor effect in osteosarcoma through the activation of MAPK signaling pathway and thus can be used as a potential target for gene therapy.

miR-198-induced upregulation of Livin may be associated with the prognosis and contribute to the oncogenesis of lung adenocarcinoma

Livin, a member of the inhibitor of apoptosis protein (IAP) family, is expressed at a high level in lung adenocarcinoma and influences the progression of cancer, and its response to chemotherapy and radiotherapy. Aberrant microRNA (miRNA) expression has also been associated with cancer initiation and development. However, the clinical significance of Livin and its relationship with miRNAs in lung adenocarcinoma are still unclear. In the present study, the expression level of Livin in 90 pairs of lung adenocarcinoma and their adjacent tissues were detected by immunohistochemistry staining. Spearman correlation and Kaplan-Meier, univariate and multivariate analyses were applied to evaluate the correlation between the expression of Livin and clinical characteristics. With the integration of bioinformatics analysis and dual-luciferase reporter gene assays, we identified the miRNA that can target Livin mRNA. The functional effects of miRNA-mediated Livin knockdown were assessed by Cell Counting Kit-8 (CCK-8) and apoptosis assays, and cell cycle analysis. The present study revealed that Livin was upregulated in lung adenocarcinoma tissues and may be associated with the poor prognosis in lung adenocarcinoma patients. The overexpression of Livin is partly caused by the downregulation of miR-198. Further exploration revealed that miRNA-198-mediated silencing of Livin significantly inhibited cell growth and enhanced apoptosis of A549 cells, accompanied by marked upregulation of caspase-3. Finally, we observed that the miR-198 overexpression and Livin neutralization had similar effects on improving cisplatin chemosensitivity in A549 cells. Overall, these findings suggest that Livin has the potential to become a biomarker for predicting the prognosis of lung adenocarcinoma and may provide a promising strategy for assisting chemotherapy of lung adenocarcinoma through the miR-198/Livin/caspase-3 regulatory network.

MicroRNA-195 inhibits the behavior of cervical cancer tumors by directly targeting HDGF

MicroRNAs (miRNAs/miRs) are a class of conserved non-coding endogenous small regulatory RNAs that regulate target gene expression by binding to the 3'-untranslated region of target mRNAs in a base-pairing manner, resulting in repression of transcription or degradation of target mRNAs. It has been demonstrated previously that the abnormal expression of miRNAs is involved in the carcinogenesis and progression of cervical cancer. The aim of the present study was to investigate the expression, biological functions and underlying molecular mechanisms of miR-195 in cervical cancer. The reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression level of miR-195 in cervical cancer tissues and cell lines. Following transfection, an MTT assay, cell migration and invasion assays, western blot analysis and a dual-luciferase reporter assay were performed in human cervical cancer cells. In the present study, it was identified that miR-195 was downregulated in cervical cancer tissues and cell lines. Additionally, upregulation of miR-195 and knockdown of hepatoma-derived growth factor (HDGF) inhibited proliferation, migration and invasion of cervical cancer cells. Furthermore, a dual-luciferase reporter assay identified that HDGF was a direct target gene of miR-195. RT-qPCR and western blot analysis demonstrated that miR-195 mimic inhibited HDGF expression at the mRNA and protein levels, whereas miR-195 inhibitor enhanced HDGF expression at the mRNA and protein levels. These results indicated that miR-195 targeted HDGF to inhibit the behavior of tumors in cervical cancer. These results also suggested that miR-195 was a potential therapeutic biomarker of cervical cancer.

miR-1297 regulates neural stem cell differentiation and viability through controlling Hes1 expression

OBJECTIVES

Neural stem cells (NSCs) are self-renewing, undifferentiated and multipotent precursors that can generate neuronal and glial lineages. MicroRNAs (miRNAs) are small non-coding RNAs that act crucial roles in cell proliferation, differentiation and migration. However, the role of miR-1297 in the development of NSCs is still unknown.

MATERIALS AND METHODS

Primary NSCs were isolated from rat's embryos. The expression of miR-1297 and Hes1 were measured by qRT-PCR. Western blot was performed to detect the protein expression of Hes1, β-tubulin-III and GFAP.

RESULTS

We showed that miR-1297 expression was upregulated during NSC differentiation, while the expression of Hes1 was decreased during NSC differentiation. Elevated expression of miR-1297 promoted the NSCs viability and increased the formation of NSCs to neurospheres. Ecoptic expression of miR-1297 promoted β-tubulin-III expression in the NSCs. Overexpression of miR-1297 decreased GFAP expression in the NSCs. Furthermore, we demonstrated that miR-1297 regulated NSCs viability and differentiation by directly targeting Hes1. Overexpression of miR-1297 suppressed Hes1 expression in the NSCs.

CONCLUSIONS

These results suggested that miR-1297 played an important role in NSCs viability and differentiation through inhibiting Hes1 expression.

What Is New in the miRNA World Regarding Osteosarcoma and Chondrosarcoma?

Despite the availability of multimodal and aggressive therapies, currently patients with skeletal sarcomas, including osteosarcoma and chondrosarcoma, often have a poor prognosis. In recent decades, advances in sequencing technology have revealed the presence of RNAs without coding potential known as non-coding RNAs (ncRNAs), which provides evidence that protein-coding genes account for only a small percentage of the entire genome. This has suggested the influence of ncRNAs during development, apoptosis and cell proliferation. The discovery of microRNAs (miRNAs) in 1993 underscored the importance of these molecules in pathological diseases such as cancer. Increasing interest in this field has allowed researchers to study the role of miRNAs in cancer progression. Regarding skeletal sarcomas, the research surrounding which miRNAs are involved in the tumourigenesis of osteosarcoma and chondrosarcoma has rapidly gained traction, including the identification of which miRNAs act as tumour suppressors and which act as oncogenes. In this review, we will summarize what is new regarding the roles of miRNAs in chondrosarcoma as well as the latest discoveries of identified miRNAs in osteosarcoma.

Elevated expression of microRNA-19a predicts a poor prognosis in patients with osteosarcoma

MicroRNA (miR)-19a, a member of the miR-17-92 cluster, functions as an oncomiRNA in multiple kinds of cancers. However, its involvement in human osteosarcomas remains unclear. In this study, to analyze the expression pattern of miR-19a and to investigate its clinical implication in human osteosarcomas, quantitative reverse-transcription polymerase chain reaction was performed to detect expression levels of miR-19a in 166 self-pairs of osteosarcoma and noncancerous bone tissues. Associations between miR-19a expression and various clinicopathological parameters and patients' prognosis of osteosarcomas were further evaluated. As a results, miR-19a expression in osteosarcoma tissues was significantly higher than that in corresponding noncancerous bone tissues (P<0.001). Osteosarcoma patients with high miR-19a expression more frequently had large tumor size (P=0.03), advanced clinical stage (P=0.01), positive distant metastasis (P=0.008) and poor response to chemotherapy (P=0.01) than those with low miR-19a expression. Additionally, kaplan-Meier analysis showed that both overall and disease-free survivals of osteosarcoma patients with high miR-19a expression were shorter than those with low miR-19a expression (both P<0.001). Further multivariate analysis identified miR-19a expression as an independent prognostic factor for both overall (P=0.001) and disease-free (P=0.006) survivals. In conclusion, the aberrant expression of miR-19a may play a crucial role in development and progression of human osteosarcomas. MiR-19a may act as a novel prognostic marker for patients with this malignancy.

MicroRNA-124 upregulation inhibits proliferation and invasion of osteosarcoma cells by targeting sphingosine kinase 1

Increasing evidence has confirmed that the dysregulation of microRNAs (miRNAs) contributes to the proliferation and invasion of human cancers. Previous studies have shown that the dysregulation of miR-124 is in numerous cancers. However, the roles of miR-124 in human osteosarcoma (OS) have not been well clarified. Therefore, this study was to investigate the biological functions and molecular mechanisms of miR-124 in OS cell lines, discussing whether it could be a therapeutic biomarker of OS in the future. In this study, our results demonstrated that miR-124 was down-regulated in OS cell lines and tissues. Furthermore, the low level of miR-124 was associated with increased expression of Sphingosine kinase 1 (SPHK1) in OS cells and tissues. Up-regulation of miR-124 significantly inhibited cell proliferation, invasion, and MMP-2 and -9 expressions of OS cells. Bioinformatics analysis predicted that the SPHK1 was a potential target of miR-124. Further study by luciferase reporter assay demonstrated that miR-124 could directly target SPHK1. Overexpression of SPHK1 in OS cells transfected with miR-124 mimic partially reversed the inhibitory of miR-124. In conclusion, miR-124 inhibited cell proliferation and invasion in OS cells by downregulation of SPHK1, and that downregulation of SPHK1 was essential for the miR-124-inhibited cell invasion and in OS cells.