Serum miR-195 is a diagnostic and prognostic marker for osteosarcoma

A comprehensive overview of liquid biopsy applications in pediatric solid tumors

Liquid biopsies are emerging as an alternative source for pediatric cancer biomarkers with potential applications during all stages of patient care, from diagnosis to long-term follow-up. While developments within this field are reported, these mainly focus on dedicated items such as a specific liquid biopsy matrix, analyte, and/or single tumor type. To the best of our knowledge, a comprehensive overview is lacking. Here, we review the current state of liquid biopsy research for the most common non-central nervous system pediatric solid tumors. These include neuroblastoma, renal tumors, germ cell tumors, osteosarcoma, Ewing sarcoma, rhabdomyosarcoma and other soft tissue sarcomas, and liver tumors. Within this selection, we discuss the most important or recent studies involving liquid biopsy-based biomarkers, anticipated clinical applications, and the current challenges for success. Furthermore, we provide an overview of liquid biopsy-based biomarker publication output for each tumor type based on a comprehensive literature search between 1989 and 2023. Per study identified, we list the relevant liquid biopsy-based biomarkers, matrices (e.g., peripheral blood, bone marrow, or cerebrospinal fluid), analytes (e.g., circulating cell-free and tumor DNA, microRNAs, and circulating tumor cells), methods (e.g., digital droplet PCR and next-generation sequencing), the involved pediatric patient cohort, and proposed applications. As such, we identified 344 unique publications. Taken together, while the liquid biopsy field in pediatric oncology is still behind adult oncology, potentially relevant publications have increased over the last decade. Importantly, steps towards clinical implementation are rapidly gaining ground, notably through validation of liquid biopsy-based biomarkers in pediatric clinical trials.

Biopsy Techniques for Musculoskeletal Tumors: Basic Principles and Specialized Techniques

Biopsy is a pivotal component in the diagnostic process of bone and soft tissue tumors. The objective is to obtain adequate tissue without compromising local tumor dissemination and the patient's survival. This review explores contemporary principles and practices in musculoskeletal biopsies, emphasizing the critical role of diagnostic accuracy while also delving into the evolving landscape of liquid biopsies as a promising alternative in the field. A thorough literature search was done in PubMed and Google Scholar as well as in physical books in libraries to summarize the available biopsy techniques for musculoskeletal tumors, discuss the available methods, risk factors, and complications, and to emphasize the challenges related to biopsies in oncology. Research articles that studied the basic principles and specialized techniques of biopsy techniques in tumor patients were deemed eligible. Their advantages and disadvantages, technical and pathophysiological mechanisms, and possible risks and complications were reviewed, summarized, and discussed. An inadequately executed biopsy may hinder diagnosis and subsequently impact treatment outcomes. All lesions should be approached with a presumption of malignancy until proven otherwise. Liquid biopsies have emerged as a potent non-invasive tool for analyzing tumor phenotype, progression, and drug resistance and guiding treatment decisions in bone sarcomas and metastases. Despite advancements, several barriers remain in biopsies, including challenges related to costs, scalability, reproducibility, and isolation methods. It is paramount that orthopedic oncologists work together with radiologists and pathologists to enhance diagnosis, patient outcomes, and healthcare costs.

Novel pyroptosis-related lncRNAs and ceRNAs predict osteosarcoma prognosis and indicate immune microenvironment signatures

Objective

To study pyroptosis-related biomarkers that are associated with the prognosis and immune microenvironment characteristics of osteosarcoma (OS). The goal is to establish a foundation for the prognosis and treatment of OS.

Methods

We retrieved transcriptome and clinical data from The Cancer Genome Atlas (TCGA) database for 88 OS patients. Using this data, we constructed a prognostic model to identify pyroptosis-related genes (PRGs) associated with OS prognosis. To further explore the biological function of these PRGs, we performed enrichment analysis. To identify pyroptosis-related long non-coding RNAs (PRLncs) associated with the prognosis of OS, we performed co-expression analysis. Subsequently, a risk prognostic model was constructed using these PRLncs to generate a risk score, termed as PRLncs-score, thereby obtaining PRLncs associated with the prognosis of OS. The accuracy of the prognostic model was verified through survival analysis, risk curve, independent prognostic analysis, receiver operating characteristic (ROC) curve, difference analysis between high- and low-risk groups, and clinical correlation analysis. And to determine whether PRLncs-score is independent prognostic factor for OS. In addition, we further conducted external and internal validation for the risk prognosis model. Further analyses of immune cell infiltration and tumor microenvironment were performed. A pyroptosis-related competitive endogenous RNA (PRceRNA) network was constructed to obtain PRceRNAs associated with the prognosis of OS and performed gene set enrichment analysis (GSEA) on PRceRNA genes.

Results

We obtained five PRGs (CHMP4C, BAK1, GSDMA, CASP1, and CASP6) that predicted OS prognosis and seven PRLncs (AC090559.1, AP003119.2, CARD8-AS1, AL390728.4, SATB2-AS1, AL133215.2, and AC009495.3) and one PRceRNA (CARD8-AS1-hsa-miR-21-5p-IL1B) that predicted OS prognosis and indicated characteristics of the OS immune microenvironment. The PRLncs-score, in combination with other clinical features, was established as an independent prognostic factor for OS patients. Subsequent scrutiny of the tumor microenvironment and immune infiltration indicated that patients with low-PRLncs-scores were associated with reduced metastatic risk, improved survival rates, heightened levels of immune cells and stroma, and increased immune activity compared to those with high-PRLncs-scores.

Conclusion

The study's findings offer insight into the prognosis of OS and its immune microenvironment, and hold promise for improving early diagnosis and immunotherapy.

A spotlight on the interplay of signaling pathways and the role of miRNAs in osteosarcoma pathogenesis and therapeutic resistance

Osteosarcoma (OS) is one of the most common bone cancers that constantly affects children, teenagers, and young adults. Numerous epigenetic elements, such as miRNAs, have been shown to influence OS features like progression, initiation, angiogenesis, and treatment resistance. The expression of numerous genes implicated in OS pathogenesis might be regulated by miRNAs. This effect is ascribed to miRNAs' roles in the invasion, angiogenesis, metastasis, proliferation, cell cycle, and apoptosis. Important OS-related mechanistic networks like the WNT/b-catenin signaling, PTEN/AKT/mTOR axis, and KRAS mutations are also affected by miRNAs. In addition to pathophysiology, miRNAs may influence how the OS reacts to therapies like radiotherapy and chemotherapy. With a focus on how miRNAs affect OS signaling pathways, this review seeks to show how miRNAs and OS are related.

Oncogenic Dysregulation of Circulating Noncoding RNAs: Novel Challenges and Opportunities in Sarcoma Diagnosis and Treatment

Simple Summary

Body fluids contain different classes of RNA molecules such as protein-coding messenger RNAs (mRNA) and noncoding RNAs, including microRNAs (miRNAs), long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs). These circulating RNAs can travel naked or packed into extracellular vesicles and display valuable potential as non-invasive biomarkers of sarcoma malignancy. In this review, we summarize current knowledge on the possible functions of these circulating RNAs and discuss their possible exploitation as novel markers to improve sarcoma diagnosis and prognosis. Despite the recent advance in technological tools have improved protocols for the extraction and detection of circulating RNA, many aspects related to the biology of these molecules remain to be elucidated. In particular, the lack of standardization in the assessment of these markers makes difficult their adoption into clinical practice.

Abstract

Sarcomas comprise a heterogeneous group of rare mesenchymal malignancies. Sarcomas can be grouped into two categories characterized by different prognosis and treatment approaches: soft tissue sarcoma and primary bone sarcoma. In the last years, research on novel diagnostic, prognostic or predictive biomarkers in sarcoma management has been focused on circulating tumor-derived molecules as valuable tools. Liquid biopsies that measure various tumor components, including circulating cell-free DNA and RNA, circulating tumor cells, tumor extracellular vesicles and exosomes, are gaining attention as methods for molecular screening and early diagnosis. Compared with traditional tissue biopsies, liquid biopsies are minimally invasive and blood samples can be collected serially over time to monitor cancer progression. This review will focus on circulating noncoding RNA molecules from liquid biopsies that are dysregulated in sarcoma malignancies and discuss advantages and current limitations of their employment as biomarkers in the management of sarcomas. It will also explore their utility in the evaluation of the clinical response to treatments and of disease relapse. Moreover, it will explore state-of-the-art techniques that allow for the early detection of these circulating biomarkers. Despite the huge potential, current reports highlight poor sensitivity, specificity, and survival benefit of these methods, that are therefore still insufficient for routine screening purposes.

Long non-coding RNA DUXAP10 exerts oncogenic properties in osteosarcoma by recruiting HuR to enhance SOX18 mRNA stability

Recent studies have demonstrated that several long non-coding RNAs (lncRNAs) play an important role in the occurrence and development of osteosarcoma (OS). However, more lncRNAs and their mechanisms in regulating growth and migration of OS cells remain to be investigated. In this study, we identified an lncRNA called DUXAP10 by analysis of GEO data, which was significantly up-regulated in OS tissues and cell lines. Experiments in vitro revealed that lncRNA DUXAP10 promoted proliferation, migration, and invasion of OS cells and inhibited their apoptosis. We also demonstrated that DUXAP10 promoted the formation and growth of OS by tumor formation assay. Furthermore, SOX18 was identified as a critical downstream target of DUXAP10 by transcriptome RNA-seq. Mechanistically, DUXAP10 mainly localized in cytoplasm and could specifically bind to HuR to increase the stability of SOX18 mRNA. Meanwhile, SOX18 knockdown largely reversed increased proliferation of OS cells induced by DUXAP10 overexpression. Findings from this study indicate that lncRNA DUXAP10 can act as an oncogene in osteosarcoma by binding HuR to up-regulate the expression of SOX18 at a post-transcriptional level, which may provide a new target for OS clinical diagnosis and treatment.

hnRNP A1 and hnRNP C associate with miR-17 and miR-18 in thyroid cancer cells

Heterogeneous nuclear ribonucleoproteins (hnRNPs) are essential players in the regulation of gene expression. The majority of the twenty different hnRNP proteins act through the modulation of pre-mRNA splicing. Most have been shown to regulate the expression of critical genes for the progression of tumorigenic processes and were also observed to be overexpressed in several types of cancer. Moreover, these proteins were described as essential components for the maturation of some microRNAs (miRNAs). In the human genome, over 70% of miRNAs are transcribed from introns; therefore, we hypothesized that regulatory proteins involved with splicing could be important for their maturation. Increased expression of the miR-17-92 cluster has already been shown to be related to the development of many cancers, such as thyroid, lung, and lymphoma. In this article, we show that overexpression of hnRNP A1 and hnRNP C in BCPAP thyroid cancer cells directly affects the expression of miR-17-92 miRNAs. Both proteins associate with the 5'-end of this cluster, strongly precipitate miRNAs miR-17 and miR-18a and upregulate the expression of miR-92a. Upon overexpression of these hnRNPs, BCPAP cells also show increased proliferation, migration, and invasion rates, suggesting upregulation of these proteins and miRNAs is related to an enhanced tumorigenic phenotype.

Clinical Application of Artificial Intelligence: Auto-Discerning the Effectiveness of Lidocaine Concentration Levels in Osteosarcoma Femoral Tumor Segment Resection

Adolescents and children worldwide are threatened by osteosarcoma, a tumor that predominantly affects the long bone epiphysis. Osteosarcoma is the most common and highly malignant bone tumor in youngsters. Early tumor detection is the key to effective treatment of this disease. The discovery of biomarkers and the growing understanding of molecules and their complex interactions have improved the outcome of clinical trials in osteosarcoma. This article describes biomarkers of osteosarcoma with the aim of positively influencing the progress of clinical treatment of osteosarcoma. Femoral bone tumor is a typical condition of osteosarcoma. Due to the wide range of femoral stem types, complexities in the distal femur, and tumors in the rotor part of femur, physicians following the traditional clinical approach face difficulties in removing the lesion and fixing the femur with resection of the tumor segment. In this paper, the effect of small doses of different concentrations of lidocaine anesthesia in patients undergoing lumpectomy for osteosarcoma femoral tumor segments is investigated. A computer-based artificial intelligence method for automated determination of different concentration levels of lidocaine anesthesia and amputation of osteosarcoma femoral tumor segment is proposed. Statistical analysis is carried on the empirical data including intraoperative bleeding, intraoperative and postoperative pain scores, surgical operation time, postoperative complications, patient satisfaction, and local anesthetic dose. The results showed that the patients in the study group had low intraoperative bleeding, short operation time, low postoperative hematoma formation rate, high patient satisfaction, higher dosage of anesthetic solution, and low dosage of lidocaine. Results revealed that mean arterial pressure and heart rate in extubating and intubating were significantly lower in the observation group than in the control group, and a significant difference (P < 0.05) was observed between the two groups. This proves that the proposed algorithm can adequately reduce bleeding, alleviate postoperative pain, shorten operation time, reduce complications, accelerate recovery, and ensure better treatment results.

Cancer-Derived Extracellular Vesicles: Their Role in Sarcoma

Soft tissue sarcomas (STS) are rare malignancies with limited responses to anticancer therapy. Extracellular vesicles (EVs) are a heterogeneous group of bi-lipid layer sacs secreted by cells into extracellular space. Investigations of tumor-derived EVs have revealed their functional capabilities, including cell-to-cell communication and their impact on tumorigenesis, progression, and metastasis; however information on the roles of EVs in sarcoma is currently limited. In this review we investigate the role of various EV cargos in sarcoma and the mechanisms by which those cargos can affect the recipient cell phenotype and the aggressivity of the tumor itself. The study of EVs in sarcoma may help establish novel therapeutic approaches that target specific sarcoma subtypes or biologies, thereby improving sarcoma therapeutics in the future.

Research Progress of Exosome-Loaded miRNA in Osteosarcoma

Currently, although the improvement of surgical techniques and the development of chemotherapy drugs have brought a certain degree of development to the treatment of osteosarcoma, the treatment of osteosarcoma has many shortcomings, and its treatment is limited. MiRNAs and exosomes can be used as diagnostic tools, and they play an important role in the occurrence and chemotherapy resistance of osteosarcoma. Therefore, providing a new method for the treatment of osteosarcoma is the key to solving this problem. To systematically summarize the research status of exoskeleton drug-loaded miRNA in osteosarcoma, we identified and evaluated 208 studies and found that exosome-carrying miRNA can be used as an index for the diagnosis and prognosis of osteosarcoma and share a certain relationship with chemosensitivity. In addition, exosomes can also be used as a carrier of genetic drugs able to regulate the progression of osteosarcoma. Based on the above findings, we propose suggestions for the future development of this field, aiming to bring new ideas for the early diagnosis and treatment of osteosarcoma.

Osteosarcoma and Metastasis

Osteosarcoma is the most common primary bone malignancy in adolescents. Its high propensity to metastasize is the leading cause for treatment failure and poor prognosis. Although the research of osteosarcoma has greatly expanded in the past decades, the knowledge and new therapy strategies targeting metastatic progression remain sparse. The prognosis of patients with metastasis is still unsatisfactory. There is resonating urgency for a thorough and deeper understanding of molecular mechanisms underlying osteosarcoma to develop innovative therapies targeting metastasis. Toward the goal of elaborating the characteristics and biological behavior of metastatic osteosarcoma, it is essential to combine the diverse investigations that are performed at molecular, cellular, and animal levels from basic research to clinical translation spanning chemical, physical sciences, and biology. This review focuses on the metastatic process, regulatory networks involving key molecules and signaling pathways, the role of microenvironment, osteoclast, angiogenesis, metabolism, immunity, and noncoding RNAs in osteosarcoma metastasis. The aim of this review is to provide an overview of current research advances, with the hope to discovery druggable targets and promising therapy strategies for osteosarcoma metastasis and thus to overcome this clinical impasse.

MicroRNAs as prognostic biomarkers for survival outcome in osteosarcoma: A meta-analysis

BACKGROUND

Osteosarcoma was considered to be one of the most prevalent malignant bone tumors in adolescents.

AIM

To explore the prognostic significance of microRNA (miRNA) in osteosarcoma.

METHODS

The literature was selected by searching online in PubMed, Embase, Web of Science, Cochrane Library, China National Knowledge Infrastructure, and Wanfang Database until July 1, 2021. The pooled hazard ratio (HR) with corresponding 95% confidence interval (CI) for the outcomes of overall survival (OS), disease-free survival (DFS), progression-free survival (PFS) and recurrence-free survival were calculated. Subgroup analyses were carried out to identify potential sources of heterogeneity. Publication bias was assessed by Egger’s bias indicator test.

RESULTS

A total of 60 studies from 54 articles with 5824 osteosarcoma patients were included for this meta-analysis. The pooled HR for OS, DFS, PFS were 2.92 (95%CI: 2.43-3.41, P = 0.000), 3.70 (95%CI: 2.80-4.61, P = 0.000), and 3.57 (95%CI: 1.60-5.54, P = 0.000), respectively. The high miR-21 expression levels were related to poor OS in osteosarcoma (HR = 2.86, 95%CI: 1.20-4.53, P = 0.001). Subgroup analysis demonstrated that a high expression level of miRNA correlated with worse OS (HR: 3.56, 95%CI: 2.59-4.54, P = 0.000). In addition, miRNA from tissue (HR: 3.20, 95%CI: 2.16-4.23, P = 0.000) may be a stronger prognostic biomarker in comparison with that from serum and plasma.

CONCLUSION

miRNA (especially miR-21) could be served as a potential prognostic biomarker for osteosarcoma. A high expression level of miRNA in tumor tissue correlated with worse OS of osteosarcoma.

Circulating MicroRNAs as Novel Potential Diagnostic Biomarkers for Osteosarcoma: A Systematic Review

Osteosarcoma (OS) is a fast-progressing bone tumor with high incidence in children and adolescents. The main diagnostic methods for OS are imaging exams and biopsies. In spite of the several resources available for detecting the disease, establishing an early diagnosis is still difficult, resulting in worse prognosis and lower survival rates for patients with OS. The identification of novel biomarkers would be helpful, and recently, circulating microRNAs (miRNAs) have been pointed to as possible non-invasive biomarkers. In order to assess the effectiveness of miRNA research, we performed a systematic review to assess the potential role of circulating miRNAs as biomarkers for OS diagnosis. We performed a search in various databases—PubMed, LILACS (Literatura Latino-americana e do Caribe em Ciências da Saúde), VHL (Virtual Health Library), Elsevier, Web of Science, Gale Academic One File—using the terms: “Circulating microRNAs” OR “plasma microRNAs” OR “serum microRNAs” OR “blood microRNAs” OR “cell-free microRNAs” OR “exosome microRNAs” OR “extracellular vesicles microRNAs” OR “liquid biopsy” AND “osteosarcoma” AND “diagnostic”. We found 35 eligible studies that were independently identified and had had their quality assessed according to Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) guidelines. Despite the useful number of publications on this subject and the fact that several microRNAs showed excellent diagnostic performance for OS, the lack of consistency in results suggests that additional prospective studies are needed to confirm the role of circulating miRNAs as non-invasive biomarkers in OS.

Comprehensive serum and tissue microRNA profiling in dedifferentiated liposarcoma

Sarcoma is a rare cancer with several subtypes; therefore, our understanding of the pathogenesis of sarcoma is limited, and designing effective treatments is difficult. Circulating microRNAs (miRNAs), including exosomal miRNAs, have attracted attention as biomarkers in cancer. However, the roles of miRNAs and exosomes in sarcoma remain unclear. The present analysis of tissue and serum miRNA expression in osteosarcoma, Ewing's sarcoma and dedifferentiated liposarcoma (DDLPS) identified miR-1246, −4532, −4454, −619-5p and −6126 as biomarkers for DDLPS. These miRNAs were highly expressed in human DDLPS cell lines and exosomes, suggesting that they are secreted from DDLPS tissues. The present results suggested that specific miRNAs may be used as biomarkers for early diagnosis or treatment targets in DDLPS.

MicroRNA expression profile in serum reveals novel diagnostic biomarkers for endometrial cancer

Purpose: Circulating microRNAs (miRNAs) prove to be promising diagnostic biomarkers for various cancers, including endometrial cancer (EC). The present study aims to identify serum microRNAs that can serve as potential biomarkers for EC diagnosis.

Patients and methods: A total of 92 EC and 102 normal control (NC) serum samples were analyzed using quantitative real-time polymerase chain reaction (qRT-PCR) in this four-phase experiment. The logistic regression method was used to construct a diagnostic model based on the differentially expressed miRNAs in serum. The receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic value. To further validate the diagnostic capacity of the identified signature, the 6-miRNA marker was compared with previously reported biomarkers and verified in three public datasets. In addition, the expression characteristics of the identified miRNAs were further explored in tissue and serum exosomes samples.

Results: Six miRNAs (miR-143-3p, miR-195-5p, miR-20b-5p, miR-204-5p, miR-423-3p, and miR-484) were significantly overexpressed in the serum of EC compared with NCs. Areas under the ROC of the 6-miRNA signatures were 0.748, 0.833, and 0.967 for the training, testing, and the external validation phases, respectively. The identified signature has a very stable diagnostic performance in the large cohorts of three public datasets. Compared with previously identified miRNA biomarkers, the 6-miRNA signature in the present study has superior performance in diagnosing EC. Moreover, the expression of miR-143-3p and miR-195-5p in tissues and the expression of miR-20b-5p in serum exosomes were consistent with those in serum.

Conclusions: We established a 6-miRNA signature in serum and they could function as potential non-invasive biomarker for EC diagnosis.

miRNA identification by nuclease digestion in ELISA for diagnosis of osteosarcoma

Osteosarcoma is a bone cancer formed by the cells of the bone. Children, young adults, and teens are highly affected by osteosarcoma. Early identification of osteosarcoma is mandatory to improve the treatment and increase the lifespan of the patients. MicroRNA-195 (miR-195) was shown to be a suitable biomarker for osteosarcoma, and the present study describes a sensitive method of miR-195 identification by nuclease digestion in ELISA to detect and quantify the level of miR-195. S1 nuclease catalyzed endo- and exonucleolytic digestion of single-stranded (ss) RNA and DNA on ELISA polystyrene substrate, which helped to identify duplexed miR-195. This method selectively and specifically identified miR-195 without any biofouling interactions and reached the limit of detection at 10 fM within the range from 10 fM to 10 nM. Due to complete digestion of ssDNA, single- and triple-mismatched sequences failed to increase the ELISA signal, indicating specific miRNA detection. Furthermore, human serum spiked with miR-195 did not interfere with the detection, confirming selective identification. This method identified miR-195 at a lower level and will help to diagnose earlier stages of osteosarcoma.

Colorimetric identification of miRNA-195 sequence for diagnosing osteosarcoma

Improving biosensing performance is mandatory for biomolecular recognition and disease identification. Gold nanoparticle (GNP)-based colorimetric assay is the easy and cost-effective identification method by a naked eye detection. In this research, osteosarcoma biomarker (miRNA-195) was identified by citrate-capped GNP-colorimetric assay. As salt-induced aggregation was used to observe the color changes of GNP, sodium chloride (NaCl) and capture DNA were optimized as 50 mM and ∼20 pmol, respectively. The capture DNA only on GNP could not stabilize under high NaCl, and the color of GNP turned into purple. At the same time, when capture DNA was hybridized with target, the condition can stabilize the GNP under higher NaCl, which retains the GNP color as red. This simple assay reaches the limit of detection of target miRNA-195 as ∼40 fmol. Control experiments with noncomplementary DNA turned the solution into purple, indicating the specific detection of target. The mixture of target in diluted serum retains the color of the GNP solution to be red, indicating the selective detection of target DNA. This simple assay helps to quantify the level of miRNA-195 target DNA and to diagnose the osteosarcoma.

Osteosarcoma Pathogenesis Leads the Way to New Target Treatments

Osteosarcoma (OS) is a rare condition with very poor prognosis in a metastatic setting. Basic research has enabled a better understanding of OS pathogenesis and the discovery of new potential therapeutic targets. Phase I and II clinical trials are already ongoing, with some promising results for these patients. This article reviews OS pathogenesis and new potential therapeutic targets.

Role of microRNAs in the crosstalk between osteosarcoma cells and the tumour microenvironment

Osteosarcoma (OS) is the most common primary bone tumour, with a peak incidence in adolescents, and the five-year survival rate of patients with metastasis or recurrence is much lower than that of patients without metastasis and recurrence. OS is initiated and develops in a complex tumour microenvironment (TME) that contains many different components, such as osteoblasts, osteoclasts, mesenchymal stem cells, fibroblasts, immune cells, extracellular matrix (ECM), extracellular vesicles, and cytokines. The extensive interaction between OS and the TME underlies OS progression. Therefore, rather than targeting OS cells, targeting the key factors in the TME may yield novel therapeutic approaches. MicroRNAs (miRNAs) play multiple roles in the biological behaviours of OS, and recent studies have implied that miRNAs are involved in mediating the communication between OS cells and the surrounding TME. Here, we review the TME landscape and the miRNA dysregulation of OS, describe the role of the altered TME in OS development and highlight the role of miRNA in the crosstalk between OS cells and the TME.

MicroRNA-195 controls MICU1 expression and tumor growth in ovarian cancer

MICU1 is a mitochondrial inner membrane protein that inhibits mitochondrial calcium entry; elevated MICU1 expression is characteristic of many cancers, including ovarian cancer. MICU1 induces both glycolysis and chemoresistance and is associated with poor clinical outcomes. However, there are currently no available interventions to normalize aberrant MICU1 expression. Here, we demonstrate that microRNA-195-5p (miR-195) directly targets the 3' UTR of the MICU1 mRNA and represses MICU1 expression. Additionally, miR-195 is under-expressed in ovarian cancer cell lines, and restoring miR-195 expression reestablishes native MICU1 levels and the associated phenotypes. Stable expression of miR-195 in a human xenograft model of ovarian cancer significantly reduces tumor growth, increases tumor doubling times, and enhances overall survival. In conclusion, miR-195 controls MICU1 levels in ovarian cancer and could be exploited to normalize aberrant MICU1 expression, thus reversing both glycolysis and chemoresistance and consequently improving patient outcomes.

Serum-Derived microRNAs as Prognostic Biomarkers in Osteosarcoma: A Meta-Analysis

Recent reports suggest that microRNAs (miRNAs) may serve as prognostic biomarkers in osteosarcoma. Due to osteosarcoma's early metastasis and poor prognosis, it is very important to find novel prognostic biomarkers for improving osteosarcoma's prognosis. Herein we propose a meta-analysis for serum miRNA's prognostic value in osteosarcoma. In this study, the literature available from PubMed, Web of Science, Embase, and Cochrane Library databases was reviewed. The pooled hazard ratios (HRs) with their 95% confidence intervals (CIs) were calculated to evaluate miRNAs prognostic values. A total of 20 studies investigating serum miRNAs were included in this meta-analysis; the initial terminal point of these reports included overall survival (OS), progression-free survival (PFS), disease-free survival (DFS), and recurrence-free survival (RFS). For prognostic meta-analyses, the pooled HR for terminal events of higher expression of miRNAs and lower expression of miRNAs were 5.68 (95% CI 4.73-6.82, P < 0.05) and 3.78 (95% CI 3.27-4.37, P < 0.05), respectively. Additionally, subgroup analyses were conducted based on the analysis methods applied and clinicopathological features reported. In the pooled analyses, the miRNA expression levels are associated with poor prognosis according to both univariate and multivariate analyses. Furthermore, serum miRNAs (miRNA-195, miRNA-27a, miRNA-191, miRNA-300, miRNA-326, miRNA-497, miRNA-95-3p, miRNA-223, miRNA-491-5p, miRNA-124, miRNA-101, miRNA-139-5p, miRNA-194) were associated with poor OS and found to be closely correlated with clinical stage and distant metastasis in osteosarcoma. The results illustrate that low or high expression of these specific miRNAs are both potentially useful as prognostic serum biomarkers in osteosarcoma, and miRNAs (miRNA-195, miRNA-27a, miRNA-191, miRNA-300, miRNA-326, miRNA-497, miRNA-95-3p, miRNA-223, miRNA-491-5p, miRNA-124, miRNA-101, miRNA-139-5p, miRNA-194) may indicate clinical stage and metastasis in this form of cancer.

Potential diagnostic value of miRNAs in peripheral blood for osteosarcoma: A meta-analysis

Osteosarcoma (OS) is one of the most common primary malignant tumors in adolescents. In recent years, multiple studies have reported the value of miRNAs in the diagnosis of OS, but the results were very different from each other. Therefore, we conducted this meta-analysis to determine the accuracy of miRNAs in the diagnosis of OS. The meta-analysis searched for relevant researches including PubMed, EMBASE, Web of Science, Wanfang database and China National Knowledge Infrastructure (CNKI) as of June 1, 2020. We used the quality assessment of Diagnostic Accuracy Study 2 (QUADAS-2) to score the quality of each study. A random effects model was used to pool the sensitivity and specificity. We measured the diagnostic value using positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR) and area under the curve (AUC). Subgroup and meta-regression analysis were used to find potential sources of heterogeneity. The meta-analysis finally included 31 articles about 2634 OS patients and 1715 healthy controls. The pooled estimations showed that the circulating miRNAs has a high accuracy in diagnosing OS, with a sensitivity of 0.79, specificity of 0.89, PLR of 7.3, NLR of 0.23, DOR of 31, and AUC of 0.90. In addition, subgroup and meta-regression analysis showed that miRNA clusters have higher diagnostic accuracy than single miRNA, and miRNAs in plasma were more reliable than those in serum. In conclusion, peripheral blood miRNA is a potential noninvasive biomarker to assist in the early diagnosis of OS, especially young patients with bone pain and/or indeterminate radiology findings.

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.

The current state of MiRNAs as biomarkers and therapeutic tools

MicroRNAs (miRNAs) are non-coding RNAs with a length of 18-22 nucleotides that regulate about a third of the human genome at the post-transcriptional level. MiRNAs are involved in almost all biological processes, including cell proliferation, apoptosis, and cell differentiation, but also play a key role in the pathogenesis of many diseases. Most miRNAs are expressed within the cells themselves. Due to various forms of transport from cells like exosomes, circulating miRNAs are stable and can be found in human body fluids, such as blood, saliva, cerebrospinal fluid, and urine. Circulating miRNAs are of great interest as potential noninvasive biomarkers for tumors, lipid disorders, diabetes mellitus, and cardiovascular diseases. However, the possibility of their use in the clinic is limited, and this is associated with a number of problems since currently there are significant differences between the procedures for processing samples, methods of analysis, and especially strategies for standardizing results. Moreover, miRNAs can represent not only potential biomarkers but also become new therapeutic agents and be used in modern clinical practice, which again confirms the need for their study.

Apatinib as targeted therapy for advanced bone and soft tissue sarcoma: a dilemma of reversing multidrug resistance while suffering drug resistance itself

Bone and soft tissue sarcomas are rare malignant tumors originated from mesenchymal tissues. They harbor more than 50 distinct subtypes and differ in pathological features and clinical courses. Despite the significant improvements in modern multi-modality treatment, the outcomes and overall survival rates remain poor for patients with advanced, refractory, metastatic, or relapsed diseases. The growth and metastasis of bone and soft tissue sarcoma largely depend on angiogenesis, and VEGF/VEGFR pathway is considered as the most prominent player in angiogenesis. Therefore, blockade of VEGF/VEGFR pathways is a promising therapeutic strategy to retard neovascularization. Several VEGFR inhibitors have been developed and revealed their favorable anti-neoplastic effects in various cancers, but such desirable anti-tumor effects are not obtained in advanced sarcomas because of multiple reasons, such as drug tolerance, short duration of response, and severe adverse effects. Fortunately, preclinical and clinical studies have indicated that apatinib is a novel promising VEGFR2 inhibitor showing potent anti-angiogenic and anti-neoplastic activities in advanced sarcomas. Especially, apatinib has showed notable characteristics in multidrug resistance reversal, tumor regression, vascular normalization, immunosuppression alleviation, and enhancement of chemotherapeutic and radiotherapeutic effects. However, apatinib also gets struck in dilemma of reversing multidrug resistance of chemotherapeutic agents while suffering drug resistance itself, and several difficulties should be tackled before full use of apatinib. In this review, we discuss the outstanding characteristics and main predicaments of apatinib as targeted therapy in advanced sarcomas. Bone and soft tissue sarcomas are rare but malignant tumors originated from mesenchymal tissues. They harbor more than 100 distinct subtypes and differ in features of pathologies and clinical courses. Despite the significant improvements in modern multi-modality treatment, the outcomes and overall survival rates remain poor for patients with advanced, refractory, metastatic, or relapsed lesions. The growth and metastasis of bone and soft tissue sarcoma largely depend on angiogenesis and VEGF/VEGFR pathways play a pivotal role in angiogenesis. Therefore, blockade of VEGF/VEGFR pathways is a promising therapeutic strategy. Several VEGFR inhibitors have been developed and verified in clinical trials but with unfavorable outcomes. Fortunately, preclinical studies and clinical trials have indicated that apatinib is a novel promising VEGFR2 inhibitor showing potent anti-angiogenic and anti-neoplastic activities in advanced sarcomas. Actually, apatinib has showed notable characteristics in multidrug resistance reversal, tumor regression, vascular normalization, immunosuppression alleviation, enhancement of chemotherapeutic and radiotherapeutic effects. However, apatinib also gets struck in dilemma of reversing multidrug resistance of chemotherapeutic agents while suffering drug resistance itself, and several difficulties should be tackled before full use of apatinib. In this review, we discuss the outstanding characteristics and main predicaments of apatinib as targeted therapy in advanced sarcomas.

Biomarkers for pediatric cancer detection: latest advances and future perspectives

Cancer is one of the major health problems of the modern world. With the development of novel biochemistry and analytical instrumentation, precancer diagnosis has become a major focus of clinical and preclinical research. Finding appropriate biomarkers is crucial to make an early diagnosis, before the disease fully develops. With the improvement of precancer studies, cancer biomarkers prove their usefulness in providing important data on the cancer type and the status of patients' progression at a very early stage of the disease. Due to the constant evolution of pediatric cancer diagnosis, which includes highly advanced molecular techniques, the authors have decided to focus on selected groups of neoplastic disease and these include brain tumors, neuroblastoma, osteosarcoma and Hodgkin lymphoma.

Restoration of microRNA-197 expression suppresses oncogenicity in fibrosarcoma through negative regulation of RAN

MicroRNAs (miRNAs) act as crucial regulators of biological pathways/processes by reinforcing transcriptional programs and moderating transcripts. Emerging evidences have shown the involvement of dysregulated miRNAs in pathophysiology of human diseases including several cancer types. Recently, miR-197-3p has been reported to play different roles in different cancers; however, its role in fibrosarcoma, a highly aggressive and malignant soft tissue sarcoma originated from the mesenchymal tissues, has not yet been studied. Therefore, this study aims to investigate the possible regulatory roles of miR-197-3p in the oncogenicity of fibrosarcoma. For this, we initially performed qRT-PCR of miR-197-3p, which we found to be downregulated in HT1080 human fibrosarcoma cells compared with IMR90-tert normal fibroblast cells. Subsequently, we performed gain-of-function study by employing several methods such as MTT assay, clonogenic assay, wound healing, flow cytometry cell cycle analysis, and acridine orange staining after transfecting HT1080 cells with miR-197-3p mimic. From these assays, we observed that miR-197-3p significantly inhibits viability, colony forming, and migration ability as well as triggers G2/M phase cell cycle arrest and autophagy in fibrosarcoma cells. To understand the mechanism through which miRNA performs these functions, we predicted its targets using TargetScan and performed pathway enrichment analysis after screening them by their expression in fibrosarcoma. Among the enriched targets, we found RAN (ras-related nuclear protein) to be a crucial target through which miR-197-3p represses tumorigenesis by binding to its 3´ UTR, validated by luciferase reporter assay. The tumor suppressive role of the miRNA was further confirmed by transfecting its mimic in RAN-overexpressed cells which showed significant attenuation in tumorigenic effect of RAN in fibrosarcoma as seen in different assays. Taken together, our study unveiled that miR-197-3p acts as an oncosuppressor in fibrosarcoma through G2/M phase arrest and induction of autophagy, and raises the possibility to act as a novel therapeutic intervention for the malignancy.

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.

Circulating miRNAs as Diagnostic and Prognostic Biomarkers in Common Solid Tumors: Focus on Lung, Breast, Prostate Cancers, and Osteosarcoma

An early cancer diagnosis is essential to treat and manage patients, but it is difficult to achieve this goal due to the still too low specificity and sensitivity of classical methods (imaging, actual biomarkers), together with the high invasiveness of tissue biopsies. The discovery of novel, reliable, and easily collectable cancer markers is a topic of interest, with human biofluids, especially blood, as important sources of minimal invasive biomarkers such as circulating microRNAs (miRNAs), the most promising. MiRNAs are small non-coding RNAs and known epigenetic modulators of gene expression, with specific roles in cancer development/progression, which are next to be implemented in the clinical routine as biomarkers for early diagnosis and the efficient monitoring of tumor progression and treatment response. Unfortunately, several issues regarding their validation process are still to be resolved. In this review, updated findings specifically focused on the clinical relevance of circulating miRNAs as prognostic and diagnostic biomarkers for the most prevalent cancer types (breast, lung, and prostate cancers in adults, and osteosarcoma in children) are described. In addition, deep analysis of pre-analytical, analytical, and post-analytical issues still affecting the circulation of miRNAs' validation process and routine implementation is included.

Tumour-Derived Extracellular Vesicles (EVs): A Dangerous "Message in A Bottle" for Bone

Several studies have shown the importance of Extracellular Vesicles (EVs) in the intercellular communication between tumour and resident cells. Through EVs, tumour cells can trigger cell-signalling molecules and shuttle exogenous information to target cells, thus promoting spread of the disease. In fact, many processes are fuelled by EVs, such as tumour invasion and dormancy, drug-resistance, immune-surveillance escape, extravasation, extracellular matrix remodelling and metastasis. A key element is certainly the molecular profile of the shed cargo. Understanding the biochemical basis of EVs would help to predict the ability and propensity of cancer cells to metastasize a specific tissue, with the aim to target the release of EVs and to manipulate their content as a possible therapeutic approach. Moreover, EV profiling could help monitor the progression of cancer, providing a useful tool for more effective therapy. This review will focus on all the EV-mediated mentioned mechanisms in the context of both primary bone cancers and bone metastases.

Noncoding RNAs in Extracellular Fluids as Cancer Biomarkers: The New Frontier of Liquid Biopsies

The last two decades of cancer research have been devoted in two directions: (1) understanding the mechanism of carcinogenesis for an effective treatment, and (2) improving cancer prevention and screening for early detection of the disease. This last aspect has been developed, especially for certain types of cancers, thanks also to the introduction of new concepts such as liquid biopsies and precision medicine. In this context, there is a growing interest in the application of alternative and noninvasive methodologies to search for cancer biomarkers. The new frontiers of the research lead to a search for RNA molecules circulating in body fluids. Searching for biomarkers in extracellular body fluids represents a better option for patients because they are easier to access, less painful, and potentially more economical. Moreover, the possibility for these types of samples to be taken repeatedly, allows a better monitoring of the disease progression or treatment efficacy for a better intervention and dynamic treatment of the patient, which is the fundamental basis of personalized medicine. RNA molecules, freely circulating in body fluids or packed in microvesicles, have all the characteristics of the ideal biomarkers owing to their high stability under storage and handling conditions and being able to be sampled several times for monitoring. Moreover, as demonstrated for many cancers, their plasma/serum levels mirror those in the primary tumor. There are a large variety of RNA species noncoding for proteins that could be used as cancer biomarkers in liquid biopsies. Among them, the most studied are microRNAs, but recently the attention of the researcher has been also directed towards Piwi-interacting RNAs, circular RNAs, and other small noncoding RNAs. Another class of RNA species, the long noncoding RNAs, is larger than microRNAs and represents a very versatile and promising group of molecules which, apart from their use as biomarkers, have also a possible therapeutic role. In this review, we will give an overview of the most common noncoding RNA species detectable in extracellular fluids and will provide an update concerning the situation of the research on these molecules as cancer biomarkers.

miR‑195 suppresses metastasis and angiogenesis of squamous cell lung cancer by inhibiting the expression of VEGF

MicroRNAs (miRNAs) are small, noncoding RNAs that are ~22 nucleotides in length. Accumulating evidence has revealed that miRNAs act as oncogenes or tumor suppressors in various human cancers. In order to investigate the role of miR-195- in squamous cell lung cancer (SQCLC) cells, and to determine the underlying mechanism, the present study utilized RT-qPCR, western blot analysis, luciferase assay, MTT assay, cell migration assay, and in vitro angiogenesis techniques. The results obtained revealed that miR-195-5p acted as a tumor suppressor in SQCLC cells. The expression levels of miR-195 were decreased in two SQCLC cell lines (H520 and SK-Mes-1) compared with a normal lung cell line, and miR-195 directly targeted the 3′-untranslated region of vascular endothelial growth factor (VEGF) in SQCLC cells. Additionally, miR-195 upregulation suppressed the viability and migration of SQCLC cells. Furthermore, miR-195 inhibited the growth and tube formation of endothelial vascular cells. Collectively, the findings indicated that miR-195 downregulated VEGF, and that targeting this miRNA may provide an effective approach to inhibit angiogenesis in tumors.

miR-195 contributes to human osteoarthritis via targeting PTHrP

The dysregulated expression of the osteoarthritis (OA)-related genes in cartilage, such as matrix metalloproteinase 13 (MMP-13) and type X collagen (Col X), facilitates the onset and progression of OA. Reduced parathyroid hormone-related protein (PTHrP) may also accelerate this progression. Furthermore, miRNAs, endogenous regulators of mRNAs, are thought to play key roles in the pathogenesis of OA. In this study, we found that miR-195 levels were significantly upregulated in OA tissue, while PTHrP mRNA/protein expression was substantially downregulated, and there was a negative correlation between miR-195 and PTHrP. Upregulated miR-195 strongly inhibited Aggrecan, type II collagen (Col II) mRNA/protein expression, while it enhanced the expression of MMP-13 and Col X at mRNA/protein level; conversely, downregulated miR-195 significantly increased Col II mRNA/protein expression, while it decreased the expression of MMP-13 and Col X mRNA/protein. Moreover, our study demonstrated that PTHrP is a novel target of miR-195 using dual luciferase reporter assay. Finally, miR-195-mediated changes of Col II and OA-related genes were substantially attenuated by siRNA_PTHrP treatment. These results suggested that miR-195 is involved in the pathogenesis of OA via PTHrP.

LncRNA Linc00511 promotes osteosarcoma cell proliferation and migration through sponging miR-765

Long noncoding RNA (lncRNA) Linc00511 is a novel lncRNA, and it was reported to play important roles in the progression and carcinogenesis of several tumors. However, the expression and biological roles of Linc00511 in osteosarcoma were still unknown. In this research, we showed that the expression of Linc00511 was upregulated in osteosarcoma samples and cell lines. Ectopic expression of Linc00511 promoted osteosarcoma cell growth, colony formation, and migration. Moreover, overexpression of Linc00511 enhanced the epithelial-mesenchymal transition progression in osteosarcoma cell. In addition, we showed that elevated expression of Linc00511 suppressed microRNA-765 (miR-765) expression and promoted apurinic/apyrimidinic endonuclease 1 (APE1) expression in osteosarcoma cell. The expression of miR-765 was downregulated in osteosarcoma cells and samples and was negatively related to Linc00511 expression in osteosarcoma tissues. Ectopic expression of miR-765 inhibited osteosarcoma cell growth and migration. Furthermore, we showed that Linc00511 overexpression promoted MG-63 cells proliferation, colony formation, and migration via downregulation of miR-765. These results suggested that Linc00511 played as an oncogene in the development of osteosarcoma.

Exosomes in sarcomas: Tiny messengers with broad implications in diagnosis, surveillance, prognosis and treatment

Exosomes are cell-secreted extracellular vesicles, which contain an array of biomolecules, such as proteins, mRNAs, microRNAs, and lipids, take part in intercellular communication and mediate tumor-host interactions. They are increasingly considered as a source of biomarkers for liquid biopsies as well as potential drug vectors. Sarcomas are rare malignant mesenchymal tumours and due to their relative rarity exosomes have not been investigated in as extensively as in epithelial malignancies. Nonetheless, valuable information has been gathered over the last years on the roles of exosomes in sarcomas. In the present review we summarize all relevant data obtained so far from cell lines, animal models and patients with emphasis on their potential clinical utility.

Noncoding RNAs as circulating biomarkers in osteosarcoma patients

Noncoding RNAs (ncRNAs) identify a large family of RNAs that do not encode proteins and represent an important group of tumor biomarkers, directly involved in the process of tumor pathogenesis and progression. Many of them have also been identified in biological fluids of patients with cancer, especially blood, suggesting their role as an emerging class of circulating biomarkers. Many ncRNAs, both miRNAs and lncRNAs, are deregulated in sarcoma tissues, with the most consistent data in osteosarcomas. In patients with osteosarcoma, the role of ncRNAs as circulating biomarkers is taking enormous value, above all for their ability to vary expression levels during disease progression and in response to therapy. In this mini-review, we summarize the main studies supporting the role of circulating ncRNAs in monitoring disease status in patients with osteosarcoma.

MicroRNA-Based Diagnosis and Treatment of Metastatic Human Osteosarcoma

Osteosarcoma is a malignant tumor of the bones that commonly occurs in young individuals. The 5-year survival rate of osteosarcoma patients is 60-70%. Metastasis to the lungs leads to death in 30-40% of osteosarcoma patients. Therefore, the development of effective strategies for early detection and treatment of this disease are important to improve the survival of osteosarcoma patients. However, metastatic markers for osteosarcoma and molecules that might be targeted for the treatment of metastatic osteosarcoma have not been identified yet. Therefore, the mechanism of metastasis to the lungs needs to be explored from a novel viewpoint. Recently, the aberrant expression of microRNAs (miRNAs) has been reported to be involved in the carcinogenesis and cancer progression of many cancers. Furthermore, miRNAs in the blood have been reported to show an aberrant expression unique to several cancers. Therefore, miRNAs are gaining attention as potential diagnostic markers for cancers. On the other hand, normalizing the dysregulated expression of miRNAs in cancer cells has been shown to alter the phenotype of cancer cells, and thus treatment strategies targeting miRNAs are also being considered. This review summarizes the abnormality of miRNA expression associated with the metastasis of osteosarcoma and describes the present situation and issues regarding the early diagnosis and development of treatment strategies for metastatic osteosarcoma based on the current understanding of this disease.

An Insight into the Roles of MicroRNAs and Exosomes in Sarcoma

Sarcomas are rare solid tumors, but at least one-third of patients with sarcoma die from tumor-related disease. MicroRNA (miRNA) is a noncoding RNA that regulates gene expression in all cells and plays a key role in the progression of cancers. Recently, it was identified that miRNAs are transferred between cells by enclosure in extracellular vesicles, especially exosomes. The exosome is a 100 nm-sized membraned vesicle that is secreted by many kinds of cells and contains miRNA, mRNA, DNA, and proteins. Cancer uses exosomes to influence not only the tumor microenvironment but also the distant organ to create a premetastatic niche. The progression of sarcoma is also regulated by miRNAs and exosomes. These miRNAs and exosomes can be targeted as biomarkers and treatments. In this review, we summarize the studies of miRNA and exosomes in sarcoma.

Identification of Prognostic and Predictive Osteosarcoma Biomarkers

Both adolescents and children suffer from osteosarcoma, localized in the metaphysis of the long bones. This is the most common primary high-grade bone tumor in this patient group. Early tumor detection is the key to ensuring effective treatment. Improved osteosarcoma outcomes in clinical trials have been contingent on biomarker discovery and an evolving understanding of molecules and their complex interactions. In this review, we present a short overview of biomarkers for osteosarcoma, and highlight advances in osteosarcoma-related biomarker research. Many studies show that several biomarkers undergo critical changes with osteosarcoma progression. Growing knowledge about osteosarcoma-related markers is expected to positively impact the development of therapeutics for osteosarcoma, and ultimately of clinical care. It has also become important to develop new biomarkers, which can identify vulnerable patients who should be treated with more intensive and aggressive therapy after diagnosis.

Blood-borne biomarkers of osteosarcoma: A systematic review

Osteosarcoma is the most common type of primary malignant bone tumor in children and young adults. Development of clinically useful biomarkers has the potential to improve treatments. The aim of this review was to investigate the recent literature assessing the utility of biomarkers for osteosarcoma. A detailed literature search was performed, with hand searches for related research publications. The search was limited to publications in English between January 2007 and February 2017. Of 286 studies identified, 24 met the inclusion criteria. There is a wide range of osteosarcoma biomarkers identified which act as clinical prognostic factors in patient outcome.

Application of liquid biopsy in bone and soft tissue sarcomas: Present and future

Bone and soft tissue sarcomas account for approximately 1% of adult solid malignancies and 20% of pediatric solid malignancies. Sarcomas are divided into more than 50 subtypes. Each subtype is highly heterogeneous and characterized by significant morphological and phenotypic variability. Currently, sarcoma characterization is based on tissue biopsies. However, primary and invasive tissue biopsies may not accurately reflect the current disease condition following treatment as is may cause marked changes to the tumor cells. Liquid biopsy offers an alternative minimally invasive approach to provide dynamic tumor information, allowing for the application of precision medicine in the treatment of sarcomas. Recently, there have been numerous blood-based tumor components identified by liquid biopsy in sarcomas, including circulating tumor cells, circulating cell-free nucleic acids, tumor-derived exosomes and metabolites in circulation. Here, we summarize the current evolving technologies and then elaborate on emerging novel concepts that may further propel the field of liquid biopsy in sarcomas. We address the applications in the context of our current knowledge about liquid biopsy in sarcomas and highlight the potential of translating these recent advances into the clinic for more effective management strategies for sarcoma patients.

Identification of Novel Target for Osteosarcoma by Network Analysis

Background

Osteosarcoma (OS) is a highly complicated bone cancer involving imbalance of signaling transduction networks in cells. Development of new anti-osteosarcoma drugs is very challenging, mainly due to lack of known key targets.

Material/Method

In this study, we attempted to reveal more promising targets for drug design by “Target-Pathway” network analysis, providing the new therapeutic strategy of osteosarcoma. The potential targets used for the treatment of OS were selected from 4 different sources: DrugBank, TCRD database, dbDEMC database, and recent scientific literature papers. Cytoscape was used for the establishment of the “Target-Pathway” network.

Results

The obtained results suggest that tankyrase 2 (TNKS2) might be a very good potential protein target for the treatment of osteosarcoma. An in vitro MTT assay proved that it is an available option against OS by targeting the TNKS2 protein. Subsequently, cell cycle and apoptosis assay by flow cytometry showed the TNKS2 inhibitor can obviously induce cell cycle arrest, apoptosis, and mitotic cell death.

Conclusions

Tankyrase 2 (TNKS2), a member of the multifunctional poly(ADP-ribose) polymerases (PARPs), could be a very useful protein target for the treatment of osteosarcoma.

MiR-139-5p suppresses osteosarcoma cell growth and invasion through regulating DNMT1

BACKGROUND

Accumulating evidence has suggested the crucial roles of differentially expressed miRNAs in osteosarcoma progression. MiR-139-5p was decreased in various cancers. However, the role of miR-139-5p in the development of osteosarcoma and the underlying mechanism remain to be addressed.

METHODS

MiR-139-5p and DNA methyltransferase-1 (DNMT1) mRNA expressions in osteosarcoma tissues and cells were detected by qRT-PCR and western blot analysis. The effects of miR-139-5p and DNMT1 on osteosarcoma cell migration, invasion and epithelial-mesenchymal transition (EMT) were investigated through cell migration and invasion assays, and western blot analysis. The relationship between miR-139-5p and DNMT1was explored using luciferase reporter analysis and western blot. A xenograft tumor model was employed to verify the effects of miR-139-5p on osteosarcoma.

RESULTS

We found that miR-139-5p was strikingly decreased in osteosarcoma tissues and cell lines. MiR-139-5p over-expression suppressed osteosarcoma cell growth, migration and invasion, while loss of miR-139-5p promoted osteosarcoma cell proliferation, migration and invasion. Following, we characterized that DNMT1 was a direct target of miR-139-5p that interacted with the 3'-untranslated region of DNMT1. MiR-139-5p regulated a down-regulation in DNMT1 protein expression levels. We also found that DNMT1 expression was increased and negatively correlated with miR-139-5p expression in osteosarcoma tissues clinically. Xenograft tumor analysis suggested that miR-139-5p over-expression reduced tumor growth in osteosarcoma in vivo through decreasing DNMT1 expressions.

CONCLUSION

MiR-139-5p suppressed the osteosarcoma progression by reducing DNMT1, supplying new insight into the molecular mechanism uncovering osteosarcoma growth.

MiR-195 suppresses colon cancer proliferation and metastasis by targeting WNT3A

MicroRNAs (miRNAs) are a novel class of diagnostic and therapeutic target in cancer. Here, we aimed to explore the effects and mechanism of miR-195 regulation in colon cancer. The expressions of several putative miRNAs in colon tumors, compared to those in normal tissues, were investigated by bioinformatical analysis of a Gene Expression Omnibus database. Quantitative real-time PCR analysis (qRT-PCR) was used to validate the identified changes in normal tissues, primary tumors, and metastatic tumors. MTT, soft agar colony formation, and transwell assays were used to evaluate the effects of miR-195 overexpression or inhibition on cell viability, proliferation, migration, and invasion. Targets of miR-195 were identified by TargetScan, and subsequently verified by qRT-PCR and Western blot. The role of miR-195 in the β-catenin pathway was also studied using RT-PCR and Western blot. MiR-195 expression was downregulated in colon carcinoma tissues and negatively correlated with the metastatic potential. While transfecting miR-195 mimics decreased the proliferation, migration, and invasion of colon cancer cells, miR-195 inhibition exerted opposing effects. WNT3A was identified as a direct target of miR-195. β-catenin was also downregulated by miR-195 in colon cancers. MiR-195 downregulation is associated with the enhanced proliferation, migration, and invasion of colon cancer. MiR-195 directly downregulates WNT3A. Our results indicate that miR-195 is a potential diagnostic marker and therapeutic target for improving the clinical management of colon cancer.

Non-coding RNAs, the Trojan horse in two-way communication between tumor and stroma in colorectal and hepatocellular carcinoma

In a continuous and mutual exchange of information, cancer cells are invariably exposed to microenvironment transformation. This continuous alteration of the genetic, molecular and cellular peritumoral stroma background has become as critical as the management of primary tumor progression events in cancer cells. The communication between stroma and tumor cells within the extracellular matrix is one of the triggers in colon and liver carcinogenesis. All non- codingRNAs including long non-coding RNAs, microRNAs and ultraconserved genes play a critical role in almost all cancers and are responsible for the modulation of the tumor microenvironment in several malignant processes such as initiation, progression and dissemination. This review details the involvement of non codingRNAs in the evolution of human colorectal carcinoma and hepatocellular carcinoma in relationship with the microenvironment. Recent research has shown that a considerable number of dysregulated non- codingRNAs could be valuable diagnostic and prognostic biomarkers in cancer. Therefore, more in-depth knowledge of the role non- codingRNAs play in stroma-tumor communication and of the complex regulatory mechanisms between ultraconserved genes and microRNAs supports the validation of future effective therapeutic targets in patients suffering from hepatocellular and colorectal carcinoma, two distinctive entities which share quite a lot common non-coding RNAs.

Long non-coding RNA XIST promotes osteosarcoma progression by targeting YAP via miR-195-5p

The lncRNA XIST (X inactive-specific transcript) is an oncogenic lncRNA that is present in various malignant tumors; however, its role and molecular mechanisms in osteosarcoma (OS) progression remain unclear. In the current study, 40 pairs of OS tissues and matched adjacent non-tumor tissues were collected. qRT-PCR was conducted to investigate the differences in XIST expression in tissues and OS cell lines. The proliferation, invasion, and EMT status of OS cells after transfection were assessed with WST-1 assays, Transwell assays, and Western blot analysis, respectively. Whether miR-195-5p was a direct downstream target of XIST was verified by both bioinformatics target gene prediction and dual-luciferase report analysis. A mouse model was established to evaluate tumor proliferation in vivo. Our results demonstrated that XIST expression was significantly upregulated in OS tissues and cell lines and negatively correlated with clinical prognosis. XIST knockdown inhibited cancer cell proliferation and invasion in vitro, inhibited the EMT of OS cells in vitro, and suppressed subcutaneous tumor growth in vivo. Further analysis demonstrated that XIST regulated YAP expression by functioning as a competing endogenous RNA that sponged miR-195-5p in OS cells. XIST directly interacted with miR-195-5p and decreased the binding of miR-195-5p to the YAP 3'UTR, which suppressed the degradation of YAP mRNA by miR-195-5p. In conclusion, this work demonstrates that lncRNA XIST enhances OS cancer cell proliferation and invasion in part through the miR-195-5p/YAP pathway. Therefore, lncRNA XIST might be a promising therapeutic target for OS.

Circulating microRNA expression and their target genes in deep vein thrombosis: A systematic review and bioinformatics analysis

BACKGROUND

Clinically, D-dimer is the only established biomarker for the diagnosis of deep vein thrombosis (DVT). However, low specificity discounts its diagnostic value. Several publications have illustrated the differentially expressed circulating microRNAs (miRNAs) and their potential diagnostic values for DVT patients. Therefore, we systematically evaluated present researches and further performed bioinformatics analysis, to provide new insights into the diagnosis and underlying mechanisms of miRNAs in DVT.

METHODS

Databases PubMed, Web of Science, and Embase were searched from January 2000 to April 2017. Articles on circulating miRNAs expression in DVT were retrieved and reference lists were handpicked. Bioinformatics analysis was conducted for further evaluation.

RESULTS

Eventually, the eligibility criteria for inclusion in this study were met by 3 articles, which consisted of 13 specially expressed miRNAs and 149 putative target genes. Two representative KEGG pathways, vascular endothelial growth factor and phosphatidylinositol 3'-kinase (PI3K)-Akt signaling pathway, seemed to participate in the regulatory network of thrombosis.

CONCLUSIONS

Despite the potential diagnostic value and regulation effect, the results of circulating miRNAs used as biomarkers for DVT are not so encouraging. More in-depth and larger sample investigations are needed to explore the diagnostic and therapeutic values of miRNAs for DVT.

Downregulation of lncRNA CASC2 facilitates osteosarcoma growth and invasion through miR-181a

OBJECTIVES

Long non-coding RNA cancer susceptibility candidate 2 (CASC2) is a novel lncRNA and has been indicated as playing tumour suppressor gene in several tumours. However, the role of CASC2 in osteosarcoma is still uncovered.

MATERIALS AND METHODS

The CASC2 and miR-181a expressions were measured via qRT-PCR. CCK-8 assay and colony formation assay were performed to determine the cell growth, and transwell assay was performed to assess the cell invasion.

RESULTS

We showed that CASC2 expression was downregulated in osteosarcoma samples and cell lines. Moreover, we showed that downregulated expression of CASC2 was correlated with advanced TNM stage. Furthermore, overexpression of CASC2 inhibited osteosarcoma cell proliferation, colony formation, and invasion. In addition, we indicated that ectopic expression of CASC2 suppressed miR-181a expression and enhanced the expression of Ras association domain family member 6 (RASSF6), PTEN and ATM in osteosarcoma cell, which were the direct target gene of miR-181a. Moreover, we indicated that RASSF6 expression was downregulated in osteosarcoma samples and cell lines and downregulated expression of RASSF6 was correlated with advanced TNM stage. We found that the expression of RASSF6 was positively correlated with the expression of CASC2 in osteosarcoma tissues. Ectopic expression of CASC2 suppressed the osteosarcoma cell proliferation, colony formation and invasion through regulating RASSF6 expression.

CONCLUSIONS

Our data illuminated that CASC2 acted as a tumour suppressor in osteosarcoma progression.