Circulating miR-148a is a significant diagnostic and prognostic biomarker for patients with 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.

Circulating and extracellular vesicle-derived microRNAs as biomarkers in bone-related diseases

MicroRNAs (miRNA) are small non-coding RNA molecules that regulate posttranscriptional gene expression by repressing messengerRNA-targets. MiRNAs are abundant in many cell types and are secreted into extracellular fluids, protected from degradation by packaging in extracellular vesicles. These circulating miRNAs are easily accessible, disease-specific and sensitive to small changes, which makes them ideal biomarkers for diagnostic, prognostic, predictive or monitoring purposes. Specific miRNA signatures can be reflective of disease status and development or indicators of poor treatment response. This is especially important in malignant diseases, as the ease of accessibility of circulating miRNAs circumvents the need for invasive tissue biopsy. In osteogenesis, miRNAs can act either osteo-enhancing or osteo-repressing by targeting key transcription factors and signaling pathways. This review highlights the role of circulating and extracellular vesicle-derived miRNAs as biomarkers in bone-related diseases, with a specific focus on osteoporosis and osteosarcoma. To this end, a comprehensive literature search has been performed. The first part of the review discusses the history and biology of miRNAs, followed by a description of different types of biomarkers and an update of the current knowledge of miRNAs as biomarkers in bone related diseases. Finally, limitations of miRNAs biomarker research and future perspectives will be presented.

Detection of circulating tumor-derived material in peripheral blood of pediatric sarcoma patients: A systematic review

BACKGROUND

Detection of circulating tumor-derived material (cTM) in the peripheral blood (PB) of cancer patients has been shown to be useful in early diagnosis, prediction of prognosis, and disease monitoring. However, it has not yet been thoroughly evaluated for pediatric sarcoma patients.

METHODS

We searched the PubMed and EMBASE databases for studies reporting the detection of circulating tumor cells, circulating tumor DNA, and circulating RNA in PB of pediatric sarcoma patients. Data on performance in identifying cTM and its applicability in diagnosis, and evaluation of tumor characteristics, prognostic factors, and treatment response was extracted from publications.

RESULTS

A total of 79 studies were assigned for the present systematic review, including detection of circulating tumor cells (116 patients), circulating tumor DNA (716 patients), and circulating RNA (2887 patients). Circulating tumor cells were detected in 76% of patients. Circulating DNA was detected in 63% by targeted NGS, 66% by shallow WGS, and 79% by digital droplet PCR. Circulating RNA was detected in 37% of patients.

CONCLUSION

Of the cTM from Ewing's sarcoma and rhabdomyosarcoma ctDNA proved to be the best target for clinical application including diagnosis, tumor characterization, prognosis, and monitoring of disease progression and treatment response. For osteosarcoma the most promising targets are copy number alterations or patient specific micro RNAs, however, further investigations are needed to obtain consensus on clinical utility.

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.

Application of miRNA Biomarkers in Predicting Overall Survival Outcomes for Lung Adenocarcinoma

Background

With the development of research, the importance of microRNAs (miRNAs) in the occurrence, metastasis, and prognosis of lung adenocarcinoma (LUAD) has attracted extensive attention. This study is aimed at predicting overall survival (OS) results through bioinformatics to identify novel miRNA biomarkers and hub genes.

Materials and Methods

The data of LUAD-related miRNA and mRNA samples was downloaded from The Cancer Genome Atlas (TCGA) database. Upon screening and pretreatment of initial data, TCGA data were analyzed using R platform and a series of analytical tools to identify biomarkers with high specificity and sensitivity.

Results

7 miRNAs and 13 hub genes that had strong relation to the overall surviving status were identified in patients with LUAD. The expression of seven miRNAs (hsa-miR-19a-3p, hsa-miR-126-5p, hsa-miR-556-3p, hsa-miR-671-5p, hsa-miR-937-3p, hsa-miR-4664-3p, and hsa-miR-4746-5p) could apparently improve the OS rate of patient with LUAD. The 13 hub genes, namely, CCT6A, CDK5R1, CEP55, DNAJB4, EGLN3, HDGF, HOXC8, LIMD1, MKI67, PCP4L1, PPIL1, SCAI, and STK32A, showed a correlation with the OS status.

Conclusion

7 miRNAs were identified as novel biomarkers for the prognosis of patients with LUAD. This study offered a deeper comprehension of LUAD treatment and prognosis from the molecular level and helped enhance the understanding of the pathogenesis and potential molecular events of LUAD.

CircRNA 0009043 suppresses non-small-cell lung cancer development via targeting the miR-148a-3p/DNAJB4 axis

Background

Circular RNAs (circRNAs) are important regulators of the development and progression of non-small-cell lung cancer (NSCLC) and many other malignancies. The functional importance of circ_0009043 in NSCLC, however, has yet to be established.

Methods

The expression of circ_0009043, miR-148a-3p, and DnaJ heat shock protein family (Hsp40) member B4 (DNAJB4) in NSCLC cells was assessed via qPCR. The proliferative activity of these cells was examined through EdU uptake and CCK-8 assays, while flow cytometry approaches were used to examine apoptotic cell death rates. Protein expression was measured through Western immunoblotting. Interactions between miR-148a-3p and circ_0009043 or DNAJB4 were detected through RNA immunoprecipitation (RIP) and dual-luciferase reporter assays. The in vivo importance of circ_0009043 as a regulator of oncogenic activity was assessed using murine xenograft models.

Results

Both NSCLC cells and tissue samples were found to exhibit circ_0009043 upregulation, and lower circ_0009043 expression levels were found to be related to poorer NSCLC patient overall survival. Knocking down circ_0009043 resulted in the enhancement of NSCLC cell proliferative activity and the suppression of apoptotic tumor cell death in vitro, while also driving more rapid in vivo tumorigenesis. Mechanistically, circ_0009043 was found to function as a molecular sponge that sequestered miR-148a-3p, which was in turn able to directly suppress DNAJB4 expression. When miR-148a-3p was overexpressed, this reversed the impact of knocking down circ_0009043 on the apoptotic death and proliferation of NSCLC cells. Conversely, miR-148a-3p inhibition resulted in the suppression of NSCLC cell apoptosis and the enhancement of tumor cell growth, while the downregulation of DNAJB4 reversed these changes.

Conclusion

Circ_0009043 acts as a tumor suppressor in NSCLC cells, promoting DNAJB4 upregulation via the sequestration of miR-148a-3p.

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.

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.

Development of a novel necroptosis-associated miRNA risk signature to evaluate the prognosis of colon cancer patients

BACKGROUND

Necroptosis is a recently discovered caspase-independent form of cell death which plays an important role in the occurrence and development of cancer. As an important regulatory factor in necroptosis, microRNAs (miRNAs) are important for the development of colon cancer. This study established a novel necroptosis-related miRNA risk signature to evaluate the prognosis of patients with colon adenocarcinoma (COAD).

METHODS

The necroptosis-related miRNAs were selected by assessing the differential expression of miRNAs in 459 COAD patient samples and 8 control samples from The Cancer Genome Atlas (TCGA). Selection operator Cox analyses and survival analyses were used to establish the risk signature of 7 miRNAs related to necroptosis. Functional enrichment analysis and nomograms were used to explore the potential effects of necroptosis-related miRNAs on prognosis and metastasis. The target genes of the necroptosis-related miRNAs were predicted using online databases and the genes related to overall survival (OS) were screened.

RESULTS

The risk signature was based on 7 necroptosis-related miRNAs. Nomograms showed that the risk signature was effective at predicting the prognosis and TNM stage of COAD patients. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses demonstrated that these miRNAs play an important role in cancer development, metastasis, and prognosis. A total of 38 target genes for these miRNAs were found to be associated with the OS in COAD patients.

CONCLUSIONS

This study provided novel evidence that necroptosis-related miRNAs are associated with the prognosis of COAD patients. A risk signature established based on these miRNAs could effectively predict the prognosis and metastasis of COAD in patients.

miR-148a, miR-152 and miR-200b promote prostate cancer metastasis by targeting DNMT1 and PTEN expression

MicroRNAs (miRs) modulate the expression of target genes in the signal pathway on transcriptome level. The present study investigated the ‘epigenetic-based miRNA (epi-miRNA)-mRNA’ regulatory network of miR-34b, miR-34c, miR-148a, miR-152, miR-200a and miR-200b epi-miRNAs and their target genes, DNA methyltransferase (DNMT1, 3a and 3b), phosphate and tensin homolog (PTEN) and NK3 Homeobox 1 (NKX3.1), in prostate cancer (PCa) using reverse transcription-quantitative PCR. The expression level of NKX3.1 were not significantly different between the PCa, Met-PCa and control groups. However, in the PCa and Met-PCa groups, the expression level of DNMT1 was upregulated, while DNMT3a, DNMT3b and PTEN were downregulated. Overexpression of DNMT1 (~5 and ~6-fold increase in the PCa and Met-PCa groups respectively) was accompanied by a decreased expression in PTEN, indicating a potential negative association. Both groups indicated that a high level of DNMT1 is associated with the aggressiveness of cancer, and there is a a directly proportional relationship between this gene and PSA, GS and TNM staging. A significant ~2 to ~5-fold decrease in the expression levels of DNMT3a and DNMT3b was found in both groups. In the PCa group, significant associations were identified between miR-34b and DNMT1/DNMT3b; between miR-34c/miR-148a and all target genes; between miR-152 and DNMT1/DNMT3b and PTEN; and between miR-200a/b and DNMT1. In the Met-PCa group, miR-148a, miR-152 and miR-200b exhibited a significant association with all target genes. A significant negative association was identified between PTEN and DNMT1 in the Met-PCa group. It was also revealed that that miR-148a, miR-152 and miR-200b increased the expression of DNMT1 and suppressed PTEN. Furthermore, the ‘epi-miRNA-mRNA’ bidirectional feedback loop was emphasised and the methylation pattern in PCa anti-cancer therapeutics was highlighted.

miR-148a-3p suppresses the progression of acute myeloid leukemia via targeting cyclin-dependent kinase 6 (CDK6)

To study the regulation of miR-148a-3p on CDK6 and its mechanism in the progress of acute myeloid leukemia (AML), differential miRNAs were analyzed by bioinformatics, and the miR-148a-3p levels in AML cell lines were detected. Results showed that miR-148a-3p played a crucial role in AML, and the level was lower in AML cells, especially in J111 and KG-1a cells. In J111 and KG-1a cells, the up-regulation of miR-148a-3p mimics blocked the cell growth by arresting cell cycle at G2/M and enhancing cell apoptosis. Transwell and EMT markers detection indicated that miR-148a-3p reduced the cell migration and invasion. Afterward, through bioinformatics analysis, it showed that the CDK6 is one of the direct target genes of miR-148a-3p. DLR assay confirmed the target regulation. CDK6 overexpression reversed the effects of miR-148a-3p on AML cells. Collectively, miR-148a-3p inhibited the process of AML cells through disturbing the CDK-6 expression, implying that the trageting miR-148a-3p might be regarded as effective therapy of AML.

Identification of plasma microRNA-22 as a marker for the diagnosis, prognosis, and chemosensitivity prediction of osteosarcoma

Objective

MicroRNA (miR)-22 plays crucial roles in malignant tumors and is involved in regulation of chemosensitivity. Additionally, altered expression of circulating miR-22 has been reported in various cancers. This study was designed to investigate plasma miR-22 expression in patients with osteosarcoma (OS) and determine its diagnostic, prognostic, and chemosensitivity prediction value.

Methods

Plasma miR-22 levels in 120 patients with OS and 120 healthy controls were detected by real-time quantitative reverse transcription PCR. Associations of plasma miR-22 expression with the patients’ clinicopathological features and prognosis were then assessed.

Results

Plasma miR-22 levels in patients with OS were significantly lower than those in healthy controls. Low plasma miR-22 levels were correlated with large tumor size, advanced clinical stages, positive distant metastasis, and poor tumor response to preoperative chemotherapy. Plasma miR-22 could discriminate OS patients from controls and distinguish patients with a good response to therapy from those with a poor response to therapy. Multivariate analysis revealed that low plasma miR-22 expression was a significant independent predictor of unfavorable prognosis.

Conclusions

Altered plasma levels of miR-22 might serve as a novel, noninvasive biomarker for OS diagnosis, prognosis, and chemosensitivity prediction.

Aberrant expression of miR-148a-3p in Alzheimer's disease and its protective role against amyloid-β induced neurotoxicity

OBJECTIVE

The current study investigated the expression change and clinical value of miR-148a-3p in AD patients, and further examined the role of miR-148a-3p in Aβ-induced neurotoxicity in SH-SY5Y cells.

MATERIAL AND METHODS

qRT-PCR was used for the measurement of miR-148a-3p expression levels. ROC curve was established to calculate the diagnostic value of serum miR-148a-3p for AD. CCK-8 and flow cytometry assay was applied for the detection of cell viability and apoptosis. Additionally, the luciferase reporter assay was performed to confirm the target relationship between ROCK1 and miR-148a-3p.

RESULTS

Serum miR-148a-3p was downregulated in AD patients compared with that in healthy controls, and was positively associated with the MMSE score in AD patients. Serum miR-148a-3p had the potential to distinguish AD patients from healthy controls, and the diagnostic sensitivity and specificity were respectively 85.5 % and 87.0 % at a cutoff value of 0.827. MiR-148a-3p attenuated Aβ25-35 induced neurotoxicity in SH-SY5Y cells, and ROCK1 was the target gene.

CONCLUSION

Serum miR-148a-3p is correlated with MMSE score in AD patients, and it might be helpful for the AD diagnosis. Overexpression of miR-148a-3p attenuated Aβ induced neurotoxicity in AD by targeting ROCK1.

The role of microRNAs in the osteogenic and chondrogenic differentiation of mesenchymal stem cells and bone pathologies

Mesenchymal stem cells (MSCs) have been identified in many adult tissues. MSCs can regenerate through cell division or differentiate into adipocytes, osteoblasts and chondrocytes. As a result, MSCs have become an important source of cells in tissue engineering and regenerative medicine for bone tissue and cartilage. Several epigenetic factors are believed to play a role in MSCs differentiation. Among these, microRNA (miRNA) regulation is involved in the fine modulation of gene expression during osteogenic/chondrogenic differentiation. It has been reported that miRNAs are involved in bone homeostasis by modulating osteoblast gene expression. In addition, countless evidence has demonstrated that miRNAs dysregulation is involved in the development of osteoporosis and bone fractures. The deregulation of miRNAs expression has also been associated with several malignancies including bone cancer. In this context, bone-associated circulating miRNAs may be useful biomarkers for determining the predisposition, onset and development of osteoporosis, as well as in clinical applications to improve the diagnosis, follow-up and treatment of cancer and metastases. Overall, this review will provide an overview of how miRNAs activities participate in osteogenic/chondrogenic differentiation, while addressing the role of miRNA regulatory effects on target genes. Finally, the role of miRNAs in pathologies and therapies will be presented.

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.

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.

Progress toward liquid biopsies in pediatric solid tumors

Pediatric solid tumors have long been known to shed tumor cells, DNA, RNA, and proteins into the blood. Recent technological advances have allowed for improved capture and analysis of these typically scant circulating materials. Efforts are ongoing to develop "liquid biopsy" assays as minimally invasive tools to address diagnostic, prognostic, and disease monitoring needs in childhood cancer care. Applying these highly sensitive technologies to serial liquid biopsies is expected to advance understanding of tumor biology, heterogeneity, and evolution over the course of therapy, thus opening new avenues for personalized therapy. In this review, we outline the latest technologies available for liquid biopsies and describe the methods, pitfalls, and benefits of the assays that are being developed for children with extracranial solid tumors. We discuss what has been learned in several of the most common pediatric solid tumors including neuroblastoma, sarcoma, Wilms tumor, and hepatoblastoma and highlight promising future directions for the field.

Knockdown of Kinesin Family 15 Inhibits Osteosarcoma through Suppressing Cell Proliferation and Promoting Cell Apoptosis

Kinesin family (KIF) members have vital roles in mitosis, meiosis, and transport of macromolecules in eukaryotic cells. In this study, we aimed to investigate the role of KIF15 in osteosarcoma. Immunohistochemical staining was performed to determine expression levels of KIF15 in osteosarcoma tissues and adjacent normal tissues. Tissue microarray analysis showed a correlation between the expression of KIF15 and pathological features of patients. Subsequently, lentivirus was used to inhibit the expression of KIF15 in osteosarcoma cells. An MTT assay was performed to examine cell proliferation. Transwell and wound healing assays were used to estimate the invasion and migration of osteosarcoma cells, respectively. Flow cytometric analysis was employed to define the apoptosis of osteosarcoma cells. Our results showed that KIF15 expression was significantly upregulated in osteosarcoma tissues compared with adjacent normal tissues. The Mann-Whitney U test and Spearman correlation analysis showed that the expression levels of KIF15 in osteosarcoma tissues were positively correlated with tumor infiltrate, a pathological characteristic of patients. The expression of KIF15 was successfully suppressed by shKIF15, and the knockdown efficiency reached 80 and 69% in MNNG/HOS and U2OS cells, respectively. Subsequently, knockdown of KIF15 significantly inhibited the capacity of cell proliferation, colony formation, invasion, and migration, but enhanced G2 phase arrest and partially enhanced cell apoptosis. This study preliminarily showed KIF15 to be a critical regulatory molecule involved in osteosarcoma cell proliferation. Consequently, KIF15 can be a potential diagnostic and therapeutic target for osteosarcoma.

Using Liquid Biopsy in the Treatment of Patient with OS

Liquid biopsies encompass a number of new technologies designed to derive tumor data through the minimally invasive sampling of an accessible body fluid. These technologies remain early in their clinical development, and applications for patients with osteosarcoma are actively under investigation. In this chapter, we outline the current state of liquid biopsy technologies as they apply to cancer generally and osteosarcoma specifically, focusing on assays that detect and profile circulating tumor DNA (ctDNA), microRNAs (miRNA), and circulating tumor cells (CTCs). At present, ctDNA assays are the most mature, with multiple assays demonstrating the feasibility of detecting and quantifying ctDNA from blood samples of patients with osteosarcoma. Initial studies show that ctDNA can be detected in the majority of patients with osteosarcoma and that the detection and level of ctDNA correlates with a worse prognosis. Profiling of ctDNA can also identify specific somatic events that may have prognostic relevance, such as 8q gain in osteosarcoma. miRNAs are stable RNAs that regulate gene expression and are known to be dysregulated in cancer, and patterns of miRNA expression have been evaluated in multiple studies of patients with osteosarcoma. While studies have identified differential expression of many miRNAs in osteosarcomas compared to healthy controls, a consensus set of prognostic miRNAs has yet to be definitively validated. Recent studies have also demonstrated the feasibility of capturing CTCs in patients with osteosarcoma. The development of assays that quantify and profile CTCs for use as prognostic biomarkers or tools for biologic discovery is still in development. However, CTC technology holds incredible promise given the potential to perform multi-omic approaches in single cancer cells to understand osteosarcoma heterogeneity and tumor evolution. The next step required to move liquid biopsy technologies closer to helping patients will be wide-scale collection of patient samples from large prospective studies.

Long Non-Coding RNA HOXA11-AS Promotes Non-Small Cell Lung Cancer Tumorigenesis Through microRNA-148a-3p/DNMT1 Regulatory Axis

OBJECTIVE

Our present study aimed to further investigate the molecular basis of long non-coding RNA homeobox A11 antisense (HOXA11-AS) in the tumorigenesis of non-small cell lung cancer (NSCLC).

METHODS

HOXA11-AS, microRNA-148a-3p (miR-148a-3p), and DNA methyltransferase 1 (DNMT1) mRNA levels were measured by RT-qPCR assay. DNMT1 protein level was determined by Western blot assay. Cell proliferative capacity and apoptotic rate were determined by CCK-8 assay and flow cytometry analysis, respectively. The relationships of HOXA11-AS, miR-148a-3p, and DNMT1 were tested through bioinformatics analysis, luciferase assay, and RNA pull down assay. Mouse xenograft models of NSCLC were established to examine the biological function of HOXA11-AS in vivo.

RESULTS

HOXA11-AS expression was notably upregulated and miR-148a-3p expression was conspicuously downregulated in NSCLC tissues and cells. HOXA11-AS knockdown curbed NSCLC cell proliferation and promoted cell apoptosis through directly increasing miR-148a-3p expression. Moreover, miR-148a-3p overexpression suppressed NSCLC cell proliferation and induced cell apoptosis. HOXA11-AS functioned as a competing endogenous RNA (ceRNA) of miR-148a-3p to increase DNMT1 expression in NSCLC cells. And, DNMT1 upregulation weakened the influence of HOXA11-AS1 loss on NSCLC cell proliferation and apoptosis. Additionally, HOXA11-AS knockdown suppressed NSCLC xenograft growth by upregulating miR-148a-3p and downregulating DNMT1 in vivo.

CONCLUSION

HOXA11-AS facilitated NSCLC tumorigenesis through miR-148a-3p/DNMT1 axis in vitro and in vivo, deepening our understanding of the molecular basis of HOXA11-AS in the development of NSCLC.

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.

Identification and validation of microRNAs and their targets expressed in osteosarcoma

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

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.

Extracellular vesicles from osteosarcoma cell lines contain miRNAs associated with cell adhesion and apoptosis

Osteosarcoma is the most common primary bone tumor during childhood and adolescence. Several reports have presented data on serum biomarkers for osteosarcoma, but few reports have analyzed circulating microRNAs (miRNAs). In this study, we used next generation miRNA sequencing to examine miRNAs isolated from microvesicle-depleted extracellular vesicles (EVs) derived from six different human osteosarcoma or osteoblastic cell lines with different degrees of metastatic potential (i.e., SAOS2, MG63, HOS, 143B, U2OS and hFOB1.19). EVs from each cell line contain on average ~300 miRNAs, and ~70 of these miRNAs are present at very high levels (i.e., >1000 reads per million). The most prominent miRNAs are miR-21-5p, miR-143-3p, miR-148a-3p and 181a-5p, which are enriched between 3 and 100 fold and relatively abundant in EVs derived from metastatic SAOS2 cells compared to non-metastatic MG63 cells. Gene ontology analysis of predicted targets reveals that miRNAs present in EVs may regulate the metastatic potential of osteosarcoma cell lines by potentially inhibiting a network of genes (e.g., MAPK1, NRAS, FRS2, PRCKE, BCL2 and QKI) involved in apoptosis and/or cell adhesion. Our data indicate that osteosarcoma cell lines may selectively package miRNAs as molecular cargo of EVs that could function as paracrine agents to modulate the tumor micro-environment.

Up-regulation of miRNA-148a inhibits proliferation, invasion, and migration while promoting apoptosis of cervical cancer cells by down-regulating RRS1

The purpose of the present study is to figure out the role of miRNA-148a (miR-148a) in growth, apoptosis, invasion, and migration of cervical cancer cells by binding to regulator of ribosome synthesis 1 (RRS1). Cervical cancer and adjacent normal tissues, as well as cervical cancer cell line Caski, HeLa, C-33A, and normal cervical epithelial cell line H8 were obtained to detect the expression of miR-148a and RRS1. Relationship between miR-148a and RRS1 expression with clinicopathological characteristics was assessed. The selected Caski and HeLa cells were then transfected with miR-148a mimics, miR-148a inhibitors or RRS1 siRNA to investigate the role of miR-148a and RRS1 on proliferation, apoptosis, colony formation, invasion, and migration abilities of cervical cancer cells. Bioinformatics information and dual luciferase reporter gene assay was for used to detect the targetting relationship between miR-148a and RRS1. Down-regulated miR-148a and up-regulated RRS1 were found in cervical cancer tissues and cells. Down-regulated miR-148a and up-regulated RRS1 are closely related with prognostic factors of cervical cancer. RRS1 was determined as a target gene of miR-148a and miR-148a inhibited RRS1 expression in cervical cancer cells. Up-regulation of miR-148a inhibited cell proliferation, migration, and invasion while promoting apoptosis in Caski and HeLa cells. Our study suggests that miR-148a down-regulates RRS1 expression, thereby inhibiting the proliferation, migration, and invasion while promoting cell apoptosis of cervical cancer cells.

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.

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.

Clinical Impact of Epithelial-to-Mesenchymal Transition Regulating MicroRNAs in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive carcinoma entities worldwide with early and rapid dissemination. Recently, we discussed the role of microRNAs as epigenetic regulators of Epithelial-to-Mesenchymal Transition (EMT) in PDAC. In this study, we investigated their value as diagnostic and prognostic markers in tissue and blood samples of 185 patients including PDAC, non-malignant pancreatic disorders, and age-matched healthy controls. Expression of the microRNA-200-family (microRNAs -141, -200a, -200b, -200c, -429) and microRNA-148a was significantly downregulated in tissue of PDAC Union internationale contre le cancer (UICC) Stage II. Correspondingly, stromal PDAC tissue showed strong expression of Fibronectin, Vimentin, and ZEB-1 (Zinc finger E-box-binding homeobox) versus low expression of E-cadherin. Transient transfection of microRNA-200b and microRNA-200c mimics resulted in the downregulation of their key target ZEB-1. Inversely, blood serum analyses of patients with PDAC UICC Stages II, III, and IV showed a significant over-expression of microRNA-200-family members, microRNA-148a, microRNA-10b, and microRNA-34a. Correspondingly, Enzyme-linked Immunosorbent Assay (ELISA) analyses revealed a significant over-expression of soluble E-cadherin in serum samples of PDAC patients versus healthy controls. The best diagnostic accuracy to distinguish between PDAC and non-PDAC in this patient collective could be achieved in tissue by microRNA-148a with an area under the receiver-operating-characteristic (ROC) curve (AUC) of 0.885 and in blood serum by a panel of microRNA-141, -200b, -200c, and CA.19-9 with an AUC of 0.890. Both diagnostic tools outreach the diagnostic performance of the currently most common diagnostic biomarker CA.19-9 (AUC of 0.834). Kaplan Meier survival analysis of this patient collective revealed an improved overall survival in PDAC patients with high expression of tissue-related microRNA-34a, -141, -200b, -200c, and -429. In conclusion, EMT-regulating microRNAs have great potential as liquid and solid biopsy markers in PDAC patients. Their prognostic and therapeutic benefits remain important tasks for future studies.

Increased levels of serum miR-148a-3p are associated with prostate cancer

Prostate cancer (PCa) is one of the most common types of cancer and the fifth leading cause of death among men worldwide. The tools for diagnosing PCa have limited value, and to improve correct diagnosis there is a need for markers that can contribute to a more precise diagnosis, which would lead to proper treatment of only those patients who need it. Micro RNA (miRNA) plays a key role in the development of cancer and is therefore a potential marker for PCa. Next-generation sequencing was used to discover differences in miRNA expression between serum samples from PCa patients and healthy controls, and the results were validated by quantitative real-time polymerase chain reaction. Detection of the miRNA of interest was attempted in prostate tissue by in situ hybridization. All samples were collected in collaboration with Biobank1^® . By miRNA sequencing of serum samples, significant expression of some miRNAs in patients with PCa and healthy controls was detected. This study showed that miR-148a-3p is upregulated in men with PCa, and the miRNA is differentially expressed in PCa patients compared to healthy controls. The results also showed that miR-148a-3p is located in prostate tissue.

Detection of circulating tumour DNA is associated with inferior outcomes in Ewing sarcoma and osteosarcoma: a report from the Children's Oncology Group

BACKGROUND

New prognostic markers are needed to identify patients with Ewing sarcoma (EWS) and osteosarcoma unlikely to benefit from standard therapy. We describe the incidence and association with outcome of circulating tumour DNA (ctDNA) using next-generation sequencing (NGS) assays.

METHODS

A NGS hybrid capture assay and an ultra-low-pass whole-genome sequencing assay were used to detect ctDNA in banked plasma from patients with EWS and osteosarcoma, respectively. Patients were coded as positive or negative for ctDNA and tested for association with clinical features and outcome.

RESULTS

The analytic cohort included 94 patients with EWS (82% from initial diagnosis) and 72 patients with primary localised osteosarcoma (100% from initial diagnosis). ctDNA was detectable in 53% and 57% of newly diagnosed patients with EWS and osteosarcoma, respectively. Among patients with newly diagnosed localised EWS, detectable ctDNA was associated with inferior 3-year event-free survival (48.6% vs. 82.1%; p = 0.006) and overall survival (79.8% vs. 92.6%; p = 0.01). In both EWS and osteosarcoma, risk of event and death increased with ctDNA levels.

CONCLUSIONS

NGS assays agnostic of primary tumour sequencing results detect ctDNA in half of the plasma samples from patients with newly diagnosed EWS and osteosarcoma. Detectable ctDNA is associated with inferior outcomes.

HOTAIRM1 competed endogenously with miR-148a to regulate DLGAP1 in head and neck tumor cells

This study is aimed to explore the regulatory effect of lncRNA HOTAIR/miR-148a/DLGAP1 axis on head and neck tumor (HNT) cell growth, cell mobility, and invasiveness. HOTAIRM1, miR-148a, and DLGAP1 level in HNT tissues and adjacent normal tissues were measured by qRT-PCR. Cell Counting Kit-8 (CCK-8) and Transwell (migration and invasion) assay were used to survey the influence of HOTAIRM1, miR-148a, and DLGAP1 on Fadu cells. Nude mouse xenograft was utilized to validate the influence of HOTAIRM1 in vivo. Dual-luciferase reporter assay confirms the relationship between HOTAIRM1 and miR-148a, miR-148a, and DLGAP1. The expression level of HOTAIRM1 was downregulated in human HNT tissues and cells. Overexpression of HOTAIRM1 significantly moderated Fadu cells proliferation, apoptosis, migration, and invasion in vitro and impaired the tumorigenesis in vivo. The expression level of miR-148a was upregulated in human HNT tissue compared to the adjacent tissues. We identified that miR-148a was a target of HOTAIRM1 and its expression levels were reduced by HOTAIRM1. Transfection of miR-148a mimics increased proliferation, migration, and invasion of Fadu cells. DLGAP1 was identified as a novel target of miR-148a and its expression level was promoted by either HOTAIRM1 overexpression or miR-148a knockdown. Overexpression of DLGAP1 also facilitated the cell viability and metastasis of Fadu cells. HOTAIRM1 was confirmed as a tumor suppressor via sponging miR-148a and promote the expression of DLGAP1, which could be regarded as an important target for the prevention and treatment of HNT.

miR-30a suppresses osteosarcoma proliferation and metastasis by downregulating MEF2D expression

Many studies have revealed that microRNAs (miRNAs) play crucial roles in cancer development and progression. miRNA-30a (miR-30a), as a member of the miR-30 family, has been implicated in various cancers. However, the role of miR-30a in osteosarcoma remains unclear. In the current study, we found that miR-30a was significantly downregulated in osteosarcoma tissues and cell lines by using quantitative real-time polymerase chain reaction (qRT-PCR). In addition, miR-30a could inhibit cancer cell growth, migration, and invasion in vitro. Furthermore, bioinformatics of miRNA target prediction and luciferase reporter assay indicated that MEF2D is a direct target of miR-30a. miR-30a was able to reduce the mRNA and protein expression of MEF2D as assessed using RT-PCR and Western blotting assay. Interestingly, overexpression of MEF2D partially reversed the miR-30a-reduced cell proliferation, migration, and invasion of osteosarcoma cell, indicating that miR-30a suppresses osteosarcoma cell proliferation and metastasis partially mediated by inhibition of MEF2D. Overall, our study demonstrated that miR-30a functions as a tumor suppressor by targeting MEF2D in osteosarcoma, providing a promising prognostic biomarker and a therapeutic strategy for osteosarcoma.

Role of microRNAs in progenitor cell commitment and osteogenic differentiation in health and disease (Review)

MicroRNAs (miRNAs) are considered 'micro- managers of gene expression' and awareness of their fundamental role in the control of biological functions is constantly increasing. Bone formation and homeostasis are complex processes involving the differentiation and interaction of various cell types. Several miRNAs have been shown to be involved in different pathways and stages in the regulation of normal and abnormal bone formation and turnover. This present review focuses on the involvement of miRNAs in terms of their effect on the commitment of bone marrow mesenchymal stem cells towards osteogenesis, adipogenesis and chondrogenesis, respectively. The miRNAs involved in regulating osteoblast, chondroblast and osteoclast activity, are also taken into consideration, as are their interactions. miRNA expression levels, which may differ significantly in healthy versus pathological conditions, can be readily monitored and represent useful biomarkers. Several studies have suggested that miRNAs offer potential as useful biomarkers of bone pathologies, including osteoporosis and osteosarcoma. The development of efficient methods of delivering miRNA mimics or miRNA inhibitors into specific cells remains a challenge for novel therapeutic applications in the field of personalized medicine.

The Potential Role of miRNAs as New Biomarkers for Osteoporosis

Osteoporosis is the most common metabolic bone disorder affecting up to 40% of postmenopausal women, characterized by a reduction in bone mass and strength leading to bone fragility and fractures. Despite the available tools for diagnosis and stratification of a fracture risk, bone loss occurs insidiously and osteoporosis is often diagnosed after the first fracture has occurred, with important health-related outcomes. Therefore, the need of markers that could efficiently diagnose bone fragility and osteoporosis is still necessary. Over the past few years, novel studies have focused on miRNAs, small noncoding RNAs that are differentially expressed in many pathological conditions, making them attractive biomarkers. To date, the role of miRNAs in bone disorders remains in great part unclear. In particular, limited and partly conflicting information is available concerning their use as potential biomarkers for osteoporosis, due to differences in patient selection, type of samples, and analytical methods. Despite these limits, concordant information about some specific miRNAs is now arising, making likely their use as additional tools to stratify the risk of osteoporosis and possibly fractures. In this review, we summarize the most relevant studies concerning circulating miRNAs differentially expressed in osteoporotic patients along with their function in bone cells and bone turnover.

Biomarker significance of plasma and tumor miR-21, miR-221, and miR-106a in osteosarcoma

Osteosarcoma is the most common malignant bone tumor in children and young adults. Despite the use of surgery and multi-agent chemotherapy, osteosarcoma patients who have a poor response to chemotherapy or develop relapses have a dismal outcome. Identification of biomarkers for active disease may help to monitor tumor burden, detect early relapses, and predict prognosis in these patients. In this study, we examined whether circulating miRNAs can be used as biomarkers in osteosarcoma patients. We performed genome-wide miRNA profiling on a discovery cohort of osteosarcoma and control plasma samples. A total of 56 miRNAs were upregulated and 164 miRNAs were downregulated in osteosarcoma samples when compared to control plasma samples. miR-21, miR-221 and miR-106a were selected for further validation based on their known biological importance. We showed that all three circulating miRNAs were expressed significantly higher in osteosarcoma samples than normal samples in an independent cohort obtained from the Children's Oncology Group. Furthermore, we demonstrated that miR-21 was expressed significantly higher in osteosarcoma tumors compared with normal bone controls. More importantly, lower expressions of miR-21 and miR-221, but not miR-106a, significantly correlated with a poor outcome. In conclusion, our results indicate that miR-21, miR-221 and miR-106a were elevated in the circulation of osteosarcoma patients, whereas tumor expressions of miR-21 and miR-221 are prognostically significant. Further investigation of these miRNAs may lead to a better prognostic method and potential miRNA therapeutics for osteosarcoma.

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

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

Circulating microRNAs and Bioinformatics Tools to Discover Novel Diagnostic Biomarkers of Pediatric Diseases

MicroRNAs (miRNAs) are small noncoding RNAs that regulate gene expression at the post-transcriptional level. Current studies have shown that miRNAs are also present in extracellular spaces, packaged into various membrane-bound vesicles, or associated with RNA-binding proteins. Circulating miRNAs are highly stable and can act as intercellular messengers to affect many physiological processes. MicroRNAs circulating in body fluids have generated strong interest in their potential use as clinical biomarkers. In fact, their remarkable stability and the relative ease of detection make circulating miRNAs ideal tools for rapid and non-invasive diagnosis. This review summarizes recent insights about the origin, functions and diagnostic potential of extracellular miRNAs by especially focusing on pediatric diseases in order to explore the feasibility of alternative sampling sources for the development of non-invasive pediatric diagnostics. We will also discuss specific bioinformatics tools and databases for circulating miRNAs focused on the identification and discovery of novel diagnostic biomarkers of pediatric diseases.

Evaluating the prognostic value of miR-148/152 family in cancers: based on a systemic review of observational studies

Background

The prognostic significance of MicroRNA-148/152 (miR-148/152) family expression in various cancers has been investigated by many studies with inconsistent results. To address this issue, we performed a meta-analysis to clarify this relationship.

Materials and Methods

Eligible studies were recruited by a systematic literature search and assessed the quality of included studies based on Quality In Prognosis Studies (QUIPS) and Newcastle-Ottawa Scale (NOS). Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) for overall survival (OS) and disease free survival/progressive free survival/recurrence free survival (DFS/PFS/RFS) were calculated to estimate the effects of miR-148/152 family expression on prognosis.

Results

A final total of 23 articles (26 studies) were considered in evidence synthesis. A significant association was observed between low miR-148a level and poor OS in patients (HR = 1.59, 95% CI: 1.14 – 2.20, P = 0.00), especially with digestive tract cancer (DTC) (HR = 1.29, 95% CI: 1.03–1.63, P = 0.03), and another significant association was observed between low miR-148b level and poor OS in patients (HR=2.09, 95% CI: 1.70–2.56, P = 0.00), especially with (hepatocellular carcinoma) HCC (HR = 1.97, 95% Cl: 1.52–2.56, P = 0.00) and non-small cell lung cancer (NSCLC) (HR = 2.29, 95% Cl: 1.64–3.18, P = 0.00). The significant correlation between miR-152 and DFS/RFS was found in our research (HR = 3.49, 95% Cl: 1.13–10.08, P = 0.03).

Conclusions

Our findings suggest that low miR-148/152 family expression is significantly associated with poor prognosis and may be a feasible prognostic biomarker in some cancers, especially in HCC and NSCLC.

Mesenchymal stroma: Role in osteosarcoma progression

The initiation and progression of malignant tumors are supported by their microenvironment: cancer cells per se cannot explain growth and formation of the primary or metastasis, and a combination of proliferating tumor cells, cancer stem cells, immune cells mesenchymal stromal cells and/or cancer-associated fibroblasts all contribute to the tumor bulk. The interaction between these multiple players, under different microenvironmental conditions of biochemical and physical stimuli (i.e. oxygen tension, pH, matrix mechanics), regulates the production and biological activity of several soluble factors, extracellular matrix components, and extracellular vesicles that are needed for growth, maintenance, chemoresistance and metastatization of cancer. In osteosarcoma, a very aggressive cancer of young adults characterized by the extensive need for more effective therapies, this aspect has been only recently explored. In this view, we will discuss the role of stroma, with a particular focus on the mesenchymal stroma, contributing to osteosarcoma progression through inherent features for homing, neovascularization, paracrine cross-feeding, microvesicle secretion, and immune modulation, and also by responding to the changes of the microenvironment that are induced by tumor cells. The most recent advances in the molecular cues triggered by cytokines, soluble factors, and metabolites that are partially beginning to unravel the axis between stromal elements of mesenchymal origin and osteosarcoma cells, will be reviewed providing insights likely to be used for novel therapeutic approaches against sarcomas.

MicroRNAs with prognostic significance in osteosarcoma: a systemic review and meta-analysis

Introduction

This study aimed to elucidate the prognostic value of microRNAs (miRNAs) in patients with osteosarcoma.

Materials and Methods

Studies were recruited by searching PubMed, Embase, the Cochrane Library, China National Knowledge Infrastructure, and Wanfang data-bases (final search update conducted January 2017). Eligible studies were identified and the quality was assessed using multiple search strategies.

Results

A total of 55 articles that investigated the correlation between miRNA expression and either patient survival or disease recurrence in osteosarcoma was initially identified. Among these, 30 studies were included in the meta-analysis. The results of our meta-analysis revealed that elevated levels of miR-21, miR-214, miR-29, miR-9 and miR-148a were associated with poor prognosis in osteosarcoma. Additionally, downregulated miR-382, miR26a, miR-126, miR-195 and miR-124 expression indicated poor prognosis in osteosarcoma.

Conclusions

miRNAs may act as independent prognostic factors in patients with osteosarcoma and are useful in stratifying risk.

Exosomes containing differential expression of microRNA and mRNA in osteosarcoma that can predict response to chemotherapy

A major challenge in osteosarcoma (OS) is the selection of the most effective chemotherapeutic agents for individual patients, while the administration of ineffective chemotherapy increases mortality and decreases quality of life in patients. This emphasizes the need to evaluate every patient's probability of responding to each chemotherapeutic agent. We developed a profiling strategy for serum exosomal microRNAs and mRNAs in OS patients with differential chemotherapeutic responses. Twelve miRNAs were up regulated and 18 miRNAs were under regulated significantly in OS patient with poor chemotherapeutic response when compared with those in good chemotherapeutic response (p<0.05). In addition, miR-124, miR133a, miR-199a-3p, and miR-385 were validated and significantly reduced in poorly responded patients with an independent OS cohort. While miR-135b, miR-148a, miR-27a, and miR-9 were significantly over expressed in serum exosomes. Bioinformatic analysis by DIANA-mirPath demonstrated that Proteoglycans in cancer, Hippo signaling pathway, Pathways in cancer, Transcriptional misregulation in cancer, PI3K-Akt signaling pathway, Ras signaling pathway, Ubiquitin mediated proteolysis, Choline metabolism in cancer were the most prominent pathways enriched in quantiles with the miRNA patterns related to poor chemotherapeutic response. Messenger RNAs(mRNAs) includingAnnexin2, Smad2, Methylthioadenosine phosphorylase (MTAP), Cdc42-interacting protein 4 (CIP4), Pigment Epithelium-Derived Factor (PEDF), WW domain-containing oxidoreductase (WWOX), Cell division cycle 5-like (Cdc5L), P27 were differentially expressed in exosomes in OS patients with different chemotherapeutic response. These data demonstrated that exosomal RNA molecules are reliable biomarkers in classifying osteosarcoma with different chemotherapy sensitivity.

A liquid biopsy-based method for the detection and quantification of circulating tumor cells in surgical osteosarcoma patients

A method for the enumeration and quantification of osteosarcoma (OS) circulating tumor cells (CTCs) is currently not available. A correlation between the number of CTCs and progression-free survival (PFS) has been established for other cancers, but not for OS CTCs. A method was therefore developed for CTC quantification in OS and validated in a prospective cohort of surgical patients with primary and recurrent/metastatic OS (N=23). Human OS cells, acting as CTCs, were enumerated from spiked human peripheral blood (PB) following erythrocyte and leukocyte depletion. The OS cells were quantified microscopically based on aneuploidy and a CK18-/CD45- phenotype. Aneuploidy was assayed by fluorescence in situ hybridization (FISH) using fluorescence-labeled alpha-satellite probes for the centromeres of chromosome (CEP 8). CK18 and CD45 phenotyping was performed with immunocytochemistry. HOS cells in spiked PB could be effectively retrieved with the FISH-based enumeration method, which was subsequently employed in an OS patient cohort. PB of recurrent/metastatic OS patients contained more CTCs than the PB of primary OS patients. OS patients with ≥2 CTCs per 7.5 ml of PB had worse PFS than patients whose PB contained <2 CTCs. In 2 cases, CTCs were present in PB of OS patients with negative X-ray and chest CT scans. In conclusion, our method was able to quantitate CTCs in liquid biopsies of OS patients. The number of CTCs has diagnostic and prognostic value.

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

Background

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

Material/Methods

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

Results

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

Conclusions

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

miR-24 represses metastasis of human osteosarcoma cells by targeting Ack1 via AKT/MMPs pathway

The expression levels of the protein tyrosine kinase Ack1 has been reported to be dysregulated in various cancers and involve in oncogenesis and progression. However, the expression and role of Ack1 in osteosarcoma remains unknown. In this study, we found that Ack1 were evidently upregulated in human osteosarcoma tissues and cell lines. In addition, the clinical data showed that high expression level of Ack1 is closely associated with clinical stage and positive distant metastasis, and negatively correlated with overall survival. Then, bioinformatics prediction and luciferase reporter assay indicated Ack1 as a direct target of miR-24, and Ack1 could be downregulated by miR-24 at both the mRNA and protein expression levels. Moreover, Ack1 expression levels were inversely correlated with that of miR-24 in osteosarcoma tissues. Furthermore, functional assay showed that miR-24 significantly suppressed osteosarcoma progression partially mediated by inhibiting Ack1 expression. Finally, western bolt assay revealed that miR-24 regulate AKT/MMPs pathway via Ack1 in osteosarcoma cells. In conclusion, our study demonstrated the suppression of miR-24 on osteosarcoma metastasis by targeting Ack1 via AKT/MMPs pathways, providing a novel strategy for the diagnosis and treatment of osteosarcoma patients.

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

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