Noncoding RNAs as circulating biomarkers in osteosarcoma patients

Intelligent structure prediction and visualization analysis of non-coding RNA in osteosarcoma research

Background

Osteosarcoma (OS) is the most common bone malignant tumor in children and adolescents. Recent research indicates that non-coding RNAs (ncRNAs) have been associated with OS occurrence and development, with significant progress made in this field. However, there is no intelligent structure prediction and literature visualization analysis in this research field. From the perspective of intelligent knowledge structure construction and bibliometrics, this study will comprehensively review the role of countries, institutions, journals, authors, literature citation relationships and subject keywords in the field of ncRNAs in OS. Based on this analysis, we will systematically analyze the characteristics of the knowledge structure of ncRNAs in OS disease research and identify the current research hotspots and trends.

Methods

The Web of Science Core Collection (WoSCC) database was searched for articles on ncRNAs in OS between 2001 and 2023. This bibliometric analysis was performed using VOSviewers, CiteSpace, and Pajek.

Results

This study involved 15,631 authors from 2,631 institutions across 57 countries/regions, with a total of 3,642 papers published in 553 academic journals. China has the highest number of published papers in this research field. The main research institutions include Nanjing Medical University (n = 129, 3.54%), Shanghai Jiao Tong University (n = 128, 3.51%), Zhengzhou University (n = 110, 3.02%), and China Medical University (n = 109, 2.99%). Oncology Letters (n =139, 3.82%), European Review for Medical Pharmacological Sciences (120, 3.31%), and Molecular Medicine Reports (n = 95, 2.61%) are the most popular journals in this field, with Oncotarget being the most co-cited journal (Co-Citation = 4,268). Wei Wang, Wei Liu, and Zhenfeng Duan published the most papers, with Wang Y being the most co-cited author. "miRNA", "lncRNA" and "circRNA" are the main focuses of ncRNAs in OS studies. Key themes include "migration and invasion", "apoptosis and proliferation", "prognosis", "biomarkers" and "chemoresistance". Since 2020, hotspots and trends in ncRNA research in OS include "tumor microenvironment", "immune" and "exosome".

Conclusion

This study represents the first comprehensive bibliometric analysis of the knowledge structure and development of ncRNAs in OS. These findings highlight current research hotspots and frontier directions, offering valuable insights for future studies on the role of ncRNAs in OS.

Knockdown of LncRNA DICER1-AS1 arrests the cell cycle, inhibits cell proliferation, and induces cell apoptosis by regulating CDC5L nuclear transfer in osteosarcoma

BACKGROUND

DICER1-AS1 is reported to promote the progression and disturb the cell cycle in osteosarcoma; however, its mechanism has rarely been studied.

MATERIALS AND METHODS

DICER1-AS1 expression levels were evaluated by qPCR and fluorescence in situ hybridization (FISH). The total, nuclear, and cytosolic levels of CDC5L were measured by western blotting and immunofluorescence (IF). Cell proliferation, apoptosis, and cell cycle analyses were conducted using the colony formation, CCK-8 assay, terminal transferase-mediated UTP nick end-labeling kit (TUNEL) assay, and flow cytometry. Levels of cell proliferation-, cell cycle-, and cell apoptosis-related proteins were determined by western blotting. RNA immunoprecipitation (RIP) and RNA pull-down assays were conducted to evaluate the relationship between DICER1-AS1 and CDC5L.

RESULTS

LncRNA DICER1-AS1 was highly expressed in samples of osteosarcoma tissue and in osteosarcoma cell lines. DICER1-AS1 knockdown inhibited cell proliferation, promoted cell apoptosis, and disturbed the cell cycle. Moreover, DICER1-AS1 was found to bind with CDC5L, and knockdown of DICER-AS1 inhibited the nuclear transfer of CDC5L. DICER1-AS1 knockdown also reversed the effects of CDC5L overexpression on cell proliferation, apoptosis, and the cell cycle. Moreover, CDC5L inhibition suppressed cell proliferation, promoted cell apoptosis, and disturbed the cell cycle, and those effects were further enhanced by DICER1-AS1 knockdown. Finally, DICER1-AS knockdown inhibited tumor growth and proliferation, and promoted cell apoptosis in vivo.

CONCLUSION

LncRNA DICER1-AS1 knockdown inhibits the nuclear transfer of CDC5L protein, arrests the cell cycle, and induces apoptosis to suppress the development of osteosarcoma. Our results suggest a novel target (DICER1-AS1) for treatment of osteosarcoma.

MiR-4270 acts as a tumor suppressor by directly targeting Bcl-xL in human osteosarcoma cells

Chondrosarcomas and osteosarcomas are malignant bone tumors with a poor prognosis when unresectable or metastasized. Moreover, radiotherapy and chemotherapy could be ineffective. MiRNAs represent an alternative therapeutic approach. Based on high-throughput functional screening, we identified four miRNAs with a potential antiproliferative effect on SW1353 chondrosarcoma cells. Individual functional validations were then performed in SW1353 cells, as well as in three osteosarcoma cell lines. The antiproliferative and cytotoxic effects of miRNAs were evaluated in comparison with a positive control, miR-342-5p. The cytotoxic effect of four selected miRNAs was not confirmed on SW1353 cells, but we unambiguously revealed that miR-4270 had a potent cytotoxic effect on HOS and MG-63 osteosarcoma cell lines, but not on SaOS-2 cell line. Furthermore, like miR-342-5p, miR-4270 induced apoptosis in these two cell lines. In addition, we provided the first report of Bcl-xL as a direct target of miR-4270. MiR-4270 also decreased the expression of the anti-apoptotic protein Mcl-1, and increased the expression of the pro-apoptotic protein Bak. Our findings demonstrated that miR-4270 has tumor suppressive activity in osteosarcoma cells, particularly through Bcl-xL downregulation.

miRNA, lncRNA and circRNA: targeted molecules with therapeutic promises in Mycoplasma pneumoniae infection

Mycoplasma pneumoniae (MP) is primarily recognized as a respiratory pathogen that causes community-acquired pneumonia, which can lead to acute upper and lower airway inflammation and extrapulmonary syndrome. Refractory pneumonia caused by MP can cause severe complications and even be life-threatening, particularly in infants and the elderly. It is well-known that non-coding RNAs (ncRNAs) represented by miRNAs, lncRNAs and circRNAs have been manifested to be widely involved in the regulation of gene expression. Growing evidence indicates that these ncRNAs have distinct differentiated expression in MP infection and affect multiple biological processes, playing an indispensable role in the initiation and promotion of MP infection. However, the epigenetic mechanisms involved in the development of MP infection remain unclear. This article reviews the mechanisms by which miRNAs, lncRNAs, and circRNAs mediate MP infection, such as inflammatory responses, apoptosis and pulmonary fibrosis. Focusing on miRNAs, lncRNAs and circRNAs associated with MP infection could provide new insights into this disease's early diagnosis and therapeutic approaches.

CDKN2B-AS1 as a novel therapeutic target in cancer: Mechanism and clinical perspective

Long non-coding RNAs (lncRNA) have been identified as essential components having considerable modulatory impactson biological activities through altering gene transcription, epigenetic changes, and protein translation. Cyclin-dependent kinase inhibitor 2B antisense RNA 1 (CDKN2B-AS1), a recently discovered lncRNA, was shown to be substantially elevated in various cancers.Furthermore, via modulation ofvarious signalingaxes, it is effectively connected to the control of critical cancer-associatedbiological pathways likecell proliferation, apoptosis, cell cycle, epithelial-mesenchymal transition(EMT), invasion, and migration. Considering the crucial functions ofCDKN2B-AS1in cancer onset and development, this lncRNA offers immense therapeutic implications for usage as a new diagnostic or treatment approach. In this article, we evaluate the most recent discoveries made into the functions of the lncRNA CDKN2B-AS1 in cancer, in addition to its prospect asbeneficial properties,prognostic anddiagnostic biomarkersin the cancer-related treatment, emphasizingits participation in a broad network of signalingaxes whichcould affectvariouscancers and investigating its promising therapeutic possibility.

Gallic acid mediates tumor-suppressive effects on osteosarcoma through the H19-Wnt/β-catenin regulatory axis

Background

Osteosarcoma (OS) is the most common primary malignancy in bone tissues, and effective therapeutics remain absent in clinical practice. Traditional Chinese medicines (TCM) have been used for thousands of years, which provide great insights into OS management. Gallic acid (GA) is a natural phenolic acid enriched in various foods and herbs. Several pharmacological activities of GA such as anti-oxidation and anti-inflammation have been well-established. However, its biological function in OS remains not fully understood.

Methods

The potential anti-cancer properties of GA were evaluated in 143 ​B, U2OS and MG63 ​cells. Its effects on cell growth, cell cycle, apoptosis and migration were examined in these OS cells. The lncRNA H19 and Wnt/β-catenin signaling were detected by qPCR, luciferase activity and Western blotting assays. The in vivo effect of GA on tumor growth was investigated using an orthotopic mouse model.

Results

In the present study, GA was found to suppress the tumor growth in vitro via inducing cell cycle arrest and apoptosis in OS cells, and inhibit the invasion and metastasis as well. Using the orthotopic animal model, GA was also found to suppress tumorigenesis in vivo. Long noncoding RNA (lncRNA) H19 was demonstrated to be down-regulated by GA, and thus disrupted the canonical Wnt/β-catenin signaling in OS cells. Furthermore, the ectopic expression of H19 rescued the GA-induced suppressive effects on tumor growth and metastasis, and partially reversed the inactivation of Wnt/β-catenin signaling.

Conclusions

Taken together, our results indicated that GA inhibited tumor growth through an H19-mediated Wnt/β-catenin signaling regulatory axis in OS cells.

The translational potential of this article

The information gained from this study provides a novel underlying mechanism of GA mediated anti-OS activity, suggesting that GA may be a promising drug candidate for OS patients.

Bioinformatics analysis of lncRNAs in the occurrence and development of osteosarcoma

BACKGROUND

Osteosarcoma (OS) is a disease with high mortality in children and adolescents, and metastasis is one of its important clinical features. However, the molecular mechanism of OS occurrence is not completely clear. Thus, we screened potential biomarkers of OS and analyze their prognostic value.

METHODS

The Cancer Genome Atlas (TCGA) datasets were used to analyze the differential lncRNAs in patients with OS of different immune score and the lncRNAs expressed by immune cells. Cox regression was used to develop the prognosis prediction model and specify the prognosis outcomes. Risk-proportional regression model was constructed, and the samples were divided into high and low groups based on the risk scores for the survival analysis. The areas under the receiver operating characteristic (ROC) curve were calculated and the risk-score model was verified. Finally, using 4 gene sets (comprising chemokines, immune checkpoint blockades, immune activity-related genes, and immune cells), and 4 analysis tools (CIBERSORT, TIMER, XCELL and MCP) to evaluated tumor immune infiltration.

RESULTS

Twenty-nine long non-coding ribonucleic acids (lncRNAs) were obtained from the intersection of the screened lncRNAs. Caspase recruitment domain-containing protein 8-antisense RNA 1 (CARD8-AS1), lncRNA five prime to Xist (FTX), KAT8 regulatory NSL complex unit 1-antisense RNA 1 (KANSL1-AS1), Neuroplastin Intronic Transcript 1 (NPTN-IT1), oligodendrocyte maturation-associated long intervening non-coding RNA (OLMALINC) and RPARP Antisense RNA 1 (RPARP-AS1) were found to be correlated with survival. Univariate and multivariate regression analysis showed risk score [HR (hazard ratio) 3.5, P value 0.0043; HR 3.7, P value 0.0033] and metastasis (HR 4.7, P value 6.60E-05; HR 4.8, P value 8.36E-05) were the key factors of patients with OS. The areas under curves (AUCs) of the 1-, 3-, and 5-year ROC curves of the prognostic model were 0.715, 0.729, and 0.771. The low-risk patients tended to have a high abundance of immune cells.

CONCLUSIONS

This study showed that a risk score based on 6 lncRNAs has potential value in the prognosis of OS, and patients with low-risk scores have high immune cell infiltration and good prognosis. This study may enrich understandings of underlying mechanisms related to the occurrence and development of OS.

Navigating the genomic instability mine field of osteosarcoma to better understand implications of non-coding RNAs

Osteosarcoma is one of the most genomically complex cancers and as result, it has been difficult to assign genomic aberrations that contribute to disease progression and patient outcome consistently across samples. One potential source for correlating osteosarcoma and genomic biomarkers is within the non-coding regions of RNA that are differentially expressed. However, it is unsurprising that a cancer classification that is fraught with genomic instability is likely to have numerous studies correlating non-coding RNA expression and function have been published on the subject. This review undertakes the formidable task of evaluating the published literature of noncoding RNAs in osteosarcoma. This is not the first review on this topic and will certainly not be the last. The review is organized with an introduction into osteosarcoma and the epigenetic control of gene expression before reviewing the molecular function and expression of long non-coding RNAs, circular RNAs, and short non-coding RNAs such as microRNAs, piwi RNAs, and short-interfering RNAs. The review concludes with a review of the literature and how the biology of non-coding RNAs can be used therapeutically to treat cancers, especially osteosarcoma. We conclude that non-coding RNA expression and function in osteosarcoma is equally complex to understanding the expression differences and function of coding RNA and proteins; however, with the added lens of both coding and non-coding genomic sequence, researchers can begin to identify the patterns that consistently associate with aggressive osteosarcoma.

Tumor Suppressive Role of miR-342-5p and miR-491-5p in Human Osteosarcoma Cells

Osteosarcomas are the most common type of malignant bone tumor. These tumors are characterized by the synthesis of an osteoid matrix. Current treatments are based on surgery and combination chemotherapy. However, for metastatic or recurrent tumors, chemotherapy is generally ineffective, and osteosarcomas are sometimes unresectable. Thus, the use of microRNAs (miRNAs) may represent an attractive alternative for the development of new therapies. Using high-throughput functional screening based on impedancemetry, we previously selected five miRNAs with potential chemosensitizing or antiproliferative effects on chondrosarcoma cells. We validated the tumor-suppressive activity of miR-491-5p and miR-342-5p in three chondrosarcoma cell lines. Here, we carried out individual functional validation of these five miRNAs in three osteosarcoma cell lines used as controls to evaluate their specificity of action on another type of bone sarcoma. The cytotoxic effects of miR-491-5p and miR-342-5p were also confirmed in osteosarcoma cells. Both miRNAs induced apoptosis. They increased Bcl-2 homologous antagonist killer (Bak) protein expression and directly targeted Bcl-2 lymphoma-extra large (Bcl-xL). MiR-342-5p also decreased B-cell lymphoma-2 (Bcl-2) protein expression, and miR-491-5p decreased that of Epidermal Growth Factor Receptor (EGFR). MiR-342-5p and miR-491-5p show tumor-suppressive activity in osteosarcomas. This study also confirms the potential of Bcl-xL as a therapeutic target in osteosarcomas.

Metastatic Progression of Osteosarcomas: A Review of Current Knowledge of Environmental versus Oncogenic Drivers

Simple Summary

Osteosarcomas are heterogeneous bone tumors with complex genetic and chromosomic alterations. The numerous patients with metastatic osteosarcoma have a very poor prognosis, and only those who can have full surgical resection of the primary tumor and of all the macro metastasis can survive. Despite the recent improvements in prediction and early detection of metastasis, big efforts are still required to understand the specific mechanisms of osteosarcoma metastatic progression, in order to reveal novel therapeutic targets.

Abstract

Metastases of osteosarcomas are heterogeneous. They may grow simultaneously with the primary tumor, during treatment or shortly after, or a long time after the end of the treatment. They occur mainly in lungs but also in bone and various soft tissues. They can have the same histology as the primary tumor or show a shift towards a different differentiation path. However, the metastatic capacities of osteosarcoma cells can be predicted by gene and microRNA signatures. Despite the identification of numerous metastasis-promoting/predicting factors, there is no efficient therapeutic strategy to reduce the number of patients developing a metastatic disease or to cure these metastatic patients, except surgery. Indeed, these patients are generally resistant to the classical chemo- and to immuno-therapy. Hence, the knowledge of specific mechanisms should be extended to reveal novel therapeutic approaches. Recent studies that used DNA and RNA sequencing technologies highlighted complex relations between primary and secondary tumors. The reported results also supported a hierarchical organization of the tumor cell clones, suggesting that cancer stem cells are involved. Because of their chemoresistance, their plasticity, and their ability to modulate the immune environment, the osteosarcoma stem cells could be important players in the metastatic process.

Knowledge atlas and emerging trends on ncRNAs of osteosarcoma: A bibliometric analysis

BACKGROUND

Osteosarcoma is a common bone sarcoma that occurs in childhood and adolescence. Although research on non-coding RNAs (ncRNAs) of osteosarcoma has been developed rapidly in recent years, a specific bibliometric analysis on this topic has not yet been performed. The bibliometric analysis aims to summarize knowledge atlas, research hotspots, and emerging trends and to provide researchers with new perspectives in further studies.

METHODS

All publications regarding ncRNAs of osteosarcoma published from 2000 to 2021 were retrieved from the Web of Science Core Collection. Quantitative indicators including the number of publications and citations, H-index, and journal citation reports were analyzed by using Excel 2019 and R software. VOSviewer and CiteSpace were used to analyze the cooperation among countries/institutions/journals/authors and the co-occurrence of keywords, keywords bursts, and references.

RESULTS

A total of 3206 publications were extracted. A significant growth trend in the annual number of publications over the past 22 years is revealed (R ² = 0.999). The most prolific country and institution were China (2260) and Shanghai Jiao Tong University (134), respectively. Professors Wang W and Liu W contributed the most to this field. The keywords were stratified into six clusters: Cluster 1 (apoptosis and growth), Cluster 2 (cancer and progression), Cluster 3 (microRNAs and downregulation), Cluster 4 (genes and differentiation), Cluster 5 (expression and biological functions), and Cluster 6 (metastasis). The long non-coding RNAs and circular RNAs have been considered as an important research hotspot in the near future.

CONCLUSION

This study offers a scientific perspective on ncRNAs of osteosarcoma and provides researchers with valuable information to understand the knowledge structure and to identify emerging trends in this field.

Overexpression of Long Non-Coding RNA MIR22HG Represses Proliferation and Enhances Apoptosis via miR-629-5p/TET3 Axis in Osteosarcoma Cells

In this study, we evaluated the mechanism of long non-coding RNA MIR22 host gene (LncRNA MIR22HG) in osteosarcoma cells. Forty-eight paired osteosarcoma and adjacent tissues samples were collected and the bioinformatic analyses were performed. Target genes and potential binding sites of MIR22HG, microRNA (miR)-629-5p and tet methylcytosine dioxygenase 3 (TET3) were predicted by Starbase and TargetScan V7.2 and confirmed by dual-luciferase reporter assay. Cell Counting Kit-8, colony formation and flow cytometry assays were utilized to determine the viability, proliferation and apoptosis of transfected osteosarcoma cells. Pearson's analysis was introduced for the correlation analysis between MIR22HG and miR-629-5p in osteosarcoma tissue. Relative expressions of MIR22HG, miR-629-5p and TET3 were measured by quantitative real-time polymerase chain reaction or Western blot. MiR-629-5p could competitively bind with and was negatively correlated with MIR22HG, the latter of which was evidenced by the high expression of miR-629-5p and low expression of MIR22HG in osteosarcoma tissues. Overexpressed MIR22HG repressed the viability and proliferation but enhanced apoptosis of osteosarcoma cells, which was reversed by miR-629-5p upregulation. TET3 was the target gene of miR-629-5p, and the promotive effects of upregulated miR-629-5p on the viability and proliferation as well as its repressive effect on apoptosis were abrogated via overexpressed TET3. To sum up, overexpressed MIR22HG inhibits the viability and proliferation of osteosarcoma cells, which was achieved via regulation of the miR-629-5p/TET3 axis.

LncRNA MATN1-AS1 for Prediction of Prognosis in Osteosarcoma Patients and Its Cellular Function

Long non-coding RNAs show essential roles in various cancer processes. This study aimed at the expression features, prognosis significance, and biological effect of lnc MATN1-AS1 in osteosarcoma (OS). Five kinds of cell lines and 117 pairs of tissues were analyzed by qRT-PCR for quantification of lnc MATN1-AS1 and miR-1299 level. Clinical data were analyzed using Chi-Square Tests to show the association with lnc MATN1-AS1 level. Kaplan-Meier analysis and Cox regression were used to judge the prognostic value. Cell counting kit-8 and Transwell assay were conducted, respectively, to analyze the effect of lnc MATN1-AS1 on cell proliferation and metastasis. The target miRNA was predicted. lnc MATN1-AS1 level was significantly elevated in OS cells and tissues and related to Enneking staging, lung metastasis, and histologic type. Patients with high lnc MATN1-AS1 level showed a shorter overall survival and recurrence-free survival. Lnc MATN1-AS1 knockdown inhibited OS cell proliferation, migration, and invasion by sponging miR-1299. Lnc MATN1-AS1 has oncogenic features and prognostic significance in OS and is a novel therapeutic strategy for OS.

MiRNAs and Cancer: Key Link in Diagnosis and Therapy

Since the discovery of the first microRNA (miRNA), the exploration of miRNA biology has come to a new era in recent decades. Monumental studies have proven that miRNAs can be dysregulated in different types of cancers and the roles of miRNAs turn out to function to either tumor promoters or tumor suppressors. The interplay between miRNAs and the development of cancers has grabbed attention of miRNAs as novel tools and targets for therapeutic attempts. Moreover, the development of miRNA delivery system accelerates miRNA preclinical implications. In this review, we depict recent advances of miRNAs in cancer and discuss the potential diagnostic or therapeutic approaches of miRNAs.

Circulating Long Non-Coding RNAs as Novel Potential Biomarkers for Osteogenic Sarcoma

Circulating cell-free nucleic acids recently became attractive targets to develop non-invasive diagnostic tools for cancer detection. Along with DNA and mRNAs, transcripts lacking coding potential (non-coding RNAs, ncRNAs) directly involved in the process of tumor pathogenesis have been recently detected in liquid biopsies. Interestingly, circulating ncRNAs exhibit specific expression patterns associated with cancer and suggest their role as novel biomarkers. However, the potential of circulating long ncRNAs (c-lncRNAs) to be markers in osteosarcoma (OS) is still elusive. In this study we performed a systematic review to identify thirteen c-lncRNAs whose altered expression in blood associate with OS. We herein discuss the potential impact that these c-lncRNAs may have on clinical decision-making in the management of OS. Overall, we aimed to provide novel insights that can contribute to the development of future precision medicine in oncology.

LncRNA LOC100129620 promotes osteosarcoma progression through regulating CDK6 expression, tumor angiogenesis, and macrophage polarization

Osteosarcoma is a malignant tumor with high mortality in children and adolescents. The mechanism of osteosarcoma metastasis is currently unclear. Abnormal expression of long non-coding RNA (lncRNA) plays an important role in tumor metastasis. We used bioinformatics to analyze the differences in gene expression between osteosarcoma in situ and osteosarcoma lung metastases. CCK-8 was used to detect the effect of lncRNA LOC100129620 on the proliferation of osteosarcoma cells. The effect of LOC100129620 on the invasion of osteosarcoma cells was assessed by Transwell assay. The regulatory effect of LOC100129620 on miR-335-3p was examined using RNA pull-down and luciferase reporter gene assays. The effect of LOC100129620 on the polarization of macrophages was detected by quantitative real-time fluorescent PCR. The results show that LOC100129620 can promote the proliferation and migration of osteosarcoma cells. LOC100129620 can promote the proliferation of osteosarcoma in vivo. LOC100129620 can bind to miR-335-3p and regulate its function. MiR-335-3p mediates the regulatory effects of LOC100129620 on CDK6. LOC100129620 promotes the formation of blood vessels and the polarization of macrophages. The LOC100129620/miR-335-3p/CDK6 signaling pathway promotes the metastasis of osteosarcoma by regulating the proliferation of osteosarcoma cells, angiogenesis, and macrophage polarization.

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

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

The value of lncRNAs as prognostic biomarkers on clinical outcomes in osteosarcoma: a meta-analysis

Background

In recent years, emerging studies have demonstrated critical functions and potential clinical applications of long non-coding RNA (lncRNA) in osteosarcoma. To further validate the prognostic value of multiple lncRNAs, we have conducted this updated meta-analysis.

Methods

Literature retrieval was conducted by searching PubMed, Web of Science and the Cochrane Library (last update by October 2, 2019). A meta-analysis was performed to explore association between lncRNAs expression and overall survival (OS) of osteosarcoma patients. Relationships between lncRNAs expression and other clinicopathological features were also analyzed respectively.

Results

Overall, 4351 patients from 62 studies were included in this meta-analysis and 25 lncRNAs were identified. Pooled analyses showed that high expression of 14 lncRNAs connoted worse OS, while two lncRNAs were associated with positive outcome. Further, analysis toward osteosarcoma clinicopathologic features demonstrated that overexpression of TUG1 and XIST indicated poor clinical parameters of patients.

Conclusions

This meta-analysis has elucidated the prognostic potential of 16 lncRNAs in human osteosarcoma. Evidently, desperate expression and functional targets of these lncRNAs offer new approaches for prognosis and therapy of osteosarcoma.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-07882-w.

Downregulation of long non-coding RNA UCA1 represses tumorigenesis and metastasis of osteosarcoma via miR-513b-5p/E2F5 axis

Long non-coding RNAs have the regulatory roles in different kinds of human cancers. The key point of this study was to research the functional mechanisms of urothelial carcinoma associated 1 (UCA1) in the development of osteosarcoma. Quantitative real-time PCR was adopted for the expression detection of UCA1, microRNA-513b-5p (miR-513b-5p) and E2F transcription factor 5 (E2F5). The target relation was verified via dual-luciferase reporter assay and RNA pull-down assay. Cell proliferation was evaluated using Cell Counting Kit-8 and colony formation assays. Transwell assay was applied to assess cell migration and invasion. Western blot was performed for protein examination. Xenograft experiment was used to explore the effect of UCA1 on osteosarcoma in vivo. UCA1 expression was enhanced while miR-513b-5p was refrained in osteosarcoma tissues and cells. MiR-513b-5p was a target of UCA1. Inhibition of UCA1 or overexpression of miR-513b-5p suppressed osteosarcoma cell proliferation, migration and invasion. E2F5 was identified as a downstream gene of miR-513b-5p. MiR-513b-5p inhibitor or E2F5 overexpression rescued the progression inhibition of osteosarcoma by UCA1 knockdown, and UCA1 regulated E2F5 and Cyclin E expression by targeting miR-513b-5p. Downregulation of UCA1 restrained the tumorigenesis of osteosarcoma in vivo through the miR-513b-5p/E2F5 axis. Collectively, knockdown of UCA1 inhibited tumorigenesis and metastasis of osteosarcoma via regulating the miR-513b-5p/E2F5 axis. UCA1 might be a biological indicator in the progression and treatment of osteosarcoma.

Recent Insights into Therapy Resistance in Osteosarcoma

Osteosarcoma, the most common bone malignancy of childhood, has been a challenge to treat and cure. Standard chemotherapy regimens work well for many patients, but there remain minimal options for patients with progressive or resistant disease, as clinical trials over recent decades have failed to significantly improve survival. A better understanding of therapy resistance is necessary to improve current treatments and design new strategies for future treatment options. In this review, we discuss known mechanisms and recent scientific advancements regarding osteosarcoma and its patterns of resistance against chemotherapy, radiation, and other newly-introduced therapeutics.

EMP1 promotes the malignant progression of osteosarcoma through the IRX2/MMP9 axis

BACKGROUND

Previous studies have demonstrated that EMP1 is an oncogene. In this paper, we aim to uncover the role of EMP1 in stimulating the malignant progression of osteosarcoma (OS) by the IRX2/MMP9 axis.

METHODS

EMP1 levels in 49 OS tissues and adjacent ones were detected. Potential correlation between EMP1 level and clinical data of OS patients was determined. Migratory and invasive abilities in SaOS-2 and U2OS cells influenced by EMP1 were examined by Transwell and wound healing assay. The involvement of IRX2 in OS cell metastasis regulated by EMP1 was finally explored.

RESULTS

EMP1 was upregulated in OS tissues than those of normal ones. Higher rates of lymphatic metastasis and distant metastasis were found in OS patients expressing higher level of EMP1, who suffered a worse prognosis. Knockdown of EMP1 inhibited migratory and invasive abilities in OS cells. Protein levels of IRX2 and MMP9 were upregulated after overexpression of EMP1. Rescue experiments verified that IRX2 was involved in EMP1-regulated malignant progression of OS.

CONCLUSIONS

EMP1 is upregulated in OS tissues and closely linked to lymphatic metastasis and distant metastasis. It stimulates the malignant progression of OS through the IRX2/MMP9 axis.

The multiple function of long noncoding RNAs in osteosarcoma progression, drug resistance and prognosis

Osteosarcoma is a bone tumor prevalent in children and young adults. LncRNAs are a family of non-protein-coding transcripts longer than 200 nucleotides. The tumor-related pathological functions of lncRNAs include proliferation, migration, and chemotherapy resistance, all of which have been widely acknowledged in research on osteosarcoma. In addition, compelling evidence suggests that lncRNAs could serve as diagnostic indicators, prognostic biomarkers, and targets for disease treatment. In this review, we systematically summarize how lncRNAs regulate tumorigenesis, invasion and therapeutic resistance. By deepening our knowledge of the relationship between lncRNAs and osteosarcoma, we hope to translate research findings into clinical applications as soon as possible.

Emerging Role of Non-Coding RNAs in Esophageal Squamous Cell Carcinoma

Esophageal squamous cell carcinoma (ESCC) is a highly prevalent tumor and is associated with ethnicity, genetics, and dietary intake. Non-coding RNAs (ncRNAs), specifically microRNAs (miRNAs), long ncRNAs (lncRNAs), and circular RNAs (circRNAs) have been reported as functional regulatory molecules involved in the development of many human cancers, including ESCC. Recently, several ncRNAs have been detected as oncogenes or tumor suppressors in ESCC progression. These ncRNAs influence the expression of specific genes or their associated signaling pathways. Moreover, interactions of ncRNAs are evident in ESCC, as miRNAs regulate the expression of lncRNAs, and further, lncRNAs and circRNAs function as miRNA sponges to compete with the endogenous RNAs. Here, we discuss and summarize the findings of recent investigations into the role of ncRNAs (miRNAs, lncRNAs, and circRNAs) in the development and progression of ESCC and how their interactions regulate ESCC development.

TNF-α/miR-155 axis induces the transformation of osteosarcoma cancer stem cells independent of TP53INP1

MicroRNA-155 (miR-155) has been identified to be overexpressed in various human cancers including osteosarcoma. However, whether the up-regulation of miR-155 is associated with osteosarcoma cancer stem cells (CSCs) is not well understood. In the present study, we showed that miR-155 induced the acquisition of stem-like features in U2OS osteosarcoma cells by increasing the expression of both CSCs surface markers (CD24, CD90, CD133) and CSC-related transcriptional factors (Nanog, SOX2, Oct4, Bim-1). Inflammatory factor TNF-α upregulated the miR-155 expression in U2OS cells and formed a feedback regulatory loop with miR-155. Furthermore, TNF-α/miR-155 axis promoted the cell proliferation, invasion and epithelial-mesenchymal transition (EMT) process in a TP53INP1 independent manner. We also revealed that TNF-α/miR-155 axis induced osteosarcoma CSCs transformation via ERK signaling pathway. These results indicate a crucial role of miR-155 in the acquisition of osteosarcoma CSC phenotype and miR-155 may serve as a potential target in future osteosarcoma therapy.

Chlorogenic acid activates ERK1/2 and inhibits proliferation of osteosarcoma cells

Osteosarcoma (OS) is a very aggressive metastatic pediatric and adolescent tumor. Due to its recurrent development of chemotherapy resistance, clinical outcome for OS patients remains poor. Therefore, discovering more effective anticancer agents is needed. Chlorogenic acid (CGA) is a phenolic compound contained in plant-related products that modulates many cellular functions and inhibits cell proliferation in several cancer types. However, few evidence is available in OS. Here, we investigate the effects of CGA in U2OS, Saos-2, and MG-63 OS cells. By multiple approaches, we demonstrate that CGA acts as anticancer molecule affecting the cell cycle and provoking cell growth inhibition mainly by apoptosis induction. We also provide evidence that CGA strongly activates extracellular-signal-regulated kinase1/2 (ERK1/2). Strikingly, ERK1/2 inhibitor PD98059 sensitizes the cells to CGA. Altogether, our data enforce the evidence of the anticancer activity mediated by CGA and provide the rationale for the development of innovative therapeutic strategies in OS cure.