Therapeutic Target For Osteosarcoma Research Articles

Long non-coding HOXA-AS3 contributes to osteosarcoma progression through the miR-1286/TEAD1 axis

Long non-coding RNA (lncRNA) HOXA cluster antisense RNA 3 (HOXA-AS3) regulates the progression of several types of human malignancy. However, the role and potential mechanism of HOXA-AS3 in osteosarcoma (OS) remain unknown. In this study, upregulation of HOXA-AS3 was observed in OS tissues and cell lines and associated with poor clinical outcomes. Silencing of HOXA-AS3 significantly inhibited the proliferation, migration and invasion of OS cells in vitro and suppressed the tumorigenesis of OS cells in vivo. Furthermore, knockdown of HOXA-AS3 inhibited the proliferation and migration of human umbilical vein endothelial cells (HUVECs) and epithelial-to-mesenchymal transition (EMT) in OS. Further investigation of this mechanism revealed that HOXA-AS3 could directly upregulate the expression of TEAD1 via its competing endogenous RNA (ceRNA) activity on miR-1286. This study clarified the oncogenic roles of the HOXA-AS3/miR-1286/TEAD1 axis in OS progression, suggesting a novel therapeutic target for OS.

Single-Cell RNA Sequencing Pro-angiogenic Macrophage Profiles Reveal Novel Prognostic Biomarkers and Therapeutic Targets for Osteosarcoma.

Osteosarcoma (OS) is a malignant bone tumor that most commonly occurs in children and adolescents. OS patients have a poor prognosis, and 5-year survival rates have rarely improved significantly over the past few decades. OS prognosis may be related to the infiltration of tumor-associated macrophages (TAMs). However, the role of proangiogenic macrophages, a subtype of TAMs, in OS prognosis has not been reported. In this study, seven subtypes of TAMs were identified from single-cell RNA sequencing (scRNA-seq) data that we propose defining as proangiogenic TAMs (Angio-TAMs), interferon-primed TAMs (IFN-TAMs), inflammatory cytokine-enriched TAMs (Inflam-TAMs), immune regulatory TAMs (Reg-TAMs), lipid-associated TAMs (LA-TAMs), and resident-tissue macrophages like TAMs (RTM-TAMs) (containing two subcellular types). In the survival analysis of each macrophage subtype, it was found that patients with Angio-TAMs had the most significant difference in survival. Eight genes associated with Angio-TAMs were obtained by differential expression analysis, and these genes were built into a prognostic model using the LASSO algorithm. Clinical OS case samples were categorized into high-risk and low-risk subgroups using median risk scores. In comparison to the low-risk subgroup, the survival time of the high-risk subgroup was much shorter. Additional studies on immune cell infiltration and immune checkpoint molecule expression in the two risk subgroups were carried out. In immunotherapy response prediction, the Angio-TAM-associated gene risk signature was found to be negatively correlated with immune checkpoint responses. In addition, the associated enriched GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways were mainly involved in the malignant progression of tumors. As suggested by these findings, the Angio-TAM gene risk signature may be an underlying prognostic biomarker and novel therapeutic target for OS patients.Kindly check and confirm whether the ESM file is correctly identifiedWe have checked this file and confirmed that it can be correctly identified.

C/ebpα represses the oncogenic Runx3-Myc axis in p53-deficient osteosarcoma development.

Osteosarcoma (OS) is characterized by TP53 mutations in humans. In mice, loss of p53 triggers OS development, and osteoprogenitor-specific p53-deleted mice are widely used to study the process of osteosarcomagenesis. However, the molecular mechanisms underlying the initiation or progression of OS following or parallel to p53 inactivation remain largely unknown. Here, we examined the role of transcription factors involved in adipogenesis (adipo-TFs) in p53-deficient OS and identified a novel tumor suppressive molecular mechanism mediated by C/ebpα. C/ebpα specifically interacts with Runx3, a p53 deficiency-dependent oncogene, and, in the same manner as p53, decreases the activity of the oncogenic axis of OS, Runx3-Myc, by inhibiting Runx3 DNA binding. The identification of a novel molecular role for C/ebpα in p53-deficient osteosarcomagenesis underscores the importance of the Runx-Myc oncogenic axis as a therapeutic target for OS.

Stylopine: A potential natural metabolite to block vascular endothelial growth factor receptor 2 (VEGFR2) in osteosarcoma therapy.

Vascular endothelial growth factor (VEGF) signals cell survival, cell migration, osteogenesis, cell proliferation, angiogenesis, and vascular permeability by binding to VEGF receptor 2 (VEGFR-2). Osteosarcoma is the most common primary bone cancer, majorly affects young adults. Activation of VEGFR-2 signaling is a therapeutic target for osteosarcoma. The present study aimed to evaluate the potency of stylopine in regulation of the VEGFR-2 signaling pathway and its anti-tumour effect human MG-63 osteosarcoma cells. The in silico study on benzylisoquinoline alkaloids was carried out for analyzing and shortlisting of compounds using a virtual screening, Lipinski's rule, bioavailability graphical RADAR plot, pharmacokinetics, toxicity, and molecular docking studies. Among the benzylisoquinoline alkaloids, stylopine was selected and subjected to in-vitro studies against human MG-63 osteosarcoma cells. Various experiments such as MTT assay, EtBr/AO staining, mitochondrial membrane potential assessment, transwell migration assay, gene expression analysis by a quantitative real time polymerase chain reaction (qRT-PCR) method, SDS-PAGE followed by immunoblotting were performed to evaluate its anti-tumour effect as compared to standard axitinib. The MTT assay indicates that stylopine inhibits cell proliferation in MG-63 cells. Similarly, as confirmed by the EtBr/Ao staining method, the MMP assay indicates that stylopine induces mitochondrial membrane damage and apoptosis as compared to axitinib. Moreover, stylopine inhibits the VEGF-165 induced MG-63 cell migration by a trans-well migration assay. The immunoblotting and qRT-PCR analysis showed that stylopine inhibits the VEGF-165 induced VEGFR2 expression in MG-63 cells. It is concluded that stylopine has potential to regulate VEGFR2 and can inhibit osteosarcoma cells to offer a new drug candidate for the treatment of bone cancer in future.

BARX1 promotes osteosarcoma cell proliferation and invasion by regulating HSPA6 expression

Osteosarcoma (OS) is a bone tumour affecting adolescents. Dysregulation of Barx homeobox 1 (BARX1) expression is involved in various cancers, but its function and mechanism in the process of OS are undefined. This study revealed that BARX1 expression is higher in OS tissue than in adjacent normal tissue. Downregulation of BARX1 in OS cells significantly suppressed their proliferation and migration, whereas enforced expression of exogenous BARX1 exerted the opposite effects on OS cells. Subsequently, heat shock 70-kDa protein 6 (HSPA6) expression was clearly increased after BARX1 overexpression in OS cells, as confirmed by RNA sequencing. The dual-luciferase reporter assay confirmed that HSPA6 expression is directly regulated by BARX1. The in vitro assay indicated that silencing HSPA6 expression attenuated OS proliferation and migration induced by BARX1. A dual immunofluorescence labelling assay provided further evidence that BARX1 was overexpressed and associated with HSPA6 overexpression in OS tumour tissue. In conclusion, BARX1 promotes OS cell proliferation and migration by inducing the expression of HSPA6, which plays an oncogenic role in OS. BARX1 and HSPA6 can potentially act as novel therapeutic targets for OS.

P2RX7 promotes osteosarcoma progression and glucose metabolism by enhancing c-Myc stabilization

BackgroundOsteosarcoma is the most common malignant tumor in bone and its prognosis has reached a plateau in the past few decades. Recently, metabolic reprogramming has attracted increasing attention in the field of cancer research. In our previous study, P2RX7 has been identified as an oncogene in osteosarcoma. However, whether and how P2RX7 promotes osteosarcoma growth and metastasis through metabolic reprogramming remains unexplored.MethodsWe used CRISPR/Cas9 genome editing technology to establish P2RX7 knockout cell lines. Transcriptomics and metabolomics were performed to explore metabolic reprogramming in osteosarcoma. RT-PCR, western blot and immunofluorescence analyses were used to determine gene expression related to glucose metabolism. Cell cycle and apoptosis were examined by flowcytometry. The capacity of glycolysis and oxidative phosphorylation were assessed by seahorse experiments. PET/CT was carried out to assess glucose uptake in vivo.ResultsWe demonstrated that P2RX7 significantly promotes glucose metabolism in osteosarcoma via upregulating the expression of genes related to glucose metabolism. Inhibition of glucose metabolism largely abolishes the ability of P2RX7 to promote osteosarcoma progression. Mechanistically, P2RX7 enhances c-Myc stabilization by facilitating nuclear retention and reducing ubiquitination-dependent degradation. Furthermore, P2RX7 promotes osteosarcoma growth and metastasis through metabolic reprogramming in a predominantly c-Myc-dependent manner.ConclusionsP2RX7 plays a key role in metabolic reprogramming and osteosarcoma progression via increasing c-Myc stability. These findings provide new evidence that P2RX7 might be a potential diagnostic and/or therapeutic target for osteosarcoma. Novel therapeutic strategies targeting metabolic reprogramming appear to hold promise for a breakthrough in the treatment of osteosarcoma.

Molecular features and predictive models identify the most lethal subtype and a therapeutic target for osteosarcoma.

Osteosarcoma is the most common primary malignant bone tumor. The existing treatment regimens remained essentially unchanged over the past 30 years; hence the prognosis has plateaued at a poor level. Precise and personalized therapy is yet to be exploited. One discovery cohort (n=98) and two validation cohorts (n=53 & n=48) were collected from public data sources. We performed a non-negative matrix factorization (NMF) method on the discovery cohort to stratify osteosarcoma. Survival analysis and transcriptomic profiling characterized each subtype. Then, a drug target was screened based on subtypes' features and hazard ratios. We also used specific siRNAs and added a cholesterol pathway inhibitor to osteosarcoma cell lines (U2OS and Saos-2) to verify the target. Moreover, PermFIT and ProMS, two support vector machine (SVM) tools, and the least absolute shrinkage and selection operator (LASSO) method, were employed to establish predictive models. We herein divided osteosarcoma patients into four subtypes (S-I ~ S-IV). Patients of S- I were found probable to live longer. S-II was characterized by the highest immune infiltration. Cancer cells proliferated most in S-III. Notably, S-IV held the most unfavorable outcome and active cholesterol metabolism. SQLE, a rate-limiting enzyme for cholesterol biosynthesis, was identified as a potential drug target for S-IV patients. This finding was further validated in two external independent osteosarcoma cohorts. The function of SQLE to promote proliferation and migration was confirmed by cell phenotypic assays after the specific gene knockdown or addition of terbinafine, an inhibitor of SQLE. We further employed two machine learning tools based on SVM algorithms to develop a subtype diagnostic model and used the LASSO method to establish a 4-gene model for predicting prognosis. These two models were also verified in a validation cohort. The molecular classification enhanced our understanding of osteosarcoma; the novel predicting models served as robust prognostic biomarkers; the therapeutic target SQLE opened a new way for treatment. Our results served as valuable hints for future biological studies and clinical trials of osteosarcoma.

Autophagy and its role in osteosarcoma.

Osteosarcoma (OS) is the most common bone malignancy and preferably occurs in children and adolescents. Despite significant advances in surgery and chemotherapy for OS over the past few years, overall survival rates of OS have reached a bottleneck. Thus, extensive researches aimed at developing new therapeutic targets for OS are urgently needed. Autophagy, a conserved process which allows cells to recycle altered or unused organelles and cellular components, has been proven to play a critical role in multiple biological processes in OS. In this article, we summarized the association between autophagy and proliferation, metastasis, chemotherapy, radiotherapy, and immunotherapy of OS, revealing that autophagy-related genes and pathways could serve as potential targets for OS therapy.

TAF1D Functions as a Novel Biomarker in Osteosarcoma.

Background: The most frequent primary bone cancer in teenagers, osteosarcoma (OS), is particularly aggressive with a high mortality rate. Methods: By combining public databases, OS and non-cancer samples were obtained. The Wilcoxon test and standardized mean difference (SMD) were utilized to evaluate the mRNA expression level of TATA-box binding protein associated factor, RNA polymerase 1 subunit D (TAF1D). The potential of TAF1D to discriminate OS samples from non-cancer samples was revealed by summary receiver operating characteristic curve (sROC). To investigate the prognostic significance, Kaplan‒Meier curve and univariate Cox analysis were performed. Immunohistochemistry (IHC) was used to determine the TAF1D protein expression level. ESTIMATE algorithm and TIMER2.0 database were used to reveal the association between TAF1D expression and the immune microenvironment. Enrichment analysis and potential drug prediction were performed to clarify the underlying molecular mechanisms and possible therapeutic directions of TAF1D. Ultimately, the transcription factors (TFs) and the TAF1D binding site were predicted based on the Cistrome and JASPAR databases. Results: TAF1D was upregulated in OS at the mRNA and protein levels and possessed robust discriminatory power. TAF1D upregulation was suggestive of worse prognosis and enhancement of tumor purity in OS patients. The cell cycle was the most significantly enriched pathway, and NU.1025 was considered to be the potential target agent. Finally, MYC was identified as a TF that regulates the expression of TAF1D. Conclusions: Altogether, TAF1D has the potential to serve as a biological marker and therapeutic target in OS, which could offer new perspectives for OS treatment.

MIR503HG Overexpression Inhibits the Malignant Behaviors of Osteosarcoma Cells by Sponging miR-103a-3p

Osteosarcoma (OS) is the most representative primary bone tumour in children and teenagers. This study explored the regulatory effects of long noncoding RNA MIR503HG (MIR503HG) on the biological functions of OS cells, and further investigated the potential mechanism of MIR503HG function exertion by analyzing the microRNA-103a-3p (miR-103a-3p) in OS cells and tissues. The expression of MIR503HG was examined using reverse transcription-quantitative PCR. OS cell proliferation was assessed by CCK-8 assay. Transwell assay was used to evaluate the migration and invasion of OS cells. The interaction between MIR503HG and miR-103a-3p was detected using the Dual-luciferase reporter assay. Forty-six paired OS tissues were collected, and the expression and correlation of MIR503HG and miR-103a-3p were evaluated. The expression of MIR503HG were significantly decreased in both OS cells and tissues. Over-expression of MIR503HG inhibited OS cell proliferation, migration and invasion. miR-103a-3p was directly targeted by MIR503HG in OS cells, and mediated the inhibitory effects of MIR503HG on OS cell malignant behaviors. miR-103a-3p expression was upregulated in OS tissues, which was negatively correlated with MIR503HG expression levels. The expression of MIR503HG was associated with OS patients' tumor size, differentiation, distant metastasis and clinical stage. Decreased MIR503HG in OS tissues and cell lines served as a tumor suppressor by inhibiting OS cell malignant behaviors through sponging miR-103a-3p. The findings of this study may provide evidence for the development of novel therapeutic targets of OS.

ADAM19 and TUBB1 correlates with tumor infiltrating immune cells and predicts prognosis in osteosarcoma.

Osteosarcoma is the most common type of primary malignant bone tumor. This study aimed to explore potential key prognostic genes and their roles in osteosarcoma. Three microarray datasets for osteosarcoma were downloaded from GEO database. Differentially expressed genes (DEGs) were screened by Limma package. Functional enrichment analysis was performed based on DAVID, GeneMANIA, and Metascape databases. Prognostic value of DEGs was elevated by survival analysis. CIBERSORT was used to assess the infiltrating abundance of 22 immune cells, followed by the Pearson correlation analysis between immune cells and prognosis-related genes. Gene set enrichment analysis and drug-gene interactions prediction were performed for prognosis-related genes. A total of 8 common up-regulated DEGs and 13 common down-regulated DEGs were screened in GSE36001 and GSE56001 datasets. Enrichment analysis showed these DEGs were implicated in platelet activation, SMAD protein phosphorylation, lymphocyte/leukocyte/T cells activation, and cell migration. Survival analysis indicated that elevated expression of ADAM19 and TUBB1 were associated with favorable prognosis. CIBERSORT algorithm revealed higher infiltrating level of CD8 T cells, macrophages M0, and M2 in osteosarcoma. ADAM19 expression positively correlated with naïve B cells and negatively correlated with activated dendritic cells infiltrating abundance. TUBB1 expression positively correlated with gamma delta T cells while negatively correlated with helper follicular T cells infiltrating abundance. Total of 56 drugs were found to target TUBB1. ADAM19 and TUBB1 could be prognostic biomarkers in osteosarcoma. Both their expression correlates with tumor infiltrating immune cells. TUBB1 was a multi-drug target that might be a therapeutic target in osteosarcoma.

Infiltration of LPAR5+ macrophages in osteosarcoma tumor microenvironment predicts better outcomes.

Tumor microenvironment (TME) has been shown to be extensively involved in tumor development. However, the dynamic change of TME components and their effects are still unclear. Here, we attempted to identify TME-related genes that could help predict survival and may be potential therapeutic targets. Data was collected from UCSC Xena and GEO database. ESTIMATE and CIBERSORT algorithms were applied to estimate the components and the proportions of TIICs in TME. We analyzed the gene expression differences of immune components and stromal components, respectively, and finally got the overlapped DEGs. Through protein-protein interaction (PPI) network and univariate Cox regression analysis based on shared DEGs, we screened out and validated the TME-related genes. Focusing on this gene, we analyzed the expression and prognostic value of this gene, and investigated its relationship with immune cells by correlation analysis, single cell analysis, immunohistochemistry and immunofluorescence analysis. Through a series analysis, we found that the proportion of immune and stromal components was an important prognostic factor, and screened out a key gene, LPAR5, which was highly correlated with prognosis and metastasis. And the expression of LPAR5 was positively correlated with immune cells, especially macrophages, indicating LPAR5+ macrophages played an important role in tumor microenvironment of osteosarcoma. Meanwhile, the genes in LPAR5 high expression group were enriched in immune-related activities and pathways, and differentially expressed genes between LPAR5+ macrophages and LPAR5- macrophages were enriched in the biological processes associated with phagocytosis and antigen presentation. What' more, we found that LPAR5 was mainly expressed in TME, and high LPAR5 expression predicting a better prognosis. We identified a TME-related gene, LPAR5, which is a promising indicator for TME remodeling in osteosarcoma. Particularly, LPAR5+ macrophages might have great potential to be a prognostic factor and therapeutic target for osteosarcoma.

ADCK1 is a potential therapeutic target of osteosarcoma

We here showed that ADCK1 (AarF domain-containing kinase 1), a mitochondrial protein, is upregulated in human osteosarcoma (OS) tissues and OS cells. In primary and established OS cells, ADCK1 shRNA or CRISPR/Cas9-induced ADCK1 knockout (KO) remarkably inhibited cell viability, proliferation and migration, and provoked apoptosis activation. Conversely, ectopic ADCK1 overexpression exerted pro-cancerous activity by promoting OS cell proliferation and migration. ADCK1 depletion disrupted mitochondrial functions in OS cells and induced mitochondrial membrane potential reduction, ATP depletion, reactive oxygen species production. Significantly, ADCK1 silencing augmented doxorubicin-induced apoptosis in primary OS cells. mTOR activation is important for ADCK1 expression in OS cells. The mTOR inhibitors, rapamycin and AZD2014, as well as mTOR shRNA, potently decreased ADCK1 expression in primary OS cells. In nude mice, the growth of subcutaneous pOS-1 xenografts was largely inhibited when bearing ADCK1 shRNA or ADCK1 KO construct. Moreover, ADCK1 KO largely inhibited pOS-1 xenograft in situ growth in proximal tibia of nude mice. ADCK1 depletion, apoptosis activation and ATP reduction were detected in pOS-1 xenografts bearing ADCK1 shRNA or ADCK1 KO construct. Together, the mitochondrial protein ADCK1 is required for OS cell growth and is a novel therapeutic target of OS.

Biodegradable Carbon Dioxide-Derived Non-Viral Gene Vectors for Osteosarcoma Gene Therapy.

Osteosarcoma often occurs in children and adolescents with high invasiveness and high mortality. Polo-like kinase 1 (PLK1) overexpressed in most tumors promotes cancer cell proliferation and transformation. PLK1 is considered as a therapeutic target for osteosarcoma. RNA interference-based therapies are employed to combat osteosarcoma through silencing PLK1 gene expression. However, the treatment results remain unsatisfactory due to the lack of a safe and efficient nonviral gene vector. To tackle this hurdle, biodegradable and CO2 -derivative cationic poly(vinylcyclohexene carbonates) (CPCHCs) are used as gene vectors to perform a siPLK1 therapeutic strategy for osteosarcoma treatment. Of those CPCHCs, CPCHC60 demonstrates the most excellent performance in gene transfection efficiency, endo-lysosome escaping, biodegradability, and biosafety. With the treatment of CPCHCs/siRNA nanoparticles, the expression level of PLK1 gene in osteosarcoma cells is significantly down-regulated. Subsequently, cells are arrested in the G2 /M phase and subsequently dead in the form of apoptosis, resulting in significant tumor regression both in vitro and in vivo. This study brings a new insight into the development of superior nonviral gene vectors for practical cancer treatment. Based on the results, the resulting nanoparticle-based gene drug formation is considered to have a highly successful chance in further translational nanomedicine applications.

Identification of pyroptosis-related genes and long non-coding RNAs signatures in osteosarcoma

Osteosarcoma is a highly malignant tumor, with very high disability and fatality rates. However, the overall prognosis is not optimistic. Pyroptosis is a newly discovered cell death modality accompanied by inflammation, which is closely related to varieties of cancers. In this study, the RNA-seq data were downloaded from public databases, the differences in the expression of the pyroptosis-related genes (PRGs) were identified, and the six PRGs signature was established through the univariate and LASSO Cox analysis. The patients were grouped according to the PRGs signature, and the prognosis between the two groups was further compared. In addition, a ten pyroptosis-related lncRNAs (PRLs) prognostic signature was also constructed. Through functional analysis of the differentially expressed genes (DEGs), the immune-related pathways were found to be enriched. The Pearson correlation analysis showed a strong correlation between the pyroptosis-related biomarkers. Finally, we identified a promising biomarker, CHMP4C, which is highly expressed in osteosarcoma. Overexpression of CHMP4C promoted the proliferation, migration and invasion of the osteosarcoma cell. Our results thus provide new evidence for exploring prognostic biomarkers and therapeutic targets of osteosarcoma.

The expression of miR-181b, CYLD, CBX-7, BCL2, and p53 in osteosarcoma patients and correlation with clinicopathological factors.

Osteosarcoma is a common human malignancy with a high mortality rate worldwide. Recent studies have been focused on understanding the involvement of microRNA (miRNAs) in the pathogenesis of osteosarcoma. Therefore, the present study aimed to measure the expression levels of miR-181a, cylindromatosis (CYLD), chromo box homolog 7 (CBX7), B-cell lymphoma 2 (BCL2), and tumor protein p53 in tumor tissue and adjacent normal tissues in patients with osteosarcoma and its relationship with clinicopathological factors. The expression levels of miR-181a, CYLD, CBX7, BCL2, and p53 were measured in 60 patients with osteosarcoma using quantitative real-time polymerase chain reaction. Finally, we compared the relationship between these gene levels and clinicopathological factors in tumor and healthy tissues. Our results showed that the expression levels of miR-181a, BCL2, and p53 were significantly higher in osteosarcoma tissue in comparison with normal tissues (p < .05). On the contrary, CYLD and CBX7 were downregulated in osteosarcoma tumor tissues compared to adjacent healthy tissues (p < .05). In addition, the expression levels of miR-181a in tumor tissues were strongly correlated with patients' age, tumor size, clinical stage, cancer grade, and lymph node metastasis (p < .05). Our findings highlight new insights into understanding the role of miR-181a in the pathogenesis of osteosarcoma. However, further studies are needed to elucidate miRNA as therapeutic targets for osteosarcoma.

ZCCHC12 promotes the progression of osteosarcoma via PI3K/AKT pathway.

Researchers have reported that zinc finger CCHC domain containing 12 gene (ZCCHC12) plays a role in the progression and tumorigenesis of papillary thyroid cancer. However, the biological role of ZCCHC12 in osteosarcoma (OS) remains unknown. ZCCHC12 was highly upregulated in OS cell lines according to our present study. Also, our subsequent assays demonstrated that ZCCHC12 enhanced the proliferation, tumor growth and migration of OS cells. Moreover, the epithelial-mesenchymal transition (EMT) of OS cells was also promoted by ZCCHC12. In addition, downregulation of ZCCHC12 induced apoptosis and S-phase arrest in OS cells. Then, our study indicated that ZCCHC12 exerts its oncogenic function in OS cells by activating the PI3K/AKT pathway. Inhibition of the PI3K/AKT pathway greatly limits the oncogenic function of ZCCHC12 in OS cells. Also, overexpression of ZCCHC12 promotes tumor growth in vivo. Altogether, our study suggests ZCCHC12 promotes OS cells progression by activating the PI3K/AKT pathway. The ZCCHC12 gene may be a novel diagnostic and therapeutic target for OS.

Sphingolipid metabolism is associated with osteosarcoma metastasis and prognosis: Evidence from interaction analysis.

BackgroundMetabolism is widely involved in the occurrence and development of cancer. However, its role in osteosarcoma (OS) has not been elucidated.MethodsThe open-accessed data included in this study were downloaded from The Cancer Genome Atlas (TCGA) database (TARGET-OS project). All the analysis was performed in R environments.ResultsBased on the single sample gene set enrichment analysis algorithm, we quantified 21 metabolism terms in OS patients. Among these, sphingolipid metabolism was upregulated in the metastatic OS tissue and associated with a worse prognosis, therefore aroused our interest and selected for further analysis. Our result showed that sphingolipid metabolism could activate the Notch signaling and angiogenesis pathway, which might be responsible for the metastasis ability and poor prognosis. A protein-protein interaction network was constructed to illustrate the interaction of the differentially expressed genes between high and low sphingolipid metabolism. Immune analysis showed that multiple immune terms were upregulated in patients with high sphingolipid metabolism activity. Then, a prognosis model was established based on the identified DEGs between patients with high and low sphingolipid metabolism, which showed great prediction efficiency. Pathway enrichment showed the pathway of myogenesis, spermatogenesis, peroxisome, KRAS signaling, pancreas beta cells, apical surface, MYC target, WNT beta-catenin signaling, late estrogen response and apical junction was significantly enriched in high risk patients. Moreover, we found that the model genes MAGEB1, NPIPA2, PLA2G4B and MAGEA3 could effectively indicate sphingolipid metabolism and risk group.ConclusionsIn summary, our result showed that sphingolipid metabolism is associated with osteosarcoma metastasis and prognosis, which has the potential to be a therapeutic target for OS.

LONG NON-CODING RNAs AND AUTOPHAGY IN OSTEOSARCOMA

Osteosarcoma (OSA) is an aggressive bone tumor that occurs primarily in children and adolescents worldwide, with a high metastatic and recurrence ability. OSA is characterized by the transformation of mesenchymal cells and the formation of osteoid tissue. Although recent advancements have improved the current therapeutic management of OSA, the clinical outcomes of the disease still remain unsatisfactory. Therefore, it is important to determine the novel diagnostic markers and/or therapeutic targets for OSA. Autophagy is a highly conserved self-degradative process that plays a crucial role in various physiological mechanisms such as survival, homeostasis, development and differentiation. Dysfunction of autophagy is the relationship with the onset and development of several types of cancer, including OSA. Long non-coding ribonucleic acids (lncRNAs), a group of non-coding RNAs, regulate various pathophysiological mechanisms such as inflammation, autophagy and apoptosis. Recent studies investigating the role of lncRNAs in the pathogenesis of OSA have shown that these molecules might have diagnostic and therapeutic importance for the prevention of OSA. Here, we focus on lncRNAs that modulate autophagy in OSA and discuss the potential clinical values of lncRNAs for OSA. The current study contributes to a better understanding of OSA pathogenesis and to the development of novel therapeutic approaches for the prevention of OSA.

A transmembrane protein family gene signature for overall survival prediction in osteosarcoma.

The transmembrane (TMEM) protein family is constituted by a large number of proteins that span the lipid bilayer. Dysregulation of TMEM protein genes widely occurs and is associated with clinical outcomes of patients with multiple tumors. Nonetheless, the significance of TMEM genes in the prognosis prediction of patients with osteosarcoma remains largely unclear. Here, we comprehensively analyzed TMEM protein family genes in osteosarcoma using public resources and bioinformatics methods. Prognosis-related TMEM protein family genes were identified by the univariate Cox regression analysis and were utilized to construct a signature based on six TMEM protein family genes (TMEM120B, TMEM147, TMEM9B, TMEM8A, TMEM59, and TMEM39B) in osteosarcoma. The prognostic signature stratified patients into high- and low-risk groups, and validation in the internal and external cohorts confirmed the risk stratification ability of the signature. Functional enrichment analyses of differentially expressed genes between high- and low-risk groups connected immunity with the prognostic signature. Moreover, we found that M2 and M0 macrophages were the most abundant infiltrated immune cell types in the immune microenvironment, and samples of the high-risk group showed a decreased proportion of M2 macrophages. Single-sample gene set enrichment analysis revealed that the scores of neutrophils and Treg were markedly lower in the high-risk group than these in the low-risk group in The Cancer Genome Atlas and GSE16091 cohorts. As for the related immune functions, APC co-inhibition and cytolytic activity exhibited fewer active levels in the high-risk group than that in the low-risk group in both cohorts. Of the six TMEM genes, the expression of TMEM9B was lower in the high-risk group than in the low-risk group and was positively associated with the overall survival of osteosarcoma patients. In conclusion, our TMEM protein family gene-based signature is a novel and clinically useful prognostic biomarker for osteosarcoma patients, and TMEM9B might be a potential therapeutic target in osteosarcoma.