Bone cancer: Is the osteosarcoma genome targetable?

Integration of single-cell sequencing and bulk expression data reveals chemokine signaling pathway in proliferating cells is associated with the survival outcome of osteosarcoma

BACKGROUND

Osteosarcoma, as the most common primary bone malignancy, is urgent to be well-studied on the biomarkers and therapeutic targets to improve the five-year survival rate. Transcriptomic analysis using single-cell RNA or bulk RNA sequencing has been developed to detect biomarkers in various cancer types.

METHODS AND RESULTS

We applied Scissor to combine single-cell RNA-seq data and bulk transcriptome data of osteosarcoma, providing cell-level information and sample phenotypes to identify the survival-associated cell subpopulations. By investigating the differences between the survival-associated cell subpopulations, we identified CCL21, CCL22, CCL24, CXCL11, CXCL12, CXCL13, GNAI2, and RAC2 in the proliferating cells that are significantly associated with osteosarcoma patient outcome. Then we assigned the risk score for each sample based on the cell proportion-normalized gene expression and validated it in the public dataset.

CONCLUSIONS

This study provides the clinical insight that chemokine signaling pathway genes (CCL21, CCL22, CCL24, CXCL11, CXCL12, CXCL13, GNAI2, and RAC2) in proliferating cells might be the potential biomarkers for treatment of osteosarcoma.

Dog breeds and conformations predisposed to osteosarcoma in the UK: a VetCompass study

BACKGROUND

Osteosarcoma is a malignant bone neoplasia that has high welfare consequences for affected dogs. Awareness of breed and canine conformational risk factors for osteosarcoma can assist with earlier diagnosis and improved clinical management. Study of osteosarcoma in dogs also offers translational value for humans. Anonymised clinical data within VetCompass on dogs under primary veterinary care in the UK were searched for osteosarcoma cases. Descriptive statistics reported overall and breed-specific prevalence. Risk factor analysis used multivariable logistic regression modelling.

RESULTS

From 905,552 study dogs, 331 osteosarcoma cases were confirmed yielding a one-year period prevalence of 0.037% (95% CI: 0.033-0.041). Breeds with the highest annual prevalence were the Scottish Deerhound (3.28%, 95% CI 0.90-8.18), Leonberger (1.48%, 95% CI 0.41- 3.75), Great Dane (0.87%, 95% CI 0.43- 1.55) and Rottweiler (0.84%, 95% CI 0.64-1.07). The median age at diagnosis was 9.64 years (IQR: 7.97-11.41). Following multivariable modelling, 11 breeds showed increased odds of osteosarcoma compared with crossbred dogs. Breeds with the highest odds included Scottish Deerhound (OR 118.40, 95% CI 41.12-340.95), Leonberger (OR 55.79, 95% CI 19.68-158.15), Great Dane (OR 34.24, 95% CI 17.81-65.83) and Rottweiler (OR 26.67, 95% CI 18.57-38.29). Compared with breeds with mesocephalic skull conformation, breeds with dolichocephalic skull conformation (OR 2.72, 95% CI 2.06-3.58) had increased odds while breeds with brachycephalic skull conformation showed reduced odds (OR 0.50, 95% CI 0.32-0.80). Chondrodystrophic breeds had 0.10 times the odds (95% CI 0.06-0.15) compared with non-chondrodystrophic breeds. Increasing adult bodyweight was associated with increasing odds of osteosarcoma.

CONCLUSIONS

The current study cements the concept that breed, bodyweight and longer leg or longer skull length are all strong risk factors for osteosarcoma in dogs. With this awareness, veterinarians can update their clinical suspicion and judgement, breeders can select towards lower-risk animals, and researchers can robustly define more useful study populations for fundamental and translational bioscience.

ITGB3 promotes cisplatin resistance in osteosarcoma tumors

OBJECTIVE

Osteosarcoma is the most malignant and common primary bone tumor with a high rate of recurrence that mainly occurs in children and young adults. Therefore, it is vital to facilitate the development of novel effective therapeutic means and improve the overall prognosis of osteosarcoma patients via a deeper understanding of the mechanisms of chemoresistance in osteosarcoma progression.

METHODS

In this research, the relationship between ITGB3 and the clinical characteristics of patients was detected through analysis of publicly available clinical datasets. The expression of ITGB3 was analysis in collected human osteosarcoma tissues. In addition, the potential functions of ITGB3 in the cisplatin resistance of osteosarcoma cells were investigated in vitro and in tumor xenotransplantation. Finally, the molecular mechanism of ITGB3 in the progression and recurrence of osteosarcoma were explored via transcriptome analysis.

RESULTS

ITGB3 was identified as a potential regulator of tumorigenicity and cisplatin resistance in relapsed osteosarcoma. Furthermore, the decreased osteosarcoma cell proliferation and migration ability in ITGB3 knockout osteosarcoma cells were related to increased apoptosis and slowing cell cycle progression. In addition, ITGB3 had a positive correlation with cisplatin resistance in cells and tumor xenografts in mice. Accordingly, ITGB3 performed the functions of proliferation and cisplatin resistance in osteosarcoma through the MAPK and VEGF signaling pathways.

CONCLUSION

Our results will contribute to a better understanding of the function and mechanism of ITGB3 in osteosarcoma cisplatin resistance and provide a novel therapeutic target to decrease cisplatin resistance and tumor recurrence in osteosarcoma patients.

EVI2B Is a Prognostic Biomarker and Is Correlated with Monocyte and Macrophage Infiltration in Osteosarcoma Based on an Integrative Analysis

Osteosarcoma (OS) is the most common malignant bone tumor. However, treatment strategies have not changed over the past 30 years. The relationship between OS and the immune microenvironment may provide a basis for the establishment of novel therapeutic targets. In this study, a large-scale gene expression dataset (GSE42352) was used to identify key genes in OS. A Target-OS dataset from the Cancer Genome Atlas was used as a validation set. Ecotropic viral integration site 2B (EVI2B) was significantly upregulated in OS tumor samples. Differentially expressed genes (DEGs) were identified between samples with high and low EVI2B expression in both the test and validation cohorts. The top three functions of DEGs determined by a gene set enrichment analysis (GSEA) were chemokine signaling, cytokine-cytokine receptor interaction, and Human T-cell leukemia virus 1 infection. A prognostic prediction model including EVI2B, DOCK2, and CD33 was constructed by a Cox regression analysis. This model indicated that EVI2B is an independent protective prognostic marker in OS. An analysis of immune infiltration further showed that high EVI2B expression levels were correlated with high levels of macrophage infiltration. Protein expression data derived from the Human Protein Atlas suggested EVI2B to be highly expressed in monocytes. Finally, we validated the elevated expression of EVI2B in OS cell lines and OS tissue samples; these results were consistent with those of the analyses of the GSE42352 and Target-OS datasets. Our integrative bioinformatics analysis and experimental results provide clear evidence for the prognostic value of EVI2B in OS and its close relationship with monocyte and macrophage infiltration.

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

Background

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.

Methods

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.

Results

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.

Conclusion

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.

Chidamide augment sorafenib-derived anti-tumor activities in human osteosarcoma cells lines and xenograft mouse model

Previous studies have showed promising but short-lived activity of sorafenib in osteosarcoma treatments. Researches have suggested ameliorated sensitivity to standard dose of conventional cancer therapies in combination with histone deacetylase inhibitors (HDACis) through various mechanisms. Herein, for the first time, we exploited the synergism of combination therapies with sorafenib and chidamide, a member of HDACis, in the control of OS using human OS cell lines and OS xenograft mouse model and discussed interactive mechanisms between the two drugs. The combination therapy exerted a strong synergism in the inhibition of OS cell proliferation, meanwhile prominently induced cell apoptosis and cell cycle arrest in G0/G1 phase in OS cells with increased expression of MCL-1, decreased expression of caspase-3 and P21, along with diminished level of the overlapped protein P-ERK1/2. Furthermore, oral administration of the combined treatment led to a more optical therapeutic outcome, including lower degrees of tumoral cell proliferation, greater extent of apoptosis, along with induction of cell cycle arrest in tumor tissues, while exhibiting minimal toxicity. This study shows that the combination of sorafenib and chidamide can combat OS in a synergistic fashion and prompts the promising development of innovative combined therapeutic strategies for OS.

The insertion and dysregulation of transposable elements in osteosarcoma and their association with patient event-free survival

The dysregulation of transposable elements (TEs) has been explored in a variety of cancers. However, TE activities in osteosarcoma (OS) have not been extensively studied yet. By integrative analysis of RNA-seq, whole-genome sequencing (WGS), and methylation data, we showed aberrant TE activities associated with dysregulations of TEs in OS tumors. Specifically, expression levels of LINE-1 and Alu of different evolutionary ages, as well as subfamilies of SVA and HERV-K, were significantly up-regulated in OS tumors, accompanied by enhanced DNA repair responses. We verified the characteristics of LINE-1 mediated TE insertions, including target site duplication (TSD) length (centered around 15 bp) and preferential insertions into intergenic and AT-rich regions as well as intronic regions of longer genes. By filtering polymorphic TE insertions reported in 1000 genome project (1KGP), besides 148 tumor-specific somatic TE insertions, we found most OS patient-specific TE insertions (3175 out of 3326) are germline insertions, which are associated with genes involved in neuronal processes or with transcription factors important for cancer development. In addition to 68 TE-affected cancer genes, we found recurrent germline TE insertions in 72 non-cancer genes with high frequencies among patients. We also found that +/− 500 bps flanking regions of transcription start sites (TSS) of LINE-1 (young) and Alu showed lower methylation levels in OS tumor samples than controls. Interestingly, by incorporating patient clinical data and focusing on TE activities in OS tumors, our data analysis suggested that higher TE insertions in OS tumors are associated with a longer event-free survival time.

Additively manufactured patient-specific prosthesis for tumor reconstruction: Design, process, and properties

Design and processing capabilities of additive manufacturing (AM) to fabricate complex geometries continues to drive the adoption of AM for biomedical applications. In this study, a validated design methodology is presented to evaluate AM as an effective fabrication technique for reconstruction of large bone defects after tumor resection in pediatric oncology patients. Implanting off-the-shelf components in pediatric patients is especially challenging because most standard components are sized and shaped for more common adult cases. While currently reported efforts on AM implants are focused on maxillofacial, hip and knee reconstructions, there have been no reported studies on reconstruction of proximal humerus tumors. A case study of a 9-year-old diagnosed with proximal humerus osteosarcoma was used to develop a patient-specific AM prosthesis for the humerus following tumor resection. Commonly used body-centered cubic (BCC) structures were incorporated at the surgical neck and distal interface in order to increase the effective surface area, promote osseointegration, and reduce the implant weight. A patient-specific prosthesis was fabricated using electron beam melting method from biocompatible Ti-6Al-4V. Both computational and biomechanical tests were performed on the prosthesis to evaluate its biomechanical behavior under varying loading conditions. Morphological analysis of the construct using micro-computed tomography was used to compare the as-designed and as-built prosthesis. It was found that the patient-specific prosthesis could withstand physiologically-relevant loading conditions with minimal permanent deformation (82 μm after 105 cycles) at the medial aspect of the porous surgical neck. These outcomes support potential translation of the patient-specific AM prostheses to reconstruct large bone defects following tumor resection.

The Role of IGF/IGF-IR-Signaling and Extracellular Matrix Effectors in Bone Sarcoma Pathogenesis

Simple Summary

Bone sarcomas are mesenchymal origin tumors. Bone sarcoma patients show a variable response or do not respond to chemotherapy. Notably, improving efficient chemotherapy approaches, dealing with chemoresistance, and preventing metastasis pose unmet challenges in sarcoma therapy. Insulin-like growth factors 1 and 2 (IGF-1 and -2) and their respective receptors are a multifactorial system that significantly contributes to bone sarcoma pathogenesis. Most clinical trials aiming at the IGF pathway have had limited success. Developing combinatorial strategies to enhance antitumor responses and better classify the patients that could best benefit from IGF-axis targeting therapies is in order. A plausible approach for developing a combinatorial strategy is to focus on the tumor microenvironment (TME) and processes executed therein. Herewith, we will discuss how the interplay between IGF-signaling and the TME constituents affects bone sarcomas’ basal functions and their response to therapy. Potential direct and adjunct therapeutical implications of the extracellular matrix (ECM) effectors will also be summarized.

Abstract

Bone sarcomas, mesenchymal origin tumors, represent a substantial group of varying neoplasms of a distinct entity. Bone sarcoma patients show a limited response or do not respond to chemotherapy. Notably, developing efficient chemotherapy approaches, dealing with chemoresistance, and preventing metastasis pose unmet challenges in sarcoma therapy. Insulin-like growth factors 1 and 2 (IGF-1 and -2) and their respective receptors are a multifactorial system that significantly contributes to bone sarcoma pathogenesis. Whereas failures have been registered in creating novel targeted therapeutics aiming at the IGF pathway, new agent development should continue, evaluating combinatorial strategies for enhancing antitumor responses and better classifying the patients that could best benefit from these therapies. A plausible approach for developing a combinatorial strategy is to focus on the tumor microenvironment (TME) and processes executed therein. Herewith, we will discuss how the interplay between IGF-signaling and the TME constituents affects sarcomas’ basal functions and their response to therapy. This review highlights key studies focusing on IGF signaling in bone sarcomas, specifically studies underscoring novel properties that make this system an attractive therapeutic target and identifies new relationships that may be exploited. Potential direct and adjunct therapeutical implications of the extracellular matrix (ECM) effectors will also be summarized.

Regulatory Role of N6-methyladenosine (m6A) Modification in Osteosarcoma

Osteosarcoma is the most common primary bone malignancy, typically occurring in childhood or adolescence. Unfortunately, the clinical outcomes of patients with osteosarcoma are usually poor because of the aggressive nature of this disease and few treatment advances in the past four decades. N6-methyladenosine (m⁶A) is one of the most extensive forms of RNA modification in eukaryotes found both in coding and non-coding RNAs. Accumulating evidence suggests that m⁶A-related factors are dysregulated in multiple osteosarcoma processes. In this review, we highlight m⁶A modification implicated in osteosarcoma, describing its pathophysiological role and molecular mechanism, as well as future research trends and potential clinical application in osteosarcoma.

Histone demethylase KDM5A promotes tumorigenesis of osteosarcoma tumor

Osteosarcoma is a primary bone malignancy with a high rate of recurrence and poorer prognosis. Therefore, it is of vital importance to explore novel prognostic molecular biomarkers and targets for more effective therapeutic approaches. Previous studies showed that histone demethylase KDM5A can increase the proliferation and metastasis of several cancers. However, the function of KDM5A in the carcinogenesis of osteosarcoma is not clear. In the current study, KDM5A was highly expressed in osteosarcoma than adjacent normal tissue. Knockdown of KDM5A suppressed osteosarcoma cell proliferation and induced apoptosis. Moreover, knockdown of KDM5A could increase the expression level of P27 (cell-cycle inhibitor) and decrease the expression of Cyclin D1. Furthermore, after knockout of KDM5A in osteosarcoma cells by CRISPR/Cas9 system, the tumor size and growth speed were inhibited in tumor-bearing nude mice. RNA-Seq of KDM5A-KO cells indicated that interferon, epithelial–mesenchymal transition (EMT), IL6/JAK/STAT3, and TNF-α/NF-κB pathway were likely involved in the regulation of osteosarcoma cell viability. Taken together, our research established a role of KDM5A in osteosarcoma tumorigenesis and progression.

High SENP3 Expression Promotes Cell Migration, Invasion, and Proliferation by Modulating DNA Methylation of E-Cadherin in Osteosarcoma

SENP3, a sentrin/SUMO2/3-specific protease, is recognized as a transcriptional factor that accumulates under cellular oxidative stress and plays a significant role in the removal of SUMO2/3 modification. In our study, we examined a TCGA dataset and found that the transcripts per million (TPM) value of SENP3 is high in sarcoma, including osteosarcoma (OS). We found that SENP3 was highly expressed in OS cancer tissues when compared with osteofibrous dysplasia tissues. The survival data of SENP3 in TCGA showed that the sarcoma patients with higher SENP3 expression levels showed poor prognosis. In vitro, SENP3 knockdown in OS cancer cells inhibited cell proliferation, migration, and invasion and induced apoptosis. In contrast, SENP3 overexpression reversed these effects. Next, we found that SENP3 inhibited the expression of E-cadherin (E-Cad) by increasing methylation of the E-Cad promoter. Finally, E-Cad expression was increased in the OS cell line MG63 following methylation, and the cell proliferation, migration, and invasion capacity were decreased. In summary, SENP3 played a significant role in OS carcinogenesis and may act as a potential biomarker in the diagnosis and treatment of OS.

Clinical significance of serum soluble B7-H3 in patients with osteosarcoma

Background

Increasing data has indicated an association between increased soluble B7-H3 (sB7-H3) levels and unfavorable prognosis in patients with malignancies. However, the level of sB7-H3 and its clinical significance in osteosarcoma (OS) are not well known. In this present study, we investigated whether sB7-H3 levels in serum could be as a tool for differential diagnosis of OS patients.

Methods

Peripheral blood samples from healthy controls, benign bone tumors, and OS patients were collected. Levels of sB7-H3 in serum samples were measured by enzyme-linked immunosorbent assays. The correlation between OS-derived sB7-H3 and clinical features was analyzed, and prognostic significance of the sB7-H3 concentrations and tumor expressions of the biomarkers was then evaluated.

Results

sB7-H3 concentrations were significantly increased in patients with OS than in osteochondroma patients, bone fibrous dysplasia patients and healthy people (p < 0.05, respectively). Using 60.94 ng/mL as a cutoff value, the sensitivity and specificity of sB7-H3 was to differentiate between OS patients and other bone benign tumor patients were 75.7% and 83.8%, respectively. In addition, upregulated serum sB7-H3 in patients with OS associated with tumor differentiation, tumor stage, and metastasis status (p < 0.05, respectively). The area under the curve value for sB7-H3 (0.868) was markedly higher than those for ALP (0.713) and CA125 (0.789) for differentiating between OS patients and other begin bone tumor patients.

Conclusions

We demonstrated that enhanced sB7-H3 levels correlated with the clinical characteristics of OS patients, and B7-H3 might be a potential biomarker and associated with the pathogenesis of OS.

Serum Antibodies Against Simian Virus 40 Large T Antigen, the Viral Oncoprotein, in Osteosarcoma Patients

Human osteosarcoma (OS) is a rare human cancer, mostly occurring in children and adolescents. Simian virus 40 (SV40 = Macaca mulatta polyomavirus 1) sequences have been detected in different human cancers, including osteosarcoma. SV40 is an oncogenic virus in vivo, whereas it transforms different kinds of mammalian cells, as well as distinct human cell types. SV40 injected in rodents induces tumors of different histotypes, such as bone and brain tumors. Herein, the association between OS and SV40 large T antigen (Tag) was studied by employing indirect ELISAs using synthetic peptides that mimic different epitopes of the SV40 Tag, the viral oncoprotein. Indirect ELISAs were used to detect serum IgG antibodies against this oncogenic virus in samples from OS patients. Controls were sera from healthy subjects (HS) and oncological patients affect by breast cancer (BC), which is not associated with SV40. It turned out that sera of OS patients had a higher prevalence of SV40 Tag antibodies, 35%, compared to HS, 20% and BC, 19%, respectively. The different prevalence of SV40 Tag antibodies revealed in OS vs. HS and vs. BC is statistically significant with P < 0.05 and P < 0.01, respectively. Our immunological data indicate a significantly higher prevalence of antibodies against SV40 Tag epitopes in serum samples from OS patients compared to HS and BC, the controls. These results suggest an association between OS and SV40 Tag, indicating that this oncogenic virus may be a cofactor in OS development.