Genome-wide association study identifies two susceptibility loci for osteosarcoma

MiR-1281, a p53-responsive microRNA, impairs the survival of human osteosarcoma cells upon ER stress via targeting USP39

MicroRNAs (miRNAs) are small regulatory non-coding RNAs that have been reported to play an important role in a variety of cellular functions. Recent studies indicated that some miRNAs are involved in regulating endoplasmic reticulum (ER) stress adaptation. However, the miRNAs were still unknown in osteosarcoma. In this study, we demonstrated that miR-1281 induced by ER stress promoted cell apoptosis and decreased ER stress adaptation of osteosarcoma in vitro and in vivo. Further mechanistic studies revealed that p53, an important tumor suppressor, directly bound to the promoter of miR-1281, leading to its increase under ER stress. Additionally, our data suggest that USP39 was the target of miR-1281 and participated in ER stress-induced cell apoptosis. Thus, our findings suggest a new role for miR-1281 in osteosarcoma and suggest that the p53-dependent, miR-1281-mediated USP39 pathway inhibits the survival of human osteosarcoma cells under ER stress.

Adenovirus-mediated small interfering RNA targeting ezrin induces apoptosis and inhibits metastasis of human osteosarcoma MG-63 cells

Osteosarcoma is a disease prone to recurrence and metastasis, and adenovirus expression vector is frequently studied as a therapeutic target of osteosarcoma in recent years. The present study attempts to explore the effect of adenovirus-mediated siRNA targetting ezrin on the proliferation, migration, invasion, and apoptosis of human osteosarcoma MG-63 cells. Human osteosarcoma MG-63 cell line was selected for construction of recombinant adenovirus vector. The mRNA and protein levels of ezrin, Bcl2-associated X protein (Bax), B cell lymphoma-2 (Bcl-2), p21, p53, Caspase-3, matrix metalloproteinase (MMP) 2 (MMP-2) and MMP-9, Cyclin D1, and cyclin-dependent kinase 4a (CDK4a) were determined. Through ELISA, the levels of Caspase-3, MMP-2 and MMP-9 were examined. Finally, human osteosarcoma MG-63 cell viability, growth, invasion, migration, and apoptosis were detected. Initially, adenovirus expression vector of ezrin was constructed by ezrin 2 siRNA sequence. Adenovirus-mediated siRNA targetting ezrin reduced expression of ezrin in MG-63 cells. The results revealed that adenovirus-mediated siRNA targetting ezrin elevated expression levels of Bax, p21, p53, and Caspase-3, Cyclin D1, and CDK4a and reduced expression levels of Bcl-2, MMP-2 and MMP-9. Furthermore, adenovirus-mediated siRNA targetting ezrin inhibited human osteosarcoma MG-63 cell viability, growth, invasion, and migration, and promoted apoptosis. Our study demonstrates that adenovirus-mediated siRNA targetting ezrin can induce apoptosis and inhibit the proliferation, migration, and invasion of human osteosarcoma MG-63 cells.

Tolerance to sustained activation of the cAMP/Creb pathway activity in osteoblastic cells is enabled by loss of p53

The loss of p53 function is a central event in the genesis of osteosarcoma (OS). How mutation of p53 enables OS development from osteoblastic lineage cells is poorly understood. We and others have reported a key role for elevated and persistent activation of the cAMP/PKA/Creb1 pathway in maintenance of OS. In view of the osteoblast lineage being the cell of origin of OS, we sought to determine how these pathways interact within the context of the normal osteoblast. Normal osteoblasts (p53 WT) rapidly underwent apoptosis in response to acute elevation of cAMP levels or activity, whereas p53-deficient osteoblasts tolerated this aberrant cAMP/Creb level and activity. Using the p53 activating small-molecule Nutlin-3a and cAMP/Creb1 activator forskolin, we addressed the question of how p53 responds to the activation of cAMP. We observed that p53 acts dominantly to protect cells from excessive cAMP accumulation. We identify a Creb1-Cbp complex that functions together with and interacts with p53. Finally, translating these results we find that a selective small-molecule inhibitor of the Creb1-Cbp interaction demonstrates selective toxicity to OS cells where this pathway is constitutively active. This highlights the cAMP/Creb axis as a potentially actionable therapeutic vulnerability in p53-deficient tumors such as OS. These results define a mechanism through which p53 protects normal osteoblasts from excessive or abnormal cAMP accumulation, which becomes fundamentally compromised in OS.

Canine sarcomas as a surrogate for the human disease

Pet dogs are becoming increasingly recognized as a population with the potential to inform medical research through their treatment for a variety of maladies by veterinary health professionals. This is the basis of the One Health initiative, supporting the idea of collaboration between human and animal health researchers and clinicians to study spontaneous disease processes and treatment in animals to inform human health. Cancer is a major health burden in pet dogs, accounting for approximately 30% of deaths across breeds. As such, pet dogs with cancer are becoming increasingly recognized as a resource for studying the pharmacology and therapeutic potential of anticancer drugs and therapies under development. This was recently highlighted by a National Academy of Medicine Workshop on Comparative Oncology that took place in mid-2015 (http://www.nap.edu/21830). One component of cancer burden in dogs is their significantly higher incidence of sarcomas as compared to humans. This increased incidence led to canine osteosarcoma being an important component in the development of surgical approaches for osteosarcoma in children. Included in this review of sarcomas in dogs is a description of the incidence, pathology, molecular characteristics and previous translational therapeutic studies associated with these tumors. An understanding of the patho-physiological and molecular characteristics of these naturally occurring canine sarcomas holds great promise for effective incorporation into drug development schemas, for evaluation of target modulation or other pharmacodynamic measures associated with therapeutic response. These data could serve to supplement other preclinical data and bolster clinical investigations in tumor types for which there is a paucity of human patients for clinical trials.

Two HLA Class II Gene Variants Are Independently Associated with Pediatric Osteosarcoma Risk

Background: The genetic etiology of osteosarcoma remains poorly understood despite the publication of a genome-wide association study. Association between HLA genetic variants and risk of several cancers has been observed, but HLA variation is not well captured by standard SNP arrays.Methods: We genotyped 207 Californian pediatric osteosarcoma cases and 696 controls of European ancestry using a custom genome-wide array supplemented with approximately 6,000 additional probes across the MHC region. We subsequently imputed 4-digit classical HLA alleles using a reference panel of 5,225 individuals who underwent high-resolution HLA typing via next-generation sequencing. Case-control comparisons were adjusted for ancestry-informative principal components, and top associations from the discovery analysis underwent replication in an independent dataset of 657 cases and 1,183 controls.Results: Three highly correlated HLA class II variants (r ² = 0.33-0.98) were associated with osteosarcoma risk in discovery analyses, including HLA-DRB1*0301 (OR = 0.52; P = 3.2 × 10^-3), HLA-DQA1*0501 (OR = 0.74; P = 0.031), and HLA-DQB1*0201 (OR = 0.51; P = 2.7 × 10^-3). Similar associations were observed in the replication data (P _range = 0.011-0.037). Meta-analysis of the two datasets identified HLA-DRB1*0301 as the most significantly associated variant (OR_meta = 0.62; P _meta = 1.5 × 10^-4), reaching Bonferroni-corrected statistical significance. The meta-analysis also revealed a second significant independent signal at HLA-DQA1*01:01 (OR_meta = 1.33, P _meta = 1.2 × 10^-3), and a third suggestive association at HLA-DQB1*0302 (OR_meta = 0.73, P _meta = 6.4 × 10^-3).Conclusions: Multiple independent HLA class II alleles may influence osteosarcoma risk.Impact: Additional work is needed to extend our observations to other patient populations and to clarify the potential causal mechanisms underlying these associations. Understanding immunologic contributions to the etiology of osteosarcoma may inform rational therapeutic targets. Cancer Epidemiol Biomarkers Prev; 27(10); 1151-8. ©2018 AACR.

A Bayesian Gene-Based Genome-Wide Association Study Analysis of Osteosarcoma Trio Data Using a Hierarchically Structured Prior

Osteosarcoma is considered to be the most common primary malignant bone cancer among children and young adults. Previous studies suggest growth spurts and height to be risk factors for osteosarcoma. However, studies on the genetic cause are still limited given the rare occurrence of the disease. In this study, we investigated in a family trio data set that is composed of 209 patients and their unaffected parents and conducted a genome-wide association study (GWAS) to identify genetic risk factors for osteosarcoma. We performed a Bayesian gene-based GWAS based on the single-nucleotide polymorphism (SNP)-level summary statistics obtained from a likelihood ratio test of the trio data, which uses a hierarchically structured prior that incorporates the SNP-gene hierarchical structure. The Bayesian approach has higher power than SNP-level GWAS analysis due to the reduced number of tests and is robust by accounting for the correlations between SNPs so that it borrows information across SNPs within a gene. We identified 217 genes that achieved genome-wide significance. Ingenuity pathway analysis of the gene set indicated that osteosarcoma is potentially related to TP53, estrogen receptor signaling, xenobiotic metabolism signaling, and RANK signaling in osteoclasts.

SETD2 Is Recurrently Mutated in Whole-Exome Sequenced Canine Osteosarcoma

Osteosarcoma is a debilitating bone cancer that affects humans, especially children and adolescents. A homologous form of osteosarcoma spontaneously occurs in dogs, and its differential incidence observed across breeds allows for the investigation of tumor mutations in the context of multiple genetic backgrounds. Using whole-exome sequencing and dogs from three susceptible breeds (22 golden retrievers, 21 Rottweilers, and 23 greyhounds), we found that osteosarcoma tumors show a high frequency of somatic copy-number alterations (SCNA), affecting key oncogenes and tumor-suppressor genes. The across-breed results are similar to what has been observed for human osteosarcoma, but the disease frequency and somatic mutation counts vary in the three breeds. For all breeds, three mutational signatures (one of which has not been previously reported) and 11 significantly mutated genes were identified. TP53 was the most frequently altered gene (83% of dogs have either mutations or SCNA in TP53), recapitulating observations in human osteosarcoma. The second most frequently mutated gene, histone methyltransferase SETD2, has known roles in multiple cancers, but has not previously been strongly implicated in osteosarcoma. This study points to the likely importance of histone modifications in osteosarcoma and highlights the strong genetic similarities between human and dog osteosarcoma, suggesting that canine osteosarcoma may serve as an excellent model for developing treatment strategies in both species.Significance: Canine osteosarcoma genomics identify SETD2 as a possible oncogenic driver of osteosarcoma, and findings establish the canine model as a useful comparative model for the corresponding human disease. Cancer Res; 78(13); 3421-31. ©2018 AACR.

Identification of key gene modules for human osteosarcoma by co-expression analysis

BACKGROUND

Osteosarcoma is a type of bone cancer casting huge threat to the human health worldwide. Previously, gene expression analyses were performed to identify biomarkers for cancer; however, systemic co-expression analysis for osteosarcoma is still in need. The aim of this study was to construct a gene co-expression network that predicts clusters of candidate genes associated with the pathogenesis of osteosarcoma.

METHODS

Here, we extracted the large scale of datasets from the GEO database. With systematical approaches, we identified the co-expression modules by using weighted gene co-expression network analysis (WGCNA) and investigated the functional enrichments of important modules at GO and KEGG terms.

RESULTS

First, seven co-expression modules, which contain different genes, were conducted for 2228 genes in the 22 human osteosarcoma samples. Then, correlation study showed that the hub genes between pairwise modules displayed great differences. Lastly, functional enrichments of the co-expression modules showed that the module 5 enriched in immune response, antigen processing, and presentation, which is in consistence with GO result. Therefore, we speculated that the module 5 may play a key role in the pathogenesis of osteosarcoma.

CONCLUSIONS

Here, we speculated that genes of the module 5 were the essential genes that were associated to human osteosarcoma. Together, our findings not only provided outline of co-expression gene modules for human osteosarcoma, but also promoted the understanding of these modules at functional aspects.

Genome-wide association study identifies the GLDC/IL33 locus associated with survival of osteosarcoma patients

Survival rates for osteosarcoma, the most common primary bone cancer, have changed little over the past three decades and are particularly low for patients with metastatic disease. We conducted a multi-institutional genome-wide association study (GWAS) to identify germline genetic variants associated with overall survival in 632 patients with osteosarcoma, including 523 patients of European ancestry and 109 from Brazil. We conducted a time-to-event analysis and estimated hazard ratios (HR) and 95% confidence intervals (CI) using Cox proportional hazards models, with and without adjustment for metastatic disease. The results were combined across the European and Brazilian case sets using a random-effects meta-analysis. The strongest association after meta-analysis was for rs3765555 at 9p24.1, which was inversely associated with overall survival (HR = 1.76; 95% CI 1.41-2.18, p = 4.84 × 10-7 ). After imputation across this region, the combined analysis identified two SNPs that reached genome-wide significance. The strongest single association was with rs55933544 (HR = 1.9; 95% CI 1.5-2.4; p = 1.3 × 10-8 ), which localizes to the GLDC gene, adjacent to the IL33 gene and was consistent across both the European and Brazilian case sets. Using publicly available data, the risk allele was associated with lower expression of IL33 and low expression of IL33 was associated with poor survival in an independent set of patients with osteosarcoma. In conclusion, we have identified the GLDC/IL33 locus on chromosome 9p24.1 as associated with overall survival in patients with osteosarcoma. Further studies are needed to confirm this association and shed light on the biological underpinnings of this susceptibility locus.

Genetic susceptibility to bone and soft tissue sarcomas: a field synopsis and meta-analysis

Background

The genetic architecture of bone and soft tissue sarcomas susceptibility is yet to be elucidated. We aimed to comprehensively collect and meta-analyze the current knowledge on genetic susceptibility in these rare tumors.

Methods

We conducted a systematic review and meta-analysis of the evidence on the association between DNA variation and risk of developing sarcomas through searching PubMed, The Cochrane Library, Scopus and Web of Science databases. To evaluate result credibility, summary evidence was graded according to the Venice criteria and false positive report probability (FPRP) was calculated to further validate result noteworthiness. Integrative analysis of genetic and eQTL (expression quantitative trait locus) data was coupled with network and pathway analysis to explore the hypothesis that specific cell functions are involved in sarcoma predisposition.

Results

We retrieved 90 eligible studies comprising 47,796 subjects (cases: 14,358, 30%) and investigating 1,126 polymorphisms involving 320 distinct genes. Meta-analysis identified 55 single nucleotide polymorphisms (SNPs) significantly associated with disease risk with a high (N=9), moderate (N=38) and low (N=8) level of evidence, findings being classified as noteworthy basically only when the level of evidence was high. The estimated joint population attributable risk for three independent SNPs (rs11599754 of ZNF365/EGR2, rs231775 of CTLA4, and rs454006 of PRKCG) was 37.2%. We also identified 53 SNPs significantly associated with sarcoma risk based on single studies.Pathway analysis enabled us to propose that sarcoma predisposition might be linked especially to germline variation of genes whose products are involved in the function of the DNA repair machinery.

Conclusions

We built the first knowledgebase on the evidence linking DNA variation to sarcomas susceptibility, which can be used to generate mechanistic hypotheses and inform future studies in this field of oncology.

Candidate germline polymorphisms of genes belonging to the pathways of four drugs used in osteosarcoma standard chemotherapy associated with risk, survival and toxicity in non-metastatic high-grade osteosarcoma

This study aimed to identify associations between germline polymorphisms and risk of high-grade osteosarcoma (HGOS) development, event-free survival (EFS) and toxicity in HGOS patients treated with neo-adjuvant chemotherapy and surgery.

Germline polymorphisms of 31 genes known to be relevant for transport or metabolism of all four drugs used in HGOS chemotherapy (methotrexate, doxorubicin, cisplatin and ifosfamide) were genotyped in 196 patients with HGOS and in 470 healthy age and gender-matched controls. Of these 196 HGOS patients, a homogeneously treated group of 126 patients was considered for survival analyses (survival cohort). For 57 of these, treatment-related toxicity data were available (toxicity cohort).

Eleven polymorphisms were associated with increased risk of developing HGOS (p < 0.05). The distribution of polymorphisms in patients was characterized by a higher Shannon entropy. In the survival cohort (n = 126, median follow-up = 126 months), genotypes of ABCC2_1249A/G, GGH_452T/C, TP53_IVS2+38G/C and CYP2B6*6 were associated with EFS (p < 0.05). In the toxicity cohort (n = 57), genotypes of ABCB1_1236T/C, ABCC2_1249A/G, ABCC2_3972A/G, ERCC1_8092T/G, XPD_23591A/G, XRCC3_18067T/C, MTHFR_1298A/C and GGH_16T/C were associated with elevated risk for toxicity development (p < 0.05).

The results obtained in this retrospective study indicate that the aforementioned germline polymorphisms significantly impact on the risk of HGOS development, EFS and the occurrence of chemotherapy-related toxicity. These findings should be prospectively validated with the aim of optimizing and tailoring HGOS treatment in the near future.

Inhibition of NADPH oxidase 2 induces apoptosis in osteosarcoma: The role of reactive oxygen species in cell proliferation

Osteosarcomas (OS) are aggressive tumors that are characterized by dysregulated growth and resistance to apoptosis. Reactive oxygen species (ROS) are thought to be important signal transduction molecules in the regulation of cell growth. ROS-generating nicotinamide adenine dinucleotide phosphate oxidase (NOX) family enzymes have previously been suggested to be involved in neoplastic proliferation. To examine whether NOX-mediated generation of intracellular ROS confers anti-apoptotic activity, and thus a growth advantage, the current study first analyzed the mRNA expression of NOX family members by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) in five human OS cell lines. RT-PCR analysis revealed that NOX2 and NOX4 mRNAs were expressed in all the OS cell lines examined, whereas little or no NOX1 and NOX3 mRNAs were detected. By RT-qPCR, NOX2 mRNA expression levels were demonstrated to be higher than NOX4 mRNA expression levels. The viability of OS cells decreased in a dose-dependent manner with treatment of diphenylene iodonium (DPI), an inhibitor of flavoprotein-dependent oxidase. DPI treatment was observed to reduce intracellular ROS levels by ~50%, and increase the frequency of apoptosis by 30%. Notably, small interfering RNAs (siRNAs) targeting NOX2 significantly suppressed ROS generation; ROS depletion by DPI or NOX2 siRNAs induced apoptosis in OS cells. Together, the results of the present study indicate that NOX2-mediated ROS generation promotes cell survival and ROS depletion leads to apoptosis, thus highlighting the NOX2-ROS signaling pathway as a potential therapeutic target for OS treatment.

PARK2 inhibits osteosarcoma cell growth through the JAK2/STAT3/VEGF signaling pathway

Osteosarcoma (OS) is the most common primary malignant bone tumor mainly occurring in children and adolescents. In past decades, studies revealed that PARK2 was a vital tumor suppressor gene in many malignant solid tumors. However, the role of PARK2 in OS remains largely unclear. Therefore, we assessed PARK2 expression in OS tissue and adjacent non-tumor tissues by immunohistochemical (IHC) analysis, and evaluated PARK2 mRNA expression in OS cell lines by real-time PCR analysis. The HOS and U2OS cell lines were employed to establish a PARK2 overexpression model. Using this model, we investigated the potential role of PARK2 in OS and explored the underlying molecular mechanisms. Our study showed PARK2 was downregulated in OS tissue and cell lines, which was significantly associated with higher tumor stage (P < 0.05). Overexpression of PARK2 arrested the cell cycle, inhibited cell proliferation, migration, and invasion, induced cell apoptosis, and reduced tube formation in vitro. Moreover, overexpression of PARK2 significantly suppressed tumor growth and angiogenesis in vivo. Additionally, PARK2 negatively regulated OS development through the JAK2/STAT3/VEGF pathway. Our findings demonstrate that PARK2 is a tumor suppressor gene that may negatively affect OS growth and angiogenesis via partly inhibiting the JAK2/STAT3/VEGF signaling pathway.

Murine models of osteosarcoma: A piece of the translational puzzle

Osteosarcoma (OS) is the most common cancer of bone in children and young adults. Despite extensive research efforts, there has been no significant improvement in patient outcome for many years. An improved understanding of the biology of this cancer and how genes frequently mutated contribute to OS may help improve outcomes for patients. While our knowledge of the mutational burden of OS is approaching saturation, our understanding of how these mutations contribute to OS initiation and maintenance is less clear. Murine models of OS have now been demonstrated to be highly valid recapitulations of human OS. These models were originally based on the frequent disruption of p53 and Rb in familial OS syndromes, which are also common mutations in sporadic OS. They have been applied to significantly improve our understanding about the functions of recurrently mutated genes in disease. The murine models can be used as a platform for preclinical testing and identifying new therapeutic targets, in addition to testing the role of additional mutations in vivo. Most recently these models have begun to be used for discovery based approaches and screens, which hold significant promise in furthering our understanding of the genetic and therapeutic sensitivities of OS. In this review, we discuss the mouse models of OS that have been reported in the last 3-5 years and newly identified pathways from these studies. Finally, we discuss the preclinical utilization of the mouse models of OS for identifying and validating actionable targets to improve patient outcome.

Fibroblast activation protein in osteosarcoma cells promotes angiogenesis via AKT and ERK signaling pathways

Although it is established as a marker of cancer-associated fibroblasts, the expression of fibroblast activation protein (FAP) is not restricted to stromal cells; its expression in multiple types of tumor cell and its pro-tumor functions have been reported. However, the role of FAP in angiogenesis in osteosarcoma remains uncharacterized. In the present study, it was identified that the mRNA and protein expression levels of FAP and vascular endothelial growth factor-A (VEGF-A) corresponded to each other in MG63, U2-OS and HOS osteosarcoma cells. Subsequent to upregulating FAP in MG63 cells, VEGF-A mRNA and protein expression significantly increased; subsequent to downregulating FAP in U2-OS cells, VEGF-A mRNA and protein expression significantly declined. These changes in VEGF-A level were also detected in the cell supernatant with ELISA. Conditioned medium (CM) from MG63 cells overexpressing FAP promoted the phosphorylation of AKT and extracellular signal-regulated kinase (ERK) in human umbilical vein endothelial cells (HUVECs), as well as the proliferation rate. The CM from U2-OS cells with FAP knockdown inhibited the proliferation rate of HUVECs. The phosphorylation of AKT and ERK was increased in MG63 cells overexpressing FAP, but reduced in U2-OS cells with FAP knockdown. Furthermore, treatment with the AKT inhibitor LY294002 or the ERK inhibitor U0126 inhibited the upregulation of VEGF-A induced by FAP expression. Collectively, the results suggest that FAP expression in osteosarcoma cells promotes angiogenesis.

To Explore the Mechanism of the GRM4 Gene in Osteosarcoma by RNA Sequencing and Bioinformatics Approach

Background

Glutamate metabotropic receptor 4 (GRM4) has been correlated with the pathogenesis of osteosarcoma. The objective of this study was to explore the underlying molecular mechanism of GRM4 in osteosarcoma.

Material/Methods

The expression levels of GRM4 in four human osteosarcoma cell lines and hFOB1.19 cells were examined by real-time quantitative PCR (RT-qPCR). The U2OS cells of the highest GRM4 expression were transfected with lentivirus-mediated small interfering RNA (siRNA). The differentially expressed genes (DEGs) after GRM4 gene silencing were screened through RNA sequencing, and analyzed by bioinformatics. Additionally, the transcription factors (TFs) targeting GRM4 were predicted and the downstream protein-protein interaction (PPI) network was constructed using the bioinformatics approach.

Results

A total of 51 significant DEGs were obtained, including 14 upregulated and 37 downregulated DEGs. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of the DEGs indicated that four significant enrichment pathways were obtained. A total of six TFs that could be involved in the transcriptional regulation of GRM4 were detected. The results showed that 182 genes in the PPI network were significantly enriched in 14 pathways. The chemokines and chemokine receptors were found to be significantly enriched in three pathways.

Conclusions

The DEGs in the four significant enrichment pathways might participate in the development and progression of osteosarcoma through GRM4. The results revealed that EGR1 and CTCF are probably involved in the transcriptional regulation of GRM4, which participates in the progress of osteosarcoma by interacting with chemokines and their receptors.

A compendium and functional characterization of mammalian genes involved in adaptation to Arctic or Antarctic environments

Background

Many mammals are well adapted to surviving in extremely cold environments. These species have likely accumulated genetic changes that help them efficiently cope with low temperatures. It is not known whether the same genes related to cold adaptation in one species would be under selection in another species. The aims of this study therefore were: to create a compendium of mammalian genes related to adaptations to a low temperature environment; to identify genes related to cold tolerance that have been subjected to independent positive selection in several species; to determine promising candidate genes/pathways/organs for further empirical research on cold adaptation in mammals.

Results

After a search for publications containing keywords: “whole genome”, “transcriptome or exome sequencing data”, and “genome-wide genotyping array data” authors looked for information related to genetic signatures ascribable to positive selection in Arctic or Antarctic mammalian species. Publications related to Human, Arctic fox, Yakut horse, Mammoth, Polar bear, and Minke whale were chosen. The compendium of genes that potentially underwent positive selection in >1 of these six species consisted of 416 genes. Twelve of them showed traces of positive selection in three species. Gene ontology term enrichment analysis of 416 genes from the compendium has revealed 13 terms relevant to the scope of this study. We found that enriched terms were relevant to three major groups: terms associated with collagen proteins and the extracellular matrix; terms associated with the anatomy and physiology of cilium; terms associated with docking. We further revealed that genes from compendium were over-represented in the lists of genes expressed in the lung and liver.

Conclusions

A compendium combining mammalian genes involved in adaptation to cold environment was designed, based on the intersection of positively selected genes from six Arctic and Antarctic species. The compendium contained 416 genes that have been positively selected in at least two species. However, we did not reveal any positively selected genes that would be related to cold adaptation in all species from our list. But, our work points to several strong candidate genes involved in mechanisms and biochemical pathways related to cold adaptation response in different species.

Electronic supplementary material

The online version of this article (10.1186/s12863-017-0580-9) contains supplementary material, which is available to authorized users.

Genetic Polymorphisms of Insulin-Like Growth Factor 1 Are Associated with Osteosarcoma Risk and Prognosis

Background

Insulin-like growth factor 1 (IGF-1) gene plays an important role in bone and soft tumors. IGF-1 gene polymorphisms have been revealed to be correlated with the carcinogenesis and progression of solid malignancies. We therefore hypothesized that IGF-1 genetic polymorphisms might be associated with the risks and outcomes of osteosarcomas in Chinese individuals.

Material/Methods

This study included 173 conventional osteosarcoma individuals and 175 tumor-free controls. Five single nucleotide polymorphisms (SNPs) of IGF-1 (rs6214, rs6218, rs35767, rs5742612, and rs5742714) were genotyped. DNA was extracted from peripheral blood and analyzed for SNP genotyping using PCR.

Results

We found that rs6218 had a predictive role for the susceptibility and progression of osteosarcoma. The presence of TC and CC genotypes of rs6218 indicated higher risk of osteosarcoma. In addition, rs6218 TC and CC genotypes were discovered to be associated with later stage and elevated risk of osteosarcoma metastasis.

Conclusions

IGF-1 polymorphisms are potential prognostic predictors of osteosarcoma susceptibility and outcomes.

Comparative review of human and canine osteosarcoma: morphology, epidemiology, prognosis, treatment and genetics

Osteosarcoma (OSA) is a rare cancer in people. However OSA incidence rates in dogs are 27 times higher than in people. Prognosis in both species is relatively poor, with 5 year OSA survival rates in people not having improved in decades. For dogs, 1 year survival rates are only around ~ 45%. Improved and novel treatment regimens are urgently required to improve survival in both humans and dogs with OSA. Utilising information from genetic studies could assist in this in both species, with the higher incidence rates in dogs contributing to the dog population being a good model of human disease. This review compares the clinical characteristics, gross morphology and histopathology, aetiology, epidemiology, and genetics of canine and human OSA. Finally, the current position of canine OSA genetic research is discussed and areas for additional work within the canine population are identified.

Integrative genome analysis of somatic p53 mutant osteosarcomas identifies Ets2-dependent regulation of small nucleolar RNAs by mutant p53 protein

Pourebrahim et al. developed a traceable somatic osteosarcoma mouse model that is initiated with either a single p53 mutation (p53R172H) or p53 loss in osteoblasts. They identified a cluster of Ets2-dependent small nucleolar RNAs (snoRNAs) that are highly up-regulated in p53 mutant tumors.

TP53 is the most frequently mutated gene in human cancer. Many mutant p53 proteins exert oncogenic gain-of-function (GOF) properties that contribute to metastasis, but the mechanisms mediating these functions remain poorly defined in vivo. To elucidate how mutant p53 GOF drives metastasis, we developed a traceable somatic osteosarcoma mouse model that is initiated with either a single p53 mutation (p53R172H) or p53 loss in osteoblasts. Our study confirmed that p53 mutant mice developed osteosarcomas with increased metastasis as compared with p53-null mice. Comprehensive transcriptome RNA sequencing (RNA-seq) analysis of 16 tumors identified a cluster of small nucleolar RNAs (snoRNAs) that are highly up-regulated in p53 mutant tumors. Regulatory element analysis of these deregulated snoRNA genes identified strong enrichment of a common Ets2 transcription factor-binding site. Homozygous deletion of Ets2 in p53 mutant mice resulted in strong down-regulation of snoRNAs and reversed the prometastatic phenotype of mutant p53 but had no effect on osteosarcoma development, which remained 100% penetrant. In summary, our studies identify Ets2 inhibition as a potential therapeutic vulnerability in p53 mutant osteosarcomas.

[Pathogenesis and genetics of osteosarcoma : Current concepts and developments]

Osteosarcomas are genetically complex tumours for which the cell of origin and the molecular pathogenesis are still poorly understood. Despite intensive multimodal treatment protocols only two thirds of patients currently survive the disease which is at least partly due to the early occurring chromosomal instability resulting in marked inter- and intratumoral heterogeneity. This review article outlines the current state of osteosarcoma research with a particular focus on exome- and genome-wide sequencing analyses and potential impacts on new therapeutic opportunities.

Higher-than-expected population prevalence of potentially pathogenic germline TP53 variants in individuals unselected for cancer history

Li-Fraumeni syndrome (LFS) is an autosomal-dominant cancer predisposition disorder associated with pathogenic germline variants in TP53, with a high penetrance over an individual's lifetime. The actual population prevalence of pathogenic germline TP53 mutations is still unclear, most likely due to biased selection of cancer affected families. The aim of this study was to estimate the population prevalence of potentially pathogenic TP53 exonic variants in three sequencing databases, totaling 63,983 unrelated individuals. Potential pathogenicity was defined using an original algorithm combining bioinformatic prediction tools, suggested clinical significance, and functional data. We identified 34 different potentially pathogenic TP53 variants in 131 out of 63,983 individuals (0.2%). Twenty-eight (82%) of these variants fell within the DNA-binding domain of TP53, with an enrichment for specific variants that were not previously identified as LFS mutation hotspots, such as the p.R290H and p.N235S variants. Our findings reveal that the population prevalence of potentially pathogenic TP53 variants may be up to 10 times higher than previously estimated from family-based studies. These results point to the need for further studies aimed at evaluating cancer penetrance modifiers as well as the risk associated between cancer and rare TP53 variants.

Molecular genetics of osteosarcoma

Osteosarcoma is the predominant form of bone cancer, affecting mostly adolescents. Recent progress made in molecular genetic studies of osteosarcoma has changed our view on the cause of the disease and ongoing therapeutic approaches for patients. As we draw closer to gaining more complete catalogs of candidate cancer driver genes in common forms of cancer, the landscape of somatic mutations in osteosarcoma is emerging from its first phase. In this review, we summarize recent whole genome and/or whole exome genomic studies, and then put these findings in the context of genetic hallmarks of somatic mutations and mutational processes in human osteosarcoma. One of the lessons learned here is that the extent of somatic mutations and complexity of the osteosarcoma genome are similar to that of common forms of adult cancer. Thus, a much higher number of samples than those currently obtained are needed to complete the catalog of driver mutations in human osteosarcoma. In parallel, genetic studies in other species have revealed candidate driver genes and their roles in the genesis of osteosarcoma. This review also summarizes newly identified drivers in genetically engineered mouse models (GEMMs) and discusses our understanding of the impact of nature and number of drivers on tumor latency, subtypes, and metastatic potentials of osteosarcoma. It is becoming apparent that a synergistic team composed of three drivers (one 'first driver' and two 'synergistic drivers') may be required to generate an animal model that recapitulates aggressive osteosarcoma with a short latency. Finally, new cancer therapies are urgently needed to improve survival rate and quality of life for osteosarcoma patients. Several vulnerabilities in osteosarcoma are illustrated in this review to exemplify the opportunities for next generation molecularly targeted therapies. However, much work remains in order to complete our understanding of the somatic mutation basis of osteosarcoma, to develop reliable animal models of human disease, and to apply this information to guide new therapeutic approaches for reducing morbidity and mortality of this rare disease.

Identification of miRNA and genes involving in osteosarcoma by comprehensive analysis of microRNA and copy number variation data

The aim of the present study was to understand the molecular mechanisms of osteosarcoma by comprehensive analysis of microRNA (miRNA/miR) and copy number variation (CNV) microarray data. Microarray data (GSE65071 and GSE33153) were downloaded from the Gene Expression Omnibus. In GSE65071, differentially expressed miRNAs between the osteosarcoma and control groups were calculated by the Limma package. Target genes of differentially expressed miRNAs were identified by the starBase database. For GSE33153, PennCNV software was used to perform the copy number variation (CNV) analysis. Overlapping of the genes in CNV regions and the target genes of differentially expressed miRNAs were used to construct miRNA-gene regulatory network using the starBase database. A total of 149 differentially expressed miRNAs, including 13 downregulated and 136 upregulated, were identified. In the GSE33153 dataset, 987 CNV regions involving in 3,635 genes were identified. In total, 761 overlapping genes in 987 CNV regions and in the genes in 7,313 miRNA-gene pairs were obtained. miRNAs (hsa-miR-27a-3p, hsa-miR-124-3p, hsa-miR-9-5p, hsa-miR-182-5p, hsa-miR-26a-5p) and the genes [Fibroblast growth factor receptor substrate 2 (FRS2), coronin 1C (CORO1C), forkhead box P1 (FOXP1), cytoplasmic polyadenylation element binding protein 4 (CPEB4) and glucocorticoid induced 1 (GLCCI1)] with the highest degrees of association with osteosarcoma development were identified. Hsa-miR-27a-3p, hsa-miR-9-5p, hsa-miR-182-5p, FRS2, CORO1C, FOXP1 and CPEB4 may be involved in osteosarcoma pathogenesis, and development.

Germline and somatic genetics of osteosarcoma - connecting aetiology, biology and therapy

Clinical outcomes and treatment modalities for osteosarcoma, the most common primary cancer of bone, have changed very little over the past 30 years. The peak incidence of osteosarcoma occurs during the adolescent growth spurt, which suggests that bone growth and pubertal hormones are important in the aetiology of the disease. Tall stature, high birth weight and certain inherited cancer predisposition syndromes are well-described risk factors for osteosarcoma. Common genetic variants are also associated with osteosarcoma. The somatic genome of osteosarcoma is highly aneuploid, exhibits extensive intratumoural heterogeneity and has a higher mutation rate than most other paediatric cancers. Complex pathways related to bone growth and development and tumorigenesis are also important in osteosarcoma biology. In this Review, we discuss the contributions of germline and somatic genetics, tumour biology and animal models in improving our understanding of osteosarcoma aetiology, and their potential to identify novel therapeutic targets and thus improve the lives of patients with osteosarcoma.

Transcription Factor 21 (TCF21) rs12190287 Polymorphism is Associated with Osteosarcoma Risk and Outcomes in East Chinese Population

Background

The transcription factor 21 (TCF21) gene is believed to be a tumor suppressor gene. TCF21 gene polymorphisms were found to play a role in the tumorigenesis of some solid malignancies. We raised a hypothesis that genetic polymorphisms of TCF21 were correlated with risk and prognosis of osteosarcoma.

Material/Methods

We recruited 225 young osteosarcoma individuals and 250 cancer-free controls. Five tagging SNPs (TCF21 rs2327429 T>C, rs2327433 A>G, rs2327433 A>G, rs12190287 C>G, and rs4896011 T>A) were genotyped. Preserved DNA samples from blood underwent PCR analysis for genotyping.

Results

rs12190287 C>G is a good predictor of osteosarcoma risk and outcomes. The CG and GG genotypes of rs12190287 predict elevated risk of osteosarcoma. Besides, rs12190287 CG and GG genotypes are associated with Enneking stage and potential in forming metastasis of osteosarcoma.

Conclusions

Genetic polymorphisms of TCF21 are potentially predictive for osteosarcoma risk and outcomes.

Identification of Key Gene Modules in Human Osteosarcoma by Co-Expression Analysis Weighted Gene Co-Expression Network Analysis (WGCNA)

Osteosarcoma is the eighth-most common form of childhood cancer, comprising about 20% of all primary bone cancers. To date, systemic co-expression analysis for this cancer is still insufficient to explain the pathogenesis of poorly understood OC. The objective of this study was to construct a gene co-expression network to predict clusters of candidate genes involved in the pathogenesis of osteosarcoma. First, we contributed co-expression modules via weighted gene co-expression network analysis (WGCNA) and investigated the functional enrichment analysis of co-expression genes in terms of GO and KEGG. In result, seven co-expression modules were identified, containing 2,228 differentially expressed genes identified from the 22 human osteosarcoma samples. Subsequently, correlation study showed that the hub-genes between pair-wise modules displayed significant differences. Lastly, functional enrichment analysis of the co-expression modules showed that the module 5 enriched in progresses of immune response, antigen processing, and presentation. In conclusion, we identified essential genes in module 5 which were associated to human osteosarcoma. The key genes in our findings might provide the framework of co-expression gene modules of human osteosarcoma. Further, the functional analysis of these associated genes provides references to understand the mechanism of Osteosarcoma. J. Cell. Biochem. 118: 3953-3959, 2017. © 2017 Wiley Periodicals, Inc.

Expression of G Protein-coupled Receptor 56 Is an Unfavorable Prognostic Factor in Osteosarcoma Patients

G protein-coupled receptor 56 (GPR56) is an atypical G protein-coupled receptor, with the long extracellular N-terminus. GPR56 can trigger various downstream signaling responsible for cell survival, proliferation, adhesion, and migration. Expression of GPR56 is associated with cell malignant transformation and tumor cell metastasis in several carcinomas such as melanoma and glioma. Osteosarcoma is the most common malignant bone tumor in adolescents and young adults with high metastasis tendency. The overall survival of osteosarcoma is unsatisfied, partially due to the lacking of predictive markers for metastasis and overall prognosis. This study aimed at figuring out whether expression of the GPR56 was associated with clinicopathological features of osteosarcoma. Eighty-nine patients who received osteosarcoma operation between March 2004 and February 2011 in Linyi People's Hospital were recruited. Immunohistochemical staining (IHC) was carried out to identify the expression of GPR56 in those osteosarcoma tissues, and our cohort was divided into higher-expression group and lower-expression group according to the cut-off of IHC score. Expression of GPR56 in osteosarcoma tissues was correlated with the TNM stage and overall survival. Univariate and multivariate analysis showed that GPR56 could act as an independent prognosis factor for osteosarcoma. Western blot results demonstrated that GPR56-siRNA down-regulated the expression of GTP-RhoA and Ki67. GTP-RhoA participates in the cell migration process, while Ki67 plays important roles in cell proliferation, indicating GPR56 may function in tumor development. Correspondingly, we show that GPR56 regulates the proliferation and invasion capacity of osteosarcoma cells. Our study has revealed the prognostic value of GPR56 expression in osteosarcoma.

Enhanced Stim1 expression is associated with acquired chemo-resistance of cisplatin in osteosarcoma cells

Osteosarcoma is the most common primary malignant bone tumor. Although cisplatin is the primary chemotherapy used in osteosarcoma treatment, the cisplatin resistance remains a big challenge for improving overall survival. The store-operated calcium (Ca²⁺) entry (SOCE) and its major mediator Stim1 have been shown to be implicated in a number of pathological processes typical for cancer. In this study, we showed that Stim1 expression was significantly increased in chemo-resistant osteosarcoma tissues compared with chemo-sensitivity tissues. Patients with Sitm1 expression exhibited poorer overall survival than Stim1-negative patients. Moreover, un-regulation of Stim1 expression and SOCE were also observed in cisplatin-resistant MG63/CDDP cells compared with their parental cells. Cisplatin treatment obviously reduced Stim1 expression and SOCE in cisplatin-sensitivity MG63 cells, but had no effects on MG63/CDDP cells. In addition, cisplatin resulted in a more pronounced increase of endoplasmic reticulum (ER) stress in MG63 cells than in their resistant variants, which was evidenced by the activation of molecular markers of ER stress, GRP78, CHOP and ATF4. Knockdown of Stim1 using siRNA remarkably enhanced cisplatin-induced apoptosis and ER stress in MG63/CDDP cells, thereby sensitizing cancer cells to cisplatin. On the other hand, overexpression of Stim1 markedly reversed apoptosis and ER stress following cisplatin treatment. Taken together, these results demonstrate that Stim1 as well as Ca²⁺ entry contributes cisplatin resistance via inhibition of ER stress-mediated apoptosis, and provide important clues to the mechanisms involved in cisplatin resistance for osteosarcoma treatment. Stim1 represents as a target of cisplatin and blockade of Stim1-mediated Ca²⁺ entry may be a useful strategy to improve the efficacy of cisplatin to treat osteosarcoma.

Neuronal Activity in Ontogeny and Oncology

The nervous system plays a central role in regulating the stem cell niche in many organs, and thereby pivotally modulates development, homeostasis, and plasticity. A similarly powerful role for neural regulation of the cancer microenvironment is emerging. Neurons promote the growth of cancers of the brain, skin, prostate, pancreas, and stomach. Parallel mechanisms shared in development and cancer suggest that neural modulation of the tumor microenvironment may prove a universal theme, although the mechanistic details of such modulation remain to be discovered for many malignancies. We review here what is known about the influences of active neurons on stem cell and cancer microenvironments across a broad range of tissues, and we discuss emerging principles of neural regulation of development and cancer.

Advances in the Treatment of Pediatric Bone Sarcomas

Bone tumors make up a significant portion of noncentral nervous system solid tumor diagnoses in pediatric oncology patients. Ewing sarcoma and osteosarcoma, both with distinct clinical and pathologic features, are the two most commonly encountered bone cancers in pediatrics. Although mutations in the germline have classically been more associated with osteosarcoma, there is recent evidence germline alterations in patients with Ewing sarcoma also play a significant role in pathogenesis. Treatment advances in this patient population have lagged behind that of other pediatric malignancies, particularly targeted interventions directed at the biologic underpinnings of disease. Recent advances in biologic and genomic understanding of these two cancers has expanded the potential for therapeutic advancement and prevention. In Ewing sarcoma, directed focus on inhibition of EWSR1-FLI1 and its effectors has produced promising results. In osteosarcoma, instead of a concentrated focus on one particular change, largely due to tumor heterogeneity, a more diversified approach has been adopted including investigations of growth factors inhibitors, signaling pathway inhibitors, and immune modulation. Continuing recently made treatment advances relies on clinical trial design and enrollment. Clinical trials should include incorporation of biological findings; specifically, for Ewing sarcoma, assessment of alternative fusions and, for osteosarcoma, stratification utilizing biomarkers. Expanded cancer genomics knowledge, particularly with solid tumors, as it relates to heritability and incorporation of family history has led to early identification of patients with cancer predisposition. In these patients through application of cost-effective evidence-based screening techniques the ultimate goal of cancer prevention is becoming a realization.

Advances in the Treatment of Pediatric Bone Sarcomas

Bone tumors make up a significant portion of noncentral nervous system solid tumor diagnoses in pediatric oncology patients. Ewing sarcoma and osteosarcoma, both with distinct clinical and pathologic features, are the two most commonly encountered bone cancers in pediatrics. Although mutations in the germline have classically been more associated with osteosarcoma, there is recent evidence germline alterations in patients with Ewing sarcoma also play a significant role in pathogenesis. Treatment advances in this patient population have lagged behind that of other pediatric malignancies, particularly targeted interventions directed at the biologic underpinnings of disease. Recent advances in biologic and genomic understanding of these two cancers has expanded the potential for therapeutic advancement and prevention. In Ewing sarcoma, directed focus on inhibition of EWSR1-FLI1 and its effectors has produced promising results. In osteosarcoma, instead of a concentrated focus on one particular change, largely due to tumor heterogeneity, a more diversified approach has been adopted including investigations of growth factors inhibitors, signaling pathway inhibitors, and immune modulation. Continuing recently made treatment advances relies on clinical trial design and enrollment. Clinical trials should include incorporation of biological findings; specifically, for Ewing sarcoma, assessment of alternative fusions and, for osteosarcoma, stratification utilizing biomarkers. Expanded cancer genomics knowledge, particularly with solid tumors, as it relates to heritability and incorporation of family history has led to early identification of patients with cancer predisposition. In these patients through application of cost-effective evidence-based screening techniques the ultimate goal of cancer prevention is becoming a realization.

Osteosarcoma Overview

Osteosarcoma (OS) is the most common primary malignancy of bone and patients with metastatic disease or recurrences continue to have very poor outcomes. Unfortunately, little prognostic improvement has been generated from the last 20 years of research and a new perspective is warranted. OS is extremely heterogeneous in both its origins and manifestations. Although multiple associations have been made between the development of osteosarcoma and race, gender, age, various genomic alterations, and exposure situations among others, the etiology remains unclear and controversial. Noninvasive diagnostic methods include serum markers like alkaline phosphatase and a growing variety of imaging techniques including X-ray, computed tomography, magnetic resonance imaging, and positron emission as well as combinations thereof. Still, biopsy and microscopic examination are required to confirm the diagnosis and carry additional prognostic implications such as subtype classification and histological response to neoadjuvant chemotherapy. The current standard of care combines surgical and chemotherapeutic techniques, with a multitude of experimental biologics and small molecules currently in development and some in clinical trial phases. In this review, in addition to summarizing the current understanding of OS etiology, diagnostic methods, and the current standard of care, our group describes various experimental therapeutics and provides evidence to encourage a potential paradigm shift toward the introduction of immunomodulation, which may offer a more comprehensive approach to battling cancer pleomorphism.

Genome-wide RNAi screening identifies TMIGD3 isoform1 as a suppressor of NF-κB and osteosarcoma progression

The ability of cancer cells to survive and grow in anchorage- and serum-independent conditions is well correlated with their aggressiveness. Here, using a human whole-genome shRNA library, we identify TMIGD3 isoform1 (i1) as a factor that suppresses this ability in osteosarcoma (OS) cells, mainly by inhibiting NF-κB activity. Knockdown of TMIGD3 increases proliferation, tumour formation and metastasis of OS cells. Overexpression of TMIGD3 isoform1 (i1), but not isoform3 (i3) which shares a common C-terminal region, suppresses these malignant properties. Adenosine A3 receptor (A3AR) having an identical N-terminal region shows similar biological profiles to TMIGD3 i1. Protein expression of TMIGD3 and A3AR is lower in human OS tissues than normal tissues. Mechanistically, TMIGD3 i1 and A3AR commonly inhibit the PKA−Akt−NF-κB axis. However, TMIGD3 i1 only partially rescues phenotypes induced by A3AR knockdown, suggesting the presence of distinct pathways. Our findings reveal an unappreciated role for TMIGD3 i1 as a suppressor of NF-κB activity and OS progression.

The ability of cancer cells to survive in anchorage-independent conditions correlates with cancer aggressiveness. Here, by screening a human whole-genome shRNA library for the ability of osteosarcoma cells to form spheres in vitro, the authors identify a role for TMIGD3 isoform 1 in suppressing the metastatic potential of osteosarcoma.

Ras-Association Domain Family 1 Isoform A (RASSF1A) Gene Polymorphism rs1989839 is Associated with Risk and Metastatic Potential of Osteosarcoma in Young Chinese Individuals: A Multi-Center, Case-Control Study

Background

The ras-association domain family 1 isoform A (RASSF1A) gene serves as a bona fide tumor suppressor gene. The polymorphisms in RASSF1A were previously reported to be associated with the risk of solid malignant tumors. We hypothesized herein that RASSF1A gene polymorphisms are involved in the risk and prognosis of osteosarcoma (OS).

Material/Methods

We recruited 279 young OS cases and 286 tumor-free controls from the east Chinese population. Five tagSNPs of RASSF1A gene (rs2236947A/C, rs2073497A/C, rs1989839C/T, rs72932987C/T, and rs4688728G/T) were genotyped. DNA was isolated from blood samples and then underwent PCR analysis for genotyping.

Results

rs1989839C/T is an important predictor of osteosarcoma risk and outcome. The CT genotype of rs1989839 is highly related to elevated risk of osteosarcoma. Furthermore, rs1989839C/T is also associated with the Enneking stage of osteosarcoma and risk of lung metastasis. One of the other 4 SNPs, rs2236947A/C, shows a borderline significance in predicting osteosarcoma risk.

Conclusions

Our study is the first to prove that RASSF1A gene polymorphisms may potentially be predictive for osteosarcoma risk and prognosis.

Potential Intervention Targets in Utero and Early Life for Prevention of Hormone Related Cancers

Hormone-related cancers have long been thought to be sensitive to exposures during key periods of sexual development, as shown by the vulnerability to such cancers of women exposed to diethylstilbestrol in utero. In addition to evidence from human studies, animal studies using new techniques, such as gene knockout models, suggest that an increasing number of cancers may be hormonally related, including liver, lung, and bladder cancer. Greater understanding of sexual development has also revealed the "mini-puberty" of early infancy as a key period when some sex hormones reach levels similar to those at puberty. Factors driving sex hormones in utero and early infancy have not been systematically identified as potential targets of intervention for cancer prevention. On the basis of sex hormone pathways, we identify common potentially modifiable drivers of sex hormones, including but not limited to factors such as obesity, alcohol, and possibly nitric oxide. We review the evidence for effects of modifiable drivers of sex hormones during the prenatal period and early infancy, including measured hormones as well as proxies, such as the second-to-fourth digit length ratio. We summarize the gaps in the evidence needed to identify new potential targets of early life intervention for lifelong cancer prevention.

Review of Osteosarcoma and Current Management

Osteosarcoma is the most common primary malignancy of bone in children and young adults. This tumor has a very heterogeneous genetic profile and lacks any consistent unifying event that leads to the pathogenesis of osteosarcoma. In this review, some of the important genetic events involved in osteosarcoma will be highlighted. Additionally, the clinical diagnosis of osteosarcoma will be discussed, as well as contemporary chemotherapeutic and surgical management of this tumor. Finally, the review will discuss some of the novel approaches to treating this disease.

Association of interleukin 16 gene polymorphisms and plasma IL16 level with osteosarcoma risk

Interleukin (IL) 16 plays a key role in inflammatory diseases as well as in tumorigenesis of osteosarcoma (OS). The aim of this study was to investigate the association of IL16 polymorphisms and plasma IL16 level with OS risk in a Chinese population. We genotyped IL16 rs4778889, rs11556218, and rs4072111 in 358 patients with OS and 402 controls using a polymerase chain reaction-restriction fragment length polymorphism assay. Plasma IL16 level was measured by enzyme-linked immunosorbent assay. Rs11556218 was associated with an increased risk of OS in heterozygote comparison (adjusted OR = 1.65, 95% CI, 1.23–2.21, P < 0.001), dominant model (adjusted OR = 1.66, 95% CI, 1.24–2.21, P < 0.001), and allele comparison (adjusted OR = 1.44, 95% CI, 1.14–1.81, P = 0.002). Moreover, rs11556218 TG/GG genotypes were associated with higher levels of IL16 as compared to TT genotype (P = 0.03). However, no significant association of rs4778889 and rs4072111 and OS was found. These findings suggest that rs11556218 TG/GG genotypes may be associated with increased susceptibility to OS, probably by increasing the production of IL16 level.

A systematic review and meta-analysis of MDM2 polymorphisms in osteosarcoma susceptibility

Two polymorphisms in the murine double minute 2 (MDM2) gene (rs1690916 and rs2279744) have been associated with the risk of osteosarcoma (OS). When we analyzed these two polymorphisms in two new independents cohorts (Spanish and Slovenian), we found no association. In order to clarify this, we conducted a meta-analysis including six populations, with a total of 246 OS patients and 1,760 controls for rs1690916; and 433 OS patients and 1,959 controls for rs2279744. Pooled odds ratio risks and corresponding 95% CI were estimated to assess the possible associations. Our results showed that these two polymorphisms were not associated with the susceptibility of OS under any genetic model studied. In conclusion, the present meta-analysis indicates that MDM2 rs1690916 and rs2279744 cannot be considered as genetic risk factors for OS susceptibility in the different populations. Therefore, the influence of these two polymorphisms on the risk of OS may be less important than previously suggested. Future studies are needed to confirm these results.

RANKL blockade prevents and treats aggressive osteosarcomas

Osteosarcoma (OS) is the most common primary bone cancer, which occurs primarily in children and adolescents, severely affecting survivors' quality of life. Despite its chemosensitivity and treatment advances, long-term survival rates for OS patients have stagnated over the last 20 years. Thus, it is necessary to develop new molecularly targeted therapies for this metastatic bone cancer. Mutations in TP53 and RB are linked to OS predisposition and to the evolution of spontaneous OS. We established receptor activator of nuclear factor κB ligand (RANKL) as a therapeutic target for suppression and prevention of OS. Combined conditional osteoblast-specific deletions of Rb, p53, and the protein kinase A (PKA) regulatory subunit Prkar1α genes in genetically engineered mouse models (GEMMs) generate aggressive osteosarcomas, characterized by PKA, RANKL, and osteoclast hyperactivity. Whole-body Rankl deletion completely abrogates tumorigenesis. Although osteoblastic Rank deletion has little effect, osteoclastic Rank deletion delays tumorigenesis and prolongs life span. The latter is associated with inactivation of osteoclastogenesis and up-regulation of the tumor suppressor phosphatase and tensin homolog (PTEN). Further, we use these GEMMs as preclinical platforms to show that RANKL blockade with RANK-Fc arrests tumor progression and improves survival and also inhibits lung metastasis. Moreover, preemptive administration of RANK-Fc completely prevents tumorigenesis in mice highly predisposed to this aggressive cancer. Denosumab, a fully human monoclonal antibody against RANKL, is currently used to treat patients with osteoporosis or bone metastases. Our studies provide a strong rationale to consider RANKL blockade for the treatment and prevention of aggressive RANKL-overexpressing OS in humans.

A novel TP53-KPNA3 translocation defines a de novo treatment-resistant clone in osteosarcoma

Osteosarcoma is the most common primary bone cancer. It can be cured by aggressive surgery and chemotherapy, but outcomes for metastatic or chemoresistant disease remain dismal. Cancer sequencing studies have shown that the p53 pathway is dysregulated in nearly every case, often by translocation; however, no studies of osteosarcoma evolution or intratumor heterogeneity have been done to date. We studied a patient with chemoresistant, metastatic disease over the course of 3 years. We performed exome sequencing on germline DNA and DNA collected from tumor at three separate time points. We compared variant calls and variant allele frequencies between different samples. We identified subclonal mutations in several different genes in the primary tumor sample and found that one particular subclone dominated subsequent tumor samples at relapse. This clone was marked by a novel TP53-KPNA3 translocation and loss of the opposite-strand wild-type TP53 allele. Future research must focus on the functional significance of such clones and strategies to eliminate them.

Deciphering signaling networks in osteosarcoma pathobiology

Osteosarcoma is the most frequent type of primary bone tumors among children and adolescents. During the past years, little progress has been made regarding prognosis of osteosarcoma patients, especially for those with metastatic disease. Genomic instability and gene alterations are common, but current data do not reveal a consistent and repeatable pattern of osteosarcoma development, thus paralleling the tumor's high heterogeneity. Critical signal transduction pathways have been implicated in osteosarcoma pathobiology and are being evaluated as therapeutic targets, including receptor activator for nuclear factor-κB (RANK), Wnt, Notch, phosphatidylinositol 3-kinase/Akt/mammalian target of rapamycin, and mechanotransduction pathways. Herein, we recapitulate and discuss recent advances in the context of molecular mechanisms and signaling networks that contribute to osteosarcoma progression and metastasis, towards patient-tailored and novel-targeted treatments.

Comparative oncology: what dogs and other species can teach us about humans with cancer

Over 1.66 million humans (approx. 500/100,000 population rate) and over 4.2 million dogs (approx. 5300/100,000 population rate) are diagnosed with cancer annually in the USA. The interdisciplinary field of comparative oncology offers a unique and strong opportunity to learn more about universal cancer risk and development through epidemiology, genetic and genomic investigations. Working across species, researchers from human and veterinary medicine can combine scientific findings to understand more quickly the origins of cancer and translate these findings to novel therapies to benefit both human and animals. This review begins with the genetic origins of canines and their advantage in cancer research. We next focus on recent findings in comparative oncology related to inherited, or genetic, risk for tumour development. We then detail the somatic, or genomic, changes within tumours and the similarities between species. The shared cancers between humans and dogs that we discuss include sarcoma (osteosarcoma, soft tissue sarcoma, histiocytic sarcoma, hemangiosarcoma), haematological malignancies (lymphoma, leukaemia), bladder cancer, intracranial neoplasms (meningioma, glioma) and melanoma. Tumour risk in other animal species is also briefly discussed. As the field of genomics advances, we predict that comparative oncology will continue to benefit both humans and the animals that live among us.

Genetic factors conferring metastasis in osteosarcoma

Osteosarcoma (OS) is a deadly bone malignancy affecting mostly children and adolescents. OS has outstandingly complex genetic alterations likely due to p53-independent genomic instability. Based on analysis of recent published research we claim existence of various genetic mechanisms of osteosarcomagenesis conferring great variability to different OS properties including metastatic potential. We also propose a model explaining how diverse genetic mechanisms occur and providing a framework for future research. P53-independent preexisting genomic instability, which precedes and frequently causes TP53 genetic alterations, is central in our model. In addition, our analyses reveal a possible cooperation between aberrantly activated HIF-1α and AP-1 genetic pathways in OS metastasis. We also review the involvement of noncoding RNA genes in OS metastasis.

Activation of PTHrP-cAMP-CREB1 signaling following p53 loss is essential for osteosarcoma initiation and maintenance

Mutations in the P53 pathway are a hallmark of human cancer. The identification of pathways upon which p53-deficient cells depend could reveal therapeutic targets that may spare normal cells with intact p53. In contrast to P53 point mutations in other cancer, complete loss of P53 is a frequent event in osteosarcoma (OS), the most common cancer of bone. The consequences of p53 loss for osteoblastic cells and OS development are poorly understood. Here we use murine OS models to demonstrate that elevated Pthlh (Pthrp), cAMP levels and signalling via CREB1 are characteristic of both p53-deficient osteoblasts and OS. Normal osteoblasts survive depletion of both PTHrP and CREB1. In contrast, p53-deficient osteoblasts and OS depend upon continuous activation of this pathway and undergo proliferation arrest and apoptosis in the absence of PTHrP or CREB1. Our results identify the PTHrP-cAMP-CREB1 axis as an attractive pathway for therapeutic inhibition in OS.

DOI:http://dx.doi.org/10.7554/eLife.13446.001

Bone cancer (osteosarcoma) is caused by mutations in certain genes, which results in cells growing and dividing uncontrollably. In particular, a gene that produces a protein called P53 in humans is lost in all bone cancers. However, we don’t understand what happens to the bone cells when they lose P53. Although a number of studies have identified several molecular pathways that are changed in bone cancers – such as the cyclic AMP (cAMP) pathway – how these interact to cause a cancer is not well understood.

Walia et al. compared bone-forming cells from normal mice with cells from mutant mice from which the gene that produces the mouse p53 protein could be removed. This revealed that the loss of p53 causes these cells to grow faster. The activity of the cAMP pathway also increases in p53-deficient cells. Further investigation revealed that the cells grow faster only if they are able to activate the cAMP pathway, and that this pathway needs to stay active for bone cancer cells to grow and survive. This suggests that inhibiting this pathway could present a new way to treat bone cancer.

Walia et al. confirmed several of their findings in human cells. Future studies will now investigate how the loss of the P53 protein in humans activates the cAMP pathway, which will be important for understanding how this cancer forms. It will also be worthwhile to begin testing ways to block this pathway to determine whether it is a useful target for therapies.

DOI:http://dx.doi.org/10.7554/eLife.13446.002

Current state of pediatric sarcoma biology and opportunities for future discovery: A report from the sarcoma translational research workshop

Sarcomas are a rare subgroup of pediatric cancers comprised of a variety of bone and soft-tissue tumors. While significant advances have been made in improving outcomes of patients with localized pediatric sarcomas since the addition of systemic chemotherapy to local control many decades ago, outcomes for patients with metastatic and relapsed sarcoma remain poor with few novel therapeutics identified to date. With the advent of new technologies to study cancer genomes, transcriptomes and epigenomes, our understanding of sarcoma biology has improved tremendously in a relatively short period of time. However, much remains to be accomplished in this arena especially with regard to translating all of this new knowledge to the bedside. To this end, a meeting was convened in Philadelphia, PA, on April 18, 2015 sponsored by the QuadW foundation, Children's Oncology Group and CureSearch for Children's Cancer that brought together sarcoma clinicians and scientists from North America to review the current state of pediatric sarcoma biology and ongoing/planned genomics based clinical trials in an effort to identify and bridge knowledge gaps that continue to exist at present. At the conclusion of the workshop, three key objectives that would significantly further our understanding of sarcoma were identified and a proposal was put forward to develop an all-encompassing pediatric sarcoma biology protocol that would address these specific needs. This review summarizes the proceedings of the workshop.

Association of Somatic Mutations of ADAMTS Genes With Chemotherapy Sensitivity and Survival in High-Grade Serous Ovarian Carcinoma

IMPORTANCE

Chemotherapy response in the majority of patients with ovarian cancer remains unpredictable.

OBJECTIVE

To identify novel molecular markers for predicting chemotherapy response in patients with ovarian cancer.

DESIGN, SETTING, AND PARTICIPANTS

Observational study of genomics and clinical data of high-grade serous ovarian cancer cases with genomic and clinical data made public between 2009 and 2014 via the Cancer Genome Atlas project.

MAIN OUTCOMES AND MEASURES

Chemotherapy response (primary outcome) and overall survival (OS), progression-free survival (PFS), and platinum-free duration (secondary outcome).

RESULTS

In 512 patients with ovarian cancer with available whole-exome sequencing data, mutations from 8 members of the ADAMTS family (ADAMTS mutations) with an overall mutation rate of approximately 10.4% were associated with a significantly higher chemotherapy sensitivity (100% for ADAMTS-mutated vs 64% for ADAMTS wild-type cases; P < .001) and longer platinum-free duration (median platinum-free duration, 21.7 months for ADAMTS-mutated vs 10.1 months for ADAMTS wild-type cases; P = .001). Moreover, ADAMTS mutations were associated with significantly better OS (hazard ratio [HR], 0.54 [95% CI, 0.42-0.89]; P = .01 and median OS, 58.0 months for ADAMTS-mutated vs 41.3 months for ADAMTS wild-type cases) and PFS (HR, 0.42 [95% CI, 0.38-0.70]; P < .001 and median PFS, 31.8 for ADAMTS-mutated vs 15.3 months for ADAMTS wild-type cases). After adjustment by BRCA1 or BRCA2 mutation, surgical stage, residual tumor, and patient age, ADAMTS mutations were significantly associated with better OS (HR, 0.53 [95% CI, 0.32-0.87]; P = .01), PFS (HR, 0.40 [95% CI, 0.25-0.62]; P < .001), and platinum-free survival (HR, 0.45 [95% CI, 0.28-0.73]; P = .001). ADAMTS-mutated cases exhibited a distinct mutation spectrum and were significantly associated with tumors with a higher genome-wide mutation rate than ADAMTS wild-type cases across the whole exome (median mutation number per sample, 121 for ADAMTS-mutated vs 69 for ADAMTS wild-type cases; P < .001).

CONCLUSIONS AND RELEVANCE

ADAMTS mutations may contribute to outcomes in ovarian cancer cases without BRCA1 or BRCA2 mutations and may have important clinical implications.

Common genetic variants associated with telomere length confer risk for neuroblastoma and other childhood cancers

Aberrant telomere lengthening is an important feature of cancer cells in adults and children. In addition to somatic mutations, germline polymorphisms in telomere maintenance genes impact telomere length. Whether these telomere-associated polymorphisms affect risk of childhood malignancies remains largely unexplored. We collected genome-wide data from three groups with pediatric malignancies [neuroblastoma (N = 1516), acute lymphoblastic leukemia (ALL) (N = 958) and osteosarcoma (N = 660)] and three control populations (N = 6892). Using case-control comparisons, we analyzed eight single nucleotide polymorphisms (SNPs) in genes definitively associated with interindividual variation in leukocyte telomere length (LTL) in prior genome-wide association studies: ACYP2, TERC, NAF1, TERT, OBFC1, CTC1, ZNF208 and RTEL1 Six of these SNPs were associated (P < 0.05) with neuroblastoma risk, one with leukemia risk and one with osteosarcoma risk. The allele associated with longer LTL increased cancer risk for all these significantly associated SNPs. Using a weighted linear combination of the eight LTL-associated SNPs, we observed that neuroblastoma patients were predisposed to longer LTL than controls, with each standard deviation increase in genotypically estimated LTL associated with a 1.15-fold increased odds of neuroblastoma (95%CI = 1.09-1.22; P = 7.9×10(-7)). This effect was more pronounced in adolescent-onset neuroblastoma patients (OR = 1.46; 95%CI = 1.03-2.08). A one standard deviation increase in genotypically estimated LTL was more weakly associated with osteosarcoma risk (OR = 1.10; 95%CI = 1.01-1.19; P = 0.017) and leukemia risk (OR = 1.07; 95%CI = 1.00-1.14; P = 0.044), specifically for leukemia patients who relapsed (OR = 1.19; 95%CI = 1.01-1.40; P = 0.043). These results indicate that genetic predisposition to longer LTL is a newly identified risk factor for neuroblastoma and potentially for other cancers of childhood.