Perinatal factors associated with clinical presentation of osteosarcoma in children and adolescents

Genetically inferred birthweight, height, and puberty timing and risk of osteosarcoma

INTRODUCTION

Several studies have linked increased risk of osteosarcoma with tall stature, high birthweight, and early puberty, although evidence is inconsistent. We used genetic risk scores (GRS) based on established genetic loci for these traits and evaluated associations between genetically inferred birthweight, height, and puberty timing with osteosarcoma.

METHODS

Using genotype data from two genome-wide association studies, totaling 1039 cases and 2923 controls of European ancestry, association analyses were conducted using logistic regression for each study and meta-analyzed to estimate pooled odds ratios (ORs) and 95% confidence intervals (CIs). Subgroup analyses were conducted by case diagnosis age, metastasis status, tumor location, tumor histology, and presence of a known pathogenic variant in a cancer susceptibility gene.

RESULTS

Genetically inferred higher birthweight was associated with an increased risk of osteosarcoma (OR =1.59, 95% CI 1.07-2.38, P = 0.02). This association was strongest in cases without metastatic disease (OR =2.46, 95% CI 1.44-4.19, P = 9.5 ×10-04). Although there was no overall association between osteosarcoma and genetically inferred taller stature (OR=1.06, 95% CI 0.96-1.17, P = 0.28), the GRS for taller stature was associated with an increased risk of osteosarcoma in 154 cases with a known pathogenic cancer susceptibility gene variant (OR=1.29, 95% CI 1.03-1.63, P = 0.03). There were no significant associations between the GRS for puberty timing and osteosarcoma.

CONCLUSION

A genetic propensity to higher birthweight was associated with increased osteosarcoma risk, suggesting that shared genetic factors or biological pathways that affect birthweight may contribute to osteosarcoma pathogenesis.

The essential roles of m6A modification in osteogenesis and common bone diseases

N6-methyladenosine (m6A) is the most prevalent modification in the eukaryotic transcriptome and has a wide range of functions in coding and noncoding RNAs. It affects the fate of the modified RNA, including its stability, splicing, and translation, and plays an important role in post-transcriptional regulation. Bones play a key role in supporting and protecting muscles and other organs, facilitating the movement of the organism, ensuring blood production, etc. Bone diseases such as osteoarthritis, osteoporosis, and bone tumors are serious public health problems. The processes of bone development and osteogenic differentiation require the precise regulation of gene expression through epigenetic mechanisms including histone, DNA, and RNA modifications. As a reversible dynamic epigenetic mark, m6A modifications affect nearly every important biological process, cellular component, and molecular function, including skeletal development and homeostasis. In recent years, studies have shown that m6A modification is involved in osteogenesis and bone-related diseases. In this review, we summarized the proteins involved in RNA m6A modification and the latest progress in elucidating the regulatory role of m6A modification in bone formation and stem cell directional differentiation. We also discussed the pathological roles and potential molecular mechanisms of m6A modification in bone-related diseases like osteoporosis and osteosarcoma and suggested potential areas for new strategies that could be used to prevent or treat bone defects and bone diseases.

Assisted reproductive technology and association with childhood cancer subtypes

OBJECTIVES

To investigate the association between assisted reproductive technology (ART) use and childhood cancer subtype.

STUDY DESIGN

We deployed a cross-sectional survey of 1701 parents of children with cancer about their ART use, demographics, and gestational and perinatal factors. Multivariable logistic regression modeled the association between ART use, birthweight and multiple gestation status with childhood cancer, by subtype.

RESULTS

ART use was highest among children with osteosarcoma relative to children with other cancer types, and this association was statistically significant in multivariable models (OR = 4.4; 95% CI = 1.7-11.3; p = 0.0020). ART use was also elevated among children with hepatoblastoma, but this relationship appeared to be due to the strong associations between ART use and lower birthweight in our sample. No specific ART modality appeared to drive these associations. In univariate models, multiple gestation was associated with a 2.7-fold increased odds of hepatoblastoma (OR = 2.71; 95% CI = 1.14-6.42; p = 0.02) and a 1.6-fold increased odds of neuroblastoma (OR = 1.62; 95% CI = 1.03-2.54; p = 0.03), but these associations were not retained in multivariable models.

CONCLUSIONS

Associations between ART use and hepatoblastoma risk may be attributable to birthweight, a known hepatoblastoma risk factor. ART use may also be associated with osteosarcoma, independent of birthweight, an association not previously observed in studies limited to cancers diagnosed before adolescence. Evaluating long-term health outcomes in children conceived by ART, throughout adolescence and potentially into adulthood, appears warranted.

Cancer-Specific Survival after Limb Salvage versus Amputation in Children and Adolescents with Osteosarcoma: A Population-Based Analysis with Propensity Score Matching

Background

The study aims to identify whether osteosarcoma patients of children and young adults will benefit from a survival profit from the choice of the operation method.

Methods

The National Cancer Institute SEER database from 2000 to 2018 was selected for a retrospective analysis of 1630 children and young adults with a primary diagnosis of osteosarcoma, 1222 who underwent limb-preserving surgery, and 408 who underwent amputation. Confounders were controlled for by propensity score matching (PSM), cancer-specific survival (CSS) was analyzed using the Kaplan-Meier method, and univariate and multivariate Cox regression was used to analyze the factors influencing the prognosis of children and young osteosarcoma patients after surgery. A nomogram plot predicted 1-, 3-, and 5- survival rate in osteosarcoma. The model's accuracy was validated by the area under the ROC and calibration curves.

Results

After PSM, multifactor Cox regression analysis found AJCC Stage III-IV (CSS : HR = 5.26, 95% CI 1.95-14.18, p=0. 001; HR = 5.54, 95% CI 2.56-12.01, p < 0. 001. Limb salvage surgery (CSS : HR = 0.58, 95% CI 0.44-0.77, p < 0. 001) has independent impact factors for CSS prognosis. The survival curve before and after PSM showed that patients with osteosarcoma of children and young adults who underwent limb salvage surgery had a survival benefit compared with those who underwent amputation surgery. Gender, chemotherapy, histology, primary tumor site, stage, and surgical modality were modeled in a total of six variables in the nomogram. The model exhibited good predictive performance. The AUC were 0.823, 0.74, and 0.757 for training set at 1, 3, and 5 years, respectively. The AUC of validation set 0.666, 0.722, and 0.699 at 1, 3, and 5 years, respectively. The model also predicted CSS with good fidelity for both datasets. This model was significantly superior to the 8^th edition of the AJCC TNM staging system, with a better net benefit in predicting CSS in children and young adults with osteosarcoma.

Conclusion

Limb salvage surgery is an option for children and young adults with osteosarcoma and cancer-specific survival rates can be improved by receiving limb salvage surgery.

Emerging role of m6A modification in osteogenesis of stem cells

The differentiation of stem cells into osteoblasts is a key link in the treatment of bone defects and other orthopedic diseases. N6-methyladenosine (m6A) modification, an important post-transcriptional modification, is a methylation that occurs at the N6 site of RNA adenylate. The modification plays a regulatory role in the growth and development of biological individuals, the directional differentiation of stem cells and the occurrence of diseases. It is involved in various processes of the fate decision of stem cells. And it regulates the development and constant renewal of bone and keeps bone homeostasis by controlling and maintaining the balance between osteogenesis and adipogenesis. Meanwhile, it also affects the progress of orthopedic-associated diseases such as degenerative osteoporosis and bone tumor. In this review, we mainly summarize the new findings of three key molecules including Writers, Erasers and Readers which regulate m6A modification, and the emerging role of m6A modification in determining the fate and directed differentiation potential of stem cells, especially highlight the regulatory mechanism of osteogenic differentiation, the balance between osteogenesis and adipogenesis and the occurrence and development of bone-related diseases. It may provide some important ideas about finding new strategies to recover from bone defect and degenerative bone disease.

Machine Learning-Based Radiomics Nomogram With Dynamic Contrast-Enhanced MRI of the Osteosarcoma for Evaluation of Efficacy of Neoadjuvant Chemotherapy

OBJECTIVES

This study aims to evaluate the value of machine learning-based dynamic contrast-enhanced MRI (DCE-MRI) radiomics nomogram in prediction treatment response of neoadjuvant chemotherapy (NAC) in patients with osteosarcoma.

METHODS

A total of 102 patients with osteosarcoma and who underwent NAC were enrolled in this study. All patients received a DCE-MRI scan before NAC. The Response Evaluation Criteria in Solid Tumors was used as the standard to evaluate the NAC response with complete remission and partial remission in the effective group, stable disease, and progressive disease in the ineffective group. The following semi-quantitative parameters of DCE-MRI were calculated: early dynamic enhancement wash-in slope (Slope), time to peak (TTP), and enhancement rate (R). The acquired data is randomly divided into 70% for training and 30% for testing. Variance threshold, univariate feature selection, and least absolute shrinkage and selection operator were used to select the optimal features. Three classifiers (K-nearest neighbor, KNN; support vector machine, SVM; and logistic regression, LR) were implemented for model establishment. The performance of different classifiers and conventional semi-quantitative parameters was evaluated by confusion matrix and receiver operating characteristic curves. Furthermore, clinically relevant risk factors including age, tumor size and site, pathological fracture, and surgical staging were collected to evaluate their predictive values for the efficacy of NAC. The selected clinical features and imaging features were combined to establish the model and the nomogram, and then the predictive efficacy was evaluated.

RESULTS

The clinical relevance risk factor analysis demonstrates that only surgical stage was an independent predictor of NAC. A total of seven radiomic features were selected, and three machine learning models (KNN, SVM, and LR) were established based on such features. The prediction accuracy (ACC) of these three models was 0.89, 0.84, and 0.84, respectively. The area under the subject curve (AUC) of these three models was 0.86, 0.92, and 0.93, respectively. As for Slope, TTP, and R parameters, the prediction ACC was 0.91, 0.89, and 0.81, respectively, while the AUC was 0.87, 0.85, and 0.83, respectively. In both the training and testing sets, the ACC and AUC of the combined model were higher than those of the radiomics models (ACC = 0.91 and AUC = 0.95), which indicate an outstanding performance of our proposed model.

CONCLUSIONS

The radiomics nomogram demonstrates satisfactory predictive results for the treatment response of patients with osteosarcoma before NAC. This finding may provide a new decision basis to improve the treatment plan.

miR-96-5p is the tumor suppressor in osteosarcoma via targeting SYK

BACKGROUND

Osteosarcoma is a multiple malignant tumor in adolescents. MicroRNAs (MiRNAs) have been found to express abnormally in OS tissues and are considered as potential targets for OS prognosis and treatment.

METHODS

MiR-96-5p and SYK expression in clinical samples, osteoblast and OS cell lines were detected. The changes of cell proliferation, apoptosis, adhesion and metastasis of OS cells were detected by CCK-8, BrdU, caspase-3 activity and transwell assay. Dual luciferase report analysis and RNA pull-down were used to confirm binding relation of miR-96-5p and SYK.

RESULTS

MiR-96-5p was increased in OS tissue and cells. Moreover, miR-96-5p inhibits proliferation, adhesion and migration of HOS and Saos-2 cells, and promotes cell apoptosis. SYK has been identified to be targeted by miR-96-5p. Overexpressed SYK inhibits the suppressive impact of miR-96-5 on OS cells.

CONCLUSION

MiR-96-5p may function as an effective target in OS treatment.

Inhibiting proliferation and metastasis of osteosarcoma cells by downregulation of long non-coding RNA colon cancer-associated transcript 2 targeting microRNA-143

Osteosarcoma is a malignant bone tumor, which has a high incidence in children and adolescents. However, the pathogenesis of osteosarcoma remains unclear. Long noncoding RNA (lncRNA) is a new potential therapeutic target and diagnostic biomarker for osteosarcoma. Hence, the present study aimed to explore the effect of lncRNA colon cancer-associated transcript (CCAT2) on osteosarcoma and its potential underlying mechanisms. For this purpose, the proliferation of osteosarcoma cells was measured using the CCK-8 assay. The scratch-wound and cell invasion assays were used to determine the migration and invasion of osteosarcoma cells, respectively. LncRNA CCAT2 and microRNA (miR)-143 binding sites were identified by the dual-luciferase reporter assay. RNA and protein expression levels were detected by reverse-transcription quantitative PCR and western blotting, respectively. Downregulation of lncRNA CCAT2 inhibited the proliferation, migration, and invasion of osteosarcoma cells. The findings also revealed that miR-143 bound directly to lncRNA CCAT2. The expression of miR-143 was upregulated by the knockdown of lncRNA CCAT2. Downregulation of the FOS-like antigen 2 was also observed after knockdown of lncRNA CCAT2. The function of lncRNA CCAT2 in osteosarcoma cells was attenuated by co-transfection with anti-miR-143 oligodeoxyribonucleotide. In conclusion, downregulation of lncRNA CCAT2 inhibited the proliferation and metastasis of osteosarcoma cells by targeting miR-143. lncRNA CCAT2 was identified as a potential target for osteosarcoma treatment.

Development of Natural-Based Bone Cement for a Controlled Doxorubicin-Drug Release

Osteosarcoma (OS) accounts for 60% of all global bone cancer diagnoses. Intravenous administration of Doxorubicin Hydrochloride (DOXO) is the current form of OS treatment, however, systemic delivery has been linked to the onset of DOXO induced cardiomyopathy. Biomaterials including calcium phosphate cements (CPCs) and nanoparticles (NPs) have been tested as localized drug delivery scaffolds for OS cells. However, the tumor microenvironment is critical in cancer progression, with mesenchymal stem cells (MSCs) thought to promote OS metastasis and drug resistance. The extent of MSC assisted survival of OS cells in response to DOXO delivered by CPCs is unknown. In this study, we aimed at investigating the effect of DOXO release from a new formulation of calcium phosphate-based bone cement on the viability of OS cells cocultured with hMSC in vitro. NPs made of PLGA were loaded with DOXO and incorporated in the formulated bone cement to achieve local drug release. The inclusion of PLGA-DOXO NPs into CPCs was also proven to increase the levels of cytotoxicity of U2OS cells in mono- and coculture after 24 and 72 h. Our results demonstrate that a more effective localized DOXO delivery can be achieved via the use of CPCs loaded with PLGA-DOXO NPs compared to CPCs loaded with DOXO, by an observed reduction in metabolic activity of U2OS cells in indirect coculture with hMSCs. The presence of hMSCs offer a degree of DOXO resistance in U2OS cells cultured on PLGA-DOXO NP bone cements. The consideration of the tumor microenvironment via the indirect inclusion of hMSCs in this study can act as a starting point for future direct coculture and in vivo investigations.

A population-based propensity-matched study of regional dissections in patients with metastatic osteosarcoma

Background

The survival rates of patients with metastatic osteosarcoma are poor, and the prognosis is closely related to the choice of treatment, especially surgery. This study aimed to evaluate the survival outcomes of patients with metastatic osteosarcoma undergoing regional dissections.

Methods

We collected data on patients with metastatic osteosarcoma between 2004 and 2014 from the Surveillance, Epidemiology, and End Results (SEER) database. Kaplan–Meier curves were used to compare overall survival (OS) and cancer-specific survival (CSS), while univariate and multivariate Cox regression analyses were used to evaluate outcomes. Propensity score matching (PSM) was used to minimize the effects of confounding factors.

Results

The SEER database had records of 2768 patients diagnosed with osteosarcoma, of whom 398 were included in our study. Of the included patients, 116 (29.15%) underwent regional dissections, while 282 (70.85%) underwent non-regional dissections. The univariate and multivariate Cox regression analyses, prior to PSM, showed that OS (hazard ratio (HR): 0.34, 95% confidence interval (CI): 0.26–0.44, P<0.001 and HR: 0.47, 95% CI: 0.35–0.64, P<0.001, respectively) and CSS (HR: 0.33, 95% CI: 0.25–0.43, P<0.001 and HR: 0.46, 95% CI: 0.34–0.63, P<0.001, respectively) were better in patients who underwent regional dissections than those who underwent non-regional dissections. Compared with non-regional dissections, regional dissections, which included both primary tumour resection (PTR) and primary tumour and metastatic site resection (PTMR), were associated with better OS (P<0.001) and CSS (P<0.001) . However, the survival outcomes following PTR and PTMR showed no significant difference. After PSM, patients in the regional dissection group still had a higher OS (P<0.001) and CSS (P<0.001) than those in the non-regional dissection group.

Conclusions

Compared with non-regional dissection, regional dissection resulted in better survival in patients with metastatic osteosarcoma.

MicroRNA‑145‑5p inhibits osteosarcoma cell proliferation by targeting E2F transcription factor 3

Osteosarcoma is a common type of bone tumor that primarily occurs in children and young adults. MicroRNA (miRNA/miR) dysregulation is associated with the progression of osteosarcoma; therefore, the aim of the present study was to investigate the biological functions and molecular mechanisms of miR-145-5p in osteosarcoma. The expression of miR-145-5p in osteosarcoma tissues and cell lines was quantified using reverse transcription-quantitative PCR (RT-qPCR). The effect of miR-145-5p on the proliferation of osteosarcoma cells was detected using Cell Counting Kit-8 and colony formation assays, as well as cell cycle distribution analysis. The effect of miR-145-5p on tumor growth was further investigated in vivo using a subcutaneous tumor model in nude mice. The interaction between miR-145-5p and E2F transcription factor 3 (E2F3) was determined using bioinformatics analysis, a luciferase assay, RT-qPCR and western blotting. The results revealed that miR-145-5p expression was decreased in osteosarcoma cell lines and tissues compared with the corresponding normal controls. Increased miR-145-5p expression inhibited the proliferation and colony formation ability of osteosarcoma cells, and induced G₁ phase arrest. Furthermore, mice injected with tumor cells overexpressing miR-145-5p exhibited smaller tumors than those in the control group. Further investigation revealed that miR-145-5p binds to and decreases the expression of E2F3. In addition, the mRNA levels of E2F3 were negatively associated with miR-145-5p in osteosarcoma tissues, and increasing E2F3 expression abrogated the inhibitory effects of miR-145-5p on osteosarcoma cells. Collectively, the results obtained in the present study suggest that miR-145-5p may suppress the progression of osteosarcoma, and may serve as a useful biomarker for the diagnosis of osteosarcoma, as well as a therapeutic target.

Common genetic variation and risk of osteosarcoma in a multi-ethnic pediatric and adolescent population

Osteosarcoma, a malignant primary bone tumor most commonly diagnosed in children and adolescents, has a poorly understood genetic etiology. Genome-wide association studies (GWAS) and candidate-gene analyses have identified putative risk variants in subjects of European ancestry. However, despite higher incidence among African-American and Hispanic children, little is known regarding common heritable variation that contributes to osteosarcoma incidence and clinical presentation across racial/ethnic groups. In a multi-ethnic sample of non-Hispanic white, Hispanic, African-American and Asian/Pacific Islander children (537 cases, 2165 controls), we performed association analyses assessing previously-reported loci for osteosarcoma risk and metastasis, including meta-analysis across racial/ethnic groups. We also assessed a previously described association between genetic predisposition to longer leukocyte telomere length (LTL) and osteosarcoma risk in this independent multi-ethnic dataset. In our sample, we were unable to replicate previously-reported loci for osteosarcoma risk or metastasis detected in GWAS of European-ancestry individuals in either ethnicity-stratified analyses or meta-analysis across ethnic groups. Our analyses did confirm that genetic predisposition to longer LTL is a risk factor for osteosarcoma (ORmeta: 1.22; 95% CI: 1.09-1.36; P = 3.8 × 10-4), and the strongest effect was seen in Hispanic subjects (OR: 1.32; 95% CI: 1.12-1.54, P = 6.2 × 10-4). Our findings shed light on the replicability of osteosarcoma risk loci across ethnicities and motivate further characterization of these genetic factors in diverse clinical cohorts.

Radiomics signature extracted from diffusion-weighted magnetic resonance imaging predicts outcomes in osteosarcoma

OBJECTIVE

Osteosarcoma often requires multidisciplinary treatment including surgery, chemotherapy and radiotherapy. However, tumor behavior can vary widely among patients and selection of appropriate therapies in any individual patient remains a critical challenge. Radiomics seeks to quantify complex aspects of tumor images under the assumption that this information is related to tumor biology. This study tested the hypothesis that a radiomic signature extracted from Diffusion-weighted magnetic resonance images (DWI-MRI) can improve prediction of overall survival (OS) compared with clinical factors alone in localised osteosarcoma.

MATERIALS/METHODS

Pre-treatment DWI-MRI were collected from 112 patients (9-67 years of age) with histological-proven osteosarcoma that were treated with curative intent. The entire dataset was divided in two subsets: the training and validation cohorts containing 76 and 24% of the data respectively. Clinical data were extracted from our medical record. Two experienced radiotherapists evaluated DWI-MRIs for quality and segmented the tumor. A total of 103 radiomic features were calculated for each image. Least absolute shrinkage and selection operator (LASSO) regression was applied to select features. Association between the radiomics signature and OS was explored. Further validation of the radiomics signature as an independent biomarker was performed by using multivariate Cox regression. The Cox proportional-hazard regression model was also used to analyze the correlation between the prognostic factor and the survival for the clinical (C) model after the univariate analysis. Radiomics (R) model identified radiomics signature, which is the best predictor from the radiomic variable classes based on LASSO regression. Harrell's C-index was used to demonstrate the incremental value of the radiomics signature to the traditional clinical risk factors for the individualized prediction performance.

RESULTS

Cox proportional-hazard regression model shows that: Tumor size, alkaline phosphatase (ALP) status before treatment and number of courses of chemotherapy were proven as the dependent clinical prognostic factors of osteosarcoma's overall survival time. The radiomics signature was significantly associated with OS, independent of clinical risk factors (radiomics signature: HR: 5.11, 95% CI: 2.85, 9.18, P < 0.001). Incorporating the radiomics signature into the coalition (C+R) model resulted in better performance (P < .001) for the estimation of OS (C-index: 0.813; 95% CI: 0.75, 0.89) than with the clinical (C) model (C-index: 0.764; 95% CI: 0.69, 0.85), or the single radiomics (R) model (C-index: 0.712; 95% CI: 0.65, 0.78).

CONCLUSION

This study shows that the radiomics signature extracted from pre-treatment DWI-MRI improve prediction of OS over clinical features alone. Combination of the radiomics signature and the traditional clinical risk factors performed better for individualized OS estimation in patients with osteosarcoma, which might enable a step forward precise medicine. This method may help better select patients most likely to benefit from intensified multimodality diagnosis and therapies. Future studies will focus on multi-center validation of an optimized model.

Risk Factors for Development of Canine and Human Osteosarcoma: A Comparative Review

Osteosarcoma is the most common primary tumor of bone. Osteosarcomas are rare in humans, but occur more commonly in dogs. A comparative approach to studying osteosarcoma has highlighted many clinical and biologic aspects of the disease that are similar between dogs and humans; however, important species-specific differences are becoming increasingly recognized. In this review, we describe risk factors for the development of osteosarcoma in dogs and humans, including height and body size, genetics, and conditions that increase turnover of bone-forming cells, underscoring the concept that stochastic mutational events associated with cellular replication are likely to be the major molecular drivers of this disease. We also discuss adaptive, cancer-protective traits that have evolved in large, long-lived mammals, and how increasing size and longevity in the absence of natural selection can account for the elevated bone cancer risk in modern domestic dogs.

GAPLINC is a predictor of poor prognosis and regulates cell migration and invasion in osteosarcoma

Gastric adenocarcinoma predictive long intergenic non-coding (GAPLINC) is a novel long non-coding RNA (lncRNA) and has been found to function as an oncogenic lncRNA in gastric cancer, colorectal cancer, and bladder cancer. The expression status and biological function of GAPLINC in osteosarcoma are still unknown. Thus, we analyzed the association between GAPLINC expression and clinicopathological characteristics in osteosarcoma clinical samples, and conducted loss-of-function study in osteosarcoma cell lines. In our results, GAPLINC expression is elevated in osteosarcoma tissues and cell lines, and correlated with advanced Enneking stage, present distant metastasis, and poor histological grade. Survival analyses indicated that GAPLINC expression was negatively associated with overall survival, and GAPLINC high-expression was an independent risk factor in osteosarcoma patients. The in vitro studies showed knockdown of GAPLINC depressed osteosarcoma cell migration and invasion via inhibiting CD44 expression, but no effect on cell proliferation. In conclusion, GAPLINC may serve as a potential biomarker for predicting prognosis and developing therapy for osteosarcoma.

Osteosarcoma in patients below 25 years of age: An observational study of incidence, metastasis, treatment and outcomes

Only few systematic and comprehensive studies have focused on osteosarcoma in children and adolescents. In the present study, 3,085 patients with osteosarcoma were identified in the Surveillance, Epidemiology and End Results Program database. The patients were <25 years of age and diagnosed between 1973 to 2012. A retrospective study was performed to investigate the factors associated with tumor incidence, metastasis, treatment and survival. The results indicated that the incidence of osteosarcoma was higher in male patients compared with female patients. In addition, the incidence rate of osteosarcoma was higher among male and female patients between the ages of 10 and 19. Osteosarcoma located in the chest and pelvic bones was associated with metastatic disease; however, metastasis in two histological types, parosteal and periosteal, was infrequent. Survival analysis revealed the following were associated with poor outcomes: Sex, patients diagnosed between 1973 and 1982, distant metastasis, treatment without surgery or with radiation, a tumor with a poorly differentiated or undifferentiated grade, tumor size ≥100 mm, and a tumor in the pelvic bones. Patient's whose histologic type was parosteal osteosarcoma and whose tumor was located in one of the limbs, or who underwent local or radical excision, exhibited a good survival outcome. Survival outcomes were ranked according to the type of surgery, from best to worst, as follows: Local excision, radical excision, amputation and no surgery. In summary, the incidence of osteosarcoma is higher in male patients compared with female patients. Furthermore, individuals between the ages of 10 and 19 have a higher risk of osteosarcoma. Osteosarcoma located in the chest and pelvic bones has a high risk of metastasis. Limb-salvage surgery may be the optimal treatment approach for non-metastatic osteosarcoma.

Genetic determinants of childhood and adult height associated with osteosarcoma risk

BACKGROUND

Although increased height has been associated with osteosarcoma risk in previous epidemiologic studies, to the authors' knowledge the relative contribution of stature during different developmental timepoints remains unclear. Furthermore, the question of how genetic determinants of height impact osteosarcoma etiology remains unexplored. Genetic variants associated with stature in previous genome-wide association studies may be biomarkers of osteosarcoma risk.

METHODS

The authors tested the associations between osteosarcoma risk and polygenic scores for adult height (416 variants), childhood height (6 variants), and birth length (5 variants) in 864 osteosarcoma cases and 1879 controls of European ancestry.

RESULTS

Each standard deviation increase in the polygenic score for adult height, corresponding to a 1.7-cm increase in stature, was found to be associated with a 1.10-fold increase in the risk of osteosarcoma (95% confidence interval [95% CI], 1.01-1.19; P =.027). Each standard deviation increase in the polygenic score for childhood height, corresponding to a 0.5-cm increase in stature, was associated with a 1.10-fold increase in the risk of osteosarcoma (95% CI, 1.01-1.20; P =.023). The polygenic score for birth length was not found to be associated with osteosarcoma risk (P =.11). When adult and childhood height scores were modeled together, they were found to be independently associated with osteosarcoma risk (P =.037 and P = .043, respectively). An expression quantitative trait locus for cartilage intermediate layer protein 2 (CILP2), rs8103992, was significantly associated with osteosarcoma risk after adjustment for multiple comparisons (odds ratio, 1.35; 95% CI, 1.16-1.56 [P = 7.93×10-5 and Padjusted =.034]).

CONCLUSIONS

A genetic propensity for taller adult and childhood height attainments contributed independently to osteosarcoma risk in the current study data. These results suggest that the biological pathways affecting normal bone growth may be involved in osteosarcoma etiology.

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.

miR-34 inhibits growth and promotes apoptosis of osteosarcoma in nude mice through targetly regulating TGIF2 expression

miR-34 was reported to be involved in multiple tumors occurrence and development. The aim of the present study was to explore the impact of miR-34 on osteosarcoma and related mechanisms. Tumor tissues and non-tumor tissues of 34 patients with osteosarcoma were collected. qRT-PCR detection revealed that miR-34 was significantly down-regulated in tumor tissues (P<0.05). hFOB 1.19 and MG-63 cells were cultured. qRT-PCR detection showed that miR-34 was also significantly down-regulated in MG-63 cells (P<0.05). After transfection by miR-34 mimics, MG-63 cells proliferation in nude mice was significantly impaired (P<0.05), and percentage of apoptosis as well as caspase-3 positive cells proportion of osteosarcoma tissue in nude mice was markly increased (P<0.05). Western blot and immunofluorescence results also demonstrated that TGIF2 relative expression and TGIF2 positive cells proportion were both dramatically decreased (P<0.05). By luciferase reporter assay, we found that TGIF2 was the target gene of miR-34. After transfected by TGIF2 overexpression vector or co-transfected by miR-34 mimics and TGIF2 overexpression vector, we observed that, compared with blank group, tumor volume was significantly increased and apoptotic cells as well as caspase-3 positive cells proportion was obviously decreased in TGIF2 group (P<0.05), while no significant difference was found in these indicators between blank group and TGIF2 + mimics group. We concluded that miR-34 inhibited growth and promoted apoptosis of osteosarcoma in nude mice through targetting regulated TGIF2 expression.

Knockdown of Sox2 Inhibits OS Cells Invasion and Migration via Modulating Wnt/β-Catenin Signaling Pathway

Osteosarcoma (OS) was a prevalent malignant bone tumor which threatens people's health worldwide. Wnt/β catenin signaling pathway had been proved significant in various cancers, indicating its possible function in OS as well. Sox2, a crucial member among SOX family could regulate cells biologically. How Sox2 modulated Wnt/β catenin signaling pathway in OS remained to be discussed. The study aimed to investigate the effects of Sox2 on the invasion and migration of OS cells and the related molecular mechanisms. Twenty-four human OS and adjacent tissue samples were involved in this study. Human OS cell lines MG63 and HOS were selected for further investigation. The liposome carrier si-Sox2 which could interfere with the expression of Sox2 gene was built to transfect MG63 and HOS cells). QRT-PCR assay and western blot were utilized to analyze the expression of mRNA and proteins of Sox2. Transwell assay and wound healing assay were conducted to test the invasion and migration level of cells. The expression of GSK3, β-catenin, cyclin D1 and c-myc proteins were detected by western blot assay after transfection with si-Sox2. Compared with normal tissues and cells, the expression of Sox2 in OS tissues and cells was significantly higher. The mRNA and protein levels of Sox2 significantly decreased after transfection with si-Sox2. The invasion and migration of OS cells were down-regulated significantly through the inhibition of Sox2 by inactivating Wnt/β-catenin signaling pathway related proteins. Knockdown of Sox2 could inhibit invasion and migration of OS cells via modulating Wnt/β-catenin signaling pathway.