VEGF expression as a prognostic marker in osteosarcoma

From biology to personalized medicine: Recent knowledge in osteosarcoma

High-grade osteosarcoma is the most common paediatric bone cancer. More than one third of patients relapse and die of osteosarcoma using current chemotherapeutic and surgical strategies. To improve outcomes in osteosarcoma, two crucial challenges need to be tackled: 1-the identification of hard-to-treat disease, ideally from diagnosis; 2- choosing the best combined or novel therapies to eradicate tumor cells which are resistant to current therapies leading to disease dissemination and metastasize as well as their favorable microenvironment. Genetic chaos, tumor complexity and heterogeneity render this task difficult. The development of new technologies like next generation sequencing has led to an improvement in osteosarcoma oncogenesis knownledge. This review summarizes recent biological and therapeutical advances in osteosarcoma, as well as the challenges that must be overcome in order to develop personalized medicine and new therapeutic strategies and ultimately improve patient survival.

Correlation of High-Grade Osteosarcoma Response to Chemotherapy with Enhanced Tissue Immunological Response: Analysis of CD95R, IFN-γ, Catalase, Hsp70, and VEGF

High-grade osteosarcoma, a primary malignant bone tumour, is experiencing a global increase in reported incidence with varied prevalence. Despite advances in management, which include surgery and neoadjuvant chemotherapy often an unsatisfactory outcome is found due to poor or heterogeneous response to chemotherapy. Our study delved into chemotherapy responses in osteosarcoma patients and associated molecular expressions, focusing on CD95 receptor (CD95R), interferon (IFN)-γ, catalase, heat-shock protein (Hsp)70, and vascular endothelial growth factor (VEGF). Employing immunohistochemistry and Huvos grading of post-chemo specimens, we analysed formalin-fixed paraffin-embedded (FFPE) osteosarcoma tissue of resected post-chemotherapy specimens from Dr. Soetomo General Academic Hospital in Surabaya, Indonesia (DSGAH), spanning from 2016 to 2020. Results revealed varied responses (poor 40.38%, moderate 48.08%, good 11.54%) and distinct patterns in CD95R, IFN-γ, catalase, Hsp70, and VEGF expression. Significant differences among response groups were observed in CD95R and IFN-γ expression in tumour-infiltrating lymphocytes. The trend of diminishing CD95R expression from poor to good responses, accompanied by an increase in IFN-γ, implied a reduction in the count of viable osteosarcoma cells with the progression of Huvos grading. Catalase expression in osteosarcoma cells was consistently elevated in the poor response group, while Hsp70 expression was highest. VEGF expression in macrophages was significantly higher in the good response group. In conclusion, this study enhances our understanding of immune-chemotherapy interactions in osteosarcoma and identifies potential biomarkers for targeted interventions.

Active targeting schemes for nano-drug delivery systems in osteosarcoma therapeutics

Osteosarcoma, the most common malignant tumor of the bone, seriously influences people's lives and increases their economic burden. Conventional chemotherapy drugs achieve limited therapeutic effects owing to poor targeting and severe systemic toxicity. Nanocarrier-based drug delivery systems can significantly enhance the utilization efficiency of chemotherapeutic drugs through targeting ligand modifications and reduce the occurrence of systemic adverse effects. A variety of ligand-modified nano-drug delivery systems have been developed for different targeting schemes. Here we review the biological characteristics and the main challenges of current drug therapy of OS, and further elaborate on different targeting schemes and ligand selection for nano-drug delivery systems of osteosarcoma, which may provide new horizons for the development of advanced targeted drug delivery systems in the future.

Formulation and validation of a baseline prognostic score for osteosarcoma treated uniformly with a non-high dose methotrexate-based protocol from a low middle income healthcare setting: a single centre analysis of 594 patients

Introduction

The outcomes of osteosarcoma in low middle income countries (LMICs) are different due to patients presenting in advanced stages, resource constraints and the use of non-high-dose-methotrexate (HDMTX)-based regimens. This study derived and validated a prognostic score for osteosarcoma that integrates biologic and social factors and is tailored for patients from an LMIC setting using a non-HDMTX-based protocol.

Materials and methods

A retrospective study including osteosarcoma patients enrolled for treatment at a single tertiary care centre in India between 2003-19 was conducted. Baseline biologic and social characteristics were extracted from medical records and survival outcomes were noted. The cohort was randomised into a derivation and validation cohort. Multivariable Cox regression was used to identify baseline characteristics that were independently prognostic for survival outcomes in the derivation cohort. A score was derived from the prognostic factors identified in the derivation cohort and further validated in the validation cohort with estimation of its predictive ability.

Results

594 patients with osteosarcoma were eligible for inclusion in the study. Around one-third of the cohort had metastatic disease with 59% of the patients residing in rural areas. The presence of metastases at baseline (HR 3.39; p<0.001; score=3), elevated serum alkaline phosphatase (SAP) >450 IU/L (HR 1.57; p=0.001; score=1) and baseline tumour size > 10 cm (HR 1.68; p<0.001; score=1) were identified to be independent factors predicting inferior event free survival (EFS) and were included in development of the prognostic score. Patients were categorized as low risk (score 0), intermediate risk (score 1-3) and high risk (4-5). Harrell's c-indices for the score were 0.682, 0.608 and 0.657 respectively for EFS in the derivation, validation and whole cohort respectively. The timed AUC of ROC was 0.67 for predicting 18-month EFS in the derivation, validation and whole cohorts while that for 36-month EFS were 0.68, 0.66 and 0.68 respectively.

Conclusions

The study describes the outcomes among osteosarcoma patients from an LMIC treated uniformly with a non-HDMTX-based protocol. Tumor size, baseline metastases and SAP were prognostic factors used to derive a score with good predictive value for survival outcomes. Social factors did not emerge as determinants of survival.

Non-invasive intravoxel incoherent motion MRI in prediction of histopathological response to neoadjuvant chemotherapy and survival outcome in osteosarcoma at the time of diagnosis

BACKGROUND

Early prediction of response to neoadjuvant chemotherapy (NACT) is important to aid personalized treatment in osteosarcoma. Diffusion-weighted Intravoxel Incoherent Motion (IVIM) MRI was used to evaluate the predictive value for response to NACT and survival outcome in osteosarcoma.

METHODS

Total fifty-five patients with biopsy-proven osteosarcoma were recruited prospectively, among them 35 patients were further analysed. Patients underwent 3 cycles of NACT (Cisplatin + Doxorubicin) followed by surgery and response adapted adjuvant chemotherapy. Treatment outcomes were histopathological response to NACT (good-response ≥ 50% necrosis and poor-response < 50% necrosis) and survival outcome (event-free survival (EFS) and overall survival (OS)). IVIM MRI was acquired at 1.5T at baseline (t0), after 1-cycle (t1) and after 3-cycles (t2) of NACT. Quantitative IVIM parameters (D, D*, f & D*.f) were estimated using advanced state-of-the-art spatial penalty based IVIM analysis method bi-exponential model with total-variation penalty function (BETV) at 3 time-points and histogram analysis was performed.

RESULTS

Good-responders: Poor-responders ratio was 13 (37%):22 (63%). EFS and OS were 31% and 69% with 16.27 and 25.9 months of median duration respectively. For predicting poor-response to NACT, IVIM parameters showed AUC = 0.87, Sensitivity = 86%, Specificity = 77% at t0, and AUC = 0.96, Sensitivity = 86%, Specificity = 100% at t1. Multivariate Cox regression analysis showed smaller tumour volume (HR = 1.002, p = 0.001) higher ADC-25th-percentile (HR = 0.047, p = 0.005) & D-Mean (HR = 0.1, p = 0.023) and lower D*-Mean (HR = 1.052, p = 0.039) were independent predictors of longer EFS (log-rank p-values: 0.054, 0.0034, 0.0017, 0.0019 respectively) and non-metastatic disease (HR = 4.33, p < 10-3), smaller tumour-volume (HR = 1.001, p = 0.042), lower D*-Mean (HR = 1.045, p = 0.056) and higher D*.f-skewness (HR = 0.544, p = 0.048) were independent predictors of longer OS (log-rank p-values: < 10-3, 0.07, < 10-3, 0.019 respectively).

CONCLUSION

IVIM parameters obtained with a 1.5T scanner along with novel BETV method and their histogram analysis indicating tumour heterogeneity were informative in characterizing NACT response and survival outcome in osteosarcoma.

Controversies and Challenges in the Management of Osteosarcoma-an Indian Perspective

Osteosarcoma (OGS) is the most common primary bone tumor in children and adolescents which requires a multidisciplinary approach to management. Although chemotherapy and surgery can cure more than half of localized OGS cases, the unique challenges faced by resource-limited countries like India make this outcome difficult to achieve. Various questions in the management of OGS including role of high-dose methotrexate (HDMTX) in neoadjuvant setting, triplet vs doublet chemotherapy, intensification of chemotherapy based on response in setting of doublet, and indigenous prosthesis in setting of limb salvage need to be defined. Similarly, in the metastatic and recurrent setting, questions regarding intent of treatment, indications of chemotherapy, timing of surgery, and role of targeted therapies need clarification. Lack of randomized trials from India makes definite conclusions difficult, but an attempt can be made to define the best approach in the Indian scenario from available evidence. Hence, a critical review of literature from India and the West was done to define possible management approaches and highlight the lacuna for future research.

Regorafenib for the Treatment of Sarcoma

OPINION STATEMENT

Sarcomas are a rare group of tumors with many subtypes, conventionally classified into soft-tissue sarcomas and bone sarcomas. Chemotherapeutic regimens form the mainstay of systemic therapy but are not well defined beyond the first-line setting and clinical outcomes are variable. Tyrosine kinase inhibitors (TKIs), with a broad inhibition profile which have been shown to target tumor angiogenesis, have an established role in the treatment of sarcomas without characteristic driver alterations. One such TKI, regorafenib, has been evaluated in sarcomas and clinical data are discussed in this review. An overview of regorafenib data from five phase 2 and one phase 1b clinical trials in over 10 sarcoma subtypes (both soft-tissue and bone) in adult and pediatric patients is reviewed. Regorafenib demonstrated clinical benefit in patients with non-adipocytic soft-tissue sarcomas, osteosarcoma and Ewing sarcoma who had progressed on prior therapy. Patients with otherwise limited treatment options may therefore benefit from regorafenib therapy.

Interleukin 17 and Its Involvement in Renal Cell Carcinoma

Nowadays, molecular and immunological research is essential for the better understanding of tumor cells pathophysiology. The increasing number of neoplasms has been taken under ‘the molecular magnifying glass’ and, therefore, it is possible to discover complex relationships between the cytophysiology and immune system action. An example could be renal cell carcinoma (RCC) which has deep interactions with immune mediators such as Interleukin 17 (IL-17)—an inflammatory cytokine reacting to tissue damage and external pathogens. RCC is one of the most fatal urological cancers because of its often late diagnosis and poor susceptibility to therapies. IL-17 and its relationship with tumors is extremely complex and constitutes a recent topic for numerous studies. What is worth highlighting is IL-17’s dual character in cancer development—it could be pro- as well as anti-tumorigenic. The aim of this review is to summarize the newest data considering multiple connections between IL-17 and RCC.

Single-cell RNA sequencing reveals differential expression of EGFL7 and VEGF in giant-cell tumor of bone and osteosarcoma

Dysregulation of angiogenesis is associated with tumor development and is accompanied by altered expression of pro-angiogenic factors. EGFL7 is a newly identified antigenic factor that plays a role in various cancers such as breast cancer, lung cancer, and acute myeloid leukemia. We have recently found that EGFL7 is expressed in the bone microenvironment, but its role in giant-cell tumor of bone (GCTB) and osteosarcoma (OS) is unknown. The aims of this study are to examine the gene expression profile of EGFL7 in GCTB and OS and compare with that of VEGF-A-D and TNFSF11 using single-cell RNA sequencing data. In-depth differential expression analyses were employed to characterize their expression in the constituent cell types of GCTB and OS. Notably, EGFL7 in GCTB was expressed at highest levels in the endothelial cell (EC) cluster followed by osteoblasts, myeloid cells, and chondrocytes, respectively. In OS, EGFL7 exhibited highest expression in EC cell cluster followed by osteoblastic OS cells, myeloid cells 1, and carcinoma associated fibroblasts (CAFs), respectively. In comparison, VEGF-A is expressed at highest levels in myeloid cells followed by OCs in GCTB, and in myeloid cells, and OCs in OS. VEGF-B is expressed at highest levels in chondrocytes in GCTB and in OCs in OS. VEGF-C is strongly enriched in ECs and VEGF-D is expressed at weak levels in all cell types in both GCTB and OS. TNFSF11 (or RANKL) shows high expression in CAFs and osteoblastic OS cells in OS, and osteoblasts in GCTB. This study investigates pro-angiogenic genes in GCTB and OS and suggests that these genes and their expression patterns are cell-type specific and could provide potential prognostic biomarkers and cell type target treatment for GCTB and OS.

Correlation of vascular endothelial growth factor with survival and pathological characteristics of patients with osteosarcoma: A systematic review and meta-analysis

OBJECTIVE

This study aimed to assess the prognostic role of vascular endothelial growth factor (VEGF) expression in osteosarcoma.

METHODS

Systematic searches of PubMed, Embase, CINAHL, Cochrane Library, ScienceDirect, and Web of Science were conducted. The correlation between VEGF expression and patients' survival was our primary endpoint. The secondary endpoints were the associations between VEGF level and patients' sociodemographic and pathological characteristics. The pooled hazard ratio (HR) or odd ratio (OR) and corresponding 95% confidence intervals (CIs) were obtained to assess the associations between VEGF expression and the target factors. Subgroup and meta-regression analyses were conducted to explore potential factors that associated with VEGF efficacy.

RESULTS

The combined HR suggested that a positive VEGF status has a negative impact on overall survival (OS) (HR = 2.58; 95% CI, 2.09-3.19; P < 0.0001) and disease-free survival (DFS) (HR = 2.54; 95% CI, 1.84-3.50; P < 0.0001) in patients with osteosarcoma. Meta-regression analysis ruled out the influence of cut-off value, disease stage, histological subtype, disease grade, tumour location, geographic area, publication year, and method of HR acquisition on heterogeneity. Results showed that VEGF expression was closely correlated with tumour staging, chemotherapy response, and metastasis.

CONCLUSION

Based on the study results, VEGF could serve as an effective biomarker of prognosis in patients with osteosarcoma. Besides, VEGF was related to increased tumour malignancy, which might help guide clinical decision-making regarding therapy and outcomes.

Introducing Fluorescence-Guided Surgery for Pediatric Ewing, Osteo-, and Rhabdomyosarcomas: A Literature Review

Sarcomas are a rare heterogeneous group of malignant neoplasms of mesenchymal origin which represent approximately 13% of all cancers in pediatric patients. The most prevalent pediatric bone sarcomas are osteosarcoma (OS) and Ewing sarcoma (ES). Rhabdomyosarcoma (RMS) is the most frequently occurring pediatric soft tissue sarcoma. The median age of OS and ES is approximately 17 years, so this disease is also commonly seen in adults while non-pleiomorphic RMS is rare in the adult population. The mainstay of all treatment regimens is multimodal treatment containing chemotherapy, surgical resection, and sometimes (neo)adjuvant radiotherapy. A clear resection margin improves both local control and overall survival and should be the goal during surgery with a curative intent. Real-time intraoperative fluorescence-guided imaging could facilitate complete resections by visualizing tumor tissue during surgery. This review evaluates whether non-targeted and targeted fluorescence-guided surgery (FGS) could be beneficial for pediatric OS, ES, and RMS patients. Necessities for clinical implementation, current literature, and the positive as well as negative aspects of non-targeted FGS using the NIR dye Indocyanine Green (ICG) were evaluated. In addition, we provide an overview of targets that could potentially be used for FGS in OS, ES, and RMS. Then, due to the time- and cost-efficient translational perspective, we elaborate on the use of antibody-based tracers as well as their disadvantages and alternatives. Finally, we conclude with recommendations for the experiments needed before FGS can be implemented for pediatric OS, ES, and RMS patients.

Alpha Ketoglutarate Exerts In Vitro Anti-Osteosarcoma Effects through Inhibition of Cell Proliferation, Induction of Apoptosis via the JNK and Caspase 9-Dependent Mechanism, and Suppression of TGF-β and VEGF Production and Metastatic Potential of Cells

Osteosarcoma (OS) is the most common type of primary bone tumor. Currently, there are limited treatment options for metastatic OS. Alpha-ketoglutarate (AKG), i.e., a multifunctional intermediate of the Krebs cycle, is one of the central metabolic regulators of tumor fate and plays an important role in cancerogenesis and tumor progression. There is growing evidence suggesting that AKG may represent a novel adjuvant therapeutic opportunity in anti-cancer therapy. The present study was intended to check whether supplementation of Saos-2 and HOS osteosarcoma cell lines (harboring a TP53 mutation) with exogenous AKG exerted an anti-cancer effect. The results revealed that AKG inhibited the proliferation of both OS cell lines in a concentration-dependent manner. As evidenced by flow cytometry, AKG blocked cell cycle progression at the G₁ stage in both cell lines, which was accompanied by a decreased level of cyclin D1 in HOS and increased expression of p21^Waf1/Cip1 protein in Saos-2 cells (evaluated with the ELISA method). Moreover, AKG induced apoptotic cell death and caspase-3 activation in both OS cell lines (determined by cytometric analysis). Both the immunoblotting and cytometric analysis revealed that the AKG-induced apoptosis proceeded predominantly through activation of an intrinsic caspase 9-dependent apoptotic pathway and an increased Bax/Bcl-2 ratio. The apoptotic process in the AKG-treated cells was mediated via c-Jun N-terminal protein kinase (JNK) activation, as the specific inhibitor of this kinase partially rescued the cells from apoptotic death. In addition, the AKG treatment led to reduced activation of extracellular signal-regulated kinase (ERK1/2) and significant inhibition of cell migration and invasion in vitro concomitantly with decreased production of pro-metastatic transforming growth factor β (TGF-β) and pro-angiogenic vascular endothelial growth factor (VEGF) in both OS cell lines suggesting the anti-metastatic potential of this compound. In conclusion, we showed the anti-osteosarcoma potential of AKG and provided a rationale for a further study of the possible application of AKG in OS therapy.

Exploring the Role of Osteosarcoma-Derived Extracellular Vesicles in Pre-Metastatic Niche Formation and Metastasis in the 143-B Xenograft Mouse Osteosarcoma Model

Simple Summary

Osteosarcoma is an aggressive bone cancer that frequently metastasizes to the lungs and is the second leading cause of cancer-associated death in children and adolescents. Therefore, deciphering the biological mechanisms that mediate osteosarcoma metastasis is urgently needed in order to develop effective treatment. The aim of our study was to shed light on the primary tumor-induced changes in the lungs prior to osteosarcoma cell arrival using a xenograft osteosarcoma mouse model. Furthermore, we investigated the functional role of osteosarcoma-derived extracellular vesicles in pre-metastatic niche formation and metastasis. We showed that the primary tumor initiates an influx of CD11b⁺ myeloid cells in the pre-metastatic lungs. Furthermore, we demonstrated that osteosarcoma-derived extracellular vesicles alone can recapitulate myeloid cell infiltration in the lungs of naïve mice, but are insufficient to promote osteosarcoma metastasis. Our findings provide valuable insight into the field of osteosarcoma-derived extracellular vesicles and their role in pre-metastatic niche formation in the 143-B osteosarcoma model.

Abstract

The pre-metastatic niche (PMN) is a tumor-driven microenvironment in distant organs that can foster and support the survival and growth of disseminated tumor cells. This facilitates the establishment of secondary lesions that eventually form overt metastasis, the main cause of cancer-related death. In recent years, tumor-derived extracellular-vesicles (EVs) have emerged as potentially key drivers of the PMN. The role of the PMN in osteosarcoma metastasis is poorly understood and the potential contribution of osteosarcoma cell-derived EVs to PMN formation has not been investigated so far. Here, we characterize pulmonary PMN development using the spontaneously metastasizing 143-B xenograft osteosarcoma mouse model. We demonstrate the accumulation of CD11b⁺ myeloid cells in the pre-metastatic lungs of tumor-bearing mice. We also establish that highly metastatic 143-B and poorly metastatic SAOS-2 osteosarcoma cell-derived EV education in naïve mice can recapitulate the recruitment of myeloid cells to the lungs. Surprisingly, despite EV-induced myeloid cell infiltration in the pre-metastatic lungs, 143-B and SAOS-2 EVs do not contribute towards the 143-B metastatic burden in the context of both spontaneous as well as experimental metastasis in severe-combined immunodeficient (SCID) mice. Taken together, OS-derived EVs alone may not be able to form a functional PMN, and may perhaps require a combination of tumor-secreted factors along with EVs to do so. Additionally, our study gives a valuable insight into the PMN complexity by providing the transcriptomic signature of the premetastatic lungs in an osteosarcoma xenograft model for the first time. In conclusion, identification of regulators of cellular and molecular changes in the pre-metastatic lungs might lead to the development of a combination therapies in the future that interrupt PMN formation and combat osteosarcoma metastasis.

Surface engineering of nanoparticles with ligands for targeted delivery to osteosarcoma

Osteosarcoma is one of the most common malignant bone tumors which affect adolescents. Neoadjuvant chemotherapy followed by operation has become recommended for osteosarcoma treatment. Whereas, the effects of conventional chemotherapy are unsatisfactory because of multidrug resistance, fast clearance rate, nontargeted delivery, side effects and so on. Accordingly, Nanoparticle-mediated targeted drug delivery system (NTDDS) is recommended to be a novel treatment strategy for osteosarcoma. NTDDS can overcome the above obstacles by enhanced permeability and retention effect and active targeting. The active targeting of the delivery system is mainly based on ligands. In this study, we investigate and summarize the most common ligands used in the latest NTDDS for osteosarcoma. It might provide new insights into nanomedicine for osteosarcoma treatment.

Nanomedicine in osteosarcoma therapy: Micelleplexes for delivery of nucleic acids and drugs toward osteosarcoma-targeted therapies

Osteosarcoma(OS) represents the main cancer affecting bone tissue, and one of the most frequent in children. In this review we discuss the major pathological hallmarks of this pathology, its current therapeutics, new active biomolecules, as well as the nanotechnology outbreak applied to the development of innovative strategies for selective OS targeting. Small RNA molecules play a role as key-regulator molecules capable of orchestrate different responses in what concerns cancer initiation, proliferation, migration and invasiveness. Frequently associated with lung metastasis, new strategies are urgent to upgrade the therapeutic outcomes and the life-expectancy prospects. Hence, the prominent rise of micelleplexes as multifaceted and efficient structures for nucleic acid delivery and selective drug targeting is revisited here with special emphasis on ligand-mediated active targeting. Future landmarks toward the development of novel nanostrategies for both OS diagnosis and OS therapy improvements are also discussed.

Caveolin-1 Expression Together with VEGF can be a Predictor for Lung Metastasis and Poor Prognosis in Osteosarcoma

Caveolin-1, the major protein component of caveolae, plays vital functions in tumorigenesis and metastasis. Previous evidence demonstrated the positive role of Caveolin-1 in the regulation of endothelial cell differentiation and the involvement of Caveolin-1 in vascular endothelial growth factor (VEGF) mediated angiogenesis. The correlation of Caveolin-1 expression and angiogenesis is not yet elucidated in osteosarcoma. This study aimed to investigate the expression levels of Caveolin-1 and VEGF in osteosarcoma and their associations with clinicopathological data. This study included 66 formalin-fixed and paraffin embedded osteosarcoma tissue samples. The expression levels of Caveolin-1 and VEGF were assessed by immunohistochemistry. Then associations with clinicopathological variables and the correlation between both markers were evaluated statistically. We also investigated the expression of Caveolin-1 and VEGF values in gene microarrays of osteosarcoma patients and cell lines by using GEO data sets on https://www.ncbi.nlm.nih.gov. Caveolin-1 and VEGF were expressed in 19.6% and 77.3%, respectively. Caveolin-1 expression was associated positively with osteoblastic histological subtype (P < 0.0001). VEGF expression showed positive association with patient age, histological grade and clinical stage (P = 0.031, P = 0.024 and P < 0.001; respectively). An inverse correlation between Caveolin-1 and VEGF expressions in osteosarcoma was found (r = 0.2 P = 0.04). In silico analysis of Caveolin-1 and VEGF expression supported our results. Our results suggest that Caveolin-1 may act as a tumor suppressor in osteosarcoma. Down-regulation of Caveolin-1 can be used as an indicator for poor prognosis in osteosarcoma patients. Meanwhile, overexpression of VEGF is a predictor of pulmonary metastasis and poor prognosis.

MicroRNA-Based Diagnosis and Treatment of Metastatic Human Osteosarcoma

Osteosarcoma is a malignant tumor of the bones that commonly occurs in young individuals. The 5-year survival rate of osteosarcoma patients is 60-70%. Metastasis to the lungs leads to death in 30-40% of osteosarcoma patients. Therefore, the development of effective strategies for early detection and treatment of this disease are important to improve the survival of osteosarcoma patients. However, metastatic markers for osteosarcoma and molecules that might be targeted for the treatment of metastatic osteosarcoma have not been identified yet. Therefore, the mechanism of metastasis to the lungs needs to be explored from a novel viewpoint. Recently, the aberrant expression of microRNAs (miRNAs) has been reported to be involved in the carcinogenesis and cancer progression of many cancers. Furthermore, miRNAs in the blood have been reported to show an aberrant expression unique to several cancers. Therefore, miRNAs are gaining attention as potential diagnostic markers for cancers. On the other hand, normalizing the dysregulated expression of miRNAs in cancer cells has been shown to alter the phenotype of cancer cells, and thus treatment strategies targeting miRNAs are also being considered. This review summarizes the abnormality of miRNA expression associated with the metastasis of osteosarcoma and describes the present situation and issues regarding the early diagnosis and development of treatment strategies for metastatic osteosarcoma based on the current understanding of this disease.

Identification of Prognostic and Predictive Osteosarcoma Biomarkers

Both adolescents and children suffer from osteosarcoma, localized in the metaphysis of the long bones. This is the most common primary high-grade bone tumor in this patient group. Early tumor detection is the key to ensuring effective treatment. Improved osteosarcoma outcomes in clinical trials have been contingent on biomarker discovery and an evolving understanding of molecules and their complex interactions. In this review, we present a short overview of biomarkers for osteosarcoma, and highlight advances in osteosarcoma-related biomarker research. Many studies show that several biomarkers undergo critical changes with osteosarcoma progression. Growing knowledge about osteosarcoma-related markers is expected to positively impact the development of therapeutics for osteosarcoma, and ultimately of clinical care. It has also become important to develop new biomarkers, which can identify vulnerable patients who should be treated with more intensive and aggressive therapy after diagnosis.

Efficacy and safety of regorafenib in adult patients with metastatic osteosarcoma: a non-comparative, randomised, double-blind, placebo-controlled, phase 2 study

BACKGROUND

Regorafenib has proven activity in patients with pretreated gastrointestinal stromal tumours and colorectal and hepatocellular carcinoma. We designed REGOBONE to assess the efficacy and safety of regorafenib for patients with progressive metastatic osteosarcoma and other bone sarcomas. This trial comprised four parallel independent cohorts: osteosarcoma, Ewing sarcoma, chondrosarcoma, and chordoma. In this Article, we report the results of the osteosarcoma cohort.

METHODS

In this non-comparative, double-blind, placebo-controlled, phase 2 trial, patients aged 10 years or older with histologically confirmed osteosarcoma whose disease had progressed after treatment with one to two previous lines of chemotherapy for metastatic disease and an Eastern Cooperative Oncology Group performance status of 0 or 1 were enrolled. Patients were randomly assigned (2:1) to receive either oral regorafenib (160 mg/day, for 21 of 28 days) or matching placebo. Patients in both groups also received best supportive care. Randomisation was done using a web-based system and was stratified (permuted block) by age at inclusion (<18 vs ≥18 years old). Investigators and patients were masked to treatment allocation. Patients in the placebo group, after centrally confirmed progressive disease, could cross over to receive regorafenib. The primary endpoint was the proportion of patients without disease progression at 8 weeks. Analyses were done by modified intention to treat (ie, patients without any major entry criteria violation who initiated masked study drug treatment were included). All participants who received at least one dose of study drug were included in the safety analyses. This study is registered with ClinicalTrials.gov, number NCT02389244, and the results presented here are the final analysis of the osteosarcoma cohort (others cohorts are ongoing).

FINDINGS

Between Oct 10, 2014, and April 4, 2017, 43 adult patients were enrolled from 13 French comprehensive cancer centres. All patients received at least one dose of assigned treatment and were evaluable for safety; five patients were excluded for major protocol violations (two in the placebo group and three in the regorafenib group), leaving 38 patients who were evaluable for efficacy (12 in the placebo group and 26 in the regorafenib group). 17 of 26 patients (65%; one-sided 95% CI 47%) in the regorafenib group were non-progressive at 8 weeks compared with no patients in the placebo group. Ten patients in the placebo group crossed over to receive open-label regorafenib after centrally confirmed disease progression. 13 treatment-related serious adverse events occurred in seven (24%) of 29 patients in the regorafenib group versus none of 14 patients in the placebo group. The most common grade 3 or worse treatment-related adverse events during the double-blind period of treatment included hypertension (in seven [24%] of 29 patients in the regorafenib group vs none in the placebo group), hand-foot skin reaction (three [10%] vs none), fatigue (three [10%] vs one [3%]), hypophosphataemia (three [10%] vs none), and chest pain (three [10%] vs none). No treatment-related deaths occurred.

INTERPRETATION

Regorafenib demonstrated clinically meaningful antitumour activity in adult patients with recurrent, progressive, metastatic osteosarcoma after failure of conventional chemotherapy, with a positive effect on delaying disease progression. Regorafenib should be further evaluated in the setting of advanced disease as well as potentially earlier in the disease course for patients at high risk of relapse. Regorafenib might have an important therapeutic role as an agent complementary to standard cytotoxic chemotherapy in the therapeutic armamentarium against osteosarcoma.

FUNDING

Bayer HealthCare.

Prognostic impact of blood and urinary angiogenic factor levels at diagnosis and during treatment in patients with osteosarcoma: a prospective study

Background

Angiogenesis is essential for the progression and metastatic spread of solid tumours. Expression of vascular endothelial growth factor (VEGF) has been linked to poor survival among osteosarcoma patients but the clinical relevance of monitoring blood and urine angiogenic factors is uncertain. The aim of this study was to determine the prognostic significance of blood VEGF and blood and urinary basic fibroblast growth factor (bFGF) levels in osteosarcoma patients, both at diagnosis and during treatment.

Methods

Patients with localised or metastatic osteosarcoma enrolled in OS2005 and OS2006 studies between 2005 and 2011 were prospectively included in this study. VEGF and bFGF levels in serum and plasma and bFGF levels in urine were measured by ELISA at diagnosis, before surgery, and at the end of treatment. Endpoints considered for the prognostic analysis were histological response, progression-free and overall survival. Kruskal-Wallis tests were used to compare the distribution of baseline biomarker values across the different subgroups, and paired sample Wilcoxon rank tests were used to analyze changes over time. Association between biomarker levels and outcomes were assessed in multivariable models (logistic regression for histologic response, and Cox models for survival).

Results

Samples were available at diagnosis for 269 patients (54% males; age ≤ 18 years: 73%; localised disease in 68%, doubtful lung lesions in 17%, and metastases in 15%). High serum VEGF and bFGF levels were observed in respectively 61% and 51% of patients. Serum and plasma VEGF values were not strongly correlated with one another (r = 0.53). High serum and plasma VEGF levels were significantly more frequent in patients with large tumours (≥10 cm; p = 0.003 and p = 0.02, respectively). VEGF levels fell significantly during pre-operative chemotherapy (p < 0.0001). No significant correlation was found between this variation and either the histological response, progression-free survival or overall survival (p = 0.26, p = 0.67, and p = 0.87, respectively). No significant association was found between blood or urinary bFGF levels and clinical characteristics, histological response, or survival.

Conclusions

Levels of VEGF and bFGF angiogenic factors are high in most osteosarcoma patients, but have no significant impact on response to chemotherapy or outcome in this large prospective series.

OS 2006 trial registration number

clinicaltrials.gov NCT00470223; date of registration: May 3th 2007.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-017-3409-z) contains supplementary material, which is available to authorized users.

Docetaxel, bevacizumab, and gemcitabine for very high risk sarcomas in adolescents and young adults: A single-center experience

BACKGROUND

Adolescent and young adult (AYA) patients with very high risk sarcomas have poor outcomes and are in need of novel therapies.

PROCEDURE

From January 2005 to February 2016, we retrospectively identified all AYA patients with relapsed or metastatic high-grade sarcomas, who were treated with at least one cycle of docetaxel (T), bevacizumab (A), and gemcitabine (G) (TAG ; T = 100 mg/m² Day 8, A = 15 mg/kg Day 1, G = 1,000 mg/m² Days 1 and 8).

RESULTS

Fourteen patients, median age of 20 (15-30), received a total of 80 cycles of TAG, and were followed for a median of 83 months. Diagnosis included osteosarcoma (OST; 8), Ewing sarcoma (3), and soft tissue sarcoma (3). Five of 14 patients achieved clinical remission (CR), 3 had partial responses (PR), 3 had stable disease (SD), and 3 had progressive disease (PD). The median progression-free survival and overall survival were 7 and 19 months, respectively. The objective response rate (CR + PR) and tumor control rate (CR + PR + SD) were 57% and 79%, respectively, with two patients alive after 5 years; toxicities included thrombocytopenia, neutropenia, and capillary leak syndrome.

CONCLUSIONS

Our study builds on previous studies utilizing TAG in adult leiomyosarcoma (LMS) by focusing on AYA, non-LMS sarcomas, especially OST. Our experience suggests that TAG is well tolerated and has activity in very high risk sarcomas in AYA.

Prospective Preliminary In Vitro Investigation of a Magnetic Iron Oxide Nanoparticle Conjugated with Ligand CD80 and VEGF Antibody As a Targeted Drug Delivery System for the Induction of Cell Death in Rodent Osteosarcoma Cells

Target drug deliveries using nanotechnology are a novel consideration in the treatment of cancer. We present herein an in vitro mouse model for the preliminary investigation of the efficacy of an iron oxide nanoparticle complex conjugated to vascular endothelial growth factor (VEGF) antibody and ligand cluster of differentiation 80 (CD80) for the purpose of eventual translational applications in the treatment of human osteosarcoma (OSA). The 35 nm diameter iron oxide magnetic nanoparticles are functionalized with an n-hydroxysuccinimide biocompatible coating and are conjugated on the surface to proteins VEGF antibody and ligand CD80. Combined, these proteins have the ability to target OSA cells and induce apoptosis. The proposed system was tested on a cancerous rodent osteoblast cell line (ATCCTM^NPO CRL-2836) at four different concentrations (0.1, 1.0, 10.0, and 100.0 μg/mL) of ligand CD80 alone, VEGF antibody alone, and a combination thereof (CD80+VEGF). Systems were implemented every 24 h over different sequential treatment timelines: 24, 48, and 72 h, to find the optimal protein concentration required for a reduction in cell proliferation. Results demonstrated that a combination of ligand CD80 and VEGF antibody was consistently most effective at reducing aberrant osteoblastic proliferation for both the 24- and 72-h timelines. At 48 h, however, an increase in cell proliferation was documented for the 0.1 and 1 μg/mL groups. For the 24- and 72-h tests, concentrations of 1.0 μg/mL of CD80+VEGF and 0.1 μg/mL of VEGF antibody were most effective. Concentrations of 10.0 and 100.0 μg/mL of CD80+VEGF reduced cell proliferation, but not as remarkably as the 1.0 μg/mL concentration. In addition, cell proliferation data showed that multiple treatments (72-h test) induced cell death in the osteoblasts better than a single treatment. Future targeted drug delivery system research includes trials in OSA cell lines from greater phylum species having spontaneous OSA, such as the dog, and on a human OSA cell line model.

Indian data on bone and soft tissue sarcomas: A summary of published study results

Bone sarcomas are rare tumors, approximating 0.2% of all cancers, with osteosarcoma (OGS), chondrosarcoma, and Ewing sarcoma being the most common cancers in this subset. The formation of disease management groups/clinics focused on sarcomas has resulted in better understanding and management of these uncommon tumors. Multiple large-scale retrospective data from Tata Memorial Hospital (TMH) and All India Institute of Medical Sciences have reported outcomes comparable to Western data in the field of OGS and Ewing sarcoma, with interesting prognostic factors identified for further evaluation. Soft tissue sarcomas are a rare heterogeneous group of tumors, more than 50 different tumor entities. The common subtypes identified in India include Ewing sarcoma and synovial sarcoma. Valuable work regarding brachytherapy has been done by radiation oncologists from the TMH, especially in pediatric patients.

Bone Sarcomas in Pediatrics: Progress in Our Understanding of Tumor Biology and Implications for Therapy

The pediatric bone sarcomas osteosarcoma and Ewing sarcoma represent a tremendous challenge for the clinician. Though less common than acute lymphoblastic leukemia or brain tumors, these aggressive cancers account for a disproportionate amount of the cancer morbidity and mortality in children, and have seen few advances in survival in the past decade, despite many large, complicated, and expensive trials of various chemotherapy combinations. To improve the outcomes of children with bone sarcomas, a better understanding of the biology of these cancers is needed, together with informed use of targeted therapies that exploit the unique biology of each disease. Here we summarize the current state of knowledge regarding the contribution of receptor tyrosine kinases, intracellular signaling pathways, bone biology and physiology, the immune system, and the tumor microenvironment in promoting and maintaining the malignant phenotype. These observations are coupled with a review of the therapies that target each of these mechanisms, focusing on recent or ongoing clinical trials if such information is available. It is our hope that, by better understanding the biology of osteosarcoma and Ewing sarcoma, rational combination therapies can be designed and systematically tested, leading to improved outcomes for a group of children who desperately need them.

Prognostic value of tumor suppressors in osteosarcoma before and after neoadjuvant chemotherapy

Background

Primary bone cancers are among the deadliest cancer types in adolescents, with osteosarcomas being the most prevalent form. Osteosarcomas are commonly treated with multi-drug neoadjuvant chemotherapy and therapy success as well as patient survival is affected by the presence of tumor suppressors. In order to assess the prognostic value of tumor-suppressive biomarkers, primary osteosarcoma tissues were analyzed prior to and after neoadjuvant chemotherapy.

Methods

We constructed a tissue microarray from high grade osteosarcoma samples, consisting of 48 chemotherapy naïve biopsies (BXs) and 47 tumor resections (RXs) after neoadjuvant chemotherapy. We performed immunohistochemical stainings of P53, P16, maspin, PTEN, BMI1 and Ki67, characterized the subcellular localization and related staining outcome with chemotherapy response and overall survival. Binary logistic regression analysis was used to analyze chemotherapy response and Kaplan-Meier-analysis as well as the Cox proportional hazards model was applied for analysis of patient survival.

Results

No significant associations between biomarker expression in BXs and patient survival or chemotherapy response were detected. In univariate analysis, positive immunohistochemistry of P53 (P = 0.008) and P16 (P16; P = 0.033) in RXs was significantly associated with poor survival prognosis. In addition, presence of P16 in RXs was associated with poor survival in multivariate regression analysis (P = 0.003; HR = 0.067) while absence of P16 was associated with good chemotherapy response (P = 0.004; OR = 74.076). Presence of PTEN on tumor RXs was significantly associated with an improved survival prognosis (P = 0.022).

Conclusions

Positive immunohistochemistry (IHC) of P16 and P53 in RXs was indicative for poor overall patient survival whereas positive IHC of PTEN was prognostic for good overall patient survival. In addition, we found that P16 might be a marker of osteosarcoma chemotherapy resistance. Therefore, our study supports the use of tumor RXs to assess the prognostic value of biomarkers.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1397-4) contains supplementary material, which is available to authorized users.

The growth and aggressive behavior of human osteosarcoma is regulated by a CaMKII-controlled autocrine VEGF signaling mechanism

Osteosarcoma (OS) is a hyperproliferative malignant tumor that requires a high vascular density to maintain its large volume. Vascular Endothelial Growth Factor (VEGF) plays a crucial role in angiogenesis and acts as a paracrine and autocrine agent affecting both endothelial and tumor cells. The alpha-Ca²⁺/Calmodulin kinase two (α-CaMKII) protein is an important regulator of OS growth. Here, we investigate the role of α-CaMKII-induced VEGF in the growth and tumorigenicity of OS. We show that the pharmacologic and genetic inhibition of α-CaMKII results in decreases in VEGF gene expression (50%) and protein secretion (55%), while α- CaMKII overexpression increases VEGF gene expression (250%) and protein secretion (1,200%). We show that aggressive OS cells (143B) express high levels of VEGF receptor 2 (VEGFR-2) and respond to exogenous VEGF (100nm) by increasing intracellular calcium (30%). This response is ameliorated by the VEGFR inhibitor CBO-P11, suggesting that secreted VEGF results in autocrine stimulated α-CaMKII activation. Furthermore, we show that VEGF and α-CaMKII inhibition decreases the transactivation of the HIF-1α and AP-1 reporter constructs. Additionally, chromatin immunoprecipitation assay shows significantly decreased binding of HIF-1α and AP-1 to their responsive elements in the VEGF promoter. These data suggest that α-CaMKII regulates VEGF transcription by controlling HIF-1α and AP-1 transcriptional activities. Finally, CBO-P11, KN-93 (CaMKII inhibitor) and combination therapy significantly reduced tumor burden in vivo. Our results suggest that VEGF-induced OS tumor growth is controlled by CaMKII and dual therapy by CaMKII and VEGF inhibitors could be a promising therapy against this devastating adolescent disease.

Correlation between the expression of vegf and survival in osteosarcoma

Objective:

To present a series of 50 consecutive patients with non-metastatic extremity osteosarcoma, and attempt to correlate expression of the vascular endothelial growth factor (VEGF) protein in biopsy tissue to their prognosis regarding overall survival, disease-free survival and local recurrence.

Methods:

Fifty cases of non-metastatic osteosarcoma of the extremities treated between 1986 and 2006 at Instituto de Ortopedia e Traumatologia da Universidade de São Paulo, São Paulo, Brasil, were evaluated regarding expression of the VEGF protein. There were 19 females and 31 males. The mean age was 16 years old (range 5-28 years old) and the mean follow-up was 60.6 months (range 25-167 months). The variables studied were age, gender, anatomic location, type of surgery, surgical margins, tumor size, post chemotherapy necrosis, local recurrence, pulmonary metastasis and death.

Results:

Thirty-six patients showed VEGF expression on 30% or less cells (low), and the remaining 14 cases had VEGF expression above 30% (high). Among the 36 patients with low VEGF expression, nine developed pulmonary metastasis and four died (11.1%). Among the 14 patients with high VEGF expression, six developed pulmonary metastasis and three died (21.4%).

Conclusion:

There was no statistically significant correlation between the expression of VEGF and any of the variables studied. Level of Evidence IV, Therapeutic Study.

Survivin and vascular endothelial growth factor are associated with spontaneous pulmonary metastasis of osteosarcoma: Development of an orthotopic mouse model

The high rate of pulmonary metastases of osteosarcoma (OS) presents a therapeutic challenge in the field of orthopedics. Therefore, there is a marked requirement to establish a spontaneous pulmonary metastasis animal model of OS, within which potential antitumor agents may be evaluated for their ability to inhibit the growth and pulmonary metastasis of OS, as well as to identify potentially associated biomarkers of OS metastasis. In the present study, rodent OS cells (UMR106-01) were injected into the right tibia of athymic nude mice. The mice were sacrificed weekly by cervical dislocation at one to five weeks following inoculation. The orthotopic mice developed tumor masses in the right tibia one week following inoculation. At three weeks, multiple nodules were observed in the lungs. The expression of survivin and vascular endothelial growth factor (VEGF) was analyzed in the tumors and lungs via immunohistochemistry. The positive expression of survivin and VEGF was identified in the local tumor and lung tissue of the orthotopic mice, however was not observed in the tissues of the healthy control mice. The orthotopic model established in the current study presents a valuable tool for the investigation of factors that promote or inhibit OS growth and/or metastasis. In addition, it was identified that survivin and VEGF may be significant in the lung metastasis of OS.

Impact of vascular endothelial growth factor expression on overall survival in patients with osteosarcoma: a meta-analysis

Osteosarcoma is the most common primary malignant bone tumor of childhood. Vascular endothelial growth factor (VEGF) expression has been implicated in tumor development and progression of osteosarcoma, but previous studies investigating the impact of VEGF expression on overall survival in patients with osteosarcoma report conflicting findings. A meta-analysis of published studies was performed. The pooled hazard ratio (HR) with its 95% confidence interval (95% CI) was used to assess the impact of VEGF expression on overall survival in patients with osteosarcoma. Nine studies with a total of 432 osteosarcoma patients were included into this meta-analysis. There was no between-study heterogeneity among those nine studies (I (2) = 0.0%). Overall, high VEGF expression was obviously associated with poorer overall survival (HR = 1.68, 95% CI 1.33-2.12, P < 0.001). Sensitivity analysis performed by excluding single study in turns showed the pooled estimate was stable. Egger's test also did not suggest evidence for publication bias (P = 0.216). Therefore, this meta-analysis suggests that VEGF expression has an important impact on overall survival in patients with osteosarcoma and high VEGF expression is associated with poorer overall survival.

Apurinic/apyrimidinic endonuclease 1 induced upregulation of fibroblast growth factor 2 and its receptor 3 induces angiogenesis in human osteosarcoma cells

Tumor angiogenesis contributes to inferior prognosis in osteosarcoma. Apurinic/apyrimidinic endonuclease 1 (APE1) and fibroblast growth factor 2 (FGF2) and its receptor 3 (FGFR3) signaling pathway plays an important role in the angiogenic process. In this study we observed that high expression of APE1, FGF2 and FGFR3, and microvessel density are positively correlated with poor prognosis of osteosarcoma patients. Furthermore, the Cox model showed that the tumor size, FGF2 and its receptor 3 (FGFR3), and microvessel density were adverse prognostic factors. Based on our clinical data, and the fact that APE1 is involved in tumor angiogenesis, we hypothesize that it is very likely that APE1 may indirectly promote angiogenesis by upregulating fibroblast FGF2 and FGFR3. Our preliminary data show small interfering RNA-mediated silence of APE1 experiments, which further supports this hypothesis. APE1-small interfering RNA significantly inhibited tumor angiogenesis by downregulating in vitro expression of FGF2 and FGFR3 in human umbilical vein endothelial cells in Matrigel tube formation assay, and further inhibited tumor growth in vivo in a mouse xenograft model. Thus, the proposed APE1-FGF2 and FGFR3 pathway may provide a novel mechanism for regulation of FGF2 and FGFR3 by APE1 in tumor angiogenesis.

Review of management issues in relapsed osteosarcoma

Osteosarcoma is the most common primary malignant bone tumor in children and adolescents. With combined modality treatment long-term survival rate for localized disease is near 70%. Thirty percent of patients relapse with lung as the commonest site. Surgery is the treatment of choice for relapsed patients whenever possible. Addition of chemotherapy to surgery provides survival benefit in patients not achieving second surgical remission. Even patients with multiple lung recurrences can be cured with repeated thoracotomies. Disease-free interval and complete surgical resection are the main prognostic factor for post-relapse survival.

A systematic review of vascular endothelial growth factor expression as a biomarker of prognosis in patients with osteosarcoma

Vascular endothelial growth factor (VEGF) plays an important role in the tumor angiogenesis, and its expression has been supposed to be a biomarker of prognosis in patients with osteosarcoma. There are many studies assessing the prognostic role of VEGF expression in osteosarcoma, and no consistent outcomes are reported. To provide a comprehensive assessment of the prognostic role of VEGF expression, we performed a systematic review and meta-analysis of published studies. We assessed the effect of VEGF expression on the overall survival rate and the disease-free survival rate by calculating the pooled odds ratio (OR) with corresponding 95 % confidence interval (95 %CI). Finally, 12 studies with a total of 559 osteosarcoma patients were included into the systematic review and meta-analysis. Compared with osteosarcoma patients with low or negative VEGF expression, patients with high VEGF expression were obviously associated with lower disease-free survival (OR=0.25, 95 %CI 0.11-0.58, P=0.001, I (2) =56.4 %). In addition, patients with high VEGF expression were obviously associated with lower overall survival (OR=0.22, 95 %CI 0.13-0.35, P<0.001, I (2) =0.0 %). Therefore, the findings from this systematic review suggest that VEGF expression is an effective biomarker of prognosis in patients with osteosarcoma.

IL-17A/IL-17RA interaction promoted metastasis of osteosarcoma cells

Osteosarcoma (OS) is the most common human primary malignant bone tumor in children and young adults with poor prognosis because of their high metastatic potential. Identification of key factors that could regulate the aggressive biologic behavior of OS, particularly with respect to metastasis, would be necessary if significant improvements in therapeutic outcome are to occur. In this study, we carefully evaluated the potential role of IL-17A/IL-17RA interaction in metastasis of OS. We found that serum IL-17A was higher in OS patients with metastasis and was associated with their clinical stage. The elevated expression of IL-17RA was observed in tumor tissue from OS patients with metastasis. Of note, we showed that IL-17A could promote the metastasis of U-2 OS cells which expression high IL-17RA, but not MG63 cells which expression low IL-17RA. Further, we revealed that downregulation of IL-17RA in U-2 cells could abrogated the enhanced metastasis induced by IL-17A, while upregulation of IL-17RA in MG63 cells could elevate their response to IL-17A and exerted enhanced metastasis. We observed that IL-17A/IL-17RA interaction promoted the expression of VEGF, MMP9 and CXCR4 in OS cells, which might partly explain the enhanced metastasis of OS cells. Furthermore, we showed that Stat3 activity was crucial for IL-17A/IL-17RA interaction to promote OS metastasis. Finally, we confirmed that IL-17A/IL-17RA interaction promoted the metastasis of OS in nude mice. Our findings might provide a mechanistic explanation for metastasis of OS in vivo, and suggested that targeting IL-17A signaling was a novel promising strategy to treat patients with OS.

Bone sarcomas: from biology to targeted therapies

Primary malignant bone tumours, osteosarcomas, and Ewing sarcomas are rare diseases which occur mainly in adolescents and young adults. With the current therapies, some patients remain very difficult to treat, such as tumour with poor histological response to preoperative CT (or large initial tumour volume for Ewing sarcomas not operated), patients with multiple metastases at or those who relapsed. In order to develop new therapies against these rare tumours, we need to unveil the key driving factors and molecular abnormalities behind the malignant characteristics and to broaden our understanding of the phenomena sustaining the metastatic phenotype and treatment resistance in these tumours. In this paper, starting with the biology of these tumours, we will discuss potential therapeutic targets aimed at increasing local tumour control, limiting metastatic spread, and finally improving patient survival.

Gemcitabine, docetaxel, and bevacizumab in relapsed and refractory pediatric sarcomas

BACKGROUND

The outcome for patients with relapsed and refractory pediatric sarcomas remains dismal. Novel agents are needed to improve overall survival in these patients.

OBSERVATIONS

We present 3 patients with relapsed/refractory sarcomas treated with gemcitabine, docetaxel, and bevacizumab in 3-week cycles. The combination was well tolerated with minimal toxicity. Two patients had a partial response and the third patient had stable disease for >6 months.

CONCLUSIONS

These results are limited by small patient numbers but this strategy should be evaluated in prospective clinical trials.

VEGF expression in residual tumor cells in orbital retinoblastoma (IRSS stage III) treated with NACT: a prospective study

We prospectively evaluated vascular endothelial growth factor (VEGF) expression by immunohistochemistry in 22 consecutive IRSS stage III retinoblastoma patients who underwent enucleation after neoadjuvant chemotherapy (NACT). Positive VEGF expression was observed in 6/22 (27.3%) patients. VEGF expression was associated with local progression on MRI prior to enucleation (P = 0.004), pathological scleral (P = 0.023), and extra-scleral tumor extension (P = 0.009). EFS for VEGF positive and negative patients was 0% and 56.25%, respectively (P = 0.0002). OS for VEGF positive patients was 33.33% and 54.69% for VEGF negative patients (P = 0.207). Thus, VEGF in residual tumor cells post-NACT may represent poor response to NACT, potential for local invasion, and inferior outcome.

Experimental study on inhibitory effects of diallyl sulfide on growth and invasion of human osteosarcoma MG-63 cells

The inhibitory effects of diallyl sulfide (DAS) derived from allicin on in vitro and in vivo proliferation of human osteosarcoma MG-63 cells and the action mechanism, and the influence of DAS on invasive capability of MG-63 cells were investigated in order to search for the novel medicines for osteosarcoma. In the in vitro experiment, MG-63 cells were treated with different concentrations of DSA, and the morphological changes of MG-63 cells were observed under an inverted phase microscope. MTT method was used to assay the proliferation of MG-63 cells. Semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) was used to detect the VEGF mRNA expression level in MG-63 cells. By using Transwell invasion assay, the influence of DAS on invasive ability of MG-63 cells was tested. In the in vivo experiment, the nude mice MG-63 cells tumor-bearing model was established, and different concentrations of DAS were injected beside the tumor. Twenty-one days after treatment, the mice were killed, the tumor size and tumor inhibition rate were calculated. The microvessel density (MVD) was determined by using immunohistochemistry. In the in vitro experiment, different concentrations of DAS could obviously inhibit proliferation of MG-63 cells in a time- and concentration-dependent manner. RT-PCR revealed that the expression levels of VEGF mRNA in DSA groups (different concentrations) were significant reduced as compared with those in control group (all P<0.05). Transwell invasion assay indicated that in 20 and 40 μg/mL DAS groups, the number of migratory cells was 91.4±8.3 and 81.8±7.4 respectively, which was significantly declined as compared with that in control group (150.4±14.7, both P<0.05). In the in vivo experiment, DAS could significantly suppress the growth of MG-63 tumor-bearing tissue. Immunohistochemistry demonstrated that different concentrations (20 and 40 μg/mL) of DAS could significantly decrease MVD of MG-63 tumor-bearing tissue (all P<0.05). It was suggested that DAS could inhibit the growth of MG-63 cells probably by suppressing the expression of VEGF mRNA.

Experimental study on inhibitory effects of diallyl sulfide on growth and invasion of human osteosarcoma MG-63 cells

Background. Allicin, the major component of freshly crushed garlic, is one of the most biologically active compounds of garlic; it has been reported to induce apoptosis in cancer cells; however, the mechanism by which allicin exerts its apoptotic effects is not fully understood. The aim of the present study was to further elucidate the apoptotic pathways induced by allicin in the human ovarian cancer cell line SKOV3. Methods. Cell proliferation and apoptosis were measured by cell-counting assay and flow cytometry analysis. Activation of the signaling pathway was screened by human phospho-kinase array analysis, and the activated pathway and its related proteins were further confirmed by western blot analysis. Results. Allicin induced SKOV3 cell apoptosis and JNK phosphorylation in a time- and dose-dependent manner, but these were significantly blocked by SP600125 (an inhibitor of JNK). The findings suggest that JNK phosphorylation is related to the action of allicin on SKOV3 cells. Furthermore, JNK activation induced Bcl-2 family activation, triggered mitochondria-mediated signaling pathways, and led to the translocation of a considerable amount of Bax and cytochrome c release. Conclusions. JNK activation and mitochondrial Bax translocation are involved in allicin-induced apoptosis in SKOV3 cells. Our data input new insights to the literature of allicin-induced apoptosis.

Of dogs and men: comparative biology as a tool for the discovery of novel biomarkers and drug development targets in osteosarcoma

The similarities between human and canine osteosarcoma with regard to histology, biological behavior and molecular genetic alterations suggest that the dog provides a supplementary model for the development and preclinical testing of novel therapeutics. Counter intuitively, careful examination of the differences between OS in the two species may also be rewarding in terms of increasing our understanding of the pathogenesis of this cancer. This review will discuss the arguments in favor of the "dog model" and outline how the evaluation of treatment strategies in dogs has indicated avenues for improvement of protocols for human patients.

Nucleotide excision repair gene variants and association with survival in osteosarcoma patients treated with neoadjuvant chemotherapy

The aim of this study was to investigate the role of common polymorphisms in the nucleotide excision repair pathway genes in the tumorigenesis of osteosarcoma and in the response to DNA damaging therapies, such as cisplatin-based neoadjuvant therapy. Excision repair cross-complementing (ERCC) group 2 (XPD; rs13181 and rs1799793), group 5 (XPG; rs17655) and group 1 (XPA; rs3212986 and rs11615) polymorphisms were analyzed in a group of 130 homogenously treated patients with high-grade osteosarcoma, for association with event-free survival (EFS), using the Kaplan-Meier plots and log-rank test. A positive association was observed between both XPD single-nucleotide polymorphisms and an increased EFS (hazards ratio (HR) = 0.34, 95% confidence interval (CI) 0.12-0.98 and HR = 0.19, 95% CI 0.05-0.77, respectively). We had also performed a case-control study for relative risk to develop osteosarcoma. Patients carrying at least one variant allele of XPD rs1799793 had a reduced risk of developing osteosarcoma, compared with wild-type patients (odds ratio = 0.55, 95% CI 0.36-0.84). This study suggests that XPD rs1799793 could be a marker of osteosarcoma associated with features conferring either a better prognosis or a better outcome after platinum therapy, or both.

Expression of molecular markers in the tumor and survival prognosis in osteosarcoma

Immunohistochemical study of p53, VEGF, Flt-1/VEGFR1 Ab-1, EGFR, HER-2/neu, Bax, and Cox-2 expression in osteosarcomas was carried out in 40 patients aged 16-70 years. Expression of p53 was detected in 27.5% tumors, VEGF in 15%, Flt-1/VEGFR1 Ab-1 in 97.5%, EGFR in 52.5%, HER-2/neu in 32.5%, Bax in 77.8%, and Cox-2 in 32.3% tumors. Multifactorial analysis showed that the expression of HER-2/neu (p=0.004), p53 (p=0.01), and Cox-2 (p=0.04) in osteosarcomas significantly correlated with unfavorable prognosis for overall survival, while HER-2/neu (p=0.02) and Cox-2 (p=0.003) with relapse-free survival. Analysis of HER-2/neu, p53, and Cox-2 expression in the primary tumor should be taken into consideration in the treatment of patients with osteosarcoma.

Peritumoral neutrophils link inflammatory response to disease progression by fostering angiogenesis in hepatocellular carcinoma

BACKGROUND & AIMS

Substantial evidence indicates that inflammation is a critical component of tumor progression. Hepatocellular carcinoma (HCC) is usually derived from inflamed cirrhotic liver with extensive leukocyte infiltration. Neutrophils are the common inflammatory infiltrate in tumors, but their nature and regulation in human cancers remain elusive.

METHODS

A total of 238 HCC patients were enrolled randomly. Immunohistochemistry and SuperArray Real-Time PCR were used to analyze the distribution and clinical relevance of neutrophils in different microanatomical areas. The regulation and function of neutrophils were assessed by both in vitro and in vivo studies.

RESULTS

Neutrophils were enriched predominantly in peritumoral stroma of HCC tissues and their levels could serve as a powerful predictor for poor survival in HCC patients. Proinflammatory IL-17 is a critical mediator of the recruitment of neutrophils into peritumoral stroma of HCC tissues by epithelial cell-derived CXC chemokines. The accumulated peritumoral neutrophils were the major source of matrix metalloproteinase-9 in HCC tissues; this secreted protein stimulated proangiogenic activity in hepatoma cells. Accordingly, high infiltration of peritumoral neutrophils was positively correlated with angiogenesis progression at tumor-invading edge of HCC patients. Furthermore, we found that selective depletion of neutrophils effectively inhibited tumor angiogenesis and growth, in vivo.

CONCLUSIONS

These data provide direct evidence supporting the critical role of neutrophils in human tumor progression and reveal a fine-tuned collaborative action between cancer cells and immune cells in distinct tumor milieu, which reroutes the inflammatory response into a tumor-promoting direction.

Prognostic and predictive biomarkers of canine osteosarcoma

Canine osteosarcoma (OS) is an aggressive tumour that accounts for approximately 90% of primary bone tumours in the dog. Although the standard treatments (including limb amputation/sparing, chemotherapy and palliative radiotherapy) have significantly increased survival rates, almost 90% of animals will eventually develop predominantly pulmonary metastases. Despite advances in various therapies, prognosis remains poor, with median survival times ranging from 3 months to 1 year and <20% of dogs survive for >2 years following diagnosis. Various clinical and epidemiological markers have facilitated decision-making with respect to therapy but no single molecular biomarker has been shown to enhance prediction of disease progression. The publication of the canine genome in 2005 raised the possibility of increasing understanding of the genetic mechanisms underpinning canine OS. This review explores the use of biomarkers within the multi-disciplinary management of dogs with OS, and highlights the few known, potential prognostic/predictive molecular markers including their potential value as 'bridging biomarkers' for human OS. Although high-throughput profiling of canine OS remains in its infancy, research within the next decade using leading-edge screening technologies has the potential to identify biomarkers that may enhance diagnostic and prognostic accuracy and result in more effective, individually tailored, treatment and management protocols for affected dogs.

Comparative proteomics analysis of human osteosarcomas and benign tumor of bone

We conducted comparative proteomic analysis of osteosarcoma, with hopes of identifying the specific protein markers of osteosarcoma and improve the understanding of tumorigenesis and progression of osteosarcoma. Proteins extracted from osteosarcoma tissue and benign bone tumors, including osteoblastoma, chondroblastoma, and giant cell tumor of bone, were examined using two-dimensional gel electrophoresis followed by mass spectrometry analysis and database searches. We also validated the expression levels of interesting proteins by Western blotting assay and immunohistochemical staining. Intensity alterations of 30 spots were detected in osteosarcoma, and 18 of these spots were finally identified, including 12 up-regulated proteins and 6 down-regulated ones. The up-regulated proteins include VIM, TUBA1C, ZNF133, EZR, ACTG1, TF, and so on. The six down-regulated proteins include ADCY1, ATP5B, TUBB, RCN3, ACTB, and YWHAZ. Subsequent immunohistochemical staining and Western blotting assay for TUBA1C and ZNF133 in osteosarcoma samples confirmed the observation obtained by proteomic analysis. Our results suggest that these identified proteins may be potential biomarkers for osteosarcoma tumorigenesis and therapeutics. Aberrant expression of cytoskeletal- and microtubule-associated proteins in osteosarcoma may provide an advantage for tumor invasion and metastasis by affecting the stability of microtubule, which consequently influences the prognosis of patients.

Prognostic markers in osteosarcoma

Osteosarcoma is the most common bone tumor seen in the pediatric and adolescent age group. Survival rates in osteosarcoma have improved considerably from 20 to 65% since the 1980s with the advent of multiagent chemotherapy. Further improvement in survival has not been achieved owing to lack of well-validated prognostic markers and better therapeutic agents. Markers involved with angiogenesis, cell adhesion, apoptosis and cell cycle have been shown recently to play an important role in osteosarcoma growth, differentiation and metastasis. Over the coming years, the new molecular markers may be able not only to prognosticate osteosarcoma patients at baseline but also to serve as therapeutic targets and thereby improve survival rates further. Noninvasive imaging methods in osteosarcoma such as PET-CT and dynamic contrast enhanced and diffusion-weighted MRI hold a lot of promise as surrogate methods for prognostication and response assessment.