Osteogenic Sarcoma (osteosarcoma) is a bone forming cancer. It is the most frequent type of bone tumour and is most common between the ages of 15 to 25. Over 90% of tumours are located in the metaphysis (the growing ends of the bone), the most common sites are the bones around the knee which account for 80% of cases. Osteosarcomas vary greatly in radiological and pathological features and therefore needs careful diagnosis to differentiate this from other bone tumours. Most are high grade intramedullary osteosarcomas, about 5% are low grade lesions, some are secondary osteosarcomas (for example those caused by radiation therapy).
Figure 1. Radiograph showing an osteolytic and osteoblastic intra-medullary tumor characteristic of osteosarcoma. From Layfield J et al. Clin Med Pathol. 2008; 1: 55-59. Available under a Creative Commons CC-BY-3.0 license.
Bone Cancer Research Trust Information is reviewed by a panel of scientific and clinical experts, patients, parents/ carers, Further info. Overview of Osteosarcoma and the different types of the disease.
Mayo Clinic Dr. Carola Arndt discusses osteosarcoma which is one of the most common malignant tumors of bone in teenagers and young adults. She discusses diagnosis, evaluation, and treatment of osteosarcoma. Also mentions the Children's Oncology group and EURAMOS study. Mentions the multi-disciplinary approach at Mayo Clinic.
PubMed Central search for free-access publications about Osteosarcoma MeSH term: Osteosarcoma US National Library of Medicine PubMed has over 22 million citations for biomedical literature from MEDLINE, life science journals, and online books. Constantly updated.
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Tang YJ, Wang JL, Nong LG, et al. Associations of IL-27 polymorphisms and serum IL-27p28 levels with osteosarcoma risk. Medicine (Baltimore). 2014; 93(10):e56 [PubMed] Related Publications
Interleukin (IL)-27 is a novel cytokine secreted by stimulation of antigen-presenting cells. No previous studies currently reported the role of IL-27 in the carcinogenesis of osteosarcoma. We aimed to investigate the association of IL-27 polymorphisms and serum IL-27p28 with osteosarcoma risk in a Chinese population.One hundred and sixty osteosarcoma patients and 250 health controls were selected. IL-27 gene -964 A/G, 2905 T/G, and 4730 T/C polymorphisms were determined by using polymerase chain reaction-restriction fragment length polymorphism. Enzyme-linked immunosorbent assay were used to detect serum IL-27p28 levels.The serum IL-27p28 levels were significantly lower in osteosarcoma patients compared with those in controls (P < 0.01). Serum IL-27p28 levels in stages III-IV were lower than those in stages I-II of osteosarcoma (P < 0.05); similar results were also found in patients with metastasis, that is, patients with metastasis have higher IL-27p28 levels than those without metastasis (P < 0.05). There were no associations between genotype and allele frequencies of IL-27 -964 A/G, 2905 T/G, 4730 T/C, and the risk of osteosarcoma (P > 0.05). Stratification analysis also failed to show the associations between -964 A/G, 2905 T/G, and 4730 T/C polymorphisms and the clinical stage and metastasis of osteosarcoma (P > 0.05). Three possible haplotypes (ATT, GTT, and GGC) were identified, but no associations were found between them and the osteosarcoma risk (P > 0.05).This study indicates that the lower serum IL-27p28 levels may be associated with development and progression of osteosarcoma, but IL-27 gene -964 A/G, 2905 T/G, and 4730 T/C polymorphisms and their haplotypes are not associated with osteosarcoma risk.
Osteosarcoma is a malignant tumor that primarily affects the long bones but can also involve other bones in the body. It has a bimodal distribution with peaks in the second decade of life and late adulthood. This chapter will highlight the clinical presentation, diagnosis, and treatment of osteosarcoma.
Zhang Z, Zheng Y, Zhu R, et al. The ERK/eIF4F/Bcl-XL pathway mediates SGP-2 induced osteosarcoma cells apoptosis in vitro and in vivo. Cancer Lett. 2014; 352(2):203-13 [PubMed] Related Publications
The aim of this study is to assess the molecular foundation of anti-tumor activity of SGP-2 in osteosarcoma cells. SGP-2 significantly blocks cell proliferation in human osteosarcoma U2OS cell model and inhibits tumor growth without causing apparent toxicity effect in mouse sarcoma S-180 cell-derived tumor model. Moreover, SGP-2 induces intrinsic apoptosis including the activation of caspase-3/7/9, the loss of mitochondrial transmembrane potential (ΔΨm), and the release of cytochrome c from mitochondrion, controlled by the down-regulation of B-cell lymphoma-extra large (Bcl-XL). Further research reveals that SGP-2 inhibits the assembly of eukaryotic initiation factor 4F (eIF4F) complex which is responsible for the decline of Bcl-XL. Finally, extracellular-signal-regulated kinase (ERK) controls SGP-2 induced intrinsic apoptosis. Taken together, SGP-2 exerts anti-tumor effect through intrinsic apoptotic pathway controlled by ERK/eIF4F/Bcl-XL pathway.
BACKGROUND: To uncover the genes involved in the development of osteosarcoma (OS), we performed a meta-analysis of OS microarray data to identify differentially expressed genes (DEGs) and biological functions associated with gene expression changes between OS and normal control (NC) tissues. METHODS: We used publicly available GEO datasets of OS to perform a meta-analysis. We performed Gene Ontology (GO) enrichment analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis and Protein-Protein interaction (PPI) networks analysis. RESULTS: Eight GEO datasets, including 240 samples of OS and 35 samples of controls, were available for the meta-analysis. We identified 979 DEGs across the studies between OS and NC tissues (472 up-regulated and 507 down-regulated). We found GO terms for molecular functions significantly enriched in protein binding (GO: 0005515, P = 3.83E-60) and calcium ion binding (GO: 0005509, P = 3.79E-13), while for biological processes, the enriched GO terms were cell adhesion (GO:0007155, P = 2.26E-19) and negative regulation of apoptotic process (GO: 0043066, P = 3.24E-15), and for cellular component, the enriched GO terms were cytoplasm (GO: 0005737, P = 9.18E-63) and extracellular region (GO: 0005576, P = 2.28E-47). The most significant pathway in our KEGG analysis was Focal adhesion (P = 5.70E-15). Furthermore, ECM-receptor interaction (P = 1.27E-13) and Cell cycle (P = 4.53E-11) are found to be highly enriched. PPI network analysis indicated that the significant hub proteins containing PTBP2 (Degree = 33), RGS4 (Degree = 15) and FXYD6 (Degree = 13). CONCLUSIONS: Our meta-analysis detected DEGs and biological functions associated with gene expression changes between OS and NC tissues, guiding further identification and treatment for OS.
Takagi S, Takemoto A, Takami M, et al. Platelets promote osteosarcoma cell growth through activation of the platelet-derived growth factor receptor-Akt signaling axis. Cancer Sci. 2014; 105(8):983-8 [PubMed] Related Publications
The interactions of tumor cells with platelets contribute to the progression of tumor malignancy, and the expression levels of platelet aggregation-inducing factors positively correlate with the metastatic potential of osteosarcoma cells. However, it is unclear how tumor-platelet interaction contributes to the proliferation of osteosarcomas. We report here that osteosarcoma-platelet interactions induce the release of platelet-derived growth factor (PDGF) from platelets, which promotes the proliferation of osteosarcomas. Co-culture of platelets with MG63 or HOS osteosarcoma cells, which could induce platelet aggregation, enhanced the proliferation of each cell line in vitro. Analysis of phospho-antibody arrays revealed that co-culture of MG63 cells with platelets induced the phosphorylation of platelet derived growth factor receptor (PDGFR) and Akt. The addition of supernatants of osteosarcoma-platelet reactants also increased the growth of MG63 and HOS cells as well as the level of phosphorylated-PDGFR and -Akt. Sunitinib or LY294002, but not erlotinib, significantly inhibited the platelet-induced proliferation of osteosarcoma cells, indicating that PDGF released from platelets plays an important role in the proliferation of osteosarcomas by activating the PDGFR and then Akt. Our results suggest that inhibitors that specifically target osteosarcoma-platelet interactions may eradicate osteosarcomas.
Xing D, Qasem SA, Owusu K, et al. Changing prognostic factors in osteosarcoma: analysis of 381 cases from two institutions. Hum Pathol. 2014; 45(8):1688-96 [PubMed] Related Publications
Osteosarcoma occurs most commonly in children and young adults, with a historic second incidence peak in the elderly. Most studies have focused on those occurring in adolescence. Detailed information on descriptive features and prognostic factors in patients of different age groups is lacking. We analyzed 381 osteosarcomas diagnosed between 1973 and 2012 to identify factors significantly associated with survival in various age groups. The peak incidence was seen in patients age <25, followed by a steady incidence rate thereafter until the sixth decade, when it started to decline. In the early onset diseases, significant factors for recurrence-free survival (RFS) were tumor site and size; whereas those for overall survival (OS) were gender, tumor site, type, grade and size. In patients age 25 to 54, tumor type and grade were significant for RFS, and the pathologic type was significant for OS. In those age ≥55, race and tumor size were significant for RFS; tumor site and size were significant for OS. In multivariate analysis, tumor size remained significant for RFS; gender, tumor site and size maintained their significance for OS in patients age <25. While no independent factor was identified in patients age 25 to 54, tumor size remained significant for RFS in those age ≥55. Chemotherapy-induced tumor necrosis was a prognosticator for RFS in patients age 25 to 54 by univariate analysis, but not as an independent factor in any stratified age group. Our data indicate that the distinctive prognostic factors differed significantly among different age groups, thus providing a rationale for age-based management strategies.
Natural killer (NK) cells are lymphocytes of the innate immune system that have the ability to recognize malignant cells through detection of a variety of cell-surface indicators of stress and danger. Once activated through such recognition, NK cells release cytokines and induce target cell lysis through a variety of mechanisms. NK cells are increasingly recognized as important mediators of other immunotherapeutic modalities, including cytokines, antibodies, immunomodulators, and stem cell transplantation. Adoptive immunotherapies with NK cells are being tested in early-stage clinical trials, and recent advances in manipulating their number and function have caused a renewed emphasis on this cancer-fighting cell. In this chapter we address the evidence for NK cell recognition of osteosarcoma in vitro and in vivo, discuss new therapies that are directly or indirectly dependent on NK cell function, and describe potential approaches for manipulating NK cell number and function to enhance therapy against osteosarcoma.
DeRenzo C, Gottschalk S Genetically modified T-cell therapy for osteosarcoma. Adv Exp Med Biol. 2014; 804:323-40 [PubMed] Related Publications
T-cell immunotherapy may offer an approach to improve outcomes for patients with osteosarcoma, who fail current therapies. In addition, it has the potential to reduce treatment-related complications for all patients. Generating tumor-specific T cells with conventional antigen presenting cells ex vivo is time consuming and often results in T-cell products with a low frequency of tumor-specific T cells. In addition, the generated T cells remain sensitive to the immunosuppressive tumor microenvironment. Genetic modification of T cells is one strategy to overcome these limitations. For example, T cells can be genetically modified to render them antigen specific, resistant to inhibitory factors, or increase their ability to home to tumor sites. Most genetic modification strategies have only been evaluated in preclinical models, however early phase clinical trials are in progress. In this chapter we review the current status of gene-modified T-cell therapy with special focus on osteosarcoma, highlighting potential antigenic targets, preclinical and clinical studies, and strategies to improve current T-cell therapy approaches.
Meyers PA, Chou AJ Muramyl tripeptide-phosphatidyl ethanolamine encapsulated in liposomes (L-MTP-PE) in the treatment of osteosarcoma. Adv Exp Med Biol. 2014; 804:307-21 [PubMed] Related Publications
Bacille Calmette-Guerin (BCG) has been used for decades as an immune stimulant to treat cancer. Early work by Fidler and Kleinerman identified muramyl dipeptide (MDP) as a critical component of the BCG cell wall which retained most of the immunostimulatory properties of the native BCG. Addition of a peptide to MDP resulted in muramyl tripeptide (MTP) which allowed incorporation into liposomal membranes. The resulting pharmaceutical, liposomal muramyl tripeptide phosphatidyl ethanolamine (L-MTP-PE or mifamurtide) showed activity in preclinical models of human cancers. Phase I studies documented the safety of the compound for human administration. These trials did not reach a maximally tolerated dose (MTD), and the dose chosen for phase II trials was a biologically optimized dose, not an MTD. Phase II studies showed decreased risk of further recurrence in patients who received mifamurtide after surgical ablation of metastatic osteosarcoma. A phase III prospective randomized trial demonstrated a statistically significant reduction in the risk of death from osteosarcoma when MTP was added to systemic chemotherapy for the treatment of localized osteosarcoma. The same trial allowed treatment of patients who presented with initially metastatic disease. While the overall and event-free survival was improved in patients with metastatic osteosarcoma who received L-MTP-PE, the sample size was small and the improvement did not achieve conventional statistical significance. From 2008 to 2012, patients with metastatic and recurrent osteosarcoma were given L-MTP-PE in an expanded access trial, and the results suggest a decreased risk of subsequent recurrence and death with the inclusion of L-MTP-PE in the treatment strategy for these high-risk patients.
Anderson PM, Subbiah V, Rohren E Bone-seeking radiopharmaceuticals as targeted agents of osteosarcoma: samarium-153-EDTMP and radium-223. Adv Exp Med Biol. 2014; 804:291-304 [PubMed] Related Publications
Osteosarcoma is a cancer characterized by formation of bone by malignant cells. Routine bone scan imaging with Tc-99m-MDP is done at diagnosis to evaluate primary tumor uptake and check for bone metastases. At time of relapse the Tc-99m-MDP bone scan also provides a specific means to assess formation of bone by malignant osteosarcoma cells and the potential for bone-seeking radiopharmaceuticals to deliver radioactivity directly into osteoblastic osteosarcoma lesions. This chapter will review and compare a bone-seeking radiopharmaceutical that emits beta-particles, samarium-153-EDTMP, with an alpha-particle emitter, radium-223. The charged alpha particles from radium-223 have far more mass and energy than beta particles (electrons) from Sm-153-EDTMP. Because radium-223 has less marrow toxicity and more radiobiological effectiveness, especially if inside the bone forming cancer cell than samarium-153-EDTMP, radium-223 may have greater potential to become widely used against osteosarcoma as a targeted therapy. Radium-223 also has more potential to be used with chemotherapy against osteosarcoma and bone metastases. Because osteosarcoma makes bone and radium-223 acts like calcium, this radiopharmaceutical could possibly become a new targeted means to achieve safe and effective reduction of tumor burden as well as facilitate better surgery and/or radiotherapy for difficult to resect large, or metastatic tumors.
Lewis VO IL-11Rα: a novel target for the treatment of osteosarcoma. Adv Exp Med Biol. 2014; 804:285-9 [PubMed] Related Publications
Recent advances have shown that cell surface receptors are expressed differentially in normal and pathological conditions. Novel organ specific and disease specific proteins expressed on tumor vasculature have been identified by in vivo phage display technology and the diversity of the tumor-associated vasculature has provided the basis for the development of targeted therapeutics. Investigators recently screened a phage display library in a human cancer patient. An IL-11 mimic phage displaying the cyclic peptide CGRRAGGSC (single letter amino acid code) specifically bound to immobilized IL-11Rα. It has been demonstrated that the expression of the IL-11Rα is increased in several other types of tumors including osteosarcoma. The ability to selectively target the IL-11Rα may provide an alternative treatment of for a disease where new treatment options are truly needed.
Hingorani P, Sampson V, Lettieri C, Kolb EA Oncolytic viruses for potential osteosarcoma therapy. Adv Exp Med Biol. 2014; 804:259-83 [PubMed] Related Publications
Since the first anecdotal reports of dramatic tumor responses following a viral infection in early 1900s, the field of oncolytic virotherapy has evolved at a rapid pace finally making its way into clinical trials. A large number of both wild-type and genetically altered viruses with a preferential replication-competency for tumor cells have been studied in tissue cultures, animal models and in humans, with an ever increasing repertoire of new viruses being added to this pool. Although oncolytic viruses have caused dramatic antitumor responses in cell cultures and mouse models, their clinical effects in humans have been modest. Therefore, the current research is focused on understanding the mechanisms by which viruses kill tumor cells, the barriers to successful viral delivery and penetration into tumor cells, the role of the immune system in viral oncolysis and generating stronger target specific and replication competent viruses. Osteosarcoma is a challenging malignancy to identify novel targets for therapy due to its complex genetic make-up. Oncolytic virotherapy may be a promising approach as a novel therapeutic, not dependent on consistent expression of a single target. In this review we summarize the supportive evidence and rationale for use of viral oncolysis in osteosarcoma along with the specific challenges it may face.
Rodriguez CO Using canine osteosarcoma as a model to assess efficacy of novel therapies: can old dogs teach us new tricks? Adv Exp Med Biol. 2014; 804:237-56 [PubMed] Related Publications
Since its domestication more than 10,000 years ago, the dog has been the animal that most intimately shares our work and homelife. Interestingly, the dog also shares many of our diseases including cancer such as osteosarcoma. Like the human, osteosarcoma is the most common bone malignancy of the dog and death from pulmonary metastasis is the most common outcome. The incidence of this spontaneous bone neoplasm occurs ten times more frequently that it does so in children with about 8,000-10,000 cases estimated to occur in dogs in the USA. Because there is no "standard of care" in veterinary medicine, the dog can also serve us by being a model for this disease in children. Although the most common therapy for the dog with osteosarcoma is amputation followed by chemotherapy, not all owners choose this route. Consequently, novel therapeutic interventions can be attempted in the dog with or without chemotherapy that could not be done in humans with osteosarcoma due to ethical concerns. This chapter will focus on the novel therapies in the dog that have been reported or are in veterinary clinical trials at the author's institution. It is hoped that collaboration between veterinary oncologists and pediatric oncologists will lead to the development of novel therapies for (micro- or macro-) metastatic osteosarcoma that improve survival and might ultimately lead to a cure in both species.
Mohseny AB, Hogendoorn PC Zebrafish as a model for human osteosarcoma. Adv Exp Med Biol. 2014; 804:221-36 [PubMed] Related Publications
For various reasons involving biological comparativeness, expansive technological possibilities, accelerated experimental speed, and competitive costs, zebrafish has become a comprehensive model for cancer research. Hence, zebrafish embryos and full-grown fish have been instrumental for studies of leukemia, melanoma, pancreatic cancer, bone tumors, and other malignancies. Although because of its similarities to human osteogenesis zebrafish appears to be an appealing model to investigate osteosarcoma, only a few osteosarcoma specific studies have been accomplished yet. Here, we review interesting related and unrelated reports of which the findings might be extrapolated to osteosarcoma. More importantly, rational but yet unexplored applications of zebrafish are debated to expand the window of opportunities for future establishment of osteosarcoma models. Accordingly technological advances of zebrafish based cancer research, such as robotic high-throughput multicolor injection systems and advanced imaging methods are discussed. Furthermore, various use of zebrafish embryos for screening drug regimens by combinations of chemotherapy, novel drug deliverers, and immune system modulators are suggested. Concerning the etiology, the high degree of genetic similarity between zebrafish and human cancers indicates that affected regions are evolutionarily conserved. Therefore, zebrafish as a swift model system that allows for the investigation of multiple candidate gene-defects is presented.
Huang G, Nishimoto K, Yang Y, Kleinerman ES Participation of the Fas/FasL signaling pathway and the lung microenvironment in the development of osteosarcoma lung metastases. Adv Exp Med Biol. 2014; 804:203-17 [PubMed] Related Publications
The lungs are the most common site for the metastatic spread of osteosarcoma. Success in using chemotherapy to improve overall survival has reached a plateau. Understanding the biologic properties that permit osteosarcoma cells to grow in the lungs may allow the identification of novel therapeutic approaches-the goal being to alter the tumor cells' expression of cell surface proteins so that there is no longer compatibility with the metastatic niche. We have demonstrated that the Fas Ligand positive (FasL(+)) lung microenvironment eliminates Fas(+) osteosarcoma cells that metastasize to the lungs. Indeed, osteosarcoma lung metastases from patients are Fas(-), similar to what we found in several different mouse models. The Fas(+) cells are cleared from the lungs through apoptosis induced by the Fas signaling pathway following interaction of Fas on the tumor cell surface with the lung FasL. Blocking the Fas signaling pathway interferes with this process, allowing the Fas(+) cells to grow in the lungs. Our investigations show that Fas expression in osteosarcoma cells is regulated epigenetically by the micro-RNA miR-20a, encoded by the miR-17-92 cluster. Our studies support the feasibility of finding agents that can re-induce Fas expression as a novel therapeutic approach to treat osteosarcoma patients with lung metastases. We have identified two such agents, the histone deacetylase inhibitor entinostat and the chemotherapeutic agent gemcitabine (GCB). Aerosol GCB and oral entinostat induce the upregulation of Fas and the regression of established osteosarcoma lung metastases. Aerosol GCB was not effective in the FasL-deficient gld mouse confirming that the lung microenvironment was central to the success of this therapy. Our studies establish the critical role of the lung microenvironment in the metastatic process of osteosarcoma to the lungs and suggest an alternative focus for therapy, that is, incorporating the lung microenvironment as part of the treatment strategy against established osteosarcoma disease in the lungs.
The cause of death for the vast majority of cancer patients is the development of metastases at sites distant from that of the primary tumor. For most pediatric sarcoma patients such as those with osteosarcoma (OS), despite successful management of the primary tumor through multimodality approaches, the development of metastases, commonly to the lungs, is the cause of death. Significant improvements in long-term outcome for these patients have not been seen in more than 30 years. Furthermore, the long-term outcome for patients who present with metastatic disease is grave [1-5]. New treatment options are needed.Opportunities to improve outcomes for patients who present with metastases and those at-risk for progression and metastasis require an improved understanding of cancer progression and metastasis. With this goal in mind we and others have identified ezrin as a metastasis-associated protein that associated with OS and other cancers. Ezrin is the prototypical ERM (Ezrin/Radixin/Moesin) protein family member. ERMs function as linker proteins connecting the actin cytoskeleton and the plasma membrane. Since our initial identification of ezrin in pediatric sarcoma, an increasing understanding the role of ezrin in metastasis has emerged. Briefly, ezrin appears to allow metastatic cells to overcome a number of stresses experienced during the metastatic cascade, most notably the stress experienced as cells interact with the microenvironment of the secondary site. Cells must rapidly adapt to this environment in order to survive. Evidence now suggests a connection between ezrin expression and a variety of mechanisms linked to this important cellular adaptation including the ability of metastatic cells to initiate the translation of new proteins and to allow the efficient generation of ATP through a variety of sources. This understanding of the role of ezrin in the biology of metastasis is now sufficient to consider ezrin as an important therapeutic target in osteosarcoma patients. This chapter reviews our understanding of ezrin and the related ERM proteins in normal tissues and physiology, summarizes the expression of ezrin in human cancers and associations with clinical parameters of disease progression, reviews reports that detail a biological understanding of ezrin's role in metastatic progression, and concludes with a rationale that may be considered to target ezrin and ezrin biology in osteosarcoma.
The major goals of translational research in osteosarcoma entail the identification of prognostic factors and therapeutic targets. Given the relevance of epidermal growth factor receptor pathway to breast cancer and the finding that HER-2 was expressed in a proportion of osteosarcoma, it was reasonable to investigate this pathway further. Investigations of HER-2 in osteosarcoma have led to the publication of numerous conflicting reports with regard to the level and prognostic value of HER-2 expression, which are reviewed and discussed. Numerous lessons provided by this research experience are described. This pathway has also been explored as a therapeutic target with at least one study of trastuzumab for the treatment of osteosarcoma completed. Other studies utilizing alternative approaches to target the HER-2 receptor for the treatment of osteosarcoma have been considered.
Osteosarcoma (OS) metastatic disease is resistant to conventional chemotherapy. Tumor resistance to chemotherapy has been one of the major areas of concern to clinicians and the topic of many laboratory investigators. Evaluation of mechanisms implicated in OS lung metastasis resistance to chemotherapy has been the focus of some of our most recent work. We have previously demonstrated the therapeutic efficacy of aerosol gemcitabine (GCB) in OS lung metastases. However, a subset of cells fails to respond to GCB treatment and persists as isolated lung metastases in vivo. Autophagy, a physiological mechanism that supports nutritional deprivation under stressful conditions, has been implicated in tumor resistance to chemotherapy. We demonstrated the induction of autophagy by GCB in LM7 metastatic human OS cells and K7M3 metastatic murine OS cells. Inhibition of autophagy resulted in increased sensitivity to GCB in LM7 cells. By contrast, inhibiting autophagy in K7M3 cells decreased GCB sensitivity. Defining the role autophagy plays in chemotherapy response in different tumor types has become of greater importance in order to identify the best suitable therapeutic approach. In this chapter, we summarize some of the most recent work related to autophagy in OS, identify some of the known mechanisms, and address the different roles autophagy plays in chemotherapy response.
The RECQ family of DNA helicases is a conserved group of enzymes that are important for maintaining genomic integrity. In humans, there are five RECQ helicase genes, and mutations in three of them-BLM, WRN, and RECQL4-are associated with the genetic disorders Bloom syndrome, Werner syndrome, and Rothmund-Thomson syndrome (RTS), respectively. Importantly all three diseases are cancer predisposition syndromes. Patients with RTS are highly and uniquely susceptible to developing osteosarcoma; thus, RTS provides a good model to study the pathogenesis of osteosarcoma. The "tumor suppressor" role of RECQL4 and the other RECQ helicases is an area of active investigation. This chapter reviews what is currently known about the cellular functions of RECQL4 and how these may relate to tumorigenesis, as well as ongoing efforts to understand RECQL4's functions in vivo using animal models. Understanding the RECQ pathways may provide insight into avenues for novel cancer therapies in the future.
Mortus JR, Zhang Y, Hughes DP Developmental pathways hijacked by osteosarcoma. Adv Exp Med Biol. 2014; 804:93-118 [PubMed] Related Publications
Cancer of any type often can be described by an arrest, alteration or disruption in the normal development of a tissue or organ, and understanding of the normal counterpart's development can aid in understanding the malignant state. This is certainly true for osteosarcoma and the normal developmental pathways that guide osteoblast development that are changed in the genesis of osteogenic sarcoma. A carefully regulated crescendo-decrescendo expression of RUNX2 accompanies the transition from mesenchymal stem cell to immature osteoblast to mature osteoblast. This pivotal role is controlled by several pathways, including bone morphogenic protein (BMP), Wnt/β-catenin, fibroblast growth factor (FGF), and protein kinase C (PKC). The HIPPO pathway and its downstream target YAP help to regulate proliferation of immature osteoblasts and their maturation into non-proliferating mature osteoblasts. This pathway also helps regulate expression of the mature osteoblast protein osteocalcin. YAP also regulates expression of MT1-MMP, a membrane-bound matrix metalloprotease responsible for remodeling the extracellular matrix surrounding the osteoblasts. YAP, in turn, can be regulated by the ERBB family protein Her-4. Osteosarcoma may be thought of as a cell held at the immature osteoblast stage, retaining some of the characteristics of that developmental stage. Disruptions of several of these pathways have been described in osteosarcoma, including BMP, Wnt/b-catenin, RUNX2, HIPPO/YAP, and Her-4. Further, PKC can be activated by several receptor tyrosine kinases implicated in osteosarcoma, including the ERBB family (EGFR, Her-2 and Her-4 in osteosarcoma), IGF1R, FGF, and others. Understanding these functions may aid in the understanding the mechanisms underpinning clinical observations in osteosarcoma, including both the lytic and blastic phenotypes of tumors, the invasiveness of the disease, and the tendency for treated tumors to ossify rather than shrink. Through a better understanding of the relationship between normal osteoblast development and osteosarcoma, we may gain insights into novel therapeutic avenues and improved outcomes.
McManus MM, Weiss KR, Hughes DP Understanding the role of Notch in osteosarcoma. Adv Exp Med Biol. 2014; 804:67-92 [PubMed] Related Publications
The Notch pathway has been described as an oncogene in osteosarcoma, but the myriad functions of all the members of this complex signaling pathway, both in malignant cells and nonmalignant components of tumors, make it more difficult to define Notch as simply an oncogene or a tumor suppressor. The cell-autonomous behaviors caused by Notch pathway manipulation may vary between cell lines but can include changes in proliferation, migration, invasiveness, oxidative stress resistance, and expression of markers associated with stemness or tumor-initiating cells. Beyond these roles, Notch signaling also plays a vital role in regulating tumor angiogenesis and vasculogenesis, which are vital aspects of osteosarcoma growth and behavior in vivo. Further, osteosarcoma cells themselves express relatively low levels of Notch ligand, making it likely that nonmalignant cells, especially endothelial cells and pericytes, are the major source of Notch activation in osteosarcoma tumors in vivo and in patients. As a result, Notch pathway expression is not expected to be uniform across a tumor but likely to be highest in those areas immediately adjacent to blood vessels. Therapeutic targeting of the Notch pathway is likewise expected to be complicated. Most pharmacologic approaches thus far have focused on inhibition of gamma secretase, a protease of the presenilin complex. This enzyme, however, has numerous other target proteins that would be expected to affect osteosarcoma behavior, including CD44, the WNT/β-catenin pathway, and Her-4. In addition, Notch plays a vital role in tissue and organ homeostasis in numerous systems, and toxicities, especially GI intolerance, have limited the effectiveness of gamma secretase inhibitors. New approaches are in development, and the downstream targets of Notch pathway signaling also may turn out to be good targets for therapy. In summary, a full understanding of the complex functions of Notch in osteosarcoma is only now unfolding, and this deeper knowledge will help position the field to better utilize novel therapies as they are developed.
Rettew AN, Getty PJ, Greenfield EM Receptor tyrosine kinases in osteosarcoma: not just the usual suspects. Adv Exp Med Biol. 2014; 804:47-66 [PubMed] Related Publications
Despite aggressive surgical and chemotherapy protocols, survival rates for osteosarcoma patients have not improved over the last 30 years. Therefore, novel therapeutic agents are needed. Receptor tyrosine kinases have emerged as targets for the development of new cancer therapies since their activation leads to enhanced proliferation, survival, and metastasis. In fact, aberrant expression and activation of RTKs have been associated with the progression of many cancers. Studies from our lab using phosphoproteomic screening identified RTKs that are activated and thus may contribute to the signaling within metastatic human osteosarcoma cells. Functional genomic screening using siRNA was performed to distinguish which of the activated RTKs contribute to in vitro phenotypes associated with metastatic potential (motility, invasion, colony formation, and cell growth). The resulting RTK hits were then validated using independent validation experiments. From these results, we identified four RTKs (Axl, EphB2, FGFR2, and Ret) that have not been previously studied in osteosarcoma and provide targets for the development of novel therapeutics.
Osteosarcoma (OS) is the most common primary bone malignancy diagnosed in children and adolescents with a high propensity for local invasion and distant metastasis. Despite current multidisciplinary treatments, there has not been a drastic change in overall prognosis within the last two decades. With current treatments, 60-70 % of patients with localized disease survive. Given a propensity of Wnt signaling to control multiple cellular processes, including proliferation, cell fate determination, and differentiation, it is a critical pathway in OS disease progression. At the same time, this pathway is extremely complex with vast arrays of cross-talk. Even though decades of research have linked the role of Wnt to tumorigenesis, there are still outstanding areas that remain poorly understood and even controversial. The canonical Wnt pathway functions to regulate the levels of the transcriptional co-activator β-catenin, which ultimately controls key developmental gene expressions. Given the central role of this mediator, inhibition of Wnt/β-catenin signaling has been investigated as a potential strategy for cancer control. In OS, several secreted protein families modulate the Wnt/β-catenin signaling, including secreted Frizzled-related proteins (sFRPs), Wnt inhibitory protein (WIF), Dickkopf proteins (DKK-1,2,3), sclerostin, and small molecules. This chapter focuses on our current understanding of Wnt/β-catenin signaling in OS, based on recent in vitro and in vivo data. Wnt activates noncanonical signaling pathways as well that are independent of β-catenin which will be discussed. In addition, stem cells and their association with Wnt/β-catenin are important factors to consider. Ultimately, the multiple canonical and noncanonical Wnt/β-catenin agonists and antagonists need to be further explored for potential targeted therapies.
Jaffe N Historical perspective on the introduction and use of chemotherapy for the treatment of osteosarcoma. Adv Exp Med Biol. 2014; 804:1-30 [PubMed] Related Publications
Chemotherapy for treatment of osteosarcoma was demonstrated to be effective in eradicating primary tumor and pulmonary metastases in the mid-twentieth century. The first agents that held promise were doxorubicin and high-dose methotrexate with leucovorin (citrovorin factor) in the mid-1970s. Since then, other agents that can eliminate or cause regression of tumor have been discovered: cis-diamminedichloroplatinum II (cisplatin) and the oxazaphosphorines ifosfamide and cyclophosphamide. Additional agents await further study to define their potential. The effective agents have been utilized in various combination regimens and have escalated the survival rate from <10 to 75 %. They have also enabled pulmonary metastectomy in patients with persistent and/or recurrent pulmonary metastases and tumor ablation and limb salvage in 80 % of newly diagnosed patients. Unfortunately, however, despite these impressive advances no change in survival expectancy of patients with osteosarcoma during the past 40 years has occurred. There have been no new chemotherapeutic agents effective in addressing disease that is resistant to current agents; the few that have been introduced await further study to substantiate their efficacy. This also includes attempts at alternate administration of chemotherapy (intra-arterial and inhalation therapy.) In this chapter, we provide an account of the sequential introduction of the chemotherapeutic agents, review the results of their application in selected regimens, and discuss the role of neoadjuvant chemotherapy.
Chen K, Zhu C, Cai M, et al. Integrative metabolome and transcriptome profiling reveals discordant glycolysis process between osteosarcoma and normal osteoblastic cells. J Cancer Res Clin Oncol. 2014; 140(10):1715-21 [PubMed] Related Publications
BACKGROUND: Osteosarcoma (OS) is the most common primary malignant tumor of bone in children and adolescents. However, few biomarkers of diagnostic significance have been established. In recent years, high-throughput transcriptomic and metabolomic approaches make it possible for studying the levels of thousands of biomarkers simultaneously. METHODS: In this study, we integrated two disparate transcriptomic and metabolomic datasets to find meaningful biomarkers and then used an independent dataset to test the sensibility and specificity of these biomarkers. RESULTS: By using integrated two datasets, we discovered that the biomarkers involved in the glycolysis pathway are highly enriched, including 4 genes (ENO1, TPI1, PKG1 and LDHC) and 2 metabolites (lactate and pyruvate). The 4 genes were significantly down-regulated in OS samples as well as the 2 metabolites. The mixed metabolites + genes signature also outperformed metabolites or genes alone, with recall being 0.813 and F-measure being 0.812. And the AUC value of metabolites + genes classifier was 0.825 (compared to 0.58 for metabolites and 0.821 for genes alone). CONCLUSION: Our findings establish that integrated transcriptomic and metabolomic signature can be used to distinguish OS malignant with good diagnostic accuracy superior to other methods.
Osteosarcoma (OS) is the most common primary bone cancer exhibiting high genomic instability. This genomic instability affects multiple genes and microRNAs to a varying extent depending on patient and tumor subtype. Massive research is ongoing to identify genes including their gene products and microRNAs that correlate with disease progression and might be used as biomarkers for OS. However, the genomic complexity hampers the identification of reliable biomarkers. Up to now, clinico-pathological factors are the key determinants to guide prognosis and therapeutic treatments. Each day, new studies about OS are published and complicate the acquisition of information to support biomarker discovery and therapeutic improvements. Thus, it is necessary to provide a structured and annotated view on the current OS knowledge that is quick and easily accessible to researchers of the field. Therefore, we developed a publicly available database and Web interface that serves as resource for OS-associated genes and microRNAs. Genes and microRNAs were collected using an automated dictionary-based gene recognition procedure followed by manual review and annotation by experts of the field. In total, 911 genes and 81 microRNAs related to 1331 PubMed abstracts were collected (last update: 29 October 2013). Users can evaluate genes and microRNAs according to their potential prognostic and therapeutic impact, the experimental procedures, the sample types, the biological contexts and microRNA target gene interactions. Additionally, a pathway enrichment analysis of the collected genes highlights different aspects of OS progression. OS requires pathways commonly deregulated in cancer but also features OS-specific alterations like deregulated osteoclast differentiation. To our knowledge, this is the first effort of an OS database containing manual reviewed and annotated up-to-date OS knowledge. It might be a useful resource especially for the bone tumor research community, as specific information about genes or microRNAs is quick and easily accessible. Hence, this platform can support the ongoing OS research and biomarker discovery. Database URL: http://osteosarcoma-db.uni-muenster.de.
Lee AF, Pawel BR, Sullivan LM Significant immunohistochemical expression of human chorionic gonadotropin in high-grade osteosarcoma is rare, but may be associated with clinically elevated serum levels. Pediatr Dev Pathol. 2014 Jul-Aug; 17(4):278-85 [PubMed] Related Publications
Survival rates have plateaued at 70% for osteosarcoma. Proteins ectopically produced by malignant tumors may provide insight into new therapeutic targets. Osteosarcomas secreting human chorionic gonadotropin (hCG) have been suggested to have a worse prognosis. We examined the frequency of expression of β-subunit of hCG (β-hCG) in pretreatment osteosarcoma biopsies, and asked if it was associated with various clinical prognostic parameters, and the development of metastases. We subjected 51 pretreatment biopsies of high-grade osteosarcoma, from 51 patients, to β-hCG immunohistochemistry. In 19 of these patients, postchemotherapy metastatic biopsies also were examined for β-hCG expression. Clinical information (patient age, sex, survival status, and serum hCG in females only), and tumor characteristics (site, size, and presence of metastases) were recorded. The β-hCG positive and negative biopsies were separated and compared. Of 49 interpretable pretreatment biopsies, 28 (57%) showed positive cytoplasmic β-hCG expression: 27 with sparse positivity (1% of tumor cells) and 1 with frequent positivity (10% of tumor cells). The patient with frequent β-hCG positivity in her pretreatment biopsy had elevated serum hCG (88.2 mIU/mL) at diagnosis, decreasing to undetectable following chemotherapy and definitive resection. There was no difference in clinical parameters or rate of metastasis between β-hCG positive versus negative groups. Expression of β-hCG may be seen in high-grade osteosarcoma, but frequent β-hCG immunohistochemical expression by tumor cells, associated with clinically elevated serum β-hCG, is rare. Recognition that some nongerm cell tumors may produce β-hCG can prevent confusion with malignancies containing neoplastic syncytiotrophoblast cells, including germ cell and trophoblastic tumors.
Yang X, Yang P, Shen J, et al. Prevention of multidrug resistance (MDR) in osteosarcoma by NSC23925. Br J Cancer. 2014; 110(12):2896-904 [PubMed] Article available free on PMC after 10/06/2015 Related Publications
BACKGROUND: The major limitation to the success of chemotherapy in osteosarcoma is the development of multidrug resistance (MDR). Preventing the emergence of MDR during chemotherapy treatment has been a high priority of clinical and investigational oncology, but it remains an elusive goal. The NSC23925 has recently been identified as a novel and potent MDR reversal agent. However, whether NSC23925 can prevent the development of MDR in cancer is unknown. Therefore, this study aims to evaluate the effects of NSC23925 on prevention of the development of MDR in osteosarcoma. METHODS: Human osteosarcoma cell lines U-2OS and Saos were exposed to increasing concentrations of paclitaxel alone or in combination with NSC23925 for 6 months. Cell sublines selected at different time points were evaluated for their drug sensitivity, drug transporter P-glycoprotein (Pgp) expression and activity. RESULTS: We observed that tumour cells selected with increasing concentrations of paclitaxel alone developed MDR with resistance to paclitaxel and other Pgp substrates, whereas cells cultured with paclitaxel-NSC23925 did not develop MDR and cells remained sensitive to chemotherapeutic agents. Paclitaxel-resistant cells showed high expression and activity of the Pgp, whereas paclitaxel-NSC23925-treated cells did not express Pgp. No changes in IC50 and Pgp expression and activity were observed in cells grown with the NSC23925 alone. CONCLUSIONS: Our findings suggest that NSC23925 may prevent the development of MDR by specifically preventing the overexpression of Pgp. Given the significant incidence of MDR in osteosarcoma and the lack of effective agents for prevention of MDR, NSC23925 and derivatives hold the potential to improve the outcome of cancer patients with poor prognosis due to drug resistance.
Shirazian S, Agha-Hosseini F Oral osteosarcoma: a case report and analysis of previously reported cases. N Y State Dent J. 2014; 80(2):50-4 [PubMed] Related Publications
Osteosarcoma is the most common malignancy of mesenchymal cells after hematopoietic neoplasms. Most originate within bones, but the occurrence of this malignancy in the jaw bones is rare. There is controversy about the characteristics of this tumor in the literature. The aim of this paper was to collect the previous reported data and provide a statistical analysis of them. Additionally, we have reported a case of mandibular osteosarcoma.
Hong JB, Cho KH, Choi JH Periosteal osteosarcoma arising from the rib and scapula: imaging features in two cases. Korean J Radiol. 2014; 15(3):370-5 [PubMed] Article available free on PMC after 10/06/2015 Related Publications
Periosteal osteosarcoma is an extremely rare chondroblastic osteosarcoma in the flat bone. There were authors reporting of two cases of periosteal osteosarcoma in the highly unusual sites. One of them arose from the rib, in a 17-year-old male, which appeared as a hypodense juxtacortical mass with periosteal reaction on CT. The other one arose from the scapula, in a 17-year-old female, which showed the intermediate signal intensity (SI) on T1-weighted image (WI), heterogeneous high SI on T2WI, and rim-enhancement on contrast-enhanced T1WI with cortical destruction on MRI.