Increased risk for other cancers in individuals with Ewing sarcoma and their relatives.

BackgroundThere are few reports of the association of other cancers with Ewing sarcoma in patients and their relatives. We use a resource combining statewide genealogy and cancer reporting to provide unbiased risks.MethodsUsing a combined genealogy of 2.3 million Utah individuals and the Utah Cancer Registry (UCR), relative risks (RRs) for cancers of other sites were estimated in 143 Ewing sarcoma patients using a Cox proportional hazards model with matched controls; however, risks in relatives were estimated using internal cohort-specific cancer rates in first-, second-, and third-degree relatives.ResultsCancers of three sites (breast, brain, complex genotype/karyotype sarcoma) were observed in excess in Ewing sarcoma patients. No Ewing sarcoma patients were identified among first-, second-, or third-degree relatives of Ewing sarcoma patients. Significantly increased risk for brain, lung/bronchus, female genital, and prostate cancer was observed in first-degree relatives. Significantly increased risks were observed in second-degree relatives for breast cancer, nonmelanoma eye cancer, malignant peripheral nerve sheath cancer, non-Hodgkin lymphoma, and translocation sarcomas. Significantly increased risks for stomach cancer, prostate cancer, and acute lymphocytic leukemia were observed in third-degree relatives.ConclusionsThis analysis of risk for cancer among Ewing sarcoma patients and their relatives indicates evidence for some increased cancer predisposition in this population which can be used to individualize consideration of potential treatment of patients and screening of patients and relatives

Germline PTPRD mutations in Ewing sarcoma: biologic and clinical implications.

Ewing sarcoma occurs in children, adolescents and young adults. High STAT3 levels have been reported in approximately 50% of patients with Ewing sarcoma, and may be important in tumorigenesis. Protein tyrosine phosphatase delta (PTPRD) is a tumor suppressor that inhibits STAT3 activation. To date, while somatic mutations in PTPRD have been reported in diverse tumors, germline mutations of PTPRD have not been investigated in Ewing sarcoma or other cancers. We identified a novel germline mutation in the PTPRD gene in three of eight patients (37.5%) with metastatic Ewing sarcoma. Although the functional impact in two of the patients is unclear, in one of them the aberration was annotated as a W775stop germline mutation, and would be expected to lead to gene truncation and, hence, loss of the STAT3 dephosphorylation function of PTPRD. Since STAT3 is phosphorylated after being recruited to the insulin growth factor receptor (IGF-1R), suppression of IGF-1R could attenuate the enhanced STAT3 activation expected in the presence of PTPRD mutations. Of interest, two of three patients with germline PTPRD mutations achieved durable complete responses following treatment with IGF-1R monoclonal antibody-based therapies. Our pilot data suggest that PTPRD germline mutations may play a role in the development of Ewing sarcoma, a disease of young people, and their presence may have implications for therapy

C/EBPβ-1 promotes transformation and chemoresistance in Ewing sarcoma cells.

CEBPB copy number gain in Ewing sarcoma was previously shown to be associated with worse clinical outcome compared to tumors with normal CEBPB copy number, although the mechanism was not characterized. We employed gene knockdown and rescue assays to explore the consequences of altered CEBPB gene expression in Ewing sarcoma cell lines. Knockdown of EWS-FLI1 expression led to a decrease in expression of all three C/EBPβ isoforms while re-expression of EWS-FLI1 rescued C/EBPβ expression. Overexpression of C/EBPβ-1, the largest of the three C/EBPβ isoforms, led to a significant increase in colony formation when cells were grown in soft agar compared to empty vector transduced cells. In addition, depletion of C/EBPβ decreased colony formation, and re-expression of either C/EBPβ-1 or C/EBPβ-2 rescued the phenotype. We identified the cancer stem cell marker ALDH1A1 as a target of C/EBPβ in Ewing sarcoma. Furthermore, increased expression of C/EBPβ led to resistance to chemotherapeutic agents. In summary, we have identified CEBPB as an oncogene in Ewing sarcoma. Overexpression of C/EBPβ-1 increases transformation, upregulates expression of the cancer stem cell marker ALDH1A1, and leads to chemoresistance

The effect of Imp-2 on Ewing sarcoma cancer stem cells: when epigenetics orchestrate tumor growth

Ewing's sarcoma family tumors Ewing sarcoma is part of the Ewing's sarcoma family tumors (ESFTs) that includes peripheral primitive neuroectodermal tumor (PNET), extraosseous ewing sarcoma, Askin's tumor and atypical Ewing sarcoma. These tumors share histological and immunohistochemical similarities and display a single chromosomal translocation. ESFT is the second most frequent malignant bone tumor, after osteosarcoma, of adolescents and young adults. ESFTs are very aggressive and often relapse after treatment. Ewing sarcoma, on which this work will focus, occurs predominantly in the femur, the pelvis and less commonly in the upper extremities, axial skeleton, ribs and face with a peak incidence between 10 and 15 years of age. The histology of these tumors reflects poor differentiation and presents as small round cells with a halo of cytoplasm around the nucleus. They are therefore often referred to as small round blue cell tumors. Immunohistochemical analysis of ESFT reveals expression of the lymphoid cell adhesion receptor CD99, neural markers including NSE, S-100, synaptophysin and CD56 and mesenchymal markers including vimentin. Macroscopically, Ewing sarcoma is grey- white with zones of necrosis and fibrosis. It is associated with a survival rate of 65% at 5 years if treated with current multimodal therapy, which includes surgery, chemotherapy and radiation. However, Ewing sarcoma often displays multidrug resistance, which explains the frequent relapse. The underlying event in Ewing sarcoma pathogenesis is the non-random balanced chromosomal translocation between chromosome 11 and chromosome 22, t(11q23;22q12). It causes fusion between EWS gene on chromosome 22q12 and an ETS family gene on chromosome 11q24 (FLI gene in 85% of cases or ERG, ETV1, ETV2, FEV) (1). This translocation plays an essential role in the development and the maintenance of ESFT (2) and it is also used for diagnosis by FISH and RT-PCR. 4 The fusion gene formed encodes an aberrant transcription factor, which drives the expression or repression of genes implicated in regulation of cell proliferation and transformation by binding to their promoters and thus playing a crucial role in Ewing sarcoma pathogenesis

Immunostimulation by OX40 Ligand Transgenic Ewing Sarcoma Cells

Interleukin-2 (IL-2) transgenic Ewing sarcoma cells can induce tumor specific T and NK cell responses and reduce tumor growth in vivo and in vitro. Nevertheless, the efficiency of this stimulation is not high enough to inhibit tumor growth completely. In addition to recognition of the cognate antigen, optimal T cell stimulation requires signals from so-called co-stimulatory molecules. Several members of the tumor necrosis factor superfamily (TNFSF) have been identified as co-stimulatory molecules that can augment anti-tumor immune responses. OX40 (CD134) and OX40 ligand (OX40L = CD252; also known as tumor necrosis factor ligand family member 4) is one example for such receptor/ligand pair with co-stimulatory function. In the present investigation we generated OX40L transgenic Ewing sarcoma cells and tested their immuno-stimulatory activity in vitro. OX40L transgenic Ewing sarcoma cells showed preserved expression of Ewing sarcoma associated (anti)gens including lipase member I (LIPI), cyclin D1 (CCND1), cytochrome P450 family member 26B1 (CYP26B1) and the Ewing sarcoma breakpoint region 1-friend leukemia virus integration 1 (EWSR1-FLI1) oncogene. OX40L expressing tumor cells showed a trend for enhanced immune stimulation against Ewing sarcoma cells in combination with IL-2 and stimulation of CD137. Our data suggest that inclusion of the OX40/OX40L pathway of co-stimulation might improve immunotherapy strategies for treatment of Ewing sarcoma

Molecular dissection of the mechanism by which EWS/FLI expression compromises actin cytoskeletal integrity and cell adhesion in Ewing sarcoma.

Ewing sarcoma is the second-most-common bone cancer in children. Driven by an oncogenic chromosomal translocation that results in the expression of an aberrant transcription factor, EWS/FLI, the disease is typically aggressive and micrometastatic upon presentation. Silencing of EWS/FLI in patient-derived tumor cells results in the altered expression of hundreds to thousands of genes and is accompanied by dramatic morphological changes in cytoarchitecture and adhesion. Genes encoding focal adhesion, extracellular matrix, and actin regulatory proteins are dominant targets of EWS/FLI-mediated transcriptional repression. Reexpression of genes encoding just two of these proteins, zyxin and α5 integrin, is sufficient to restore cell adhesion and actin cytoskeletal integrity comparable to what is observed when the EWS/FLI oncogene expression is compromised. Using an orthotopic xenograft model, we show that EWS/FLI-induced repression of α5 integrin and zyxin expression promotes tumor progression by supporting anchorage-independent cell growth. This selective advantage is paired with a tradeoff in which metastatic lung colonization is compromised