Targeting EZH2-mediated methylation of H3K27 inhibits proliferation and migration of Synovial Sarcoma in vitro.

Synovial sarcoma is an aggressive soft tissue sarcoma genetically defined by the fusion oncogene SS18-SSX. It is hypothesized that either SS18-SSX disrupts SWI/SNF complex inhibition of the polycomb complex 2 (PRC2) methyltransferase Enhancer of Zeste Homologue 2 (EZH2), or that SS18-SSX is able to directly recruit PRC2 to aberrantly silence target genes. This is of potential therapeutic value as several EZH2 small molecule inhibitors are entering early phase clinical trials. In this study, we first confirmed EZH2 expression in the 76% of human synovial sarcoma samples. We subsequently investigated EZH2 as a therapeutic target in synovial sarcoma in vitro. Knockdown of EZH2 by shRNA or siRNA resulted in inhibition of cell growth and migration across a series of synovial sarcoma cell lines. The EZH2 selective small-molecule inhibitor EPZ005687 similarly suppressed cell proliferation and migration. These data support the hypothesis that targeting EZH2 may be a promising therapeutic strategy in the treatment of synovial sarcoma; clinical trials are initiating enrollment currently

Anti-proliferative but not anti-angiogenic tyrosine kinase inhibitors enrich for cancer stem cells in soft tissue sarcoma.

BackgroundIncreasing studies implicate cancer stem cells (CSCs) as the source of resistance and relapse following conventional cytotoxic therapies. Few studies have examined the response of CSCs to targeted therapies, such as tyrosine kinase inhibitors (TKIs). We hypothesized that TKIs would have differential effects on CSC populations depending on their mechanism of action (anti-proliferative vs. anti-angiogenic).MethodsWe exposed human sarcoma cell lines to sorafenib, regorafenib, and pazopanib and assessed cell viability and expression of CSC markers (ALDH, CD24, CD44, and CD133). We evaluated survival and CSC phenotype in mice harboring sarcoma metastases after TKI therapy. We exposed dissociated primary sarcoma tumors to sorafenib, regorafenib, and pazopanib, and we used tissue microarray (TMA) and primary sarcoma samples to evaluate the frequency and intensity of CSC markers after neoadjuvant therapy with sorafenib and pazopanib. Parametric and non-parametric statistical analyses were performed as appropriate.ResultsAfter functionally validating the CSC phenotype of ALDHbright sarcoma cells, we observed that sorafenib and regorafenib were cytotoxic to sarcoma cell lines (P < 0.05), with a corresponding 1.4 - 2.8 fold increase in ALDHbright cells from baseline (P < 0.05). In contrast, we observed negligible effects on viability and CSC sub-populations with pazopanib. At low doses, there was progressive CSC enrichment in vitro after longer term exposure to sorafenib although the anti-proliferative effects were attenuated. In vivo, sorafenib improved median survival by 11 days (P < 0.05), but enriched ALDHbright cells 2.5 - 2.8 fold (P < 0.05). Analysis of primary human sarcoma samples revealed direct cytotoxicity following exposure to sorafenib and regorafenib with a corresponding increase in ALDHbright cells (P < 0.05). Again, negligible effects from pazopanib were observed. TMA analysis of archived specimens from sarcoma patients treated with sorafenib demonstrated significant enrichment for ALDHbright cells in the post-treatment resection specimen (P < 0.05), whereas clinical specimens obtained longitudinally from a patient treated with pazopanib showed no enrichment for ALDHbright cells (P > 0.05).ConclusionsAnti-proliferative TKIs appear to enrich for sarcoma CSCs while anti-angiogenic TKIs do not. The rational selection of targeted therapies for sarcoma patients may benefit from an awareness of the differential impact of TKIs on CSC populations

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

Evaluation of Overall Survival (OS) and Event-Free Survival (EFS) of paediatric sarcoma patients at a single institution

Aims: To evaluate OS and EFS of paediatric sarcoma patients with an interest in comparing metastatic cases with non-metastatic cases, and compiling statistics on treatment methods. Methods: Information was obtained from patient notes in the Schiehallion ward. These contained information about diagnosis, treatment, prognostic indicators, and outcomes for each patient. Results: 56 patients, 2001-2008. Osteosarcoma: 11 patients, 7♂, 4♀; age range: 4-16; = 10; OS = 64%, EFS = 55%; Primary site of disease: Femur (47%), Tibia (41%), Humerus (5.5%), Scapula (5.5%), Other (1%); Metastatic Rate = 27% (OS = 0%). Ewing’s sarcoma: 24 patients, 10♂, 14♀; age range: 1-16, = 12; OS = 71%, EFS = 58%; Primary site of disease: Pelvis (29%), Femur (22%), Paraspinal (16%), Chest Wall (10%), Tibia (10%), Other (13%); Metastatic Rate = 21% (OS = 40%; EFS = 40%); Alveolar rhabdomyosarcoma: 10 patients; OS= 80%, EFS = 60%; Metastatic Rate = 20% (OS = 100%; EFS = 100%). Embryonal rhabdomyosarcoma: 11 patients; OS = 73%, EFS = 73%; Metastatic Rate = 0%. Conclusions: Our results reflect access to an experienced and innovative paediatric sarcoma service with close links to a national Sarcoma MDT. The data falls in line with other studies in terms of age of onset, location of primary tumour, metastatic rate, site of metastases, and prognosis for all cancer types. Limb salvage surgery is greatly favoured over amputation for both osteosarcoma and Ewing’s sarcoma. Females have a more favourable prognosis in osteosarcoma and a slightly poorer prognosis in Ewing’s sarcoma. Yorkhill’s overall survival rates are currently better than the UK-wide statistic for three of the four tumours examined.</p

Biphenotypic Sinonasal Sarcoma-Case Report and Review of Clinicopathological Features and Diagnostic Modalities.

Background Biphenotypic sinonasal sarcoma is a recently described malignancy showing dual differentiation with both myogenic and neural elements. Due to its histologic similarities to other sinonasal malignancies, it is a diagnostic challenge. Objective The main purpose of this article is to report a case of biphenotypic sinonasal sarcoma and to consolidate data and provide a comprehensive review regarding pathological differences between biphenotypic sarcoma and other sinonasal malignancies and diagnostic modalities used for biphenotypic sarcoma. Material and Methods A systematic review of all cases of biphenotypic sinonasal sarcoma was performed using electronic databases (PubMed and Medline). Data collected included age, gender, symptoms, sub-site of origin, immunophenotyping, metastasis, recurrence, treatment, duration of follow-up, and survival outcomes. Results Ninety-five cases of biphenotypic sarcoma were found with mean age at diagnosis of 52.36 years (range, 24-87 years). Female to male ratio was 2.27:1. Extra-sinonasal extension was present in 28%. Immunophenotyping revealed that S-100 and SMA (smooth muscle actin) were consistently positive, while SOX-10 was consistently negative. PAX3-MAML3 fusion [t (2; 4) (q35; q31.1)] was the most common genetic rearrangement. Surgical excision with or without adjuvant radiotherapy was the most frequent treatment modality used. Recurrence was observed in 32% of cases with follow-up. None of the cases reported metastasis. Three patients had died at the time of publication that included one case with intracranial extension. Conclusion Biphenotypic sarcoma is distinct sinonasal malignancy with unique clinicopathological features. Testing involving a battery of myogenic and neural immunomarkers is essential for diagnostic confirmation and is a clinically useful endeavor when clinical suspicion is high. © 2019 Georg Thieme Verlag KG Stuttgart. New York

Exploring the Importance of Single Nucleotide Polymorphisms of HSPA9 in DNA of Sarcoma Patients

The aim of this project was to identify genetic variants that may influence the risk and progression of sarcoma through targeted genotyping of HSPA9 gene. It is important to look at genetic variants in DNA samples because if a variant is determined to be more likely than another, a screening for the particular variant can be done to identify a patient’s risk of sarcoma. The study population was sarcoma patients from the International Sarcoma Kindred Study. These patients had no mutations in p53 or MDM2. Genotyping data from the HapMap project (hapmap.org) for HSPA9 was used to identify the polymorphisms needed to tag the entire region. In order to genotype the DNA sample, KASP reagents (KBioSciences, UK) were used. KASP uses a two-set PCR process. Allele specific primers are used to preferentially amplify each allele of a given SNP. The specific genetic variations of HSPA9 in sarcoma patient DNA samples with no mutations in p53 or MDM2 amplification are not more or less likely to occur than in DNA samples with the mutation or amplification. If continued research can show that MDM2 is not amplified, but activated through other mechanisms such as the interaction between polymorphisms of mitochondrial genes, p53, or MDM2, we can propose anti-MDM2 therapies to the patients with these polymorphisms

Associations of clock genes polymorphisms with soft tissue sarcoma susceptibility and prognosis

BACKGROUND: Dysfunction of the circadian clock and polymorphisms of some circadian genes have been linked to cancer development and progression. We investigated the relationship between circadian genes germline variation and susceptibility or prognosis of patients with soft tissue sarcoma. PATIENTS AND METHODS: We considered the 14 single nucleotide polymorphisms (SNPs) of 6 core circadian genes that have a minor allele frequency >\u20095% and that are known to be associated with cancer risk or prognosis. Genotyping was performed by q-PCR. Peripheral blood and clinic-pathological data were available for 162 patients with liposarcoma or leiomyosarcoma and 610 healthy donors. Associations between the selected clock genes polymorphisms and sarcoma susceptibility or prognosis were tested assuming 3 models of inheritance: additive, recessive and dominant. Subgroup analysis based on sarcoma histotype was performed under the additive genetic model. Multivariate logistic regression and multivariate Cox proportional hazard regression analyses were utilized to assess the association between SNPs with patient susceptibility and survival, respectively. Pathway variation analysis was conducted employing the Adaptive Rank Truncated Product method. RESULTS: Six out of the 14 analyzed SNPs were statistically significantly associated with susceptibility or prognosis of soft tissue sarcoma (P <\u20090.05). The present analysis suggested that carriers of the minor allele of the CLOCK polymorphism rs1801260 (C) or of PER2 rs934945 (T) had a reduced predisposition to sarcoma (26% and 35% respectively with the additive model) and liposarcoma (33% and 41% respectively). The minor allele (A) of NPAS2 rs895520 was associated with an increased predisposition to sarcoma of 33% and leiomyosarcoma of 44%. RORA rs339972 C allele was associated with a decreased predisposition to develop sarcoma assuming an additive model (29%) and leiomyosarcoma (36%). PER1 rs3027178 was associated with a reduced predisposition only in liposarcoma subgroup (32%). rs7602358 located upstream PER2 was significantly associated with liposarcoma survival (HR: 1.98; 95% CI 1.02-3.85; P\u2009=\u20090.04). Germline genetic variation in the circadian pathway was associated with the risk of developing soft tissue sarcoma (P\u2009=\u20090.035). CONCLUSIONS: Genetic variation of circadian genes appears to play a role in the determinism of patient susceptibility and prognosis. These findings prompt further studies to fully dissect the molecular mechanisms

Metastatic Ewing's sarcoma to the right ventricle

Ewing's sarcoma is a round cell neoplasm derived from neural crest cells that is part of the primitive neuroectodermal tumor (PNET) family. It is a rare, aggressive malignancy that affects young people, most commonly in the second decade of life. The treatment of localized disease has improved greatly over the past four decades, but the prognosis for metastatic disease remains poor. Cardiac metastases of Ewing's sarcoma are exceedingly rare, with only a few reported cases. This article presents a case of a 22 year old man with a history of Ewing's sarcoma of the bone involving the right kneepeer-reviewe