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© The Author(s) 2021., BIRC3 is monoallelically deleted in up to 80% of chronic lymphocytic leukemia (CLL) cases harboring del(11q). In addition, truncating mutations in the remaining allele of this gene can lead to BIRC3 biallelic inactivation, which has been shown to be a marker for reduced survival in CLL. Nevertheless, the biological mechanisms by which these lesions could contribute to del(11q) CLL pathogenesis and progression are partially unexplored. We implemented the CRISPR/Cas9-editing system to generate isogenic CLL cell lines harboring del(11q) and/or BIRC3 mutations, modeling monoallelic and biallelic BIRC3 loss. Our results reveal that monoallelic BIRC3 deletion in del(11q) cells promotes non-canonical NF-κB signaling activation via RelB-p52 nuclear translocation, being these effects allelic dose-dependent and therefore further enhanced in del(11q) cells with biallelic BIRC3 loss. Moreover, we demonstrate ex vivo in primary cells that del(11q) cases including BIRC3 within their deleted region show evidence of non-canonical NF-κB activation which correlates with high BCL2 levels and enhanced sensitivity to venetoclax. Furthermore, our results show that BIRC3 mutations in del(11q) cells promote clonal advantage in vitro and accelerate leukemic progression in an in vivo xenograft model. Altogether, this work highlights the biological bases underlying disease progression of del(11q) CLL patients harboring BIRC3 deletion and mutation., This work was supported by grants from the Spanish Fondo de Investigaciones Sanitarias PI15/01471, PI18/01500, Instituto de Salud Carlos III (ISCIII), European Regional Development Fund (ERDF) “Una manera de hacer Europa”, “Consejería de Educación, Junta de Castilla y León” (SA271P18), “Proyectos de Investigación del SACYL”, Spain GRS 2062/A/19, GRS 1847/A/18, GRS1653/A17,“Fundación Memoria Don Samuel Solórzano Barruso” (FS/23-2018), by grants (RD12/0036/0069) from Red Temática de Investigación Cooperativa en Cáncer (RTICC), Universidad de Salamanca (Programa XIII), Centro de Investigación Biomédica en Red de Cáncer (CIBERONC CB16/12/00233) and SYNtherapy “Synthetic Lethality for Personalized Therapy-based Stratification In Acute Leukemia” (ERAPERMED2018-275); ISCIII (AC18/00093), co-funded by ERDF/ESF, “Investing in your future”. M.Q.Á. and A.E.R.V. are supported with a research grant by FEHH (“Fundación Española de Hematología y Hemoterapia”); M.H.S. holds a Sara Borrell postdoctoral contract (CD19/00222) from the Instituto de Salud Carlos III (ISCIII). C.P.C. was supported by an “Ayuda predoctoral en Oncología” (AECC) and is a recipient of a PFIS grant (FI19/00191) from Instituto de Salud Carlos III; PFIS grant and Sara Borrell postdoctoral contrat are co-founded by Fondo Social Europeo (FSE) “El Fondo Social Europeo invierte en tu futuro”; J.L.O. and R.B.S. are supported by a grant from the University of Salamanca (“Contrato postdoctoral programa II”).

This study evaluated the phenolic profile and the antioxidant capacity of strawberries (Fragaria x ananassa Duch., cv. Primoris) cultivated under reduction of nitrogen and adverse irrigation conditions (high salinity), such as those prevailing in Almeria (south-eastern Spain). The phenolic compound and anthocyanin profiles were analysed by HPLC-DAD-ESI/MSn, and the antioxidant activity. Nineteen phenolic compounds were quantified, mainly ellagitannins, anthocyanins, and flavan-3-ols. The total phenolic content ranged from 731 to 1521 mg/100 g of dried weight. The flavan-3-ols group compounds from the strawberries were positively affected by saline stress, especially the afz-(e)Catechin content in the first sampling. The reduction of nitrogen and the adverse irrigation conditions for the cultivation of strawberries (cv. Primoris) partially affected the phenolic composition, with the harvesting dates having a greater influence.

© 2021 The Authors., [Background]: Several genetic alterations have been identified as driver events in chronic lymphocytic leukemia (CLL) pathogenesis and oncogenic evolution. Concurrent driver alterations usually coexist within the same tumoral clone, but how the cooperation of multiple genomic abnormalities contributes to disease progression remains poorly understood. Specifically, the biological and clinical consequences of concurrent high-risk alterations such as del(11q)/ATM-mutations and del(17p)/TP53-mutations have not been established., [Methods]: We integrated next-generation sequencing (NGS) and clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 techniques to characterize the in vitro and in vivo effects of concurrent monoallelic or biallelic ATM and/or TP53 alterations in CLL prognosis, clonal evolution, and therapy response., [Results]: Targeted sequencing analysis of the co-occurrence of high-risk alterations in 271 CLLs revealed that biallelic inactivation of both ATM and TP53 was mutually exclusive, whereas monoallelic del(11q) and TP53 alterations significantly co-occurred in a subset of CLL patients with a highly adverse clinical outcome. We determined the biological effects of combined del(11q), ATM and/or TP53 mutations in CRISPR/Cas9-edited CLL cell lines. Our results showed that the combination of monoallelic del(11q) and TP53 mutations in CLL cells led to a clonal advantage in vitro and in in vivo clonal competition experiments, whereas CLL cells harboring biallelic ATM and TP53 loss failed to compete in in vivo xenotransplants. Furthermore, we demonstrated that CLL cell lines harboring del(11q) and TP53 mutations show only partial responses to B cell receptor signaling inhibitors, but may potentially benefit from ATR inhibition., [Conclusions]: Our work highlights that combined monoallelic del(11q) and TP53 alterations coordinately contribute to clonal advantage and shorter overall survival in CLL., Spanish Fondo de Investigaciones Sanitarias, Grant/Award Numbers: PI15/01471, PI18/01500); Fundación Memoria Don Samuel Solórzano Barruso, Grant/Award Number: RD12/0036/0069

Chronic myeloid leukemia (CML) is a hematopoietic malignancy produced by a unique oncogenic event involving the constitutively active tyrosine-kinase (TK) BCR/ABL1. TK inhibitors (TKI) changed its prognosis and natural history. Unfortunately, ABL1 remains unaffected by TKIs. Leukemic stem cells (LSCs) remain, and resistant mutations arise during treatment. To address this problem, we have designed a therapeutic CRISPR-Cas9 deletion system targeting BCR/ABL1. The system was efficiently electroporated to cell lines, LSCs from a CML murine model, and LSCs from CML patients at diagnosis, generating a specific ABL1 null mutation at high efficiency and allowing the edited leukemic cells to be detected and tracked. The CRISPR-Cas9 deletion system triggered cell proliferation arrest and apoptosis in murine and human CML cell lines. Patient and murine-derived xenografts with CRISPR-edited LSCs in NOD SCID gamma niches revealed that normal multipotency and repopulation ability of CRISPR edited LSCs were fully restored. Normal hematopoiesis was restored, avoiding myeloid bias. To the best of our knowledge, we show for the first time how a CRISPR-Cas9 deletion system efficiently interrupts BCR/ABL1 oncogene in primary LSCs to bestow a therapeutic benefit. This study is a proof of concept for genome editing in all those diseases, like CML, sustained by a single oncogenic event, opening up new therapeutic opportunities.

Chronic myeloid leukemia (CML) is a hematopoietic stem cell disease produced by a unique oncogenic event involving the constitutively active tyrosine kinase (TK) BCR/ABL1. TK activity explains most features of CML, such as tumor development and maintenance. TK-inhibitory (TKI) drugs have changed its prognosis and natural history. Unfortunately, the ABL1 gene persists unaffected by TKIs, leukemic stem cells (LSCs) remains, resistant mutations arise and adverse effects may occur during treatment. To address this problem, we have designed a potential therapeutic alternative with CRISPR/Cas9 genome editing nucleases that target LSCs. The strategy was successfully developed in murine and human cell lines and finally was evaluated in primary LSCs isolated from CML transgenic mice and from CML patients. Mouse CML-LSCs edited were orthotopic transplanted in immunodeficient NSG niches where restored the normal hematopoiesis. Importantly, patient-derived xenografts with CD34+-LSCs edited, repopulated and restored the normal hematopoiesis in immunodeficient NSG niches. We show, for the first time, how CRISPR technology efficiently interrupts the BCR/ABL1 oncogene in murine and human LSCs to provide a significant therapeutic benefit. We propose human CML as a potential candidate for CRISPR therapy, providing proof-of-principle for genome editing in CML patients, and open new avenues for the application of this technique in other fusion genes.Key pointsCRISPR system destroys BCR/ABL oncogene and induces a therapeutic benefit in a CML mouse model and CML patient derived xenografts.

Large-scale next-generation sequencing (NGS) studies have suggested common patterns of co-occurrence or mutual exclusivity between genetic alterations in chronic lymphocytic leukemia (CLL). However, little is known about how most of these alterations cooperate to drive CLL pathogenesis, as well as the impact of these concurrencies in clinical outcome. In this regard, we investigated the clinical and biological impact of the co-occurrence of high-risk lesions such as del(11q)/ATM mutation and del(17p)/TP53 mutation by integrating NGS and CRISPR/Cas9 approaches. To address these questions, we first analyzed the mutational profile of 271 CLLs (17.3% del(11q); 10.7% del(17p)). The most frequently mutated genes were NOTCH1 (20%), TP53 (14%), SF3B1 (11%) and ATM (10%). Within del(11q), 32% showed TP53 alterations (53% biallelic; 47% monoallelic). Interestingly, patients harboring combined del(11q) and TP53 alterations by either mutation or deletion (del(11q) TP53ALT) exhibited significantly shorter overall survival (OS) than del(11q) CLLs without TP53 alterations (del(11q) TP53WT) and those TP53 altered without del(11q) (no del(11q) TP53ALT) (median 17 vs. 88, 36 months; P=0.0004, P=0.02). Conversely, we observed a significant lack of ATM mutations in CLLs with biallelic TP53 alterations (P=0.002) and a mutual exclusivity between biallelic TP53 and biallelic ATM losses (P=0.03)(Fig 1A). Based on the NGS results, we next used the CRISPR/Cas9 system to model monoallelic and biallelic ATM and TP53 loss in vitro. We generated isogenic HG3-Cas9 CLL-derived cell lines harboring monoallelic del(11q) (targeting 11q22.1/11q23.3 regions) and further loss-of-function mutations in ATM and/or TP53 to mimic all the possible combinations observed in our CLL cohort. By proliferation assays, we noted that the introduction of TP53 mutations increased the proliferation rates in both HG3WT and HG3-del(11q) cells. In contrast, the introduction of an ATM truncating mutation on the remaining allele of the HG3-del(11q) TP53MUT clone, suppressed this proliferative advantage, with growth rates comparable to those of HG3-del(11q). Accordingly, DNA content analysis by propidium iodide revealed that cells harboring biallelic ATM and TP53 loss also showed mitotic and cell cycle defects. To further evaluate the implications of these alterations in the clonal dynamics of CLL in vivo, we performed fluorescence-based clonal competition experiments by injecting these edited cell lines intravenously into NGS mice. First, we observed that HG3-TP53MUT cells outgrew HG3WT cells in spleen of xenotransplanted mice 14 days after injection (P We next assessed whether these cell models could predict responses of these combined abnormalities to BTK and PI3K inhibitors. We observed that HG3-del(11q) TP53MUT and HG3-TP53MUT cells showed partial response to ibrutinib and idelalisib, although the IC50 values were still higher than the ones observed in HG3WT clones, especially with idelalisib (27.4 and 20.6 vs. 1.8 uM, respectively). Nonetheless, we found that HG3-del(11q) TP53MUT cells were highly sensitive to novel preclinical drugs that have been shown to be effective in TP53 deficient cells such ATR inhibitors, with an IC50 value comparable to HG3WT cells (mean IC50 0.55 vs. 0.67 uM) (Fig 1C). In summary, we show that mutations in TP53 can appear in a subset of monoallelic del(11q) CLL cases, conferring a synergistic clonal advantage in vivo, and therefore a dismal clinical impact on the OS of this CLL subgroup. In addition, the biological basis of mutual exclusivity of biallelic ATM and TP53 alterations in CLL was assessed, underscoring the importance of the number of alleles affected by these alterations, and establishing novel pre-clinical models for the study of the biology and therapeutic response of concurrent genetic abnormalities in the disease. Funding: PI18/01500 FI19/00191 CD19/00222 *MQA CPC equal contr Disclosures No relevant conflicts of interest to declare.

The deletion of 11q (del(11q)) invariably comprises ATM gene in chronic lymphocytic leukemia (CLL). Concomitant mutations in this gene in the remaining allele have been identified in 1/3 of CLL cases harboring del(11q), being the biallelic loss of ATM associated with adverse prognosis. Although the introduction of targeted BCR inhibition has significantly favored the outcomes of del(11q) patients, responses of patients harboring ATM functional loss through biallelic inactivation are unexplored, and the development of resistances to targeted therapies have been increasingly reported, urging the need to explore novel therapeutic approaches. Here, we generated isogenic CLL cell lines harboring del(11q) and ATM mutations through CRISPR/Cas9-based gene-editing. With these models, we uncovered a novel therapeutic vulnerability of del(11q)/ATM-mutated cells to dual BCR and PARP inhibition. Ex vivo studies in the presence of stromal stimulation on 38 CLL primary samples confirmed a synergistic action of the combination of olaparib and ibrutinib in del(11q)/ATM-mutated CLL patients. In addition, we showed that ibrutinib produced a homologous recombination repair impairment through RAD51 dysregulation, finding a synergistic link of both drugs in the DNA damage repair pathway. Our data provide a preclinical rationale for the use of this combination in CLL patients with this high-risk cytogenetic abnormality., This work was supported by grants from the Spanish Fondo de Investigaciones Sanitarias PI15/01471, PI18/01500, Instituto de Salud Carlos III (ISCIII), European Regional Development Fund (ERDF) “Una manera de hacer Europa”, “Consejería de Educación, Junta de Castilla y León” (SA271P18), “Proyectos de Investigación del SACYL”, Spain GRS 1847/A/18, GRS1653/A17,“Fundación Memoria Don Samuel Solórzano Barruso” (FS/23-2018), by grants (RD12/0036/0069) from Red Temática de Investigación Cooperativa en Cáncer (RTICC), Centro de Investigación Biomédica en Red de Cáncer (CIBERONC CB16/12/00233) and SYNtherapy “Synthetic Lethality for Personalized Therapy-based Stratification In Acute Leukemia” (ERAPERMED2018-275); ISCIII (AC18/00093). MQÁ is fully supported by an “Ayuda predoctoral de la Junta de Castilla y León” by the Fondo Social Europeo (JCYL-EDU/529/2017 PhD scholarship); MHS was supported by a grant from FEHH/Janssen (“Sociedad Española de Hematología y Hemoterapia”) and now holds a Sara Borrell postdoctoral contract (CD19/00222) from Instituto de Salud Carlos III (ISCIII), co-funded by Fondo Social Europeo (FSE) “El Fondo Social Europeo invierte en tu futuro”; AERV is supported with a research grant by FEHH (“Fundación Española de Hematología y Hemoterapia”); MG is supported by a Marie Curie Action International Outgoing Fellowship (PIOF-2013-624924); EtH is a Special Fellow of the Leukemia and Lymphoma Society (LLS) and a Scholar of the American Society of Hematology (ASH) and JLO is supported by a grant from the University of Salamanca (“Contrato postdoctoral programa II”).

Chronic lymphocytic leukemia (CLL) patients harboring 11q22.3 deletion, del(11q), are characterized by a rapid disease progression. One of the suggested genes to be involved in the pathogenesis of this deletion is BIRC3, a negative regulator of NF-κB, which is monoallelically deleted in ~80% of del(11q) CLL cases. In addition, truncating mutations in the remaining allele of this gene can lead to BIRC3 biallelic inactivation, which accounts for marked reduced survival in CLL. Nevertheless, the biological mechanisms by which monoallelic or biallelic BIRC3 lesions could contribute to del(11q) CLL pathogenesis, progression and therapy response are partially unexplored. We used the CRISPR/Cas9 system to model monoallelic and biallelic BIRC3 loss in vitro. First, we generated an isogenic HG3 CLL cell line harboring monoallelic del(11q) - HG3-del(11q) - by the introduction of 2 guide RNAs targeting 11q22.1 and 11q23.3 (~17 Mb). Loss-of-function BIRC3 mutations (MUT) were introduced in the remaining allele, generating 3 HG3-del(11q) BIRC3MUT clones. In addition, single BIRC3MUT were introduced in HG3 and MEC1 CLL-derived cells for experimental validation (n = 3 clones/cell line). We first questioned whether monoallelic and biallelic BIRC3 loss had an impact in the DNA-binding activity of NF-κB transcription factors. Interestingly, HG3-del(11q) had higher p52 and RelB (non-canonical NF-κB signaling) activity than HG3WT cells (P = 0.005; P = 0.007), being this activity further increased in HG3-del(11q) BIRC3MUT cells (P < 0.001; P < 0.001). In depth analysis of the non-canonical signaling components by immunoblot revealed that HG3-del(11q) and, to a greater extent, HG3-del(11q) BIRC3MUT cells presented NF-κB-inducing kinase (NIK) cytoplasmic stabilization, high p-IKKα levels and p52-RelB nuclear translocation. Besides, HG3-del(11q) BIRC3MUT cells showed increased levels of the anti-apoptotic proteins BCL2 and BCL-xL. We next assessed this pathway ex vivo in stroma and CpG-stimulated primary CLL cells with or without BIRC3 deletion (n = 22; 11 each group). Remarkably, stimulated BIRC3-deleted primary cells showed higher p52 and RelB activity than BIRC3WT cases (P = 0.01; P = 0.07), and the percentage of BIRC3-deleted cells correlated with p52 activity in del(11q) cases (P = 0.04). We further performed western blot analyses in a homogenous cohort of del(11q) cases including (n = 4) or not including (n = 3) BIRC3 within the deleted region. Interestingly, del(11q)/BIRC3 deleted cases presented high levels of stabilized NIK, which correlated with higher p52 processing (P = 0.003). These patients also showed higher BCL2 levels than those del(11q)/BIRC3 undeleted, and we could further observe a correlation between p52 and BCL2 levels (P = 0.01). Given this p52-dependent BCL2 upregulation, we treated the CRISPR/Cas9 edited clones with venetoclax, demonstrating that HG3-del(11q) BIRC3MUT cells were more sensitive upon BCL2 inhibition than HG3WT clones (mean IC50 3.5 vs. 5.75 μM; P = 0.005). In vitro proliferation assays were performed to interrogate the impact of BIRC3 loss in CLL cell growth, revealing that HG3 BIRC3MUT cell lines had higher growth rates than BIRC3WT cells (P = 0.001). HG3-del(11q) BIRC3MUT cells also showed enhanced proliferation in comparison to HG3-del(11q) clones (P = 0.009). We further determined the clonal dynamics of del(11q) and/or BIRC3MUT cell lines in clonal competition experiments, showing that HG3 BIRC3MUT and HG3-del(11q) BIRC3MUT cells progressively outgrew HG3WT and HG3-del(11q) cells, respectively, overtime (P = 0.02; P = 0.006). Furthermore, we injected these edited cell lines into NSG mice (n = 20) in vivo, showing that mice xenografted with HG3 BIRC3MUT and HG3-del(11q) BIRC3MUT cells presented, by flow cytometry, an increase of human CD45+ cells in spleen 14 days after injection, compared to HG3WT and HG3-del(11q) cells (P = 0.02; P = 0.015). In summary, this work demonstrates that biallelic BIRC3 deletion through del(11q) and mutation triggers non-canonical NF-κB signaling, driving BCL2 overexpression and conferring clonal advantage, which could account for the negative predictive impact of BIRC3 biallelic inactivation in CLL. Taken together, our results suggest that del(11q) CLL patients harboring BIRC3 mutations should be considered as a CLL subgroup at a high risk of progression that might benefit from venetoclax-based therapies. Funding: PI18/01500 Disclosures No relevant conflicts of interest to declare.

This study aims to investigate whether the heat treatment applied during the production of black onion, a novel derived product made from fresh onion, produces changes in the content of flavonoids, organosulfur compounds, organic acids, water soluble sugars and amino acids in three onion varieties (‘Shallot’, ‘Chata’ and ‘Echalion’). The total flavonoid content decreased up to 12-fold in black onions compared with fresh onions while the quantities of isoalliin, the main organosulfur compound in black onions, drastically increased during the process. Moreover, the levels of fructose and glucose significantly increased during the elaboration process, contributing to the sweetness of black onions. The influence of heating on their antioxidant capacity showed a decreasing trend of the ORAC antioxidant activity of onion, while ABTS and DPPH did not show a clear tendency. These results present a comprehensive phytochemical characterization of black onions, highlighting the significant influence of the heating process on their phytochemical composition.

Purpose: Endoglin (ENG; CD105) is a coreceptor of the TGFβ family that is highly expressed in proliferating endothelial cells. Often coopted by cancer cells, ENG can lead to neo-angiogenesis and vasculogenic mimicry in aggressive malignancies. It exists both as a transmembrane cell surface protein, where it primarily interacts with TGFβ, and as a soluble matricellular protein (sENG) when cleaved by matrix metalloproteinase 14 (MMP14). High ENG expression has been associated with poor prognosis in Ewing sarcoma, an aggressive bone cancer that primarily occurs in adolescents and young adults. However, the therapeutic value of ENG targeting has not been fully explored in this disease. Experimental Design: We characterized the expression pattern of transmembrane ENG, sENG, and MMP14 in preclinical and clinical samples. Subsequently, the antineoplastic potential of two novel ENG-targeting monoclonal antibody–drug conjugates (ADC), OMTX503 and OMTX703, which differed only by their drug payload (nigrin-b A chain and cytolysin, respectively), was assessed in cell lines and preclinical animal models of Ewing sarcoma. Results: Both ADCs suppressed cell proliferation in proportion to the endogenous levels of ENG observed in vitro. Moreover, the ADCs significantly delayed tumor growth in Ewing sarcoma cell line–derived xenografts and patient-derived xenografts in a dose-dependent manner. Conclusions: Taken together, these studies demonstrate potent preclinical activity of first-in-class anti-ENG ADCs as a nascent strategy to eradicate Ewing sarcoma.

Ewing sarcoma (ES) is an aggressive tumour affecting mainly children and young adults. When metastases are detected, the survival rate is compromised as a result of a lack of appropriated treatments. Balanced chromosomal translocations, present in all primary ES, originate gene fusions, such as EWSR1-FLI1, which act as aberrant transcription factors. Targeting EWSR1-FLI1 by using RNA interference approaches reduced tumour growth and tumourigenicity of ES cells in vitro and in vivo and is a good tool in order to get knowledge in the ES biology. However, possibility of taking RNA interference into clinic is limited. At present, some drugs affecting gene fusion activity have been reported to reduce tumour growth. In addition, several approaches targeting ES genetic alterations not related to gene fusions or their genetic targets have been recently reported. The use of more appropriated animal models and the study of ES tumour microenvironment and epigenetics will unveil new therapeutic targets. Key Concepts ES is an aggressive developmental tumour. Balanced chromosomal translocation and associated gene fusions are the primary molecular event in ES. Secondary molecular events in ES can define new therapeutic targets and new prognostic markers. The role played by epigenetics in ES and the regulation of chromatin remodelling is beginning to be known. Detection of ES circulating cells or identification of gene expression profiles in peripheral blood cells could become good prognostic markers. Identification of new markers of cancer stem cells could help improve ES therapy. Endoglin could be a relevant therapeutic target in ES. Osteolysis and bone remodelling are important mechanisms of ES tumour growth. ES cells secrete extracellular vesicles, containing aberrant EWSR1-FLI1 mRNA and other growth factors, which interact with surrounding tumour cells and extracellular matrix components. Combination therapy of a dual inhibitor of IGF1R and IR pathways and a DNA damage agent can avoid resistance to IGF1R inhibitors. At present, there is a lack of appropriate genetically engineered mice (GEM) of ES. Keywords: Ewing sarcoma; tumour microenvironment; exosome; endoglin; animal model; epigenetic

CRISPR/Cas9 technology was used to abrogate p210 oncoprotein expression in the Boff-p210 cell line, a pro-B line derived from interlukin-3-dependent Baf/3, that shows IL-3-independence arising from the constitutive expression of BCR-ABL p210. Using this approach, pools of Boff-p210-edited cells and single edited cell-derived clones were obtained and functionally studied in vitro. The loss of p210 expression in Boff-p210 cells resulted in the loss of ability to grow in the absence of IL-3, as the Baf/3 parental line, showing significantly increased apoptosis levels. Notably, in a single edited cell-derived clone carrying a frame-shift mutation that prevents p210 oncoprotein expression, the effects were even more drastic, resulting in cell death. These edited cells were injected subcutaneously in immunosuppressed mice and tumor growth was followed for three weeks. BCR/ABL-edited cells developed smaller tumors than those originating from unedited Boff-p210 parental cells. Interestingly, the single edited cell-derived clone was unable to develop tumors, similar to what is observed with the parental Baf/3 cell line. CRISPR/Cas9 genomic editing technology allows the ablation of the BCR/ ABL fusion gene, causing an absence of oncoprotein expression, and blocking its tumorigenic effects in vitro and in the in vivo xenograft model of CML. The future application of this approach in in vivo models of CML will allow us to more accurately assess the value of CRISPR/Cas9 technology as a new therapeutic tool that overcomes resistance to the usual treatments for CML patients., This work was supported in part by a grant from the Consejería de Educación, Junta de Castilla y León, Fondos FEDER (SA085U16 to JMHR and JCYL-EDU/346/2013 PhD scholarship to MHS), the ISCIII-FEDER Spanish Cancer Network (RD12/0036/0069) and the Fondo de Investigaciones Sanitarias (FIS) of the Spanish Ministry of Economy and Competitiveness and the European Regional Development Fund (ERDF) “Una manera de hacer Europa” (grant PI15/01471).

Cervical cancer and its precursors low-grade squamous intraepithelial lesions (LSIL) and high-grade squamous intraepithelial lesions (HSIL) are associated with infection by human papillomavirus (HPV), in particular HPV 16 and 18. The distribution of the HPV genotype varies with the severity of cervical disease, age and the geographic location of the patients. We report the results of a population study carried out in a region of north-western (NW) Spain aimed at determining the prevalence of single and multiple infections by 35 types of HPV using low-density microarrays for 113 cases with negative for intraepithelial lesions or malignancies; 588 with atypical squamous cells of undetermined significance (ASCUS)/LSIL; 183 with HSIL; and seven cases of squamous cell carcinomas. Of the 891 patients analysed, 50.2% had single infections and 49.8% had multiple HPV infections. In women aged below 30 years, there was a predominance of multiple infections (p = 0.027). ASCUS/LSIL was associated with multiple and HSIL with single infections (p = 0.025). We observed significant increases in the percentage of infections due to a high-risk (HR) type of HPV when the severity of the cytological lesion increased (p = 0.001). No relationship was found between greater aggressiveness in the cytological diagnosis and a higher number of HPV types involved in multiple infections. The five most frequent genotypes were HPV 16 (26.3%), 53 (18.2%), 51 (17.3%), 6 (14.8%) and 66 (13.1%). The prevalence of HPV 16, 33 and 58 increased significantly from ACUS/LSIL to HSIL and the prevalence of HPV 51, 53 and 66 decreased. HPV 16 was the only genotype that showed a significant increase in prevalence when the severity of the cytological disease increased in single infections (p = 0.0001). The implementation of bivalent prophylactic vaccination could potentially lead to prevention in 32% of the population included in the study - in at least a quarter of patients with ACUS/LSIL (26.7%), and in half of HSIL (50.2%).

Chromosome 11q22.3 deletion (del(11q)) is one of the most common cytogenetic alterations in CLL and usually involves both ATM and BIRC3 genes. Concomitant mutations in ATM and/or BIRC3 in the remaining allele have been associated with poor survival. Despite the encouraging efficacy of novel agents targeting BCR and BCL2 pathways, del(11q) patients still have an inferior outcome and the development of resistance to these drugs has been increasingly reported. We therefore investigated the functional impact of del(11q) together with loss-of-function mutations in ATM and/or BIRC3 and whether CLLs harboring these alterations could benefit from novel combinatorial therapies. To address these questions, we used the CRISPR/Cas9 system to generate an isogenic CLL cell line to model del(11q) derived from HG3 cells by introducing two guide RNAs targeting the 11q22.1 and 11q23.3 regions. The presence of a monoallelic deletion (size ~17 Mb) was confirmed in 100% of the cells by FISH. Truncating mutations in ATM and/or BIRC3 were introduced in the remaining allele, generating HG3 del(11q) ATMKO, del(11q) BIRC3KO and del(11q) ATMKOBIRC3KO (three clones per condition). In addition, single ATMKO and BIRC3KO mutations, or the combination of both, were introduced into both HG3 and MEC1 CLL-derived cells (three clones per condition). Functional in vitro studies revealed that del(11q) BIRC3KO cells had increased growth rates compared to del(11q) BIRC3WT clones (P We next assessed the response of these CRISPR/Cas9-edited CLL cell lines to therapy. Of note, only TP53KO clones (also generated by CRISPR/Cas9), and not del(11q) BIRC3KO cells, showed resistance to fludarabine (mean IC50 16.9 uM vs. 4.1 uM; mean apoptotic cells (5 uM) 5.5% vs. 22.5%; P Moreover, IBRU potentiated the effects of OLA in cell viability (72h) in all the del(11q) clones (combination indexes 0.69-0.85), leading to an increased necrotic cell death, as shown by annexin V/PI staining (P In conclusion, we demonstrate that del(11q) CLL cells with biallelic inactivation of BIRC3 and ATM show enhanced proliferation through activation of the non-canonical NF-kB pathway, and accumulation of DNA damage contributing to genomic instability. We show that these defects on the DDR can be therapeutically targeted by synthetic lethal approaches using PARP inhibitors either alone or in combination with BCR inhibitors, providing a rationale for the study of this combination in relapsed del(11q) CLL patients. PI15/01471 SA085U16 JCyL-MQ FEHH-MH Disclosures García-Tuñón: Novartis: Research Funding. Wu:Neon Therapeutics: Equity Ownership.

Carcinoma in situ (CIS) is a non-papillary high-grade, potentially aggressive, and unpredictable manifestation of bladder urothelial carcinoma. The aim of this study was to assess patterns of Cyclin D3 gene amplification in Bacillus Calmette-Guerin (BCG)-treated CIS and correlate gene status with recurrence-free and progression-free survival. A sequential cohort series of 28 primary (isolated) or secondary (concomitant) bladder CIS samples in which there was enough tissue material to assess Cyclin D3 gene status by fluorescent in situ hybridization was the study group. Cyclin D3 gene amplification was present in 29% of secondary CIS; none of primary CIS samples had Cyclin D3 gene amplification. Cyclin D3 amplification was related to recurrence- (p=0.046) and progression-free survival (p=0.002). Type of bladder CIS (primary vs. secondary) was unrelated to recurrence- or progression-free survival in the current series. Cox's regression analysis selected Cyclin D3 as an independent predictor of progression-free survival (p=0.041, relative risk=61.503, 95% confidence interval=1.1-274.710). None of primary CIS cases recurred on follow-up; nine secondary CIS recurred and four of them progressed to invasive bladder carcinoma HG T1 (n=1), T2b N0M0 (n=1), T3b N1M0 (n=1) and T4aN1M1 (n=1). Mean recurrence±SD (months) occurred at 19.5±2.06 (95% (confidence interval (CI)), 15.5-23.6); mean progression (months) occurred at 23.8±1.46 (95% (CI), 20.9-26.7). Our study suggests that Cyclin D3 gene amplification might be a predictor of aggressiveness in BCG-treated CIS. © 2010 Springer-Verlag., Supported by the grants SAF2007-64942 (Ministry of Education and Research, Madrid, Spain), P07-CVI-02974 and PI0003/2007 (Junta de Andalucia, Seville, Spain). Work at CIC is also funded by Instituto de Salud Carlos III (PI081828, RD06/020/0059). JLO is supported by ISCIII (Contratos Postdoctorales Sara Borrell CD6/00001).

Purpose: Goal of this study was to identify mechanisms that limit efficacy of trabectedin (ET-743, Yondelis) in Ewing sarcoma (EWS), so as to develop a clinical applicable combination therapy. Experimental Design: By chromatin immunoprecipitation, we analyzed EWS–FLI1 binding to the promoters of several target genes, such as TGFβR2, CD99, insulin-like growth factor receptor 1 (IGF1R), and IGF1, both in vitro and in xenografts treated with trabectedin or doxorubicin. Combined therapy with trabectedin and anti-IGF1R agents (AVE1642 HAb; OSI-906) was tested in vitro and in xenografts. Results: We confirm that both trabectedin and doxorubicin were able to strongly reduce EWS–FLI1 (both type I and type II) binding to two representative target genes (TGFβR2 and CD99), both in vitro and in xenografts. However, trabectedin, but not doxorubicin, was also able to increase the occupancy of EWS–FLI1 to IGF1R promoters, leading to IGF1R upregulation. Inhibition of IGF1R either by the specific AVE1642 human antibody or by the dual IGF1R/insulin receptor inhibitor OSI-906 (Linsitinib) greatly potentiate the efficacy of trabectedin in the 13 EWS cell lines here considered as well as in TC-71 and 6647 xenografts. Combined therapy induced synergistic cytotoxic effects. Trabectedin and OSI-906 deliver complementary messages that likely converge on DNA-damage response and repair pathways. Conclusions: We showed that trabectedin may not only inhibit but also enhance the binding of EWS–FLI1 to certain target genes, leading to upregulation of IGF1R. We here provide the rationale for combining trabectedin to anti-IGF1R inhibitors. Clin Cancer Res; 21(6); 1373–82. ©2015 AACR.

Producción Científica, Recent preclinical evidence has suggested that Ewing Sarcoma (ES) bearing EWSR1-ETS fusions could be particularly sensitive to PARP inhibitors (PARPinh) in combination with DNA damage repair (DDR) agents. Trabectedin is an antitumoral agent that modulates EWSR1-FLI1 transcriptional functions, causing DNA damage. Interestingly, PARP1 is also a transcriptional regulator of EWSR1-FLI1, and PARPinh disrupts the DDR machinery. Thus, given the impact and apparent specificity of both agents with regard to the DNA damage/DDR system and EWSR1-FLI1 activity in ES, we decided to explore the activity of combining PARPinh and Trabectedin in in vitro and in vivo experiments. The combination of Olaparib and Trabectedin was found to be highly synergistic, inhibiting cell proliferation, inducing apoptosis, and the accumulation of G2/M. The drug combination also enhanced γH2AX intranuclear accumulation as a result of DNA damage induction, DNA fragmentation and global DDR deregulation, while EWSR1-FLI1 target expression remained unaffected. The effect of the drug combination was corroborated in a mouse xenograft model of ES and, more importantly, in two ES patient-derived xenograft (PDX) models in which the tumors showed complete regression. In conclusion, the combination of the two agents leads to a biologically significant deregulation of the DDR machinery that elicits relevant antitumor activity in preclinical models and might represent a promising therapeutic tool that should be further explored for translation to the clinical setting., Ministerio de Economía y Competitividad (PI081828), Ministerio de Economía y Competitividad (RD06/0020/0059 ), Ministerio de Economía y Competitividad (RD12/0036/0017), Ministerio de Economía y Competitividad (PT13/0010/0056)

Recent preclinical evidence has suggested that Ewing Sarcoma (ES) bearing EWSR1-ETS fusions could be particularly sensitive to PARP inhibitors (PARPinh) in combination with DNA damage repair (DDR) agents. Trabectedin is an antitumoral agent that modulates EWSR1-FLI1 transcriptional functions, causing DNA damage. Interestingly, PARP1 is also a transcriptional regulator of EWSR1-FLI1, and PARPinh disrupts the DDR machinery. Thus, given the impact and apparent specificity of both agents with regard to the DNA damage/DDR system and EWSR1-FLI1 activity in ES, we decided to explore the activity of combining PARPinh and Trabectedin in in vitro and in vivo experiments. The combination of Olaparib and Trabectedin was found to be highly synergistic, inhibiting cell proliferation, inducing apoptosis, and the accumulation of G2/M. The drug combination also enhanced γH2AX intranuclear accumulation as a result of DNA damage induction, DNA fragmentation and global DDR deregulation, while EWSR1-FLI1 target expression remained unaffected. The effect of the drug combination was corroborated in a mouse xenograft model of ES and, more importantly, in two ES patient-derived xenograft (PDX) models in which the tumors showed complete regression. In conclusion, the combination of the two agents leads to a biologically significant deregulation of the DDR machinery that elicits relevant antitumor activity in preclinical models and might represent a promising therapeutic tool that should be further explored for translation to the clinical setting.

Ewing Sarcoma is a developmental tumor characterized by balanced chromosomal translocations and formation of new fusion genes, which are the main hallmark of this rare entity. Despite the vast knowledge regarding the molecular aspects of this rare malignancy obtained in the last few years, including the discovery of new therapeutic targets, many questions still remain open. In this review we focus on the research on targeted therapies in this malignancy, and discussed some bottlenecks related to this such as the possible role of pathologists, the availability of samples, the lack of appropriate animal models, and the resources needed to carry out preclinical and clinical research.

The European Food Safety Authority (EFSA) has accepted health claims for the food constituent melatonin because scientific evidence shows that it is effective at reducing sleep onset latency, and that it alleviates subjective feelings of jet lag. According to risk assessment data published by EFSA in 2011, histamine and tyramine are the most toxic biogenic amines and the ones that most affect food safety. The potential formation of biogenic amines is a concern in fermented foods because of the intense microbial activity. Conversely, Saccharomyces cerevisiase produces melatonin during fermentation in the winemaking process. This study aims to evaluate the production of potentially healthy melatonin and toxic biogenic amines during the winemaking process. To this end, 11 biogenic amines (agmatine, cadaverine, histamine, methylamine, 2-phenylethylamine, putrescine, spermidine, spermine, tyramine, tryptamine and melatonin) have been monitored during the making of 5 monovarietal wines (Merlot, Palomino Fino, Syrah, Tempranillo and Tintilla de Rota). This paper shows that alcoholic and malolactic fermentation plays a crucial role in the formation of these compounds. Bioactive melatonin is formed at safe levels of the other biogenic amines.

Neuroblastic tumors (NTs) include the neuroblastomas, ganglioneuroblastomas and ganglioneuromas. We have reported previously that the calcium-sensing receptor is expressed in differentiated, favorable NTs but almost undetectable in unfavorable neuroblastomas. We have now detected hypermethylation of a particular region within the CpG island encompassing the CaSR gene promoter 2 in neuroblastoma cell lines and 25% primary neuroblastomas. Hypermethylation of this region was associated with reduced CaSR messenger RNA expression and several predictors of poor outcome in neuroblastomas, including MYCN amplification. Treatment with 5'aza-2-deoxycitidine and/or trichostatin A restored CaSR expression in MYCN-amplified cell lines. Following 5'aza-2-deoxycitidine exposure, decreased percentages of methylated CpG sites were observed at the above-mentioned region. By interphase fluorescence in situ hybridization, variable percentages of nuclei with monosomy of chromosome 3, where the human CaSR gene resides, were observed in more than 90% of primary NTs of all subgroups. Nuclei harboring this alteration were heterogeneously distributed among tumor cells. Ectopic overexpression of the calcium-sensing receptor in two MYCN-amplified neuroblastoma cell lines in which this gene is silenced by promoter hypermethylation significantly reduced their in vitro proliferation rates and almost abolished their capacity to generate xenografts in immunocompromised mice. Finally, upon acute exposure to calcium, the primary activator of this receptor, calcium-sensing receptor-overexpressing neuroblastoma cells underwent apoptosis, a process dependent on sustained activation of ERK1/2. These data would support the hypothesis that epigenetic silencing of the CaSR gene is neither an in vitro artefact in neuroblastoma cell lines nor an irrelevant, secondary event in primary NTs, but a significant mechanism for neuroblastoma survival., Fundació Privada Cellex (CdT); Instituto de Salud Carlos III (CD6/00001 to J.L.O).

This paper reports the determination of biogenic amines by high-performance liquid chromatography (HPLC) and fluorescence detection after derivatization with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC) in balsamic, apple, and red, white, and Sherry wine vinegars. A solid-phase extraction (SPE) with mixed-mode resins method was used before analysis. The method was successfully validated obtaining adequate values of selectivity, response linearity, precision, accuracy, and low detection and quantification limits. The total content of biogenic amines in vinegars ranged from 23.35 to 1445.2 μg/L, being lower than those reported in wines. Putrescine was the amine that showed the highest concentrations in most samples. Methylamine and phenylethylamine were not determined in any vinegar. Balsamic and "Pedro Ximenez" Sherry vinegars reached the highest amounts of biogenic amines, while apple, white and Sherry wine vinegars had the lowest concentrations. Principal component analysis using the biogenic amines as variables, allowed to separate the different kind of vinegars, excepting red vinegars.

Receptor endocytosis is critical for cell signaling. IGF1R mediates an autocrine loop that is de-regulated in Ewing Sarcoma (ES) cells. Here we study the impact of IGF1R internalization, mediated by clathrin and caveolin-1 (CAV1), in ES signaling. We used clathrin and CAV1-siRNA to interfere in clathrin- and caveolin-dependent endocytosis. Chlorpromazine (CPMZ) and methyl-beta-cyclo-dextrin (MCD) were also used in order to inhibit clathrin- and caveolin-dependent endocytosis, respectively. We analyzed IGF1R internalization and co-localization with clathrin and CAV1 upon ligand binding, as well as the status of the IGF1R pathway, cellular proliferation, and the apoptosis of interfered and inhibited ES cells. We performed a high-throughput tyrosine kinase phosphorylation assay to analyze the effects of combining the IGF1R tyrosine kinase inhibitor AEW541 (AEW) with CPMZ or MCD on the intracellular phospho-proteome. We observed that IGF1R is internalized upon ligand binding in ES cells and that this process is dependent on clathrin or CAV1. The blockage of receptor internalization inhibited AKT and MAPK phosphorylation, reducing the proliferative rate of ES cells and increasing the levels of apoptosis. Combination of AEW with CPMZ or MCD largely enhanced these effects. CAV1 and clathrin endocytosis controls IGF1R internalization and signaling and has a profound impact on ES IGF1R-promoted survival signaling. We propose the combination of tyrosine-kinase inhibitors with endocytosis inhibitors as a new therapeutic approach to achieve a stronger degree of receptor inhibition in this, or other neoplasms dependent on IGF1R signaling., Funding provided by EuroBoNet, the European research network on bone tumors (FP6-2004-Lifescihealth-5, proposal number 018814)-European Commission and the Instituto de Salud Carlos Tercero, FIS- project PI081828. J.L. Ordóñez is supported by the ISCIII (Contratos Perfeccionamiento CD6/00001). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript., Funding provided by EuroBoNet, the European research network on bone tumors (FP6-2004-Lifescihealth-5, proposal number 018814)-European Commission and the Instituto de Salud Carlos Tercero, FIS- project PI081828. J.L. Ordo´n˜ ez is supported by the ISCIII (Contratos Perfeccionamiento CD6/00001). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Ewing sarcoma family tumors (ESFT) are a group of aggressive solid bone and soft tissue malignancies of children and young adults characterized by specific chromosomal translocations that give rise to EWS-ETS aberrant transcription factors. Identification of EWS-ETS target genes and their role in tumor signaling networks together with the unravelling of the cell of origin will facilitate the translation into new treatment modalities for these neoplasms, CIC-IBMCC belongs to NoE Eurobonet, FP6-2004- Lifescihealth-5, proposal number 018814, European Commission. Work at CIC is also funded by Instituto de Salud Carlos III, Spanish Ministry of Science and Innovation-FEDER (PI052524; RD06/0020/0059, CD06/00001). This work has been done with the support of the Fundación Memoria D. Samuel Solórzano Barruso.

Bone and soft tissue sarcomas are an infrequent and heterogeneous group of mesenchymal tumors including more than a hundred different entities attending to histologic patterns. Research into the molecular aspects of sarcomas has increased greatly in the last few years. This enormous amount of knowledge has allowed, for instance, to refine the classification of sarcomas, improve the diagnosis, and increase the number of therapeutical targets available, most of them under preclinical evaluation. However, other important key issues, such as sarcomagenesis and the cell of origin of sarcomas, remain unresolved. From a molecular point of view, these neoplasias are grouped into 2 main types: (a) sarcomas showing relatively simple karyotypes and translocations, which originate gene fusions (eg, EWS-FLI1 in Ewing sarcoma) or point mutations (eg, c-kit in the gastrointestinal tumors) and (b) sarcomas showing unspecific gene alterations, very complex karyotypes, and no translocations. The discovery of the early mechanisms involved in the genesis of sarcomas, the more relevant signaling pathways, and the development of genetically engineered mouse models could also provide a new individualized therapeutic strategy against these tumors. This review describes the clinical application of some of the molecular alterations found in sarcomas, some advances in the field of sarcomagenesis, and the development of animal models.

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License.-- et al., [BACKGROUND]: Ewing sarcoma is a paradigm of solid tumour -bearing chromosomal translocations resulting in fusion proteins that act as deregulated transcription factors. Ewing sarcoma translocations fuse the EWS gene with an ETS transcription factor, mainly FLI1. Most of the EWS-FLI1 target genes still remain unknown and many have been identified in heterologous model systems. [METHODS]: We have developed a stable RNA interference model knocking down EWS-FLI1 in the Ewing sarcoma cell line TC71. Gene expression analyses were performed to study the effect of RNA interference on the genetic signature of EWS-FLI1 and to identify genes that could contribute to tumourigenesis. [RESULTS]: EWS-FLI1 inhibition induced apoptosis, reduced cell migratory and tumourigenic capacities, and caused reduction in tumour growth. IGF-1 was downregulated and the IGF-1/IGF-1R signalling pathway was impaired. PBK/TOPK (T-LAK cell-originated protein kinase) expression was decreased because of EWS-FLI1 inhibition. We showed that TOPK is a new target gene of EWS-FLI1. TOPK inhibition prompted a decrease in the proliferation rate and a dramatic change in the cell's ability to grow in coalescence. [CONCLUSION]: This is the first report of TOPK activity in Ewing sarcoma and suggests a significant role of this MAPKK-like protein kinase in the Ewing sarcoma biology. © 2009 Cancer Research., CIC-IBMCC and HHU belong to NoE Eurobonet, FP6-2004-Lifescihealth-5, proposal number 018814, European Commission. Work at CIC is also funded by Instituto de Salud Carlos III, Spanish Ministry of Science and Innovation-FEDER (PI052524; RD06/0020/0059, CD6/ 00001). Herrero-Martín was a recipient of a pre-doctoral fellowship from the Departamento de Educación, Junta de Castilla y León, Spain. This work has been done within the Acción Transversal en Cáncer program and the cooperative agreement between ISCIII and FICUS.

Ewing's sarcoma family tumors (EFT) are characterized by specific chromosomal translocations, which lead to EWS/ETS transcription factors.Elucidation of EWS/ETS target gene networks within the context of other signaling pathways, together with the identification of the initiating cell, and the development of genetically engineered mice will hopefully lead to biology-based therapeutic strategies for these tumors. 2009 American Association for Cancer Research., Grant support: The Centro de Investigación del Cáncer participates in EuroBoNeT, the European research network on bone tumors (FP6-2004-Lifescihealth-5, proposal number 018814)-European Commission. The Laboratory of Molecular Pathology of Sarcomas is also supported by the Spanish Ministry of Science and Innovation (FIS-FEDER, PI081828)and by the Junta de Castilla y León (SAN 673/SA 37/08). J. L. Ordóñez is supported by ISCIII (Contratos Perfeccionamiento CD6/00001); D. Osuna is supported by EuroBoNeT; J. Madoz-Gúrpide is supported by the Spanish Ministry of Science and Innovation, Ramón y Cajal Program.

Ewing Sarcoma (ES) shows several deregulated autocrine loops mediating cell survival and proliferation. Therefore, their blockade is a promising therapeutic approach. We previously reported the in vitro effect of insulin-like growth factor 1 receptor (IGF1R)/KIT pathway blockade on ES cell lines, and we now extend our observations to changes induced by this treatment in interacting proteins/networks. A proteomic analysis revealed that Heat Shock Protein (HSP)90 was differentially expressed between ES cell lines sensitive and resistant to specific IGF1R/KIT inhibitors. We therefore inhibited HSP90 with 17-allylamino-17-demethoxygeldanamycin (17-AAG) and siRNA, and observed that ES cell line growth and survival were reduced, especially in the resistant cell lines. Conversely, HSP90 induced-expression conferred resistance to anti-IGF1R/KIT treatment in the sensitive cell lines. 17-AAG treatment induced HSP90 client protein degradation, including AKT, KIT, or IGF1R, by inhibiting their physical interaction with HSP90. Xenograft models developed with A673 ES cell line confirmed that HSP90 inhibition, alone or combined with IGF1R inhibition, significantly reduced tumor growth and expression of client proteins. Remarkably, using two independent clinical sample sets, we have found that nearly half of IGF1R-positive tumors also show HSP90 overexpression. This delineates a subset of patients that could benefit from combination of anti-HSP90 agents when considering IGF1R-targeting therapies. Importantly, sensitivity to drugs such as ADW/IMA depends not only on the levels of expression and basal activation of IGF1R/KIT, but also, and for the first time reported in ES, on the development of the stress response mechanism. Accordingly, HSP90 expression could be a predictive factor of response to IGF1R-targeting therapies. ©2008 American Association for Cancer Research., Support was given by Fundación Ramón Areces, and Spanish Ministry of Health (FIS-FEDER: PI052524;ISCIII: CD6/00001), Centro de Investigación del Cáncer and Heinrich-Heine University belong to EuroBoNet, the European research network on bone tumors (FP6-2004-Lifescihealth-5, proposal number 018814)-European Commission, and by III Quadro Comunitário de Apoio, from the European Social Fund and Portuguese National Funds of MCES (A.S. Martins).

Bone and soft tissue sarcomas are an infrequent and heterogeneous group of mesenchymal tumors, including more than a hundred different entities attending to histological patterns. Sarcomas are quite resistant to conventional chemotherapy (anthracycline and ifosfamide) with the exception of some subtypes, such as Ewing's sarcoma (ES). New drugs with proved efficacy against sarcomas include taxanes, gemcitabine, and ET-743. Preclinical studies have also identified key molecular events leading to the progression and development of sarcomas which are good candidates to targeted therapy. Inhibitors of the tyrosine kinase receptors, such as IGF-1R, c-kit, PDGFR, VEGFR, or the mTOR signaling pathway, proteasome, angiogenesis, and stress response proteins are under clinical evaluation against sarcomas. ES, a tumor characterized by chromosomal translocations that originate gene fusions (EWS-FLI1, EWS-ERG), is an example of a good chemotherapy responder tumor whose survival rate shows a plateau in recent years. Preclinical studies have identified that new targets such as HSP90 are of relevance to ES. On the other hand, recent studies showed the role of cancer stem cells (CSCs) in sarcomas and the relevance of the identification of reliable molecular markers and possible therapeutic targets. New therapeutic approaches could be directed against CSCs. This review describes more recent targeted therapy in sarcomas, with special emphasis on ES and the role of CSCs. We also emphasize the role of high throughput proteomic techniques in identifying new therapeutic targets. © 2008 Elsevier Inc. All rights reserved.

Amaral, Ana Teresa et al., [Background] Ewing Sarcoma (EWS) is a mesenchymal-derived tumor that generally arises in bone and soft tissue. Intensive research regarding the pathogenesis of EWS has been insufficient to pinpoint the early events of Ewing sarcomagenesis. However, the Mesenchymal Stem Cell (MSC) is currently accepted as the most probable cell of origin., [Materials and Methods] In an initial study regarding a deep characterization of MSC obtained specifically from EWS patients (MSC-P), we compared them with MSC derived from healthy donors (MSC-HD) and EWS cell lines. We evaluated the presence of the EWS-FLI1 gene fusion and EWSR1 gene rearrangements in MSC-P. The presence of the EWS transcript was confirmed by q-RT-PCR. In order to determine early events possibly involved in malignant transformation, we used a multiparameter quantitative strategy that included both MSC immunophenotypic negative/positive markers, and EWS intrinsic phenotypical features. Markers CD105, CD90, CD34 and CD45 were confirmed in EWS samples., [Results] We determined that MSC-P lack the most prevalent gene fusion, EWSR1-FLI1 as well as EWSR1 gene rearrangements. Our study also revealed that MSC-P are more alike to MSC-HD than to EWS cells. Nonetheless, we also observed that EWS cells had a few overlapping features with MSC. As a relevant example, also MSC showed CD99 expression, hallmark of EWS diagnosis. However, we observed that, in contrast to EWS cells, MSC were not sensitive to the inhibition of CD99. [Conclusions] In conclusion, our results suggest that MSC from EWS patients behave like MSC-HD and are phenotypically different from EWS cells, thus raising important questions regarding MSC role in sarcomagenesis. © 2014 Amaral et al., Enrique de Álava's lab is also sourced by the Red Temática de investigación del cáncer (RTICC, Spain). Katia Scotlandi's lab is also sourced by the Italian Association for cancer research (AIRC IG10452).