Suchergebnisse

Oncolytic virotherapy represents a promising alternative for cancer treatment; however, viral delivery to the tumor represents a major challenge. Mesenchymal stem cells (MSCs) chemotax to tumors, and can serve as a viral delivery tool. Previously, we demonstrated antitumor therapeutic efficacy for mesenchymal stem cells (MSCs) infected with the oncolytic human adenovirus ICOVIR5 (Celyvir) for treatment of neuroblastoma patients. Given the lack of suitable immunocompetent preclinical models, the mechanism underlying Celyvir antitumor activity remains unknown. In this study, we used the syngeneic murine CMT64 cell line as a human adenovirus-semi-permissive tumor model and demonstrate the homing capacity of mouse Celyvir (mCelyvir) to CMT64 tumors. We found that the combined treatment of mCelyvir and intratumoral injections (i.t.) of ICOVIR5 was more effective than treatment with i.t. ICOVIR5 alone. Interestingly, the superior therapeutic effect of the combined therapy was associated with a higher tumor infiltration of CD8+ and CD4+ T cells. Our findings suggest that the use of MSCs as carriers of oncolytic adenovirus can improve the clinical efficacy of anti-cancer virotherapy, not only by driving the adenovirus to tumors, but also through their potential to recruit T cells. ; This work was supported by grants from the Fondo de Investigaciones Sanitarias (PI05/2217; PI08/0029; PI14CIII/00005), RTICC (RD12/0036/0015; RD12/0036/0027) and the Madrid Regional Government (S-BIO-0204-2006, MesenCAM; P2010/BMD-2420, CellCAM) in Spain to JG-C. ER and TC are supported by the "Sara Borrell" program of the Instituto de Salud Carlos III. The experiments were approved by the appropriate committees. ; Sí

Due to compromised homologous recombination (HR) repair, BRCA1- and BRCA2-mutated tumours accumulate DNA damage and genomic rearrangements conducive of tumour progression. To identify drugs that target specifically BRCA2-deficient cells, we screened a chemical library containing compounds in clinical use. The top hit was chlorambucil, a bifunctional alkylating agent used for the treatment of chronic lymphocytic leukaemia (CLL). We establish that chlorambucil is specifically toxic to BRCA1/2-deficient cells, including olaparib-resistant and cisplatin-resistant ones, suggesting the potential clinical use of chlorambucil against disease which has become resistant to these drugs. Additionally, chlorambucil eradicates BRCA2-deficient xenografts and inhibits growth of olaparib-resistant patient-derived tumour xenografts (PDTXs). We demonstrate that chlorambucil inflicts replication-associated DNA double-strand breaks (DSBs), similarly to cisplatin, and we identify ATR, FANCD2 and the SNM1A nuclease as determinants of sensitivity to both drugs. Importantly, chlorambucil is substantially less toxic to normal cells and tissues in vitro and in vivo relative to cisplatin. Because chlorambucil and cisplatin are equally effective inhibitors of BRCA2-compromised tumours, our results indicate that chlorambucil has a higher therapeutic index than cisplatin in targeting BRCA-deficient tumours. ; This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska‐Curie grant agreement No. 722729. Research in M.T. laboratory is supported by Cancer Research UK, Medical Research Council and University of Oxford.

Compounds with specific cytotoxic activity in senescent cells, or senolytics, support the causal involvement of senescence in aging and offer therapeutic interventions. Here we report the identification of Cardiac Glycosides (CGs) as a family of compounds with senolytic activity. CGs, by targeting the Na+/K+ATPase pump, cause a disbalanced electrochemical gradient within the cell causing depolarization and acidification. Senescent cells present a slightly depolarized plasma membrane and higher concentrations of H+, making them more susceptible to the action of CGs. These vulnerabilities can be exploited for therapeutic purposes as evidenced by the in vivo eradication of tumors xenografted in mice after treatment with the combination of a senogenic and a senolytic drug. The senolytic effect of CGs is also effective in the elimination of senescence-induced lung fibrosis. This experimental approach allows the identification of compounds with senolytic activity that could potentially be used to develop effective treatments against age-related diseases. ; We thank Matthias Drosten, Alejo Efeyan and Sean Morrison for plasmids. F.T-M. is a postdoctoral fellow from CONACYT (cvu 268632); P.P. is a predoctoral fellow from Xunta de Galicia; M.C. is a "Miguel Servet II" investigator (CPII16/00015). P.P.-R. receives support from a program by the Deputacion de Coruna (BINV-CS/2019). Work in the laboratory of M.C. is funded by grant RTI2018-095818-B-100 (MCIU/AEI/FEDER, UE). P.J.F.-M. is funded by the IMDEA Food Institute, the Ramon Areces Foundation, (CIVP18A3891), and a Ramon y Cajal Award (MICINN) (RYC-2017-22335). M.P.I. is funded by Talento Modalidad-1 Program Grant, Madrid Regional Government (#2018-T1/BIO-11262). F.P. was funded by a Long Term EMBO Fellowship (ALTF-358-2017) and F.H-G. was funded by the PhD4MD Programme of the IRB, Hospital Clinic and IDIBAPS. Work in the laboratory of M.S. was funded by the IRB and by grants from the Spanish Ministry of Economy co-funded by the European Regional Development Fund (ERDF) (SAF2013-48256-R), the European Research Council (ERC-2014-AdG/669622), and "laCaixa" Foundation. ; Sí

Qingyi He,2,* Xiaohui Wang,3,* Xing Zhang,4 Huifang Han,4 Baosan Han,5 Jianzhong Xu,2 Kanglai Tang,2 Zhiren Fu,1 Hao Yin1,4 1Department of Surgery, Organ Transplant Center, Shanghai Changzheng Hospital, Shanghai Second Military Medical School, 2Department of Orthopedic Surgery, Southwest Hospital, Third Military Medical University, Chongqing, 3Department of General Surgery, Bayinguoleng Mengguzizhizhou People's Hospital, Korla, Xinjiang, People's Republic of China; 4Department of Surgery, The University of Chicago, Chicago, IL, USA; 5Department of Surgery, Shanghai Xinhua Hospital, Shanghai, People's Republic of China*These authors contributed equally to this workAbstract: The traditional xenograft subcutaneous pancreatic cancer model is notorious for its low incidence of tumor formation, inconsistent results for the chemotherapeutic effects of drug molecules of interest, and a poor predictive capability for the clinical efficacy of novel drugs. These drawbacks are attributed to a variety of factors, including inoculation of heterogeneous tumor cells from patients with different pathological histories, and use of poorly defined Matrigel®. In this study, we aimed to tissue-engineer a pancreatic cancer model that could readily cultivate a pancreatic tumor derived from highly homogenous CD24+CD44+ pancreatic cancer stem cells delivered by a well defined electrospun scaffold of poly(glycolide-co-trimethylene carbonate) and gelatin. The scaffold supported in vitro tumorigenesis from CD24+CD44+ cancer stem cells for up to 7 days without inducing apoptosis. Moreover, CD24+CD44+ cancer stem cells delivered by the scaffold grew into a native-like mature pancreatic tumor within 8 weeks in vivo and exhibited accelerated tumorigenesis as well as a higher incidence of tumor formation than the traditional model. In the scaffold model, we discovered that oxaliplatin-gemcitabine (OXA-GEM), a chemotherapeutic regimen, induced tumor regression whereas gemcitabine alone only capped tumor growth. The mechanistic study attributed the superior antitumorigenic performance of OXA-GEM to its ability to induce apoptosis of CD24+CD44+ cancer stem cells. Compared with the traditional model, the scaffold model demonstrated a higher incidence of tumor formation and accelerated tumor growth. Use of a tiny population of highly homogenous CD24+CD44+ cancer stem cells delivered by a well defined scaffold greatly reduces the variability associated with the traditional model, which uses a heterogeneous tumor cell population and poorly defined Matrigel. The scaffold model is a robust platform for investigating the antitumorigenesis mechanism of novel chemotherapeutic drugs with a special focus on cancer stem cells.Keywords: pancreatic cancer, cancer stem cell, electrospun scaffold, gemcitabine, oxaliplatin

Glutamoptosis is the induction of apoptotic cell death as a consequence of the aberrant activation of glutaminolysis and mTORC1 signaling during nutritional imbalance in proliferating cells. The role of the bioenergetic sensor AMPK during glutamoptosis is not defined yet. Here, we show that AMPK reactivation blocks both the glutamine-dependent activation of mTORC1 and glutamoptosis in vitro and in vivo. We also show that glutamine is used for asparagine synthesis and the GABA shunt to produce ATP and to inhibit AMPK, independently of glutaminolysis. Overall, our results indicate that glutamine metabolism is connected with mTORC1 activation through two parallel pathways: an acute alpha-ketoglutarate-dependent pathway; and a secondary ATP/AMPK-dependent pathway. This dual metabolic connection between glutamine and mTORC1 must be considered for the future design of therapeutic strategies to prevent cell growth in diseases such as cancer. ; This work was supported by funds from the following institutions: Agencia Estatal de Investigación/European Regional Development Fund, European Union (PGC2018-096244- B-I00, SAF2016-75442-R), Ministry of Science, Innovation and Universities of Spain, Spanish National Research Council—CSIC, Institut National de la Santé et de la Recherche Médicale —INSERM, Université de Bordeaux, Fondation pour la Recherche Médicale, the Conseil Régional d'Aquitaine, SIRIC-BRIO, Fondation ARC, and Institut Européen de Chimie et Biologie. C.B. was recipient of fellowships from the Minister of Higher Education, Research and Innovation (France) and the Fondation ARC (France). We thank Prof. Patricia Boya (Centro de Investigaciones Biologicas, Madrid, Spain) for kindly providing with the ATG5+/+ and ATG5−/− MEFs. We thank Prof. Benoit Viollet (Institute Cochin, Paris, France) for kindly providing with the AMPK+/+ and AMPK−/− MEFs, and the CA-AMPK plasmid.

This paper proposes a flexible modeling approach for so-called comet assay data regularly encountered in pre-clinical research. While such data consist of non-Gaussian outcomes in a multi-level hierarchical structure, traditional analyses typically completely or partly ignore this hierarchical nature by summarizing measurements within a cluster. Non-Gaussian outcomes are often modeled using exponential family models. This is true not only for binary and count data, but also for, e.g., time-to-event outcomes. Two important reasons for extending this family are: (1) the possible occurrence of overdispersion, meaning that the variability in the data may not be adequately described by the models which often exhibit a prescribed mean-variance link, and (2) the accommodation of a hierarchical structure in the data, owing to clustering in the data. The first issue is dealt with through so-called overdispersion models. Clustering is often accommodated through the inclusion of random subject-specific effects. Though not always, one conventionally assumes such random effects to be normally distributed. In the case of time-to-event data, one encounters, for example, the gamma frailty model (Duchateau and Janssen 2007). While both of these issues may occur simultaneously, models combining both are uncommon. Molenberghs et al (2010) proposed a broad class of generalized linear models accommodating overdispersion and clustering through two separate sets of random effects. Here, we use this method to model data from a comet assay with a three-level hierarchical structure. Whereas a conjugate gamma random effect is used for the overdispersion random effect, both gamma and Normal random effects are considered for the hierarchical random effect. Apart from model formulation, we place emphasis on Bayesian estimation. Our proposed method has upper hand over the traditional analysis in that it: (1) uses the appropriate distribution stipulated in the literature; (2) deals with the complete hierarchical nature; and (3) uses all information instead of summary measures. The fit of the model to the comet assay is compared against the background of more conventional model fits. Results indicate the toxicity of 1,2-Dimethylhydrazine dihydrochloride at different dose levels (low, medium, and high). ; IAP research network of the Belgian Government (Belgian Science Policy) (P6/03 ) - Fund for Scientific Research-Flanders (F.W.O.)

Resistance to anaplastic lymphoma kinase (ALK)-targeted therapy in ALK-positive non-small cell lung cancer has been reported, with the majority of acquired resistance mechanisms relying on bypass signaling. To proactively identify resistance mechanisms in ALK-positive neuroblastoma (NB), we herein employ genome-wide CRISPR activation screens of NB cell lines treated with brigatinib or ceritinib, identifying PIM1 as a putative resistance gene, whose high expression is associated with high-risk disease and poor survival. Knockdown of PIM1 sensitizes cells of differing MYCN status to ALK inhibitors, and in patient-derived xenografts of high-risk NB harboring ALK mutations, the combination of the ALK inhibitor ceritinib and PIM1 inhibitor AZD1208 shows significantly enhanced anti-tumor efficacy relative to single agents. These data confirm that PIM1 overexpression decreases sensitivity to ALK inhibitors in NB, and suggests that combined front-line inhibition of ALK and PIM1 is a viable strategy for the treatment of ALK-positive NB independent of MYCN status. ; This research is supported with funding from Children with Cancer UK (CWCUK; 16-209) awarded to S.D.T. and L.C.L., R.M.T. was supported by the CWCUK grant and L.C.L. was in receipt of a Cancer Research UK Cambridge Centre Paediatric Programme PhD studentship. N.P., L.J., O.M., I.G.F.A., L.K. and S.D.T. are supported by a European Union Horizon 2020 Marie Skłodowska–Curie Innovative Training Networks (ITN-ETN) Grant, Grant No.: 675712. N.A.P. was supported by ERASMUS+. We are grateful to AstraZeneca for providing us with AZD1208 and Inflection Biosciences for providing us with PIMi. We thank Isaia Barbieri for critical suggestions on the manuscript, BBSCR NIHR Cell phenotyping hub for flow cytometry expertise, the Bauer Core Facility at Harvard University for sequencing, and Liew Jun Mun and Stephen P. Ducray for technical assistance. Funding for the COG/ALSF Childhood Cancer Repository was provided by Alex's Lemonade Stand Foundation ; Sí

Fusion oncogenes (FOs) are common in many cancer types and are powerful drivers of tumor development. Because their expression is exclusive to cancer cells and their elimination induces cell apoptosis in FO-driven cancers, FOs are attractive therapeutic targets. However, specifically targeting the resulting chimeric products is challenging. Based on CRISPR/Cas9 technology, here we devise a simple, efficient and non-patient-specific gene-editing strategy through targeting of two introns of the genes involved in the rearrangement, allowing for robust disruption of the FO specifically in cancer cells. As a proof-of-concept of its potential, we demonstrate the efficacy of intron-based targeting of transcription factors or tyrosine kinase FOs in reducing tumor burden/mortality in in vivo models. The FO targeting approach presented here might open new horizons for the selective elimination of cancer cells. ; This work was supported by grants from the Spanish National Research and Development Plan, Instituto de Salud Carlos III, and FEDER (PI17/02303 and DTS19/00111 to S.R-P.); AEI/MICIU EXPLORA Project BIO2017-91272-EXP and CaixaImpulse (CI18-00017;FuGe) to S.R-P. RT-R. is supported by a postdoctoral fellowship from the Asociacion Espanola Contra el Cancer (AECC). P.M. is supported by the European Research Council (CoG-2014-646903 and PoC-2018-811220), the Spanish Ministry of Science, Innovation and Universities (SAF2016), and the Catalunya Government (SGR330 and PERIS 2017). J.C.S. is supported by the Spanish Ministry of Science, Innovation and Universities (SAF2017-84248-P) and the Spanish Cell Therapy cooperative research network (TERCEL)(RD16/0011/0011). C.B. is supported by the AECC, Beca FERO, and the ISCIII/FEDER (PI17/01028). P.M. also acknowledges the financial support from the Obra Social La Caixa-Fundaci Josep Carreras. P.M. is an investigator of the Spanish Cell Therapy cooperative research network (TERCEL). A.M.C. acknowledges funding from ISCIII-FEDER (CP13/00189) and Xarxa de Bancs de Tumors de ...

Es comunicación (formato panel) a congreso internacional ; In this work we developed a new synthetic strategy towards the solomonamides. a novel class of cyclopeptides of marine origin. The described synthetic approach utilized an olefin metathesis reaction to form the [15]-membered ring contained in these natural products. During the synthetic process, a diverse set of analogues was generated and we evaluated their potential antitumor activity in vitro. For this purpose we performed in vitro proliferation assays, determining the IC50 values of the compounds in a panel of tumor cell lines. In addition, we evaluated the possible antiangiogenic effects of these solomonamide analogues by using in vitro endothelial cell differentiation assays. Our results showed that the potential antitumor and antiangiogenic activity of the studied analogues depended on their chemical structure, suggesting that the presence of specific functional groups could be responsible of their biological activity. Further studies are needed to understand the basis of the observed activities in endothelial and tumor cells. ; Our experimental work is supported by grants BIO2014-56092-R (MINECO and FEDER) and P12-CTS-1507 (Andalusian Government and FEDER) and funds from group BIO-267 (Andalusian Government). The "CIBER de Enfermedades Raras" is an initiative from the ISCIII (Spain). This communicaction has the support of a travel grant "Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech"

Chengyuan Qian, Mengxia Li, Jiangdong Sui, Tao Ren, Zheng Li, Liang Zhang, Liwei Zhou, Yi Cheng, Dong WangCancer Center, Daping Hospital and Research Institute of Surgery, Third Military Medical University, Chongqing, People's Republic of ChinaAbstract: The human apurinic/apyrimidinic endonuclease 1/redox enhancing factor-1 (APE1/Ref-1), an essential multifunctional protein involved in the repair of oxidative deoxyribonucleic acid (DNA) damage and transcriptional regulation, is often overexpressed in tumor tissues and cancer cells. Moreover, APE1/Ref-1 (APE1) overexpression has been linked to chemoresistance in human tumors. Thus, inhibiting APE1 function in cancer cells is considered a promising strategy to overcome resistance to therapeutic agents. Gossypol is a Bcl-2 homology 3 (BH3)-mimetic agent and is able to bind to the BH3 domain of B-cell lymphoma 2 (Bcl-2) family members. Other studies demonstrated that Bcl-2 directly interacted with APE1 via its BH domains. Using apurinic/apyrimidinic (AP) endonuclease assays, we found that gossypol inhibits the repair activity of APE1. Electrophoretic mobility shift assays and dual luciferase assays showed that gossypol could also inhibit the redox function of APE1. Using dual polarization interferometry technology, we show that gossypol can directly interact with APE1. Furthermore, addition of gossypol, in conjunction with APE1 overexpression, leads to cancer cell death. The addition of gossypol also enhances the cell killing effect of the laboratory alkylating agent methyl methanesulfonate and the clinical agent cisplatin (DDP). Administration of gossypol significantly inhibited the growth of xenografts. Furthermore, the combined treatment of gossypol and DDP resulted in a statistically higher antitumor activity compared with DDP alone in vivo. In conclusion, we have demonstrated that gossypol effectively inhibits the repair and redox activity of APE1 through a direct interaction.Keywords: cancer, oxidative DNA damage, BH3-mimetic

ERDF Funds from the EuropeanUnion; INNPACTO-ONCOPAN [IPT-010000-2010-31]; Ministry of Science and Innovation, SpainSpanish Government [FISS-09-PS09/01911]; FICYT, Axe 1 of the 2007-2013 ERDF Operational Framework Program of the Principality of Asturias, Spain [FC-11-PC10-23]; Progenika Biopharma, S.A.; Oncomatryx, S.L. Derio, Spain