The TGFβ pathway stimulates ovarian cancer cell proliferation by increasing IGF1R levels

In a search for new therapeutic targets for treating epithelial ovarian cancer, we analyzed the Transforming Growth Factor Beta (TGFβ) signaling pathway in these tumors. Using a TMA with patient samples we found high Smad2 phosphorylation in ovarian cancer tumoral cells, independently of tumor subtype (high-grade serous or endometrioid). To evaluate the impact of TGFβ receptor inhibition on tumoral growth, we used different models of human ovarian cancer orthotopically grown in nude mice (OVAs). Treatment with a TGFβRI&II dual inhibitor, LY2109761, caused a significant reduction in tumor size in all these models, affecting cell proliferation rate. We identified Insulin Growth Factor (IGF)1 receptor as the signal positively regulated by TGFβ implicated in ovarian tumor cell proliferation. Inhibition of IGF1R activity by treatment with a blocker antibody (IMC-A12) or with a tyrosine kinase inhibitor (linsitinib) inhibited ovarian tumoral growth in vivo. When IGF1R levels were decreased by shRNA treatment, LY2109761 lost its capacity to block tumoral ovarian cell proliferation. At the molecular level TGFβ induced mRNA IGF1R levels. Overall, our results suggest an important role for the TGFβ signaling pathway in ovarian tumor cell growth through the control of IGF1R signaling pathway. Moreover, it identifies anti-TGFβ inhibitors as being of potential use in new therapies for ovarian cancer patients as an alternative to IGF1R inhibition

TGFβ controls ovarian cancer cell proliferation

There have been no major improvements in the overall survival of ovarian cancer patients in recent decades. Even though more accurate surgery and more effective treatments are available, the mortality rate remains high. Given the differences in origin and the heterogeneity of these tumors, research to elucidate the signaling pathways involved is required. The Transforming Growth Factor (TGFβ) family controls different cellular responses in development and cell homeostasis. Disruption of TGFβ signaling has been implicated in many cancers, including ovarian cancer. This article considers the involvement of TGFβ in ovarian cancer progression, and reviews the various mechanisms that enable the TGFβ signaling pathway to control ovarian cancer cell proliferation. These mechanistic explanations support the therapeutic use of TGFβ inhibitors in ovarian cancer, which are currently in the early phases of development

A role for CXCR4 in peritoneal and hematogenous ovarian cancer dissemination

Epithelial ovarian cancer is characterized by a low recovery rate because the disease is typically diagnosed at an advanced stage, by which time most patients (80%) already exhibit disseminated neoplasia. The cytokine receptor CXCR4 has been implicated in the development of metastasis in various tumor types. Using a patient-derived tissue macroarray and mRNA expression analysis, we observed high CXCR4 levels in high-grade serous epithelial ovarian carcinomas, the most metastatic tumor, compared with those in endometrioid carcinomas. CXCR4 inhibition by treatment with the CXCR4 antagonist AMD3100 or by expression of shRNA anti-CXCR4 similarly inhibited angiogenesis in several models of ovarian carcinomas orthotopically grown in nude mice, but the effect on tumor growth was correlated with the levels of CXCR4 expression. Moreover, CXCR4 inhibition completely blocked dissemination and metastasis. This effect was associated with reduced levels of active Src, active ERKs, the inhibition of EMT transition, and block of hematogenous ovarian cancer dissemination decreasing circulating human tumoral cells (CTC). In tumors, CXCR4-expressing cells also had more mesenchymal characteristics. In conclusion, our results indicate that CXCR4 expression confers a proinvasive phenotype to ovarian carcinoma cells. Thus, anti-CXCR4 therapy is a possible agent for a complementary treatment of advanced disseminated epithelial high-grade serous ovarian cancer patients.This study was supported by research grants from the Spanish Ministerio de Economía y Competitividad (SAF2013-46063R), The Spanish Institute of Health Carlos III (ISCIII) and the European Regional Development Fund (ERDF) under the Integrated Project of Excellence no. PIE13/00022 (ONCOPROFILE), and the Generalitat de Catalunya (2014SGR364) to F. Vinals. Work supported by the Xarxa de Bancs de Tumors de Catalunya sponsored by Pla Director d'Oncología de Catalunya (XBTC), IDIBELL and PLATAFORMA BIOBANCOSPT13/0010/0013 and for the MD Anderson Foundation Biobank (B.0000745, ISCIII National Biobank Record). Grants from the AECC (Grupos Estables de Investigacion 2011-AECC-GCB 110333 REVE), the Instituto de Salud Carlos III (ISCIII), FEDER (PI16/00134), and CIBERONC (CB16/12/00295) to G. Moreno-Bueno. E. Alsina-Sanchís is a recipient of a predoctoral fellowship from the Ministerio de Economía y Competitividad.Peer reviewe

Tumors defective in homologous recombination rely on oxidative metabolism: relevance to treatments with PARP inhibitors

Mitochondrial metabolism and the generation of reactive oxygen species (ROS) contribute to the acquisition of DNA mutations and genomic instability in cancer. How genomic instability influences the metabolic capacity of cancer cells is nevertheless poorly understood. Here, we show that homologous recombination-defective (HRD) cancers rely on oxidative metabolism to supply NAD+ and ATP for poly(ADP-ribose) polymerase (PARP)-dependent DNA repair mechanisms. Studies in breast and ovarian cancer HRD models depict a metabolic shift that includes enhanced expression of the oxidative phosphorylation (OXPHOS) pathway and its key components and a decline in the glycolytic Warburg phenotype. Hence, HRD cells are more sensitive to metformin and NAD+ concentration changes. On the other hand, shifting from an OXPHOS to a highly glycolytic metabolism interferes with the sensitivity to PARP inhibitors (PARPi) in these HRD cells. This feature is associated with a weak response to PARP inhibition in patient-derived xenografts, emerging as a new mechanism to determine PARPi sensitivity. This study shows a mechanistic link between two major cancer hallmarks, which in turn suggests novel possibilities for specifically treating HRD cancers with OXPHOS inhibitors

Defectos en la reparación homóloga producen un aumento del metabolismo oxidativo en cáncer de ovario: relevancia para los tratamientos con inhibidores de PARP

[spa] Hipótesis: ¿El daño crónico en el ADN o bloqueo de la HR crónico produce un shift o una selección de células que han cambiado su metabolismo para poder sobrevivir a la situación? Objetivos: El principal objetivo de esta tesis doctoral ha sido estudiar la correlación entre los defectos de reparación en la recombinación homóloga o daño crónico en el ADN y la adaptación metabólica que se lleva a cabo para poder sobrevivir en esa situación en el cáncer de ovario seroso de alto grado. Como objetivos concretos de la tesis tenemos: A) Generación y caracterización de modelos que padezcan daño crónico en el ADN o sufran defectos en la reparación por recombinación homóloga. B) Estudiar los mecanismos de adaptación metabólica de estos modelos celulares al daño crónico y los fallos en la recombinación homologa C) Ver el papel que pueden jugar inhibidores de la cadena respiratoria como posibles tratamientos a tumores de estas características y las interacciones con otros tratamientos que se utilizan actualmente

Tumors defective in homologous recombination rely on oxidative metabolism: relevance to treatments with PARP inhibitors

Inhibidors de la PARP; Metabolisme del càncer; MetforminaInhibidores de PARP, Metabolismo del cáncer; MetforminaPARP inhibitors; Cancer metabolism; MetforminMitochondrial metabolism and the generation of reactive oxygen species (ROS) contribute to the acquisition of DNA mutations and genomic instability in cancer. How genomic instability influences the metabolic capacity of cancer cells is nevertheless poorly understood. Here, we show that homologous recombination-defective (HRD) cancers rely on oxidative metabolism to supply NAD+ and ATP for poly(ADP-ribose) polymerase (PARP)-dependent DNA repair mechanisms. Studies in breast and ovarian cancer HRD models depict a metabolic shift that includes enhanced expression of the oxidative phosphorylation (OXPHOS) pathway and its key components and a decline in the glycolytic Warburg phenotype. Hence, HRD cells are more sensitive to metformin and NAD+ concentration changes. On the other hand, shifting from an OXPHOS to a highly glycolytic metabolism interferes with the sensitivity to PARP inhibitors (PARPi) in these HRD cells. This feature is associated with a weak response to PARP inhibition in patient-derived xenografts, emerging as a new mechanism to determine PARPi sensitivity. This study shows a mechanistic link between two major cancer hallmarks, which in turn suggests novel possibilities for specifically treating HRD cancers with OXPHOS inhibitors.This study has been funded by the Ministerio de Ciencia, Innovación y Universidades, which is part of the Agencia Estatal de Investigación (AEI), through the project SAF2017-85869-R (cofunded by the European Regional Development Fund (ERDF), a way to build Europe) to FV and BFU2015-66030-R to JCP; by the FIS PI15/00854 and FIS PI16/01898 (Instituto Carlos III, cofunded by FEDER funds/European Regional Development Fund (ERDF), a way to build Europe) to MAP and AVillanueva and with the support of the Secretariat for Universities and Research of the Department of Business and Knowledge of the Government of Catalonia (2017SGR449) to FV. We thank the CERCA Program/Generalitat de Catalunya for their institutional support. We particularly wish to acknowledge the collaboration of the patients and the IDIBGI Biobank (Biobanc IDIBGI, B.0000872), which is part of the Spanish National Biobank Network and the Xarxa de Bancs de Tumors de Catalunya (XBTC), financed by the Pla Director d'Oncologia de Catalunya, Spain. We thank Cristina Saura (Breast Cancer & Melanoma Group) and people from the Experimental Therapeutics Group at VHIO and Sara González (Unitat de Diagnòstic Molecular, ICO-Duran i Reynals). We thank H. Simon, R. Bartrons, and A. Manzano (Universitat de Barcelona) and A. Vaquero (IDIBELL) for reagents

Tumors defective in homologous recombination rely on oxidative metabolism: relevance to treatments with PARP inhibitors.

Mitochondrial metabolism and the generation of reactive oxygen species (ROS) contribute to the acquisition of DNA mutations and genomic instability in cancer. How genomic instability influences the metabolic capacity of cancer cells is nevertheless poorly understood. Here, we show that homologous recombination-defective (HRD) cancers rely on oxidative metabolism to supply NAD+ and ATP for poly(ADP-ribose) polymerase (PARP)-dependent DNA repair mechanisms. Studies in breast and ovarian cancer HRD models depict a metabolic shift that includes enhanced expression of the oxidative phosphorylation (OXPHOS) pathway and its key components and a decline in the glycolytic Warburg phenotype. Hence, HRD cells are more sensitive to metformin and NAD+ concentration changes. On the other hand, shifting from an OXPHOS to a highly glycolytic metabolism interferes with the sensitivity to PARP inhibitors (PARPi) in these HRD cells. This feature is associated with a weak response to PARP inhibition in patient-derived xenografts, emerging as a new mechanism to determine PARPi sensitivity. This study shows a mechanistic link between two major cancer hallmarks, which in turn suggests novel possibilities for specifically treating HRD cancers with OXPHOS inhibitors