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

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

Role of TGFβ family members on physiological angiogenesis and ovarian cancer

[eng] Role of TGFβ in physiological angiogenesis and ovarian cancer Transforming Growth Factor Beta (TGFβ) is a signalling pathway involved in a wide range of cellular processes such as proliferation, differentiation, angiogenesis, migration and homeostasis. In addition, it has been broadly related with pathological situations like cancer or other diseases. In this thesis we have been focused on two of its receptors; the TβRI called ALK5, ubiquitously expressed, and ALK1, an endothelial cell-restricted receptor. In the first part of this work we have studied the role of ALK1 in angiogenesis. Loss of function mutations in ALK1 cause a subtype of hereditary haemorrhagic telangiectasias (HHTs) characterized by vasculature malformations. Currently, there is no suitable treatment to cure these patients. To study the ALK1 role in vascular development, we have used the retina mouse model and seeking to find a treatment for these patients, we have used a mouse model for HHTs. This mouse model has a heterozygous alteration in ALK1, as in homozygosis die at +/- mice resulted in abnormal endothelial cell proliferation mid-gestion. The alteration on ALK1 and increased retinal vessel width without affecting pericyte coverage, migration or elongation of the ECs. We have shown that genetic and pharmacological inhibition of PI3K signalling +/- abolished the increase in vessel width in ALK1 retinas and normalized vasculature. Overall, our results suggest the potential for using PI3K inhibitors as new therapeutic agents for treating HHTs. In the second part of this work we have searched for new therapeutic targets for treating epithelial ovarian cancer. Firstly, we analysed the TGFβ signalling pathway in these tumours. Using a Tissue Micro Array (TMA) with patient samples we found high Smad2 phosphorylation, a read-out of ALK5 activation, in epithelial ovarian cancer tumoral cells, independently of tumour subtype (high-grade serous or endometrioid). To evaluate the impact of TGFβ receptor inhibition on tumoral growth, we used different models of human epithelial ovarian cancer orthotopically grown in nude mice (OVAs); two high-grade serous carcinoma and one endometrioid carcinoma. We have confirmed that the histological properties and the levels of phosphoSmad2 expression pattern were maintained on the ovarian tumour mouse models compared to its human primary tumours samples. Treatment with a TGFβRI&II dual inhibitor, LY2109761, caused a significant reduction in tumour size in all these models, affecting cell proliferation rate. On the contrary, TGFβ inhibition did not affect ovarian tumour cell capacity to disseminate in our models. We identified Insulin Growth Factor (IGF)1 receptor as the signal positively regulated by TGFβ implicated in ovarian tumour cell proliferation. We have demonstrated that our TMA samples had high IGF1R protein levels and that phosphoSmad2 and IGF1R protein levels significantly positively correlated. 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. At the molecular level TGFβ signalling positively controls IGF1R levels by two mechanisms. Induction of mRNA IGF1R levels in some cell lines or tumour samples, whereas a change on IGF1R protein localization was observed in others. In fact, TGFβ inhibition decreased IGF1R protein levels by controlling its stability; increasing IGF1R internalization and degradation through the lysosome. When IGF1R levels were decreased by shRNA treatment, ovarian cancer cell lines grew less and LY2109761 lost its capacity to block tumoral ovarian cell proliferation. Overall, our results suggest an important role for the TGFβ signalling pathway in ovarian tumour cell growth through the control of IGF1R signalling 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, being used in clinical trials.[cat] Aquest treball estudia el paper de la família del Factor de Creixement Transformant (TGFβ) en el càncer d’ovari i en una altra patologia, la telangectàsia hemorràgica hereditària (HHT). Mutacions de pèrdua de funció del receptor ALK1 causen un subtipus de HHT caracteritzat per malformacions vasculars. Per analitzar el rol d'ALK1 en el desenvolupament vascular, hem utilitzat un model animal d'HHT. Les alteracions obtingudes han estat una proliferació anormal de les cèl.lules endotelials i un augment de l'amplitud dels vasos de la retina dels ratolins ALK1+/-. Hem demostrat que una inhibició genètica o farmacològica de la via de senyalització de PI3K aboleix l'augment de l'amplitud de vasos i la vasculatura queda normalitzada, suggerint el potencial ús dels inhibidors de PI3K com a nous agents terapèutics pel tractament d'aquests pacients. En la segona part d'aquest treball, hem buscat nous agents terapèutics pel tractament del càncer d'ovari. Utilitzant mostres de pacients, hem observat alts nivells de Smad2 fosforilat en les cèl.lules tumorals de càncer d'ovari, independentment del tipus de tumor. El tractament amb l'inhibidor de TGFβRI&II, LY2109761, en els models ortotòpics de càncer d'ovari causa una reducció significativa de la mida tumoral, afectant la proliferació cellular. Hem identificat el receptor del Factor de Creixement de la Insulina (IGF)1 com la via implicada en la proliferació de les cèl.lules tumorals d'ovari, la qual és regulada positivament per TGFβ. La inhibició de l'activitat d'IGF1R inhibeix el creixement del tumor d'ovari in vivo. A nivell molecular, TGFβ controla els nivells de mRNA d'IGF1R i també la seva internalització i degradació proteica a través del lisosoma. Quan els nivells d'IGF1R són disminuïts per la utilització d'un shRNA, LY2109761 perd la capacitat de bloquejar la proliferació de la cèl.lula tumoral d'ovari. Aquests resultats postulen que TGFβ. té un paper important en el creixement cellular del tumor d'ovari a través del control de la senyalització d'IGF1R. A més, identifica els inhibidors contra TGFβ com a noves teràpies pels pacients de càncer d'ovari com una alternativa als inhibidors d'IGF1R

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

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

ALK1 loss results in vascular hyperplasia in mice and humans through PI3K activation

Objective: ALK1 (activin-receptor like kinase 1) is an endothelial cell-restricted receptor with high affinity for BMP (bone morphogenetic protein) 9 TGF-[beta] (transforming growth factor-[beta]) family member. Loss-of-function mutations in ALK1 cause a subtype of hereditary hemorrhagic telangiectasia-a rare disease characterized by vasculature malformations. Therapeutic strategies are aimed at reducing potential complications because of vascular malformations, but currently, there is no curative treatment for hereditary hemorrhagic telangiectasia. Approach and results: in this work, we report that a reduction in ALK1 gene dosage (heterozygous ALK1+/- mice) results in enhanced retinal endothelial cell proliferation and vascular hyperplasia at the sprouting front. We found that BMP9/ALK1 represses VEGF (vascular endothelial growth factor)-mediated PI3K (phosphatidylinositol 3-kinase) by promoting the activity of the PTEN (phosphatase and tensin homolog). Consequently, loss of ALK1 function in endothelial cells results in increased activity of the PI3K pathway. These results were confirmed in cutaneous telangiectasia biopsies of patients with hereditary hemorrhagic telangiectasia 2, in which we also detected an increase in endothelial cell proliferation linked to an increase on the PI3K pathway. In mice, genetic and pharmacological inhibition of PI3K is sufficient to abolish the vascular hyperplasia of ALK1+/- retinas and in turn normalize the vasculature. Conclusions: overall, our results indicate that the BMP9/ALK1 hub critically mediates vascular quiescence by limiting PI3K signaling and suggest that PI3K inhibitors could be used as novel therapeutic agents to treat hereditary hemorrhagic telangiectasia