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Supplementary Figure 1. Expression of CXCR4 by immunofluorescence and of mouse Cxcr4 and human CXCR7 by RT-PCR; Supplementary Figure 2. Decrease in number of CXCR4-positive cells arising from AMD3100 treatment; Supplementary Figure 3. Absence of effect of AMD3100 on fibrosis, necrosis and proliferation; Supplementary Figure 4. Inhibition of angiogenesis by AMD3100; Supplementary Figure 5. Cytometric analysis of CTCs in blood of OVA17 implanted animals; Supplementary Figure 6. Cytokeratin 19 mRNA analysis in blood from ovarian carcinoma patients; Supplementary Figure 7. CXCR4 immunostaining in SKOV-3 tumors; Supplementary Figure 8. Absence of effect of shCXCR4 expression in SKOV-3 cells proliferation and viability, but decrease of angiogenesis in tumors; Supplementary Figure 9. Cytometric analysis of CTCs in blood of SKOV-3-sh control and SKOV-3-shCXCR4 863 inoculated animals; Supplementary Figure 10. CXCR4 inhibition by shRNA expression blocks Src and ERKs activation; Supplementary Figure 11. Cytometric analysis of GFP and CXCR4 expression in cells isolated from SKOV-3 xenografts; Supplementary Figure 12. CXCR4 and E-cadherin expression in consecutive sections of OVA17 tumors

Analysis of GDC-0941 effects on cell proliferation ; Supplemental Figure 2 Legend

Purpose:FGFR1 amplification (FGFR1amp) is recurrent in metastatic breast cancer (MBC) and is associated with resistance to endocrine therapy and CDK4/6 inhibitors (CDK4/6is). Multi-tyrosine kinase inhibitors (MTKIs) and selective pan-FGFR inhibitors (FGFRis) are being developed for FGFR1amp breast cancer. High-level FGFR amplification and protein expression by IHC have identified breast cancer responders to FGFRis or MTKIs, respectively.Experimental Design:Here, we used preclinical models and patient samples to identify predictive biomarkers to these drugs. We evaluated the antitumor activity of an FGFRi and an MTKI in a collection of 17 breast cancer patient–derived xenografts (PDXs) harboring amplification in FGFR1/2/3/4 and in 10 patients receiving either an FGFRi/MTKI. mRNA levels were measured on FFPE tumor samples using two commercial strategies. Proliferation and angiogenesis were evaluated by detecting Ki-67 and CD31 in viable areas by immunofluorescence.Results:High FGFR1–4 mRNA levels but not copy-number alteration (CNA) is associated with FGFRi response. Treatment with MTKIs showed higher response rates than with FGFRis (86% vs. 53%), regardless of the FGFR1–4 mRNA levels. FGFR-addicted PDXs exhibited an antiproliferative response to either FGFRis or MTKIs, and PDXs exclusively sensitive to MTKI exhibited an additional antiangiogenic response. Consistently, the clinical benefit of MTKIs was not associated with high FGFR1–4 mRNA levels and was observed in patients previously treated with antiangiogenic drugs.Conclusions:Tailored therapy with FGFRis in molecularly selected MBC based on high FGFR1–4 mRNA levels warrants prospective validation in patients with CDK4/6i-resistant luminal breast cancer and in patients with TNBC without targeted therapeutic options.

Supplementary Table S2 HTG OBP panel raw data

Assessment of cell proliferation upon inhibition of p110α ; Supplemental Figure 5 Legend

Supplementary Figure Legends

Survival curves upon genetic inactivation of individual p110s ; Supplemental Figure 3 Legend

Supplementary Figure 5. Relative expression levels of lucitanib-specific RTK targets and ligands in PDX and patient tumors. A) mRNA expression levels of 2544 genes detected by HTG in Pt325 samples (Pre-tt versus On-tt). Highlighted are some differentially expressed genes between both samples, including FGFR1. Data is log-2 transformed. B) and C) Relative mRNA levels of lucitanib-specific RTK targets or cognate ligands in PDX and patient tumors from the MTKI/FGFRi-treated patient cohort from Figure 3D, respectively.

Index of all Supplementary Data

Supplementary Materials and Methods

Analysis of PTEN expression in PanNETs ; Supplemental Figure 1 Legend

This file contains information about protein immunoblotting, histopathological analysis, and cell biological assays in cultured cells.

Supplementary figures on vessel phenotype, tumor effects, combo treatment, macrophage phenotype and effects, and human validation.

Expression of some angiogenesis related genes in response to anti-Sema4D and anti-VEGFR2 treatment

One of the main consequences of inhibition of neovessel growth and vessel pruning produced by angiogenesis inhibitors is increased intratumor hypoxia. Growing evidence indicates that tumor cells escape from this hypoxic environment to better nourished locations, presenting hypoxia as a positive stimulus for invasion. In particular, anti-VEGF/R therapies produce hypoxia-induced invasion and metastasis in a spontaneous mouse model of pancreatic neuroendocrine cancer (PanNET), RIP1-Tag2. Here, a novel vascular-targeting agent targeting semaphorin 4D (Sema4D) demonstrated impaired tumor growth and extended survival in the RIP1-Tag2 model. Surprisingly, although there was no induction of intratumor hypoxia by anti-Sema4D therapy, the increase in local invasion and distant metastases was comparable with the one produced by VEGFR inhibition. Mechanistically, the antitumor effect was due to an alteration in vascular function by modification of pericyte coverage involving platelet-derived growth factor B. On the other hand, the aggressive phenotype involved a macrophage-derived Sema4D signaling engagement, which induced their recruitment to the tumor invasive fronts and secretion of stromal cell–derived factor 1 (SDF1) that triggered tumor cell invasive behavior via CXCR4. A comprehensive clinical validation of the targets in different stages of PanNETs demonstrated the implication of both Sema4D and CXCR4 in tumor progression. Taken together, we demonstrate beneficial antitumor and prosurvival effects of anti-Sema4D antibody but also unravel a novel mechanism of tumor aggressivity. This mechanism implicates recruitment of Sema4D-positive macrophages to invasive fronts and their secretion of proinvasive molecules that ultimately induce local tumor invasion and distant metastasis in PanNETs.Significance:An anti-semaphorin-4D vascular targeting agent demonstrates antitumor and prosurvival effects but also unravels a novel promalignant effect involving macrophage-derived SDF1 that promotes tumor invasion and metastasis, both in animal models and patients.See related commentary by Tamagnone and Franzolin, p. 5146

Analysis of angiogenic islet upon genetic inactivation of p110α, p110β and p110Î' ; Supplemental Figure 4 Legend

Ranked list of proteins present in anti-Sema4D treated macrophage conditioned media obtained in the GSEA analysis of the proteomic data

Purpose: Mutations in the PI3K pathway occur in 16% of patients with pancreatic neuroendocrine tumors (PanNETs), which suggests that these tumors are an exciting setting for PI3K/AKT/mTOR pharmacologic intervention. Everolimus, an mTOR inhibitor, is being used to treat patients with advanced PanNETs. However, resistance to mTOR-targeted therapy is emerging partially due to the loss of mTOR-dependent feedback inhibition of AKT. In contrast, the response to PI3K inhibitors in PanNETs is unknown.Experimental Design: In the current study, we assessed the frequency of PI3K pathway activation in human PanNETs and in RIP1-Tag2 mice, a preclinical tumor model of PanNETs, and we investigated the therapeutic efficacy of inhibiting PI3K in RIP1-Tag2 mice using a combination of pan (GDC-0941) and p110α-selective (GDC-0326) inhibitors and isoform-specific PI3K kinase-dead–mutant mice.Results: Human and mouse PanNETs showed enhanced pAKT, pPRAS40, and pS6 positivity compared with normal tissue. Although treatment of RIP1-Tag2 mice with GDC-0941 led to reduced tumor growth with no impact on tumor vessels, the selective inactivation of the p110α PI3K isoform, either genetically or pharmacologically, reduced tumor growth as well as vascular area. Furthermore, GDC-0326 reduced the incidence of liver and lymph node metastasis compared with vehicle-treated mice. We also demonstrated that tumor and stromal cells are implicated in the antitumor activity of GDC-0326 in RIP1-Tag2 tumors.Conclusions: Our data provide a rationale for p110α-selective intervention in PanNETs and unravel a new function of this kinase in cancer biology through its role in promoting metastasis. Clin Cancer Res; 22(23); 5805–17. ©2016 AACR.

List of cytokines modified in response to anti-Sema4D treatment (Cytokine array)

Reciprocal interactions between endothelial cells (ECs) and adipocytes are fundamental to maintain white adipose tissue (WAT) homeostasis, as illustrated by the activation of angiogenesis upon WAT expansion, a process that is impaired in obesity. However, the molecular mechanisms underlying the crosstalk between ECs and adipocytes remain poorly understood. Here, we show that local production of polyamines in ECs stimulates adipocyte lipolysis and regulates WAT homeostasis in mice. We promote enhanced cell-autonomous angiogenesis by deleting Pten in the murine endothelium. Endothelial Pten loss leads to a WAT-selective phenotype, characterized by reduced body weight and adiposity in pathophysiological conditions. This phenotype stems from enhanced fatty acid β-oxidation in ECs concomitant with a paracrine lipolytic action on adipocytes, accounting for reduced adiposity. Combined analysis of murine models, isolated ECs and human specimens reveals that WAT lipolysis is mediated by mTORC1-dependent production of polyamines by ECs. Our results indicate that angiocrine metabolic signals are important for WAT homeostasis and organismal metabolism. We thank members of the Endothelial Pathobiology and Microenvironment Group for helpful discussions. We thank the CERCA Program/Generalitat de Catalunya and the Josep Carreras Foundation for institutional support. The research leading to these results has received funding from la Fundación BBVA (Ayuda Fundacion BBVA a Equipos de Investigación Científica 2019, PR19BIOMET0061) and from SAF2017-82072-ERC from Ministerio de Ciencia, Innovación y Universidades (MCIU) (Spain). The laboratory of M.G. is also supported by the research grants SAF2017-89116R-P (FEDER/EU) co-funded by European Regional Developmental Fund (ERDF), a Way to Build Europe and PID2020-116184RB-I00 from MCEI; by the Catalan Government through the project 2017-SGR; PTEN Research Foundation (BRR-17-001); La Caixa Foundation (HR19-00120 and HR21-00046); by la Asociación Española contra el Cancer-Grupos Traslacionales (GCTRA18006CARR, also to A.C.); European Foundation for the Study of Diabetes/Lilly research grant, also to M.C.); and by the People Programme (Marie Curie Actions; grant agreement 317250) of the European Union’s Seventh Framework Programme FP7/2007-2013 and the Marie Skłodowska-Curie (grant agreement 675392) of the European Union’s Horizon 2020 research. The laboratory of A.C. is supported by the Basque Department of Industry, Tourism and Trade (Elkartek) and the department of education (IKERTALDE IT1106-16), the MCIU (PID2019-108787RB-I00 (FEDER/ EU); Severo Ochoa Excellence Accreditation SEV-2016-0644; Excellence Networks SAF2016-81975-REDT), La Caixa Foundation (ID 100010434), under the agreement LCF/PR/HR17, the Vencer el Cancer foundation and the European Research Council (ERC) (consolidator grant 819242). CIBERONC was co-funded with FEDER funds and funded by Instituto de Salud Carlos III (ISCIII). The laboratory of M.C. is supported by the ERC under the European Union’s Horizon 2020 research and innovation programme (grant agreement 725004) and CERCA Programme/Generalitat de Catalunya (M.C.). The laboratory of D.S. is supported by research grants from MINECO (SAF2017- 83813-C3-1-R, also to L.H., cofounded by the ERDF), CIBEROBN (CB06/03/0001), Government of Catalonia (2017SGR278) and Fundació La Marató de TV3 (201627- 30). The laboratory of R.N. is supported by FEDER/Ministerio de Ciencia, Innovación y Universidades-Agencia Estatal de Investigación (RTI2018-099413-B-I00 and and RED2018-102379-T), Xunta de Galicia (2016-PG057 and 2020-PG015), ERC under the European Union’s Horizon 2020 research and innovation programme (grant agreement 810331), Fundación BBVA, Fundacion Atresmedia and CIBEROBN, which is an initiative of the ISCIII of Spain, which is supported by FEDER funds. The laboratory of J.A.V. is supported by research grants from MICINN (RTI2018-099250-B100) and by La Caixa Foundation (ID 100010434, LCF/PR/HR17/52150009). P.M.G.-R. is supported by ISCIII grant PI15/00701 cofinanced by the ERDF, A Way to Build Europe. Personal support was from Marie Curie ITN Actions (E.M.), Juan de la Cierva (IJCI-2015-23455, P.V.), CONICYT fellowship from Chile (S.Z.), Vetenskapsradet (Swedish Research Council, 2018-06591, L.G.) and NCI K99/R00 Pathway to Independence Award (K99CA245122, P. Castel). Sí

Purpose:FGFR1 amplification (FGFR1amp) is recurrent in metastatic breast cancer (MBC) and is associated with resistance to endocrine therapy and CDK4/6 inhibitors (CDK4/6is). Multi-tyrosine kinase inhibitors (MTKIs) and selective pan-FGFR inhibitors (FGFRis) are being developed for FGFR1amp breast cancer. High-level FGFR amplification and protein expression by IHC have identified breast cancer responders to FGFRis or MTKIs, respectively.Experimental Design:Here, we used preclinical models and patient samples to identify predictive biomarkers to these drugs. We evaluated the antitumor activity of an FGFRi and an MTKI in a collection of 17 breast cancer patient–derived xenografts (PDXs) harboring amplification in FGFR1/2/3/4 and in 10 patients receiving either an FGFRi/MTKI. mRNA levels were measured on FFPE tumor samples using two commercial strategies. Proliferation and angiogenesis were evaluated by detecting Ki-67 and CD31 in viable areas by immunofluorescence.Results:High FGFR1–4 mRNA levels but not copy-number alteration (CNA) is associated with FGFRi response. Treatment with MTKIs showed higher response rates than with FGFRis (86% vs. 53%), regardless of the FGFR1–4 mRNA levels. FGFR-addicted PDXs exhibited an antiproliferative response to either FGFRis or MTKIs, and PDXs exclusively sensitive to MTKI exhibited an additional antiangiogenic response. Consistently, the clinical benefit of MTKIs was not associated with high FGFR1–4 mRNA levels and was observed in patients previously treated with antiangiogenic drugs.Conclusions:Tailored therapy with FGFRis in molecularly selected MBC based on high FGFR1–4 mRNA levels warrants prospective validation in patients with CDK4/6i-resistant luminal breast cancer and in patients with TNBC without targeted therapeutic options.

Scientific community have gained lots of new insights in the genetic and biochemical background of different conditions, rare diseases included, settling the basis for preclinical models that are helping to identify new biomarkers and therapeutic targets. Translational Medicine (TM) is an interdisciplinary area of biomedicine with an essential role in bench-to-bedside transition enhancement, generating a circular flow of knowledge transference between research environment and clinical setting, always centered in patient needs. Here, we present different tools used in TM and an overview of what is being done related to hereditary hemorrhagic telangiectasia (HHT), as a disease's model. This work is focused on how this combination of basic and clinical research impacts in HHT patient's daily clinical management and also looking into the future. Further randomized clinical trials with HHT patients should assess the findings of this bench-to-bedside transition. The benefits of this basic and clinical research combination, may not only be important for HHT patients but for patients with other vascular diseases sharing angiogenic disturbances.

Oncogenic mutations in PIK3CA, encoding p110α-PI3K, are a common cause of venous and lymphatic malformations. Vessel type–specific disease pathogenesis is poorly understood, hampering development of efficient therapies. Here, we reveal a new immune-interacting subtype of Ptx3-positive dermal lymphatic capillary endothelial cells (iLECs) that recruit pro-lymphangiogenic macrophages to promote progressive lymphatic overgrowth. Mouse model of Pik3caH1047R-driven vascular malformations showed that proliferation was induced in both venous and lymphatic ECs but sustained selectively in LECs of advanced lesions. Single-cell transcriptomics identified the iLEC population, residing at lymphatic capillary terminals of normal vasculature, that was expanded in Pik3caH1047R mice. Expression of pro-inflammatory genes, including monocyte/macrophage chemokine Ccl2, in Pik3caH1047R-iLECs was associated with recruitment of VEGF-C–producing macrophages. Macrophage depletion, CCL2 blockade, or anti-inflammatory COX-2 inhibition limited Pik3caH1047R-driven lymphangiogenesis. Thus, targeting the paracrine crosstalk involving iLECs and macrophages provides a new therapeutic opportunity for lymphatic malformations. Identification of iLECs further indicates that peripheral lymphatic vessels not only respond to but also actively orchestrate inflammatory processes.

Neuronal connectivity and activity-dependent synaptic plasticity are fundamental properties that support brain function and cognitive performance. Phosphatidylinositol 3-kinase (PI3K) intracellular signaling controls multiple mechanisms mediating neuronal growth, synaptic structure, and plasticity. However, it is still unclear how these pleiotropic functions are integrated at molecular and cellular levels. To address this issue, we used neuron-specific virally delivered Cre expression to delete either p110α or p110β (the two major catalytic isoforms of type I PI3K) from the hippocampus of adult mice. We found that dendritic and postsynaptic structures are almost exclusively supported by p110α activity, whereas p110β controls neurotransmitter release and metabotropic glutamate receptor-dependent long-term depression at the presynaptic terminal. In addition to these separate functions, p110α and p110β jointly contribute to N-methyl-d-aspartate receptor-dependent postsynaptic long-term potentiation. This molecular and functional specialization is reflected in different proteomes controlled by each isoform and in distinct behavioral alterations for learning/memory and sociability in mice lacking p110α or p110β. This work was supported by the Spanish Ministry of Science and Innovation grants SAF2017-86983-R and PID2020-117651RB (to J.A.E.), Spanish Ministry of Science and Innovation grants SAF2017-89116R-P (FEDER/EU) and PID2020-116184RB (to M.G.), Carlos III Institute of Health-Fondo de Investigación Sanitaria grant PRB3 (IPT17/0019–ISCIII-SGEFI/ERDF, ProteoRed) and CIBERCV (to J.A.L.), Spanish Ministry of Economy postdoctoral contract IJCI-2015-25507 (to M.I.C.), Marie Curie cofund UAM-UE (EU project 713366) Intertalentum Postdoctoral Program (to V.B.), and Spanish Ministry of Science and Innovation predoctoral contracts (to C.S.-C., A.F.-R., and S.L.-G.). The CNIC is supported by the Instituto de Salud Carlos III (ISCIII), the Ministerio de Ciencia e Innovación (MCIN), and the Pro CNIC Foundation, and is a Severo Ochoa Center of Excellence (grant CEX2020-001041-S funded by MICIN/AEI/10.13039/501100011033). Sí

BackgroundVascular networks form, remodel and mature under the influence of both fluid shear stress (FSS) and soluble factors. For example, FSS synergizes with Bone Morphogenic Protein 9 (BMP9) and BMP10 to promote and maintain vascular stability. Mutation of the BMP receptors ALK1, Endoglin or the downstream effector SMAD4 leads to Hereditary Hemorrhagic Telangiectasia (HHT), characterized by fragile and leaky arterial-venous malformations (AVMs). But how endothelial cells (EC) integrate FSS and BMP signals in normal vascular development and homeostasis, and how mutations give rise to malformations is not well understood.ResultsHere we show that loss of Smad4 in murine ECs increases cells’ sensitivity to flow and the resulting AVMs are characterized by excessive elongation and polarity against the flow. Smad4 deletion also blocks the anti-proliferative response to high FSS, leading to loss of arterial identity. Our data show that loss of cell cycle arrest leads to loss of arterial identity, which is essential in AVM formation upon Smad4 depletion in ECs. Excessive flow-induced activation of KLF4-PI3K/AKT due to Cyclin dependent Kinase (CDK) activation mediates the aberrant morphological responses to flow triggering AVM formation.ConclusionsOur results show that loss of polarization against the flow is not required for AVM formation upon EC Smad4 depletion. Instead, increased EC proliferation-mediated loss of arterial identity due to flow-induced PI3K/Akt/Cdks hyperactivation and Klf4 over-expression are the main events associated with AVM formation.

Vascular malformations are congenital, chronically debilitating diseases. Somatic oncogenic mutations in PIK3CA, encoding p110α-PI3K, specifically cause venous and lymphatic malformations (LM), yet the basis of vessel type-restricted disease manifestation is unknown. Here we report endothelial subtype-specific responses to the common causative Pik3caH1047R mutation, and reveal a new immunoregulatory subtype of dermal lymphatic capillary endothelial cells (iLECs) as a driver of LM pathology. Mouse model of Pik3caH1047R-driven vascular malformations showed that cell proliferation was a common early response of venous and lymphatic ECs to oncogenic Pik3ca, but sustained selectively in LECs of advanced lesions. Lymphatic overgrowth was associated with increased pro-inflammatory cytokine levels and pro-lymphangiogenic myeloid cell infiltrate. Single-cell transcriptomics revealed a new LEC subtype at capillary terminals, characterized by the expression of immunoregulatory genes. Selective expansion and activation of iLECs in the Pik3caH1047R mice was evidenced by proliferation and upregulation of pro-inflammatory genes. Importantly, macrophage depletion or anti-inflammatory COX-2 inhibition limited Pik3caH1047R-driven lymphangiogenesis. This provides a therapeutic target for LM and suggests a paracrine crosstalk in which LEC-autonomous oncogenic Pik3ca signaling induces immune activation that in turn sustains pathological lymphangiogenesis. Identification of iLECs indicates that peripheral lymphatic vessels not only respond to inflammation but also actively orchestrate the immune response.

Transcriptional and proteomic profiling of individual cells have revolutionized interpretation of biological phenomena by providing cellular landscapes of healthy and diseased tissues1,2. These approaches, however, do not describe dynamic scenarios in which cells continuously change their biochemical properties and downstream 'behavioural' outputs3-5. Here we used 4D live imaging to record tens to hundreds of morpho-kinetic parameters describing the dynamics of individual leukocytes at sites of active inflammation. By analysing more than 100,000 reconstructions of cell shapes and tracks over time, we obtained behavioural descriptors of individual cells and used these high-dimensional datasets to build behavioural landscapes. These landscapes recognized leukocyte identities in the inflamed skin and trachea, and uncovered a continuum of neutrophil states inside blood vessels, including a large, sessile state that was embraced by the underlying endothelium and associated with pathogenic inflammation. Behavioural screening in 24 mouse mutants identified the kinase Fgr as a driver of this pathogenic state, and interference with Fgr protected mice from inflammatory injury. Thus, behavioural landscapes report distinct properties of dynamic environments at high cellular resolution. This study was supported by RTI2018-095497-B-I00 from Ministerio de Ciencia e Innovación (MCIN), HR17_00527 from Fundación La Caixa, Transatlantic Network of Excellence (TNE-18CVD04) from the Leducq Foundation, and FET-OPEN (no. 861878) from the European Commission to A.H. M.P-S. is supported by a Federation of European Biochemical Societies and the EMBO ALTF (no. 1142-2020) long-term fellowships. J.S. is supported by a fellowship (PRE2019-089130) from MICINN and A.A.-C. is supported by fellowship CF/BQ/ DR19/11740022 from La Caixa Foundation. J.L.Y.L. was supported by A*STAR and a Juan de la Cierva JCI-2017-33136 Fellowship from MICINN. S.D.C. is a recipient of a Marie Sklodowska-Curie fellowship (749731). M.G. is supported by SAF2017-89116R-P from MCIN and HR18_00120 from la Fundación La Caixa. T.R.M. is supported by grant NIH AI163223, L.G.N. is supported by SIgN core funding from A*STAR, and G.F.C. is supported by MCIN/ AEI/10.13039/501100011033 (grant PID2019-110895RB-I00) and by Junta de Comunidades de Castilla-La Mancha (SBPLY/19/180501/000211). F.S.-C. is supported by MCIN (grant RTI2018- 102084-B-I00), O.S. is supported by the Leducq Foundation (TNE-18CVD04), F.D.-d.-M. is supported by MCIN (TEC2017-84395-P), and T.E.S. is supported by the National Cancer Institute, NIH grant CA233576. The CNIC is supported by the MCIN and the Pro-CNIC Foundation. Sí

Low-flow vascular malformations are congenital overgrowths composed by abnormal blood vessels potentially causing pain, bleeding, and obstruction of different organs. These diseases are caused by oncogenic mutations in the endothelium which result in overactivation of the PI3K/AKT pathway. Lack of robust in vivo preclinical data has prevented the development and translation into clinical trials of specific molecular therapies for these diseases. Here, we describe a new reproducible preclinical in vivo model of PI3K-driven vascular malformations using the postnatal mouse retina. This model reproduces human disease with Pik3ca activating mutations expressed in a mosaic pattern and vascular malformations formed in veins and capillaries. We show that active angiogenesis is required for the pathogenesis of vascular malformations caused by activating Pik3ca mutations. Using this model, we demonstrate that low doses of the AKT inhibitor miransertib both prevents and induces the regression of PI3K-driven vascular malformations. We confirmed miransertib efficacy in isolated human endothelial cells with genotypes spanning most of human low-flow vascular malformations.Graphical abstractLow-flow vascular malformations are caused by PI3K signalling overactivation in endothelial cells. We have generated an optimised and robust preclinical system of PI3K-driven vascular malformations by inducing the mosaic expression of Pik3caH1047R in the retinal angiogenic endothelium. This preclinical model displays traits constituting the main hallmarks of the pathogenesis of low-flow blood vascular malformations: overactivation of PI3K signalling (high phospho-S6), vascular compartment specificity, loss of pericyte coverage, and endothelial cell hyperproliferation. Using this preclinical model we report that low dose AKT inhibitor miransertib prevents and regress PI3K-driven vascular malformations.

Here, we used preclinical models and patient samples to identify predictive biomarkers to these drugs. We evaluated the antitumor activity of an FGFRi and an MTKI in a collection of 17 breast cancer patient-derived xenografts (PDXs) harboring amplification inHighTailored therapy with FGFRis in molecularly selected MBC based on high