| 1. |
- Bartoschek, Michael, et al.
(författare)
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Spatially and functionally distinct subclasses of breast cancer-associated fibroblasts revealed by single cell RNA sequencing
- 2018
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- Cancer-associated fibroblasts (CAFs) are a major constituent of the tumor microenvironment, although their origin and roles in shaping disease initiation, progression and treatment response remain unclear due to significant heterogeneity. Here, following a negative selection strategy combined with single-cell RNA sequencing of 768 transcriptomes of mesenchymal cells from a genetically engineered mouse model of breast cancer, we define three distinct subpopulations of CAFs. Validation at the transcriptional and protein level in several experimental models of cancer and human tumors reveal spatial separation of the CAF subclasses attributable to different origins, including the peri-vascular niche, the mammary fat pad and the transformed epithelium. Gene profiles for each CAF subtype correlate to distinctive functional programs and hold independent prognostic capability in clinical cohorts by association to metastatic disease. In conclusion, the improved resolution of the widely defined CAF population opens the possibility for biomarker-driven development of drugs for precision targeting of CAFs.
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| 2. |
- Bocci, Matteo, et al.
(författare)
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Activin receptor-like kinase 1 is associated with immune cell infiltration and regulates CLEC14A transcription in cancer
- 2019
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Ingår i: Angiogenesis. - : Springer Science and Business Media LLC. - 0969-6970 .- 1573-7209. ; 22:1, s. 117-131
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Tidskriftsartikel (refereegranskat)abstract
- Cancer cells sustain their metabolic needs through nutrients and oxygen supplied by the bloodstream. The requirement for tumor angiogenesis has been therapeutically exploited in the clinical setting mainly by means of inhibition of the vascular endothelial growth factor family of ligands and receptors. Despite promising results in preclinical models, the benefits for patients proved to be limited. Inadequate efficacy similarly halted the development of agents impinging on the activity of the activin receptor-like kinase (ALK)1, a member of the transforming growth factor-β superfamily. Notwithstanding its characterization as an endothelial cell marker, the full spectrum of biological processes associated with ALK1 is essentially unexplored. Here, we present data revealing the genetic network associated with ACVRL1 (the gene encoding for ALK1) expression in human cancer tissues. Computational analysis unveiled a hitherto unknown role for ACVRL1 in relation to genes modulating the functionality of the immune cell compartment. Moreover, we generated a signature of 8 genes co-expressed with ACVRL1 across different tumor types and characterized the c-type lectin domain containing protein (CLEC)14A as a potential downstream target of ACVRL1. Considering the lack of reagents for ALK1 detection that has hampered the field to date, our work provides the opportunity to validate the 8-gene signature and CLEC14A as biomarkers for ALK1 activity. Ultimately, this may help revisit the clinical development of already existing ALK1-blocking compounds as precision medicines for cancer.
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| 3. |
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| 4. |
- Bocci, Matteo
(författare)
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Growth factor signaling in the breast tumor microenvironment
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Cancer represents a collection of malignancies characterized by an aberrant expansion of cells. This unrestrained growth is the result of the acquisition of several pro-survival features and the evasion of cellular fail-safe mechanisms, collectively known as the hallmarks of cancer. In the clinical setting, disease management has heavily relied on the sole targeting of malignant cells but, except for rare cases, monotherapy regimens showed insufficient antitumor activity. Indeed, translational and clinical studies revealed that cancer cells almost invariably adapt to treatment, mainly through acquisition of additional (epi)mutations and/or clonal diversification and activation of bypass signaling pathways. In parallel, characterization of the malignant mass exposed the existence of other (non- transformed) cell types and non-cellular constituents, with specialized functions and potentially different origins, jointly reffered to as the tumor stroma. This local microenvironment is educated by and coevolves with the cancer cells by engaging in an intricate network of communication that plays a fundamental role in the establishment, progression and malignization of a tumor, as well as modulating the response to treatment. The stroma comprises the endothelial cells and pericytes that compose the vasculature, fibroblasts, immune cells and the extracellular matrix. Therefore, the genetic make-up of polyclonal tumors and the composition of the microenvironment define the genomic, spatial and functional diversity of each tumor, also at the metastatic site. In agreement with this, the concept of intratumoral heterogeneity denotes a key aspect that has been increasingly recognized, although not fully implemented, in personalized medicine. Moreover, recent efforts have started to address the systemic changes instigated by the tumor mass –including metabolism– and how these influence the survival/dormancy, the colonization and the metastatic growth of disseminated cancer cells.In the papers included in this thesis, we made use of experimental breast cancer models to deepen our understanding of the tumor milieu and its clinical implications. Paper I reports the results of the preclinical trials of a compound that was designed to block activin receptor-like kinase (ALK)1, a protein involved in the formation of the blood vessels. Experimental models showed promising inhibition of tumor growth and marked reduction of the metastatic disease. In paper II, we analyzed how ALK1 communicates in different tumors in order to determine a set of characteristics that might help to predict which patients could benefit from ALK1-blocking therapy. Moreover, we discovered that the presence of ALK1 in tumor blood vessels influences the presence and function of the immune cells. In paper III, we define a novel therapeutic opportunity for the basal subtype of breast cancer, for which only surgery, radio- and chemotherapy are currently available. We identified the specific role of PDGF-C, that is released by tumor cells to activate fibroblasts. This communication loop maintains the tumor cells in a more aggressive state and makes them resistant to treatment. Thus, by blocking PDGF-C, tumor cells transform to a less aggressive luminal type and become sensitive to endocrine therapy, which can be used to limit the development of the tumor mass. Finally, paper IV gives us information about the diversity of the cells within the fibroblast population. By using a state of the art technology, we increased the resolution at which we are able to distinguish the function of each individual fibroblast isolated from a tissue, and match it with a specific cell-of-origin.Taken together, the use of mouse models of cancer allows us to reproduce the complexity of human tumors, and delineate how these cellular relationships are shaped and maintained during tumor development. Our data illustrate the value of impinging on the crosstalk between tumor cells and other components of the tumor mass to develop novel therapeutic strategies for the clinical management of breast cancer.
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| 5. |
- Bocci, Matteo, et al.
(författare)
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Infection of Brain Pericytes Underlying Neuropathology of COVID-19 Patients.
- 2021
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Ingår i: International journal of molecular sciences. - : MDPI AG. - 1422-0067 .- 1661-6596. ; 22:21
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Tidskriftsartikel (refereegranskat)abstract
- A wide range of neurological manifestations have been associated with the development of COVID-19 following SARS-CoV-2 infection. However, the etiology of the neurological symptomatology is still largely unexplored. Here, we used state-of-the-art multiplexed immunostaining of human brains (n = 6 COVID-19, median age = 69.5 years; n = 7 control, median age = 68 years) and demonstrated that expression of the SARS-CoV-2 receptor ACE2 is restricted to a subset of neurovascular pericytes. Strikingly, neurological symptoms were exclusive to, and ubiquitous in, patients that exhibited moderate to high ACE2 expression in perivascular cells. Viral dsRNA was identified in the vascular wall and paralleled by perivascular inflammation, as signified by T cell and macrophage infiltration. Furthermore, fibrinogen leakage indicated compromised integrity of the blood-brain barrier. Notably, cerebrospinal fluid from additional 16 individuals (n = 8 COVID-19, median age = 67 years; n = 8 control, median age = 69.5 years) exhibited significantly lower levels of the pericyte marker PDGFRβ in SARS-CoV-2-infected cases, indicative of disrupted pericyte homeostasis. We conclude that pericyte infection by SARS-CoV-2 underlies virus entry into the privileged central nervous system space, as well as neurological symptomatology due to perivascular inflammation and a locally compromised blood-brain barrier.
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| 6. |
- Cortez, Eliane, et al.
(författare)
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Functional malignant cell heterogeneity in pancreatic neuroendocrine tumors revealed by targeting of PDGF-DD.
- 2016
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Ingår i: Proceedings of the National Academy of Sciences. - : Proceedings of the National Academy of Sciences. - 1091-6490 .- 0027-8424. ; 113:7, s. 864-873
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Tidskriftsartikel (refereegranskat)abstract
- Intratumoral heterogeneity is an inherent feature of most human cancers and has profound implications for cancer therapy. As a result, there is an emergent need to explore previously unmapped mechanisms regulating distinct subpopulations of tumor cells and to understand their contribution to tumor progression and treatment response. Aberrant platelet-derived growth factor receptor beta (PDGFRβ) signaling in cancer has motivated the development of several antagonists currently in clinical use, including imatinib, sunitinib, and sorafenib. The discovery of a novel ligand for PDGFRβ, platelet-derived growth factor (PDGF)-DD, opened the possibility of a previously unidentified signaling pathway involved in tumor development. However, the precise function of PDGF-DD in tumor growth and invasion remains elusive. Here, making use of a newly generated Pdgfd knockout mouse, we reveal a functionally important malignant cell heterogeneity modulated by PDGF-DD signaling in pancreatic neuroendocrine tumors (PanNET). Our analyses demonstrate that tumor growth was delayed in the absence of signaling by PDGF-DD. Surprisingly, ablation of PDGF-DD did not affect the vasculature or stroma of PanNET; instead, we found that PDGF-DD stimulated bulk tumor cell proliferation by induction of paracrine mitogenic signaling between heterogeneous malignant cell clones, some of which expressed PDGFRβ. The presence of a subclonal population of tumor cells characterized by PDGFRβ expression was further validated in a cohort of human PanNET. In conclusion, we demonstrate a previously unrecognized heterogeneity in PanNET characterized by signaling through the PDGF-DD/PDGFRβ axis.
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| 7. |
- Cunha, Sara I., et al.
(författare)
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Endothelial ALK1 Is a Therapeutic Target to Block Metastatic Dissemination of Breast Cancer.
- 2015
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Ingår i: Cancer Research. - 1538-7445 .- 0008-5472. ; 75:12, s. 2445-2456
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Tidskriftsartikel (refereegranskat)abstract
- Exploration of new strategies for the prevention of breast cancer metastasis is justifiably at the center of clinical attention. In this study, we combined a computational biology approach with mechanism-based preclinical trials to identify inhibitors of activin-like receptor kinase (ALK) 1 as effective agents for blocking angiogenesis and metastasis in breast cancer. Pharmacologic targeting of ALK1 provided long-term therapeutic benefit in mouse models of mammary carcinoma, accompanied by strikingly reduced metastatic colonization as a monotherapy or part of combinations with chemotherapy. Gene-expression analysis of breast cancer specimens from a population-based nested case-control study encompassing 768 subjects defined endothelial expression of ALK1 as an independent and highly specific prognostic factor for metastatic manifestation, a finding that was corroborated in an independent clinical cohort. Overall, our results suggest that pharmacologic inhibition of endothelial ALK1 constitutes a tractable strategy for interfering with metastatic dissemination of breast cancer. Cancer Res; 75(12); 2445-56. ©2015 AACR.
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| 8. |
- De Vinuesa, Amaya García, et al.
(författare)
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Targeting tumour vasculature by inhibiting activin receptor-like kinase (ALK)1 function
- 2016
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Ingår i: Biochemical Society Transactions. - 0300-5127. ; 44:4, s. 1142-1149
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Tidskriftsartikel (refereegranskat)abstract
- Angiogenesis is a hallmark of cancer and is now a validated therapeutic target in the clinical setting. Despite the initial success, anti-angiogenic compounds impinging on the vascular endothelial growth factor (VEGF) pathway display limited survival benefits in patients and resistance often develops due to activation of alternative pathways. Thus, finding and validating new targets is highly warranted. Activin receptor-like kinase (ALK)1 is a transforming growth factor beta (TGF-β) type I receptor predominantly expressed in actively proliferating endothelial cells (ECs). ALK1 has been shown to play a pivotal role in regulating angiogenesis by binding to bone morphogenetic protein (BMP)9 and 10. Two main pharmacological inhibitors, an ALK1-Fc fusion protein (Dalantercept/ACE-041) and a fully human antibody against the extracellular domain of ALK1 (PF-03446962) are currently under clinical development. Herein, we briefly recapitulate the role of ALK1 in blood vessel formation and the current status of the preclinical and clinical studies on inhibition of ALK1 signalling as an anti-angiogenic strategy. Future directions in terms of new combination regimens will also be presented.
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| 9. |
- Eleftheriou, Nikolas M., et al.
(författare)
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Compound genetically engineered mouse models of cancer reveal dual targeting of ALK1 and endoglin as a synergistic opportunity to impinge on angiogenic TGF-β signaling
- 2016
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Ingår i: Oncotarget. - : Impact Journals, LLC. - 1949-2553. ; 7:51, s. 84314-84325
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Tidskriftsartikel (refereegranskat)abstract
- Angiogenesis occurs early in tumor development, sustains primary tumor growth and provides a route for metastatic escape. The TGF-β family receptors modulate angiogenesis via endothelial-cell specific pathways. Here we investigate the interaction of two such receptors, ALK1 and endoglin, in pancreatic neuroendocrine tumors (PanNET). Independently, ALK1 and endoglin deficiencies exhibited genetically divergent phenotypes, while both highly correlate to an endothelial metagene in human and mouse PanNETs. A concurrent deficiency of both receptors synergistically decreased tumor burden to a greater extent than either individual knockdown. Furthermore, the knockout of Gdf2 (BMP9), the primary ligand for ALK1 and endoglin, exhibited a mixed phenotype from each of ALK1 and endoglin deficiencies; overall primary tumor burden decreased, but hepatic metastases increased. Tumors lacking BMP9 display a hyperbranching vasculature, and an increase in vascular mesenchymal-marker expression, which may be implicit in the increase in metastases. Taken together, our work cautions against singular blockade of BMP9 and instead demonstrates the utility of dual blockade of ALK1 and endoglin as a strategy for antiangiogenic therapy in PanNET.
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| 10. |
- Jung, Christian, et al.
(författare)
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A comparison of very old patients admitted to intensive care unit after acute versus elective surgery or intervention
- 2019
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Ingår i: Journal of critical care. - : W B SAUNDERS CO-ELSEVIER INC. - 0883-9441 .- 1557-8615. ; 52, s. 141-148
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Tidskriftsartikel (refereegranskat)abstract
- Background: We aimed to evaluate differences in outcome between patients admitted to intensive care unit (ICU) after elective versus acute surgery in a multinational cohort of very old patients (80 years; VIP). Predictors of mortality, with special emphasis on frailty, were assessed.Methods: In total, 5063 VIPs were induded in this analysis, 922 were admitted after elective surgery or intervention, 4141 acutely, with 402 after acute surgery. Differences were calculated using Mann-Whitney-U test and Wilcoxon test. Univariate and multivariable logistic regression were used to assess associations with mortality.Results: Compared patients admitted after acute surgery, patients admitted after elective surgery suffered less often from frailty as defined as CFS (28% vs 46%; p < 0.001), evidenced lower SOFA scores (4 +/- 5 vs 7 +/- 7; p < 0.001). Presence of frailty (CFS >4) was associated with significantly increased mortality both in elective surgery patients (7% vs 12%; p = 0.01), in acute surgery (7% vs 12%; p = 0.02).Conclusions: VIPs admitted to ICU after elective surgery evidenced favorable outcome over patients after acute surgery even after correction for relevant confounders. Frailty might be used to guide clinicians in risk stratification in both patients admitted after elective and acute surgery.
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