Anti.-tumor activity of FGFR3-specific immunotoxins in a xenograft mouse model of bladder carcinoma

12 páginas, 6 figuras -- PAGS nros. 462-473Human single-chain Fv directed against fibroblast growth factor receptor 3 (FGFR3) have been shown to block proliferation of RT112 bladder carcinoma cells in vitro. Here, we examined the ability of the recombinant gelonin toxin (rGel) to enhance this inhibitory effect in vitro and in vivo on the bladder cancer cell line RT112 and the corresponding xenografts. Immunotoxins were genetically engineered by fusing FGFR3-specific Fv fragments (3C) to the NH2 terminus of rGel and expressed as a soluble protein in Escherichia coli. The 3C/rGel fusion construct showed an IC50 of 200 nmol/L against log-phase RT112 cells compared with 1,500 nmol/L for free rGel. Immunofluorescence studies showed that the 3C/rGel construct internalized rapidly into the cytoplasm of RT112 cells within 1 h of exposure. The mechanism of immunotoxin-induced cell death was found to be mediated by apoptosis. RT112 tumor xenografts in severe combined immunodeficient mice treated with 50 mg/kg 3C/rGel exhibited considerable growth delay relative to control tumors and a significant reduction of 55% to 70% in mean tumor size. Immunohistochemical analysis showed that tumors from mice treated with 3C/rGel displayed considerable apoptotic damage compared with control groups. Subcellular location of FGFR3 in immunotoxin-treated tumors indicated a translocation of FGFR3 to the nuclear membrane in contrast to tumors from saline-treated controls. These results show that FGFR3-driven immunotoxins may be an effective therapeutic agent against human bladder and other tumor types overexpressing FGFR3Spanish Ministry of Education and Science grant PTR1995-0849-OP, Comunidad Autónoma de Madrid grant S-BIO/0236/2006 and CDTI grant “CDTEAM” The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.Peer reviewe

Whole-body imaging of lymphovascular niches identifies pre-metastatic roles of midkine

Cutaneous melanoma is a type of cancer with an inherent potential for lymph node colonization, which is generally preceded by neolymphangiogenesis1,2,3. However, sentinel lymph node removal does not necessarily extend the overall survival of patients with melanoma4,5. Moreover, lymphatic vessels collapse and become dysfunctional as melanomas progress6,7. Therefore, it is unclear whether (and how) lymphangiogenesis contributes to visceral metastasis. Soluble and vesicle-associated proteins secreted by tumours and/or their stroma have been proposed to condition pre-metastatic sites in patients with melanoma8,9,10,11,12,13,14. Still, the identities and prognostic value of lymphangiogenic mediators remain unclear2,14. Moreover, our understanding of lymphangiogenesis (in melanomas and other tumour types) is limited by the paucity of mouse models for live imaging of distal pre-metastatic niches15. Injectable lymphatic tracers have been developed7, but their limited diffusion precludes whole-body imaging at visceral sites16. Vascular endothelial growth factor receptor 3 (VEGFR3) is an attractive ‘lymphoreporter’17 because its expression is strongly downregulated in normal adult lymphatic endothelial cells, but is activated in pathological situations such as inflammation and cancer17,18. Here, we exploit this inducibility of VEGFR3 to engineer mouse melanoma models for whole-body imaging of metastasis generated by human cells, clinical biopsies or endogenously deregulated oncogenic pathways. This strategy revealed early induction of distal pre-metastatic niches uncoupled from lymphangiogenesis at primary lesions. Analyses of the melanoma secretome and validation in clinical specimens showed that the heparin-binding factor midkine is a systemic inducer of neo-lymphangiogenesis that defines patient prognosis. This role of midkine was linked to a paracrine activation of the mTOR pathway in lymphatic endothelial cells. These data support the use of VEGFR3 reporter mice as a ‘MetAlert’ discovery platform for drivers and inhibitors of metastasis.M.S.S. is funded by grants from the Spanish Ministry of Economy and Innovation (project SAF2014-56868-R), the Asociación Española Contra el Cáncer (AECC), the Worldwide Cancer Research, an Established Investigator Award from the Melanoma Research Alliance (MRA), and a L’Oréal Paris USA-MRA Team Science Award for Woman in Scientific Research. The CNIO Proteomics Unit belongs to ProteoRed, PRB2-ISCIII, supported by grant PT13/0001. N.I. and J.M. are funded by SAF2013-45504-R (MINECO). J.M. is also supported by Ramon y Cajal Programme (MINECO) RYC-2012-10651. J.L.R.-P and P.O.-R are funded by grants FIS 2014/1737, 11/02568 and FIS 2014/01784, 11/1759, respectively, from the Spanish Ministry of Health. F.M. is funded by the AMIT Project/CDTI/CENIT Programme (MICINN), S.O. by SAF2013-44866-R (MINECO), and J.J.B.-C. by an NCI K22CA196750 grant and the TCI Young Scientist Cancer Research Award JJR Fund (P30 CA196521). J.D.M. is the recipient of a postdoctoral fellowship from the ARC Foundation and E.R.-F. from Fundación Científica de la Asociación Española Contra el Cáncer. D.C.-W. is the recipient of a predoctoral fellowship from Fundación La Caixa, and M.C.-A. and X.C. are recipients of the Immutrain Marie Skłodowska-Curie ITN Grant.Peer reviewe

Plk1 regulates contraction of postmitotic smooth muscle cells and is required for vascular homeostasis

Polo-like kinase 1 (PLK1), an essential regulator of cell division, is currently undergoing clinical evaluation as a target for cancer therapy. We report an unexpected function of Plk1 in sustaining cardiovascular homeostasis. Plk1 haploinsufficiency in mice did not induce obvious cell proliferation defects but did result in arterial structural alterations, which frequently led to aortic rupture and death. Specific ablation of Plk1 in vascular smooth muscle cells (VSMCs) led to reduced arterial elasticity, hypotension, and an impaired arterial response to angiotensin II in vivo. Mechanistically, we found that Plk1 regulated angiotensin II-dependent activation of RhoA and actomyosin dynamics in VSMCs in a mitosis-independent manner. This regulation depended on Plk1 kinase activity, and the administration of small-molecule Plk1 inhibitors to angiotensin II-treated mice led to reduced arterial fitness and an elevated risk of aneurysm and aortic rupture. We thus conclude that a partial reduction of Plk1 activity that does not block cell division can nevertheless impair aortic homeostasis. Our findings have potentially important implications for current approaches aimed at PLK1 inhibition for cancer therapy.This work-was supported by the Marie Curie activities of the European Commission (Oncotrain program; fellowship to P.W), the Spanish Ministry of Economy and Competitiveness (MINECO; fellowship to A.G.-L.), the CENIT AMIT Project "Advanced Molecular Imaging Technologies" (TEC2008-06715-C02-1, RD07/0014/2009 to F.M.), the Red de investigacion Cardiovascular (RIC), cofunded by FEDER (grant RD12/004240022 to J.M.R.; grant RD12/0042/0056 to L.J.J.-B), Fundacio La Marato TV3 (grant 20151331 to J.M.R.), the Castilla-Leon Autonomous Government (BIO/SA01/15, CS049U16 to X.R.B.), the Solorzano and Ramon Areces Foundations (to X.R.B.), MINECO (grants RD12/0036/0002 and SAF2015-64556-R to X.R.B.; SAF2015-63633-R to J.M.R.; and SAF2015-69920-R to M.M.), Consolider-Ingenio 2010 Programme (grant SAF2014-57791-REDC to M.M.), Red Tematica CellSYS (grant BFU2014-52125-REDT to M.M.), Comunidad de Madrid (OncoCycle Programme; grant S2010/BMD-2470 to M.M.), Worldwide Cancer Research (grants 14-1248 to X.R.B., and 15-0278 to M.M.) and the MitoSys project (European Union Seventh Framework Programme; grant HEALTH-F5-2010-241548 to M.M.). CNIC is supported by MINECO and the Pro-CNIC Foundation. CNIO and CNIC are Severo Ochoa Centers of Excellence (MINECO awards SEV-2015-0510 and SEV-2015-0505, respectively).S

Timing of onset affects arthritis presentation pattern in antisyntethase syndrome

OBJECTIVES: To evaluate if the timing of appearance with respect to disease onset may influence the arthritis presentation pattern in antisynthetase syndrome (ASSD). METHODS: The patients were selected from a retrospective large international cohort of ASSD patients regularly followed-up in centres referring to AENEAS collaborative group. Patients were eligible if they had an antisynthetase antibody testing positive in at least two determinations along with arthritis occurring either at ASSD onset (Group 1) or during the course of the disease (Group 2). RESULTS: 445 (70%; 334 females, 110 males, 1 transsexual) out of the 636 ASSD we collected had arthritis, in the majority of cases (367, 83%) from disease onset (Group 1). Patients belonging to Group 1 with respect to Group 2 had an arthritis more commonly polyarticular and symmetrical (p=0.015), IgM-Rheumatoid factor positive (p=0.035), erosions at hands and feet plain x-rays (p=0.036) and more commonly satisfying the 1987 revised classification criteria for rheumatoid arthritis (RA) (p=0.004). Features such as Raynaud's phenomenon, mechanic's hands and fever (e.g. accompanying findings) were more frequently reported in Group 2 (p=0.005). CONCLUSIONS: In ASSD, the timing of appearance with respect to disease onset influences arthritis characteristics. In particular, RA features are more common when arthritis occurs from ASSD onset, suggesting an overlap between RA and ASSD in these patients. When arthritis appears during the follow-up, it is very close to a connective tissue disease-related arthritis. Also, the different prevalence of accompanying features between these two groups is in line with this possibility

Timing of onset affects arthritis presentation pattern in antisyntethase syndrome

445 (70%; 334 females, 110 males, 1 transsexual) out of the 636 ASSD we collected had arthritis, in the majority of cases (367, 83%) from disease onset (Group 1). Patients belonging to Group 1 with respect to Group 2 had an arthritis more commonly polyarticular and symmetrical (p=0.015), IgM-Rheumatoid factor positive (p=0.035), erosions at hands and feet plain x-rays (p=0.036) and more commonly satisfying the 1987 revised classification criteria for rheumatoid arthritis (RA) (p=0.004). Features such as Raynaud's phenomenon, mechanic's hands and fever (e.g. accompanying findings) were more frequently reported in Group 2 (p=0.005). In ASSD, the timing of appearance with respect to disease onset influences arthritis characteristics. In particular, RA features are more common when arthritis occurs from ASSD onset, suggesting an overlap between RA and ASSD in these patients. When arthritis appears during the follow-up, it is very close to a connective tissue disease-related arthritis. Also, the different prevalence of accompanying features between these two groups is in line with this possibility