1,721,101 research outputs found
Stromal delivery of long Pentraxin-3 impairsFGF7FGFR-dependent tumor growth and metastasis
No full textThe FGF/FGFR system contributes to cancer progression by inducing tumor growth and neovascularization, thus representing an emerging therapeutic target. Long Pentraxin-3 (PTX3) is a soluble pattern recognition receptor expressed by endothelial and immune cells in inflammatory contexts. Among various ligands, PTX3 binds different members of the FGF family, acting as a natural FGF ligand trap.
Here, we generated transgenic mice expressing human (h)PTX3 under the control of endothelial specific Tie2/Tek transcription regulatory sequences (Tie2-hPTX3 mice). These animals accumulate significant levels of hPTX3 in perivascular stroma and in the blood stream. On this basis, Tie2-hPTX3 mice were used to investigate the impact of stroma-derived hPTX3 on tumor growth, vascularization and metastasis.
hPTX3 overexpression inhibits angiogenesis in transgenic mice as observed in ex vivo aorta ring and in vivo matrigel plug assays. Next, various syngeneic FGF-dependent tumor cell lines, including TRAMP-C2 prostate carcinoma, B16-F10 melanoma and Lewis Lung carcinoma cells, were injected subcutaneously in Tie2-hPTX3 mice. Notably, the growth of all tumor grafts was significantly reduced in Tie2-hPTX3 mice when compared to wild type animals and was accompanied by a significant inhibition of FGFR1 phosphorylation, tumor vascularization and tumor cell proliferation. In addition, B16-F10 melanoma and M5076 ovarian sarcoma cells showed a dramatic decrease of their capacity to form experimental metastases in the lung and liver, respectively, when injected intravenously in Tie2-hPTX3 mice. Also, the orthotopic growth of syngeneic pancreatic and mammary tumor cells was significantly reduced after injection in Tie2-hPTX3 mice and led to increased survival compared to control mice. Finally, double transgenic TRAMP/Tie2-hPTX3 mice showed a significant delay of multistage prostate tumor onset and progression in respect to TRAMP mice.
Our findings demonstrate for the first time that in vivo delivery of PTX3 exerts a dramatic impact on tumor growth, vascularization and metastasis. These results have set the basis for the identification of a low molecular weight PTX3-derived molecule that recapitulates the FGF-trap activities of PTX3 and exhibits promising therapeutic potential for FGF-dependent tumors
Carbonic anhydrase IX: An atypical target for innovative therapies in cancer
Full text link: Carbonic anhydrases (CAs), are metallo-enzymes implicated in several pathophysiological processes where tissue pH regulation is required. CA IX is a tumor-associated CA isoform induced by hypoxia and involved in the adaptation of tumor cells to acidosis. Indeed, several tumor-driving pathways can induce CA IX expression, and this in turn has been associated to cancer cells invasion and metastatic features as well as to induction of stem-like features, drug resistance and recurrence. After its functional and structural characterization CA IX targeting approaches have been developed to inhibit its activity in neoplastic tissues, and to date this field has seen an incredible acceleration in terms of therapeutic options and biological readouts. Small molecules inhibitors, hybrid/dual targeting drugs, targeting antibodies and adoptive (CAR-T based) cell therapy have been developed at preclinical level, whereas a sulfonamide CA IX inhibitor and an antibody entered Phase Ib/II clinical trials for the treatment and imaging of different solid tumors. Here recent advances on CA IX biology and pharmacology in cancer, and its therapeutic targeting will be discussed
Targeting FGF/FGFR1 system for an integrated anti-tumor/anti-angiogenic therapy of cancer
No full textFibroblast growth factors (FGFs) represent a family structurally related growth factors that promote a wide range of biological effects by interacting with different FGF receptors (FGFRs) in target cells. Among the different FGFRs, FGFR1 is expressed by various tumor cell types as well as by tumor endothelial cells and plays a prominent role in both tumor cell and stromal cell compartments of the neoplastic tissue by mediating tumor angiogenesis, growth and invasiveness.
Humanized antibodies in single-chain fragment variable format (scFv) are antibody fragments with improved pharmacokinetics for tissue penetration and can be easily conjugated allowing their use as cytokine, radionuclide, or drug carriers. Our group identified scFv_RR-C2 as a neutralizing recombinant scFv antibody specific for the extracellular domain of the FGFR1. We screened a human single-chain fragment variable (scFv) antibody phage display library against the extracellular domain of the FGFR-1-IIIc isoform that harbors the FGF binding site. Several phages were isolated and tested for specificity and sensitivity, and the most promising antibody fragment RR-C2 was characterized for its biochemical and biological properties. ScFv RR-C2 specifically recognizes FGFR-1 with a Kd value of ~150 nM. The antibody fragment also recognizes FGFR-1 when the receptor is exposed on the cell surface, thus preventing the formation of the ternary complex among FGFR-1, its ligand FGF2, and cell surface heparan sulfate proteoglycans. Accordingly, scFv RR-C2 specifically inhibits FGF2-mediated mitogenic activity in endothelial cells of human, bovine, and murine origin in a nanomolar range of concentrations. Also, the antibody fragment prevents FGF2-triggered sprouting of both human umbilical vein endothelial cell spheroids and of murine endothelium from aortic rings, and hampers the angiogenic activity exerted both by FGF2 in the chick embryo chorioallantoic membrane assay and by S115 mouse mammary tumor cells in the Matrigel plug assay.
Indeed, anti-FGFR1 scFv fragment specifically impairs the proliferation triggered by FGF/FGFR1 autocrine and paracrine loops of stimulation in murine models of prostate (TRAMPC2), melanoma (B16-F10 ) and lung cancer (3LL).
The antibody-mediated anti-FGFR1 therapy will target both tumor endothelium, overcoming resistance to anti-VEGF-targeting therapy, and FGFR1-expressing cancer cells.
Forthcoming experiments will provide novel scFv antibodies endowed with more potent targeting and neutralizing activity against FGFR1
FGFR-1 as an anti-angiogenic/anti-tumor target for squamous cell lung cancer therapy.
No full textFibroblast growth factors (FGFs) represent a family structurally related growth factors that promote a wide range of biological effects by interacting with different FGF receptors (FGFRs) in target cells. Among the different FGFRs, FGFR1 is expressed by various tumor cell types as well as by tumor endothelial cells and plays a prominent role in both tumor cell and stromal cell compartments of the neoplastic tissue by mediating tumor angiogenesis, growth and invasiveness.
Lung cancer is the leading cause of cancer-related mortality worldwide and clinical evidences indicate that FGFR1 gene amplification represents the most common genetic alteration in human squamous cell lung cancer. Also, lung cancer cell lines displaying FGFR1 amplification are highly sensitive to FGFR inhibitors in vitro and in vivo, supporting the hypothesis that FGFR1 may represent a promising target for the therapy of human squamous cell lung cancer.
Humanized antibodies in single-chain fragment variable format (scFv) are antibody fragments with improved pharmacokinetics for tissue penetration and can be easily conjugated allowing their use as cytokine, radionuclide, or drug carriers. Recently, our group identified scFv_RR-C2 as a neutralizing recombinant scFv antibody specific for the extracellular domain of the FGFR1. We screened a human single-chain fragment variable (scFv) antibody phage display library against the extracellular domain of the FGFR-1-IIIc isoform that harbors the FGF binding site. Several phages were isolated and tested for specificity and sensitivity, and the most promising antibody fragment RR-C2 was characterized for its biochemical and biological properties. ScFv RR-C2 specifically recognizes FGFR-1 with a Kd value of ~150 nM. The antibody fragment also recognizes FGFR-1 when the receptor is exposed on the cell surface, thus preventing the formation of the ternary complex among FGFR-1, its ligand FGF2, and cell surface heparan sulfate proteoglycans. Accordingly, scFv RR-C2 specifically inhibits FGF2-mediated mitogenic activity in endothelial cells of human, bovine, and murine origin in a nanomolar range of concentrations. Also, the antibody fragment prevents FGF2-triggered sprouting of both human umbilical vein endothelial cell spheroids and of murine endothelium from aortic rings, and hampers the angiogenic activity exerted both by FGF2 in the chick embryo chorioallantoic membrane assay and by S115 mouse mammary tumor cells in the Matrigel plug assay.
Indeed, anti-FGFR1 scFv fragment specifically impairs the proliferation triggered by FGF/FGFR1 autocrine and paracrine loops of stimulation in murine models of prostate (TRAMPC2), melanoma (B16-F10 ) and lung cancer (3LL).
The antibody-mediated anti-FGFR1 therapy of human squamous cell lung cancer, and of other FGFR1-overexpressing tumors, will target tumor endothelium, overcoming resistance to anti-VEGF-targeting therapy, and FGFR1-amplified cancer cells. Forthcoming experiments will characterize the anti-tumor effect of scFv_RR-C2 in FGFR1-amplified human lung cancer and provide novel scFv antibodies endowed with more potent targeting and neutralizing activity against FGFR1
Inflammatory cells and chemokines sustain FGF2-induced angiogenesis
No full textAngiogenesis and inflammation are closely integrated processes in a number of physiological and pathological conditions, including wound healing, psoriasis, diabetic retinopathy, rheumatoid arthritis, arteriosclerosis, and cancer. Fibroblast growth factor-2 (FGF2) belongs to the family of the heparin-binding FGF growth factors. FGF2 exerts its pro-angiogenic activity by interacting with various endothelial cell surface receptors, including tyrosine kinase receptors, heparan-sulfate proteoglycans, and integrins. Elevated levels of FGF2 have been implicated in the pathogenesis of several diseases characterized by a deregulated angiogenic/inflammatory response. FGF2 induces the expression of a wide repertoire of inflammation-related genes in endothelial cells, including pro-inflammatory cytokines/chemokines and their receptors, endothelial cell adhesion molecules, and components of the prostaglandin pathway. Consistent with this pro-inflammatory signature, in vivo evidence points to a non-redundant role for chemokines and infiltrating monocytes/macrophages in FGF2-driven neovascularization. This review will focus on the cross-talk between FGF2 and the inflammatory response in the modulation of blood vessel growth
Caveolin-1 overexpression in the human embryonal rhabdomyosarcoma RD cells increases tumor growth and metastasis in vivo through a phospho-ERK-dependent signaling pathway
Full text linkCaveolin-1 (Cav-1) represents the principal component of caveolae, flask-shaped invaginations of the plasma membrane controlling different processes like endocytosis, mechanoprotection and signal transduction.
Cav-1 expression and/or function is often dysregulated in cancer, being associated to an increased or decreased tumor cell behavior depending on the cell context. We proposed Cav-1 as a marker of poorly differentiated cells in rhabdomyosarcoma (RMS), a class of childhood soft tissue sarcomas characterized by expression of myogenic markers. In addition, we have further shown that increasing or depleting Cav-1 expression levels in the human embryonal RD cells correlates with an augmented or decreased tumor cell behavior, respectively. In the attempt to further characterize the role of Cav-1 in RMS in vivo, here we demonstrate that injecting subcutaneously Cav-1-overexpressing RD cells in SCID nude mice led to rapid growth of huge RMS tumors in comparison to control mice; in addition, tail vein injection was followed by rapid lung metastasis formation. Ex vitro transplantation of lung metastatic cells followed by re-injection in the tail vein of SCID mice allowed us to isolate two clonal metastatic RD populations (named F1 and F2) characterized by increased ability to disseminate in a shorter time as compared to controls. FACS analyses revealed that both Cav-1 overexpressing RD cells and the metastatic F1-F2 populations exhibited a rapid G1 phase transition, characterized by massive activation of the phosphorylated ERK1/2 pathway. As a result, treatment of these cells with a pharmacological inhibitor of ERK phosphorylation (PD098059) was sufficient to prevent in vitro the increased proliferation and migration associated to the high Cav-1 levels. Overall, these data establish an important connection between the levels of Cav-1 and the activation of the ERK1/2 pathway underlying the augmented cell aggressiveness in RMS cells
Caveolin-1 overexpression accelerates tumor growth and metastasis of embryonal rhabdomyosarcoma
Full text linkCaveolin-1 (Cav-1) is a plasma membrane scaffolding protein that was shown to control the ERK pathway in muscle satellite cells. Oncogenic transformation of satellite cells is responsible of the generation of rhabdomyosarcoma (RMS), a soft tissue tumor affecting childhood and adolescence. We previously reported that Cav-1 is a marker of proliferating RMS cell lines and that its overexpression promotes increased malignancy of RMS cells in vitro and in vivo. Here we show that tail vein injection of the human embryonal RD cells with Cav-1 overexpression (RD Cav-1) into NOD/SCID mice resulted in formation of lung metastasis in about 9 weeks as compared to control cells that did not form metastasis. After performing ex vivo transplantation of lung metastases we isolated one cell population, termed lung metastatic RD1, which injected in mice again gave rise to lung metastases in 5 weeks; from these disseminated lungs we were able to isolate the lung metastatic RD2 cell population. All the distinct cell populations, including RD Cav-1 and lung metastatic RD1 and RD2 clones, retained high Cav-1 expression and showed high phosphorylation levels of ERK1/2, which completely prevented their ability to undergo myogenic differentiation. In addition, lung metastatic RD1 and RD2 clones exhibited an increased migration, adhesion and production of angiogenic stimuli in comparison to non-metastatic control RD and RD Cav-1 lines. Taken together, these data suggest a key role of Cav-1 in promoting both local tumor growth and metastasis of RMS through cooperation of the ERK signalling pathway
Future applications of FGF/FGFR inhibitors in cancer
No full textDeregulation of the fibroblast growth factor (FGF)/FGF receptor (FGFR) network occurs frequently in tumors due to gene amplification, activating mutations, and oncogenic fusions. Thus, the development of FGF/FGFR-targeting therapies is the focus of several basic, preclinical, and clinical studies. Areas covered: This review will recapitulate the status of current FGF/FGFR-targeted drugs. Expert commentary: Non-selective FGF/FGFR inhibitors have been approved for cancer treatment but evidence highlights various complications affecting their use in the clinical practice. It appears mandatory to identify FGF/FGFR alterations and appropriate biomarkers that may predict and monitor response to treatment, to establish the contribution of the FGF/FGFR system to the onset of mechanisms of drug resistance, and to develop effective combinations of FGF/FGFR inhibitors with other targeted therapies
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