RESUMO
The vascular endothelial growth factors (VEGFs) and their cognate receptors (VEGFRs), besides their well-known involvement in physiological angiogenesis/lymphangiogenesis and in diseases associated to pathological vessel formation, play multifaceted functions in the central nervous system (CNS). In addition to shaping brain development, by controlling cerebral vasculogenesis and regulating neurogenesis as well as astrocyte differentiation, the VEGFs/VEGFRs axis exerts essential functions in the adult brain both in physiological and pathological contexts. In this article, after describing the physiological VEGFs/VEGFRs functions in the CNS, we focus on the VEGFs/VEGFRs involvement in neurodegenerative diseases by reviewing the current literature on the rather complex VEGFs/VEGFRs contribution to the pathogenic mechanisms of Alzheimer's (AD) and Parkinson's (PD) diseases. Thereafter, based on the outcome of VEGFs/VEGFRs targeting in animal models of AD and PD, we discuss the factual relevance of pharmacological VEGFs/VEGFRs modulation as a novel and potential disease-modifying approach for these neurodegenerative pathologies. Specific VEGFRs targeting, aimed at selective VEGFR-1 inhibition, while preserving VEGFR-2 signal transduction, appears as a promising strategy to hit the molecular mechanisms underlying AD pathology. Moreover, therapeutic VEGFs-based approaches can be proposed for PD treatment, with the aim of fine-tuning their brain levels to amplify neurotrophic/neuroprotective effects while limiting an excessive impact on vascular permeability.
Assuntos
Doença de Alzheimer , Doença de Parkinson , Animais , Doença de Parkinson/tratamento farmacológico , Doença de Alzheimer/tratamento farmacológico , Receptor 1 de Fatores de Crescimento do Endotélio Vascular , Sistema Nervoso Central , EncéfaloRESUMO
Melanoma resistance to BRAF inhibitors (BRAFi) is often accompanied by a switch from a proliferative to an invasive phenotype. Therefore, the identification of signaling molecules involved in the development of metastatic properties by resistant melanoma cells is of primary importance. We have previously demonstrated that activation of neuropilin-1 (NRP-1) by platelet-derived growth factor (PDGF)-C confers melanoma cells with an invasive behavior similar to that of BRAFi resistant tumors. Aims of the present study were to evaluate the role of PDGF-C/NRP-1 autocrine loop in the acquisition of an invasive and BRAFi-resistant phenotype by melanoma cells and the effect of its inhibition on drug resistance and extracellular matrix (ECM) invasion. Furthermore, we investigated whether PDGF-C serum levels were differentially modulated by drug treatment in metastatic melanoma patients responsive or refractory to BRAFi as single agents or in combination with MEK inhibitors (MEKi). The results indicated that human melanoma cells resistant to BRAFi express higher levels of PDGF-C and NRP-1 as compared to their susceptible counterparts. Overexpression occurs early during development of drug resistance and contributes to the invasive properties of resistant cells. Accordingly, silencing of NRP-1 or PDGF-C reduces tumor cell invasiveness. Analysis of PDGF-C in the serum collected from patients treated with BRAFi or BRAFi+MEKi, showed that in responders PDGF-C levels decrease after treatment and raise again at tumor progression. Conversely, in non-responders treatment does not affect PDGF-C serum levels. Thus, blockade of NRP-1 activation by PDGF-C might represent a new therapeutic approach to counteract the invasiveness of BRAFi-resistant melanoma.
Assuntos
Melanoma , Proteínas Proto-Oncogênicas B-raf , Humanos , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas B-raf/metabolismo , Neuropilina-1/uso terapêutico , Resistencia a Medicamentos Antineoplásicos , Melanoma/genética , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Fator de Crescimento Derivado de Plaquetas/farmacologia , Linhagem Celular TumoralRESUMO
The immune checkpoint cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) is an inhibitory regulator of T-cell mediated responses that has been investigated as target of monoclonal antibodies (mAbs) for cancer immunotherapy. The anti-CTLA-4 mAb ipilimumab represents the first immune checkpoint inhibitor that significantly improved overall survival in patients with unresectable/metastatic melanoma. The subsequent approved indications (often in the first-line setting) for melanoma and other advanced/metastatic solid tumors always require ipilimumab combination with nivolumab, an anti-programmed cell death protein 1 (PD-1) mAb. However, the improved clinical efficacy of the mAb combination is associated with increased immune-related adverse events, which might require treatment discontinuation even in responding patients. This drawback is expected to be overcome by the recent development of anti-CTLA-4 probodies proteolitycally activated in the tumor microenvironment and bispecific molecules targeting both CTLA-4 and PD-1, whose co-expression is characteristic of tumor-infiltrating T cells. These molecules would preferentially stimulate immune responses against the tumor, reducing toxicity toward normal tissues.
Assuntos
Antineoplásicos Imunológicos/uso terapêutico , Antígeno CTLA-4/antagonistas & inibidores , Ipilimumab/uso terapêutico , Neoplasias/tratamento farmacológico , Microambiente Tumoral/efeitos dos fármacos , Animais , Anticorpos Biespecíficos/imunologia , Antineoplásicos Imunológicos/efeitos adversos , Humanos , Imunoterapia/efeitos adversos , Ipilimumab/efeitos adversos , Neoplasias/imunologia , Microambiente Tumoral/imunologiaRESUMO
The vascular endothelial growth factor receptor-1 (VEGFR-1) is a tyrosine kinase receptor frequently expressed in melanoma. Its activation by VEGF-A or placental growth factor (PlGF) promotes tumour cell survival, migration and invasiveness. Moreover, VEGFR-1 stimulation contributes to pathological angiogenesis and induces recruitment of tumour-associated macrophages. Since melanoma acquired resistance to BRAF inhibitors (BRAFi) has been associated with activation of pro-angiogenic pathways, we have investigated VEGFR-1 involvement in vemurafenib resistance. Results indicate that human melanoma cells rendered resistant to vemurafenib secrete greater amounts of VEGF-A and express higher VEGFR-1 levels compared with their BRAFi-sensitive counterparts. Transient VEGFR-1 silencing in susceptible melanoma cells delays resistance development, whereas in resistant cells it increases sensitivity to the BRAFi. Consistently, enforced VEGFR-1 expression, by stable gene transfection in receptor-negative melanoma cells, markedly reduces sensitivity to vemurafenib. Moreover, melanoma cells expressing VEGFR-1 are more invasive than VEGFR-1 deficient cells and receptor blockade by a specific monoclonal antibody (D16F7 mAb) reduces extracellular matrix invasion triggered by VEGF-A and PlGF. These data suggest that VEGFR-1 up-regulation might contribute to melanoma progression and spreading after acquisition of a drug-resistant phenotype. Thus, VEGFR-1 inhibition with D16F7 mAb might be a suitable adjunct therapy for VEGFR-1 positive tumours with acquired resistance to vemurafenib.
Assuntos
Resistencia a Medicamentos Antineoplásicos , Melanoma/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Neoplasias Cutâneas/tratamento farmacológico , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Vemurafenib/uso terapêutico , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Matriz Extracelular/efeitos dos fármacos , Matriz Extracelular/metabolismo , Inativação Gênica/efeitos dos fármacos , Humanos , Melanoma/patologia , Invasividade Neoplásica , Fenótipo , Fator de Crescimento Placentário/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Neoplasias Cutâneas/patologia , Fator A de Crescimento do Endotélio Vascular/metabolismo , Vemurafenib/farmacologiaRESUMO
The vascular endothelial growth factor receptor-1 (VEGFR-1) is a membrane receptor for VEGF-A, placenta growth factor (PlGF) and VEGF-B that plays a crucial role in melanoma invasiveness, vasculogenic mimicry and tumor-associated angiogenesis. Furthermore, activation of VEGFR-1 is involved in the mobilization of myeloid progenitors from the bone marrow that infiltrate the tumor. Myeloid-derived suppressor cells and tumor-associated macrophages have been involved in tumor progression and resistance to cancer treatment with immune checkpoint inhibitors (ICIs). We have recently demonstrated that the anti-VEGFR-1 monoclonal antibody (mAb) D16F7 developed in our laboratories is able to inhibit melanoma growth in preclinical in vivo models and to reduce monocyte/macrophage progenitor mobilization and tumor infiltration by myeloid cells. Aim of the study was to investigate whether the anti-VEGFR-1 mAb D16F7 affects the activity of protumoral M2 macrophages in vitro in response to PlGF and inhibits the recruitment of these cells to the melanoma site in vivo. Finally, we tested whether, through its multi-targeted action, D16F7 mAb might increase the efficacy of ICIs against melanoma. The results indicated that VEGFR-1 expression is up-regulated in human activated M2 macrophages compared to activated M1 cells and exposure to the D16F7 mAb decreases in vitro chemotaxis of activated M2 macrophages. In vivo treatment with the anti-VEGFR-1 mAb D16F7 of B6D2F1 mice injected with syngeneic B16F10 melanoma cells resulted in tumor growth inhibition associated with the modification of tumor microenvironment that involves a decrease of melanoma infiltration by M2 macrophages and PD-1+ and FoxP3+ cells. These alterations result in increased M1/M2 and CD8+/FoxP3+ ratios, which favor an antitumor and immunostimulating milieu. Accordingly, D16F7 mAb increased the antitumor activity of the ICIs anti-CTLA-4 and anti-PD-1 mAbs. Overall, these data reinforce the role of VEGFR-1-mediated-signalling as a valid target for reducing tumor infiltration by protumoral macrophages and for improving the efficacy of immunotherapy with ICIs.
Assuntos
Anticorpos Monoclonais/farmacologia , Antineoplásicos Imunológicos/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Inibidores de Checkpoint Imunológico/farmacologia , Melanoma/tratamento farmacológico , Neoplasias Cutâneas/tratamento farmacológico , Macrófagos Associados a Tumor/efeitos dos fármacos , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Animais , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Linhagem Celular Tumoral , Humanos , Linfócitos do Interstício Tumoral/efeitos dos fármacos , Linfócitos do Interstício Tumoral/imunologia , Linfócitos do Interstício Tumoral/metabolismo , Ativação de Macrófagos/efeitos dos fármacos , Masculino , Melanoma/imunologia , Melanoma/metabolismo , Melanoma Experimental/tratamento farmacológico , Melanoma Experimental/imunologia , Melanoma Experimental/metabolismo , Camundongos , Neoplasias Cutâneas/imunologia , Neoplasias Cutâneas/metabolismo , Microambiente Tumoral , Macrófagos Associados a Tumor/imunologia , Macrófagos Associados a Tumor/metabolismo , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/imunologia , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/metabolismoRESUMO
The vascular endothelial growth factor (VEGF) family members, VEGF-A, placenta growth factor (PlGF), and to a lesser extent VEGF-B, play an essential role in tumor-associated angiogenesis, tissue infiltration, and metastasis formation. Although VEGF-A can activate both VEGFR-1 and VEGFR-2 membrane receptors, PlGF and VEGF-B exclusively interact with VEGFR-1. Differently from VEGFR-2, which is involved both in physiological and pathological angiogenesis, in the adult VEGFR-1 is required only for pathological angiogenesis. Besides this role in tumor endothelium, ligand-mediated stimulation of VEGFR-1 expressed in tumor cells may directly induce cell chemotaxis and extracellular matrix invasion. Furthermore, VEGFR-1 activation in myeloid progenitors and tumor-associated macrophages favors cancer immune escape through the release of immunosuppressive cytokines. These properties have prompted a number of preclinical and clinical studies to analyze VEGFR-1 involvement in the metastatic process. The aim of the present review is to highlight the contribution of VEGFs/VEGFR-1 signaling in the progression of different tumor types and to provide an overview of the therapeutic approaches targeting VEGFR-1 currently under investigation.
Assuntos
Neoplasias/metabolismo , Neoplasias/patologia , Transdução de Sinais , Fator A de Crescimento do Endotélio Vascular/metabolismo , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Animais , Humanos , Invasividade Neoplásica , Metástase Neoplásica , Neoplasias/terapiaRESUMO
The glioblastoma (GB) microenvironment includes cells of the innate immune system identified as glioma-associated microglia/macrophages (GAMs) that are still poorly characterized. A potential role on the mechanisms regulating GAM activity might be played by the endoplasmic reticulum protein ERp57/PDIA3 (protein disulfide-isomerase A3), the modulation of which has been reported in a variety of cancers. Moreover, by using The Cancer Genome Atlas database, we found that overexpression of PDIA3 correlated with about 55% reduction of overall survival of glioma patients. Therefore, we analyzed the expression of ERp57/PDIA3 using specimens obtained after surgery from 18 GB patients. Immunohistochemical analysis of tumor samples revealed ERp57/PDIA3 expression in GB cells as well as in GAMs. The ERp57/PDIA3 levels were higher in GAMs than in the microglia present in the surrounding parenchyma. Therefore, we studied the role of PDIA3 modulation in microglia-glioma interaction, based on the ability of conditioned media collected from human GB cells to induce the activation of microglial cells. The results indicated that reduced PDIA3 expression/activity in GB cells significantly limited the microglia pro-tumor polarization towards the M2 phenotype and the production of pro-inflammatory factors. Our data support a role of PDIA3 expression in GB-mediated protumor activation of microglia.
Assuntos
Neoplasias Encefálicas/patologia , Glioblastoma/patologia , Ativação de Macrófagos/genética , Microglia/fisiologia , Isomerases de Dissulfetos de Proteínas/genética , Microambiente Tumoral/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Encefálicas/genética , Células Cultivadas , Estudos de Coortes , Progressão da Doença , Feminino , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Glioblastoma/genética , Humanos , Macrófagos/metabolismo , Macrófagos/patologia , Macrófagos/fisiologia , Masculino , Microglia/metabolismo , Microglia/patologia , Pessoa de Meia-Idade , Isomerases de Dissulfetos de Proteínas/metabolismoRESUMO
Therapy of multiple sclerosis (MS) with disease-modifying agents such as natalizumab or fingolimod has been associated with the development of cutaneous melanoma. Here we briefly revise literature data and report of a case of a 48-year old woman who developed a melanoma and several atypical naevi after sub sequential treatment with natalizumab (1 year) and fingolimod (7 years). By immunohistochemistry we observed the presence of T cells and leukocyte infiltration as well as of vascular endothelial growth factor (VEGF)-A expression in the patient melanoma biopsy. Then, we analyzed proliferation, migration and VEGF-A expression in three melanoma cell lines and found out that both natalizumab and fingolimod inhibited tumor cell proliferation but promoted or blocked cell migration depending on the cell line examined. VEGF-A secretion was augmented in one melanoma cell line only after fingolimod treatment. In conclusion, our in vitro data do not support the hypothesis of a direct action of natalizumab or fingolimod on melanoma progression but acting on the tumor microenvironment these treatments could indirectly favor melanoma evolution.
Assuntos
Antirreumáticos/uso terapêutico , Melanoma/diagnóstico , Melanoma/etiologia , Esclerose Múltipla/complicações , Esclerose Múltipla/terapia , Antirreumáticos/efeitos adversos , Biomarcadores , Biópsia , Suscetibilidade a Doenças , Feminino , Cloridrato de Fingolimode/efeitos adversos , Cloridrato de Fingolimode/uso terapêutico , Humanos , Imuno-Histoquímica , Imunossupressores/efeitos adversos , Imunossupressores/uso terapêutico , Melanoma/metabolismo , Melanoma/terapia , Pessoa de Meia-Idade , Esclerose Múltipla/diagnóstico , Natalizumab/efeitos adversos , Natalizumab/uso terapêutico , Neoplasias Cutâneas/diagnóstico , Neoplasias Cutâneas/etiologia , Neoplasias Cutâneas/terapia , Fator A de Crescimento do Endotélio Vascular/metabolismo , Melanoma Maligno CutâneoRESUMO
The vascular endothelial growth factor (VEGF) receptor-1 (VEGFR-1) is a tyrosine kinase receptor that does not play a relevant role in physiologic angiogenesis in adults, whereas it is important in tumor angiogenesis. In high-grade glioma VEGFR-1 expression by tumor endothelium and neoplastic cells contributes to the aggressive phenotype. We recently generated an anti-VEGFR-1 monoclonal antibody (D16F7 mAb) characterized by a novel mechanism of action, since it hampers receptor activation without interfering with ligand binding. The mAb is able to inhibit chemotaxis and extracellular matrix invasion of glioma cells in vitro stimulated by VEGF-A and by the VEGFR-1-selective ligand placental growth factor (PlGF). In this study, we have investigated the influence of D16F7 on glioma growth and angiogenesis in vivo using C6 glioma cells transfected with the human VEGFR-1. D16F7 was able to inhibit receptor activation and migration and extracellular matrix invasion of C6 cells overexpressing the receptor in response to PlGF and VEGF-A. In nude mice, treatment with 10 and 20 mg/kg D16F7 as a single agent was well tolerated and significantly inhibited glioma growth (P < 0.001). Strikingly, in an intracranial orthotopic model, mice dosed with 20 mg/kg D16F7 demonstrated a 65% increase in median survival time compared with vehicle-treated controls (P < 0.001) with a high percentage of long-term survivors (46%). These effects were associated with glioma cell apoptosis and decreased tumor-associated vessel formation. Overall, these results highlight the therapeutic potential of D16F7 in glioma treatment, deserving further investigation after a humanization process as single agent or in combination therapies.
Assuntos
Inibidores da Angiogênese/farmacologia , Anticorpos Monoclonais/farmacologia , Proliferação de Células/efeitos dos fármacos , Glioma/tratamento farmacológico , Neovascularização Patológica/tratamento farmacológico , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Matriz Extracelular/efeitos dos fármacos , Matriz Extracelular/metabolismo , Matriz Extracelular/patologia , Glioma/metabolismo , Glioma/patologia , Humanos , Masculino , Camundongos , Camundongos Nus , Neovascularização Patológica/metabolismo , Neovascularização Patológica/patologia , Fator de Crescimento Placentário/metabolismo , Ratos , Fator A de Crescimento do Endotélio Vascular/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The vascular endothelial growth factor receptor-1 (VEGFR-1) is a tyrosine kinase receptor for VEGF-A, VEGF-B, and placental growth factor (PlGF) ligands that is expressed in endothelial, myelomonocytic and tumor cells. VEGF-B and PlGF exclusively bind to VEGFR-1, whereas VEGF-A also binds to VEGFR-2. At variance with VEGFR-2, VEGFR-1 does not play a relevant role in physiological angiogenesis in the adult, while it is important in tumor-associated angiogenesis. VEGFR-1 and PlGF are expressed in a variety of tumors, promote invasiveness and contribute to resistance to anti-VEGF-A therapy. The currently approved antiangiogenic therapies for the treatment of a variety of solid tumors hamper VEGF-A signaling mediated by both VEGFR-2 and VEGFR-1 [i.e., the monoclonal antibody (mAb) anti-VEGF-A bevacizumab, the chimeric molecule aflibercept and several small molecule tyrosine kinase inhibitors] or exclusively by VEGFR-2 (i.e., the mAb anti-VEGFR-2 ramucirumab). However, molecules that interfere with VEGF-A/VEGFR-2 signaling determine severe adverse effects due to inhibition of physiological angiogenesis and their efficacy is hampered by tumor infiltration of protumoral myeloid cells. Blockade of VEGFR-1 may exert anti-tumor activity by multiple mechanisms: a) inhibition of tumor-associated angiogenesis; b) reduction of myeloid progenitor mobilization and tumor infiltration by VEGFR-1 expressing M2 macrophages, which contribute to tumor progression and spreading; c) inhibition of invasiveness, vasculogenic mimicry and survival of VEGFR-1 positive tumor cells. As a consequence of these properties, molecules targeting VEGFR-1 are expected to produce less adverse effects and to counteract resistance towards anti-VEGF-A therapies. More interestingly, selective VEGFR-1 inhibition might enhance the efficacy of immunotherapy with immune checkpoint inhibitors. In this review, we will examine the experimental evidence available so far that supports targeting VEGFR-1 signal transduction pathway for cancer treatment by competitive inhibitors that prevent growth factor interaction with the receptor and non-competitive inhibitors that hamper receptor activation without affecting ligand binding.
Assuntos
Neoplasias/tratamento farmacológico , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Animais , Antineoplásicos/uso terapêutico , Humanos , Células Mieloides/fisiologia , Neoplasias/metabolismo , Microambiente Tumoral/efeitos dos fármacos , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/fisiologiaRESUMO
In recent years, accumulating evidence from preclinical and clinical studies consistently indicated that physical activity/exercise plays a crucial role in reducing the incidence and recurrence of various malignancies, by exerting a beneficial modulation of cancer hallmarks. Moreover, physical activity is suggested to attenuate certain adverse effects of anticancer therapy, including the reduction of cardiovascular toxicity and symptoms related to depression and anxiety, among others, while preserving muscular strength. In the case of melanoma, the relationship with physical activity has been critically debated. Historically, several cohort studies and meta-analyses reported a positive association between physical activity/exercise and melanoma risk. This association was primarily attributed to outdoor activities that may expose the skin to UV radiation, a well-known risk factor for melanocyte transformation. However, more recent evidence does not support such association and recognizes physical activity/exercise role in both melanoma prevention and progression. Nevertheless, sun protection is recommended during outdoor training to minimize UV radiation exposure. This narrative review summarizes preclinical and clinical data about physical activity effects on melanoma hallmarks. Specifically, experimental evidence is reported concerning (i) invasion and metastasis, (ii) reprogramming of energy metabolism, (iii) angiogenesis, (iv) resistance to cell death, (v) evasion from immune destruction, and (vi) tumor-promoting inflammation.
RESUMO
BACKGROUND: Circulating cytokines can represent non-invasive biomarkers to improve prediction of clinical outcomes of cancer patients. Here, plasma levels of IL-8, CCL4, osteopontin, LIF and BDNF were determined at baseline (T0), after 2 months of therapy (T2) and, when feasible, at progression (TP), in 70 melanoma patients treated with BRAF and MEK inhibitors. The association of baseline cytokine levels with clinical response, progression-free survival (PFS) and overall survival (OS) was evaluated. METHODS: Cytokine concentrations were measured using the xMAP technology. Their ability to discriminate between responding (Rs) and non-responding (NRs) patients was assessed by Receiver Operating Characteristics analysis. PFS and OS were estimated with the Kaplan-Meier method. The Cox proportional hazard model was used in the univariate and multivariate analyses to estimate crude and adjusted hazard ratios with 95% confidence intervals. RESULTS: CCL4 and LIF were undetectable in the majority of samples. The median osteopontin concentration at T0 and T2 was significantly higher in NRs than in Rs. The median T0 and T2 values of IL-8 were also higher in NRs than in Rs, although the statistical significance was not reached. No differences were detected for BDNF. In 39 Rs with matched T0, T2, and TP samples, osteopontin and IL-8 significantly decreased from T0 to T2 and rose again at TP, while BDNF levels remained unchanged. In NRs, none of the cytokines showed a significant decrease at T2. Only osteopontin demonstrated a good ability to discriminate between Rs and NRs. A high IL-8 T0 level was associated with significantly shorter PFS and OS and higher risk of progression and mortality, and remained an independent negative prognostic factor for OS in multivariate analysis. An elevated osteopontin T0 concentration was also significantly associated with worse OS and increased risk of death. Patients with high IL-8 and high osteopontin showed the lowest PFS and OS, and in multivariate analysis this cytokine combination remained independently associated with a three- to six-fold increased risk of mortality. CONCLUSION: Circulating IL-8 and osteopontin appear useful biomarkers to refine prognosis evaluation of patients undergoing targeted therapy, and deserve attention as potential targets to improve its clinical efficacy.
Assuntos
Biomarcadores Tumorais , Interleucina-8 , Melanoma , Osteopontina , Humanos , Osteopontina/sangue , Interleucina-8/sangue , Masculino , Feminino , Melanoma/tratamento farmacológico , Melanoma/sangue , Melanoma/mortalidade , Melanoma/patologia , Pessoa de Meia-Idade , Biomarcadores Tumorais/sangue , Idoso , Adulto , Terapia de Alvo Molecular , Resultado do Tratamento , Idoso de 80 Anos ou maisRESUMO
The interaction of glucocorticoid-induced tumor necrosis factor receptor-family related (GITR) protein with its ligand (GITRL) modulates different functions, including immune/inflammatory response. These effects are consequent to intracellular signals activated by both GITR and GITRL. Previous results have suggested that lack of GITR expression in GITR(-/-) mice decreases the number of leukocytes within inflamed tissues. We performed experiments to analyze whether the GITRL/GITR system modulates leukocyte adhesion and extravasation. For that purpose, we first evaluated the capability of murine splenocytes to adhere to endothelial cells (EC). Our results indicated that adhesion of GITR(-/-) splenocytes to EC was reduced as compared with wild-type cells, suggesting that GITR plays a role in adhesion and that this effect may be due to GITRL-GITR interaction. Moreover, adhesion was increased when EC were pretreated with an agonist GITR-Fc fusion protein, thus indicating that triggering of GITRL plays a role in adhesion by EC regulation. In a human in vitro model, the adhesion to human EC of HL-60 cells differentiated toward the monocytic lineage was increased by EC pretreatment with agonist GITR-Fc. Conversely, antagonistic anti-GITR and anti-GITRL Ab decreased adhesion, thus further indicating that GITRL triggering increases the EC capability to support leukocyte adhesion. EC treatment with GITR-Fc favored extravasation, as demonstrated by a transmigration assay. Notably, GITRL triggering increased intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) expression and anti-ICAM-1 and anti-VCAM-1 Abs reversed GITR-Fc effects. Our study demonstrates that GITRL triggering in EC increases leukocyte adhesion and transmigration, suggesting new anti-inflammatory therapeutic approaches based on inhibition of GITRL-GITR interaction.
Assuntos
Adesão Celular/fisiologia , Proteína Relacionada a TNFR Induzida por Glucocorticoide/biossíntese , Molécula 1 de Adesão Intercelular/biossíntese , Leucócitos/fisiologia , Fatores de Necrose Tumoral/biossíntese , Regulação para Cima/fisiologia , Molécula 1 de Adesão de Célula Vascular/biossíntese , Animais , Linhagem Celular Transformada , Proteína Relacionada a TNFR Induzida por Glucocorticoide/agonistas , Proteína Relacionada a TNFR Induzida por Glucocorticoide/metabolismo , Células HL-60 , Humanos , Leucócitos/metabolismo , Ligantes , Camundongos , Camundongos Knockout , Fatores de Necrose Tumoral/agonistas , Fatores de Necrose Tumoral/metabolismoRESUMO
The immunoproteasome is a specialized form of proteasome equipped with modified catalytic subunits that was initially discovered to play a pivotal role in MHC class I antigen processing and immune system modulation. However, over the last years, this proteolytic complex has been uncovered to serve additional functions unrelated to antigen presentation. Accordingly, it has been proposed that immunoproteasome synergizes with canonical proteasome in different cell types of the nervous system, regulating neurotransmission, metabolic pathways and adaptation of the cells to redox or inflammatory insults. Hence, studying the alterations of immunoproteasome expression and activity is gaining research interest to define the dynamics of neuroinflammation as well as the early and late molecular events that are likely involved in the pathogenesis of a variety of neurological disorders. Furthermore, these novel functions foster the perspective of immunoproteasome as a potential therapeutic target for neurodegeneration. In this review, we provide a brain and retina-wide overview, trying to correlate present knowledge on structure-function relationships of immunoproteasome with the variety of observed neuro-modulatory functions.
Assuntos
Apresentação de Antígeno , Complexo de Endopeptidases do Proteassoma , Humanos , Complexo de Endopeptidases do Proteassoma/metabolismo , Transmissão Sináptica , Encéfalo/metabolismoRESUMO
Antibody-drug conjugates (ADCs) constitute a relatively new group of anticancer agents, whose first appearance took place about two decades ago, but a renewed interest occurred in recent years, following the success of anti-cancer immunotherapy with monoclonal antibodies. Indeed, an ADC combines the selectivity of a monoclonal antibody with the cell killing properties of a chemotherapeutic agent (payload), joined together through an appropriate linker. The antibody moiety targets a specific cell surface antigen expressed by tumor cells and/or cells of the tumor microenvironment and acts as a carrier that delivers the cytotoxic payload within the tumor mass. Despite advantages in terms of selectivity and potency, the development of ADCs is not devoid of challenges, due to: i) low tumor selectivity when the target antigens are not exclusively expressed by cancer cells; ii) premature release of the cytotoxic drug into the bloodstream as a consequence of linker instability; iii) development of tumor resistance mechanisms to the payload. All these factors may result in lack of efficacy and/or in no safety improvement compared to unconjugated cytotoxic agents. Nevertheless, the development of antibodies engineered to remain inert until activated in the tumor (e.g., antibodies activated proteolytically after internalization or by the acidic conditions of the tumor microenvironment) together with the discovery of innovative targets and cytotoxic or immunomodulatory payloads, have allowed the design of next-generation ADCs that are expected to possess improved therapeutic properties. This review provides an overview of approved ADCs, with related advantages and limitations, and of novel targets exploited by ADCs that are presently under clinical investigation.
Assuntos
Antineoplásicos , Imunoconjugados , Neoplasias , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais/uso terapêutico , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Humanos , Imunoconjugados/farmacologia , Imunoconjugados/uso terapêutico , Microambiente TumoralRESUMO
Placenta growth factor (PlGF) is a member of the vascular endothelial growth factor (VEGF) family involved in tumor-associated angiogenesis and melanoma invasion of the extra-cellular matrix (ECM) through activation of membrane VEGF receptor 1 (VEGFR-1). A soluble VEGFR-1 (sVEGFR-1) form is released in the ECM, where it sequesters proangiogenic factors and stimulates endothelial or tumor cell adhesion and chemotaxis through interaction with α5ß1 integrin. The anti-VEGFR-1 monoclonal antibody (D16F7 mAb) inhibits VEGF-A or PlGF-mediated signal transduction without affecting ligand interaction, thus preserving sVEGFR-1 decoy function. The aim of this study was to investigate whether D16F7 mAb hampers melanoma spread by in vitro analysis of cell adhesion to sVEGFR-1, ECM invasion, transmigration through an endothelial cell monolayer and in vivo evaluation of tumor infiltrative potential in a syngeneic murine model. Results indicate that D16F7 mAb significantly inhibits melanoma adhesion to sVEGFR-1 and ECM invasion, as well as transmigration in response to PlGF. Moreover, treatment of melanoma-bearing mice with the anti-VEGFR-1 mAb not only inhibits tumor growth but also induces a significant reduction in bone infiltration associated with a decrease in PlGF-positive melanoma cells. Furthermore, D16F7 mAb reduces PlGF production by melanoma cells. Therefore, blockade of PLGF/VEGFR-1 signaling represents a suitable strategy to counteract the metastatic potential of melanoma.
RESUMO
Neuropilin-1 (NRP-1) is a semaphorin receptor involved in neuron guidance, and a co-receptor for selected isoforms of the vascular endothelial growth factor (VEGF) family. NRP-1 binding to several VEGF-A isoforms promotes growth factor interaction with VEGF receptor (VEGFR)-2, increasing receptor phosphorylation. Additionally, NRP-1 directly interacts with VEGFR-1, but this interaction competes with NRP-1 binding to VEGF-A165 and does not enhance VEGFR-1 activation. In this work, we investigated in detail the role of NRP-1 interaction with the soluble isoform of VEGFR-1 (sVEGFR-1) in angiogenesis. sVEGFR-1 acts both as a decoy receptor for VEGFs and as an extracellular matrix protein directly binding to α5ß1 integrin on endothelial cells. By combining cell adhesion assays and surface plasmon resonance experiments on purified proteins, we found that sVEGFR-1/NRP-1 interaction is required both for α5ß1 integrin binding to sVEGFR-1 and for endothelial cell adhesion to a sVEGFR-1-containing matrix. We also found that a previously reported anti-angiogenic peptide (Flt2-11 ), which maps in the second VEGFR-1 Ig-like domain, specifically binds NRP-1 and inhibits NRP-1/sVEGFR-1 interaction, a process that likely contributes to its anti-angiogenic activity. In view of potential translational applications, we developed a five-residue-long peptide, derived from Flt2-11 , which has the same ability as the parent Flt2-11 peptide to inhibit cell adhesion to, and migration towards, sVEGFR-1. Therefore, the Flt2-5 peptide represents a potential anti-angiogenic compound per se, as well as an attractive lead for the development of novel angiogenesis inhibitors acting with a different mechanism with respect to currently used therapeutics, which interfere with VEGF-A165 binding.
Assuntos
Adesão Celular/genética , Neuropilina-1/genética , Fator A de Crescimento do Endotélio Vascular/genética , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/genética , Movimento Celular/genética , Células Endoteliais/metabolismo , Humanos , Neovascularização Patológica/genética , Neovascularização Fisiológica/genética , Neurônios/metabolismo , Fosforilação/genética , Ligação Proteica/genética , Transdução de Sinais/genética , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/genéticaRESUMO
Despite the significant improvements in advanced melanoma therapy, there is still a pressing need for biomarkers that can predict patient response and prognosis, and therefore support rational treatment decisions. Here, we investigated whether circulating miRNAs could be biomarkers of clinical outcomes in patients treated with targeted therapy. Using next-generation sequencing, we profiled plasma miRNAs at baseline and at progression in patients treated with BRAF inhibitors (BRAFi) or BRAFi + MEKi. Selected miRNAs associated with response to therapy were subjected to validation by real-time quantitative RT-PCR. Receiver Operating Characteristics (ROC), Kaplan-Meier and univariate and multivariate Cox regression analyses were performed on the validated miR-1246 and miR-485-3p baseline levels. The median baseline levels of miR-1246 and miR-485-3p were significantly higher and lower, respectively, in the group of patients not responding to therapy (NRs) as compared with the group of responding patients (Rs). In Rs, a trend toward an increase in miR-1246 and a decrease in miR-485-3p was observed at progression. Baseline miR-1246 level and the miR-1246/miR-485-3p ratio showed a good ability to discriminate between Rs and NRs. Poorer PFS and OS were observed in patients with unfavorable levels of at least one miRNA. In multivariate analysis, a low level of miR-485-3p and a high miR-1246/miR-485-3p ratio remained independent negative prognostic factors for PFS, while a high miR-1246/miR-485-3p ratio was associated with an increased risk of mortality, although statistical significance was not reached. Evaluation of miR-1246 and miR-485-3p baseline plasma levels might help clinicians to identify melanoma patients most likely to be unresponsive to targeted therapy or at higher risk for short-term PFS and mortality, thus improving their management.
RESUMO
BACKGROUND: Diabetic retinopathy (DR) is a microvascular complication of diabetes with a heavy impact on the quality of life of subjects and with a dramatic burden for health and economic systems on a global scale. Although the pathogenesis of DR is largely unknown, several preclinical data have pointed out to a main role of Muller glia (MG), a cell type which spans across the retina layers providing nourishment and support for Retina Ganglion Cells (RGCs), in sensing hyper-glycemia and in acquiring a pro-inflammatory polarization in response to this insult. RESULTS: By using a validated experimental model of DR in vitro, rMC1 cells challenged with high glucose, we uncovered the induction of an early (within minutes) and atypical Nuclear Factor-kB (NF-kB) signalling pathway regulated by a calcium-dependent calmodulin kinase II (CamKII)-proteasome axis. Phosphorylation of proteasome subunit Rpt6 (at Serine 120) by CamKII stimulated the accelerated turnover of IkBα (i.e., the natural inhibitor of p65-50 transcription factor), regardless of the phosphorylation at Serine 32 which labels canonical NF-kB signalling. This event allowed the p65-p50 heterodimer to migrate into the nucleus and to induce transcription of IL-8, Il-1ß and MCP-1. Pharmacological inhibition of CamKII as well as proteasome inhibition stopped this pro-inflammatory program, whereas introduction of a Rpt6 phospho-dead mutant (Rpt6-S120A) stimulated a paradoxical effect on NF-kB probably through the activation of a compensatory mechanism which may involve phosphorylation of 20S α4 subunit. CONCLUSIONS: This study introduces a novel pathway of MG activation by high glucose and casts some light on the biological relevance of proteasome post-translational modifications in modulating pathways regulated through targeted proteolysis.
RESUMO
BACKGROUND: Neuropathic pain is a clinically relevant adverse effect of several anticancer drugs that markedly impairs patients' quality of life and frequently leads to dose reduction or therapy discontinuation. The poor knowledge about the mechanisms involved in neuropathy development and pain chronicization, and the lack of effective therapies, make treatment of chemotherapy-induced neuropathic pain an unmet medical need. In this context, the vascular endothelial growth factor A (VEGF-A) has emerged as a candidate neuropathy hallmark and its decrease has been related to pain relief. In the present study, we have investigated the role of VEGF-A and its receptors, VEGFR-1 and VEGFR-2, in pain signalling and in chemotherapy-induced neuropathy establishment as well as the therapeutic potential of receptor blockade in the management of pain. METHODS: Behavioural and electrophysiological analyses were performed in an in vivo murine model, by using selective receptor agonists, blocking monoclonal antibodies or siRNA-mediated silencing of VEGF-A and VEGFRs. Expression of VEGF-A and VEGFR-1 in astrocytes and neurons was detected by immunofluorescence staining and confocal microscopy analysis. RESULTS: In mice, the intrathecal infusion of VEGF-A (VEGF165 isoforms) induced a dose-dependent noxious hypersensitivity and this effect was mediated by VEGFR-1. Consistently, electrophysiological studies indicated that VEGF-A strongly stimulated the spinal nociceptive neurons activity through VEGFR-1. In the dorsal horn of the spinal cord of animals affected by oxaliplatin-induced neuropathy, VEGF-A expression was increased in astrocytes while VEGFR-1 was mainly detected in neurons, suggesting a VEGF-A/VEGFR-1-mediated astrocyte-neuron cross-talk in neuropathic pain pathophysiology. Accordingly, the selective knockdown of astrocytic VEGF-A by intraspinal injection of shRNAmir blocked the development of oxaliplatin-induced neuropathic hyperalgesia and allodynia. Interestingly, both intrathecal and systemic administration of the novel anti-VEGFR-1 monoclonal antibody D16F7, endowed with anti-angiogenic and antitumor properties, reverted oxaliplatin-induced neuropathic pain. Besides, D16F7 effectively relieved hypersensitivity induced by other neurotoxic chemotherapeutic agents, such as paclitaxel and vincristine. CONCLUSIONS: These data strongly support the role of the VEGF-A/VEGFR-1 system in mediating chemotherapy-induced neuropathic pain at the central nervous system level. Thus, treatment with the anti-VEGFR-1 mAb D16F7, besides exerting antitumor activity, might result in the additional advantage of attenuating neuropathic pain when combined with neurotoxic anticancer agents.