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A retrospective observational study utilising cancer incidence data from a population-based registry investigated determinants affecting primary liver cancer survival in a southern Italian region with high hepatitis viral infection rates and obesity prevalence. Among 2687 patients diagnosed between 2006 and 2019 (65.3% male), a flexible hazard-based regression model revealed factors influencing 5-year survival rates. High deprivation levels [HR = 1.41 (95%CI = 1.15-1.76); p < 0.001], poor access to care [HR = 1.99 (95%IC = 1.70-2.35); p < 0.0001], age between 65 and 75 [HR = 1.48 (95%IC = 1.09-2.01); p < 0.05] or >75 [HR = 2.21 (95%CI = 1.62-3.01); p < 0.0001] and residing in non-urban areas [HR = 1.35 (95%CI = 1.08-1.69); p < 0.01] were associated with poorer survival estimates. While deprivation appeared to be a risk factor for primary liver cancer patients residing within the urban area, the geographic distance from specialised treatment centres emerged as a potential determinant of lower survival estimates for residents in the non-urban areas. After balancing the groups of easy and poor access to care using a propensity score approach, poor access to care and a lower socioeconomic status resulted in potentially having a negative impact on primary liver cancer survival, particularly among urban residents. We emphasise the need to interoperate cancer registries with other data sources and to deploy innovative digital solutions to improve cancer prevention.
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Background: Autism spectrum disorder (ASD) diagnoses have rapidly increased globally. Both environmental and genetic factors appear to contribute to the development of ASD. Several studies have shown a potential association between prenatal or postnatal pesticide exposure and the risk of developing ASD. Methods: We reviewed the available literature concerning the relationship between early life exposure to pesticides used in agriculture, such as organochlorines, organophosphates and pyrethroids, and ASD onset in childhood. We searched on Medline and Scopus for cohort or case-control studies published in English from 1977 to 2020. Results: A total of seven articles were selected for the review. We found a remarkable association between the maternal exposure to pyrethroid, as well as the exposure to organophosphate during pregnancy or in the first years of childhood, and the risk of ASD onset. This association was found to be less evident with organochlorine pesticides. Pregnancy seems to be the time when pesticide exposure appears to have the greatest impact on the onset of ASD in children. Conclusions: Among the different environmental pollutants, pesticides should be considered as emerging risk factors for ASD. The potential association identified between the exposure to pesticides and ASD needs to be implemented and confirmed by further epidemiological studies based on individual assessment both in outdoor and indoor conditions, including multiple confounding factors, and using statistical models that take into account single and multiple pesticide residues.
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Transtorno do Espectro Autista , Hidrocarbonetos Clorados , Praguicidas , Efeitos Tardios da Exposição Pré-Natal , Transtorno do Espectro Autista/induzido quimicamente , Transtorno do Espectro Autista/epidemiologia , Criança , Feminino , Humanos , Hidrocarbonetos Clorados/toxicidade , Exposição Materna/estatística & dados numéricos , Praguicidas/toxicidade , Gravidez , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Efeitos Tardios da Exposição Pré-Natal/epidemiologiaRESUMO
BACKGROUND: Heat waves can be considered as an emerging challenge among the potential health risks generated by urbanization and climate changes. Heat waves are becoming more frequent, long and intense, and can be defined as meteorological extreme events consisting in prolonged time of extremely high temperatures in a particular region. The following paper addresses health threats due to heat waves presenting the case study of Lecce, a city located in Southern Italy; the Mediterranean area is already recognized in international literature as a hot-spot for climate changes. This work assesses the potential impact of two different adaptation strategies. METHODS: We have tested the effectiveness of cool surfaces and urban forestry as adaptation approaches to cope with heat waves. The microclimate computer-based model "ENVI-met" was adopted to predict thermal scenarios arising from the two proposed interventions. The parameters analysed consisted in temperature and relative humidity. RESULTS: Urban forestry approach seem to lower temperature (that represents the major cause of urban overheating) better than cool surfaces strategy, but relative humidity produced by the evapotranspiration processes of urban forestry has also negative influences on temperature perceived by pedestrians (thermal discomfort). CONCLUSION: Vegetation represents both an adaptation and a mitigation strategy to climate changes that guarantees an improvement of air quality, with consequent psychological and physical benefits. Wide campaigns aimed at planting trees and increasing the urban green coverage should be systematically planned and fostered by national, regional and local institutions preferably with the involvement of research departments, schools and citizens' associations.
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Temperatura Alta , Microclima , Cidades , Itália , TemperaturaRESUMO
Background: Phosphorylation of the intracellular domain of the EPHA2 receptor tyrosine kinase (RTK) on serine 897 (S897) has been demonstrated to mediate EPHA2 oncogenic activity. Here, we show that in thyroid cancer cells harboring driver oncogenes that signal through the extracellular regulated kinase (ERK1/2) signaling pathway [rearranged RET RTK (RET/PTC), KRAS(G12R), or BRAFV600E oncogenes], EPHA2 is robustly phosphorylated on S897. EPHA2 S897 is embedded in a consensus sequence for phosphorylation by the AGC family kinases, including p90RSK (ribosomal protein S6 kinase), a direct ERK1/2 target. Methods: We show that recombinant p90RSK phosphorylates in vitro EPHA2 S897 and that treatment with chemical inhibitors targeting p90RSK or other components of the ERK1/2 pathway blunts S897 phosphorylation. Results: RNA interference-mediated knockdown combined with rescue experiments demonstrated that EPHA2 S897 phosphorylation mediates thyroid cancer cell proliferation and motility. Conclusions: These findings point to EPHA2 S897 as a crucial mediator of the oncogenic activity of the ERK1/2 signaling cascade in thyroid cancer.
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Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Receptor EphA2/metabolismo , Neoplasias da Glândula Tireoide/enzimologia , Animais , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Rearranjo Gênico , Humanos , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Invasividade Neoplásica , Fosforilação , Mutação Puntual , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas c-ret/genética , Receptor EphA2/genética , Proteínas Quinases S6 Ribossômicas 90-kDa/metabolismo , Serina , Transdução de Sinais , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/patologiaRESUMO
BACKGROUND: The lysosomal enzyme α-L-Fucosidase-1 (FUCA-1) catalyzes the hydrolytic cleavage of terminal fucose residues. FUCA-1 gene is down-regulated in highly aggressive and metastatic human tumors as its inactivation perturbs the fucosylation of proteins involved in cell adhesion, migration and metastases. RESULTS: Negativity to FUCA-1 was significantly related to the development of later recurrences in breast cancer patients with lymph node involvement at diagnosis. Cancer specific survival of luminal B LN+ patients was influenced by FUCA-1 expression as luminal B LN+ patients with positive expression had a longer cancer specific survival. FUCA-1 mRNA expression was inversely related to cancer stage and lymph node involvement. WB and qPCR analysis of FUCA-1 expression in breast cancer-derived cell lines confirmed an inverse relationship with tumor aggressiveness. CONCLUSIONS: This study shows that, within LN+ breast cancer patients, FUCA-1 is able to identify a sub-set of non recurrent patients characterized by the positive expression of FUCA-1 and that, within luminal B LN+ patients, the expression of FUCA-1 predicts longer cancer specific survival. METHODS: We have analyzed FUCA-1 in 305 breast cancer patients by Immunohistochemistry (IHC), and by qPCR in breast cancer patients and in breast cancer cell lines.
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INTRODUCTION: Osimertinib showed great clinical efficacy for activated-EGFR NCLC patient treatment. The aim of this work was to test the efficacy of a complete EGFR-inhibition by osimertinib plus the monoclonal antibody cetuximab or the MEK1/2-inhibitor selumetinib in EGFR-mutated NCLC in vivo models. METHODS: We evaluated combinations of osimertinib plus selumetinib/cetuximab in HCC827 (E746-A759del/T790M-), H1975 (L858R/T790M+), and PC9-T790M (E746-A759del /T790M+) xenografts in second-line therapy after the development of resistance to osimertinib, and in first-line therapy, and we explored mechanisms of resistance to these treatments. RESULTS: The addition of selumetinib or cetuximab to osimertinib in second-line therapy reverted the sensibility to osimertinib in the majority of mice, with a response rate (RR) of 50% to 80%, and a median progression-free survival (mPFS) of first- plus second-line of therapy of 28 weeks. The early use of combinations in first-line therapy increased the RR to 90%, with an mPFS not reached in all combination arms in the three xenografts models, with a statistically significant superiority (p < 0.005) as compared to osimertinib, achieving in first-line therapy an mPFS time of 17 to 18 weeks. Moreover, in ex vivo primary cell cultures obtained from osimertinib plus selumetinib-resistant tumors, we found Hedgehog pathway activation and we showed that therapy with an SMO inhibitor plus osimertinib and selumetinib inhibited proliferation and migratory and invasive properties of resistant cells. CONCLUSIONS: We showed that a dual vertical EGFR blockade with osimertinib plus selumetinib/cetuximab is a novel effective therapeutic option in EGFR-mutated NCLC and that hedgehog pathway activation and its interplay with MAPK is involved in resistance to these combination treatments.
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Acrilamidas/uso terapêutico , Compostos de Anilina/uso terapêutico , Benzimidazóis/uso terapêutico , Cetuximab/uso terapêutico , Receptores ErbB/uso terapêutico , Inibidores de Proteínas Quinases/uso terapêutico , Acrilamidas/farmacologia , Compostos de Anilina/farmacologia , Animais , Benzimidazóis/farmacologia , Cetuximab/farmacologia , Receptores ErbB/farmacologia , Feminino , Humanos , Camundongos , Inibidores de Proteínas Quinases/farmacologia , Transdução de SinaisRESUMO
Sonic Hedgehog (Shh) pathway regulates embryonic development of different organs including the thyroid gland. The aberrant activation of Shh signaling has been found in several types of cancer and according to recent evidences it represents an important regulator of tumor-stroma interaction. In this study, we have analyzed expression, activation and molecular mechanisms regulating the Shh pathway and its involvement in the modulation of tumor stroma interaction in anaplastic thyroid cancer (ATC) cells. Our results suggest that Shh signaling undergoes a dual mechanism of induction in ATC cells: 1) a basal non-canonical Smo-dependent activation of Gli transcription factor that is partly caused by interaction with the RAS/BRAF/MEK oncogenic pathway and is characterized by the absence of Shh ligand expression in thyroid cancer cells and 2) a paracrine response of cancer cells to Shh ligand secreted by tumor stroma (fibroblasts and mesenchymal stromal cells, MSCs) inducing cancer cell migration and in vitro tumorigenesis. Our data therefore suggest Shh as a potential novel therapeutic target in aggressive thyroid cancers.
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Medullary thyroid carcinomas (MTC) arise from thyroid parafollicular, calcitonin-producing C-cells and can occur either as sporadic or as hereditary diseases in the context of familial syndromes, including multiple endocrine neoplasia 2A (MEN2A), multiple endocrine neoplasia 2B (MEN2B) and familial MTC (FMTC). In a large fraction of sporadic cases, and virtually in all inherited cases of MTC, activating point mutations of the RET proto-oncogene are found. RET encodes for a receptor tyrosine kinase protein endowed with transforming potential on thyroid parafollicular cells. As in other cancer types, microenvironmental factors play a critical role in MTC. Tumor-associated extracellular matrix, stromal cells and immune cells interact and influence the behavior of cancer cells both in a tumor-promoting and in a tumor-suppressing manner. Several studies have shown that, besides the neoplastic transformation of thyroid C-cells, a profound modification of tumor microenvironment has been associated to the RET FMTC/MEN2-associated oncoproteins. They influence the surrounding stroma, activating cancer-associated fibroblasts (CAFs), promoting cancer-associated inflammation and suppressing anti-cancer immune response. These mechanisms might be exploited to develop innovative anti-cancer therapies and novel prognostic tools in the context of familial, RET-associated MTC.
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Carcinoma Neuroendócrino , Neoplasia Endócrina Múltipla Tipo 2a , Proteínas Proto-Oncogênicas c-ret , Neoplasias da Glândula Tireoide , Microambiente Tumoral/imunologia , Animais , Carcinoma Neuroendócrino/imunologia , Carcinoma Neuroendócrino/metabolismo , Carcinoma Neuroendócrino/terapia , Humanos , Imunoterapia , Neoplasia Endócrina Múltipla Tipo 2a/imunologia , Neoplasia Endócrina Múltipla Tipo 2a/metabolismo , Neoplasia Endócrina Múltipla Tipo 2a/terapia , Proto-Oncogene Mas , Proteínas Proto-Oncogênicas c-ret/imunologia , Proteínas Proto-Oncogênicas c-ret/metabolismo , Neoplasias da Glândula Tireoide/imunologia , Neoplasias da Glândula Tireoide/metabolismo , Neoplasias da Glândula Tireoide/terapiaRESUMO
Glycans containing α-L-fucose participate in diverse interactions between cells and extracellular matrix. High glycan expression on cell surface is often associated with neoplastic progression. The lysosomal exoenzyme, α-L-fucosidase-1 (FUCA-1) removes fucose residues from glycans. The FUCA-1 gene is down-regulated in highly aggressive and metastatic human tumors. However, the role of FUCA-1 in tumor progression remains unclear. It is speculated that its inactivation perturbs glycosylation of proteins involved in cell adhesion and promotes cancer. FUCA-1 expression of various thyroid normal and cancer tissues assayed by immunohistochemical (IHC) staining was high in normal thyroids and papillary thyroid carcinomas (PTC), whereas it progressively decreased in poorly differentiated, metastatic and anaplastic thyroid carcinomas (ATC). FUCA-1 mRNA expression from tissue samples and cell lines and protein expression levels and enzyme activity in thyroid cancer cell lines paralleled those of IHC staining. Furthermore, ATC-derived 8505C cells adhesion to human E-selectin and HUVEC cells was inhibited by bovine α-L-fucosidase or Lewis antigens, thus pointing to an essential role of fucose residues in the adhesive phenotype of this cancer cell line. Finally, 8505C cells transfected with a FUCA-1 containing plasmid displayed a less invasive phenotype versus the parental 8505C. These results demonstrate that FUCA-1 is down-regulated in ATC compared to PTC and normal thyroid tissues and cell lines. As shown for other human cancers, the down-regulation of FUCA-1 correlates with increased aggressiveness of the cancer type. This is the first report indicating that the down-regulation of FUCA-1 is related to the increased aggressiveness of thyroid cancer.
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Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/patologia , alfa-L-Fucosidase/genética , Anaplasia , Animais , Bovinos , Adesão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular , Selectina E/metabolismo , Ativação Enzimática , Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Inativação Gênica , Humanos , Imuno-Histoquímica , Invasividade Neoplásica , Metástase Neoplásica , Ligação Proteica , alfa-L-Fucosidase/metabolismo , alfa-L-Fucosidase/farmacologiaRESUMO
Tumor stroma-secreted growth factors, cytokines, and reactive oxygen species (ROS) influence tumor development from early stages to the metastasis phase. Previous studies have demonstrated downregulation of ROS-producing extracellular superoxide dismutase (SOD3) in thyroid cancer cell lines although according to recent data, the expression of SOD3 at physiological levels stimulates normal and cancer cell proliferation. Therefore, to analyze the expression of SOD3 in tumor stroma, we characterized stromal cells from the thyroid. We report mutually exclusive desmoplasia and inflammation in papillary and follicular thyroid cancers and the presence of multipotent mesenchymal stem/stromal cells (MSCs) in non-carcinogenic thyroids and papillary thyroid cancer (PTC). The phenotypic and differentiation characteristics of Thyroid MSCs and PTC MSCs were comparable with bone marrow MSCs. A molecular level analysis showed increased FIBROBLAST ACTIVATING PROTEIN, COLLAGEN 1 TYPE A1, TENASCIN, and SOD3 expression in PTC MSCs compared to Thyroid MSCs, suggesting the presence of MSCs with a fibrotic fingerprint in papillary thyroid cancer tumors and the autocrine-paracrine conversion of SOD3 expression, which was enhanced by cancer cells. Stromal SOD3 had a stimulatory effect on cancer cell growth and an inhibitory effect on cancer cell migration, thus indicating that SOD3 might be a novel player in thyroid tumor stroma.
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Carcinoma Papilar/enzimologia , Carcinoma Papilar/patologia , Movimento Celular , Espaço Extracelular/enzimologia , Células-Tronco Mesenquimais/patologia , Superóxido Dismutase/metabolismo , Neoplasias da Glândula Tireoide/enzimologia , Neoplasias da Glândula Tireoide/patologia , Adenocarcinoma Folicular/enzimologia , Adenocarcinoma Folicular/patologia , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Carcinoma Papilar/genética , Proliferação de Células , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Fibrose , Regulação Neoplásica da Expressão Gênica , Humanos , Comunicação Parácrina , Fenótipo , Câncer Papilífero da Tireoide , Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/genéticaRESUMO
RET, BRAF and other protein kinases have been identified as major molecular players in thyroid cancer. To identify novel kinases required for the viability of thyroid carcinoma cells, we performed a RNA interference screening in the RET/PTC1(CCDC6-RET)-positive papillary thyroid cancer cell line TPC1 using a library of synthetic small interfering RNAs (siRNAs) targeting the human kinome and related proteins. We identified 14 hits whose silencing was able to significantly reduce the viability and the proliferation of TPC1 cells; most of them were active also in BRAF-mutant BCPAP (papillary thyroid cancer) and 8505C (anaplastic thyroid cancer) and in RAS-mutant CAL62 (anaplastic thyroid cancer) cells. These included members of EPH receptor tyrosine kinase family as well as SRC and MAPK (mitogen activated protein kinases) families. Importantly, silencing of the identified hits did not affect significantly the viability of Nthy-ori 3-1 (hereafter referred to as NTHY) cells derived from normal thyroid tissue, suggesting cancer cell specificity. The identified proteins are worth exploring as potential novel druggable thyroid cancer targets.
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Proliferação de Células/genética , Proteínas Quinases/genética , Interferência de RNA , RNA Interferente Pequeno/genética , Carcinoma Papilar/genética , Carcinoma Papilar/metabolismo , Carcinoma Papilar/patologia , Linhagem Celular Tumoral , Sobrevivência Celular/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Proteínas Quinases/metabolismo , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas B-raf/metabolismo , Proteínas Proto-Oncogênicas c-ret/genética , Proteínas Proto-Oncogênicas c-ret/metabolismo , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/metabolismo , Neoplasias da Glândula Tireoide/patologiaRESUMO
PURPOSE: Metformin, widely used as antidiabetic drug, showed antitumoral effects expecially in combination with chemotherapy. Our group recently has demonstrated that metformin and gefitinib are synergistic in LKB1-wild-type NSCLC cells. In these models, metformin as single agent induced an activation and phosphorylation of mitogen-activated-protein-kinase (MAPK) through an increased C-RAF/B-RAF heterodimerization. EXPERIMENTAL DESIGN: Since single agent metformin enhances proliferating signals through the RAS/RAF/MAPK pathway, and several MEK inhibitors (MEK-I) demonstrated clinical efficacy in combination with other agents in NSCLC, we tested the effects of metformin plus MEK-I (selumetinib or pimasertib) on proliferation, invasiveness, migration abilities in vitro and in vivo in LKB1 positive NSCLC models harboring KRAS wild type and mutated gene. RESULTS: The combination of metformin with MEK-I showed a strong anti-proliferative and proapoptotic effect in Calu-3, H1299, H358 and H1975 human NSCLC cell lines, independently from the KRAS mutational status. The combination reduced the metastatic behaviour of NSCLC cells, via a downregulation of GLI1 trascritional activity, thus affecting the transition from an epithelial to a mesenchymal phenotype. Metformin and MEK-Is combinations also decreased the production and activity of MMP-2 and MMP-9 by reducing the NF-jB (p65) binding to MMP-2 and MMP-9 promoters. CONCLUSIONS: Metformin potentiates the antitumor activity of MEK-Is in human LKB1-wild-type NSCLC cell lines, independently from the KRAS mutational status, through GLI1 downregulation and by reducing the NF-jB (p65)-mediated transcription of MMP-2 and MMP-9.
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Carcinoma Pulmonar de Células não Pequenas/patologia , Sinergismo Farmacológico , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , MAP Quinase Quinase 1/antagonistas & inibidores , Metformina/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/metabolismo , Fatores de Transcrição/metabolismo , Quinases Proteína-Quinases Ativadas por AMP , Animais , Protocolos de Quimioterapia Combinada Antineoplásica , Apoptose/efeitos dos fármacos , Benzimidazóis/farmacologia , Western Blotting , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Proliferação de Células/efeitos dos fármacos , Imunoprecipitação da Cromatina , Feminino , Humanos , Hipoglicemiantes/farmacologia , Técnicas Imunoenzimáticas , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/secundário , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Niacinamida/análogos & derivados , Niacinamida/farmacologia , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto , Proteína GLI1 em Dedos de ZincoRESUMO
The hedgehog (Hh) signaling pathway, which is almost completely silenced in normal adult tissues but highly activated in cancer, offers ideal drug targets for small molecule development. During the last few years, several studies have indicated that the Hh pathway plays a role in tumor development and maintenance, and novel drugs inhibiting Hh signaling have been discovered. Although results from clinical trials in patients harboring activating mutations of Hh have been promising, there are many controversies regarding the role of the pathway in tumors that demonstrate ligand over-expression without identified mutations. In this review, we focus on the function and expression of the Hh pathway in different tumors and discuss the targeting approaches tested in preclinical and clinical studies.
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Proteínas Hedgehog/antagonistas & inibidores , Terapia de Alvo Molecular , Neoplasias/tratamento farmacológico , Proteínas Oncogênicas/antagonistas & inibidores , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Transdução de Sinais , Transativadores/antagonistas & inibidores , Ensaios Clínicos Fase I como Assunto , Ensaios Clínicos Fase II como Assunto , Ensaios Clínicos Fase III como Assunto , Proteínas Hedgehog/metabolismo , Humanos , Neoplasias/metabolismo , Proteínas Oncogênicas/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Receptor Smoothened , Transativadores/metabolismo , Proteína GLI1 em Dedos de ZincoRESUMO
Growth factors of the bombesin/gastrin releasing peptide (BN/GRP) family play a critical role in proliferation and progression of malignancies. Inhibitors targeting GRP signalling have been developed and tested as anticancer compounds showing promising preclinical and early phase clinical results. In this review, we will discuss the molecular signaling, expression and the functional role of BN/GRP-GRPR in different cancer models and will focus on the available strategies to target BN/GRP-GRPR in cancer treatment as well as in tumour diagnosis and follow up.
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Antineoplásicos/uso terapêutico , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Receptores da Bombesina/antagonistas & inibidores , Animais , Antineoplásicos/farmacologia , Bombesina/análogos & derivados , Bombesina/farmacologia , Bombesina/uso terapêutico , Ensaios Clínicos como Assunto , Feminino , Peptídeo Liberador de Gastrina/metabolismo , Humanos , Indóis/farmacologia , Indóis/uso terapêutico , Masculino , Neoplasias/diagnóstico , Fragmentos de Peptídeos/farmacologia , Fragmentos de Peptídeos/uso terapêutico , Transdução de Sinais/efeitos dos fármacosRESUMO
NCOA4 is a transcriptional coactivator of nuclear hormone receptors that undergoes gene rearrangement in human cancer. By combining studies in Xenopus laevis egg extracts and mouse embryonic fibroblasts (MEFs), we show here that NCOA4 is a minichromosome maintenance 7 (MCM7)-interacting protein that is able to control DNA replication. Depletion-reconstitution experiments in Xenopus laevis egg extracts indicate that NCOA4 acts as an inhibitor of DNA replication origin activation by regulating CMG (CDC45/MCM2-7/GINS) helicase. NCOA4(-/-) MEFs display unscheduled origin activation and reduced interorigin distance; this results in replication stress, as shown by the presence of fork stalling, reduction of fork speed, and premature senescence. Together, our findings indicate that NCOA4 acts as a regulator of DNA replication origins that helps prevent inappropriate DNA synthesis and replication stress.
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Replicação do DNA , Coativadores de Receptor Nuclear/fisiologia , Origem de Replicação , Animais , Células Cultivadas , Senescência Celular , Células HeLa , Humanos , Camundongos , Componente 7 do Complexo de Manutenção de Minicromossomo/metabolismo , Coativadores de Receptor Nuclear/metabolismo , Técnicas do Sistema de Duplo-Híbrido , Xenopus laevisRESUMO
AIMS: Rat sarcoma virus (RAS)-induced tumorigenesis has been suggested to follow a three-stage model consisting of an initial RAS activation, senescence induction, and evasion of p53-dependent senescence checkpoints. While reactive oxygen species act as second messengers in RAS-induced senescence, they are also involved in oncogenic transformation by inducing proliferation and promoting mutations. In the current work, we investigated the role of extracellular superoxide dismutase (SOD3) in RAS-induced senescence and immortalization in vitro and in vivo. We used a mouse embryonic fibroblast (MEF) primary cell model along with immortalized and transformed human cell lines derived from papillary and anaplastic thyroid cancer. RESULTS: Based on our data, sod3 RNA interference in H-RasV12-transduced cells markedly inhibited cell growth, while sod3 over-expression in MEFs initially caused a proliferative burst followed by the activation of DNA damage checkpoints, induction of p53-p21 signal transduction, and senescence. Subsequently, sod3-transduced MEF cells developed co-operative p21-p16 down-regulation and acquired transformed cell characteristics such as increased telomerase activity, loss of contact inhibition, growth in low-nutrient conditions, and in vivo tumorigenesis. Interestingly, as previously reported with RAS, we showed a dose-dependent response to SOD3 in vitro and in vivo involving transcriptional and non-transcriptional regulatory mechanisms. INNOVATION: SOD3 may mediate H-RasV12-induced initiation of primary cell immortalization. CONCLUSIONS: Our results indicate that SOD3 influences growth signaling in primary and cancer cells downstream of the ras oncogene and could serve as a therapy target at an early tumorigenesis phase.
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Transformação Celular Neoplásica , Embrião de Mamíferos/metabolismo , Superóxido Dismutase/metabolismo , Animais , Embrião de Mamíferos/citologia , Fibroblastos/citologia , CamundongosRESUMO
Anaplastic thyroid carcinoma (ATC) is a very aggressive thyroid cancer. forkhead box protein M1 (FOXM1) is a member of the forkhead box family of transcription factors involved in control of cell proliferation, chromosomal stability, angiogenesis, and invasion. Here, we show that FOXM1 is significantly increased in ATCs compared with normal thyroid, well-differentiated thyroid carcinomas (papillary and/or follicular), and poorly differentiated thyroid carcinomas (P=0.000002). Upregulation of FOXM1 levels in ATC cells was mechanistically linked to loss-of-function of p53 and to the hyperactivation of the phosphatidylinositol-3-kinase/AKT/FOXO3a pathway. Knockdown of FOXM1 by RNA interference inhibited cell proliferation by arresting cells in G2/M and reduced cell invasion and motility. This phenotype was associated with decreased expression of FOXM1 target genes, like cyclin B1 (CCNB1), polo-like kinase 1 (PLK1), Aurora B (AURKB), S-phase kinase-associated protein 2 (SKP2), and plasminogen activator, urokinase: uPA (PLAU). Pharmacological inhibition of FOXM1 in an orthotopic mouse model of ATC reduced tumor burden and metastasization. All together, these findings suggest that FOXM1 represents an important player in thyroid cancer progression to the anaplastic phenotype and a potential therapeutic target for this fatal cancer.
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Fatores de Transcrição Forkhead/biossíntese , Neoplasias da Glândula Tireoide/metabolismo , Animais , Linhagem Celular , Linhagem Celular Tumoral , Proliferação de Células , Células Cultivadas , Feminino , Proteína Forkhead Box M1 , Fatores de Transcrição Forkhead/genética , Humanos , Camundongos , Camundongos SCID , Invasividade Neoplásica , Fenótipo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Interferência de RNA , RNA Interferente Pequeno/genética , Carcinoma Anaplásico da Tireoide , Glândula Tireoide/citologia , Neoplasias da Glândula Tireoide/patologia , Proteína Supressora de Tumor p53/metabolismo , CicatrizaçãoRESUMO
CD44 is a marker of cancer stem-like cells and epithelial-mesenchymal transition that is overexpressed in many cancer types, including thyroid carcinoma. At extracellular and intramembranous domains, CD44 undergoes sequential metalloprotease- and γ-secretase-mediated proteolytic cleavage, releasing the intracellular protein fragment CD44-ICD, which translocates to the nucleus and activates gene transcription. Here, we show that CD44-ICD binds to the transcription factor CREB, increasing S133 phosphorylation and CREB-mediated gene transcription. CD44-ICD enhanced CREB recruitment to the cyclin D1 promoter, promoting cyclin D1 transcription and cell proliferation. Thyroid carcinoma cells harboring activated RET/PTC, RAS, or BRAF oncogenes exhibited CD44 cleavage and CD44-ICD accumulation. Chemical blockade of RET/PTC, BRAF, metalloprotease, or γ-secretase were each sufficient to blunt CD44 processing. Furthermore, thyroid cancer cell proliferation was obstructed by RNA interference-mediated knockdown of CD44 or inhibition of γ-secretase and adoptive CD44-ICD overexpression rescued cell proliferation. Together, these findings reveal a CD44-CREB signaling pathway that is needed to sustain cancer cell proliferation, potentially offering new molecular targets for therapeutic intervention in thyroid carcinoma.
Assuntos
Carcinoma Papilar/patologia , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Receptores de Hialuronatos/metabolismo , Proteólise , Neoplasias da Glândula Tireoide/patologia , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Secretases da Proteína Precursora do Amiloide/genética , Animais , Carcinoma Papilar/genética , Carcinoma Papilar/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Ciclina D1/genética , Ciclina D1/metabolismo , Humanos , Metaloproteases/antagonistas & inibidores , Metaloproteases/genética , Oncogenes/efeitos dos fármacos , Fosforilação , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-ret/genética , Proteínas Proto-Oncogênicas c-ret/metabolismo , Ratos , Transdução de Sinais , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/metabolismo , Transcrição GênicaRESUMO
BACKGROUND: Extracellular superoxide dismutase (SOD3), which dismutates superoxide anion to hydrogen peroxide, has been shown to reduce the free radical stress derived apoptosis in tissue injuries. Since both superoxide anion and hydrogen peroxide have a marked impact on signal transduction pathways and could potentially explain a number of apoptosis and survival -related phenomena in different pathological conditions, we clarified the impact of SOD3 on Akt and Erk1/2 cell survival pathways in rat hind limb injury model. METHODOLOGY AND PRINCIPAL FINDINGS: Based on our data, the hind limb ischemic rats treated with virally delivered sod3 have milder injury and less apoptosis than control animals that could be due to parallel activation of pro-proliferative and anti-apoptotic Erk1/2 and Akt pathways. The common downstream factor of both signaling pathways, the apoptosis related forkhead box protein O3a (FoxO3a), was phosphorylated and translocated to the cytoplasm in sod3 treated tissues and cell line. Additionally, we obtained increased mRNA production of elk-1, ets-1, and microRNA 21 (miR-21), whereas synthesis of bim mRNA was decreased in sod3 overexpressing tissues. We further showed that overexpression of sod3 modulated redox related gene expression by downregulating nox2 and inos when compared to injured control animals. CONCLUSIONS AND SIGNIFICANCE: The study shows the complexity of SOD3-derived effects on tissue injury recovery that are not limited to the reduction of superoxide anion caused cellular stress but highlights the impact of SOD3 related signal transduction on tissue functions and suggests an important role for SOD3 in attenuating cell stress effects in different pathological conditions.