Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
Kidney Blood Press Res ; 47(7): 467-474, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35318291

RESUMO

INTRODUCTION: Since the pandemic of COVID-19 started from December 2019, remarkable numbers of infections and deaths associated with COVID-19 have been recorded worldwide. End-stage kidney disease patients on dialysis are particularly at high risk of infections due to impairments in the innate and adaptive immune systems. Vaccination on dialysis patients (DP) still remains challenging because of the variable response and a low seroconversion rate compared with healthy participants (HP). Therefore, it is urgently necessary to establish a different vaccination strategy for DP, in terms of the dose and administration time. METHODS: Here, we report an observational prospective cohort study in which the immunogenic efficacies of SARS-CoV-2 vaccine BNT162b2 on DP and HP were evaluated by absolute quantification of IgG levels in the blood. RESULTS: DP showed a delayed seroconversion after two vaccine doses, with a low absolute IgG levels compared to HP. While HP reached complete seroconversion within 10 days from the administration of a second dose, only 76% of DP were seropositive. After the booster dose, DP had a strongly improved seroconversion rate as well as antibody levels, reaching 97% seropositivity and 50 times enhancement on antibody levels. DISCUSSION/CONCLUSION: These results prompt to suggest an additional vaccine dose in DP, reducing the interval of time from the second dose. Since limited data are available on immune response in DP overtime after three vaccine doses currently, our study is among the first reports demonstrating the improved seropositivity and IgG levels in DP after the booster vaccine dose.


Assuntos
COVID-19 , Vacinas Virais , Anticorpos Antivirais , Vacina BNT162 , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Estudos de Coortes , Humanos , Imunidade , Imunoglobulina G , Estudos Prospectivos , Diálise Renal , SARS-CoV-2 , Vacinação
2.
Eur J Med Chem ; 228: 113971, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34772529

RESUMO

Hybrid molecules targeting simultaneously DNA polymerase α (POLA1) and histone deacetylases (HDACs) were designed and synthesized to exploit a potential synergy of action. Among a library of screened molecules, MIR002 and GEM144 showed antiproliferative activity at nanomolar concentrations on a panel of human solid and haematological cancer cell lines. In vitro functional assays confirmed that these molecules inhibited POLA1 primer extension activity, as well as HDAC11. Molecular docking studies also supported these findings. Mechanistically, MIR002 and GEM144 induced acetylation of p53, activation of p21, G1/S cell cycle arrest, and apoptosis. Oral administration of these inhibitors confirmed their antitumor activity in in vivo models. In human non-small cancer cell (H460) xenografted in nude mice MIR002 at 50 mg/kg, Bid (qd × 5 × 3w) inhibited tumor growth (TGI = 61%). More interestingly, in POLA1 inhibitor resistant cells (H460-R9A), the in vivo combination of MIR002 with cisplatin showed an additive antitumor effect with complete disappearance of tumor masses in two animals at the end of the treatment. Moreover, in two human orthotopic malignant pleural mesothelioma xenografts (MM473 and MM487), oral treatments with MIR002 and GEM144 confirmed their significant antitumor activity (TGI = 72-77%). Consistently with recent results that have shown an inverse correlation between POLA1 expression and type I interferon levels, MIR002 significantly upregulated interferon-α in immunocompetent mice.


Assuntos
Antineoplásicos/farmacologia , DNA Polimerase I/antagonistas & inibidores , Inibidores de Histona Desacetilases/farmacologia , Histona Desacetilases/metabolismo , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , DNA Polimerase I/metabolismo , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores de Histona Desacetilases/síntese química , Inibidores de Histona Desacetilases/química , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Nus , Estrutura Molecular , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Relação Estrutura-Atividade , Células Tumorais Cultivadas
3.
Viruses ; 13(8)2021 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-34452527

RESUMO

CONTEXT: The Global Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) pandemic has resulted in explosive patterns of transmission in most countries. Nasopharyngeal swabs were the specimen's collection tools recommended for the diagnosis of SARS-CoV-2 infection, and for monitoring infection outbreaks in communities. Our objective was to report the quality and efficacy of unsupervised self-collected mid turbinate "dry FLOQSwabs" (MT FLOQSwabs) (56380CS01, Copan). There were 111 specimens collected for the study: 36 by health care personnel, from themselves, to verify the quality and efficacy of mid-turbinate swabs; 75 to compare and assess the diagnostic performance, among health care personnel, of nasopharyngeal swabs and self-collected mid-turbinate FLOQSwabs. A collection of 51 specimens was enrolled to define the efficacy of the Testami program (validation). Our analyses demonstrate that self-collected mid-turbinate dry swabs ensure an accuracy of 97.3%, as compared to the standard nasopharyngeal swabs collected by health care workers. Furthermore, the mid-turbinate FLOQSwabs can be stored without medium for six days at room temperature without affecting the molecular diagnosis of the SARS-CoV-2 virus infection. Self-collection of diagnostic specimens at home could offer an avenue to increase testing availability for SARS-CoV-2 infection without asking people to travel to a clinic or a laboratory, thus reducing people's exposure to infection. Our findings demonstrate that unsupervised self-collection swabs, transported dry, are sensitive, practical and easy-to-use tools and should be considered for diagnosis of SARS-COV-2 and coronavirus disease 2019 (COVID-19) surveillance.


Assuntos
Teste de Ácido Nucleico para COVID-19 , COVID-19/diagnóstico , Manejo de Espécimes , Conchas Nasais/virologia , Humanos , Nasofaringe/virologia , Valor Preditivo dos Testes , Sensibilidade e Especificidade , Manejo de Espécimes/instrumentação , Manejo de Espécimes/métodos
4.
Bioorg Chem ; 104: 104253, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32920362

RESUMO

Atypical retinoids (AR) or retinoid-related molecules (RRMs) represent a promising class of antitumor compounds. Among AR, E-3-(3'-adamantan-1-yl-4'-hydroxybiphenyl-4-yl)acrylic acid (adarotene), has been extensively investigated. In the present work we report the results of our efforts to develop new adarotene-related atypical retinoids endowed also with POLA1 inhibitory activity. The effects of the synthesized compounds on cell growth were determined on a panel of human and hematological cancer cell lines. The most promising compounds showed antitumor activity against several tumor histotypes and increased cytotoxic activity against an adarotene-resistant cell line, compared to the parent molecule. The antitumor activity of a selected compound was evaluated on HT-29 human colon carcinoma and human mesothelioma (MM487) xenografts. Particularly significant was the in vivo activity of the compound as a single agent compared to adarotene and cisplatin, against pleural mesothelioma MM487. No reduction of mice body weight was observed, thus suggesting a higher tolerability with respect to the parent compound adarotene.


Assuntos
Antineoplásicos/farmacologia , DNA Polimerase I/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Retinoides/farmacologia , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , DNA Polimerase I/metabolismo , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Feminino , Humanos , Camundongos , Camundongos Nus , Estrutura Molecular , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Retinoides/síntese química , Retinoides/química , Relação Estrutura-Atividade , Células Tumorais Cultivadas
5.
Molecules ; 25(9)2020 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-32403241

RESUMO

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease characterized by the production of inflammatory factors. In order to overcome the side effects of currently used anti-inflammatory drugs, several attempts have been made to identify natural products capable of relieving RA symptoms. In this work, a herbal preparation consisting of propolis, pomegranate peel, and Aglianico grape pomace (PPP) extracts (4:1:1) was designed and evaluated for its effect on a murine collagen-induced arthritis (CIA) model. Firstly, the chemical contents of four different Italian propolis collected in the Campania region (Italy) were here reported for the first time. LC-MS analyses showed the presence of 38 constituents, identified in all propolis extracts, belonging to flavonoids and phenolic acids classes. The Pietradefusi extract was the richest one and thus was selected to design the PPP preparation for the in vivo assay. Our results highlight the impact of PPP on RA onset and progression. By using in vivo CIA models, the treatment with PPP resulted in a delayed onset of the disease and alleviated the severity of the clinical symptoms. Furthermore, we demonstrated that early PPP treatment was associated with a reduction in serum levels of IL-17, IL-1b, and IL-17-triggering cytokines.


Assuntos
Anti-Inflamatórios/farmacologia , Artrite Reumatoide/tratamento farmacológico , Inflamação/tratamento farmacológico , Preparações de Plantas/farmacologia , Punica granatum/química , Própole/análise , Vitis/química , Animais , Anti-Inflamatórios/química , Artrite Reumatoide/induzido quimicamente , Artrite Reumatoide/fisiopatologia , Cromatografia Líquida , Colágeno/toxicidade , Feminino , Flavonoides/análise , Hidroxibenzoatos/análise , Inflamação/metabolismo , Interleucina-17/metabolismo , Interleucina-1beta/metabolismo , Espectrometria de Massas , Camundongos , Camundongos Endogâmicos DBA , Preparações de Plantas/química , Própole/química , Própole/farmacologia
6.
PLoS One ; 13(10): e0205018, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30300374

RESUMO

Recent studies have shown that HDAC inhibitors act synergistically with camptothecin derivatives in combination therapies. To exploit this synergy, new hybrid molecules targeting simultaneously topoisomerase I and HDAC were designed. In particular, a selected multivalent agent containing a camptothecin and a SAHA-like template showed a broad spectrum of antiproliferative activity, with IC50 values in the nanomolar range. Preliminary in vivo results indicated a strong antitumor activity on human mesothelioma primary cell line MM473 orthotopically xenografted in CD-1 nude mice and very high tolerability.


Assuntos
Antineoplásicos/uso terapêutico , Inibidores de Histona Desacetilases/uso terapêutico , Neoplasias/tratamento farmacológico , Inibidores da Topoisomerase I/uso terapêutico , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Sítios de Ligação , Camptotecina/química , Camptotecina/farmacologia , Camptotecina/uso terapêutico , Domínio Catalítico , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , DNA Topoisomerases Tipo I/química , DNA Topoisomerases Tipo I/metabolismo , Feminino , Inibidores de Histona Desacetilases/química , Inibidores de Histona Desacetilases/farmacologia , Humanos , Camundongos , Camundongos Nus , Simulação de Dinâmica Molecular , Neoplasias/patologia , Inibidores da Topoisomerase I/química , Inibidores da Topoisomerase I/farmacologia , Transplante Heterólogo
7.
Am J Cancer Res ; 8(1): 39-55, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29416919

RESUMO

Despite advances in therapeutic strategies, colorectal cancer (CRC) remains the third cause of cancer-related deaths with a relatively low survival rate. Resistance to standard chemotherapy represents a major hurdle in disease management; therefore, developing new therapeutic agents demands a thorough understanding of their mechanisms of action. One of these compounds is ST1926, an adamantyl retinoid that has shown potent antitumor activities in several human cancer models. Here, we show that ST1926 selectively suppressed the proliferation of CRC cells while sparing normal counterparts, and significantly reduced tumor volume in a xenograft cancer mouse model. Next, we investigated the effects of ST1926 in CRC cells and observed early DNA damage, S-phase arrest, dissipation of mitochondrial membrane potential, and apoptosis induction, in a p53 and p21-independent manner. To address the underlying mechanism of resistance to ST1926, we generated ST1926-resistant HCT116 cells and sequenced DNA polymerase α (POLA1), which was reported to be a direct target to the drug's parent molecule, CD437. We identified similar mutations in POLA1 that conferred resistance to ST1926 and CD437. These mutations were absent in 5-fluorouracil-resistant HCT116 cells, clearly validating the specificity of these mutations to the lack of DNA damage and acquired resistance to ST1926. ST1926 also inhibited POLA1 activity and reduced its protein expression levels. Further, in silico analysis of normal and malignant tissue expression data demonstrated that POLA1 levels are elevated in CRC cells and tissues compared to normal counterparts as well as to other cancer types. Our findings highlight previously uncharacterized mechanisms of action of ST1926 in CRC and suggest that elevated POLA1 expression is a pertinent molecular feature and an attractive target in CRC.

8.
Clin Cancer Res ; 21(14): 3307-17, 2015 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-25609060

RESUMO

PURPOSE: Oncogenic fusions consisting of fibroblast growth factor receptor (FGFR) and TACC are present in a subgroup of glioblastoma (GBM) and other human cancers and have been proposed as new therapeutic targets. We analyzed frequency and molecular features of FGFR-TACC fusions and explored the therapeutic efficacy of inhibiting FGFR kinase in GBM and grade II and III glioma. EXPERIMENTAL DESIGN: Overall, 795 gliomas (584 GBM, 85 grades II and III with wild-type and 126 with IDH1/2 mutation) were screened for FGFR-TACC breakpoints and associated molecular profile. We also analyzed expression of the FGFR3 and TACC3 components of the fusions. The effects of the specific FGFR inhibitor JNJ-42756493 for FGFR3-TACC3-positive glioma were determined in preclinical experiments. Two patients with advanced FGFR3-TACC3-positive GBM received JNJ-42756493 and were assessed for therapeutic response. RESULTS: Three of 85 IDH1/2 wild-type (3.5%) but none of 126 IDH1/2-mutant grade II and III gliomas harbored FGFR3-TACC3 fusions. FGFR-TACC rearrangements were present in 17 of 584 GBM (2.9%). FGFR3-TACC3 fusions were associated with strong and homogeneous FGFR3 immunostaining. They are mutually exclusive with IDH1/2 mutations and EGFR amplification, whereas they co-occur with CDK4 amplification. JNJ-42756493 inhibited growth of glioma cells harboring FGFR3-TACC3 in vitro and in vivo. The two patients with FGFR3-TACC3 rearrangements who received JNJ-42756493 manifested clinical improvement with stable disease and minor response, respectively. CONCLUSIONS: RT-PCR sequencing is a sensitive and specific method to identify FGFR-TACC-positive patients. FGFR3-TACC3 fusions are associated with uniform intratumor expression of the fusion protein. The clinical response observed in the FGFR3-TACC3-positive patients treated with an FGFR inhibitor supports clinical studies of FGFR inhibition in FGFR-TACC-positive patients.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias Encefálicas/genética , Glioma/genética , Proteínas de Fusão Oncogênica/genética , Pirazóis/uso terapêutico , Quinoxalinas/uso terapêutico , Animais , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/mortalidade , Análise Mutacional de DNA/métodos , Feminino , Imunofluorescência , Glioma/tratamento farmacológico , Glioma/mortalidade , Humanos , Imuno-Histoquímica , Isocitrato Desidrogenase/genética , Estimativa de Kaplan-Meier , Masculino , Camundongos , Camundongos Nus , Proteínas Associadas aos Microtúbulos/genética , Terapia de Alvo Molecular , Receptor Tipo 3 de Fator de Crescimento de Fibroblastos/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Ensaios Antitumorais Modelo de Xenoenxerto
9.
Neoplasia ; 15(9): 1086-99, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24027433

RESUMO

MicroRNA-130b (miR-130b) is involved in several biologic processes; its role in colorectal tumorigenesis has not been addressed so far. Herein, we demonstrate that miR-130b up-regulation exhibits clinical relevance as it is linked to advanced colorectal cancers (CRCs), poor patients' prognosis, and molecular features of enhanced epithelial-mesenchymal transition (EMT) and angiogenesis. miR-130b high-expressing cells develop large, dedifferentiated, and vascularized tumors in mouse xenografts, features that are reverted by intratumor injection of a specific antisense RNA. In contrast, injection of the corresponding mimic in mouse xenografts from miR-130b low-expressing cells increases tumor growth and angiogenic potential while reduces the epithelial hallmarks. These biologic effects are reproduced in human CRC cell lines. We identify peroxisome proliferator-activated receptor γ (PPARγ) as an miR-130b direct target in CRC in vitro and in vivo. Notably, the effects of PPARγ gain- and loss-of-function phenocopy those due to miR-130b down-regulation or up-regulation, respectively, underscoring their biologic relevance. Furthermore, we provide mechanistic evidences that most of the miR-130b-dependent effects are due to PPARγ suppression that in turn deregulates PTEN, E-cadherin, Snail, and vascular endothelial growth factor, key mediators of cell proliferation, EMT, and angiogenesis. Since higher levels of miR-130b are found in advanced tumor stages (III-IV), we propose a novel role of the miR-130b-PPARγ axis in fostering the progression toward more invasive CRCs. Detection of onco-miR-130b and its association with PPARγ may be useful as a prognostic biomarker. Its targeting in vivo should be evaluated as a novel effective therapeutic tool against CRC.


Assuntos
Transformação Celular Neoplásica/genética , Neoplasias Colorretais/genética , MicroRNAs/genética , MicroRNAs/metabolismo , PPAR gama/metabolismo , Animais , Biomarcadores Tumorais/genética , Caderinas/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Neoplasias Colorretais/patologia , Regulação para Baixo , Transição Epitelial-Mesenquimal/genética , Feminino , Células HCT116 , Humanos , Camundongos , Camundongos Nus , Invasividade Neoplásica/genética , Transplante de Neoplasias , Neovascularização Patológica/genética , PTEN Fosfo-Hidrolase/metabolismo , Prognóstico , Fatores de Transcrição da Família Snail , Fatores de Transcrição/metabolismo , Regulação para Cima , Fator A de Crescimento do Endotélio Vascular/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
10.
Diagn Pathol ; 8: 31, 2013 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-23425390

RESUMO

BACKGROUND: Rhabdoid colorectal tumor (RCT) is a rare, highly aggressive neoplasm recurrent in elderly patients, commonly at the caecum. The molecular mechanisms underlying RCT pathogenesis remain poorly elucidated. The differential diagnosis is with the malignant rhabdoid tumors of infancy characterized by genetic inactivation of SMARCB1 (INI1) or deletions of chromosome 22q12 locus. MATERIALS AND METHODS: To shed light on RCT pathogenesis, we investigated genetic and epigenetic alterations in two cases of pure and composite RCT and compared them with the profiles of matched adenomas and normal mucosa. Immunohistochemical analysis, FISH, methylation specific PCR and DNA sequencing analysis were performed on paraffin-embedded tissues. RESULTS: Loss of epithelial markers, (CK20, CDX2 and E-cadherin) and intense vimentin expression was observed in RCTs but neither in the normal mucosa or adenomas. INI1 expression was detected in normal mucosa, adenomas and retained in pure RCT, while it was undetected in composite RCT. Rearrangement of the 22q12 locus was found only in pure RCT. The APC/ß-catenin pathway was not altered, while MLH1 immunostaining was negative in RCTs and positive in adenomas and normal mucosa. These expression profiles were associated with V600E BRAF mutation, a progressive accumulation of promoter methylation at specific CIMP loci and additional genes from the normal mucosa to tubular adenoma and RCT. CONCLUSIONS: Right-sided RCT could be characterized by epigenetic events and molecular features likely similar to those occurring in the serrated pathway and associated with epithelial-mesenchymal transition. These extremely rare tumors may benefit from the use of new biological molecules specific for colorectal carcinoma. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1641385210804556.


Assuntos
Biomarcadores Tumorais/genética , Neoplasias Colorretais/genética , Epigênese Genética , Tumor Rabdoide/genética , Transdução de Sinais/genética , Adenoma/química , Adenoma/genética , Adenoma/patologia , Idoso , Biomarcadores Tumorais/análise , Cromossomos Humanos Par 22 , Neoplasias Colorretais/química , Neoplasias Colorretais/patologia , Neoplasias Colorretais/terapia , Ilhas de CpG , Metilação de DNA , Análise Mutacional de DNA , Progressão da Doença , Evolução Fatal , Feminino , Rearranjo Gênico , Predisposição Genética para Doença , Humanos , Imuno-Histoquímica , Hibridização in Situ Fluorescente , Mucosa Intestinal/química , Mucosa Intestinal/patologia , Instabilidade de Microssatélites , Mutação , Inclusão em Parafina , Fenótipo , Reação em Cadeia da Polimerase , Proteínas Proto-Oncogênicas B-raf/genética , Tumor Rabdoide/química , Tumor Rabdoide/patologia , Tumor Rabdoide/terapia , Fatores de Tempo , Resultado do Tratamento
11.
PPAR Res ; 2012: 242498, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22991505

RESUMO

Tumors of the gastrointestinal tract are among the most frequent human malignancies and account for approximately 30% of cancer-related deaths worldwide. Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors that control diverse cellular functions such as proliferation, differentiation, and cell death. Owing to their involvement in so many processes, they play crucial roles also in the development and physiology of the gastrointestinal tract. Consistently, PPARs deregulation has been implicated in several pathophysiological conditions, including chronic inflammation and cancer development. This paper summarizes the current knowledge on the role that the various PPAR isoforms play in the pathogenesis of the esophageal, gastric, and intestinal cancer. Elucidation of the molecular mechanisms underlying PPARs' signaling pathways will provide insights into their possible use as predictive biomarkers in the initial stages of the process. In addition, this understanding will provide the basis for new molecular targets in cancer therapy and chemoprevention.

12.
PPAR Res ; 2012: 687492, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22848209

RESUMO

Peroxisome proliferator-activated receptor gamma (PPARγ) plays critical roles in lipid storage, glucose metabolism, energy homeostasis, adipocyte differentiation, inflammation, and cancer. Its function in colon carcinogenesis has largely been debated; accumulating evidence, however, supports a role as tumor suppressor through modulation of crucial pathways in cell differentiation, apoptosis, and metastatic dissemination. Epigenetics adds a further layer of complexity to gene regulation in several biological processes. In cancer, the relationship with epigenetic modifications has provided important insights into the underlying molecular mechanisms. These studies have highlighted how epigenetic modifications influence PPARG gene expression in colorectal tumorigenesis. In this paper, we take a comprehensive look at the current understanding of the relationship between PPARγ and cancer development. The role that epigenetic mechanisms play is also addressed disclosing novel crosstalks between PPARG signaling and the epigenetic machinery and suggesting how this dysregulation may contribute to colon cancer development.

13.
Hum Pathol ; 42(7): 1047-52, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21315413

RESUMO

Colon carcinoma with rhabdoid characteristics is a rare, malignant tumor whose molecular alterations have not been clarified yet. We report a novel case of a colon adenocarcinoma with rhabdoid features in a 71-year-old woman, localized to the right colon and associated with local lymph node and liver metastasis. The patient died within 8 months from surgery despite target chemotherapy. The tumor was enriched in cells with a typical rhabdoid-type morphology displaying a marked and diffuse vimentin staining. Cells were also positive for epidermal growth factor receptor (EGFR), p53, Ki67, and ß-catenin and negative for cytokeratin 20/cytokeratin 7, E-cadherin, and CDX2. Remarkably, the promoter regions of 4 of 5 specific genes that define the so-called "CpG island methylator phenotype," including mutL homolog 1 (MLH1), were methylated. Consistently, microsatellite instability was detected. A BRAF V600E mutation and no KRAS mutations were identified. Finally, 4 tumor suppressor gene promoters CDH1, CDKN1B, CDKN1C, and MGMT were not methylated. This is the first case of a colorectal carcinoma with rhabdoid features, "CpG island methylator phenotype," high microsatellite instability associated with a BRAF mutation, and patient poorer outcome.


Assuntos
Neoplasias do Colo/genética , Ilhas de CpG , Metilação de DNA , Proteínas Proto-Oncogênicas B-raf/genética , Tumor Rabdoide/genética , Idoso , Neoplasias do Colo/patologia , Feminino , Humanos , Instabilidade de Microssatélites , Fenótipo , Tumor Rabdoide/patologia
14.
PLoS One ; 5(12): e14229, 2010 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-21151932

RESUMO

The relationship between peroxisome proliferator-activated receptor γ (PPARG) expression and epigenetic changes occurring in colorectal-cancer pathogenesis is largely unknown. We investigated whether PPARG is epigenetically regulated in colorectal cancer (CRC) progression. PPARG expression was assessed in CRC tissues and paired normal mucosa by western blot and immunohistochemistry and related to patients' clinicopathological parameters and survival. PPARG promoter methylation was analyzed by methylation-specific-PCR and bisulphite sequencing. PPARG expression and promoter methylation were similarly examined also in CRC derived cell lines. Chromatin immunoprecipitation in basal conditions and after epigenetic treatment was performed along with knocking-down experiments of putative regulatory factors. Gene expression was monitored by immunoblotting and functional assays of cell proliferation and invasiveness. Methylation on a specific region of the promoter is strongly correlated with PPARG lack of expression in 30% of primary CRCs and with patients' poor prognosis. Remarkably, the same methylation pattern is found in PPARG-negative CRC cell lines. Epigenetic treatment with 5'-aza-2'-deoxycytidine can revert this condition and, in combination with trichostatin A, dramatically re-activates gene transcription and receptor activity. Transcriptional silencing is due to the recruitment of MeCP2, HDAC1 and EZH2 that impart repressive chromatin signatures determining an increased cell proliferative and invasive potential, features that can experimentally be reverted. Our findings provide a novel mechanistic insight into epigenetic silencing of PPARG in CRC that may be relevant as a prognostic marker of tumor progression.


Assuntos
Biomarcadores Tumorais/genética , Neoplasias Colorretais/metabolismo , Epigênese Genética , PPAR gama/metabolismo , Idoso , Linhagem Celular Tumoral , Neoplasias Colorretais/genética , Metilação de DNA , Progressão da Doença , Feminino , Inativação Gênica , Inibidores de Histona Desacetilases/farmacologia , Humanos , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Prognóstico , Regiões Promotoras Genéticas
15.
Hum Pathol ; 41(6): 867-76, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20129645

RESUMO

Beta-catenin and p53 play key roles in tumorigenesis. The relationships between these 2 signaling pathways and their contribution to colorectal cancer metastatic progression have not been completely elucidated. We analyzed 141 cases of primary sporadic colorectal cancer, 45 matched metastases, and 80 samples of normal mucosa by immunohistochemistry on paraffin-embedded specimens. The expression profiles were also related to patients' clinicopathologic features and 5-year survival. In primary tumors, beta-catenin immunoreactivity was nuclear (27%), predominantly membrane/cytosolic (46.0%) or negative (27%). This latter subgroup was strongly related to microsatellite instability, in particular to MLH-1 deficiency. Remarkably, beta-catenin membrane/cytosolic expression in primary tumors was reduced in the corresponding matched metastases. p53 showed a significant increase in immunoreactivity in (66.7%), whereas it was negative in (33.3%) of tumors. When we considered the expression of both genes, the combination of negative beta-catenin and positive p53 nuclear staining (21%) was strongly related to a higher frequency of liver metastases. Such an association was significantly related to a worse prognosis than any other combination. In a multivariate analysis, beta-catenin and distant metastases were independent prognostic markers. We suggest that a combination of low beta-catenin and high p53 expression in primary colorectal cancers may be a prognostic factor in predicting the progression of the disease, the occurrence of metastasis, and a more severe outcome.


Assuntos
Biomarcadores Tumorais/biossíntese , Neoplasias Colorretais/diagnóstico , Proteína Supressora de Tumor p53/biossíntese , beta Catenina/biossíntese , Proteínas Adaptadoras de Transdução de Sinal/deficiência , Proteínas Adaptadoras de Transdução de Sinal/genética , Análise de Variância , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Feminino , Humanos , Imuno-Histoquímica , Neoplasias Hepáticas/secundário , Masculino , Instabilidade de Microssatélites , Pessoa de Meia-Idade , Proteína 1 Homóloga a MutL , Metástase Neoplásica , Proteínas Nucleares/deficiência , Proteínas Nucleares/genética , Prognóstico , Estudos Prospectivos , Análise de Sobrevida
16.
Int J Biochem Cell Biol ; 41(11): 2189-203, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19389484

RESUMO

Retinol-binding protein (RBP4) transports retinol in the circulation from hepatic stores to peripheral tissues. Since little is known regarding the regulation of this gene, we analysed the cis-regulatory sequences of the mouse RBP4 gene. Our data show that transcription of the gene is regulated through a bipartite promoter: a proximal region necessary for basal expression and a distal segment responsible for cAMP-induction. This latter region contains several binding sites for the structural HMGA1 proteins, which are important to promoter regulation. We further demonstrate that HMGA1s play a key role in basal and cAMP-induction of Rbp4 transcription and the RBP4 and HMGA1 genes are coordinately regulated in vitro and in vivo. HMGA1 acts to recruit transcription factors to the RBP4 promoter and we specifically identified p54(nrb)/NonO and protein-associated splicing factor (PSF) as components that interact with this complex. Steroidogenic factor 1 (SF1) or the related liver receptor homologue 1 (LRH-1) are also associated with this complex upon cAMP-induction. Depletion of SF1/LRH-1 by RNA interference resulted in a dramatic loss of cAMP-induction. Collectively, our results demonstrate that basal and cAMP-induced Rbp4 transcription is regulated by a multiprotein complex that is similar to ones that modulate expression of genes of steroid hormone biosynthesis. Since genes related to glucose metabolism are regulated in a similar fashion, this suggests that Rbp4 expression may be regulated as part of a network of pathways relevant to the onset of type 2 diabetes.


Assuntos
Proteínas HMGA/metabolismo , Proteínas Associadas à Matriz Nuclear/metabolismo , Proteínas de Ligação a RNA/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Proteínas Plasmáticas de Ligação ao Retinol/genética , Fator Esteroidogênico 1/metabolismo , Ativação Transcricional/genética , Animais , Sequência de Bases , Linhagem Celular Tumoral , AMP Cíclico/farmacologia , DNA/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Modelos Genéticos , Dados de Sequência Molecular , Complexos Multiproteicos/metabolismo , Fator de Processamento Associado a PTB , Plasmídeos/genética , Regiões Promotoras Genéticas/genética , Ligação Proteica/efeitos dos fármacos , Biossíntese de Proteínas/efeitos dos fármacos , Proteínas Plasmáticas de Ligação ao Retinol/metabolismo , Transcrição Gênica/efeitos dos fármacos , Ativação Transcricional/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA