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1.
Expert Opin Investig Drugs ; 26(3): 269-277, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28103158

RESUMO

INTRODUCTION: Research has focused on serotonin (5-HT) 5-HT1D and 5-HT1F receptors to develop drugs acting through non-vasoconstrictive mechanisms for treating acute migraine and those targeting 5-HT2B and 5-HT7 receptors for preventing migraine. Areas covered: This paper reviews antimigraine drugs targeting 5-HT receptors in one phase I trial (sumatriptan iontophoretic transdermal system, TDS) and five phase II clinical trials (PNU-142633, LY334370, lasmiditan, NOX-188). Expert opinion: Data from our overview on investigational drugs in phase I and II clinical trials using the 5-HT1B/1D receptor agonist (sumatriptan TDS), 5-HT1D receptor agonist (PNU-142633), 5-HT1F receptor agonists (LY334370, lasmiditan) and a combined 5-HT1B/1D receptor agonist with nNOS inhibition (NOX-188) provided encouraging data for sumatriptan TDS and lasmiditan, disappointing results for PNU-142633, and promising findings for NOX-188. The 5-HT1F receptor agonist lasmiditan, a drug acting through non-vasoconstrictive mechanisms, represents a promising safe, effective and tolerated acute migraine therapy also for patients at cardiovascular risk. Upcoming phase III trials should clarify the optimal lasmiditan dose and eventual clinical advantages over triptans. The negative results for the PNU-142633 trial prompt further studies using specific compounds more precisely targeting 5-HT1D receptors. Antagonism at 5-HT2B and 5-TH7 receptors, a promising strategy to prevent migraine, is still limited to experimental migraine models.


Assuntos
Drogas em Investigação/uso terapêutico , Transtornos de Enxaqueca/tratamento farmacológico , Agonistas do Receptor de Serotonina/uso terapêutico , Animais , Ensaios Clínicos Fase I como Assunto , Ensaios Clínicos Fase II como Assunto , Desenho de Fármacos , Drogas em Investigação/efeitos adversos , Drogas em Investigação/farmacologia , Humanos , Transtornos de Enxaqueca/fisiopatologia , Terapia de Alvo Molecular , Receptores de Serotonina/efeitos dos fármacos , Receptores de Serotonina/metabolismo , Agonistas do Receptor de Serotonina/administração & dosagem , Agonistas do Receptor de Serotonina/farmacologia
2.
Curr Med Chem ; 22(33): 3765-88, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26264924

RESUMO

Senescence is a phenomenon characterized by a progressive decline of body homeostasis. Premature senescence acts when the cellular system is not able to adequately respond to noxious stimuli by synthesis of stressor molecules. Among those, serum-and-glucocorticoidinducible kinase-1 (SGK-1) dramatically increases under typical physiopathological conditions, such as glucocorticoid or mineralcorticoids exposure, inflammation, hyperglycemia, and ischemia. SGK-1 has been implicated in mechanism regulating oxidative stress, apoptosis, and DNA damage, which are all leading to a state of accelerating aging. Moreover, SGK-1-sensitive ion channels participate in the regulation of renal Na(+)/K(+) regulation, blood pressure, gastric acid secretion, cardiac action potential, and neuroexcitability. Recently, we demonstrated in endothelial cells as an increase in SGK-1 activity and expression reduces oxidative stress, improves cell survival and restores insulin-mediated nitric oxide production after hyperglycemia. Moreover, we showed as SGK-1 delays the onset of senescence by increasing telomerase activity, significantly decreasing reactive oxygen species (ROS) production, and by directly interacting with hTERT. Therefore, SGK-1 may represent a specific target to further develop novel therapeutic options against chronic diseases such as diabetes typical of aging. SGK-1 has been also associated with cancer, neurodegenerative diseases, and cardiovascular disease, among other age-related diseases. However, to date, the data available on SGK-1 and aging, are sparse, controversial, and only from C. elegans experimental models. In this review we sought to discuss the possible implication of SGK-1 in mechanisms regulating senescence and age-related diseases. Moreover, we aimed to discuss and identify the possible role of SGK-1 as possible molecular target to counteract and prevent aging.


Assuntos
Envelhecimento , Doenças Cardiovasculares/enzimologia , Proteínas Imediatamente Precoces/metabolismo , Terapia de Alvo Molecular , Neoplasias/enzimologia , Transtornos Neurocognitivos/enzimologia , Proteínas Serina-Treonina Quinases/metabolismo , Animais , Doenças Cardiovasculares/tratamento farmacológico , Doenças Cardiovasculares/metabolismo , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Transtornos Neurocognitivos/tratamento farmacológico , Transtornos Neurocognitivos/metabolismo
3.
Ann Oncol ; 24(10): 2571-2575, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23852308

RESUMO

BACKGROUND: TNF-α has been proposed as a predictive factor for venous thromboembolism (VTE). Genetic polymorphisms could regulate TNF-α production. However, the relationship between TNFA gene variants and VTE is not clarified. This study aims to investigate the predictive role of five different TNFA gene promoter SNPs, or their haplotype combination(s), for a first VTE episode in gastrointestinal cancer out-patients treated with chemotherapy. PATIENTS AND METHODS: Serum TNF-α levels and TNFA -863C/A, -857C/T, -376G/A, -308G/A and -238G/A gene promoter polymorphisms were retrospectively evaluated in 314 subjects, including 157 controls and 157 Caucasian patients with histologically diagnosed GI cancers beginning chemotherapy delivery (5-fluorouracil either as monotherapy or in combination with platinum compounds or irinotecan). RESULTS: Haplotype analysis showed that a five-loci haplotype (CTGGG haplotype) has higher frequency in GI cancer patients who developed VTE (n = 15) during chemotherapy [odds ratio = 2.7, 95% confidence interval (CI) 1.04-7.11, P = 0.04]. GI patients who remained VTE-free did not differ in CTGGG haplotype frequency from controls. No association was observed between serum TNF-α levels and TNFA haplotype, but both were independent predictors of VTE. Approximately 20% of GI cancer patients carrying the CTGGG haplotype developed VTE compared with 4% of the remaining 101 patients (hazard ratio = 5.6, 95% CI 1.8-17.6, P = 0.003). CONCLUSION: These results suggest that TNFA might represent a candidate gene contributing to VTE pathogenesis in GI cancer patients and suggest that VTE risk during chemotherapy might be genetically identified. Validation studies are needed for translation into clinical practice.


Assuntos
Neoplasias Gastrointestinais/tratamento farmacológico , Fator de Necrose Tumoral alfa/genética , Tromboembolia Venosa/induzido quimicamente , Tromboembolia Venosa/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Antimetabólitos Antineoplásicos/efeitos adversos , Antimetabólitos Antineoplásicos/uso terapêutico , Antineoplásicos Fitogênicos/efeitos adversos , Antineoplásicos Fitogênicos/uso terapêutico , Camptotecina/efeitos adversos , Camptotecina/análogos & derivados , Camptotecina/uso terapêutico , Estudos de Casos e Controles , Feminino , Fluoruracila/efeitos adversos , Fluoruracila/uso terapêutico , Predisposição Genética para Doença , Haplótipos/genética , Humanos , Irinotecano , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas/genética , Estudos Retrospectivos , Risco , Fator de Necrose Tumoral alfa/sangue
4.
Pharmacogenomics J ; 12(4): 277-86, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22760589

RESUMO

The goal of cancer pharmacogenomics is to obtain benefit from personalized approaches of cancer treatment and prevention. Recent advances in genomic research have shed light on the crucial role of genetic variants, mainly involving genes encoding drug-metabolizing enzymes, drug transporters and targets, in driving different treatment responses among individuals, in terms of therapeutic efficacy and safety. Although a considerable amount of new targeted agents have been designed based on a finely understanding of molecular alterations in cancer, a wide gap between pharmacogenomic knowledge and clinical application still persists. This review focuses on the relevance of mutational analyses in predicting individual response to antitumor therapy, in order to improve the translational impact of genetic information on clinical practice.


Assuntos
Genômica , Terapia de Alvo Molecular/métodos , Neoplasias/tratamento farmacológico , Preparações Farmacêuticas , Farmacogenética , Biomarcadores Tumorais/genética , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Análise Mutacional de DNA , Receptores ErbB/genética , Receptores ErbB/fisiologia , Tumores do Estroma Gastrointestinal/genética , Genes ras/genética , Humanos , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/uso terapêutico , Transdução de Sinais
5.
Cardiovasc Drugs Ther ; 26(4): 301-9, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22527619

RESUMO

PURPOSE: Dyslipidemia is common in type 2 diabetes (T2D) and contributes to cardiovascular disease (CVD) by exacerbating atherosclerosis and hypercoagulability. Statins can stabilize atherosclerotic plaque and reduce prothrombotic status. In the present study we aimed to evaluate the coagulation activity and the effect of statins on procoagulant state of T2D patients using a novel activated protein C (APC)-dependent thrombin-generation assay. METHODS: Procoagulant status (by HemosIL ThromboPath (ThP) assay) and in vivo platelet activation (by plasma soluble (s)CD40L levels) were analyzed in a retrospective, cross-sectional study of 198 patients with long-standing T2D and 198 controls. RESULTS: Procoagulant status of T2D patients was enhanced when compared to control subjects (p < 0.0001). Similarly, sCD40L levels were increased in T2D (p < 0.0001). When testing ThP as the dependent variable in a multivariate regression model, sCD40L (p < 0.0001) and statin treatment (p = 0.019) were independent predictors of the procoagulant state of T2D patients. Subgroup analysis showed a significant improvement of coagulability in T2D patients on statins (p = 0.012). CONCLUSIONS: The use of a standardized, easy-to-run, and commercially available APC-dependent thrombin-generation assay detected the presence of a procoagulant status in a large series of patients with long-standing T2D and demonstrated a significant impact of statins in the coagulation status of patients with T2D.


Assuntos
Coagulação Sanguínea/efeitos dos fármacos , Diabetes Mellitus Tipo 2/sangue , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Trombina/química , Idoso , Ligante de CD40/sangue , Estudos Transversais , Diabetes Mellitus Tipo 2/metabolismo , Feminino , Humanos , Masculino , Ativação Plaquetária/efeitos dos fármacos , Proteína C/metabolismo , Estudos Retrospectivos
8.
Anticancer Res ; 29(10): 4131-8, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19846961

RESUMO

BACKGROUND: Homocysteinemia has been associated with oncogenic risk. This study was designed to investigate the homocysteine (Hcy) genotype/phenotype interactions together with the inflammatory and nutritional status of cancer patients. PATIENTS AND METHODS: The Hcy levels were analyzed in 47 cancer patients in association with methylenetetrahydrofolate reductase (MTHFR) polymorphisms, folate and inflammatory markers. RESULTS: The MTHFR C677T and A1298C genotype distributions did not differ from those predicted by the Hardy-Weinberg distribution. Conversely, the Hcy levels were higher in the cancer patients (p=0.04), who were also characterized by low-grade inflammation. The Hcy levels correlated with the interleukin-6 (IL-6) (p=0.001), tumor necrosis factor-alpha (TNF-alpha) (p=0.042) and folate (p<0.0001) levels of the patients. Multivariate analysis showed that TNF-alpha (p=0.014) and folate (p=0.019) were independent predictors of elevated Hcy levels in the cancer patients. CONCLUSION: The MTHFR polymorphisms do not significantly contribute to tHcy (total Hcy) levels in cancer patients, and cancer-related inflammation may be associated with elevated tHcy levels, possibly involving a TNF-alpha mediated pathway.


Assuntos
Neoplasias da Mama/sangue , Neoplasias Colorretais/sangue , Homocisteína/sangue , Adulto , Neoplasias da Mama/enzimologia , Neoplasias da Mama/genética , Estudos de Casos e Controles , Neoplasias Colorretais/enzimologia , Neoplasias Colorretais/genética , Feminino , Ácido Fólico/sangue , Humanos , Mediadores da Inflamação/sangue , Masculino , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Pessoa de Meia-Idade , Estado Nutricional , Polimorfismo de Nucleotídeo Único
9.
Clin Ter ; 157(3): 283-99, 2006.
Artigo em Italiano | MEDLINE | ID: mdl-16900856

RESUMO

Treatment of gastrointestinal stromal tumors (GIST) has been revolutioned by the recently discovered molecular mechanism responsible for the oncogenesis of this disease. In addition, due to the rapid progress at molecular and clinical level observed in the last few years, there is a need to review the current state of the art in order to delineate appropriate guidelines for the optimal management of these tumors. A panel of experts from several specialities, including medical oncology, surgery, pathology, molecular biology and imaging, were invited to participate in a meeting to present and discuss a number of pre-selected questions, and to achieve a consensus according to the categories of the National Comprehensive Cancer Network (NCCN) and the Standard Options Recommandations (SOR) of the French Federation of Cancer Centers. Generally, consensus points were from categories 2A of the NCCN and B2 of the SOR. Conventional histologic examination with immunohistochemistry for CD117, CD34, SMA, S-100 and desmin is considered standard. Molecular analysis for the identification of KIT and PDGFRA mutation may be indicated in CD117-negative GIST. Complete tumor resection with negative margins is the optimal surgical treatment. Adjuvant imatinib should be considered an experimental approach. Neoadjuvant imatinib is also experimental, although its use may be justified in unresectable or marginally resectable GIST. Imatinib should be started in metastatic or recurrent disease, and should be continued until progressive disease or drug intolerance. In these cases, sunitinib can be used. The optimal criteria for the assessment and monitoring of GIST undergoing imatinib therapy are not well known, but they should include reduction in tumor size and disease stabilization, as well as reduction of tumor density on CT scan and metabolic activity on PET scan.


Assuntos
Tumores do Estroma Gastrointestinal/diagnóstico , Tumores do Estroma Gastrointestinal/terapia , Antineoplásicos/uso terapêutico , Benzamidas , Terapia Combinada , Árvores de Decisões , Progressão da Doença , Humanos , Mesilato de Imatinib , Recidiva Local de Neoplasia , Piperazinas/uso terapêutico , Guias de Prática Clínica como Assunto , Pirimidinas/uso terapêutico
12.
Int J Biol Markers ; 18(1): 21-7, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12699059

RESUMO

To date no general agreement has been reached regarding the prognostic significance of CEA, CA 19-9 and CA 72-4 as serum markers in gastric cancer, and only scattered information is available on the predictive value of marker expression in tumor tissue. Therefore, a longitudinal study was designed to analyze the presurgical serum and tumor tissue content of CA 72-4, CEA and CA 19-9 in 166 patients at different stages of gastric cancer, and to evaluate the possible correlation with clinicopathological features in respect to prognostic information on relapse-free survival. The results obtained showed that 48.4% of patients with tumor recurrence had positive presurgical CA 72-4 levels compared to approximately 24% of patients who remained free of disease. Furthermore, the median presurgical serum CA 72-4 levels were significantly elevated in relapsing patients. Serosa and lymph node involvement as well as positive presurgical serum CA 72-4 levels had independent prognostic value in predicting recurrence. A significant association between disease-free survival and lymph node involvement, depth of invasion and tumor tissue content of CA 72-4 was also demonstrated. We may therefore conclude that CA 72-4 antigen can be considered the marker of choice in the follow-up of gastric cancer patients and may be used as a prognostic indicator of relapse.


Assuntos
Antígenos Glicosídicos Associados a Tumores/biossíntese , Neoplasias Gástricas/diagnóstico , Neoplasias Gástricas/metabolismo , Adulto , Idoso , Biomarcadores Tumorais/metabolismo , Intervalo Livre de Doença , Feminino , Humanos , Metástase Linfática , Masculino , Prognóstico , Neoplasias Gástricas/patologia , Fatores de Tempo
13.
J Hum Evol ; 41(3): 211-25, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11535000

RESUMO

Castel di Guido near Rome is one of the few open air Middle Pleistocene European sites that has yielded hominid skeletal remains associated with fossil fauna and Acheulean implements. The fossil hominid bones include two femoral shafts, respectively designated Castel di Guido-1 (CdG-1) and CdG-2, an occipital fragment (CdG-3), a right maxilla lacking teeth (CdG-4), a portion of right parietal (CdG-5), a right temporal (CdG-6), and a fragment of left parietal vault (CdG-7). CdG-1 through CdG-4 were collected in 1979-1982 on the surface, together with fossil fauna, where ploughing incised fossiliferous tuffaceous sands. Excavations conducted in the same area from 1980 to 1990 led to the discovery of CdG-5, CdG-6 and CdG-7 within the tuffaceous sands, which were shown to overlay a bone-bearing paleosurface, with abundant evidence of hominid activities. The Castel di Guido hominid assemblage poses intriguing taphonomic questions. The analysis of the physical evidence offered by the bone surfaces, reported in the present study, indicates that the hominid skeletal remains were heavily fragmented before fossilization and exposed to carnivores and rodents, as well as to trampling and/or friction in abrasive sediment. Although definitive conclusions cannot be reached on the basis of the available evidence, it is possible that clusters of incisions localized on specific regions of the Castel di Guido fossil hominid bones might reflect deliberate human manipulations.


Assuntos
Antropologia Cultural , Fêmur/anatomia & histologia , Fósseis , Hominidae/anatomia & histologia , Crânio/anatomia & histologia , Animais , Rituais Fúnebres , Humanos , Itália , Microscopia Eletrônica de Varredura
14.
Cancer Res ; 61(14): 5415-9, 2001 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-11454685

RESUMO

Microsatellite instability (MSI) occurs frequently in sporadic gastric cancer (GC) and may define a distinctive molecular pathway of carcinogenesis. We evaluated the role of dietary risk factors in GC according to MSI status. A large series of 382 GC cases and 561 controls were originally identified in a population-based case-control study carried out in the high-risk area around Florence, Italy; 126 GC patients were typed for MSI status. A MSI+ phenotype was detected in 43 of 126 cases (34.1%), whereas 83 cases were classified as MSI-. A multinomial logistic regression model was used to compare the two subgroups of GC classified according to MSI status in the same analysis, with all of the available population controls. A case-case approach was also used. The risk of MSI+ tumors was positively associated with high consumption of red meat and meat sauce and negatively associated with consumption of white meat. A positive association was also seen with total protein and nitrite intake, whereas no relation was found with micronutrient intake. Risk was especially high among subjects reporting both a positive GC family history and a high consumption of red meat (odds ratio, 25.7; 95% confidence interval, 6.4-102.8). For MSI- tumors, a significant protective effect was associated with frequent consumption of citrus and other fresh fruit, garlic, legumes, vegetables, and olive oil and with high intake of beta-carotene and other antioxidants and sugar, whereas positive associations were seen with protein and sodium intake. In summary, a specific dietary pattern emerged for MSI+ gastric tumors, suggesting that factors related to red meat consumption are involved in this pathway, particularly among individuals with a positive family history. In contrast, the risk of MSI- tumors was strongly reduced by the frequent consumption of fresh fruit and vegetables.


Assuntos
Carne , Repetições de Microssatélites/genética , Neoplasias Gástricas/genética , Idoso , Animais , Estudos de Casos e Controles , Dieta , Proteínas Alimentares/administração & dosagem , Saúde da Família , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Neoplasias Gástricas/etiologia
15.
Hum Mol Genet ; 9(17): 2517-21, 2000 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-11030756

RESUMO

The insulin receptor substrate-2 (IRS-2) is a major insulin signalling molecule. IRS-2 inactivation in mice induces a form of diabetes characterized by peripheral insulin resistance and reduced beta cell mass. We tested the hypothesis that a common non-conservative amino acid substitution of IRS-2 (G1057D) might interact with overweight in the pathogenesis of type 2 diabetes. The variant was genotyped in 193 Italian patients with type 2 diabetes and 206 control subjects. In the absence of overweight, the risk of type 2 diabetes decreased according to the dosage of the D1057 allele (odds ratio for GD genotype 0.46 [95% CI 0.25-0.86]; DD genotype 0.18 [0.04-0.68]; P for trend = 0.0012). Conversely, the interaction between overweight and genotype increased the risk of type 2 diabetes according to the dosage of the D1057 allele (odds ratio for GD genotype 2.50 [1.11-5.65]; DD genotype 5.74 [1.11-29. 78]; P for trend = 0.0047). Among controls, fasting C-peptide levels, after adjustment for plasma glucose, were inversely related to the dosage of the D1057 allele (P = 0.020). This finding suggested that carriers of the D1057 allele may have higher insulin sensitivity and supported the protective effect of this allele. Conversely, among overweight patients there was a parallel increase in fasting plasma glucose (P for trend = 0.037) and fasting C-peptide according to the dosage of the D1057 allele, suggesting that higher insulin resistance and relative beta cell failure contributed to the increased risk of type 2 diabetes in overweight carriers of this allele. These data provide evidence for a strong association between type 2 diabetes and the G1057D common genetic variant of IRS-2, which appears to be protective against type 2 diabetes in a codominant fashion. Overweight appears to modify the effect of this polymorphism toward a higher risk of type 2 diabetes. Carriers of this polymorphism may represent an elective target for prevention of type 2 diabetes through preventing or treating excessive weight.


Assuntos
Diabetes Mellitus Tipo 2/etiologia , Diabetes Mellitus Tipo 2/genética , Variação Genética , Obesidade/complicações , Fosfoproteínas/genética , Adulto , Idoso , Alelos , Glicemia/metabolismo , Índice de Massa Corporal , Peptídeo C/sangue , Estudos de Casos e Controles , Feminino , Dosagem de Genes , Predisposição Genética para Doença , Genótipo , Humanos , Proteínas Substratos do Receptor de Insulina , Peptídeos e Proteínas de Sinalização Intracelular , Masculino , Pessoa de Meia-Idade , Razão de Chances , Polimorfismo Genético , Análise de Regressão
16.
Int J Mol Med ; 6(1): 97-9, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10851274

RESUMO

Peripheral blood DNA from 12 subjects affected by familial obesity and from 35 subjects affected by type 2 diabetes were analysed for mutations in the coding sequence of the OB gene. Mutational analysis, conducted using the single strand conformation polymorphism (SSCP) technique, followed by direct sequencing did not reveal the presence of nucleotide variants in the coding region of the OB gene. The lack of mutations in the coding sequence is consistent with previous data suggesting that mutations in the coding sequence of the OB gene are not common in human familial obesity. In 2 samples displaying a non-informative pattern of SSCP and in 8 additional samples the nucleotide sequence of portion of the intron 2 bordering the coding sequence of exon 2 identified a G in the positions +14IVS and +18IVS, according to a sequence reported previously, but in contrast with some others. All samples were homozygous for these intron variants.


Assuntos
Diabetes Mellitus Tipo 2/genética , Leptina/genética , Obesidade/genética , Adulto , Idoso , Análise Mutacional de DNA , Diabetes Mellitus/genética , Feminino , Humanos , Íntrons , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Polimorfismo Conformacional de Fita Simples
17.
Br J Cancer ; 82(2): 348-53, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10646887

RESUMO

Correlations between germline APC mutation sites and colorectal pathophenotypes, as evaluated by the direct count of adenomas at colectomy, were investigated analysing colectomy specimens from 29 FAP patients carrying one mis-sense (codon 208) and 14 frame-shift or non-sense APC mutations (codons 232, 367, 437, 623, 876, 995, 1061, 1068, 1075, 1112, 1114, 1309, 1324, 1556). The mis-sense mutation at codon 208 was associated with a relatively mild colorectal pathophenotype. The mutation at codon 367, subject to alternative splicing, was associated with attenuated FAP. The mutation at codon 1309 was associated with the profuse colorectal adenomatosis. For 13 mutations, predicted to result in null alleles or truncated APC proteins, we correlated density and distribution of colorectal adenomas with the predicted functional effects of the mutation. The most severe colorectal pathophenotype was significantly associated with the truncating mutation at codon 1309, which is located downstream to the I beta-catenin binding domain but upstream II beta-catenin-binding domain. Mutations between codons 867 and 1114, which affect the I beta-catenin binding domain, as well as mutations occurring in exons 6 and 9, predicted to result in null alleles, were associated with a less severe colorectal pathophenotype. Overall, the highest number of adenomas was detected in the right colon, followed by the left colon, transverse colon sigma and rectum. However, the highest density of adenomas was observed in the left colon, followed by the right colon, sigma, transverse colon and rectum. Colorectal carcinomas, observed in only five patients, were all in the left colon.


Assuntos
Adenoma/genética , Polipose Adenomatosa do Colo/genética , Neoplasias Colorretais/genética , Genes APC/genética , Mutação em Linhagem Germinativa/genética , Adenoma/etiologia , Adenoma/patologia , Polipose Adenomatosa do Colo/patologia , Adolescente , Adulto , Criança , Neoplasias Colorretais/etiologia , Neoplasias Colorretais/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo
18.
Cancer Res ; 59(15): 3570-5, 1999 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-10446963

RESUMO

We analyzed the hMLH1 and hMSH2 genes in 30 unrelated hereditary nonpolyposis colorectal cancer (HNPCC) patients using mutational and immunohistochemical analyses combined whenever possible with primer extension assays, designed to estimate hMLH1 and hMSH2 transcript expression in peripheral blood lymphocytes. Single-strand conformational polymorphism screening and PCR-direct sequencing revealed seven hMLH1 and five hMSH2 sequence variants in 14 unrelated HNPCC patients, including three definite pathogenic mutations, four amino acid substitutions of uncertain pathogenic significance, and five polymorphisms. Immunohistochemistry indicated the lack of either hMLH1 or hMSH2 protein expression in tumors from 13 patients, and the absence of both hMLH1 and hMSH2 immunostaining was observed in the tumor from one additional case. The lack of hMLH1 or hMSH2 immunostaining was associated with the presence of microsatellite instability in the corresponding tumor and was also observed in tumors from patients negative for pathogenic mutations by mutational screening. There was a marked unbalance in the allelic expression of either hMLH1 or hMSH2 transcripts in three of eight unrelated HNPCC patients that could be analyzed, although a less marked unbalance was detected in two additional patients. Tumors from patients with germ-line unbalance in hMLH1 or hMSH2 transcript expression did not express the corresponding mismatch repair protein and displayed microsatellite instability. Our results indicate that constitutional alterations in hMLH1 and hMSH2 transcript expression may represent genetic markers for HNPCC carrier status also in cases in which mutational analysis did not detect a definite pathogenic variant. This suggests that transcript deregulation may represent a relevant mode of germ-line inactivation for mismatch repair genes.


Assuntos
Neoplasias Colorretais Hereditárias sem Polipose/genética , Reparo do DNA/genética , Proteínas de Ligação a DNA , Regulação Neoplásica da Expressão Gênica , Proteínas de Neoplasias/biossíntese , Proteínas Proto-Oncogênicas/biossíntese , Proteínas Adaptadoras de Transdução de Sinal , Alelos , Proteínas de Transporte , Neoplasias Colorretais Hereditárias sem Polipose/metabolismo , Análise Mutacional de DNA , Heterogeneidade Genética , Marcadores Genéticos , Predisposição Genética para Doença , Humanos , Linfócitos/metabolismo , Repetições de Microssatélites , Proteína 1 Homóloga a MutL , Proteína 2 Homóloga a MutS , Proteínas de Neoplasias/genética , Proteínas Nucleares , Mutação Puntual , Reação em Cadeia da Polimerase , Polimorfismo Conformacional de Fita Simples , Proteínas Proto-Oncogênicas/genética , RNA Mensageiro/biossíntese , RNA Neoplásico/biossíntese , Deleção de Sequência , Transcrição Gênica
19.
Br J Cancer ; 79(2): 340-5, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9888478

RESUMO

Fifty-one thyroid tumours and tumour-like lesions were analysed for instability at ten dinucleotide microsatellite loci and at two coding mononucleotide repeats within the transforming growth factor beta (TGF-beta) type II receptor (TbetaRII) and insulin-like growth factor II (IGF-II) receptor (IGFIIR) genes respectively. Microsatellite instability (MI) was detected in 11 out of 51 cases (21.5%), including six (11.7%) with MI at one or two loci and five (9.8%) with MI at three or more loci (RER+ phenotype). No mutations in the TbetaRII and IGFIIR repeats were observed. The overall frequency of MI did not significantly vary in relation to age, gender, benign versus malignant status and tumour size. However, widespread MI was significantly more frequent in follicular adenomas and carcinomas than in papillary and Hürthle cell tumours: three out of nine tumours of follicular type (33.3%) resulted in replication error positive (RER+), versus 1 out of 29 papillary carcinomas (3.4%, P = 0.01), and zero out of eight Hürthle cell neoplasms. Regional lymph node metastases were present in five MI-negative primary cancers and resulted in MI-positive in two cases.


Assuntos
Repetições de Microssatélites/genética , Neoplasias da Glândula Tireoide/genética , Adenocarcinoma Folicular/genética , Adenocarcinoma Folicular/patologia , Adenoma/genética , Adenoma/patologia , Idoso , Carcinoma Papilar/genética , Carcinoma Papilar/patologia , Replicação do DNA , Feminino , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Neoplasias da Glândula Tireoide/patologia
20.
Eur J Cancer ; 34(6): 927-30, 1998 May.
Artigo em Inglês | MEDLINE | ID: mdl-9797709

RESUMO

Germline mutations of the hMLH1 gene are estimated to account for a large fraction of kindreds affected by hereditary non-polyposis colorectal cancer (HNPCC). In a significant number of cases, hMLH1 mutations result in the expression of truncated proteins. We report here two novel alternatively spliced forms of hMLH1 mRNA in normal lymphocytes. One of these novel isoforms lacks the coding region of the gene between codons 557 and 578, corresponding to the entire exon 15. The deletion introduces a frameshift that results in a premature stop signal. The other isoform is characterised by an in-frame deletion spanning codons 578-632, corresponding to loss of the entire exon 16. Further studies are necessary to establish the biological significance of these alternative splicings. The presence of alternatively spliced hMLH1 transcripts that mimic pathogenic mutations should be taken into account in the mutational screening of the hMLH1 gene by reverse transcription-polymerase chain reaction methodologies.


Assuntos
Neoplasias Colorretais Hereditárias sem Polipose/genética , Mutação , Proteínas de Neoplasias/genética , Proteínas Adaptadoras de Transdução de Sinal , Processamento Alternativo , Proteínas de Transporte , Éxons , Humanos , Linfócitos/patologia , Proteína 1 Homóloga a MutL , Proteínas Nucleares , Reação em Cadeia da Polimerase , Análise de Sequência
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