Investigation of clinical utility of ATM and PTEN genes in the differentiated thyroid cancer

Orientador: Laura Sterian WardTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias MedicasResumo: Para investigar a utilidade clínica de dois genes supressores tumorais envolvidos no controle da proliferação e sobrevivência celular, nós estudamos por imunoistoquímica as proteínas ATM e PTEN em 272 pacientes diagnosticados carcinoma diferenciado da tireóide (142 carcinomas papilíferos do tipo clássico, 72 carcinomas papilíferos variante folicular, 17 carcinomas papilíferos de células altas e 41 carcinomas foliculares); 106 amostras de tecido de pacientes diagnosticados com doenças tiroidianas benignas (55 adenomas foliculares e 51 com bócio), 18 tecidos de tiróide normal extraídos de lobo contra-lateral de indivíduos operados por adenoma folicular. A expressão quantitativa de ATM foi avaliada por Real-Time PCR em 87 CP. Ainda, analisamos o perfil genotípico para três polimorfismos de ATM (D1853N, S707P e S49C) em 199 pacientes (164 carcinomas papilíferos e 35 carcinomas foliculares) e 219 indivíduos controles. Os pacientes foram seguidos por 53,8±41 meses utilizando-se um protocolo padrão. 179 pacientes foram classificados como livre de doença e 48 pacientes tiveram má evolução (recidivas e 12 mortes). A análise da regressão logística múltipla ajustada para sexo e faixa etária mostrou que a expressão da proteína ATM foi mais freqüente entre os pacientes que apresentavam tumores menos agressivos (81%) e que evoluíam livres de doença (63%) (p=0.016; p=0.0276 respectivamente). Maior incidência de casos que expressavam a proteína PTEN também foi observada em pacientes que não tiveram metástase na evolução (75%) (p= 0.0437). O alelo heterozigoto para o polimorfismo D1853N de ATM foi mais prevalente entre os controles (64%) do que nos indivíduos com câncer (36%) (p=0.0364) Estes dados indicam que ATM e PTEN podem ser úteis na identificação de agressividade e na classificação de prognóstico do CDT.Abstract: In order to investigate the clinical utility of two tumor-suppressing genes involved in the control of cell proliferation and survival, we've studied proteins ATM and PTEN through immunohistochemistry in 272 differentiated thyroid carcinoma diagnosed patients (142 classical papillary thyroid carcinomas type, 72 papillary thyroid carcinomas follicular variant, 17 papillary thyroid carcinomas tall cells variant and 41 follicular carcinomas), 106 tissue samples from patients diagnosed with benign thyroid diseases (55 follicular thyroid adenomas and 51 with goiter), 18 normal thyroid tissue samples extracted from the counter lateral lobe of individuals operated for follicular thyroid adenomas. The quantitative expression of ATM gene was available for Real-Time PCR in 87 papillary carcinomas. In order to analyze the genotypic profile, we've also studied three ATM polymorphisms (D1853N, S707P e S49C) in 199 patients (164 papillary carcinomas and 35 follicular carcinomas) and 219 control individuals. Patients were accompanied for 53,8±41 months, using a standard protocol. 179 patients were tagged as disease-free and 48 patients had bad outcome (12 deaths). The analysis of multiple logistic regression adjusted for gender and age has showed that the ATM protein expression was more frequent among patients that didn't have metastasis when diagnosed (81%) and that were free of disease (63%) (p=0.016; p=0.0276 respectively). The major incidence of cases who expression PTEN protein, also was observed in patients that didn't have metastasis during follow- up (75%) (p= 0.0437). The heterozygous alleles for D1853N polymorphism was more prevailing among the controls (64%) than in individuals with cancer (36%) (p=0.0364). Nevertheless these results demonstrated that ATM and PTEN protein expression can be useful in identifying patients with aggressiveness and the classification of prognosis in differentiated thyroid carcinoma.DoutoradoClinica MedicaDoutor em Clínica Médic

Identifying A Risk Profile For Thyroid Cancer.

The large use of simple and effective diagnostic tools has significantly contributed to the increase in diagnosis of thyroid cancer over the past years. However, there is compelling evidence that most micropapillary carcinomas have an indolent behavior and may never evolve into clinical cancers. Therefore, there is an urgent need for new tools able to predict which thyroid cancers will remain silent, and which thyroid cancers will present an aggressive behavior. There are a number of well-established clinical predictors of malignancy and recent studies have suggested that some of the patients laboratory data and image methods may be useful. Molecular markers have also been increasingly tested and some of them appear to be very promising, such as BRAF, a few GST genes and p53 polymorphisms. In addition, modern tools, such as immunocytochemical markers, and the measure of the fractal nature of chromatin organization may increase the specificity of the pathological diagnosis of malignancy and help ascertain the prognosis. Guidelines designed to select nodules for further evaluation, as well as new methods aimed at distinguishing carcinomas of higher aggressiveness among the usually indolent thyroid tumors are an utmost necessity.51713-2

N-acetiltransferase-2 gene polymorphisms and the susceptibility to prostate and thyroid cancers in Brazilian patients

Orientador: Laura Sterian WardDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias MedicasResumo: Os genes das N-acetiltransferases, que são polimórficos na população, codificam enzimas envolvidas na metabolização de drogas e de xenobióticos, como os provenientes do cozimento de carnes e do tabaco, e podem estar implicados no risco para o desenvolvimento de neoplasias. Para estudar o envolvimento dos genes NAT2 em tumores na população brasileira da região de Campinas, avaliamos seis polimorfismos (C282T; T481C; G590A; A803G; G857A; G191A) em câncer de tireóide e quatro (T481C; G590A; A803G e G857A) em câncer de próstata. Em um estudo de caso-controle, comparamos 126 indivíduos com câncer de próstata com 101 indivíduos controles com hiperplasia prostática benigna pareados para idade e condições de dieta e exposição ambiental; 139 indivíduos com câncer de tireóide (112 CP e 27CF) e 179 controles também adequadamente pareados. A análise foi feita pela extração de DNA com base no sangue periférico, PCR e restrição enzimática. Os polimorfismos T481C (76.24%) e A803G (59.41%) apareceram com maior freqüência entre os pacientes controles com hiperplasia prostática benigna do que nos com câncer da próstata (60.32% e 45.60%, p=0.0152 e 0.0186, respectivamente). Ao contrário, G857A foi mais freqüente entre os pacientes com câncer da próstata (18.4%) do que nos controles com hiperplasia prostática benigna (5.94%; p=0.0044). Assim, a presença do polimorfismo NAT2T481C reduziu o risco de câncer da próstata (OR=2.115; 95% C.I=1.155-3.872). Da mesma forma, a presença do polimorfismo NAT2A803G reduziu o risco de câncer da próstata (OR=1.973; 95%C.I=1.120-3.474; p=0.0186). Ao contrário, a presença do polimorfismo G857A aumentou o risco para câncer da próstata mais de quatro vezes (OR=4.095; 95%C.I=1.551-10.812). A presença de um fenótipo de acetilação lenta aumentou o risco para câncer de próstata em 24 vezes (OR=24.145;95%CI=1.416-411.63). Nos carcinomas da tireóide, observamos que mutações pontuais de tipo A803G apareceram com maior freqüência entre os casos de carcinomas (46.76%) do que nos controles (31.84%) (p=0.0069), enquanto que mutações pontuais de tipo G191A e C282T foram mais freqüentes nos controles (25,70% e 68.16% dos casos, respectivamente) do que nos casos (5,04% e 33,81%, respectivamente) (p=0,0001). Assim, a herança do polimorfismo A803G representou um risco de 1.8 vezes maior de desenvolver carcinoma diferenciado da tireóide (OR= 1.880; 95% IC= 1.189-2.973). Por outro lado, a herança dos polimorfismos G191A e C282T do gene NAT2 representou um fator de proteção de cerca de 80,6% contra o risco de desenvolver um carcinoma diferenciado da tireóide (OR=0.153; 95% IC=0.067-0.352 e OR=0.239; 95% IC=0.149-0.382, respectivamente). Em conclusão, nossos dados mostram que polimorfismos do gene NAT2 estão associados ao risco para o desenvolvimento tanto dos tumores de próstata quanto de tireóide, podendo vir a ser importantes marcadores de susceptibilidade para tais doenças em nossa populaçãoAbstract: N-acetyltransferases (NAT), which are polymorphic in the population, metabolize important carcinogens such as different kinds of meat and tobacco products that have been directly implicated in the tumor initiation process. In order to investigate the role of NAT2 polymorphisms in the susceptibility to cancer in the Brazilian population from our region, we studied 6 polymorphisms (C282T; T481C; G590A; A803G; G857A; G191A) in differentiated thyroid cancer and 4 polymorphisms (T481C; G590A; A803G e G857A) in prostate cancer. We conducted a case-control prospective study comparing 126 prostate cancer to 101 benign prostatic hyperplasia patients paired for age, diet and environmental exposure; 139 thyroid cancer patients (112 papillary carcinomas and 27 follicular carcinomas) and 179 paired controls. Analyses were performed in DNA extracted from peripheral blood using the polymerase chain reaction-based restriction fragment length polymorphism method. We observed T481C (76.24%) and A803G (59.41%) polymorphisms with higher frequency among control patients than in prostate cancer cases (60.32% e 45.60%, p=0.0152 e 0.0186, respectively). On the contrary, G857A polymorphisms was more frequent among prostate cancer patients (18.4%) than in the benign hyperplasia control partients¿ group (5.94%; p=0.0044). Therefore, the presence of NAT2T481C polymorphism reduced the risk of prostate cancer (OR=2.115; 95% C.I=1.155-3.872). Likewise, the presence of NAT2A803G reduced the risk of prostate cancer (OR=1.973; 95%C.I=1.120-3.474; p=0.0186). On the contrary, the presence of G857A increased the risk for prostate cancer more than 4 times (OR=4.095; 95%C.I=1.551-10.812). The presence of a low acetylation phenotype increased the risk for prostate cancer more than 24 times (OR=24.145;95%CI=1.416-411.63). Regarding thyroid cancer, we observed that point mutations like A803G appears more frequently among thyroid carcinomas (46.76%) than in controls (31.84%) (p=0.0069), while G191A and C282T polymorphisms were more frequent among controls (25,70% and 68.16% of the cases, respectively) than among thyroid cancers (5,04% e 33,81%, respectively) (p=0,0001). Therefore, the inheritance of an A803G polymorphism represents an 1.8 times higher risk to thyroid cancer development (OR= 1.880; 95% IC= 1.189-2.973). On the other hand, the inheritance of G191A and C282T NAT2 polymorphisms represents a protection around 80,6% against the risk of thyroid cancer development (OR=0.153; 95% IC=0.067-0.352 and OR=0.239; 95% IC=0.149-0.382, respectively). In conclusion, our data demonstrate that NAT2 gene polymorphisms are associated to the risk to both prostate and thyroid cancer, suggesting they could become useful molecular markers of susceptibility to these tumors in our populationMestradoClinica MedicaMestre em Clinica Medic

The Role Of Tp53 Pro47ser And Arg72pro Single Nucleotide Polymorphisms In The Susceptibility To Bladder Cancer.

Several studies have investigated the association between TP53 Arg72Pro and an increased risk of developing bladder tumors, with controversial results. Taking advantage of the high admixture rates in the Brazilian population, we genotyped 94 bladder cancer patients (76 males and 18 females; aged 21-96 years old; 67 ± 13 years old; 79 smokers and 15 nonsmokers) carefully paired with 159 controls (104 males and 55 females; aged 20-100 years old; 65 ± 21 years old; 126 smokers and 33 nonsmokers) with respect to environmental exposure, diet routine, lifetime occupational history, smoking history, general health conditions, and previous diseases. Arg/Pro genotype was under-represented in the patient population, and conferred a 44% lower risk of bladder cancer. Univariate logistic regression analysis also identified male sex (OR=6.87, 95% CI=3.78-12.50; P<0.001), age over 65 years (OR=4.44, 95% CI=2.56-7.71; P<0.001), and smoking habits (OR=18.61, 95% CI=9.62-36.03; P<0.001) as important risk factors for bladder cancer. However, the TP53Arg72Pro genotype disappeared as a susceptibility factor both in the multivariate regression analysis and in a univariate regression analysis adjusted for gender, age, and smoking, suggesting that it was connected with one of these factors in the predisposition to bladder cancer. Indeed, a further analysis demonstrated that both alleles and genotype variants of TP53Arg72Pro are less frequent in older patients (P=0.029). We concluded that the effect of TP53Arg72Pro, described in some studies as an important risk factor, may not be an independent, but an age-related factor of susceptibility to bladder cancer.29291-

mRNA BRAF expression helps to identify papillary thyroid carcinomas in thyroid nodules independently of the presence of BRAFV600E mutation

Literature has consistently shown associations of BRAFV600E mutation with papillary thyroid cancer clinical features. However, the clinical utility of BRAF expression has not been clinically explored so far. We studied 67 thyroid nodules (32 benign nodules and 35 PTC cases). BRAF mRNA expression levels measured by a quantitative real-time PCR and a PCR-RFLP were used to identify BRAFV600E mutation. BRAF mRNA expression was significantly higher in malignant (198.2 +/- 373.9 AU) than in benign (4.1 +/- 6.9 AU) nodules (p < 0.0001). BRAF expression identified malignancy with a sensitivity of 80.6%, specificity of 77.1%, positive predictive value of 75.8%, and negative predictive value of 81.8%. A cut-point of 4.712, identified by the ROC curve, was able to sort out malignant nodules with an accuracy of 78.8%. Although we did not find any correlation between the presence of BRAF V600E mutation and clinical or tumor features such as age (p = 0.309), gender (p = 0.5453), ethnicity (p = 0.9820), tumor size (p = 1.000), multifocality (p = 0.2530) or mRNA levels (p = 0.7510), the study power for BRAF expression and diagnosis (99%; FPRP = 0.85) indicated that data is noteworthy despite the relative small number of patients investigated. We concluded that BRAF mRNA expression may help to identify PTC among thyroid nodules independently of the presence of BRAFV600E mutation. (C) 2012 Elsevier GmbH. All rights reserved.208848949

N-acetyltransferase-2 Gene Polymorphisms And Prostate Cancer Susceptibility In Latin American Patients.

We investigated the role of N-acetyltransferases (NAT) in prostate cancer (PCa) susceptibility. NAT are polymorphic in the population and metabolize important carcinogenic products directly involved in the tumor initiation process. This prospective case-control study utilized the polymerase chain reaction-based restriction fragment length polymorphism method and comprised a cohort of consecutive 478 individuals: 126 men with prostate cancer; 101 men with benign prostatic hyperplasia (BPH); and a control health population of 177 female and 74 male blood donors from the same region. NAT2 slow or fast acetylators genotypes were determined by the combination of four variant alleles. Lifetime occupational history, dietary patterns, cigarette smoking and other anamnestic data were obtained by interviews. We were not able to find any correlation among smoking, dietary patterns, parameters of tumor aggressiveness or patient outcome and any NAT2 genotypes or phenotypes considered in separate or in different combinations. However, there was an association between NAT2T481C (OR=0.47; 95% CI=0.26-0.84; P=0.01) and NAT2A803G (OR=0.57; 95% CI=0.33-0.97; P=0.04) polymorphisms and PCa protection. Conversely, the presence of NAT2G857A genotype increased the risk of PCa more than 3 times (OR=3.57; 95% CI=1.39-9.15; P=0.005). Slow acetylator NAT2*7A and NAT2*6B genotypes occurred in 10.31% of PCa but in none of BPH patients (P=0.0007). The control health population confirmed the results and allowed the exclusion of possible biases caused by gender influence on genotype inheritance and by the inclusion of not diagnosed prostate diseases patients among the control individuals. We suggest that the investigation of germline polymorphisms of NAT2 gene may be useful in the assessment of Latin American patients at risk of BPH and PCa.292889-9