Overexpression of NAT10 induced platinum drugs resistance in breast cancer cell / 中华肿瘤杂志

Objective: To observe the platinum drugs resistance effect of N-acetyltransferase 10 (NAT10) overexpression in breast cancer cell line and elucidate the underlining mechanisms. Methods: The experiment was divided into wild-type (MCF-7 wild-type cells without any treatment) group, NAT10 overexpression group (H-NAT10 plasmid transfected into MCF-7 cells) and NAT10 knockdown group (SH-NAT10 plasmid transfected into MCF-7 cells). The invasion was detected by Transwell array, the interaction between NAT10 and PARP1 was detected by co-immunoprecipitation. The impact of NAT10 overexpression or knockdown on the acetylation level of PARP1 and its half-life was also determined. Immunostaining and IP array were used to detect the recruitment of DNA damage repair protein by acetylated PARP1. Flow cytometry was used to detect the cell apoptosis. Results: Transwell invasion assay showed that the number of cell invasion was 483.00±46.90 in the NAT10 overexpression group, 469.00±40.50 in the NAT10 knockdown group, and 445.00±35.50 in the MCF-7 wild-type cells, and the differences were not statistically significant (P>0.05). In the presence of 10 μmol/L oxaliplatin, the number of cell invasion was 502.00±45.60 in the NAT10 overexpression group and 105.00±20.50 in the NAT10 knockdown group, both statistically significant (P<0.05) compared with 219.00±31.50 in wild-type cells. In the presence of 10 μmol/L oxaliplatin, NAT10 overexpression enhanced the binding of PARP1 to NAT10 compared with wild-type cells, whereas the use of the NAT10 inhibitor Remodelin inhibited the mutual binding of the two. Overexpression of NAT10 induced PARP1 acetylation followed by increased PARP1 binding to XRCC1, and knockdown of NAT10 expression reduced PARP1 binding to XRCC1. Overexpression of NAT10 enhanced PARP1 binding to LIG3, while knockdown of NAT10 expression decreased PARP1 binding to LIG3. In 10 μmol/L oxaliplatin-treated cells, the γH2AX expression level was 0.38±0.02 in NAT10 overexpressing cells and 1.36±0.15 in NAT10 knockdown cells, both statistically significant (P<0.05) compared with 1.00±0.00 in wild-type cells. In 10 μmol/L oxaliplatin treated cells, the apoptosis rate was (6.54±0.68)% in the NAT10 overexpression group and (12.98±2.54)% in the NAT10 knockdown group, both of which were statistically significant (P<0.05) compared with (9.67±0.37)% in wild-type cells. Conclusion: NAT10 overexpression enhances the binding of NAT10 to PARP1 and promotes the acetylation of PARP1, which in turn prolongs the half-life of PARP1, thus enhancing PARP1 recruitment of DNA damage repair related proteins to the damage sites, promoting DNA damage repair and ultimately the survival of breast cancer cells.

Influência da neoplasia mamária na concentração sérica de hormônios e na expressão de receptores de estrógeno e progesterona em cadelas / Influence of mammary neoplasm on the serum concentration of hormones and on the expression of estrogen and progesterone receptors in bitches

O objetivo desse estudo foi avaliar as concentrações séricas de estradiol, progesterona e prolactina, bem como a expressão gênica dos receptores de estrógeno α e β e de progesterona em cadelas com neoplasias mamárias. Foram utilizadas 60 cadelas adultas, sem raça definida que foram distribuídas em dois grupos. O Grupo I constituído por 30 cadelas portadoras de neoplasias mamárias e o Grupo II constituído por 30 cadelas saudáveis, não portadoras de neoplasia. Para os tutores, foram aplicados questionários sobre fatores epidemiológicos da doença. Após avaliação dos exames pré-operatórios, as cadelas com neoplasia mamária foram submetidas à mastectomia, coletaram-se fragmentos das neoplasias e linfonodos regionais, os quais foram processados para análise histopatológica. Para as dosagens hormonais de estradiol, progesterona e prolactina foram colhidas amostras de sangue em tubos sem anticoagulante e os soros foram submetidos à técnica de eletroquimioluminescência. A expressão gênica dos receptores hormonais foi realizada por meio da técnica de Real-time PCR e para isso foram coletados fragmentos das neoplasias mamárias e extraído o RNA para obtenção do cDNA. A expressão do mRNA para os REα, REβ e RP foi avaliada a partir da amplificação desses genes utilizando primers específicos. Verificaram-se maiores níveis séricos de estradiol (média de 38,98±13,68pg/mL) em cadelas portadoras de neoplasias mamárias malignas quando comparadas as cadelas do grupo controle (p<0,05). Já os níveis séricos de prolactina foram maiores (média de 0,231±0,201ng/mL) nas cadelas que não possuíam neoplasias mamárias quando comparadas ao Grupo I (p<0,05). Para os níveis de progesterona não foram observadas diferença entre os diferentes grupos (p>0,05). Tanto os tumores malignos como os benignos expressaram REα, REβ e RP, não havendo diferença (p>0,05) na expressão entre tumores malignos ou benignos ou relacionada aos outros fatores prognósticos investigados (estadiamento clínico, presença de ulceração, vascularização e tempo de evolução do processo). Os níveis séricos de estradiol aumentaram significativamente com o estadiamento clínico da doença (p<0,05). Verificou-se moderada correlação negativa entre os níveis séricos de estradiol e prolactina. Dessa forma, conclui-se que as dosagens séricas de estradiol e PRL foram influenciadas pela malignidade do tumor e pelo estadiamento clínico das neoplasias. Os receptores hormonais foram expressos pelas neoplasias, independentemente do tipo tumoral e não estão associados aos outros fatores prognóstico clássicos, como presença de ulceração, vascularização ou estadiamento clínico.(AU)

The aim of this study was to evaluate the serum concentrations of estradiol, progesterone, prolactin, the gene expression of estrogen α and β and progesterone receptors in bitches with mammary neoplasms. Sixty adult crossbred bitches distributed in two groups were used. Group I consisted of 30 bitches with mammary neoplasms and Group II consisted of 30 healthy bitches without neoplasia. For the tutors, interviews were made about the disease epidemiology. After preoperative examinations, bitches with mammary neoplasia were submitted to mastectomy; fragments of the neoplasms and regional lymph nodes were collected and processed for histopathological analysis. Blood samples were collected in tubes without anticoagulant and the serum was analyzed by electrochemiluminescence to measure estradiol, progesterone and prolactin. The gene expression of the hormonal receptors was performed by means of the Real-time PCR technique, thus fragments of mammary neoplasms were collected and the RNA was extracted to obtain cDNA. Expression of the mRNA for ERα, ERβ and PR was assessed from the amplification of these genes using specific primers. Higher serum levels of estradiol (mean 38.98±13.68pg/mL) were observed in bitches with malignant neoplasms when compared to the control bitches (p<0.05). Serum prolactin levels were higher (mean of 0.231±0.201ng/mL) in bitches that did not have mammary neoplasms when compared to Group I (p<0.05). No difference was observed for related to the progesterone levels between the groups (p>0.05). Both malignant and benign tumors expressed ERα, ERβ and RP with no statistical difference (p>0.05) and there were no difference related to the other prognostic factors investigated (clinical staging, presence of ulceration, vascularization and aging of neoplasms). Serum estradiol levels increased significantly with the clinical staging of the disease (p<0.05). There was a moderate negative correlation between serum levels of estradiol and prolactin. It was concluded that serum levels of estradiol and PRL were influenced by tumor malignancy and clinical staging of neoplasms. Hormonal receptors were expressed by neoplasms, regardless of tumor type and are not associated with other classical prognostic factors, such as ulceration, vascularization or clinical staging.(AU)

Knockdown of PAICS inhibits malignant proliferation of human breast cancer cell lines

BACKGROUND: Phosphoribosylaminoimidazole carboxylase, phosphoribosylaminoimidazole succinocarboxamide synthetase (PAICS), an enzyme required for de novo purine biosynthesis, is associated with and involved in tumorigenesis. This study aimed to evaluate the role of PAICS in human breast cancer, which remains the most frequently diagnosed cancer and the leading cause of cancer-related death among women in less developed countries. RESULTS: Lentivirus-based short hairpin RNA targeting PAICS specifically depleted its endogenous expression in ZR-75-30 and MDA-MB-231 breast cancer cells. Depletion of PAICS led to a significant decrease in cell viability and proliferation. To ascertain the mechanisms through which PAICS modulates cell proliferation, flow cytometry was performed, and it was confirmed that G1-S transition was blocked in ZR-75-30 cells through PAICS knockdown. This might have occurred partly through the suppression of Cyclin E and the upregulation of Cyclin D1, P21, and CDK4. Moreover, PAICS knockdown obviously promoted cell apoptosis in ZR-75-30 cells through the activation of PARP and caspase 3 and downregulation of Bcl-2 and Bcl-xl expression in ZR-75-30 cells. CONCLUSIONS: These findings demonstrate that PAICS plays an essential role in breast cancer proliferation in vitro, which provides a new opportunity for discovering and identifying novel effective treatment strategies.

Zinc and metalloproteinases 2 and 9: What is their relation with breast cancer? / Zinco e metaloproteinases 2 e 9: qual é a relação com câncer de mama?

Summary Zinc is the catalytic component of proteins that regulate responses to DNA damage, intracellular signaling enzymes, and matrix metalloproteinases, which are important proteins in carcinogenesis. The objective of this review is to bring current information on the participation of zinc and matrix metalloproteinases types 2 and 9 in mechanisms involved in the pathogenesis of breast cancer. We conducted a literature review, in consultation with the PubMed, Lilacs, and Scielo databases. The zinc and cysteine residues are structural elements shared by all members of the family of matrix metalloproteinases, and these proteins appear to be involved in the propagation of various types of neoplasms, including breast cancer. Moreover, transported zinc is likely to be used for the metalation of the catalytic domain of the newly synthesized metalloproteinases before the latter are secreted. Accordingly, increase in zinc concentrations in cellular compartments and the reduction of this trace element in the blood of patients with breast cancer appear to alter the activity of metalloproteinases 2 and 9, contributing to the occurrence of malignancy. Thus, it is necessary to carry out further studies with a view to clarify the role of zinc and metalloproteinases 2 and 9 in the pathogenesis of breast cancer.

Resumo O zinco é componente catalítico de proteínas que regulam respostas a danos no DNA, enzimas de sinalização intracelular e metaloproteinases de matriz, proteínas importantes na carcinogênese. O objetivo desta revisão é trazer informações atualizadas sobre a participação do zinco e das metaloproteinases de matriz dos tipos 2 e 9 em mecanismos envolvidos na patogênese do câncer de mama. Realizou-se um levantamento bibliográfico, mediante consulta às bases de dados PubMed, Scielo e Lilacs. O zinco e os resíduos de cisteína são elementos estruturais compartilhados por todos os membros da família das metaloproteinases de matriz, as quais parecem estar envolvidas na propagação de vários tipos de neoplasias, incluindo o câncer de mama. Além disso, é provável que o zinco transportado seja utilizado para metalação do domínio catalítico das metaloproteinases recentemente sintetizadas antes de serem segregadas. Nesse sentido, o aumento das concentrações de zinco em compartimentos celulares e a redução desse oligoelemento no sangue de pacientes com câncer de mama parecem alterar a atividade das metaloproteinases 2 e 9, contribuindo para a ocorrência de tumor maligno. Assim, faz-se necessária a realização de novos estudos na perspectiva de esclarecer o papel do zinco e das metaloproteinases 2 e 9 na patogênese do câncer de mama.

El organofosforado clorpirifos como disruptor estrogénico y factor de riesgo para el cáncer de mama / The organophosphorus chlorpyrifos as endocrine disruptor and breast cancer factor risk

El clorpirifos (CPF) es un insecticida de amplio espectro que se utiliza en Argentina y en otros países de Latinoamérica. Se emplea para el control de plagas en la producción de frutas, hortalizas, cereales y plantas ornamentales. El principal mecanismo de acción descripto para este insecticida es la inhibición de la acetilcolinesterasa. Sin embargo, reportes más recientes sugieren múltiples efectos del plaguicida independientes de la inhibición de esa enzima. El objetivo de este trabajo es transmitir a la comunidad los resultados de nuestras investigaciones obtenidos utilizando diferentes dosis de CPF en distintos modelos experimentales, tanto in vitro como in vivo. En relación a esto, hemos evidenciado una acción del CPF sobre el sistema redox celular que conduce al incremento de especies reactivas del oxígeno y consecuentemente a la activación de diferentes vías de señalización. Además, hemos determinado que el insecticida CPF puede comportarse como un disruptor endócrino modulando la acción de los estrógenos y alterando la normal estructura del tejido mamario. Nuestros resultados alertan sobre el impacto que este compuesto podría tener sobre la salud, sugiriendo la necesidad de revisar su uso dado que manifiesta acciones a dosis encontradas en el ambiente.

Chlorpyrifos (CPF) is a broad spectrum insecticide used in Argentina and other Latin American countries. It is commonly used for pest control in the production of fruits, vegetables, cereals and ornamental plants. The main mechanism of action described for this insecticide is the inhibition of acetylcholinesterase activity. However, more recent reports suggest multiple effects for this pesticide in an independent way from the inhibition of this enzyme. The objective of this work is to convey to the community the results of our investigations obtained using different doses of CPF in various experimental models, both in vitro and in vivo. In this connection, we have shown a CPF action on the cellular redox system which leads to increased reactive oxygen species and the consequent activation of different signaling pathways. In addition, we have determined that the insecticide CPF acts as an endocrine disruptor modulating the action of estrogen and altering the normal structure of breast tissue. Our findings warn about the impact that this compound might have on health, suggesting the need to review its use since adverse actions were found at environmentally relevant doses.

Association of junk food consumption with high blood pressure and obesity in Iranian children and adolescents: the CASPIAN-IV Study / Associação entre o consumo de junk food e a pressão arterial alta e obesidade em crianças e adolescentes iranianos: o Estudo Caspian-IV

OBJECTIVE: This study aimed to evaluate the association of junk food consumption with hypertension and obesity in a national sample of Iranian children and adolescents. METHODS: This nationwide study was conducted in 2011-2012 among 14,880 students, aged 6-18 years, selected by cluster sampling from 30 provinces. Weight, height, waist circumference (WC), hip circumference (HC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), as well as systolic and diastolic blood pressure (BP) were measured. Junk food was divided into four categories, including salty snacks, sweets, sweetened beverages, and fast food. Subjects reported how many times they had consumed each item (daily, weekly, and seldom). RESULTS: The intake of sweets was significantly associated with anthropometric indices and BP levels. Moreover, a significant association was found between fast food consumption, BP levels, and anthropometric indices (except for WHtR and WHR). Sweet beverages consumption was significantly associated with anthropometric indices; however, the consumption of salty snacks was only significantly associated with height, HC, and WHR. The risk of general obesity (OR: 0.75, 95% CI: 0.65-0.87) and abdominal obesity (OR: 0.81, 95% CI: 0.72-0.92) among participants who seldom consumed sweets was less than those who consumed daily. Also, the risk of general obesity (OR: 0.85, 95% CI: 0.74-0.97) among students that seldom consumed sweetened beverages was less than subjects who consumed them on a daily basis. CONCLUSION: It was found that junk food consumption increased the risk of both general and abdominal obesity; therefore, consumption of junk food should be reduced via restricting TV advertisements and increasing taxes on junk foods. .

OBJETIVO: Avaliar a associação entre o consumo de junk food e a hipertensão e obesidade em uma amostra nacional de crianças e adolescentes iranianos. MÉTODOS: Este estudo nacional foi feito entre 2011 e 2012 com 14.880 estudantes com seis-18 anos, selecionados por amostra em bloco em 30 províncias. Foram medidos o peso, a estatura, a circunferência da cintura (CC), a circunferência do quadril (CQ), a razão cintura/quadril (RCQ), a razão cintura/estatura (RCE) e a pressão arterial sistólica e diastólica (PAS e PAD). A junk food foi dividida em quatro categorias, incluindo lanches salgados, doces, bebidas açucaradas e fast food. Os indivíduos relataram quantas vezes consumiam cada um dos itens (diariamente, semanalmente, raramente). RESULTADOS: O consumo de doces foi associado significativamente aos índices antropométricos e níveis de pressão arterial (PA). Além disso, havia uma associação significativa entre o consumo de fast food e os níveis de PA e os índices antropométricos (exceto RCE e RCQ). O consumo de bebidas açucaradas foi associado significativamente aos índices antropométricos, porém o consumo de lanches salgados foi associado significativamente apenas a estatura, CQ e RCQ. O risco de obesidade geral (RC: 0,75, IC de 95%: 0,65-0,87) e obesidade abdominal (RC: 0,81, IC de 95%: 0,72-0,92) entre participantes que raramente consumiam doces era menor do que naqueles que os consumiam diariamente. Além disso, o risco de obesidade geral (RC: 0,85; IC de 95%: 0,74-0,97) entre estudantes que raramente consumiam bebidas açucaradas era menor do que entre indivíduos que os consumiam diariamente. CONCLUSÃO: Constatamos que o consumo de junk food aumentou o risco de obesidade geral e abdominal; portanto, o consumo de junk food deve ser reduzido por meio da restrição de comerciais de TV e do aumento de impostos sobre esse tipo de alimento. .

Evaluation of HER-2/neu status in breast cancer specimens using immunohistochemistry (IHC) & fluorescence in-situ hybridization (FISH) assay.

Background & objectives: Fluorescence in situ hybridization (FISH) is increasingly being recognized as the most accurate and predictive test for HER2/neu gene amplification and response to therapy in breast cancer. In the present study we investigated HER-2/neu gene amplification by FISH in breast carcinoma tissue specimens and compared the results with that of immunohistochemical (IHC) analysis. Methods: A total of 90 breast carcinoma tissue samples were used for immunohistochemical (IHC) and FISH analysis. IHC was performed by using mouse monoclonal antibody to the intracellular domain of HER-2/neu protein. Each slide was scored in a blinded fashion by two pathologists according to the manufacturer's recommended criteria. FISH analysis was performed on paraffin embedded breast tumour tissue sections. The polysomy for centromere 17 (Spec green signal) was read as green signals less than 4 as moderate polysomy, and more than 4 as highly polysomy. Results: Thirty of the 90 patients had negative results by IHC and FISH. Of the 28 patients with the score of 2+ by IHC, 20 were FISH positive for HER-2/neu gene amplification, three were FISH negative and five patients showed equivocal (1.8-2.2) results by FISH. These five cases were retested for IHC and FISH on different paraffin embedded tissue blocks, and all five were found positive for HER-2/neu gene amplification. Twenty five patients with the score of 3+ by IHC were FISH positive for HER-2/neu gene amplification (>2.2). Seven cases with the score of 3+ by IHC were FISH negative for HER-2/neu gene amplification (>2.2), and showed polysomy of chromosome number 17 high polysomy > 4. Interpretation & conclusions: Our results indicated that HER-2/neu status by FISH should be performed in all cases of breast tumour with a 2+ score by IHC. Cases demonstrating a 3+ score by IHC may be subjected to FISH to rule out polysomy of chromosome 17 which could be falsely interpreted as HER-2/neu overexpression by IHC analysis. There is also a need for establishing a clinically validated cut-off value for HER-2/neu FISH amplification against IHC which may be further compared and calibrated.

A functional comparison between the HER2high/HER3 and the HER2low/HER3 dimers on heregulin-beta1-induced MMP-1 and MMP-9 expression in breast cancer cells

Overexpression of HER2 correlates with more aggressive tumors and increased resistance to cancer chemotherapy. However, a functional comparison between the HER2high/HER3 and the HER2low/HER3 dimers on tumor metastasis has not been conducted. Herein we examined the regulation mechanism of heregulin-beta1 (HRG)-induced MMP-1 and -9 expression in breast cancer cell lines. Our results showed that the basal levels of MMP-1 and -9 mRNA and protein expression were increased by HRG treatment. In addition, HRG-induced MMP-1 and -9 expression was significantly decreased by MEK1/2 inhibitor, U0126 but not by phosphatidylinositol 3-kinase (PI-3K) inhibitor, LY294002. To confirm the role of MEK/ERK pathway on HRG-induced MMP-1 and -9 expression, MCF7 cells were transfected with constitutively active adenoviral-MEK (CA-MEK). The level of MMP-1 and -9 expressions was increased by CA-MEK. MMP-1 and -9 mRNA and protein expressions in response to HRG were higher in HER2 overexpressed cells than in vector alone. The phosphorylation of HER2, HER3, ERK, Akt, and JNK were also significantly increased in HER2 overexpressed MCF7 cells compared with vector alone. HRG-induced MMP-1 and -9 expressions were significantly decreased by lapatinib, which inhibits HER1 and HER2 activity, in both vector alone and HER2 overexpressed MCF7 cells. Finally, HRG-induced MMP-1 and MMP-9 expression was decreased by HER3 siRNA overexpression. Taken together, we suggested that HRG-induced MMP-1 and MMP-9 expression is mediated through HER3 dependent pathway and highly expressed HER2 may be associated with more aggressive metastasis than the low expressed HER2 in breast cancer cells.

Cyclooxygenase-2 and human epidermal growth factor receptor type 2 (HER-2) expression simultaneously in invasive and in situ breast ductal carcinoma / Expressão da ciclo-oxigenase-2 e receptor tipo 2 do fator de crescimento epidérmico humano (HER-2) simultaneamente em carcinoma ductal de mama in situ e invasivo

CONTEXT AND OBJECTIVE: Cyclooxygenase-2 (COX-2) and human epidermal growth factor receptor type 2 (HER-2) are associated with tumorigenesis. Studies have shown that HER-2 can regulate COX-2 expression. The aim of this study was to evaluate the correlation between COX-2 and HER-2 expression in normal breast epithelium and in ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC) present in the same breast. DESIGN AND SETTING: Cross-sectional study at the Mastology Unit of the Department of Gynecology and Obstetrics, Santa Casa de Misericórdia de São Paulo Hospital. METHODS: COX-2 and HER-2 were detected using immunohistochemistry on 100 tissue fragments. HER-2 > +2 was subjected to fluorescence in situ hybridization (FISH). RESULTS: COX-2 expression was detected in 87 percent, 85 percent and 75 percent of IDC, DCIS and normal epithelium, respectively. HER-2 expression was detected in 34 percent of IDC and 34 percent of DCIS. COX-2 in DCIS correlated with HER-2 in IDC (P = 0.049) and DCIS (P = 0.049). COX-2 in normal epithelium correlated with HER-2 in IDC (P = 0.046) and DCIS (P = 0.046). COX-2 in IDC was not associated with HER-2 (P = 0.235). Comparison between COX-2 and HER-2 in DCIS showed that there was a statistically significant difference with regard to nuclear grades II and III and presence of comedonecrosis (P < 0.001). In IDC, there was significant expression with nuclear grades II and III and histological grade II (P < 0.001). CONCLUSIONS: Our findings provide evidence that HER-2 and COX-2 regulate each other.

CONTEXTO E OBJETIVO: Ciclo-oxigenase (COX-2) e receptor tipo 2 do fator de crescimento epidérmico humano (HER-2) estão associados com tumorigênese. Estudos mostraram que HER-2 pode regular a expressão de COX-2. O objetivo deste estudo foi avaliar a correlação entre expressão da COX-2 e HER-2 no epitélio normal de mama, no carcinoma ductal in situ (DCIS) e carcinoma ductal invasivo (IDC) presentes na mesma mama. TIPO DE ESTUDO E LOCAL: Estudo transversal na clínica de Mastologia do Departamento de Obstetrícia e Ginecologia do Hospital da Santa Casa de Misericórdia de São Paulo. MÉTODOS: A detecção da COX-2 e HER-2 foi realizada por imunoistoquímica em 100 fragmentos teciduais. HER-2 > +2 foi submetido a hibridização fluorescente in situ (FISH). RESULTADOS: Expressão de COX-2 foi detectada em 87 por cento, 85 por cento e 75 por cento dos IDC, DCIS e epitélio normal, respectivamente. Expressão de HER-2 foi detectada em 34 por cento dos IDC e 34 por cento de DCIS. COX-2 em DCIS correlacionou-se com HER-2 em IDC (P = 0,049) e DCIS (P = 0,049). COX-2 no epitélio normal correlacionou-se com HER-2 em IDC (P = 0,046) e DCIS (P = 0,046). COX-2 no IDC não foi associada com HER-2 (P = 0,235). Quando comparado COX-2 com HER-2 em DCIS houve diferença estatisticamente significante com relação ao grau nuclear II e III e presença de comedonecrose (P < 0,001) e no IDC, houve expressão significativa no grau nuclear II e III e histológico II (P < 0,001). CONCLUSÕES: Nossos achados mostram evidências que HER-2 e COX-2 se autorregulam.

Modulatory effect of plasma folate and polymorphisms in one-carbon metabolism on catecholamine methyltransferase (COMT) H108L associated oxidative DNA damage and breast cancer risk.

The present study was aimed to investigate the modulatory role of plasma folate and eight putatively functional polymorphisms of one-carbon metabolism on catecholamine methyltransferase (COMT)-mediated oxidative DNA damage and breast cancer risk. Plasma folate and 8-oxo-2’-deoxyguanosine (8-oxodG) were estimated by commercially available kits, while polymorphisms were screened by PCR-RFLP and PCR-AFLP methods. COMT H108L polymorphism showed independent association with breast cancer (OR: 1.73, 95% CI: 1.31-2.30). No significant interaction was observed between folate status and COMT genotype. Multifactor dimensionality reduction (MDR) analysis gave evidence for the significant epistatic (gene-gene) interactions (p<0.0001) of COMT H108L with reduced folate carrier 1 (RFC1) G80A, thymidylate synthase (TYMS) 5’-UTR 3R2R, TYMS 3’-UTR ins6/del6. Increased plasma 8-oxodG were observed in cases compared to controls (mean ± SE: 5.59 ± 0.60 vs. 3.50 ± 0.40 ng/ml, p<0.004). Plasma folate deficiency alone was not a significant predictor of 8-oxodG elevation. The genotype combinations namely, RFC1 G80A/methionine synthase reductase (MTRR) A66G, RFC1 G80A/SHMT C1420T/TYMS 3R2R and serine hydroxymethyltransferase (SHMT) C1420T/TYMS 3R2R/methionine synthase (MTR) A2756G/COMT H108L were strong predictors of 8-oxodG elevation in the order of risk. To conclude, the current study provides substantial evidence for a cross talk between one-carbon metabolism and COMT catalysis that might influence oxidative DNA damage and breast cancer risk.

Prevalence of the STK15 F31I polymorphism and its relationship with mammographic density

Several studies have identified the single nucleotide polymorphism STK15 F31I as a low-penetrance risk allele for breast cancer, but its prevalence and risk association in the Brazilian population have not been determined. The goal of this study was to identify the frequency of this polymorphism in the Brazilian setting. Considering the high degree of admixture of our population, it is of fundamental importance to validate the results already reported in the literature and also to verify the relationship between this variant and breast cancer risk. A total of 750 women without breast cancer were genotyped using the TaqMan PCR assay for STK15 F31I polymorphism. Clinical information was obtained from review of the medical records and mammographic density from the images obtained using the BI-RADS System. The estimated risk of developing cancer was calculated according to the Gail model. The genotypic frequencies observed in this study were 4.5, 38.7, and 56.6 percent, respectively, for the STK15 F31I AA, AT and TT genotypes. The AT and AA genotypes were encountered significantly more often in premenopausal women with moderately dense, dense and heterogeneously dense breast tissue (P = 0.023). In addition, the presence of the TT genotype was significantly associated with age at menarche ≥12 years (P = 0.023). High mammographic density, associated with increased breast cancer risk, was encountered more frequently in premenopausal women with the risk genotypes STK15 F31I AA and AT. The genotypic frequencies observed in our Brazilian sample were similar to those described in other predominantly European populations.

Inhibitory effect of zinc, copper and selenium on telomerase activity in tumor tissues and t47d breast cancer cell line

The present study was performed to investigate the effects of trace elements particularity Se, Zn and Cu on tumor genesis in breast cancer. The inhibitory effect of Se, Zn and Cu, on telomerase activity was analyzed in human breast tumor tissues and breast cancer [T47D] cells. Tissue specimens from 24 women with benign breast disease and 32 women with breast cancer specimens [ductal carcinoma, lobular carcinoma] were collected during surgery. In addition venous blood samples were obtained for assessing the trace elements. T47D cell line was cultured and treated with trace elements. Telomerase activity then was measured with TRAP assay in cell line and tissue extracts. There was a significant difference between tissue and serum levels of Cu, Se and the ratio of Cu/Zn in patients and controls [P<0.001]. After treating with 100 microm/L Zn So4, 10 um /L Cu So4 for 6 hours, telomerase activity of T47D cells was markedly increased. But after treating with 10, and 30 um /L selenium-L- methionin, telomerase activity was markedly inhibited. Telomerase activity of T47D cells for 24 hours were 0.93, 0.60 and for 48 hours were 0.76, 0.12 respectively [control 49.2%]. There were variations in serum level of Zn and Cu in breast cancer patients. Association between trace elements level and telomerase activity level can be exploited as prognostic and diagnostic marker for breast cancer

Avaliação epidemiológica da influência dos genes GSTM1 e GSTT1 na susceptibilidade ao câncer de mama em mulheres atendidas em um hospital do Sul do Brasil: um estudo-piloto / Epidemiological evaluation of the influence of GSTM1 and GSTT1 genes in susceptibility to breast cancer in women cared for at a hospital in South Brazil: a pilot study

Introdução: A glutationa S-transferase (GST) é uma família de enzimas intracelulares que catalisam a conjugação de compostos eletrolíticos diversos, promovendo a formação de substâncias menos reativas e mais solúveis em água. Os genes GSTM1 e GSTT1 são polimórficos em humanos, e estão presentes ou ausentes de forma homozigótica em diferentes populações étnicas. Indivíduos com a deleção homozigótica destes genes podem ser mais susceptíveis ao desenvolvimento de doenças atribuídas à exposição de carcinógenos. O objetivo deste estudo foi verificar se a ocorrência de deleções homozigóticas dos genes GSTM1 e GSTT1 estão associadas com o aumento da susceptibilidade ao câncer de mama. Métodos: Estudo de caso-controle incluindo 15 mulheres portadoras de câncer e 30 mulheres sem câncer. A deleção homozigótica dos genes GSTM1 e GSTT1 foi identificada através da reação em cadeia da polimerase. Os dados obtidos foram analisados no software SPSS 12.0. Resultados: Entre os dados epidemiológicos analisados nenhum foi associado com o risco para o desenvolvimento de câncer de mama. Foi observado um percentual de 44,4% e 46,7% de deleção homozigótica para os genes GSTM1 e GSTT1, respectivamente. A dupla deleção homozigótica foi observada em uma frequência significativamente maior entre os casos [RR = 7,9 (95%, IC: 1,637,7~ p<00,1)]. Conclusão: A dupla deleção homozigótica está associada com a susceptibilidade ao câncer de mama na população estudada, entretanto novos estudos devem ser realizados para confirmar esses achados. A detecção precoce da ausência desses genes poderia permitir uma melhor abordagem diagnóstica e um planejamento mais adequado do tratamento de mulheres com câncer de mama

Introduction: Glutathione S transferase (GST) is a family of intracellular enzymes that catalyze the conjugation of various electrolytic compounds, promoting the formation of substances which are less reactive and more soluble in water. Genes GSTM1 and GSTT1 are polymorphic in humans and are present or absent in homozygous form in different ethnic populations. Individuals with homozygous deletion of these genes may be more susceptible to development of diseases attributed to exposure to carcinogens. The aim of this study was to determine whether the occurrence of homozygous deletions of GSTM1 and GSTT1 are associated with increased susceptibility to breast cancer. Methods: A case-control study including 15 women with cancer and 30 women without cancer. Homozygous deletion of GSTM1 and GSTT1 genes was identified by polymerase chain reaction. Data were analyzed with SPSS 12.0. Results: Among the epidemiological data analyzed none was associated with risk for developing breast cancer. We found percentages of 44.4% and 46.7% for homozygous deletion of GSTM1 and GSTT1, respectively. Double homozygous deletion was detected in a significantly higher frequency among the cases [OR = 7.9 (95% CI: 1,637,7, p <0.1)]. Conclusion: Double homozygous deletion is associated with susceptibility to breast cancer in this population. However, further studies should be conducted to confirm these findings. Early detection of the absence of these genes could provide better diagnosis and more appropriate planning of care for women with breast cancer

Cox-2 e sua associação com fatores prognósticos e resposta à quimioterapia primária em pacientes com câncer de mama / Cox-2 and its association with prognostic factors and response to primary chemotherapy in patients with breast cancer

OBJETIVO: Avaliar em pacientes com câncer de mama a expressão imunoistoquímica da cox-2 antes da quimioterapia primária com 5-fluorouracil, epirrubicina e ciclofosfamida (FEC) e a associação desta com tamanho inicial do tumor, estado linfonodal, receptores hormonais, expressão da Her-2 e com a resposta clínica e anatomopatológica. MÉTODOS: Estudo retrospectivo com 41 mulheres portadoras do diagnóstico histopatológico de carcinoma ductal de mama. Foram submetidas à quimioterapia primária com esquema FEC (5-fluorouracil, epirrubicina e ciclofosfamida) na dosagem de 500mg/m2, 75mg/m2 e 500 mg/m2, respectivamente. Os critérios de inclusão foram intervalo etário entre 30 e 70 anos, estadiamento II a IIIA, após comprovação da ausência de metástase, tumor primário de mama, único e unilateral, tipo histológico ductal invasivo e ausência de cardiopatia e gestação. Para avaliação da expressão da proteína Her 2 neuutilizaram-se anticorpos monoclonais de coelho. Para visibilizar a expressão da proteína cox-2 utilizaram-se anticorpos policlonais obtidos do soro de cabras. A avaliação da resposta clínica ao tratamento foi realizada por exame físico mensurando-se o maior eixo tumoral por paquímetro. As medidas foram realizadas à admissão e após os ciclos de quimioterapia primária. Após três sessões quimioterápicas com intervalos de 21 dias realizou-se o procedimento cirúrgico. Adotaram-se os critérios do RECIST. Após a operação foi avaliada a resposta anatomopatológica local, sendo considerada completa quando da ausência de neoplasia invasiva e do componente in situ. Na avaliação imumoistoquímica para os receptores de estrogênio utilizaram-se estrogen receptor NCL-ER6F11 e para progesterona, progesterone receptor, NCL-PGR-312 considerando positiva quando da coloração em 10 por cento ou mais das células tumorais. RESULTADOS: A distribuição segundo estadiamento clínico UICC verificaram-se seis no estádio IIA (14,6 por cento), 22 no estádio IIB (53,6 por cento) e 13 estádio IIIA (31,8 por cento). A avaliação clínica inicial do maior eixo tumoral variou de 2,5 a 15 cm e mediana de 5 cm. Foram identificadas 14 pacientes (34,1 por cento) com estado linfonodal negativo e 27 positivo (65,9 por cento). Observou-se que 19 (46,3 por cento) apresentavam-se no menacme e 22 (53,6 por cento) na menopausa. CONCLUSÃO: Houve associação da expressão da cox-2 à fatores de pior prognóstico no câncer de mama como estado linfonodal positivo, receptores hormonais negativos e expressão da Her-2.

OBJECTIVE: To evaluate the immunohistochemical expression of cox-2 before primary chemotherapy with 5-fluorouracil, epirubicin and cyclophosphamide (FEC) and its association with initial tumor size, lymph node status, hormone receptors, expression of HER2 and the clinical and pathological response in patients with breast cancer. METHODS: We conducted a retrospective study with 41 women with histopathological diagnosis of ductal breast carcinoma. They underwent primary chemotherapy with FEC regimen (5-fluorouracil, epirubicin and cyclophosphamide) at 500mg/m2, 75mg/m2 and 500 mg/m2, respectively. Inclusion criteria were age range between 30 and 70 years, stage II to IIIA, absence of metastasis, primary tumor of the breast, single, unilateral, with ductal invasion at histology and absence of heart disease and pregnancy. To evaluate the expression of HER2/neu protein we used rabbit monoclonal antibodies. To visualize the expression of cox-2 protein we used polyclonal antibodies obtained from goats' serum. The evaluation of clinical response to treatment was performed during physical examination by measuring the major tumor axis with a pachymeter. Measurements were taken at admission and after primary chemotherapy cycles. After three chemotherapy sessions at intervals of 21 days the surgical procedure was carried out. We adopted the criteria of RECIST. After the operation we evaluated the local pathological response, which was considered complete when there was absence of invasive neoplasia and of the in situ component. In immunohistochemical assessing of estrogen receptors we used estrogen receptor NCL-ER6F11 and, for progesterone, progesterone receptor NCL-PGR-312, considering positive the staining of 10 percent or more tumor cells. RESULTS: The distribution according to UICC clinical stage classified six patients in stage IIA (14.6 percent), 22 in stage IIB (53.6 percent) and 13 stage IIIA (31.8 percent). The initial clinical evaluation of the major tumor axis ranged from 2.5 to 15 cm and a median of 5 cm. We identified 14 patients (34.1 percent) with negative lymph node status, and 27 positive (65.9 percent). It was observed that 19 (46.3 percent) were in premenopause and 22 (53.6 percent) in menopause. CONCLUSION: There was an association of the expression of Cox-2 to the factors associated with poor prognosis in breast cancer, such as positive lymph node status, negative hormone receptors and HER2 expression.

Clinical significance of matrix metalloproteinase 2 and 9 in breast cancer.

Background: Invasion and metastasis are the most strenuous problems in the management of breast cancer. These events require diverse proteolytic enzymes, among which MMP-2 and MMP-9 play a significant role in degradation of type IV collagen, the major component of the basement membrane. Therefore, the major objective of the study is to evaluate the clinical usefulness of MMP-2 and MMP-9 with respect to malignant tumor growth, invasion, and metastasis in breast cancer. Materials and Methods: Gelatin zymography was performed on 157 tissue extracts of malignant and adjacent normal breast tissues as well as negative and positive lymph nodes from 49 breast cancer patients. Statistical analysis was carried out using SPSS statistical software (version 10). Results: ProMMP-2 levels were significantly higher in adjacent normal tissues. Active MMP-2 and MMP-9 levels were higher in malignant breast tissues. Activation ratios of MMP-2 and MMP-9 were significantly higher in malignant breast tissues and in patients with lymph node metastasis. ProMMP-2, active MMP-2, and active MMP-9 could significantly discriminate between malignant and adjacent normal breast tissues. The MMP-2 activation ratio showed significant discriminatory efficacy between patients with and without lymph node metastasis and significant association with increased risk of lymph node metastasis in node-negative patients. Conclusion: The results indicate significant clinical utility of these proteolytic enzymes in malignant tumor growth, invasion, and metastasis in breast cancer.

Correlação entre COX-2 e ciclina D-1 após administração de tamoxifeno neoadjuvante em curto prazo no tratamento de carcinoma de mama / Correlation of COX-2 and ciclyn D-1 after short-time neoadjuvant tamoxifen on breast cancer

Introdução: O tamoxifeno é a droga utilizada há mais tempo na terapia hormonal do câncer de mama. A superexpressão da ciclina D-1 interfere negativamente no tratamento com tamoxifeno e pode contribuir para predição da falha terapêutica observada em algumas pacientes. COX-2 induz a oxidação de estrogênio a dietilestilbestrol e importante ação genotóxica na mama. Ciclina D-1 e COX-2 ainda não foram descritos associados em relação ao tratamento com tamoxifeno em curto período (14 dias). Objetivo: Avaliar os efeitos da administração neoadjuvante de tamoxifeno em curto prazo (14 dias) sobre a expressão de COX-2 e ciclina D -1 no tratamento do câncer de mama. Métodos: Estudo prospectivo randomizado realizado na disciplina de Mastologia da Unifesp. Vinte e cinco pacientes com carcinoma de mama nos estádios II e III, subdivididas em grupos (controle, n=13, e tratamento, n=12). As amostras de ciclina D-1 e COX-2 foram avaliadas antes e após o tratamento. A avaliação imuno-histoquímica foi realizada por meio de anticorpos policlonais para COX-2 (Novo castra - Clone 4H12) e ciclina D-1 (Novocastra - Clone DCS-6). Os resultados foram classificados de acordo com a fração e intensidade de coloração das células marcadas. Resultados: Observou-se positividade da COX-2 em 56% dos tumores, sem diferença significativa nos dois momentos da amostra (p = 0,39 - Mann Whitney test*1). A expressão da COX-2 não apresentou diferença significativa nas amostras pré e pós nos grupos controle e tratamento. Na amostra total do estudo, observou-se alteração da expressão da ciclina D-1 entre os dois momentos da amostra (teste de McNemar - Diferença = 36.00% (p = 0,06). Entre os grupos controle e tratamento, observou-se que a diferença das medianas de ciclina D-1 entre as amostras pós e pré (pós - pré) demonstrou tendência à significância estatística pelo teste de Mann-Whitney (p = 0,08). Conclusão: O tratamento neoadjuvante com tamoxifeno em curto prazo (14 dias) não foi capaz de modificar...

Introduction: Tamoxifen is the most used drug in the hormonal therapy of the breast cancer. Ciclyn D-J, one CCNDJ gene product's (PRADJ), is essential for the normal lobule-alveolar mammary development and acts in the cellular cycle control. Ciclyn D-I superexpression act negatively in tamoxifen treatment, and may contribute to predict the failure observed in some patients. COX-2 activity induces oestrogen oxidation to dietilstilbestrol and promotes genotoxics effects on the breast. Ciclyn D-1 and COX-2 association had not been described yet to short time tamoxifen treatment. Objective: Evaluate short time (14 days) neoadjuvant tamoxifen effects on COX-2 and ciclyn D-1 expression in breast cancer patients. Methods: Randomized prospective study in the Federal University of Sao Paulo. Twenty five patients with stage II and III breast cancer were included. The groups were control (n = 13) and treatment (n = 12). Ciclyn D-1 and COX-2 samples were evaluated before and after treatment. Imunohistochemistry was performed on the tissue sections using a polyclonal antibody to COX-2 (Novocastra - Clone 4H12) and cyclin D-1 (Novocastra - Clone DCS-6). The results were classified according Already score, based on the intensity and fraction marked cells. Results: COX-2 was positive in 56% of tumors. No significant difference was observed between the two groups (p = 0.39 Mann Whitney test). The Difference of cyclin D-1 medium (post - pre) in the control group was 5, while in the tamoxifen group was 0.5. (p=0.08, Mann Whitney test). Correlation between COX-2 and ciclyn D-1 was expressed by Pearson index (r). In treatment group moderate linear and positive correlation was observed (r = 0.51 - Pearson's index) (p = 0.08). It wasn't observed in control group (r = 0.42) (p = 0.12). Conclusion: Tamoxifen treatment in short time period (14 days) wasn't modified significantly COX-2 and ciclyn D-1 expression.

Implications of free radicals and antioxidant levels in carcinoma of the breast: a never-ending battle for survival.

BACKGROUND: Under normal circumstances, there is a steady balance between the production of oxygen derived free radicals and their destruction by the cellular antioxidant system inside the human body. However, any imbalance between the levels of these oxidants and antioxidants might cause DNA damage and may lead to cancer development. The aim of this study was to evaluate the level of antioxidants and free radicals in blood and tissue of cancer patients and compare these levels at different TNM stages to derive the possible role of free radicals and antioxidant enzymes in the etiology of breast cancer. MATERIALS AND METHODS: This study includes 30 patients suffering from cancer breast and 20 patients as controls who had benign breast diseases. Circulating lipid peroxide (Malonyldialdehyde [MDA]) levels and activities of the defensive enzymes (Superoxide Dismutase [SOD] and Catalase [CAT]) were estimated in the blood and breast tissue of these patients. RESULTS: Increased levels of free radicals and low levels of antioxidants were observed in malignant tissue. An elevated lipid peroxide concentration was found in the tissue of all the cancer breast patients as evidenced by an increase in the mean MDA level seen with increasing TNM stage of carcinoma breast. Levels of antioxidants SOD and CAT were decreased in cancer patients. CONCLUSION: The results of our study suggest that free radical activity is enhanced in cancer breast patients while the antioxidant defense mechanism is weakened. This activity is enhanced with the increasing severity of cancer as depicted in different TNM stages of breast cancer.

Survival effects of cyclooxygenase-2 and 12-lipooxygenase in Egyptian women with operable breast cancer.

BACKGROUND: Breast cancer (BC) is the commonest among women in Egypt as well as in many other countries. Cyclo-oxygenase-2 (COX-2) and 12-lipo-oxygenase (12-LOX) are over-expressed in 30-40% of patients and carry a poor prognosis. The objectives of this study were to correlate COX-2 and 12-LOX expression with various clinico-pathologic patients' characteristics and their impact on overall survival (OS) and disease free survival (DFS) in Egyptian women with operable BC. MATERIALS AND METHODS: This prospective study included 57 consecutive BC cases presenting to the Egyptian National Cancer Institute. Sections from BC and nearby normal tissues were examined for expression of COX-2 and 12-LOX using reverse transcriptase polymerase chain reaction. RESULTS: The patients' median age was 45 years. Fifty-three percent were premenopausal. Stage II and III disease represented 25 and 75% respectively. Adjuvant chemotherapy, radiotherapy and tamoxifen were used in 90, 75 and 60% respectively. Sixty percent had hormone-receptor positive tumors and 28% over-expressed HER2/neu. Forty-nine and sixty-five percent showed over-expression of COX-2 and 12-LOX respectively. Patients with higher TNM stage or who developed visceral metastases had significantly higher COX-2 expression. For the whole group of patients, the median DFS was 37 months, while the median OS was not reached. OS or DFS did not differ significantly between patients with normal and over-expression of COX-2. DFS but not OS was significantly higher in 12-LOX over-expression compared to normal expression. CONCLUSION: COX-2 over-expression was associated with poor prognostic criteria in BC, but did not affect DFS or OS. 12-LOX over-expression was associated with better DFS, but not OS.

Expressão da aromatase em carcinomas de mama ductais invasivo e in situ presentes na mesma mama / Aromatase expression in invasive and in situ ductal carcinoma present in the same breast

OBJETIVO: Avaliar expressão da enzima aromatase nos carcinomas de mama ductais invasivos (CDI), in situ (CDIS), no epitélio e estromas adjacentes. MÉTODOS: Foram avaliados 45 espécimes cirúrgicos provenientes de mastectomias e quadrantectomias com CDI e CDIS concomitantes de pacientes com estadios clínicos I e II. A análise da expressão da enzima aromatase foi realizada por meio de anticorpos policlonais antiaromatase e categorização das amostras de acordo com intensidade e número de células coradas. RESULTADOS: Nos 45 casos de CDI a expressão da aromatase foi positiva em 32 espécimes (71 por cento) e negativa em 13 (29 por cento). Nos casos de CDIS, a positividade foi idêntica à observada no CDI, mostrando correlação positiva. No epitélio normal constatou-se expressão positiva em 19 casos (42,2 por cento) e negativa nos outros 26 (57,8 por cento), mostrando correlação positiva estatisticamente (p<0,01), quando comparada com CDI e CDIS. Na análise do estroma normal a expressão da aromatase foi observada em apenas sete (15,5 por cento) dos 45 casos avaliados, não apresentando correlação com nenhuma variável analisada para expressão da aromatase. A presença da aromatase no estroma tumoral foi positiva em 36 casos (80 por cento) e negativa em 9 (20 por cento), mostrando correlação estatisticamente com a expressão no CDI (p<0,01) e no CDIS (p<0,01). Ao se comparar a expressão da aromatase no CDI, CDIS, epitélio normal e estroma tumoral com os graus nuclear e histológico, tamanho tumoral e idade da paciente, não foram encontradas diferenças estatisticamente significantes. CONCLUSÃO: Os resultados revelaram alta correlação entre expressão da aromatase no CDI, CDIS, epitélio normal e estroma tumoral, sugerindo possível mecanismo de ação autócrina e parácrina desta enzima na gênese do câncer de mama.

OBJECTIVE: to evaluate the expression of aromatase in simultaneously invasive ductal carcinoma (IDC) and ductal carcinoma in situ (DCIS). METHODS: forty-five surgical samples were obtained from mastectomy and quadrantectomy with simultaneous IDC and DCIS of stage I and II patients. Aromatase was evaluated using antibodies anti-aromatase and the samples classified in accordance with the number and intensity of stained cells. RESULTS: Aromatase was expressed positively in 32(71 percent) and negatively in 13(29 percent) of the cases in the IDC. The same results were obtained in the DCIS showing a perfect positive correlation. In the normal epithelium,aromatase was positive in 19(42.2 percent) and negative in 26 (57.8 percent) and a positive correlation, statistically significant was obtained when compared with IDC and DCIS(p<0.01). Concerning the normal stroma, positivity was only 7 (15.5 percent) showing no correlation with aromatase expression. Aromatase was positive in 36(80 percent) of the tumor stroma and this result was statistically significant as in the IDC and DCIS. Comparing results of aromatase expression with nuclear grade, histological grade, tumor size and age no difference was found. CONCLUSION: our results demonstrated high correlation between aromatase expression in IDC, DCIS, normal epithelium and tumor stroma showing a possible autocrine and paracrine mechanism of this enzyme in breast cancer.

Características mamográficas do câncer de mama associadas aos polimorfismos GSTM1 e GSTT1 / Polymorphisms GSTM1 and GSTT1 and sporadic breast cancer mammographic features

INTRODUÇÃO: As enzimas do sistema da glutationa S-transferase (GST) modulam os efeitos da exposição a vários agentes citotóxicos e genotóxicos. Os genes GSTM1 e GSTT1 são polimórficos em humanos e suas deleções têm sido associadas ao aumento do risco de várias neoplasias, dentre elas o câncer de mama. OBJETIVO: Comparar a freqüência das deleções dos genes GSTM1 e GSTT1 em mulheres sadias e com câncer de mama e comparar as características mamográficas do câncer entre mulheres portadoras e não portadoras das referidas deleções. MÉTODOS: Foram determinadas as freqüências das referidas deleções por PCR em 100 pacientes portadoras de câncer de mama esporádico tratadas de setembro de 2004 a junho de 2005 e em 169 mulheres sadias doadoras de sangue no mesmo período e comparadas através do odds ratio (OR) com seus respectivos IC 95 por cento. Foram revistos os prontuários e as mamografias das pacientes com câncer e avaliadas características mamográficas (padrão de distribuição do parênquima fibro-glandular, achados mamográficos ao diagnóstico e classificação BI-RADS), correlacionando-as às deleções gênicas através do cálculo da RP (razão de prevalência) com seus respectivos IC 95 por cento. RESULTADOS: O GSTM1 esteve deletado em 40 por cento dos cânceres e em 44,4 por cento dos controles (OR=1,20; IC 95 por cento 0,70-2,04; p=0,5659) enquanto o GSTT1 em 20 por cento e 19,5 por cento, respectivamente (OR=0,73; IC 0,37-1,44; p=0,4124). O padrão mamográfico denso esteve associado à deleção homozigótica do GSTM1 (RP= 2,43; IC 1,11-4,08). Não se observou associação entre as deleções do sistema GST e achados mamográficos ao diagnóstico e classificação BI-RADS. CONCLUSÃO: A deleção homozigótica do gene GSTM1 associou-se ao padrão mamográfico denso.

INTRODUCTION: Enzymes of the Glutathione S-transferase system (GST) modulate the effects of exposure to several cytotoxic and genotoxic agents. The GSTM1 and GSTT1 genes are polymorphic in humans and their deletions have been associated to increased risk of many cancers, including breast cancer. OBJECTIVE: To evaluate the occurrence of homozygous deletions of the GSTM1 and GSTT1 genes in women with sporadic breast cancer and in women without cancer and to compare breast cancer mammographic features between patients with and without these deletions. METHODS: The study evaluated 100 patients with sporadic breast cancer treated from September 2004 to June 2005 and 169 women without cancer, determining the frequency of the above-mentioned deletions by PCR and calculating the odds ratios and their 95 percent confidence intervals. Medical files and mammograms of 100 patients with breast cancer were evaluated and correlated with mammographic features such as density, mammographic findings and the BI-RADS classification. These findings were correlated with the genetic deletions by the PR (Prevalence-Ratio) with their respective 95 percent confidence intervals. RESULTS: The GSTM1 gene was deleted in 40 percent of the cancers and in 44.4 percent of controls (OR = 1.20; CI 95 percent 0.70 - 2.04; p=0.5659) while the GSTT1 gene was deleted in 20 percent and 19.5 percent, respectively (OR = 0.73; CI 95 percent 0.37-1.44; p=0.4124). High mammographic density had been associated with GSTM1 deletion (PR 2.43; CI 1.11 to 4.08). GST deletions were not associated with predominant mammographic findings and the BI-RADS classification. CONCLUSION: GSTM1 homozygous deletion was associated with high mammographic density.