RESUMO
Breast cancer is the second most common cancer worldwide and the first among women. Invasive ductal carcinoma (IDC) and invasive lobular carcinoma (ILC) are the two major histological subtypes, and the clinical and molecular differences between them justify the search for new markers to distinguish them. As proteomic analysis allows for a powerful and analytical approach to identify potential biomarkers, we performed a comparative analysis of IDC and ILC samples by using two-dimensional electrophoresis and mass spectrometry. Twenty-three spots were identified corresponding to 10 proteins differentially expressed between the two subtypes. ACTB, ACTG, TPM3, TBA1A, TBA1B, VIME, TPIS, PDIA3, PDIA6, and VTDB were upregulated in ductal carcinoma compared to in lobular carcinoma samples. Overall, these 10 proteins have a key role in oncogenesis. Their specific functions and relevance in cancer initiation and progression are further discussed in this study. The identified peptides represent promising biomarkers for the differentiation of ductal and lobular breast cancer subtypes, and for future interventions based on tailored therapy.
Assuntos
Biomarcadores Tumorais/genética , Neoplasias da Mama/genética , Carcinoma Ductal de Mama/genética , Carcinoma Lobular/genética , Proteoma/genética , Adulto , Idoso , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/metabolismo , Carcinoma Ductal de Mama/patologia , Carcinoma Lobular/metabolismo , Carcinoma Lobular/patologia , Diagnóstico Diferencial , Feminino , Humanos , Pessoa de Meia-Idade , Proteoma/metabolismoRESUMO
Changes in the expression of the protein disulfide isomerase genes PDIA3 and PDIA6 may increase endoplasmic reticulum stress, leading to cellular instability and neoplasia. We evaluated the expression of PDIA3 and PDIA6 in invasive ductal carcinomas. Using reverse transcription-quantitative polymerase chain reaction, we compared the mRNA expression level in 45 samples of invasive ductal carcinoma with that in normal breast samples. Increased expression of the PDIA3 gene in carcinomas (P = 0.0009) was observed. In addition, PDIA3 expression was increased in tumors with lymph node metastasis (P = 0.009) and with grade III (P < 0.02). The PDIA6 gene showed higher expression levels in the presence of lymph node metastasis (U = 99.00, P = 0.0476) and lower expression for negative hormone receptors status (P = 0.0351). Our results suggest that alterations in PDIA3/6 expression levels may be involved in the breast carcinogenic process and should be further investigated as a marker of aggressiveness.
Assuntos
Biomarcadores Tumorais/genética , Neoplasias da Mama/genética , Carcinoma Ductal de Mama/genética , Regulação Neoplásica da Expressão Gênica , Isomerases de Dissulfetos de Proteínas/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/metabolismo , Carcinoma Ductal de Mama/patologia , Feminino , Humanos , Metástase Linfática , Pessoa de Meia-Idade , Gradação de Tumores , Invasividade Neoplásica , Isomerases de Dissulfetos de Proteínas/metabolismo , Receptores de Estrogênio/genética , Receptores de Estrogênio/metabolismo , Receptores de Progesterona/genética , Receptores de Progesterona/metabolismoRESUMO
Oral squamous cell carcinoma (OSCC) is a worldwide health problem because it is a great cause of cancer morbidity and mortality. The transforming growth factor-ß1 (TGF-ß1) is involved in the regulation of numerous immunomodulatory processes. Thus, the aim of this case-control study was to investigate the possible association between the TGF-ß1T869C polymorphism and oral cancer. The genomic DNA extracted from peripheral blood of 62 male smoker patients diagnosed with OSCC and 62 smokers without cancer was analysed. The C allele was significantly more prevalent in the oral cancer group than in the controls, and individuals carrying this allele had an estimated 2.73-fold greater relative risk of developing cancer compared with C allele noncarriers (OR = 2.73, 95% CI = 1.19-6.28). Although T allele was not statistically significant among the controls, considering the genotypic analysis, the TT homozygous genotype showed a protector effect in relation to oral cavity cancer (OR = 0.37, 95% CI = 0.16-0.84). Some clinicopathological features were also analysed for genotype distribution, and no significant differences were observed: tumour size (P > 0.70), nodal status (P > 0.10) and tumour stage (P > 0.70). This is the first report of a study assessing the importance of T869C TGF-ß polymorphism in oral cancer. It is known that the TGF-ß T869C variation results in a Leu10Pro substitution in the signal peptide sequence. Our results suggested that the C allele could increase TGF-ß secretion which suppresses antitumour immune responses and may affect the OSCC risk.
Assuntos
Carcinoma de Células Escamosas/genética , Neoplasias Bucais/genética , Fator de Crescimento Transformador beta1/genética , Adulto , Alelos , Sequência de Bases , Carcinoma de Células Escamosas/imunologia , Estudos de Casos e Controles , Frequência do Gene , Marcadores Genéticos , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Neoplasias Bucais/imunologia , Polimorfismo de Nucleotídeo Único , Sinais Direcionadores de Proteínas/genética , Análise de Sequência de DNA , FumarRESUMO
Breast cancer is a complex and heterogeneous disease. In spite of the advances made in recent decades, a better understanding of the intrinsic mechanisms of this disease is crucial. The development of new biomarkers is absolutely necessary to improve diagnosis and prognosis. Research using the proteomic approach has generated interesting results; however, the complexity of the mammary gland and of breast tumors remains a major limitation to the development of new markers. An initial step is to characterize non-tumoral human breast tissue. We present data from classical proteomic analysis based on 2-D electrophoresis and peptide mass fingerprinting identification, which were performed on six non-tumoral samples from patients with invasive ductal breast carcinomas. Forty-four different proteins from 70 spots were identified and classified according to their biological function. Cytoskeleton and associated proteins represent the largest class (30%) followed by the proteins with binding function (27%). Several of the proteins have been described in breast tumors, such as vimentin, endoplasmin, small heat shock beta-6, disulfide isomerase and some cell growth, and proliferation regulators, suggesting the importance of including data on the characterization of non-tumoral breast and to studies on differential expression in cancer tissue.
Assuntos
Glândulas Mamárias Humanas/metabolismo , Proteoma/metabolismo , Proteômica , Idoso , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Carcinoma Ductal/diagnóstico , Carcinoma Ductal/metabolismo , Carcinoma Ductal/patologia , Feminino , Humanos , Glândulas Mamárias Humanas/patologia , Pessoa de Meia-Idade , PrognósticoRESUMO
Fanconi anemia is a rare hereditary disease showing genetic heterogeneity due to a variety of mutations in genes involved in DNA repair pathways, which may lead to different clinical manifestations. Phenotypic variability makes diagnosis difficult based only on clinical manifestations, therefore laboratory tests are necessary. New advances in molecular pathogenesis of this disease led researchers to develop a diagnostic test based on Western blot for FANCD2. The objective of the present study was to determine the efficacy of this method for the diagnosis of 84 Brazilian patients with Fanconi anemia, all of whom tested positive for the diepoxybutane test, and 98 healthy controls. The FANCD2 monoubiquitinated isoform (FANCDS+/FANCD2L-) was not detected in 77 patients (91.7%). In 2 patients (2.4%), there was an absence of both the monoubiquitinated and the non-ubiquitinated proteins (FANCD2S-/FANCD2L-) and 5 patients (5.9%) had both isoforms (FANCD2S+/FANCD2L+). This last phenotype suggests downstream subtypes or mosaicism. All controls were diepoxybutane negative and were also negative on the FANCD2 Western blot. The Western blot for FANCD2 presented a sensitivity of 94% (79/84) and specificity of 100% (98/98). This method was confirmed as an efficient approach to screen Brazilian patients with deleterious mutations on FANCD2 (FANCD2S-/FANCD2L-) or other upstream genes of the FA/BRCA pathway (FANCDS+/FANCD2L-), to confirm the chromosome breakage test and to classify patients according to the level of FA/BRCA pathway defects. However, patients showing both FANCD2 isoforms (FANCD2S+/FANCD2L+) require additional studies to confirm mutations on downstream Fanconi anemia genes or the presence of mosaicism.
Assuntos
Proteína do Grupo de Complementação D2 da Anemia de Fanconi/análise , Proteína do Grupo de Complementação D2 da Anemia de Fanconi/genética , Anemia de Fanconi/diagnóstico , Adolescente , Adulto , Western Blotting , Estudos de Casos e Controles , Criança , Pré-Escolar , Quebra Cromossômica , Compostos de Epóxi , Anemia de Fanconi/genética , Feminino , Marcadores Genéticos/genética , Humanos , Masculino , Fenótipo , Sensibilidade e Especificidade , Adulto JovemRESUMO
Fanconi anemia is a rare hereditary disease showing genetic heterogeneity due to a variety of mutations in genes involved in DNA repair pathways, which may lead to different clinical manifestations. Phenotypic variability makes diagnosis difficult based only on clinical manifestations, therefore laboratory tests are necessary. New advances in molecular pathogenesis of this disease led researchers to develop a diagnostic test based on Western blot for FANCD2. The objective of the present study was to determine the efficacy of this method for the diagnosis of 84 Brazilian patients with Fanconi anemia, all of whom tested positive for the diepoxybutane test, and 98 healthy controls. The FANCD2 monoubiquitinated isoform (FANCDS+/FANCD2L-) was not detected in 77 patients (91.7 percent). In 2 patients (2.4 percent), there was an absence of both the monoubiquitinated and the non-ubiquitinated proteins (FANCD2S-/FANCD2L-) and 5 patients (5.9 percent) had both isoforms (FANCD2S+/FANCD2L+). This last phenotype suggests downstream subtypes or mosaicism. All controls were diepoxybutane negative and were also negative on the FANCD2 Western blot. The Western blot for FANCD2 presented a sensitivity of 94 percent (79/84) and specificity of 100 percent (98/98). This method was confirmed as an efficient approach to screen Brazilian patients with deleterious mutations on FANCD2 (FANCD2S-/FANCD2L-) or other upstream genes of the FA/BRCA pathway (FANCDS+/FANCD2L-), to confirm the chromosome breakage test and to classify patients according to the level of FA/BRCA pathway defects. However, patients showing both FANCD2 isoforms (FANCD2S+/FANCD2L+) require additional studies to confirm mutations on downstream Fanconi anemia genes or the presence of mosaicism.
Assuntos
Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Adulto Jovem , /análise , /genética , Anemia de Fanconi/diagnóstico , Western Blotting , Estudos de Casos e Controles , Quebra Cromossômica , Compostos de Epóxi , Anemia de Fanconi/genética , Marcadores Genéticos/genética , Fenótipo , Sensibilidade e Especificidade , Adulto JovemRESUMO
The sentinel lymph node (SLN) is considered to be the first axillary node that contains malignant cells in metastatic breast tumors, and its positivity is currently used in clinical practice as an indication for axillary lymph node dissection. Therefore, accurate evaluation of the SLN for the presence of breast metastatic cells is essential. The main aim of our study is to characterize the genomic changes present in the SLN metastatic samples with the ultimate goal of improving the predictive value of SLN evaluation. Twenty paired samples of SLN metastases and their corresponding primary breast tumors (PBT) were investigated for DNA copy number changes using comparative genomic hybridization (CGH). Non-random DNA copy number changes were observed in all the lesions analyzed, with gains being more common than losses. In 75% of the cases there was at least one change common to both PBT and SLN. The most frequent changes detected in both lesions were gains of 1pter-->p32, 16, 17, 19, and 20 and losses of 6q13-->q23 and 13q13-->q32. In the PBT group, alterations on chromosomes 1, 16, and 20 were the most frequent, whereas chromosomes 1, 6, and 19 were the ones with the highest number of changes in the SLN metastatic group. A positive correlation was found between the DNA copy number changes per chromosome in each of the groups. Our findings indicate the presence of significant DNA copy number changes in the SLN metastatic lesions that could be used in the future as additional markers to improve the predictive value of SLN biopsy procedure.
Assuntos
Neoplasias da Mama/genética , DNA de Neoplasias/genética , Metástase Linfática/genética , Adulto , Idoso , Neoplasias da Mama/secundário , Mapeamento Cromossômico , DNA de Neoplasias/análise , Feminino , Dosagem de Genes , Humanos , Cariotipagem , Pessoa de Meia-Idade , Análise de Sequência com Séries de Oligonucleotídeos , Biópsia de Linfonodo SentinelaRESUMO
The cytochrome P450 family (CYPs) and the glutathione S-transferase (GSTs) enzymes play an important role in the metabolism of environmental carcinogens and of oestrogen and can affect breast cancer risk. In this study we examine the role of the genes CYP1A1, CYP17, CYP2D6, GSTM1, GSTP1 and GSTT1 in breast cancer risk in Brazilian women. The study population consisted of 102 incident breast cancer cases and 102 healthy controls. Genotyping analyses were performed by PCR-based methods. A significant finding was observed between GSTP1 Ile-Val polymorphism and breast cancer risk (OR = 1.81; CI 95% = 1.04-3.16). A significant association was observed between women with 0-2 risk genotypes and those with 4 or more risk genotypes (OR = 2.42; CI 95% = 1.13-5.18) when the potential combined effects of the risk genotypes were examined. No significant differences between cases and controls were found correlating the genotypes and the clinical-histopathological parameters. In conclusion, in our population only GSTP1 was associated with breast cancer risk. However, when the genes were tested in combination, a significant association in the breast cancer risk was observed.
Assuntos
Neoplasias da Mama/etiologia , Sistema Enzimático do Citocromo P-450/genética , Estrogênios/metabolismo , Glutationa Transferase/genética , Polimorfismo Genético , Adulto , Idoso , Neoplasias da Mama/genética , Feminino , Genótipo , Humanos , Redes e Vias Metabólicas , Pessoa de Meia-IdadeRESUMO
CYP1A1 and GSTP1 polymorphisms have been associated with a higher risk to develop several cancers, including oral squamous cell carcinoma (OSCC), which is closely related to tobacco and alcohol consumption. Both genes code for enzymes that have an important role in activating or detoxifying carcinogenic elements found in tobacco and other compounds, and polymorphic variants of these genes may result in alterations of the enzymatic activity. The CYP1A1 gene codes for the enzyme aryl hydrocarbon hydroxylase, which is responsible for the metabolism of polycyclic aromatic hydrocarbons. The investigated polymorphism, Ile/Val, seems to increase the activity of the enzyme in homozygous individuals, leading to an accumulation of carcinogens. The Ile/Val polymorphism occurs because of an A->G transition at exon 7, resulting in the CYP1A1*2B allele. The GSTP1*B variant shows an A->G transition at exon 5, changing the amino acid Ile to Val, with a reduced catalytic activity of the enzyme. Due to this reduction, the carriers of mutant alleles lost the capability to metabolize carcinogens, which could be responsible for a higher susceptibility to cancer. We conducted a case-control study in a group of 72 cases with newly diagnosed OSCC and 60 healthy controls matched for age, gender, smoking habits, and ethnicity. We used PCR methods to identify the allelic variants CYP1A1*2B and GSTP1*B. The data obtained showed no statistically significant association of allelic or genotypic variants of CYP1A1*2B (OR = 1.06; 95% CI = 0.49-2.29) and GSTP1*B (OR = 1.40; 95% CI = 0.70-2.79) with OSCC.
Assuntos
Citocromo P-450 CYP1A1/genética , Glutationa S-Transferase pi/genética , Neoplasias Bucais/genética , Neoplasias de Células Escamosas/genética , Polimorfismo Genético/genética , Alelos , Estudos de Casos e Controles , Feminino , Frequência do Gene/genética , Marcadores Genéticos/genética , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/enzimologia , Neoplasias de Células Escamosas/enzimologia , Reação em Cadeia da Polimerase , Fatores de RiscoRESUMO
CYP1A1 and GSTP1 polymorphisms have been associated with a higher risk to develop several cancers, including oral squamous cell carcinoma (OSCC), which is closely related to tobacco and alcohol consumption. Both genes code for enzymes that have an important role in activating or detoxifying carcinogenic elements found in tobacco and other compounds, and polymorphic variants of these genes may result in alterations of the enzymatic activity. The CYP1A1 gene codes for the enzyme aryl hydrocarbon hydroxylase, which is responsible for the metabolism of polycyclic aromatic hydrocarbons. The investigated polymorphism, Ile/Val, seems to increase the activity of the enzyme in homozygous individuals, leading to an accumulation of carcinogens. The Ile/Val polymorphism occurs because of an A->G transition at exon 7, resulting in the CYP1A1*2B allele. The GSTP1*B variant shows an A->G transition at exon 5, changing the amino acid Ile to Val, with a reduced catalytic activity of the enzyme. Due to this reduction, the carriers of mutant alleles lost the capability to metabolize carcinogens, which could be responsible for a higher susceptibility to cancer. We conducted a case-control study in a group of 72 cases with newly diagnosed OSCC and 60 healthy controls matched for age, gender, smoking habits, and ethnicity. We used PCR methods to identify the allelic variants CYP1A1*2B and GSTP1*B. The data obtained showed no statistically significant association of allelic or genotypic variants of CYP1A1*2B (OR = 1.06; 95 percent CI = 0.49-2.29) and GSTP1*B (OR = 1.40; 95 percent CI = 0.70-2.79) with OSCC.