Maria Dirlei Begnami

Molecular classifiers for gastric cancer and nonmalignant diseases of the gastric mucosa

High incidence of gastric cancer-related death is mainly due to diagnosis at an advanced stage in addition to the lack of adequate neoadjuvant therapy. Hence, new tools aimed at early diagnosis would have a positive impact in the outcome of the disease. Using cDNA arrays having 376 genes either identified previously as altered in gastric tumors or known to be altered in human cancer, we determined expression signature of 99 tissue fragments representing normal gastric mucosa, gastritis, intestinal metaplasia, and adenocarcinomas. We first validated the array by identifying molecular markers that are associated with intestinal metaplasia, considered as a transition stage of gastric adenocarcinomas of the intestinal type as well as markers that are associated with diffuse type of gastric adenocarcinomas. Next, we applied Fisher’s linear discriminant analysis in an exhaustive search of trios of genes that could be used to build classifiers for class distinction. Many classifiers could distinguish between normal and tumor samples, whereas, for the distinction of gastritis from tumor and for metaplasia from tumor, fewer classifiers were identified. Statistical validations showed that trios that discriminate between normal and tumor samples are powerful classifiers to distinguish between tumor and nontumor samples. More relevant, it was possible to identify samples of intestinal metaplasia that have expression signature resembling that of an adenocarcinoma and can now be used for follow-up of patients to determine their potential as a prognostic test for malignant transformation.

Overexpression of Fos-related antigen-1 in head and neck squamous cell carcinoma

The activating protein‐1 (AP‐1) family of transcription factors has been implicated in the control of proliferation and differentiation of keratinocytes, but its role in malignant transformation is not clear. The aim of this study is to assess the pattern of mRNA expression of jun‐fos AP‐1 family members in 45 samples of head and neck squamous cell carcinomas (HNSCC) and matched adjacent mucosa by means of Northern blot analysis. Transcripts of all family members were identified, except for JunB that was detected only by means of reverse transcription polymerase chain reaction. Neither c‐Fos nor JunD or FosB mRNA differed between tumours and normal tissues. We observed a strong Fos‐related antigen‐1 (Fra‐1) and Fra‐2 expression, but only Fra‐1 mRNA densitometric values were higher in tumour, compared to normal adjacent mucosa (t‐test, P = 0.006). A direct relationship between the positive expression of Fra‐1 mRNA, above tumour median, was associated with the presence of compromised lymph nodes (Fischer exact test, P = 0.006). In addition, Fra‐1 protein staining was assessed in a collection of 180 tumours and 29 histologically normal samples adjacent to tumours in a tissue array. Weak reactivity, restricted to the basal cell layer, was detected in 79% of tumour adjacent normal tissues, opposed to the intense reactivity of cancer tissues. In the subgroup of oral cancers, we have observed a shift in Fra‐1 immunoreactivity, as long as the number of patients in each category, cytoplasmic or nuclear/cytoplasmic staining, was analysed (Fischer exact test, P = 0.0005). Thus, Fra‐1 gene induction and accumulation of Fra‐1 protein may contribute to the neoplastic phenotype in HNSCC.

SAGE analysis highlights the importance of p53csv, ddx5, mapkapk2 and ranbp2 to multiple myeloma tumorigenesis

Serial analysis of gene expression (SAGE) allows a comprehensive profiling of gene expression within a given tissue and also an assessment of transcript abundance. We generated SAGE libraries from normal and neoplastic plasma cells to identify genes differentially expressed in multiple myeloma (MM). Normal plasma cells were obtained from palatine tonsils and MM SAGE library was generated from bone marrow plasma cells of MM patients. We obtained 29,918 SAGE tags from normal and 10,340 tags from tumor libraries. Computer-generated genomic analysis identified 46 upregulated genes in the MM library. Ten upregulated genes were selected for further investigation. Differential expression was validated by quantitative real-time PCR in purified plasma cells of 31 patients and three controls. P53CSV, DDX5, MAPKAPK2 and RANBP2 were found to be upregulated in at least 50% of the MM cases tested. All of them were also found upregulated in MM when compared to normal plasma cells in a meta-analysis using ONCOMINE microarray database. Antibodies specific to DDX5, RANBP2 and MAPKAPK2 were used in a TMA containing 57 MM cases and confirmed the expression of these proteins in 74%, 96%, and 21% of the MM samples, respectively. Analysis of differential expression using SAGE could identify genes important for myeloma tumorigenesis (P53CSV, DDX5, MAPKPK2 and RANBP2) and that could potentially be useful as therapeutic targets.

Cadherin-catenin adhesion system and mucin expression: a comparison between young and older patients with gastric carcinoma.

BackgroundYoung patients are thought to develop gastric carcinomas with a molecular genetic profile that is distinct from that of gastric carcinomas occurring at a later age. The aim of this study was to compare the clinicopathological features and expression patterns of the markers E-cadherin and β-catenin, and mucins (MUC1, MUC2, MUC5AC, and MUC6) in young and older patients.MethodsThe clinicopathological features and overall survival data of 62 young patients (age ≤40 years) with gastric cancer were retrospectively reviewed from hospital records and compared with the data for 453 older patients (age >40 years). A tissue microarray method and immunohistochemistry were used in order to analyze marker expression in paraffinembedded tissue blocks obtained from both groups.ResultsThe young group presented a higher percentage of diffuse-type tumors in comparison to the older group (P < 0.01). The rates of positivity for E-cadherin and β-catenin membranous expression patterns and mucin (MUC2, MUC5AC and MUC6) positivity were higher in the young group (P < 0.01). Although young patients showed a lower frequency of alterations in marker expression and had significantly better survival rates than the older patients, neither age nor the marker expression pattern were found to be independent prognostic factors of survival. Only stage, tumor size, and tumor location persisted as prognostic factors for patients with gastric cancer.ConclusionBiological markers of cellular adhesion and gastric differentiation were differently expressed in young and older patients. Our findings support the hypothesis that young patients develop carcinomas with a different genetic pathway compared to the pathway of tumors occurring at a later age, and we suggest further investigations to assess the prognostic relevance of the markers to specific subgroups.

Adjuvant chemoradiotherapy after d2-lymphadenectomy for gastric cancer: the role of n-ratio in patient selection. results of a single cancer center

BackgroundAdjuvant chemoradiotherapy is part of a multimodality treatment approach in order to improve survival outcomes after surgery for gastric cancer. The aims of this study are to describe the results of gastrectomy and adjuvant chemoradiotherapy in patients treated in a single institution, and to identify prognostic factors that could determine which individuals would benefit from this treatment.MethodsThis retrospective study included patients with pathologically confirmed gastric adenocarcinoma who underwent surgical treatment with curative intent in a single cancer center in Brazil, between 1998 and 2008. Among 327 patients treated in this period, 142 were selected. Exclusion criteria were distant metastatic disease (M1), T1N0 tumors, different multimodality treatments and tumors of the gastric stump. Another 10 individuals were lost to follow-up and there were 3 postoperative deaths. The role of several clinical and pathological variables as prognostic factors was determined.ResultsD2-lymphadenectomy was performed in 90.8% of the patients, who had 5-year overall and disease-free survival of 58.9% and 55.7%. The interaction of N-category and N-ratio, extended resection and perineural invasion were independent prognostic factors for overall and disease-free survival. Adjuvant chemoradiotherapy was not associated with a significant improvement in survival. Patients with node-positive disease had improved survival with adjuvant chemoradiotherapy, especially when we grouped patients with N1 and N2 tumors and a higher N-ratio. These individuals had worse disease-free (30.3% vs. 48.9%) and overall survival (30.9% vs. 71.4%).ConclusionN-category and N-ratio interaction, perineural invasion and extended resections were prognostic factors for survival in gastric cancer patients treated with D2-lymphadenectomy, but adjuvant chemoradiotherapy was not. There may be some benefit with this treatment in patients with node-positive disease and higher N-ratio.

Expressão imuno-histoquímica de c-erb-B2 e p53 em carcinomas gástricos

INTRODUCAO: Em nosso meio, os carcinomas gastricos ainda sao neoplasias bastante frequentes e responsaveis por altas taxas de mortalidade. Recentemente, tem-se demonstrado a expressao de p53 e a amplificacao do gene c-erb-B2 nos carcinomas gastricos. A relevância e o significado biologico destas alteracoes ainda nao foram totalmente estabelecidos. OBJETIVO: Estudar as expressoes imuno-histoquimicas de p53 e c-erb-B2 em 482 casos de carcinomas gastricos. MATERIAL E METODOS: Foram construidos tres blocos de tissue microarray (TMA) utilizando-se duplicatas de 482 casos de carcinomas gastricos. Os cortes foram corados por hematoxilina e eosina (HE), tendo sido feita pesquisa para p53 e c-erb-B2. Foram considerados positivos para p53 os casos com marcacao nuclear em mais de 10% das celulas tumorais. Para o c-erb-B2 foram considerados positivos os casos com marcacao de membrana completa em mais de 10% das celulas tumorais. RESULTADOS: A expressao de p53 e c-erb-B2 foi observada em 30% e 12% dos casos, respectivamente. Em relacao aos tipos histologicos observou-se correlacao entre os carcinomas do tipo intestinal e a expressao de c-erb-B2 (p < 0,001). A expressao de p53 foi mais frequente nos carcinomas com mais de 5cm de diâmetro (p = 0,036). Nao foram observadas alteracoes nas curvas de sobrevida dos pacientes em relacao as expressoes desses marcadores. CONCLUSAO: Em nosso meio, carcinomas gastricos do tipo intestinal sao mais frequentemente positivos para c-erb-B2 nos tipos intestinais do que nos difusos. A expressao de p53 esta associada ao tamanho tumoral. A tecnica do TMA e valida e eficiente para o estudo de marcadores imuno-histoquimicos, com forte correlacao com os cortes tradicionais de representacao do tumor.

Análise imuno-histoquímica das sintases do óxido nítrico em adenocarcinomas gástricos

INTRODUCTION: Nitric oxide is an important bioactive and signaling molecule that mediates a diverse array of actions such as vasodilatation, neurotransmission, and iron metabolism. Also, it can act as a carcinogen. Recent studies have examined the expression and activity of the NOS isoforms in several human cancers. OBJECTIVES: To investigate the expression of nitric oxide synthases in gastric carcinomas and correlate the results. MATERIAL AND METHODS: The immunohistochemistry expression of constitutive and inducible nitric oxide synthases (NOS-1, NOS-2 e NOS-3) were evaluated in 128 cases of gastric cancer classified according to Lauren system. RESULTS: The rate of expression of NOS-1 was 92 (70%) of the 12 cases, NOS-2 was 36 (30%) and NOS-3 was 54 (42%) of the cases. The expression of NOS-3 was associated with the intestinal type of carcinoma and deeply invasive tumors showed high rate of expression of NOS-2. CONCLUSION: There is high expression of all the isoforms of nitric oxide synthases in gastric cancer; the constitutive isoforms show higher expression than the inducible forms. The high expression of the inducible form in deeply invasive tumors is related with tumoral progression and dissemination in the gastric mucosa.

FIRST BRAZILIAN CONSENSUS ON MULTIMODAL TREATMENT OF COLORECTAL LIVER METASTASES. MODULE 1: PRE-TREATMENT EVALUATION

Background : Liver metastases of colorectal cancer are frequent and potentially fatal event in the evolution of patients with these tumors. Aim : In this module, was contextualized the clinical situations and parameterized epidemiological data and results of the various treatment modalities established. Method: Was realized deep discussion on detecting and staging metastatic colorectal cancer, as well as employment of imaging methods in the evaluation of response to instituted systemic therapy. Results : The next step was based on the definition of which patients would have their metastases considered resectable and how to expand the amount of patients elegible for modalities with curative intent. Conclusion : Were presented clinical, pathological and molecular prognostic factors, validated to be taken into account in clinical practice.

I CONSENSO BRASILEIRO DE TRATAMENTO MULTIDISCIPLINAR DE METÁSTASE HEPÁTICA COLORRETAIS. MÓDULO 1: AVALIAÇÃO PRÉ-TRATAMENTO

Racional : As metastases hepaticas de câncer colorretal sao evento frequente e potencialmente fatal na evolucao de pacientes com estas neoplasias. Objetivo : Neste modulo procurou-se contextualizar esta situacao clinica, bem como parametrizar dados epidemiologicos e de resultados das diversas modalidades de tratamento estabelecidas. Metodo : Foi realizada discussao sobre como detectar e estadiar o câncer colorretal metastatico, bem como o emprego dos metodos de imagem na avaliacao de resposta ao tratamento sistemico instituido. Resultado : Fundamentou na definicao de quais pacientes teriam suas metastases consideradas ressecaveis e de como se poderia ampliar a gama de pacientes submetidos as modalidades de tratamento ditas de intuito curativo. Conclusao : Foram apresentados os fatores prognosticos clinicos, patologicos e moleculares com validacao para serem levados em consideracao na pratica clinica.