Genomic imbalances in esophageal squamous cell carcinoma identified by molecular cytogenetic techniques

This review summarizes the chromosomal changes detected by molecular cytogenetic approaches in esophageal squamous cell carcinoma (ESCC), the ninth most common malignancy in the world. Whole genome analyses of ESCC cell lines and tumors indicated that the most frequent genomic gains occurred at 1, 2q, 3q, 5p, 6p, 7, 8q, 9q, 11q, 12p, 14q, 15q, 16, 17, 18p, 19q, 20q, 22q and X, with focal amplifications at 1q32, 2p16-22, 3q25-28, 5p13-15.3, 7p12-22, 7q21-22, 8q23-24.2, 9q34, 10q21, 11p11.2, 11q13, 13q32, 14q13-14, 14q21, 14q31-32, 15q22-26, 17p11.2, 18p11.2-11.3 and 20p11.2. Recurrent losses involved 3p, 4, 5q, 6q, 7q, 8p, 9, 10p, 12p, 13, 14p, 15p, 18, 19p, 20, 22, Xp and Y. Gains at 5p and 7q, and deletions at 4p, 9p, and 11q were significant prognostic factors for patients with ESCC. Gains at 6p and 20p, and losses at 10p and 10q were the most significant imbalances, both in primary carcinoma and in metastases, which suggested that these regions may harbor oncogenes and tumor suppressor genes. Gains at 12p and losses at 3p may be associated with poor relapse-free survival. The clinical applicability of these changes as markers for the diagnosis and prognosis of ESCC, or as molecular targets for personalized therapy should be evaluated

Expression of Ki-67 Antigen and Caspase-3 Protein in Benign Lesions and Esophageal Carcinoma

Background: The present study aimed to evaluate apoptosis and cell proliferation alterations in esophageal benign lesions in comparison to esophageal carcinomas. Materials and Methods: Immunohistochemistry was performed for caspase-3 protein (CPP32) and Ki-67 antigen expression in the esophageal mucosa from patienis with Chagas disease (CD) with and without megaesophagus (CM), chronic esophagitis (CE), esophageal carcinoma (ESCC) and in normal mucosa (NM). Results: The Ki-67 labeling index (LI) was similar in all groups (range: 30%-48%), having no statistically significant difference among the groups. Positive CPP32 immunostaining was observed with similar frequency in the CD (30.8%), CM (30.4%) and CE (34.8%) groups, but it was increased in the ESCC group (55.5%); however, it was not statistically different from the other groups. No associations among the levels of CPP32 and Ki-67 expression were observed in the various groups, neither among parameters such as age, gender or alcohol and tobacco consumption. Conclusion: There were no evident changes in cell proliferation and apoptosis in benign lesions studied.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

In vitro metabolism effect on genotoxicity and antigenotoxicity of Agaricus blazei organics and aqueous extracts by the comet assay

There is high interest in the natural products properties due to their use in popular medicine. Agaricus blazei Murrill ss. Heinem. (Ab) is native to Brazil and has been widely disseminated because its medicinal properties. In the present study, the genotoxic and antigenotoxic potential of Ab extracts were investigated using the comet assay. The cells utilized were the non drug-metabolizing line CHO-k1 (Chinese hamster ovary) and the drug-metabolizing line HTC (rat hepatoma). Cells were treated for 3 h in the absence of fetal bovain serum (FBS) with methanolic, hexanic and n-butanolic extracts at 50 μg/ml and 0.75% aqueous extract to test for genotoxicity. Antigenotoxic effects of extracts were determined in cells exposed to the DNA damage inducing agent ethyl methanesulfonate under simultaneous or simultaneous with 1 h pre-incubation conditions. The extracts did not show genotoxicity in HTC, while they were genotoxic in CHO-k1. No antigenotoxic effect was observed with any extract under any condition. These results demonstrate that the metabolism in presence or in absence has a direct influence on the genotoxicity of these extracts. © 2006 The Japan Mendel Society

beta-Glucan extracted from the medicinal mushroom Agaricus blazei prevents the genotoxic effects of benzo[a]pyrene in the human hepatoma cell line HepG2

The mushroom Agaricus blazei is studied for its nutraceutical potential and as a medicinal supplement. The aim of the present study was to investigate the chemoprotective effect of beta-glucan extracted from the mushroom A. blazei against DNA damage induced by benzo[a]pyrene (B[a]P), using the comet assay (genotoxicity) and micronucleus assay with cytokinesis block (mutagenicity) in a human hepatoma cell line (HepG2). To elucidate the possible beta-glucan mechanism of action, desmutagenesis or bioantimutagenesis types, three treatment protocols were tested: simultaneous, pre-treatment, and presimultaneous. The results showed that beta-glucan does not exert genotoxic or mutagenic effect, but that it does protect against DNA damage caused by B[a]P in every protocol tested. The data suggest that beta-glucan acts through binding to B[a]P or the capture of free radicals produced during its activation. on the other hand, the pre-treatment results also suggest the possibility that beta-glucan modulates cell metabolism.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

p53, p16 and Fhit Proteins Expressions in Chronic Esophagitis and Chagas Disease

Background: Models have suggested esophageal carcinogenesis can result front the alteration of sequences, leading to esophagitis, atrophy, dysplasia, carcinoma in situ and invasive carcinoma. While numerous genetic alterations have been reported in esophageal carcinogenesis, studies of benign lesions with precancerous potential are scarce. Materials and Methods: Immunohistochemistry was performed for p53, p16 and Fhit proteins in the esophageal mucosa from patients with Chagas disease (CD), chagasic megaesophagus (CM), chronic esophagitis (CE), esophageal squamous cell carcinoma (ESCC) and in normal mucosa (NM). Results: The proportion of p53-positive cases increased progressively according to the severity of the pathology CD (7.7%), CM (26.1%), CE (52.2%) and ESCC (100%). However, p16 and Fhit did not show any statistically significant differences among the groups. Conclusion: p53 overexpression is involved in the initial steps of esophageal carcinogenesis, supporting further evaluation of its utility as a marker in precursor lesions, conversely, losses of Fhit and p16 expression may not be significant.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Alterations of the TP53 Gene in Gastric and Esophageal Carcinogenesis

TP53 genes is one of more important tumor suppressor gene, which acts as a potent transcription factor with fundamental role in the maintenance of genetic stability. The development of esophageal and gastric cancers is a multistep process resulting in successive accumulation of genetic alterations that culminates in the malignant transformation. Thus, this study highlights the participation of the main genetic alterations of the TP53 gene in esophageal and gastric carcinogenesis. Among these changes, high frequency of TP53 mutations, loss of heterozygosity (LOH), overexpression of the p53 protein, and consequently loss of p53 function, which would be early events in esophageal and gastric cancers, as well as an important biomarker of the prognosis and treatment response. Furthermore, Single Nucleotide Polymorphisms (SNPs) of TP53 have been implicated in the development and prognosis of several cancers, mainly TP53 codon 72 polymorphism whose role has been extensively studied in relation to susceptibility for esophageal and gastric cancer development.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Cytotoxicity and genotoxicity of Agaricus blazei methanolic extract fractions assessed using gene and chromosomal mutation assays

Functional food investigations have demonstrated the presence of substances that could be beneficial to human health when consumed. However, the toxic effects of some substances contained in foods have been determined. Reported medicinal and nutritive properties have led to the extensive commercialization of the basidiomycete fungi Agaricus blazei Murrill (sensu Heinemann), also known as Agaricus brasiliensis Wasser et al., Agaricus subrufescens Peck or the Brazilian medical mushroom (BMM). Different methanolic extract fractions (ME) of this mushroom were submitted to the cytokinesis-block micronucleus (CBMN) clastogenic assay and the hypoxanthine-guanine phosphoribosyl transferase locus (HGPRT) assay for gene mutation, both using Chinese hamster ovary cells clone K1 (CHO-K1). The results suggest that all the fractions tested possess cytotoxic and mutagenic potential but no clastogenic effects. Further information is needed on the biochemical components of the A. blazei methanol fractions to identify any substances with cytotoxic and/or mutagenicity potential. These findings indicate that A. blazei methanolic extract should not be used due to their genotoxicity and care should be taken in the use of A. blazei by the general population until further biochemical characterization of this fungi is completed.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Cardiomyopathy and cell therapy: ejection fraction improvement and cardiac muscle mass increasing, after a year of bone marrow stem cells transplantation, by magnetic resonance image

The idiopathic dilated cardiomyopathy (IDC) is one of the major public health problems in the western world. Patients with IDC in functional class IV (New York Health Association - NYHA), even after therapeutic optimization, have high mortality. Stem cell therapy has emerged as a potential therapeutic option for cell death-related heart diseases and several positive effects were assigned to cell therapy in cardiomyopathy. The aim of this study was identify short-term result of cell transplantation in idiopathic dilated cardiomyopathy patients (IDC) who were treated by transplantation of autologous bone marrow mononuclear cells (BMMC). Intracoronary injections of autologous BMMC were performed in eight patients with severe ventricle dysfunction (mean of left ventricle ejection fraction – LEVF=20.03%), cardiac mass muscle around 156.2 g and NYHA between III and IV grades, other 8 IDC patients received placebo. The IDCs were followed - up for one and two years, by magnetic resonance imaging (MRI). The results after one year showed significant improvement in LVEF (mean=181.4) and muscle mass increasing (mean=181.4 g), after two years the LVEF continued improving, reaching a mean of 32.69% and the cardiac muscle mass kept stable (mean=179.4 g). Excepted for one patient, all the other had improvement in the NYHA functional class. The placebo group did not show any improvement. We believe that BMMC implant may be a beneficial therapeutic option for IDC patients