Análise comparativa do polimorfismo genético da glutationa transferase, do Helicobacter pylori e do vírus Epstein-Barr entre a área do tumor e as margens de ressecção proximal e distal do câncer gástrico / Comparative analysis of glutathione transferase genetic polymorphism, Helicobacter pylori and Epstein-Barr virus between the tumor area and the proximal and distal resection margins of gastric cancer

RESUMO Objetivo: comparar o polimorfismo dos genes Glutationa S-transferase teta 1 (GSTT1) e Glutationa S-transferase mu 1 (GSTM1) da área do tumor com as margens proximal e distal de espécimes de estômago ressecados de pacientes com câncer gástrico, e investigar a presença do DNA do vírus Epstein-Barr (EBV) e Helicobacter pylori. Métodos: coletamos prospectivamente amostras teciduais da área do tumor e das margens de ressecção proximal e distal dos estômagos de dez pacientes com adenocarcinoma gástrico submetidos à gastrectomia com linfadenectomia D2 e submetemos esses espécimes à extração de DNA. Comparamos a área do tumor com as margens proximal e distal dos estômagos ressecados para o polimorfismo dos genes GSTT1 e GSTM1 e investigamos a presença de DNA do EBV e H. pylori. Utilizamos o exon 5 do gene p53 como controle interno da reação de PCR multiplex. Resultados: em um paciente, detectamos genótipos GSTT1 e GSTM1 nulos na área do tumor, em contraste com a presença de ambos os genes nas margens proximal e distal. Encontramos DNA do EBV e H. pylori na área do tumor e também nas margens proximal e distal. Em outro paciente, a margem proximal foi negativa para GSTT1 e o DNA do EBV foi negativo na margem distal. Em três pacientes, o EBV-DNA foi negativo apenas na margem distal. Conclusão: este é o primeiro relato em que diferentes genótipos, infecção por EBV-DNA e H. pylori foram observados no mesmo paciente, indicando provável deleção desses genes em resposta à progressão tumoral e heterogeneidade intratumoral.

ABSTRACT Objective: to compare the polymorphism of the Glutathione S-transferase theta 1 (GSTT1) and Glutathione S-transferase mu 1 (GSTM1) genes from the tumor area with the proximal and distal margins of stomach specimens resected from patients with gastric cancer, and to investigate the presence of Epstein-Barr virus (EBV) DNA and Helicobacter pylori. Methods: we prospectively collected tissue specimens from the tumor area and from the proximal and distal resection margins of the stomachs of ten patients with gastric adenocarcinoma who underwent gastrectomy with D2 lymphadenectomy, and submitted these specimens to DNA extraction. We compared the tumor area with the proximal and distal margins of the resected stomachs for polymorphism of GSTT1 and GSTM1 genes and investigated the presence of EBV-DNA and H. pylori. We used the p53 exon 5 gene as an internal control of the multiplex PCR reaction. Results: in one patient, we detected null GSTT1 and GSTM1 genotypes in the tumor area, in contrast to the presence of both genes in the proximal and distal margins. We found EBV-DNA and H. pylori in the tumor area and also in the proximal and distal margins. In another patient, the proximal margin was negative for GSTT1, and EBV-DNA was negative in the distal margin. In three patients, EBV-DNA was negative only in the distal margin. Conclusion: this is the first report where different genotypes, EBV-DNA and H. pylori infection were observed in the same patient, indicating a probable deletion of these genes in response to tumor progression and intratumoral heterogeneity.

Molecular evidence of high-risk human papillomavirus infection in colorectal tumours from Cuban patients

The association between colorectal cancer and human papillomavirus (HPV) infection is still unproven. The aim of this study was to investigate the presence of high-risk HPV (HR-HPV) DNA in colorectal tissues from Cuban patients. A total of 63 colorectal formalin-fixed paraffin-embedded tissues were studied (24 adenocarcinoma, 18 adenoma, and 21 colorectal tissues classified as benign colitis). DNA from colorectal samples was analysed by quantitative real-time polymerase chain reaction to detect the most clinically relevant high HR-HPV types (HPV-16, -18, -31, -33, -45, -52, and -58). Associations between histologic findings and other risk factors were also analysed. Overall, HPV DNA was detected in 23.8% (15/63) of the samples studied. Viral infections were detected in 41.7% of adenocarcinoma (10/24) and 27.7% of adenoma cases (5/18). HPV DNA was not found in any of the negative cases. An association between histological diagnosis of adenocarcinoma and HPV infection was observed (odd ratio = 4.85, 95% confidence interval = 1.40-16.80, p = 0.009). The only genotypes identified were HPV 16 and 33. Viral loads were higher in adenocarcinoma, and these cases were associated with HPV 16. This study provides molecular evidence of HR-HPV infection in colorectal adenocarcinoma tissues from Cuban patients.

Epstein-Barr virus-positive gastric cancer: a distinct molecular subtype of the disease?

Abstract: Approximately 90% of the world population is infected by Epstein-Barr virus (EBV). Usually, it infects B lymphocytes, predisposing them to malignant transformation. Infection of epithelial cells occurs rarely, and it is estimated that about to 10% of gastric cancer patients harbor EBV in their malignant cells. Given that gastric cancer is the third leading cause of cancer-related mortality worldwide, with a global annual incidence of over 950,000 cases, EBV-positive gastric cancer is the largest group of EBV-associated malignancies. Based on gene expression profile studies, gastric cancer was recently categorized into four subtypes; EBV-positive, microsatellite unstable, genomically stable and chromosomal instability. Together with previous studies, this report provided a more detailed molecular characterization of gastric cancer, demonstrating that EBV-positive gastric cancer is a distinct molecular subtype of the disease, with unique genetic and epigenetic abnormalities, reflected in a specific phenotype. The recognition of characteristic molecular alterations in gastric cancer allows the identification of molecular pathways involved in cell proliferation and survival, with the potential to identify therapeutic targets. These findings highlight the enormous heterogeneity of gastric cancer, and the complex interplay between genetic and epigenetic alterations in the disease, and provide a roadmap to implementation of genome-guided personalized therapy in gastric cancer. The present review discusses the initial studies describing EBV-positive gastric cancer as a distinct clinical entity, presents recently described genetic and epigenetic alterations, and considers potential therapeutic insights derived from the recognition of this new molecular subtype of gastric adenocarcinoma.

Frecuencia de virus papiloma humano en tumores no ginecológicos de la Región de la Araucanía, Chile / Human papilloma virus frequency in non-gynecological tumors in the Araucanía Region, Chile

El Virus Papiloma Humano (HPV por sus siglas en inglés) es una de las infecciones de transmisión sexual más frecuentes del mundo y se encuentra presente en la mayoría de los cánceres de cuello uterino. Se ha descrito su presencia en otros tipos de cáncer no ginecológicos como lo son esófago y próstata. Sin embargo, las frecuencias de HPV descritas hasta el momento para estos tipos de cáncer son muy variables, y no hay artículos donde se muestren la presencia de HPV en estas neoplasias en Chile. El objetivo de este estudio fue determinar la frecuencia de HPV en muestras de biopsias de tumores no ginecológicos y tejido inflamatorio de pacientes de la región de La Araucanía. Se extrajo DNA desde un total de 47 biopsias de pacientes con esofagitis, 25 con carcinoma escamoso esofágico, 20 con hiperplasia nodular de la próstata y 39 con adenocarcinoma prostático. Estas fueron analizadas por PCR de la región L1 del virus y posterior genotipificación por reverse line blot. Se detectó HPV en el 53,2% de las muestras de esofagitis, 48% en muestras de carcinoma escamoso esofágico, 15% en hiperplasia nodular de la próstata y un 15,4% en los casos de adenocarcinoma prostático. Siendo los más frecuentes los genotipos de HPV 16 y 18, ya sea en infecciones simples o junto con otros genotipos, en lesiones preneoplásicas y neoplásicas de los tejidos estudiados. Existe una alta frecuencia de infección por HPV en biopsias de esofagitis y tejido inflamatorio esofágico de pacientes de la región de la Araucanía. En los casos de adenocarcinoma prostático e hiperplasia nodular de la próstata se observa una baja frecuencia de HPV.

Human Papilloma Virus (HPV) is the most common sexually transmitted disease in the world and it is present in practically all cervical cancers. Its presence was described in other types of non-gynecologic cancer such as esophageal and prostate. However, HPV frequency described for these cancers is highly variable, and there are no articles describing the presence of HPV in these tumors in Chile. To determine HPV frequency in samples from biopsies of non-gynecological tumors and inflammatory tissue from patients in the Araucanía region, DNA was extracted from a total of 47 biopsies from patients with esophagitis, 25 with esophageal squamous cell carcinoma, 20 with prostate nodular hyperplasia and 39 with prostate adenocarcinoma. These were analyzed by PCR of HPV L1 region and subsequent genotyping by reverse line blot. HPV was detected in 53.2% of esophagitis samples, 48% in esophageal squamous cell carcinoma, 15% in prostatitis and 15.4% in cases of prostatic adenocarcinoma. The most frequent HPV genotypes were 16 and 18, either single or in combination with other genotype infections, in inflammatory tissue and neoplastic lesions. In patients of the Araucanía region, there is a high rate of HPV infection in biopsies obtained in esophagitis and esophageal inflammatory tissue. In cases of prostatic adenocarcinoma and prostate nodular hyperplasia a low rate of HPV was observed.

Association between human Papillomavirus and colorectal adenocarcinoma and its influence on tumor staging and degree of cell differentiation / Associação do Papilomavírus humano com o adenocarcinoma colorretal e sua influência no estadio tumoral e no grau de diferenciação celular

BACKGROUND: Colorectal cancer is one of the most common types of neoplasia among the worldwide adult population. Among neoplasms of the gastrointestinal tract, it is ranked second in relation to prevalence and mortality, but its etiology is only known in around 5% of the cases. It is believed that 15% of malignant diseases are related to viral oncogenesis. AIM: To correlate the presence of HPV with the staging and degree of cell differentiation among patients with colorectal adenocarcinoma. METHODS: A retrospective case-control study was conducted on 144 patients divided between a test group of 79 cases of colorectal cancer and a control group to analyze 144 patients aged 25 to 85 years (mean, 57.85 years; standard deviation, 15.27 years and median, 58 years). Eighty-six patients (59.7%) were male. For both groups, tissue samples from paraffin blocks were subjected to DNA extraction followed by the polymerase chain reaction using generic and specific primers for HPV 16 and 18. Dot blot hybridization was also performed with the aim of identifying HPV DNA. RESULTS: The groups were shown to be homogenous regarding sex, age and site of HPV findings in the samples analyzed. Out of the 41 patients with HPV, 36 (45.6%) were in the cases and five (7.7%) were in the control group (p<0.001). All the HPV cases observed comprised HPV 16, and HPV 18 was not shown in any of the cases studied. There were no significant differences in comparisons of sex, age and site regarding the presence of HPV in either of the groups. It was not observe any significant difference in relation to staging or degree of cell differentiation among the patients with colorectal cancer. CONCLUSION: Human papillomavirus type 16 is present in individuals with colorectal carcinoma. However, its presence was unrelated to staging or degree of differentiation. .

RACIONAL: O câncer colorretal é uma das neoplasias mais frequentes entre a população adulta mundial, e entre as do trato gastrointestinal, é a segunda em relação à prevalência e mortalidade sendo a sua causa conhecida apenas em cerca de 5% dos casos. Acredita-se que 15% das doenças malignas estariam relacionadas à oncogênese viral. OBJETIVO: Correlacionar a presença do HPV com o estadiamento e o grau de diferenciação celular dos pacientes portadores de adenocarcinoma colorretal. MÉTODOS: Foi realizado um estudo retrospectivo do tipo caso-controle com 144 pacientes divididos em um grupo teste representado por pacientes com câncer colorretal em um total de 79 casos e um grupo controle correspondente à pacientes com doença benigna totalizando 65 casos. Após a aplicação dos critérios de exclusão, foi possível analisar 144 pacientes com idade entre 25 a 85 anos (média de 57,85 anos com desvio-padrão de 15,27 anos e mediana de 58 anos). Oitenta e seis (59,7%) pacientes eram homens. Amostras teciduais a partir de blocos de parafina de ambos os grupos foram submetidos à extração do DNA e em seguida foi realizada reação em cadeia da polimerase com iniciadores genéricos e específicos para HPV 16 e 18 e também a hibridização do tipo dot blot com o intuito de identificar o DNA do HPV. RESULTADOS: Os grupos se mostraram homogêneos quanto a sexo, idade e localização do HPV nas amostras analisadas. Dos 41 pacientes com HPV, 36 (45,6%) eram do grupo teste e cinco (7,7%) do grupo controle (p<0,001). Todos os casos de HPV observados correspondiam ao HPV 16 não sendo evidenciado HPV 18 em nenhum caso estudado. Não houve diferença significativa na comparação realizada quando se considerou o sexo, idade e localização ...

Human papilloma virus screening by hybrid capture II in chinese women of Jiangsu Province / Tamizaje del virus del papiloma humano mediante captura híbrida en mujeres chinas de la Provincia de Jiangsu

OBJECTIVE: To survey Human Papilloma Virus (HPV) infection in Chinese Women of Jiangsu Province and discuss the relationship between HPV and the biology of cervical cancer. METHODS: Two thousand, one hundred and fifty-three sexually active women (including 66 cases of cervical cancer) were selected for high-risk human papilloma virus DNA test with Hybrid Capture II (HCII). RESULTS: The overall HPV prevalence was 32.6% (701/2153) with higher positive rates in cervical carcinoma and Cervical Interstitial Neoplasia (CIN) [93.9% and 54.6%] respectively. For women aged 40-59 years, the overall high-risk HPV prevalence was higher than those of other age groups. Compared with CIN I, the positivity rate and viral load of HPV DNA in CIN III is much higher (80.2% vs 29.9%, 11.89 vs 0.53). Ninety-four per cent (64/66) of patients with Cervical cancer were detected to be HPV positive. There was no significant difference in HPV DNA among each clinical stage and pathologic grade. But the positive rates and the value of HPV DNA were higher in the patients with cervical interstitial incursion. Eighty per cent of patients (20/25) could become negative within six months after operation. CONCLUSIONS: High-risk HPV DNA test is effective in screening for cervical diseases. HC II is an effective method to detect HPV DNA.

OBJETIVO: Investigar la infección por el virus del papiloma humano (VPH) en las mujeres chinas de la Provincia de Jiangsu y analizar la relación entre VPH y la biología del cáncer cervical o del cuello uterino. MÉTODOS: Dos mil ciento cincuenta y tres mujeres sexualmente activas (incluyendo 66 casos de cáncer cervical) fueron seleccionadas para una prueba de ADN con el fin de detectar el virus del papiloma humano de alto riesgo mediante Captura Híbrida 2 (HC2). RESULTADOS: La prevalencia general de VPH fue 32.6% (701/2153), hallándose las tasas positivas más altas en el carcinoma cervical y la neoplasia intersticial cervical (NIC) [93.9% y 54.6%]. Para las mujeres de 40-59 años de edad, la prevalencia general de VPH de alto riesgo fue mayor que para los otros grupos etarios. En comparación con el CIN, la tasa de positividad y la carga viral de ADN del VPH en el CIN es mucho mayor (80.2% vs 29.9%, 11.89 vs 0.53). Se detectó que noventa y cuatro por ciento (64/66) de las pacientes con cáncer del cuello uterino eran VPH positivas. No hubo ninguna diferencia significativa en el ADN del VPH ADN entre cada fase clínica y el grado patológico. No obstante, tanto las tasas positivas como el valor de VPH ADN fueron más altos en las pacientes con incursión intersticial cervical. Ochenta por ciento de las pacientes (20/25) podrían volverse negativas en seis meses tras la operación. CONCLUSIONES: La prueba de ADN para la detección del virus del papiloma humano de alto riesgo es un medio efectivo para el tamizaje de las enfermedades cervicales. El HC2 es un método efectivo para detectar el ADN del VPH.

Genotipificación del virus papiloma humano en mujeres con adenocarcinoma cervical de la Región de La Araucanía-Chile / Human papillomavirus genotyping in cervical adenocarcinoma in the Region of La Araucanía-Chile

El virus papiloma humano (VPH) es el principal factor causal del cáncer cervicouterino (CCU). Así, detectar y genotipificar el VPH es importante para conocer la frecuencia de los genotipos presentes en la región. En este trabajo se estudiaron 44 biopsias de adenocarcinoma cervical (ACC). Para la detección del VPH se empleó una reacción de polimerasa en cadena anidada dirigida al gen L1 (RPCL1), para la genotipificación viral se utilizaron enzimas de restricción (Rsa I, Dde I, Pst I) y secuenciación. Se detectó ADN viral mediante RPCL1 anidada en 100 por ciento de las biopias. Se logró tipificar 38/44 casos: 81,6 por ciento VPH 16; 13,2 por ciento VPH 18; 2,6 por ciento VPH 33 y 2,6 por ciento VPH 18/33. Conclusiones: La metodología fue exitosa para identificar el tipo viral en 86 por ciento de las biopsias. Se observó una estrecha asociación ACC-VPH, especialmente con el tipo viral 16, detectado en 81,6 por ciento de los casos tipificados.

Human papillomavirus (HPV) is the main cause of cervical cancer. Thus, HPV detection and typing becomes important in order to know the frequency of genotypes present in the region. In this paper we studied 44 biopsies of cervical adenocarcinoma. For HPV detection nested polymerase chain reaction (PCR) was used to amplify the L1 gene. For viral typing restriction enzymes (Rsa I, Dde I, Pst I) and DNA sequencing were used. Viral DNA was detected by nested L1 PCR in 100 percent of biopsies; 38/44 cases could be typed: 81.6 percent HPV16; 13.2 percent HPV 18; 2.6 percent VPH 33 and 2.6 percent HPV 18/33. Conclusions: The technique was successful in identifying the virus type in 86 percent of biopsies. There was a strong association ACC-HPV, especially with the viral type 16, detected in 81.6 percent of established cases.

Detección y tipificación de virus papiloma humano en adenocarcinoma de cuello uterino mediante reverse line blot, Región de La Araucanía, Chile / Detection and genotyping of human papillomavirus in biopsies of uterine cervical adenocarcinoma

Background: The genotyping of Human Papillomavirus (HPV) will improve knowledge about the local epidemiological association of this virus with adenocarcinoma. Aim: To determine the frequency of HPV genotypes in biopsies of women with uterine cervical adenocarcinoma in a geographic region of Chile. Materials and Methods: Forty-one cervical biopsies with a pathological diagnosis of adenocarcinoma, corresponding to all women diagnosed with this cancer between 2002 and 2004, were analyzed. Viral gene Ll was amplified by PCRfor viral detection. HPV genotyping was carried out by a Reverse Line Blot technique. Results: Seventy one percent of biopsies were positive for HPV. The most common genotypes found were HPV 16 (61 percent), followed by HPV 18 (19.5 percent). Eighty seven percent of biopsies had a single HPV infection. Three patients had a multiple HPV infection. All of the latter were infected by HPV 16, associated with other three viral genotypes (45, 52 and 66). No low-risk HPV genotypes were found. Conclusions: In this sample of biopsies, there was a high prevelence of HPV 16 and a low prevalence of HPV 18, which historically has been related to adenocarcinoma. The genotypes found correspond to those described in South America.

Investigation of the Bovine Leukemia Virus Proviral DNA in Human Leukemias and Lung cancers in Korea

The bovine leukemia virus (BLV) is the causative agent of enzootic bovine leucosis. This study investigated the presence of the BLV in leukemia (179 acute lymphoblastic leukemia, 292 acute myeloid leukemia and 46 chronic myelogenous leukemia cases) and 162 lung cancer patients (139 adenocarcinoma, 23 squamous cell carcinoma) to determine if the BLV is a causative organism of leukemia and lung cancer in Koreans. A BLV infection was confirmed in human cells by PCR using a BLV-8 primer combination. All 517 cases of human leukemia and 162 lung cancer were negative for a PCR of the BLV proviral DNA. In conclusion, although meat has been imported from BLV endemic areas, the BLV infection does not appear to be the cause of human leukemia or lung cancer in Koreans. These results can be used as a control for further studies on the BLV in Koreans.

Epstein-Barr virus infection and gastric carcinoma in São Paulo State, Brazil

Epstein-Barr virus (EBV) is a ubiquitous herpesvirus, and most people have serological evidence of previous viral infection at adult age. EBV is associated with infectious mononucleosis and human cancers, including some lymphomas and gastric carcinomas. Although EBV was first reported in lymphoepithelioma-like gastric carcinoma, the virus was also found in conventional adenocarcinomas. In the present study, 53 gastric carcinomas diagnosed in São Paulo State, Brazil, were evaluated for EBV infection by non-isotopic in situ hybridization with a biotinylated probe (Biotin-AGACACCGTCCTCACCACCC GGGACTTGTA) directed to the viral transcript EBER-I, which is actively expressed in EBV latently infected cells. EBV infection was found in 6 of 53 (11.32 percent) gastric carcinomas, mostly from male patients (66.7 percent), with a mean age of 59 years old. Most EBV-positive tumors were in gastric antrum. Two EBV-positive tumors (33.3 percent) were conventional adenocarcinomas, whereas four (66.7 percent) were classified as lymphoepithelioma-like carcinomas. EBV infection in gastric carcinomas was reported elsewhere in frequencies that range from 5.6 percent (Korea) up to 18 percent (Germany). In Brazil, a previous work found EBV infection in 4 of 80 (5 percent) gastric carcinomas, whereas another study found 4.7 and 11.2 percent of EBV-positive gastric carcinomas of Brazilians of Japanese origin or not, respectively. In the present study, the frequency of EBV-positive gastric carcinomas is similar to that reported in other series, and the clinicopathologic characteristics of these EBV-positive tumors are in agreement with the data in the literature.

Telomerase activity in thymomas and mammary gland adenocarcinomas induced by polyoma virus in AKR mice

Telomerase is an enzyme that stabilizes telomere lenght in transformed cells and tumors. Its role in tumor development is far from clear. In this paper, a new experimental model to study telomerase activity during tumorigenesis is presented. After infection with Polyoma virus, AKR mice developed thymomas and mammary gland adenocarcinomas. Polyoma antigens were observed by the peroxidase-antiperoxidase technique on tissue sections, and by Western blot on tumor extracts. The TRAP assay was performed to detect telomerase activity. It was not present in normal mammary gland, but it was positive in mammary gland adenocarcinomas. A different pattern was seen in thymic tissues: normal thymus had higher telomerase activity than thymomas. The incubation of thymoma extracts with normal thymus extracts decreased telomerase activity in the latter. These results demonstrate two different patterns of telomerase activity in tumors induced by Polyoma virus, and suggest the presence of telomerase inhibitory factors in thymomas.

Infección por Helicobacter pylori y el riesgo de carcinoma gástrico: presentación de un caso / Helicobacter pylori infection and the risk of gastric carcinoma: report of a case

The authors present the clinical history of a patient with gastritis of the antrum who subsequently had early gastric cancer of the antrum. The authors review the literature on the infection by Helicobacter pylori as a risk factor for gastric carcinoma. The infection produces chronic gastritis, gastric ulcer, duodenal ulcer and is a probable risk factor for gastric carcinoma