Polimorfismo genético relacionado al metabolismo de la aflatoxina y el riesgo de cáncer vesicular en mujeres chilenas / Aflatoxin metabolism-related genetic polymorphisms and the risk of gallbladder cancer in Chilean women

Background/aim: High consumption of red chili pepper has been shown to be a risk factor for gallbladder cancer (GBC) in Chilean women with gallstones (GS). GS are the main cause of GBC, but not all patients with gallstones develop GBC. Since red chili pepper is a widely consumed spice among the Chilean population, the development of GBC in Chilean women cannot be completely explained by the presence of GS and red chili pepper consumption alone. Genetic factors in addition to these and other environmental factors may also be associated with an increased risk of GBC. We aimed to study whether genetic polymorphisms involved in aflatoxin metabolism are associated with the risk of GBC in Chilean women, because we detected aflatoxins B1 and B2 in red chili pepper purchased in Santiago, Chile. Methods: We conducted a hospital-based case-control study whose subjects were 57 patients with GBC, 119 patients with GS, and 70 controls. DNA was extracted from subjects’ blood or paraffin block samples using standard commercial kits. The statuses of the genetic polymorphisms of cytochrome P450 (CYP) 1A2 rs762551 and CYP3A4 rs2740574 were assayed using the TaqMan® SNP Genotyping Assay or the Custom TaqMan® SNP Genotyping Assay, respectively. Results: In the assay for the CYP1A2 polymorphism, of the 57 GBC patients, 23 (40.3 percent) had at least one minor allele (A/C or C/C). However, there were no significant differences in the genotypic or allelic frequencies among the three subject groups. In the assay for the CYP3A4 polymorphism, the minor G/G genotype was not detected in the three groups, and there were no significant differences in the genotypic or allelic frequencies among the three groups. Conclusion: These genetic polymorphisms were not related to the risk of GBC in Chilean women. Further studies including a greater number of controls and cases are needed to confirm this preliminary exploratory result.

Introducción/objetivo: El alto consumo de ají rojo ha demostrado ser un factor de riesgo de cáncer vesicular (CV) en mujeres chilenas con cálculos vesiculares. Los cálculos vesiculares son la causa principal de CV, no obstante, no todos los pacientes con cálculos vesiculares desarrollan CV. Debido a que el ají rojo es una especia ampliamente consumida entre la población chilena, el desarrollo de CV en las mujeres chilenas no puede ser explicado en su totalidad sólo por la presencia de cálculos vesiculares y consumo de ají rojo. Factores genéticos además de éstos y otros factores ambientales, también podrían estar relacionados con un aumento del riesgo de CV. Nuestro objetivo es estudiar si los polimorfismos genéticos involucrados en el metabolismo de la aflatoxina están relacionados con el riesgo de CV en mujeres chilenas, porque detectamos aflatoxinas B1 y B2 en ajíes rojos comprados en Santiago de Chile. Métodos: El estudio caso control, incluyó 57 pacientes con CV, 119 pacientes con cálculos vesiculares, y 70 controles. Se extrajo ADN de la sangre de los sujetos o de bloques de parafina, usando kits comerciales estándar. El estado de los polimorfismos genéticos del citocromo P450 (CYP) 1A2 rs762551 y CYP3A4 rs2740574 fueron estudiados usando el ensayo de genotipo SNP TaqMan® o el ensayo de genotipo SNP Custom TaqMan®, respectivamente. Resultados: En el ensayo para el polimorfismo CYP1A2, de los 57 pacientes con CV, 23 (40,3 por ciento) tuvieron al menos un alelo menor (A/C o C/C). No obstante, no hubo diferencias significativas en las frecuencias genotípicas o alélicas entre los tres grupos. En el ensayo para el polimorfismo CYP3A4, el genotipo menor G/G no fue detectado en los tres grupos, y no hubo diferencias significativas en las frecuencias genotípicas o alélicas entre los tres grupos. Conclusión: Estos polimorfismos genéticos no estaban relacionados con el riesgo de CV en mujeres chilenas...

Effect of genetic predisposition on the risk of gallbladder cancer in Hungary.

A CYP1A1 polymorphism has been associated with an increased risk for gallbladder cancer (GBC) in Japanese women. However, genetic risk factors for GBC in Hungary, where the population has a relatively high GBC incidence, has not been well studied. We therefore tested associations between CYP1A1 T3801C, CYP1A1 Ile462Val, GSTM1deletion, and TP53 Arg72Pro and GBC in Hungary. Genomic DNA was extracted from peripheral blood of 100 controls (52 men and 48 women) and from the tissue embedded in paraffin of 43 cases (6 men and 37 women). The case-control analysis was limited to females due to a small number of males. Of 37 female cases, 21 (56.8%) were diagnosed as adenocarcinoma, and the remaining 16 (43.2%) were classified as non-adenocarcinoma. The odds ratios (ORs) for the Ile/Val genotype and the Val allele were 8.9 (95% CI: 2.9-27.4) and 4.4 (95% CI: 1.7-11.1), respectively. The occurrence of the combined variant genotypes of CYP1A1 Ile462Val and GSTM1 (37.8% vs. 8.3%) or CYP1A1 Ile462Val and TP53 Arg72Pro (24.3% vs. 0%) was significantly higher in the cases than in the controls. The Ile/Val genotype was significantly associated with an increased risk of adenocarcinoma (OR 9.2; 95% CI: 2.6-32.6) and non-adenocarcinoma (OR 8.4; 95% CI: 2.2-32.4). Additionally, the Arg/Pro genotype increased risk of non-adenocarcinoma (OR 3.8; 95% CI: 1.2-12.8). The Val allele may contribute to the development of GBC not only in Japanese but also in Hungarian women. Our results provide a rationale for further studies of genetic variation on the risk of GBC in Hungary.

Factors related to starting and continuing smoking among senior high school boys in Fukuoka, Japan.

The purpose of this study was to identify factors that influence starting and quitting smoking among Japanese male adolescents aged 15-18. Two thousand and twelve senior high school boys in Fukuoka City, Japan, answered unsigned self-administrated anonymous questionnaires in July 2001. Odds ratios (ORs) and their 95 % confidence intervals (CIs) were computed to assess the strength of associations between students' smoking status and alcohol consumption habits. Additionally, the link between a students' smoking status and parental influence (parental smoking) was also assessed. Approximately 90% of the students, both current and ex-smokers, had ever smoked prior to senior high school while 77% of the students (smokers and non-smokers) had the experience of drinking alcohol prior to admission to senior high school. After adjustment for school year (i.e., freshman, sophomore, junior, senior), academic education level, after-school club activities, time of first drinking experience and the frequency of drinking, there was a significant increased risk to become a smoker when one parent was a smoker (OR = 1.67, 95% CI = 1.18-2.37) or when both parents were smokers (OR = 2.94, 95% CI = 1.66-5.18) compared to both parents being non-smokers. The consumption of alcohol prior to entering senior high school was significantly associated with more than 2.5-fold greater risk for the onset of smoking when compared to the risk of becoming a smoker when alcohol consumption started after entering senior high school. An increased frequency of drinking was also associated with starting smoking (OR =14.00, 95% CI = 8.08-24.26; 2-3 times/week vs. never). Similarly, an increase in drinking frequency resulted in less likelihood of smoking cessation. For instance, the data showed that, the subjects were 1/3 less likely to quit smoking. Paternal smoking had a significant impact on whether or not a child would quit smoking (OR = 0.55, 95% CI = 0.38-0.81) as compared to a child that had paternal and maternal non-smokers. This study suggested that drinking habits started earlier than smoking habits among adolescents. Many students had already experienced drinking before admission to senior high school, while the experience of smoking mostly typically started after admission to high school. These data show the urgency of developing anti-smoking educational programs that could be developed and introduced prior to admission to high school.

The experiences of smoking in school children up to and including high school ages and the current status of smoking habits; a survey of male high school students in Japan.

OBJECTIVES: The burden of tobacco-induced cancer is so heavy that every country should give the highest priority to tobacco control in its fight against cancer. The purpose of the present study was to investigate the actual conditions of tobacco smoking among boys in Japan. METHODS: A self-administered questionnaire survey. Two thousand and fourteen high school boys in Fukuoka City, Japan, answered unsigned self-administered anonymous questionnaires about tobacco smoking. RESULTS: Among 2014 students, 10.9% were current smokers. The rates of current smokers increased with the school age: 6.3% in the first grade; 11.3% in the second grade; and 15.5% in the third grade (P(trend)<0.01). A total of 35.1% of students had the experience of smoking and 30% experienced smoking before entering high school. Of the students with smoking experience, 28.6% answered that they started smoking because their friends had offered them cigarettes and 52.5% of current smokers bought cigarettes from vending machines. CONCLUSIONS: Health education for anti-smoking in all primary and secondary schools as well as restriction of cigarette vending machines should be strongly recommended.