Browsing by Author "Koriyama, Chihaya"
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- ItemE-cadherin and beta-catenin expression in Epstein-Barr virus-associated gastric carcinoma and their prognostic significance(W J G PRESS, 2007) Koriyama, Chihaya; Akiba, Suminori; Itoh, Tetsuhiko; Sueyoshi, Kazunobu; Minakami, Yoshie; Corvalan, Alejandro; Yonezawa, Suguru; Eizuru, YoshitoAIM: To examine the role of E-cadherin and betacatenin in carcinogenesis and to assess their prognostic implication in Epstein-Barr virus-associated gastric carcinomas (EBV-GCs).
- ItemHigh frequency of p 16 promoter methylation in non-small cell lung carcinomas from Chile(2007) Guzman, Leda M.; Koriyama, Chihaya; Akiba, Suminori; Eizuru, Yoshito; Castillo, Darwins; Corvalán R., Alejandro; Aguayo González, FranciscoThe inactivation of tumour suppressor genes by aberrant methylation of promoter regions has been described as a frequent event in neoplasia development, including lung cancer. The p16 gene is a tumour suppressor gene involved in the regulation of cell cycle progression that has been reported to be inactivated by promoter methylation in lung carcinomas at variable frequencies around the world in a smoking habit dependent manner. The purpose of this study was to investigate the methylation status of the promoter region of the p16 gene in 74 non-small cell lung carcinomas from Chile. The frequency of p16 gene inactivation by promoter methylation was determined as 79.7% (59/74). When we considered histological type, we observed that p16 promoter methylation was significantly higher in squamous cell carcinomas (30/33, 91%) compared with adenocarcinomas (21/30, 70%) (p=0.029). In addition, no association between p16 promoter methylation and gender, age or smoking habit was found (p=0.202, 0.202 and 0.147 respectively). Our results suggest that p16 promoter hypermethylation is a very frequent event in non-small cell lung carcinomas from Chile and could be smoking habit-independent.
- ItemHuman papillomavirus in esophageal squamous cell carcinoma in Colombia and Chile(W J G PRESS, 2006) Castillo, Andres; Aguayo, Francisco; Koriyama, Chihaya; Torres, Miyerlandi; Carrascal, Edwin; Corvalan, Alejandro; Roblero, Juan P.; Naquira, Cecilia; Palma, Mariana; Backhouse, Claudia; Argandona, Jorge; Itoh, Tetsuhiko; Shuyama, Karem; Eizuru, Yoshito; Akiba, SuminoriAIM: To examine the presence of human papillomavirus (HPV) in esophageal squamous cell carcinoma (ESCC) specimens collected from Colombia and Chile located in the northern and southern ends of the continent, respectively.
- ItemIdentification of The Distinctive Type i/XhoI plus Strain of Epstein-Barr Virus in Gastric Carcinoma in Peru(INT INST ANTICANCER RESEARCH, 2011) Ordonez, Paula; Koriyama, Chihaya; Ding, Shan; Yoshiwara, Elena; Corvalan, Alejandro H.; Takano, Juan; Chirinos, Jesus L.; Watanabe, Jose; Miyagui, Juan; Hidalgo, Heriberto; Chacon, Pedro; Linares, Victor; Eizuru, Yoshito; Akiba, SuminoriAim: To clarify the reason for the low frequency of Epstein-Barr virus-associated gastric carcinoma (EBVaGC) in Peru, despite the high frequency reported in neighboring countries, the distribution of the distinctive EBV (type i/XhoI+) strain in EBVaGC and a healthy population was examined. Materials and Methods: EBV polymorphisms in BamHI W1/I1 and XhoI restriction site of the latent membrane protein 1 gene (LMP1) were examined among 11 EBVaGCs and 172 healthy controls from Peru, and these frequencies were compared with those in a previous study of Chile and Colombia (n=303). Results: The frequency of the distinctive EBV strain in EBVaGCs (55%) was significantly higher than that in controls (7%). Furthermore, the frequency of this EBV type in Peruvian controls was significantly lower than that in controls from Chile and Colombia (27%, p<0.001). Conclusion: The low frequency of the distinctive EBV strain among the Peruvian population might be a reason for the lower incidence of EBVaGC in Peru, as compared with neighboring countries.