Diverse Characteristics of the cagA Gene of Helicobacter pylori Strains Collected from Patients from Southern Vietnam with Gastric Cancer and Peptic Ulcer
Diverse Characteristics of the cagA Gene of Helicobacter pylori Strains Collected from Patients from Southern Vietnam with Gastric Cancer and Peptic Ulcer
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DOI：
10.1128/jcm.00504-09
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发表时间：
2009-12-01
影响因子：
9.4
通讯作者：
Azuma, Takeshi
中科院分区：
文献类型：
--
作者：
Bui Xuan Truong;Vo Thi Chi Mai;Azuma, Takeshi
胃十二指肠疾病的发病机制与幽门螺杆菌菌株的多样性有关。CagA阳性菌株比CagA阴性菌株更容易导致胃癌。H.基于磷酸化位点对应的羧基末端的EPIYA（Glu-Pro-Ile-Tyr-Ala）基序，H. pylori CagA分为东亚CagA和西方CagA。前一种类型在东亚流行，与胃癌关系更密切。本研究利用22 H. pylori菌株在越南南部胃癌和消化性溃疡患者中进行比较，以比较越南菌株之间以及它们与东亚其他菌株之间的遗传同源性。根据来自世界各地的54篇参考文献，基于22个越南株的全氨基酸序列构建了系统发育树。cagA基因在所有越南人血吸虫中均被发现。pylori菌株。22株中有21株（95.5%）属于东亚型，其羧基端氨基酸序列特征与东亚地区的其他菌株相似。根据东亚CagA和越南流行病学癌病变的证据，H。幽门螺杆菌感染的越南人可以被归类为胃癌的高危人群，但环境和毒力因素之间的相互作用还有待进一步研究。最后，系统发育数据支持在Western CagA型中存在日本亚型。
The pathogenesis of gastroduodenal diseases is related to the diversity of Helicobacter pylori strains. CagA-positive strains are more likely to cause gastric cancer than CagA-negative strains. Based on EPIYA (Glu-Pro-Ile-Tyr-Ala) motifs at the carboxyl terminus corresponding to phosphorylation sites, H. pylori CagA is divided into East Asian CagA and Western CagA. The former type prevails in East Asia and is more closely associated with gastric cancer. The present study used full sequences of the cagA gene and CagA protein of 22 H. pylori strains in gastric cancer and peptic ulcer patients from Southern Vietnam to make a comparison of genetic homology among Vietnamese strains and between them and other strains in East Asia. A phylogenetic tree was constructed based on full amino acid sequences of 22 Vietnamese strains in accordance with 54 references from around the world. The cagA gene was found in all Vietnamese H. pylori strains. Twenty-one of 22 (95.5%) strains belonged to the East Asian type and had similar characteristics of amino acid sequence at the carboxyl terminus to other strains from the East Asian region. From evidence of East Asian CagA and epidemiologic cancerous lesions in Vietnam, H. pylori-infected Vietnamese can be classified into a high-risk group for gastric cancer, but further studies on the interaction among environmental and virulence factors should be done. Finally, phylogenetic data support that there is a Japanese subtype in the Western CagA type.