Publications (2)1.59 Total impact
Article: Amino acid polymorphisms flanking the EPIYA-A motif of Helicobacter pylori CagA C-terminal region is associated with gastric cancer in East China.[show abstract] [hide abstract]
ABSTRACT: OBJECTIVE: Helicobacter pylori (H. pylori) is a major pathogen that causes chronic gastritis, peptic ulcers, gastric cancer, and mucosa-associated lymphoid tissue lymphoma. The cagA gene of H. pylori is one of the most-studied virulence factors; diversity in its 3' variable region is related to the severity of associated diseases. METHODS: Gastric mucosal specimens from 170 East China patients were collected, and the genomic DNA of the H. pylori strains was extracted directly from biopsy specimens. Polymerase chain reaction was applied to amplify the cagA gene, and diversity in its 3' variable region was assessed by the use of direct sequencing. RESULTS: A total of 154 (90.6%) H. pylori isolates were cagA-positive, but the presence of the gene alone was not associated with the type of the patients' gastroduodenal diseases. A total of 151 (88.8%) strains had the East Asian type EPIYA-D sequence, most of which were of the ABD subtype. Three isolates from patients with chronic gastritis possessed the EPIYA-C segment. The sequences flanking the EPIYA motifs contained polymorphisms at seven residues, among which amino acid positions 878 and 879 had a statistically significant association with gastric cancer (P = 0.021). An amino acid change from glycine to aspartic acid at residue 968, which was present only in patients with gastric cancer (4/20) (P<0.001). CONCLUSION: The majority of H. pylori strains present in East China are of the CagA-ABD subtype. Polymorphisms at amino acids 878 and 879 flanking the EPIYA-A motif are statistically associated with gastric cancer.Journal of Digestive Diseases 03/2013; · 1.59 Impact Factor
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ABSTRACT: To screen for potential mutations of LKB1 gene in Chinese familial Peutz-Jeghers syndrome (PJS) patients and analyze their clinical manifestations. Eleven PJS families were collected and genomic DNA of peripheral blood was extracted. Typically mucosal pigmentation and hamartomatous polyps were present in all 11 probands. Mutation screening of the probands were carried out by PCR and direct sequencing. Two hundred and fifty healthy adults were enrolled as normal controls, for whom genomic DNA of peripheral blood was also extracted. PCR-denaturing high performance liquid chromatography was carried out to verify the mutation identified in the patients. Nine germline mutations were identified in eight PJS patients, which included 7 point mutations, 1 deletion and 1 insertion. Among these, 4 were considered to be pathogenic, of which 2 were de novel, 4 were considered to be polymorphism, and 1 was uncertain. LKB1 gene mutations with pathogenic effect are a common cause of familial PJS in Chinese patients. Most mutations are point mutations.Zhonghua yi xue yi chuan xue za zhi = Zhonghua yixue yichuanxue zazhi = Chinese journal of medical genetics 04/2012; 29(2):121-5.