CpG island methylator phenotype and Helicobacterpylori infection associated with gastric cancer

• Published in: 世界胃肠病学杂志：英文版 2012, Vol.18 (36), p.5129-5134
• Main Author: Ji-Bin Liu Xu-Ming Wu Jin Cai Jin-Ye Zhang Jin-Lin Zhang Shu-Hui Zhou Min-Xin Shi Fu-Lin Qiang
• Format: Article
• Language: English
• Subjects: CpG岛; 基因甲基化; 幽门螺旋杆菌; 幽门螺杆菌; 感染; 胃癌; 血清样品; 表型
• ISSN: 1007-9327; 2219-2840

AIM： To investigate the association between the CpG island methylator phenotype （CIMP） and serum Helico- bacter pylori （H. pylori） levels for clinical prediction of gastric cancer （GC） progression. METHODS： We analyzed the serum ClMP status of 75 patients with GC using a methylation marker panel and a methylation-specific polymerase chain reaction. Serum samples from 40 healthy persons were examined at the same time. The genes examined were APC, WIF-1, RUNX-3, DLC-1, SFRP-1, DKK and E-cad. H. pylori infec- tion in serum was assayed with an anti-H, pylori immu- noglobulin G antibody test and a rapid urease test. RESULTS： The frequencies of high-level methylation in GC tissues for the seven genes were： 48% for APC, 57.33% for WIF-1, 56% for RUNX-3, 50.67% for DLC-1, 52% for SFRP-1, 54.67% for DKK, and 48% for E-cad.The frequencies in GC serum were 30.67% for APC, 34.67% for WIF-1, 37.33% for RUNX-3, 29.33% for DLC-1, 33.33% for SFRP-1, 32% for DKK, and 26.67% for E-cad. CIMP＋ （defined as ≥ 3 methylated genes） was associated with 47 （62.67%） GC tissue samples and 44 （58.67%） GC serum samples. CIMP＋ was not associated with non-neoplastic mucosal tissues or the serum of healthy persons. Of the 75 GC cases, 51 （68%） were H. pylori＋, and 24 （32%） were H. pylori-. Of the 51 H. pylori＋ cases, 36 were CIMP＋ and 15 were CIMP-. In contrast, for the 24 H. pylori- cases, 11 were CIMP＋, and 13 were CIMP-. The difference was signifi- cant between the H. pylori＋ and H. pylori- groups χ2 = 4.27, P 〈 0.05）. Of the 51 H. pylori＋ GC patients, 34 were CIMP＋ and 17 were CIMP-, while among the 24 H. pylori- GC cases, 10 were CIMP＋ and 14 were CIMP-. The difference was significant between the H. pylori＋ and H. pylori- groups （χ2 = 4.21, P 〈 0.05）. A 2-year follow-up showed significant difference in the rates of metastasis and recurrence between H. pylori＋/CIMP＋ cases and the H. pylori＋/CIMP- cases or CIMP- cases associated with H. pylori assayed in serum （P 〈 0.05）. However, there were no significant differences in sur- vival rates between the two groups. CONCLUSION： H. pylori＋/CIMP＋ cases are associ- ated with higher rates of metastasis and recurrence thanH, pylori＋/CIMP- cases. Serum may be useful for examining CIMP status.