Cytotoxin-associated gene A increases carcinogenicity of <i>helicobacter pylori</i> in colorectal adenoma
Heng Zhang, Yusheng Liao, Hongfeng Zhang, Jie Wu, Dan Zheng, Zhitao Chen
Abstract
Objective: This study aimed to investigate the correlation of Helicobacter pylori (Hp) infection with disease risk and severity of colorectal adenoma, also to explore the association of cytotoxin-associated gene A (CagA) positive (CagA + )- Hp infection with gastrin and ki-67 expressions in colorectal adenoma patients. Methods: There were 1000 colorectal adenoma patients and 1500 controls consecutively enrolled, then Hp infection status was determined by 14 C urea breath test and rapid urease test. Also, serum CagA expression and gastrin expression of colorectal adenoma patients were determined by enzyme-linked immunosorbent assay. Ki-67 expression in adenoma tissue of colorectal adenoma patients was assessed using immunohistochemistry. Results: Hp + rate in colorectal adenoma patients (623 (62.3%)) was more elevated than that in controls (814 (54.3%)). Multivariate logistic regression model analysis disclosed that Hp + was an independent risk factor for colorectal adenoma. Additionally, Hp + was positively associated with tumor size and high-grade intraepithelial neoplasia in colorectal adenoma patients. Also, serum gastrin expression and intratumoral ki-67 expression were higher in Hp + CagA + patients and Hp + CagA − patients compared to Hp − patients, and they were also higher in Hp + CagA + patients compared to Hp + CagA − patients. Conclusion: Hp infection positively associates with higher disease risk and worse disease conditions of colorectal adenoma, and CagA enhances the carcinogenicity of Hp in colorectal adenoma.