Department of Pathology and Forensic Medicine, Federal University of Ceará, Fortaleza, Ceará, Brazil.
Department of Genetics, Biomedical Center, Federal University of Pernambuco, Recife, Pernambuco, Brazil.
Infect Genet Evol. 2020 Oct;84:104477. doi: 10.1016/j.meegid.2020.104477. Epub 2020 Jul 29.
It is known that Helicobacter pylori is the main cause of peptic ulceration and gastric cancer. However, there is a lack of information on whether H. pylori strains may differ in gastric cancer histological subtypes. This study aimed to investigate different H. pylori strains considering six cag Pathogenicity Island - cagPAI genes (cagA, cagE, cagG, cagM, cagT, and virb11), and vacuolating cytotoxin - vacA alleles, and their relation to gastric cancer histologic subtypes. For this purpose, tumor samples from 285 patients with gastric carcinoma were used. H. pylori infection and genotypes were determined by polymerase chain reaction (PCR). H. pylori was detected in 93.9% of gastric tumors. For comparative analyzes between histopathological subtypes considering H. pylori cagPAI genes the strains were grouped according to the vacA s1/s2 alleles. In the vacAs1 group, the strains cagA(-)cagE(+), cagA(+)cagE(+)cagG(+), cagA(+)cagM(+), or only cagE(+) strains were more frequent in the intestinal subtype (P = .009; P = .024; P = .046, respectively). In contrast, cagM(+)cagG(+)cagA(-) and cagE(-) were associated with diffuse tumors (P = .036), highlighting the presence of cagE in the development of intestinal tumors, and the presence of cagG and absence of cagE in diffuse tumors. Furthermore, WEKA software and Decision Tree (CART) analyses confirmed these findings, in which cagE presence was associated with intestinal tumors, and cagE absence and cagG(+) with diffuse tumors. In conclusion our results showed that vacAs1 (cagG + cagM) strains, mainly cagG positive with cagE absence, were relevant in the studied population for the diffuse outcome, while the presence of cagE was relevant for the intestinal outcome. These findings suggest the relevance of these H. pylori genes as potential markers for gastric cancer histological outcomes.
已知幽门螺杆菌是消化性溃疡和胃癌的主要病因。然而，关于幽门螺杆菌菌株是否在胃癌组织学亚型上存在差异，目前信息还很缺乏。本研究旨在调查不同的幽门螺杆菌菌株，考虑了 6 个细胞毒素相关基因座 - cagPAI 基因（cagA、cagE、cagG、cagM、cagT 和 virb11）和空泡细胞毒素 - vacA 等位基因，及其与胃癌组织学亚型的关系。为此，使用了 285 例胃癌患者的肿瘤样本。通过聚合酶链反应（PCR）检测幽门螺杆菌感染和基因型。在 93.9%的胃肿瘤中检测到幽门螺杆菌。为了在考虑幽门螺杆菌 cagPAI 基因的组织病理学亚型之间进行比较分析，根据 vacA s1/s2 等位基因将菌株进行分组。在 vacAs1 组中，cagA(-)cagE(+)、cagA(+)cagE(+)cagG(+)、cagA(+)cagM(+)或仅 cagE(+)菌株在肠型中更为常见（P =.009；P =.024；P =.046）。相反，cagM(+)cagG(+)cagA(-)和 cagE(-)与弥漫型肿瘤相关（P =.036），突出了 cagE 在肠型肿瘤发生中的存在，以及 cagG 的存在和 cagE 的缺失与弥漫型肿瘤相关。此外，WEKA 软件和决策树（CART）分析证实了这些发现，其中 cagE 的存在与肠型肿瘤相关，而 cagE 的缺失和 cagG(+)与弥漫型肿瘤相关。总之，我们的结果表明，在研究人群中，vacAs1（cagG + cagM）菌株，主要是 cagG 阳性且 cagE 缺失，与弥漫性结果相关，而 cagE 的存在与肠型结果相关。这些发现表明这些幽门螺杆菌基因作为胃癌组织学结果的潜在标志物具有重要意义。
