Poirah Indrajit, Chakraborty Soumyadeep, Padhan Pratyush Kumar, Mishra Ashish Kumar, Chakraborty Debashish, Dixit Pragyesh, Samal Supriya, Rout Niranjan, Singh Shivaram Prasad, Nath Gautam, Smoot Duane T, Ashktorab Hassan, Bhattacharyya Asima
School of Biological Sciences, National Institute of Science Education and Research (NISER) Bhubaneswar, An OCC of Homi Bhabha National Institute, Odisha, India.
Dioscuri Centre for Physics and Chemistry of Bacteria, Institute of Physical Chemistry-Polish Academy of Sciences, Warsaw, Poland.
Cancer Med. 2025 May;14(9):e70860. doi: 10.1002/cam4.70860.
The gastric epithelium experiences intermittent hypoxia due to various physiological and pathological conditions. However, the impact of hypoxia and hypoxia-reoxygenation of gastric epithelial cells (GECs) on Helicobacter pylori-mediated gastric cancer (GC) has never been investigated. Carcinoembryonic antigen-related cell adhesion molecules (CEACAMs) facilitate H. pylori adhesion onto GECs. We evaluated the effect of hypoxia and hypoxia-reoxygenation on CEACAM6-mediated H. pylori binding, infection, reactive oxygen species (ROS) generation, and GEC proliferation.
Hypoxia-inducible factor 1 (HIF1α) and CEACAM6 levels were assessed in various GECs. ROS were measured using 2',7'-dichlorofluorescin diacetate (DCFDA). Bioinformatics analyses were performed to identify the most prominent stomach adenocarcinoma (STAD)-associated NADPH oxidase (NOX) followed by validation by overexpression/suppression studies and western blotting. GC biopsies were examined by immunofluorescence microscopy. Hypoxia-exposed, reoxygenated, or control cells were compared for ROS generation and H. pylori infection. MTT assay determined cell proliferation.
Hypoxia and HIF1 mediated upregulation of CEACAM6 in GECs. CEACAM6 significantly promoted ROS generation by inducing NOX4 in hypoxic GECs. HIF1α, CEACAM6, and NOX4 upregulation was detected in gastritis and GC tissues. H. pylori infection significantly increased in hypoxia-exposed GECs as compared to normoxic GECs. Infection of hypoxia-reoxygenated GECs also resulted in significantly increased CEACAM6 and NOX4-mediated ROS generation compared to normoxic GECs. In addition, adhesion of H. pylori, cytotoxin-associated gene A (CagA) translocation, and GEC proliferation were significantly enhanced in hypoxia-reoxygenated GECs. Collectively, this study established that hypoxia and hypoxia-reoxygenation of GECs facilitate H. pylori infection and infection-mediated GEC proliferation.
由于各种生理和病理状况，胃上皮会经历间歇性缺氧。然而，胃上皮细胞（GECs）的缺氧及缺氧复氧对幽门螺杆菌介导的胃癌（GC）的影响从未被研究过。癌胚抗原相关细胞黏附分子（CEACAMs）促进幽门螺杆菌黏附于GECs。我们评估了缺氧和缺氧复氧对CEACAM6介导的幽门螺杆菌结合、感染、活性氧（ROS）生成及GEC增殖的影响。
评估了各种GECs中缺氧诱导因子1（HIF1α）和CEACAM6的水平。使用二氯荧光素二乙酸酯（DCFDA）测量ROS。进行生物信息学分析以鉴定最显著的胃腺癌（STAD）相关的烟酰胺腺嘌呤二核苷酸磷酸氧化酶（NOX），随后通过过表达/抑制研究及蛋白质免疫印迹法进行验证。通过免疫荧光显微镜检查GC活检组织。比较缺氧暴露、复氧或对照细胞的ROS生成及幽门螺杆菌感染情况。MTT法测定细胞增殖。
缺氧和HIF1介导GECs中CEACAM6的上调。CEACAM6通过在缺氧GECs中诱导NOX4显著促进ROS生成。在胃炎和GC组织中检测到HIF1α、CEACAM6和NOX4上调。与常氧GECs相比，缺氧暴露的GECs中幽门螺杆菌感染显著增加。与常氧GECs相比，缺氧复氧GECs的感染也导致CEACAM6和NOX4介导的ROS生成显著增加。此外，在缺氧复氧GECs中，幽门螺杆菌的黏附、细胞毒素相关基因A（CagA）易位及GEC增殖显著增强。总体而言，本研究证实GECs的缺氧和缺氧复氧促进幽门螺杆菌感染及感染介导的GEC增殖。
