CagA Protein Regulating the Biological Characteristics of Gastric Cancer through the /SMAD2/SP1 axis.

() is a grade Ι carcinogen of gastric cancer (GC), and its high infection rate seriously affects human health. Cytotoxin-associated gene A (CagA) plays a key role in the carcinogenesis of as one of its main virulence factors. is abnormally expressed in patients with GC, associated with the occurrence and development of cancer. However, little is known about the association between CagA and . (1) Background: This study explored the association and mechanism of CagA and in GC. (2) Methods: The sequence was obtained from the NCBI. After sequence optimization, it was connected to the pcDNA3.1 vector to construct a CagA eukaryotic expression plasmid (pcDNA-). Quantitative real-time polymerase chain reaction (qRT-PCR) was used to investigate the expression of and in GC cells. The function of CagA on GC cells was detected by CCK8, wound healing, and Transwell assays. Similarly, the function of was also studied through the above functional experiments after the overexpression and knockdown models had successfully been constructed. The associations among CagA, , and SMAD2/SP1 were evaluated using RNA immunoprecipitation (RIP) and rescue experiments. (3) Results: The expression of was significantly reduced in GC cells, and the expression of was further reduced after CagA induction. Both overexpressed CagA and knockdown cell models enhanced malignant transformation, whereas overexpressed inhibited malignant transformation in vitro. The function of on GC cells could be influenced by CagA. We also found that the influence of on SMAD2 and SP1 could be regulated by CagA. (4) Conclusions: CagA potentially regulates the biological function of GC cells through the /SMAD2/SP1 axis. could be a therapeutic target for GC related to CagA.