@Article{biocell.2025.063296,
AUTHOR = {Jin Liu, Xiu Zhang, Xiao Hu, Gaofeng Yuan, Kai Chen},
TITLE = {CLDN9 Levels Influence the Biological Activities of Cells in Gastric Cancer},
JOURNAL = {BIOCELL},
VOLUME = {49},
YEAR = {2025},
NUMBER = {4},
PAGES = {665--680},
URL = {http://www.techscience.com/biocell/v49n4/60784},
ISSN = {1667-5746},
ABSTRACT = { <b>Objective:</b> This study examines the significance and functions of CLDN9 in gastric cancer (GC), intending to identify novel targets for diagnosis and treatment. <b>Methods:</b> CLDN9 expression in GC tissues and cell lines was investigated in TCGA data, with analysis with Western blotting, qRT-PCR, and immunohistochemical analyses. Correlations between clinicopathological characteristics, progression-free survival (PFS), and overall survival (OS) were assessed with Cox regression. The effect of CLDN9 knockdown/overexpression on tumorigenic functions (proliferation, migration, and invasion) was assessed using CCK-8, colony formation, and Transwell assays. Tumor-bearing assays were performed to verify the impact of CLDN9 knockdown on the <i>in vivo</i> proliferation of GC cells. <b>Results:</b> Analysis of TCGA data, qRT-PCR, Western blotting, and immunohistochemistry indicated significantly elevated levels of CLDN9 in GC tissues and cell lines (<i>p</i> < 0.01). Compared to the group with high CLDN9 expression, PFS and OS were markedly longer in cases with low CLDN9 levels (<i>p</i> < 0.05). Multivariate regression indicated that CLDN9 levels were independently predictive of GC prognosis. CCK-8, Transwell, and colony formation tests showed that CLDN9 overexpression promoted GC cell proliferation, clonogenicity, and migratory/invasive capabilities, but CLDN9 knockdown markedly reduced these features. Experiments involving tumor-bearing models demonstrated that the suppression of CLDN9 inhibited the <i>in vivo</i> growth of GC cells. <b>Conclusion:</b> In conclusion, this study’s findings suggested that CLDN9 might be a valuable therapeutic target or diagnostic biomarker for GC.},
DOI = {10.32604/biocell.2025.063296}
}