Claudin 9 Antibody - #DF9396

Figure 2. Identification of the core gene CLDN9 and analysis of its expression in various GC tissues. (A) Relationship between the error rate and number of classification trees. (B) Seven genes were selected based on error rate and number of classification trees, namely CLDN9, GPC3, NT5E, CXCR4, PLOD2, EXT2, and STC1. (C) Relationship between survival time (days) and the risk score of the TCGA-STAD cohort and the mRNA expression heatmap of the seven genes. (D and E) Kaplan-Meier OS analysis of patients with GC in the low- and high-risk groups from the training (TCGA-STAD, n = 375) (D) and validation cohorts (GSE13861 and GSE28541, n = 100) (E). (F-H) ROC curves for the time dependence of OS in the training (TCGA-STAD) (F) and validation (GSE13861 and GSE28541) datasets (F). AUC was evaluated at 1, 3, and 5 years (P < 0.001). (H) Univariate and multivariate Cox analysis was used to determine whether the seven glycolysis-associated genes are an independent prognostic factor for survival in the TCGA dataset. (I) Kaplan-Meier OS analysis of patients with GC in the low and high CLDN9 expression groups in the TCGA dataset (n = 375; P = 0.00037). (J) Boxplot of CLDN9 mRNA levels in noncancerous (n = 34) and GC tissues (n = 415) in the TCGA dataset (P < 0.0001). (K) The mRNA expression of CLDN9 was verified in GC cell lines (HGC-27, AGS, and MKN-45) and human gastric epithelial cells (GES-1) via qRT-PCR. (L) CLDN9 protein levels across different GC cell lines were measured using WB. β-actin was used as a loading control. (M) Representative IHC images of CLDN9 protein expression levels in primary GC, metastatic GC, and paired adjacent normal gastric mucosa. Scale bar = 20 μm. The data are presented as the mean ± SD. *P < 0.05, **P < 0.01,***P < 0.001. AUC: Area under the curve; CLDN9: Claudin-9; CXCR4: C-X-C motif chemokine receptor 4; EXT2: Exostosin glycosyltransferase 2; GC: Gastric cancer; GPC3: Glypican 3; IHC: Immunohistochemistry; ns: Nonsignificant; NT5E: Ecto-5′-nucleotidase; OS: Overall survival; PLOD2: Procollagen-lysine 2-oxoglutarate 5-dioxygenase 2; qRT-PCR: Quantitative real-time polymerase chain reaction; ROC: Receiver operating characteristic curve; SD: Standard deviation; STAD: Stomach adenocarcinoma; STC1: stanniocalcin1; TCGA: The Cancer Genome Atlas; WB: Western blotting.