Table 1.
Antibodies used for immunohistochemical staining.
Table 2.
Overview of clinicopathological features and immunohistochemical staining results.
Fig 1.
Representative immunohistochemical features of seven protein markers including proteins related to leptin signaling pathway (A-G) and in situ hybridization of Epstein-Barr virus encoded small RNAs (H).
(A) Leptin shows cytoplasmic expression in cancer cells (x 400). (B) Leptin-receptor exhibits membranous staining in cancer cells (x 200). (C) pSTAT3 shows nuclear staining in cancer cells (x 400). (D) ERK has nuclear positivity in cancer cells (x 400). (E) pAkt shows cytoplasmic or nuclear staining in cancer cells (x 200). (F) mTOR has cytoplasmic positivity in cancer cells (x 200). (G) HIF-1 alpha has cytoplasmic or nuclear staining in cancer cells (x 400). (H) Most of the cancer cells show blue colored nuclear staining on in situ hybridization for Epstein-Barr virus (x 400).
Table 3.
Comparison of immunohistochemical features between EBV-positive gastric carcinomas and EBV-negative gastric carcinomas.
Fig 2.
Kaplan-Meier survival curves in each group of gastric carcinomas according to leptin-receptor expression status (A-D).
(A) Advanced TNM stage was associated with poor survival of patients in all cases of gastric carcinoma (n = 343) (P < 0.001). (B) Leptin-receptor positivity was related with unfavorable survival outcome in the advanced gastric carcinoma subgroup (n = 207) (P = 0.015). (C) Leptin-receptor positivity was correlated with poor survival rate in the diffuse-type gastric carcinoma subgroup (n = 139) (P = 0.007). (D) Leptin-receptor positivity was compatible with lower survival rate in patients with lymph node metastasis (n = 160) (P = 0.023).
Fig 3.
Effect of leptin-receptor inhibition in gastric carcinoma cells.
Leptin-receptor in total cell lysate was inhibited by siRNA against leptin-receptor (50 μM). Cleaved caspase 3 (p11, p17 and p20 subunits) was remarkably increased in gastric carcinoma cell lines transfected with siRNA against leptin-receptor, comparing to each original cell line and each scrambled siRNA-treated cell line. The beta-actin was loading controls. ‘Si scramble’ means cells transfected with scrambled siRNA, and ‘Si Leptin-R,’ cells transfected with siRNA against leptin-receptor.