Connexin 26 expression correlates with less aggressive phenotype of intestinal type-gastric carcinomas

Connexin 26 (Cx26), one of the gap junction-forming family members, is more controversial than other members, as a tumor suppressor. Here, we assessed Cx26 expression in gastric carcinoma, which has not been investigated before, and its clinical significance including survival analyses. Cx26 expression was assessed in 205 tissue samples from gastric carcinoma by immunohistochemistry. Of 205 gastric carcinoma cases, 79 (38.5%) were positive for Cx26 with mainly cytoplasmic localization compared to sporadic membranous staining in normal epithelium, and the expression levels were confirmed by Western blotting and real-time PCR. Negative associations were revealed between Cx26 expression and most clinicopathologic features (all P<0.05). Notably, high Cx26 expression was associated with histological intestinal-type (P=0.017) and early stage of gastric carcinoma. The multivariate regression analysis revealed that positive Cx26 expression was an independent prognostic predictor of intestinal-type GC (P=0.023, HR=2.019). Our findings suggest that aberrant expression of Cx26 in cytoplasm plays a tumor-suppressor role in gastric carcinoma and is an independent biomarker for favorable prognosis in intestinal-type gastric carcinoma.