Expression of CD133 and CD44 proteins in gastric stromal tumors and their clinical significances

Objective To investigate the expression of CD133 and CD44 proteins in gastric stromal tumors (GST) and their clinical significances. Methods The expression of CD44 and CD133 proteins in the GST tissues of 112 patients was detected by immunohistochemical staining. The relation between the expression of CD44 and CD133 proteins and the clinicopathological characters was analyzed. The survival and prognosis of GST were also analyzed. Results Both CD44 and CD133 were expressed on the cell membranes. The expression rates of CD44 and CD133 were 58.04% (65/112) and 42.86% (48/112) separately; the co-expression rate of CD44 and CD133 was 27.68% (31/112). CD44 and CD133 were negative in normal peritumoral tissues. No correlation was found between CD44 and CD133 and the clinicopathological parameters including gender, age and lymphatic vessel invasion (all P > 0.05), but the expression levels of CD44 and CD133 in patients with the mitotic count ≥ 5/50 high-power field, large diameter and vascular invasion were significantly higher (all P 0.05), but the co-expression level of CD44 and CD133 in patients with tumor diameter ≥5 cm was significantly higher than that in patients with tumor diameter < 5 cm (χ2=5.040, P = 0.025). The overall survival rate of the patients with co-expression of CD44 and CD133 was shorter than that in other groups (χ2 = 8.758, P = 0.001). No correlation was found between CD44 and CD133 expression (r = 0.126, P = 0.210). Multivariate analysis with the Cox regression models showed that the tumor diameter ≥5 cm (P = 0.042) and co-expression of CD44 and CD133 (P = 0.003) were significantly associated with poor prognosis. Conclusion CD44 and CD133 as robust cancer stem cell markers in GST might be the prognostic factors. Key words: Gastric stromal tumors; Prognosis; Antigens, CD44; Antigens, CD133