Clinicopathologic Significance of KIAA1199 Overexpression in Human Gastric Cancer

KIAA1199 is an inner-ear-specific gene which encodes KIAA1199 protein, the function of which is unknown. KIAA1199 might be a novel, positively regulated target of Wnt signaling. The aim of this study was to examine the expression of KIAA1199 in surgical specimens of gastric cancer to evaluate the clinical outcome. The expression of KIAA1199 mRNA was studied by semiquantitative reverse-transcription polymerase chain reaction (RT-PCR), and the expression status was analyzed from the viewpoint of clinical and pathological factors. Univariate and multivariate analyses were performed. In addition, an immunohistochemical study was performed in the selected samples. A significantly higher expression of KIAA1199 messenger RNA (mRNA) was recognized in tumor tissue compared with that of paired normal tissues (P < 0.01). The cases were divided into high- (n = 39) and low-expression (n = 71) groups according to KIAA1199 expression status in the tumor. The overall 5-year survival rate was significantly better in the KIAA1199 low-expression group (61.2%) than in the high-expression group (29.6%) (P < 0.05). Clinicopathological factors such as well and moderately tumor differentiation, positive lymph node metastasis, positive distant metastases, and positive peritoneal dissemination were more frequently observed in the high-expression group than in the low-expression group (P = 0.02, 0.08, 0.01, and 0.03, respectively). KIAA1199 expression was an independent prognostic factor (P = 0.03). KIAA1199 was highly expressed in gastric cancer, and was associated with prognosis and lymph node metastasis in multivariate analyses. Taken together, KIAA1199 may be a novel gene that plays an important role in progression of gastric cancer.