Coexpression of IQ-Domain GTPase-Activating Protein 1 (IQGAP1) and Dishevelled (Dvl) Is Correlated with Poor Prognosis in Non-Small Cell Lung Cancer

BACKGROUND: IQ-domain GTPase-activating protein 1 (IQGAP1) binds to Dishevelled (Dvl) and functions as a modulator of Dvl nuclear localization in Xenopus embryos. However, the relationship between IQGAP1 and Dvl in tumor tissues is unclear. MATERIALS AND METHODS: We used immunohistochemistry to assess the expressions of IQGAP1 and Dvl in a cohort of 111 non-small cell lung cancer (NSCLC) patients. Association of their localization expressions with clinicopathological factors was also analyzed. RESULTS: The positive rate of IQGAP1 in primary tumors was 48.6% (54/111) for its cytoplamic expression, 9.0% (10/111) for nuclear expression and 31.5% (35/111) for membranous expression; the positive rate of Dvl was 65.8% (73/111) for cytoplamic expression, 9.9% (11/111) for nuclear expression and 10.8% (12/111) for membranous expression. Coexpression rate of IQGAP1 and Dvl was 77.8% (42/54) in the cytoplasm, 80.0% (8/10) in the nucleus and 8.6% (3/35) in the membrane. Coexpression of IQGAP1 and Dvl in the cytoplasm and nucleus were significantly correlated (P<0.05), but not in the membrane (P>0.05). The positive expression rates of cyclin D1 and c-myc were significantly higher in the group of IQGAP1 and Dvl coexpression in the nucleus than that in the cytoplasm. Coexpression rate of IQGAP1 and Dvl in the cytoplasm and nucleus was significantly higher in lymph nodal metastases (63.3%, 19/30) than in primary growths (38.3%, 31/81), correlating with poor prognosis. Five-year survival time after resection in the group with their coexpression in the cytoplasm and nucleus was significantly lower than that with no coexpression (44.705±3.355 vs 58.403±2.543 months, p<0.05). CONCLUSIONS: Coexpression of IQGAP1 and Dvl in the cytoplasm and nucleus was correlated with the lymph nodal metastase and poor prognosis of NSCLC, and coexpression in nucleus might play a critical role in the activation of canonical Wnt pathway.