Association of gankyrin protein expression in human colorectal cancer with postoperative prognosis

Abstract

To investigate the association of gankyrin protein expression in colorectal cancer (CRC) with its prognosis. Clinical data and resection samples of 100 colorectal cancer patients identified by pathology undergoing resection in our department from June 2008 to June 2009 were collected. The gankyrin expression in CRC tissues and matched adjacent noncancerous tissues collected during the operation of 100 CRC cases was detected by immunohistochemical staining and Western blotting. The associations of gankyrin expression level with overall survival, clinicopathologic features were analyzed by Chi square test, Cox regression analysis, Kaplan-Meier analysis and log rank test. Immunohistochemical staining showed that the positive brown granules were mainly distributed in the cytoplasm, and nuclear immunostaining was observed in tissue samples of 29 cases, of whom 16 cases had distal metastasis [55.2% (16/29)]. The positive rate of gankyrin and the relative gray value of Western blotting in CRC tissues were 67% (67/100) and 0.69±0.23, respectively, which were significantly higher than those of 2 cm adjacent noncancerous tissues [6% (6/100) and 0.31±0.16] and 10 cm adjacent noncancerous tissues [1%(1/100) and 0.16±0.11] (all P<0.001). Patients with positive expression of gankyrin had worse survival than those with negative ones (41.8% vs. 72.7%, P=0.008). The gankyrin expression was associated to lymph node metastasis (P=0.005), tumor stage (P=0.001) and distal metastasis (P=0.002). Cox regression analysis showed that distal metastasis (P=0.004) and high expression of gankyrin (P=0.038) were independent risk factors for poor prognosis of patients with CRC. Up-regulated expression of gankyrin is related to invasion and metastasis of human CRC, and gankyrin may be valuable in predicting prognosis.