Clinicopathological significance of Nup88 expression in patients with colorectal cancer

The nucleoporin Nup88 is overexpressed in a series of human malignancies, however, its clinicopathological significance has not been studied. Our aims were to analyze Nup88 expression in normal mucosa, primary tumors and metastases from colorectal cancer patients and further to identify relationships of Nup88 expression with clinicopathological and other factors.

Using immunohistochemistry, we investigated Nup88 expression in 198 primary colorectal tumors, 96 normal mucosa samples and 35 lymph node metastases.

The results showed that the intensity of Nup88 expression increased from the normal mucosa to the primary tumors (p < 0.0001) and tended to increase from the primary tumors to the metastases (p = 0.15). Both primary tumors and metastases presented stronger expression in the invasive margin and vascular-invaded areas. Nup88 expression was positively related to distal tumor location (p = 0.01), infiltrative growth pattern (p = 0.04) and higher proliferative activity (p = 0.04) and reversely to the grade of differentiation (p = 0.02) and apoptosis (p = 0.049). Strong expression of Nup88 predicted a worse outcome in the patients with distal tumors during the follow-up period of up to 3 years (p = 0.02).

It seems that overexpression of Nup88 was involved in the tumorigenesis and aggressiveness of colorectal cancers, and Nup88 may be used as a prognostic factor in patients with distal tumors.