Abstract: ObjectiveTo investigate the expression of highmobility group nucleosomebinding domain 5（HMGN5） and its clinical significance in colorectal cancer tissues. 
MethodsOne hundred and seventysix cases of colorectal cancer tissues and 78 cases of adjacent normal tissues were collected in Meishan Peoples Hospital from April 2005 to October 2010. Immunohistochemistry was used to detect the expression of HMGN5 in the above tissues. The positive expression rates of HMGN5 in colorectal cancer tissues and adjacent normal tissues were compared. The relationship between the positive rates of HMGN5 and the clinicopathological parameters of colorectal cancer（sex， age， tumor location， pathological grade， TNM staging and tumor size） was analyzed. Besides， the relationship between HMGN5 expression and prognosis was analyzed based on followup data. 
ResultsThe immunohistochemical results showed that the positive expression rate of HMGN5 in colorectal cancer tissues was 6875％（121／176）， higher than 2692％（21／78） of adjacent normal tissues， and the difference was statistically significant（P＜005）. The positive expression rate of HMGN5 in colorectal cancer tissues was not related to age， sex， tumor location， pathological grade and tumor size， but related to TNM staging. The positive expression rate of HMGN5 in tissues of Ⅲ and Ⅳ stage was 8105％（77／95）， higher than 5432％（44／81） of Ⅰ and Ⅱ stage， and the difference was statistically significant（P＜005）. The median overall survival of patients with HMGN5 negative expression was 560 months， longer than 370 months of patients with positive expression（P＜005）. 
ConclusionThe elevated expression of HMGN5 in colorectal cancer tissues was associated with poor prognosis and advanced TNM stage. It may be related to the development of colorectal cancer， and it has some value in the diagnosis of colorectal cancer and the evaluation of the disease.

Key words: Colorectal cancer, Highmobility group nucleosomebinding domain 5, Clinical significance, Prognosis