Abstract: Objective To investigate the expression of calpain small subunit-1（Capn4） and nuclear proliferation marker（Ki-67） in colon cancer and its clinical significance. Methods Immunohistochemical method was used to detect the expression of Capn4 and Ki-67 in 70 cases of colon cancer and 35 cases of adjacent normal tissues. The relationship between the expression of Capn4 and Ki67 and the clinicopathological features of colon cancer was analyzed.
Results The positive expression rates of Capn4 and Ki-67 in colon cancer tissues were 74.3％（52/70） and 84.3％（59/70）， which were significantly higher than 22.9%（8/35） and 17.1%（6/35） of adjacent normal tissues， and the difference was statistically significant（P＜0.05）. The expression of Capn4 and Ki-67 was closely related to the depth of invasion， TNM stage and lymph node metastasis（P＜0.05）， which was not related with age， sex and differentiation degree（P＞0.05）. The expression of Capn4 was positively correlated with Ki-67 in colon cancer tissues（r=0.734， P＜0.05）. Conclusion Capn4 and Ki-67 are highly expressed in colon cancer， and may be related to the occurrence and development of colon cancer.