Expression and clinical significance of p62 protein in colon cancer

Abstract

Objective To investigate the expression pattern of p62 protein in colon cancer and its clinical significance. Methods Clinical data of 60 patients with sporadic colon cancer were collected, including the gender, age, ethnicity, primary tumor site, tumor size, histological type and degree of differentiation of tumor, tumor invasion depth, lymph node metastasis and TNM stage. The surgical specimens were also collected. The expression of p62 protein in tumor tissues and adjacent normal tissues was detected by immunohistochemistry, real-time reverse transcriptase-polymerase chain reaction(RT-qPCR) and Western blotting, and its correlation with the clinicopathological data were statistically analyzed. Results The expression of p62 mRNA was up-regulated in 60 cases of colon cancer as compared with adjacent tissues (3.179 4±0.817 0 vs. 1.386 6±0.448 2), and the difference was statistically significant (t=14.633, P=0.000). As compared with adjacent tissues, the expression of p62 protein was up-regulated in colon cancer tissues (0.982 5±0.264 6 vs. 0.329 8±0.114 5), and the difference was statistically significant (t=20.593, P=0.000). The expression of p62 in colon cancer tissue had no significant correlation with the patient’s gender, age, ethnicity, primary tumor site, tumor size, histological type and degree of differentiation of tumor, tumor invasion depth, but correlated to lymph node metastasis and TNM stage (χ2=11.250, P=0.001). Conclusion Colon cancer patients with high expression of p62 have higher lymph node metastasis rate and a later disease stage. The abnormal accumulation of p62 may be correlated to the occurrence and development of colon cancer. Key words: p62; Colon cancer; Immunohistochemistry; Real-time reverse transcriptase-polymerase chain reaction; Western blotting