Abstract:Objective To investigate the effect of Coiled-coil domain-containing protein 12 (CCDC12) on growth and invasion of colorectal cancer. Methods Immunohistochemistry (IHC) was used to detect expression of CCDC12 in 94 cases of colorectal cancer and associated adjacent healthy tissues. Growth and invasion related proteins including CyclinD1, P21, matrix metallopeptidase 9 (MMP -9), tissue inhibitor of metalloproteinase 1 (TIMP-1) were also determined. Biological characteristics of cancer were recorded and correlated with concentrations of CCDC12, CyclinD1, P21, MMP -9, TIMP -1 proteins. Results Positive expression rates of CCDC12, CyclinD1, MMP-9 and TIMP-1 in colorectal cancer tissues were significantly increased when compared with those in healthy tissues (x2 = 38.480, 30.312, 38.368 and 7.667, respectively)(P < 0.01) while no significant difference was observed in concentration of P21 in the tissues (x2= 0.862,p =0.353). Intimate correlations of CCDC12 with characters of tumor such as differentiation, depth of invasion,lymphatic metastasis, and TNM stages (x2 = 5.130, 5.902, 9.760 and 4.458; p= 0.024, 0.015, 0.002 and 0.035,respectively) were observed. Spearman correlation analysis showed that the expression of CCDC12 was positively correlated with Cyclin D1 and MMP-9 (x2 = 0.302 and 0.365, p= 0.003 and 0.001, respectively) while negative correlation was found between CCDC12 and P21 (x2 = -0.287,p = 0.005). Conclusions CCDC12 is highly expressed in colorectal cancer, which affects Cyclin D1-, P21- and MMP-9-mediated growth and metastasis of colorectal cancer.