To investigate the effect of siRNA silencing cell cycle-related kinase (CCRK) gene on the growth and apoptosis of colon cancer in mice, and to provide a new idea and method for the treatment of colon cancer.

Fifty BALB / C (nu / nu) nude mice were inoculated with human colorectal carcinoma SW480 cells, in which 30 nude mice were successfully established for transplantation tumor model and were randomly divided into three groups, siRNA CCRK transfection of human SW480 colon cancer cell line (experimental group) and normal cultured SW480 cells (blank control group), and carrying irrelevant sequence fragment shRNA slow transfection of virus SW480 cells (negative control group) respectively.The nude mice were sacrificed and the tumor tissues were removed after 42 days.The tumor weight, CCRKmRNA expression, CCRK protein expression and apoptosis rate were compared between the groups.

siRNA transfection group, tumor weight, CCRK mRNA and CCRK protein expression [(0.54±0.15)g, 1.14±0.24, 0.18±0.05] were significantly lower than those of the control group [(1.05±0.14)g, 2.41±0.42, 0.49±0.07] and empty vector of siRNA group [(1.07±0.12)g, 2.39±0.47, 0.47±0.09, F=21.18, 23.47, 90.03; P<0.01]. There were no significant differences between the blank control group and the empty siRNA vector group (q=0.98, 1.07, 1.13; P>0.05). Cells apoptosis rate in siRNA transfection group (21.23±1.12)% was significantly higher than that in normal control group (6.78±0.37)% and transfected with empty vector of siRNA group (7.25±0.32)% (P<0.01); but there was no significant difference between the blank control group and the empty siRNA vector group (q=1.78, P>0.05).

CCRK targeting siRNA expression vector inoculation with colon cancer can significantly reduce the growth of colon cancer and inhibit the expression of CCRK gene and protein in nude mice; CCRK gene silencing by siRNA can promote the colon cancer cells apoptosis; thus , CCRK gene can serve as a new potential molecular target for rectal cancer in gene therapy by siRNA.