ABSTRACT
@# Objective: To investigate the therapeutic effect of dendritic cell-induced killer cells (DC-CIK) combined with 5-fluorouracil (5-FU) and loaded with CD133+ HT-29 cell lysate or RNA on mice bearing colon cancer HT-29 cell transplanted tumor, and to explore the underlying mechanism. Methods: Colon cancer xenograft model was established in BALB /c nude mice by using human colon cancer HT-29 cells at logarithmic growth phase; Antigen-free DC-CIK, 5-FU+DC-CIK, R+DC-CIK (loaded with total RNA of CD133+ cells), L+DC-CIK (loaded with CD133+ cell lysate), 5-FU and normal saline were respectively injected into transplanted mice, and the treatment efficacies on the growth of transplanted tumor in each group after three treatment cycles were observed, and the tumor growth curve was drawn. The nude mice were sacrificed by cervical dislocation and the tumor volume and body weight were measured. qPCR was used to detect the expression of AKT mRNA in transplanted tumor tissue, and WB was used to detect the expression of phosphorylated AKT protein. Results: After treatment, the body mass of nude mice in R+DC-CIK group, L+DC-CIK group and 5-FU+DC-CIK group increased steadily, while the body mass of nude mice in DC-CIK group and 5-FU group decreased gradually; the tumor growth speed of nude mice in R+DC-CIK group, 5-FU+DC-CIK group and L+DC-CIK group was significantly slower than that of the control group (P<0.05). Compared with 5-FU and DC-CIK alone, the combined treatment with loaded lysate/RNA had more sig nificant effect on mRNA and protein expressions of AKT(P<0.05). Conclusion: The effect of DC-CIKwithdifferentloadingoritscombinationwith5-FUisbetterthanthatofchemotherapy alone. One of the mechanisms is related to the down-regulation ofAKT level.