Abstract: objective: To investigate the tumor-inhibitory effect and apoptotic pathway of cytokine-induced killer cells (CIK) co-cultured with dendritic cells (DC) loaded breast cancer stem cell antigen on the same tumor-bearing mice. Methods: Separated breast cancer stem cells from a cell line of MCF-7/ADR and then extract freeze-thaw antigen of the stem cell.DC and CIK cells were respectively derived from peripheral blood mononuclear cells (PBMC) of healthy individuals. CIK was co-cultured with DC pulsed or unpulsed by the above antigen lyses.This DC-CIK will injected to tumor-bearing mice which was injected by MCF-7/ADR cell before, and contrast with the common breast cancer antigen pulsed of DC-CIK(SCAP-DC-CIK), without antigen pulsed DC-CIK(AP-DC-CIK), CIK with DC and normal saline (NS).The antitumor effects were evaluated and compared in 5 groups through the tumor size, TUNEL and examining BCL-2, Bax andβ-catenin. Results: The tumor volume of each group was of difference in significance.The tumor volume of treatment group is small than NS group. TUNEL shows that the tumor of SCAP-DC-CIK group positive rate is highest and with the strongest positive bax expression and the weakest BCL-2,β-catenin expression . Conclusion: SCAP-DC-CIK have higher tumor-inhibitory effect than other treatment group.The mechanism may be by reduced expression of β- catenin to effect Wnt/β- catenin signaling pathway, and lead to an increased of bax and reduced of BCL - 2 expression to induce the apoptosis of tumor cell.

Key words: Breast cancer stem cell, DC, CIK, Bcl-2, Bax, β- catenin