Experimental Study on the Combined Killing Effect of DC and CIK Cells on Gastric Cancer Stem Cells

Abstract

Background: Gastric cancer is one of the most fatal malignant tumors in China. Gastric cancer stem cells are the key factors of tumor recurrence and metastasis. In recent years, immunotherapy for gastric cancer stem cells has become a research hotspot. Objective: to preliminarily verify the combined killing effect of DC and CIK cells on gastric cancer stem cells. To evaluate the effect of DC-CIK cells as a potential therapeutic agents for gastric cancer. Methods: Based on human gastric cancer cell line SGC7901, gastric cancer stem cells were isolated and cultured by immunomagnetic beads. The cytotoxicity of DC-CIK effector cells to gastric cancer stem cells was investigated by 51Cr killing test. The cell cycle and apoptosis of tumor stem cells were detected by flow cytometry. Then the comparisions of the cytotoxicity activity between DC-CIK and CIK only was conducted. Results: the gastric cancer stem cells isolated and cultured by CD44 and CD133 immunomagnetic beads sorting method met the research requirements. 51Cr cell killing test results showed that the killing rate of DC-CIK combined as effector cells on gastric cancer SGC7901 stem cell line was significantly higher than those of the control group (P<0.05). After DC-CIK effector cells treatment, the apoptosis rate of tumor stem cells increased significantly. Conclusion: preliminary in vitro experiments show that DC-CIK cells combined as effector cells have obvious killing effect on gastric cancer stem cells, which could has potential clinical application value for controlling recurrence and metastasis of gastric cancer after surgery, radiotherapy and chemotherapy.