Biological Characteristics And Antitumor Activity Of DC-CIK Cells Induced By Retronectin For K562Cells

Objective:To investigate the biological function and antitumor activity of the DC-CIK cells induced by the RetroNectin (RN), thus to establish a highly effective and simple way of cells culture for DC-CIK cells.Methods:The human peripheral blood monocuclear cells (PBMCs) were separated, then induced by DC-CIK conditioned medium to get large amouts of DC-CIK cells, which were grouped into the blank, the control and the experimental group, without the RN and DC-CIK conditioned medium(PBMCs group, as the blank one), without the RN (DC-CIK group, as the control one) or with the RN (RN-DC-CIK group, as the experimental one).The proliferation and cellular morphology was observed with the inverted microscope, the cell immunophenotypes detected by the flow cytometry, and the apoptosis measured by Annexin V-FITC Kit. The antitumor activity against K562cells in different effector-target ratios was detected wtih CCK-8kit in the experimental and control groups, IFN-y and IL-18levels detected by the enzyme-linked immunosorbent assay (ELISA), and the expression level of miRNA-21detected by the Real-Time Quantitative PCR(qRT-PCR).Results:1.The speed of propagation of the RN-DC-CIK group cells was significantly higher than the DC-CIK group cells by2-fold to3.5-fold (P<0.05), during the7days to14days. The cell maturation markers CD3+CD56+and CD86of both groups displayed a percentage increase with time, but of no statistical significance (P>0.05). The apoptosis rate of the RN-DC-CIK group cells and the control group were1.81±0.46%vs5.44±1.11%respectively, which was of statistical significance (P<0.05).2.The killing activity against the K562cells of the DC-CIK cells in both groups increased with the increasing effector to target ratios, showing statistical significance (P<0.05). And the killing rate of RN-DC-CIK group was higher than the DC-CIK group in the same effector to ratios, and the difference was statistically significant (P<0.05).3.The K562/RN-DC-CIK group displayed higher IFN-y and lower IL-18secretion than the K562/DC-CIK group, and the result was of statistical significance (P<0.05).4.The miRNA-21expression level in the K562/RN-DC-CIK group was significantly lower than the K562/DC-CIK group (P<0.05).Conclusions:1.The proliferation rate and anti-tumor activity of the DC-CIK cells could be improved by the RetroNectin.2.The miRNA-21expression could be blocked by the RetroNectin. May be one of the mechanisms which can enhance the antitumor activity of DC-CIK cells induced by RetroNectin.