In Vitro Cytotoxic Activity of Irradiated NK-92 Cells against Human Cervical Cancer Cells

Objective To study in vitro cytotoxic activity of NK-92 cells against human cervical cancer cells and effect of irradiation on NK-92 cytotoxicity.Methods NK-92 cells were mixed with 51 Cr-labeled Hela or K562 cells at different effector-to-target ratios for a 4h 51 Cr-release assay. On the other hand, NK-92 cells were irradiated at 0 and 400 cGy and tested after 2d for cytotoxicity against K562 and Hela cells.Results NK-92 cells (0 cGy) displayed high in vitro cytotoxicity against Hela with a mean specific lysis of 47% and 50% at 10∶1 and 20∶1 E∶T ratios , while these levels at 1∶1 (15 %) and 5∶1 (33 %) E∶T ratios were lower; The cytotoxicity of NK-92 against K562 ranged from 33 % to 69 %. NK–92 cells maintained up to 14 %～47 % cytotoxicity against Hela and 30%～60% cytotoxicity against K562 when irradiated with 400cGy after 2d.Conclusion In vitro cytotoxic activity of NK-92 cells against Hela cells is high at suitable E∶T ratios,and substantial cytotoxicity can be retained up to irradiation dose of 400cGy.