TY - JOUR T1 - NKG2D-directed Cytokine-activated Killer Lymphocyte Therapy Combined with Gemcitabine for Patients with Chemoresistant Metastatic Solid Tumors JF - Anticancer Research JO - Anticancer Res SP - 4529 LP - 4538 VL - 34 IS - 8 AU - TAKASHI MORISAKI AU - TATSUYA HIRANO AU - NORIHIRO KOYA AU - AKIFUMI KIYOTA AU - HIROTO TANAKA AU - MASAYO UMEBAYASHI AU - HIDEYA ONISHI AU - MITSUO KATANO Y1 - 2014/08/01 UR - http://ar.iiarjournals.org/content/34/8/4529.abstract N2 - Natural-killer group 2, member D (NKG2D) is an activating receptor found on activated natural killer cells and on activated T-cells, here termed cytokine-activated killer (CAK) cells. NKG2D ligands are expressed on various human cancer types. Gemcitabine is an anticancer drug which is a less immune-destructive agent than others. Herein, we investigated the clinical efficacy and the underlying mechanisms of a combination of CAK cell infusion therapy and gemcitabine. Twenty-three patients with disseminated carcinomas were treated with chemo-immunotherapy consisting of CAK cell infusion therapy following gemcitabine treatment. To investigate the underlying mechanisms by which CAK cells synergize with gemcitabine, we used enzyme-linked immunosorbent assay, Real-time reverse transcription polymerase chain reaction assay, calcein-release assay, and adherent target detachment assay. Using these assays we determined the NKG2D ligands such as major histocompatibility complex-class I-related chain (MIC)A/B expression in carcinoma cells and the level of cellular cytotoxicity generated by treatment with gemcitabine with/without CAK cells. The tumor responses differed among the patients (n=23). In vitro experiments revealed that MICA/B protein and mRNA expression were up-regulated in several carcinoma cell lines after gemcitabine treatment. Pre-treatment with gemcitabine and subsequent exposure to CAK cells induced greater cytotoxicity than either treatment alone. Inclusion of soluble MICB in CAK cell-mediated cytotoxicity assay significantly reduced cytotoxicity. Our clinical results of gemcitabine–CAK combinatorial therapy demonstrated long-term stable disease despite chemoresistance. In conclusion, the combination of gemcitabine and CAK cells may have clinical therapeutic significance for pancreatic, hepato-biliary tract, and urothelial tract cancer. Our study shows that combining CAK therapy with gemcitabine can lead to successful treatment of metastatic cancer. ER -