title: Contrasting Effects of the Cytotoxic Anticancer Drug Gemcitabine and the EGFR Tyrosine Kinase Inhibitor Gefitinib on NK Cell-Mediated Cytotoxicity via Regulation of NKG2D Ligand in Non-Small-Cell Lung Cancer Cells.
abstract: BACKGROUND
  Several cytotoxic anticancer drugs inhibit DNA replication and/or mitosis, while EGFR tyrosine kinase inhibitors inactivate EGFR signalling in cancer cell. Both types of anticancer drugs improve the overall survival of the patients with non-small-cell lung cancer (NSCLC), although tumors often become refractory to this treatment. Despite several mechanisms by which the tumors become resistant having been described the effect of these compounds on anti-tumor immunity remains largely unknown.
  
  
  METHODS
  This study examines the effect of the cytotoxic drug Gemcitabine and the EGFR tyrosine kinase inhibitor Gefitinib on the expression of NK group 2 member D (NKG2D) ligands as well as the sensitivity of NSCLC cells to the NK-mediated lysis.
  
  
  RESULTS
  We demonstrate that Gemcitabine treatment leads to an enhanced expression, while Gefitinib downregulated the expression of molecules that act as key ligands for the activating receptor NKG2D and promote NK cell-mediated recognition and cytolysis. Gemcitabine activated ATM and ATM- and Rad-3-related protein kinase (ATR) pathways. The Gemcitabine-induced phosphorylation of ATM as well as the upregulation of the NKG2D ligand expression could be blocked by an ATM-ATR inhibitor. In contrast, Gefitinib attenuated NKG2D ligand expression. Silencing EGFR using siRNA or addition of the PI3K inhibitor resulted in downregulation of NKG2D ligands. The observations suggest that the EGFR/PI3K pathway also regulates the expression of NKG2D ligands. Additionally, we showed that both ATM-ATR and EGFR regulate MICA/B via miR20a.
  
  
  CONCLUSIONS
  In keeping with the effect on NKG2D expression, Gemcitabine enhanced NK cell-mediated cytotoxicity while Gefitinib attenuated NK cell killing in NSCLC cells.
authors.affiliation: Department of General Thoracic Surgery, Kawasaki Medical School, Kurashiki, Japan; Department of Oncology and Pathology, Immune and Gene Therapy Laboratory, Cancer Center Karolinska, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Riki
authors.initials: R
authors.lastname: Okita
authors.affiliation: Institute of Medical Immunology, Martin Luther University, Halle-Wittenberg, Halle, Germany.
authors.forename: Diana
authors.initials: D
authors.lastname: Wolf
authors.affiliation: Department of General Thoracic Surgery, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Koichiro
authors.initials: K
authors.lastname: Yasuda
authors.affiliation: Department of General Thoracic Surgery, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Ai
authors.initials: A
authors.lastname: Maeda
authors.affiliation: Department of General Thoracic Surgery, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Takuro
authors.initials: T
authors.lastname: Yukawa
authors.affiliation: Department of General Thoracic Surgery, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Saisho
authors.affiliation: Department of General Thoracic Surgery, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Shimizu
authors.affiliation: Department of Clinical Oncology, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Yamaguchi
authors.affiliation: Department of Respiratory Medicine, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Mikio
authors.initials: M
authors.lastname: Oka
authors.affiliation: Faculty of Health and Welfare, Kawasaki University of Medical Welfare, Kurashiki, Japan.
authors.forename: Eiichi
authors.initials: E
authors.lastname: Nakayama
authors.affiliation: Department of Oncology and Pathology, Immune and Gene Therapy Laboratory, Cancer Center Karolinska, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Andreas
authors.initials: A
authors.lastname: Lundqvist
authors.affiliation: Department of Oncology and Pathology, Immune and Gene Therapy Laboratory, Cancer Center Karolinska, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Rolf
authors.initials: R
authors.lastname: Kiessling
authors.affiliation: Institute of Medical Immunology, Martin Luther University, Halle-Wittenberg, Halle, Germany.
authors.forename: Barbara
authors.initials: B
authors.lastname: Seliger
authors.affiliation: Department of General Thoracic Surgery, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Masao
authors.initials: M
authors.lastname: Nakata
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D002289:Carcinoma, Non-Small-Cell Lung / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D003602:Cytotoxicity, Immunologic / Q000187:drug effects*; D003841:Deoxycytidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D066246:ErbB Receptors / Q000037:antagonists & inhibitors; D000077156:Gefitinib; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D008175:Lung Neoplasms / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D055655:NK Cell Lectin-Like Receptor Subfamily K / Q000235:genetics / Q000378:metabolism*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D011799:Quinazolines / Q000494:pharmacology*; D000093542:Gemcitabine
chemical_list: D000970:Antineoplastic Agents; C527085:KLRK1 protein, human; D055655:NK Cell Lectin-Like Receptor Subfamily K; D047428:Protein Kinase Inhibitors; D011799:Quinazolines; D003841:Deoxycytidine; D066246:ErbB Receptors; D000077156:Gefitinib; D000093542:Gemcitabine