Inhibition of WEE1 kinase and cell cycle checkpoint activation sensitizes head and neck cancers to natural killer cell therapies

J Immunother Cancer. 2018 Jun 21;6(1):59. doi: 10.1186/s40425-018-0374-2.


Background: Natural killer (NK) cells recognize and lyse target tumor cells in an MHC-unrestricted fashion and complement antigen- and MHC-restricted killing by T-lymphocytes. NK cells and T-lymphocytes mediate early killing of targets through a common granzyme B-dependent mechanism. Tumor cell resistance to granzyme B and how this alters NK cell killing is not clearly defined.

Methods: Tumor cell sensitivity to cultured murine KIL and human high affinity NK (haNK) cells in the presence or absence of AZD1775, a small molecule inhibitor of WEE1 kinase, was assessed via real time impedance analysis. Mechanisms of enhanced sensitivity to NK lysis were determined and in vivo validation via adoptive transfer of KIL cells into syngeneic mice was performed.

Results: Cultured murine KIL cells lyse murine oral cancer 2 (MOC2) cell targets more efficiently than freshly isolated peripheral murine NK cells. MOC2 sensitivity to granzyme B-dependent KIL cell lysis was enhanced by inhibition of WEE1 kinase, reversing G2/M cell cycle checkpoint activation and resulting in enhanced DNA damage and apoptosis. Treatment of MOC2 tumor-bearing wild-type C57BL/6 mice with AZD1775 and adoptively transferred KIL cells resulted in enhanced tumor growth control and survival over controls or either treatment alone. Validating these findings in human models, WEE1 kinase inhibition sensitized two human head and neck cancer cell lines to direct lysis by haNK cells. Further, WEE1 kinase inhibition sensitized these cell lines to antibody-dependent cell-mediated cytotoxicity when combined with the anti-PD-L1 IgG1 mAb Avelumab.

Conclusions: Tumor cell resistance to granzyme B-induced cell death can be reversed through inhibition of WEE1 kinase as AZD1775 sensitized both murine and human head and neck cancer cells to NK lysis. These data provide the pre-clinical rationale for the combination of small molecules that reverse cell cycle checkpoint activation and NK cellular therapies.

Keywords: Antibody-dependent cell-mediated cytotoxicity; DNA damage checkpoint; KIL cells; NK cells; Resistance; WEE1 kinase; haNK cells.

Publication types

  • Research Support, N.I.H., Intramural

MeSH terms

  • Animals
  • Antibody-Dependent Cell Cytotoxicity / genetics
  • Antibody-Dependent Cell Cytotoxicity / immunology
  • Biomarkers
  • Cell Cycle Checkpoints / drug effects*
  • Cell Cycle Proteins / antagonists & inhibitors*
  • Cell Line, Tumor
  • Combined Modality Therapy
  • Cytotoxicity, Immunologic / genetics
  • DNA Damage
  • Granzymes / genetics
  • Head and Neck Neoplasms / immunology*
  • Head and Neck Neoplasms / metabolism
  • Head and Neck Neoplasms / pathology
  • Head and Neck Neoplasms / therapy
  • Humans
  • Immunotherapy* / methods
  • Killer Cells, Natural / drug effects*
  • Killer Cells, Natural / immunology*
  • Killer Cells, Natural / metabolism
  • Mice
  • Nuclear Proteins / antagonists & inhibitors*
  • Protein Kinase Inhibitors / pharmacology*
  • Protein Kinase Inhibitors / therapeutic use
  • Protein-Tyrosine Kinases / antagonists & inhibitors*


  • Biomarkers
  • Cell Cycle Proteins
  • Nuclear Proteins
  • Protein Kinase Inhibitors
  • Protein-Tyrosine Kinases
  • WEE1 protein, human
  • Granzymes