IL-21 Enhances Natural Killer Cell Response to Cetuximab-Coated Pancreatic Tumor Cells

• Published in: Clinical cancer research 2017-01, Vol.23 (2), p.489-502
• Main Authors: McMichael, Elizabeth L, Jaime-Ramirez, Alena Cristina, Guenterberg, Kristan D, Luedke, Eric, Atwal, Lakhvir S, Campbell, Amanda R, Hu, Zhiwei, Tatum, Armika S, Kondadasula, Sri Vidya, Mo, Xiaokui, Tridandapani, Susheela, Bloomston, Mark, Ellison, E Christopher, Williams, Terence M, Bekaii-Saab, Tanios, Carson, 3rd, William E
• Format: Article
• Language: English
• Subjects: Animals; Antibody-Dependent Cell Cytotoxicity - drug effects; Biotechnology; Cancer; Cell activation; Cell Line, Tumor; Cetuximab - administration & dosage; Chemokines; Chemotaxis; Chemotaxis - drug effects; Chemotaxis - immunology; Coating effects; Effectiveness; Epidermal growth factor receptors; Experimental design; Flow Cytometry; Gemcitabine; Humans; Immunotherapy; Interferon; Interferon-gamma - biosynthesis; Interferon-gamma - immunology; Interleukin 21; Interleukins - immunology; Interleukins - metabolism; K-Ras protein; Killer Cells, Natural - immunology; Lymphocyte Activation - drug effects; Lymphocyte Activation - immunology; Lymphocytes; Lymphocytes T; Lysis; Metastases; Mice; Monoclonal antibodies; Mutation; Natural killer cells; Pancreatic cancer; Pancreatic Neoplasms - genetics; Pancreatic Neoplasms - immunology; Pancreatic Neoplasms - pathology; Pancreatic Neoplasms - therapy; Patients; Proto-Oncogene Proteins p21(ras) - genetics; Signal transduction; Stat1 protein; T cell receptors; T-Lymphocytes - drug effects; T-Lymphocytes - immunology; Targeted cancer therapy; Therapy; Tumor cell lines; Tumor cells; Xenograft Model Antitumor Assays; Xenografts; γ-Interferon
• ISSN: 1078-0432; 1557-3265
• DOI: 10.1158/1078-0432.CCR-16-0004

Alternative strategies to EGFR blockage by mAbs is necessary to improve the efficacy of therapy in patients with locally advanced or metastatic pancreatic cancer. One such strategy includes the use of NK cells to clear cetuximab-coated tumor cells, as need for novel therapeutic approaches to enhance the efficacy of cetuximab is evident. We show that IL-21 enhances NK cell-mediated effector functions against cetuximab-coated pancreatic tumor cells irrespective of KRAS mutation status. NK cells from normal donors or donors with pancreatic cancer were used to assess ADCC, IFN-γ release, and T-cell chemotaxis toward human pancreatic cancer cell lines. The in vivo efficacy of IL-21 in combination with cetuximab was evaluated in a subcutaneous and intraperitoneal model of pancreatic cancer. NK cell lysis of cetuximab-coated wild-type and mutant kras pancreatic cancer cell lines were significantly higher following NK cell IL-21 treatment. In response to cetuximab-coated pancreatic tumor cells, IL-21-treated NK cells secreted significantly higher levels of IFN-γ and chemokines, increased chemotaxis of T cells, and enhanced NK cell signal transduction via activation of ERK and STAT1. Treatment of mice bearing subcutaneous or intraperitoneal EGFR-positive pancreatic tumor xenografts with mIL-21 and cetuximab led to significant inhibition of tumor growth, a result further enhanced by the addition of gemcitabine. These results suggest that cetuximab treatment in combination with IL-21 adjuvant therapy in patients with EGFR-positive pancreatic cancer results in significant NK cell activation, irrespective of KRAS mutation status, and may be a potential therapeutic strategy. Clin Cancer Res; 23(2); 489-502. ©2016 AACR.