Combination Therapy with EpCAM-CAR-NK-92 Cells and Regorafenib against Human Colorectal Cancer Models

J Immunol Res. 2018 Oct 15:2018:4263520. doi: 10.1155/2018/4263520. eCollection 2018.

Abstract

Adoptive chimeric antigen receptor-modified T or NK cells (CAR-T or CAR-NK) offer new options for cancer treatment. CAR-T therapy has achieved encouraging breakthroughs in the treatment of hematological malignancies. However, their therapeutic efficacy against solid tumors is limited. New regimens, including combinations with chemical drugs, need to be studied to enhance the therapeutic efficacy of CAR-T or NK cells for solid tumors. An epithelial cell adhesion molecule- (EpCAM-) specific second-generation CAR was constructed and transduced into NK-92 cells by lentiviral vectors. Immune effects, including cytokine release and cytotoxicity of the CAR-NK-92 cells against EpCAM-positive colon cancer cells, were evaluated in vitro. Synergistic effects of regorafenib and CAR-NK-92 cells were analyzed in a mouse model with human colorectal cancer xenografts. The CAR-NK-92 cells can specifically recognize EpCAM-positive colorectal cancer cells and release cytokines, including IFN-γ, perforin, and granzyme B, and show specific cytotoxicity in vitro. The growth suppression efficacy of combination therapy with regorafenib and CAR-NK-92 cells on established EpCAM-positive tumor xenografts was more significant than that of monotherapy with CAR-NK-92 cells or regorafenib. Our results provided a novel strategy to treat colorectal cancer and enhance the therapeutic efficacy of CAR-modified immune effector cells for solid tumors.

MeSH terms

  • Animals
  • Antineoplastic Agents / therapeutic use*
  • Cancer Vaccines / immunology*
  • Cell Line, Tumor
  • Colorectal Neoplasms / immunology
  • Colorectal Neoplasms / therapy*
  • Combined Modality Therapy
  • Cytotoxicity, Immunologic
  • Disease Models, Animal
  • Epithelial Cell Adhesion Molecule / immunology
  • Female
  • Humans
  • Immunotherapy, Adoptive / methods*
  • Interferon-gamma / metabolism
  • Killer Cells, Natural / physiology*
  • Killer Cells, Natural / transplantation
  • Mice
  • Mice, SCID
  • Phenylurea Compounds / therapeutic use*
  • Pyridines / therapeutic use*
  • Receptors, Chimeric Antigen / genetics
  • Tumor Burden
  • Xenograft Model Antitumor Assays

Substances

  • Antineoplastic Agents
  • Cancer Vaccines
  • EPCAM protein, human
  • Epithelial Cell Adhesion Molecule
  • Phenylurea Compounds
  • Pyridines
  • Receptors, Chimeric Antigen
  • regorafenib
  • Interferon-gamma