Bone marrow produces sufficient alloreactive natural killer (NK) cells in vivo to cure mice from subcutaneously and intravascularly injected 4T1 breast cancer

Breast Cancer Res Treat. 2017 Feb;161(3):421-433. doi: 10.1007/s10549-016-4067-6. Epub 2016 Dec 3.


Purpose: Administration of 5 million alloreactive natural killer (NK) cells after low-dose chemo-irradiation cured mice of 4T1 breast cancer, supposedly dose dependent. We now explored the efficacy of bone marrow as alternative in vivo source of NK cells for anti-breast cancer treatment, as methods for in vitro clinical scale NK cell expansion are still in developmental phases.

Methods: Progression-free survival (PFS) after treatment with different doses of spleen-derived alloreactive NK cells to 4T1-bearing Balb/c mice was measured to determine a dose-response relation. The potential of bone marrow as source of alloreactive NK cells was explored using MHC-mismatched mice as recipients of 4T1. Chemo-irradiation consisted of 2× 2 Gy total body irradiation and 200 mg/kg cyclophosphamide. Antibody-mediated in vivo NK cell depletion was applied to demonstrate the NK cell's role.

Results: Administration of 2.5 instead of 5 million alloreactive NK cells significantly reduced PFS, evidencing dose responsiveness. Compared to MHC-matched receivers of subcutaneous 4T1, fewer MHC-mismatched mice developed tumors, which was due to NK cell alloreactivity because in vivo NK cell depletion facilitated tumor growth. Application of low-dose chemo-irradiation increased plasma levels of NK cell-activating cytokines, NK cell activity and enhanced NK cell-dependent elimination of subcutaneous tumors. Intravenously injected 4T1 was eliminated by alloreactive NK cells in MHC-mismatched recipients without the need for chemo-irradiation.

Conclusions: Bone marrow is a suitable source of sufficient alloreactive NK cells for the cure of 4T1 breast cancer. These results prompt clinical exploration of bone marrow transplantation from NK-alloreactive MHC-mismatched donors in patients with metastasized breast cancer.

Keywords: 4T1; Alloreactive NK cell; Breast cancer; Hematopoietic stem cell transplantation; Immunotherapy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bone Marrow Transplantation
  • Breast Neoplasms / immunology*
  • Breast Neoplasms / mortality
  • Breast Neoplasms / pathology*
  • Breast Neoplasms / therapy
  • Cytokines / metabolism
  • Disease Models, Animal
  • Female
  • Immunotherapy* / methods
  • Killer Cells, Natural / immunology*
  • Killer Cells, Natural / metabolism
  • Lymphocyte Activation / immunology*
  • Major Histocompatibility Complex / genetics
  • Major Histocompatibility Complex / immunology
  • Mice
  • Mice, Inbred BALB C
  • Transplantation Conditioning
  • Whole-Body Irradiation


  • Cytokines