Natural killer cell lines preferentially kill clonogenic multiple myeloma cells and decrease myeloma engraftment in a
Brenna E Swift1, Brent A Williams, Yoko Kosaka
1Cell Therapy Program, Princess Margaret Hospital, 610 University Ave, Toronto, ON, Canada.
Haematologica
|January 25, 2012
Summary
Natural killer (NK) cells effectively target and reduce both bulk and drug-resistant clonogenic multiple myeloma (MM) cells. NK cell therapy also decreased tumor burden in a mouse model, showing promise for MM treatment.
Area of Science:
- Immunology
- Hematology
- Cancer Biology
Background:
- Multiple myeloma (MM) treatment requires novel therapies targeting drug-resistant clonogenic cells.
- Natural killer (NK) cells are investigated as a potential therapeutic approach.
Purpose of the Study:
- To assess the cytotoxicity of NK cell lines against bulk and clonogenic MM cells.
- To evaluate the efficacy of NK cell therapy in reducing MM tumor burden in a preclinical model.
Main Methods:
- Cytotoxicity assays (chromium release, flow cytometry) were used to evaluate NK cell activity against MM cell lines.
- Clonogenic assays assessed the inhibition of self-renewal in residual MM progenitors post-NK cell treatment.
- A bioluminescent xenograft mouse model (U266eGFPluc) monitored disease progression and bone marrow engraftment after NK-92 cell therapy.
Main Results:
- NK-92 and KHYG-1 cell lines demonstrated significant cytotoxicity against MM cells, mediated by activating receptors (NKp30, NKp46, NKG2D, DNAM-1).
- NK cells exhibited 2- to 3-fold greater inhibition of clonogenic MM growth compared to bulk populations, achieving 89-99% cumulative inhibition.
- Intravenous NK-92 cell therapy reduced MM tumor burden and bone marrow engraftment in a xenograft mouse model.
Conclusions:
- NK-92 and KHYG-1 cell lines effectively kill both bulk and clonogenic multiple myeloma cells.
- NK cell therapy reduced tumor burden in a preclinical model, suggesting clinical relevance.
- Clinical studies of NK cell therapy for multiple myeloma are warranted due to the correlation between colony frequency and survival.
