Purging Multiple Myeloma Cells Using Bortezomib and Lenalidomide
Posted: Wednesday, May 29, 2019
Treatment using bortezomib and lenalidomide against RPMI-8226 multiple myeloma cells may act as a purging method in removing contaminated plasma cells, according to preliminary study findings published in the Journal of Blood Medicine. If applicable to patient-derived stem cell grafts, this strategy may potentially improve the cure rate in patients with multiple myeloma, concluded A-Jin Lee, MD, and Sang-Gyung Kim, MD, of the Daegu Catholic University School of Medicine, Daegu, Korea, and colleagues.
“RPMI-8226 cells expressed two aberrant phenotypes of CD19−CD56+,” the authors observed. “These clonal cells were effectively removed by treatment with bortezomib and lenalidomide.”
The authors treated the human myeloma cell line RPMI-8226 with bortezomib or lenalidomide, whereas the mixture of the human peripheral blood monocular cell line PCS-800-011 and RPMI-8226 were treated with bortezomib or lenalidomide for 24 hours. The efficacy of purging myeloma cells was evaluated by eight-color flow-cytometric analysis.
After a 24-hour incubation with bortezomib at 10, 20, 40, 80, and 160 nmol/L, RPMI-8226 cells displayed growth inhibition of 5.45% ± 0.07%, 47.15% ± 1.20%, 57.15% ± 0.21%, 72.35% ± 0.07%, and 84.75% ± 0.49%, respectively. A 24-hour incubation with lenalidomide in RPMI-8226 cells exhibited growth inhibition of 5.45% ± 0.07%, 7.55% ± 0.07%, 9.75% ± 0.35%, 18.25% ± 0.21%, and 39.75% ± 0.78% at 200, 400, 800, 1,600, and 3,200 nmol/L, respectively.
The authors also observed that 40 nmol/L of bortezomib and 3,200 nmol/L of lenalidomide for 24 hours effectively removed CD38+CD138+ cells from peripheral mononuclear cells. Additionally, RPMI-8226 cells showed an aberrant phenotype CD56+/CD45−.
“Our results indicated that both drugs [bortezomib and lenalidomide] inhibited the proliferation of RPMI-8226 cells in a dose-dependent manner,” authors concluded.
Disclosure: The study authors reported no conflicts of interest.