Combination Of Ibrutinib With Rituximab In Targeting Therapy Of Mantle Cell Lymphoma

ObjectiveTo explore the effects of Ibrutinib, an inhibitor of BTK (Bruton tyrosine kinase) and Rituximab, an anti-CD20 monoclonal antibody, as a single-agent or in combination for treatment of mantle cell lymphoma (MCL) cell line JeKo-1.Methods(1) Proliferation assay of JeKo-1 cells:Cultivate JeKo-1 cells and chose the cells in good growth state to drawing the growth curve by cell counting.(2) Cell viability assay for Ibrutinib as a single-agent:JeKo-1 cells were divided into Ibrutinib experimental group, Rituximab experimental group, self-control group and blank-control group. Experiment groups treated with varying concentrations of Ibrutinib or Rituximab. Self-control group was normal JeKo-1 cells, and the blank control group was culture medium without cells. After incubation for 24h,48h and 72h, cell viability was determined by CCK-8 assay. Differences between the groups were analysed by using ANOVA, and IC50 (half inhibitory concentration) analysis used GraphPad Prism 5 software.(3) Cell viability assay for combination of Ibrutinib with Rituximab: JeKo-1 cells were divided into Ibrutinib monotherapy group, Rituximab monotherapy group, combination of Ibrutinib with Rituximab group, self-control group and blank-control group. The monotherapy groups treated with varying concentrations of Ibrutinib (1μmol/L、5μmol/L、10μmol/L、15μmol/L、20μmol/L、 25μmol/L) or Rituximab (59.1μg/ml,76.9μg/ml,100.0μg/ml,130.0μg/ml). The combination group treated with the corresponding concentrations of Ibrutinib and Rituximab. Besides, the control groups treated as above. After incubation for 72h, cell viability was determined by CCK-8 assay. Analyze the effects and the combination index of the two drugs by using CompuSyn software.Results(1) The growth curve of JeKo-1 cells showed that cells were at the logarithmic growth phase in the 2-3 days and entered the plateau phase after the first three days.(2) It was significant (P<0.001) that Ibrutinib attenuated the viability of JeKo-1 cells in a concentration dependent manner at 24h,48h or 72h post treatment. It was significant that (p< 0.05) Ibrutinib attenuated the viability of JeKo-1 cells in a time-dependent manner at the same concentration post treatment as well. The IC50 of Ibrutinib was 17.11μmol/L for JeKo-1 cells for 72h.(3) It was significant (P<0.05) that Rituximab attenuated the viability of JeKo-1 cells in a concentration dependent manner at 72h post treatment. It was significant that (p< 0.05) Ibrutinib attenuated the viability of JeKo-1 cells in a time-dependent manner at the concentration of 50μg/ml, 100μg/ml and 250μg/ml post treatment as well.(4) The CI (combination index) values of Ibrutinib with Rituximab were range from 0.9 to 1.1, indicating that the combination of the two drugs was additive effect.Conclusion(1) Ibrutinib inhibited the proliferation of MCL cell line JeKo-1 in concentration-dependent and time-dependent manners, and the inhibition was obvious.(2) Rituximab inhibited the proliferation of MCL cell line JeKo-1 in concentration-dependent and time-dependent manners, but the inhibition wasn’t obvious (didn’t reach 10%).(3) Combination of Ibrutinib with Rituximab in targeting therapy of MCL cell line JeKo-1 showed additive effect but not synergistic or antagonistic.