Inhibitory effects of the phosphoinostitide-3'-kinase delta inhibitor CAL-101 on Raji and SUDHL-10 lymphoma cells and its relative mechanism / 中国肿瘤临床

ABSTRACT

Objective:To detect the inhibitory effects of CAL-101, a selective inhibitor of phosphoinostitide-3'-kinase delta (PI3Kδ), on Burkitt's lymphoma cell line Raji and diffused large B-cell lymphoma cell line SUDHL-10 and elucidate its relative mechanism. Methods:Raji and SUDHL-10 cells were treated with various concentrations of CAL-101. Methyl thiazolyl tetrazolium (MTT) assay was performed to determine the inhibitory effect of CAL-101 on lymphoma cells, and cell apoptosis was measured by Annexin V/PI and DAPI staining. Migration assays were performed with transwell to detect the migration of lymphoma cells derived from the stromal cell line HK. Western blot was used to detect the phosphorylation status of the ERK pathway. MTT and CalcuSyn software analyses were preformed to detect whether or not combining CAL-101 with bortezomib induces synergistic cytoxicity. Results:CAL-101 at con-centrations of 5, 10, 15, and 20μmol/L inhibited cell proliferation in a dose-dependent manner. The proliferation rates of the Raji cells treated with 5, 10, 15, and 20μmol/L for 48 h were 29.17%± 1.23%, 38.15%± 1.51%, 46.46%± 1.78%, and 55.8%± 2.01%, respec-tively, which were significantly higher (P<0.05) than that of the control group (1.15% ± 0.02%). Similar results were found in the SUDHL-10 cells after treatment with CAL-101 (P<0.05). CAL-101 also exerted an apoptotic effect on the lymphoma cells. The apop-totic rates of the Raji cells treated with CAL-101 for 21 h were 22.69%± 3.83%and 49.96%± 7.36%, respectively, which were signifi-cantly higher (P<0.05) than that of the control group (5.23%± 2.04%). Similar results were found in the SUDHL-10 cells (P<0.05). Treatment with 5 and 10 μmol/L CAL-101 dose-dependently inhibited the migration activity of lymphoma cells to stromal cells (P<0.05). Western blot analysis showed that the expression level of ERK phosphorylation protein was significantly downregulated in the cells treated with CAL-101. A synergistic effect between CAL-101 and bortezomib was verified. That is, these two drugs can signifi-cantly inhibit the proliferation of lymphoma cells with CI values less than 1. Conclusion:The PI3Kδ-specific inhibitor CAL-101 sup-pressed the proliferation of Raji and SUDHL-10 cells, induced apoptosis, and inhibited stromal cell-derived migration. This inhibitory effect may be induced by blocking the ERK pathway. Overall, our study indicated that CAL-101 is a novel and potential agent in the therapeutic strategy against aggressive B-cell lymphoma.