ABSTRACT
Objective To investigate the effects on proliferation of multiple myeloma cell lines U266 and RPMI 8226 induced by puerariae radix flavones (PRF) in vitro and its possible mechanism.Methods Exposed to 0,10,30,50,100 μg/ml PRF for 48 h and 72 h,the U266 and RPMI 8226 cells proliferation inhibitory rates were detected by MTT assay,cell cycles by flow cytometry (FCM),morphologic changes of U266 cells by Wright' s staining,and early-stage apoptotic rates of U266 cells by FITC-Annexin V/PI staining with FCM.Analysis of DNA fragment was made to test characteristic apoptosis DNA ladder in U266 cells.Results 0,10,30,50,100 μg/ml PRF could inhibit the proliferation of U266 and RPMI 8226 cells in a dose-dependent manner (U266 ＞ RPMI 8226).Cell cycle analyses in U266 and RPMI 8226 cells showed that sub-diploid peaks,but cell cycles changed minor.Wright's staining of U266 cells showed hardly any apoptostic character istic.Annexin V/PI double staining indicated that early-stage apoptotic rates of U266 cells exposed to 0,10,30,50,100 μg/ml PRF for 48 h were mildly increased in a dose-dependent manner.They were (3.20±0.36) ％,(5.20±0.92) ％,(7.30±1.22) ％,(8.10±0.53) ％ and (10.80±0.90) ％,respectively.The group differences had statistical significance (P ＜ 0.05).Analysis of DNA fragment barely exhibited the characteristic DNA ladder in U266 cells.Conclusion A certain concentrations of PRF could inhibit the proliferation of U266 and RPMI 8226 cells significantly.It is suggested that apoptosis related to the proliferative inhibition mechanism induced by PRF in U266 cell line,but not main.Other pathways such as necrosis and autophagy whether or not involved need further investigation.
ABSTRACT
Objective: To investigate the effect of triptolide on cell proliferation, cell cycle distribution, DNA and protein expression regulation of P21wap1/cip1 and P27kip1 in human multiple myeloma RPMI 8226 cells. Methods: Cell viability was detected by MTT assay and cell cycle distribution was measured by flow cytometry. Effect on mRNA expression of P21wap1/cip1 and P27kip1 was detected by RT-PCR. The change of protein expression was measured by Western blotting. Results: Triptolide of varying concentration significantly induced the inhibition of proliferation in a dose-dependent manner and G0/G 1 phase arrest of the cell cycle progression. The events were coincided with the upregulation of the mRNA and protein expression of P21wap1/cip1 and P27kip1. Conclusion: These results suggest that triptolide might exhibit its strong antitumor effect via alternation of P21wap1/cip1 and P27kip1. It provides framework for a clinical evaluation of triptolide.