Inhibitory Effect of NPM Gene Knockdown on Proliferation of Chronic Myeloid Leukemia Cell Line K562 and Its Mechanism / 中国实验血液学杂志

OBJECTIVE@#To investigate the role of nucleophosmin (NPM) in the proliferation of chronic myeloid leukemia cells (K562 cells) and its mechanism by RNAi technology.@*METHODS@#shRNA was used to inhibit the expression of NPM. The expression of NPM gene was detected by real-time quantitative PCR. The effect of inhibiting NPM gene on cell proliferation was detected by MTS assay. Change of cell cycle was detected by flow cytometry. Western blot was used to detect the expression of cell cycle-related proteins.@*RESULTS@#The shRNA lentiviral vector targeting at NPM gene was successfully constructed and used to transfect the K562 cells. The results showed that compared with the control groups, suppression of NPM gene expression in K562 cells could inhibit the cell proliferation and decrease the cell colony formation. Moreover, interference of NPM gene could prolong G/G phase and arrest cell cycle, which may be related to the down-regulation of NPM gene expression and activation of p21 protein expression, thereby inhibited the formation of CDK2/ Cyclin E complex.@*CONCLUSION@#Down-regulation of NPM gene expression in K562 cells can induce cell cycle arrest and inhibit cell proliferation.

Effect of Baicalin Derivative 02-036 on Burkitt Lymphoma Cell Line CA46 and Its Related Mechanisms / 中国实验血液学杂志

OBJECTIVE@#To investigate the effect of baicalin derivative 02-036 on proliferation and apoptosis human Burkitt lymphoma cell line CA46 and its related mechanisms.@*METHODS@#The MTT assay and cell colony formation assay were used to measure the growth inhibition of CA46 cells after 02-036 treatment. The flow cytometry with AnnexinV-FITC/PI double staining was employed to detect the apoptosis induction effect of 02-036 on CA46 cells. Cell cycle distribution of CA46 cells was estimeted by using DNA ploid analysis. Western blot was used to determine the changes of apoptosis-related proteins, including C-MYC, BCL-2, Procaspase-9, Procaspase-3, PARP and Cleaved-PARP.@*RESULTS@#Baicalin derivative 02-036 obviously inhibited the proliferation of CA46 cells, with dose- and time-dependent manner (r=0.963, r=0.992). The averaged IC value of CA46 cells was (6.04±0.11) μmol/L after 48-hour treatment. Low concentration of 02-036 could significantly inhibit the colony formation of CA46 cells. Flow cytometry analysis confirmed that 02-036 could effectively induce CA46 cell apoptosis. The apoptosis rate correlated with drug concentrations (r=0.959). Also, DNA ploid analysis showed that the cell cycle of CA46 was arrested in the S phase. The expression levels of BCL-2, Pro-caspase-9, Pro-caspase-3, PARP and C-MYC proteins decreased with a 02-036-dose dependent manner (r values were -0.990, -0.939, -0.971 and -0.967, respectively). In contrast, the expression level of cleaved-PARP increased with the same manner (r=0.920).@*CONCLUSION@#Baicalin derivative 02-036 can effectively inhibit the proliferation and induce apoptosis of CA46 cells, and its related mechanisms may be correlated with the down-regulation of apoptosis-related molecule expression levels, such as BCL-2, Pro-caspase-9, Pro-caspase-3, PARP and C-MYC.