[Effect of RITA on TP53 Mutant Human Mantle Cell Lymphoma Cell Line and Its Mechanism]

To investigate the effect of RITA on TP53 mutant human mantle cell lymphoma (MCL) cell line Mino and its possible mechanism.

Mino cells were cultured in RPMI-1640 and treated with RITA at a concentration of 0-16 μmol/L for 24,48,72 hours. Cell viability was assessed by CCK-8 assay. The cells were treated by RITA (0-8 μmol/L) for 48 h, the cell apoptosis induced by RITA was detected by annexin V/PI flow cytometry. Western blot was performed to evaluate the expression of protein BCL-2, Caspase-3, Cleaved Caspase-3, PARP, MDM2, and P53 in Mino cells.

After treatment with 0.5, 1, 2, 4, 8, and 16 μmol/L RITA for 48 h, the proliferation inhibition rate of Mino cells was (1.2±5.6)%, (14.9±4.9)%, (41.7±5.0)%, (61.8±2.4)%, (70.2±2.8)%, and (70.8±2.4)%, respectively. RITA could inhibit the proliferation of Mino cells significantly, and statistical analysis showed that the inhibition rate was increased with the increasing of RITA concentration (r=0.767). After the cells were treated by 4 μmol/L RITA for 24, 48, and 72 h, the proliferation inhibition rate was (25.2±3.8)%, (61.8±2.4)%, and (87.0±0.7)%, respectively. Satistical analysis showed that the inhibition rate was also increased with the increasing of treatment time (r=0.978). The apoptosis rate of Mino cells treated by 0, 2, 4, and 8 μmol/L RITA for 48 h was (5.4±0.4)%, (15.3±0.6)%, (38.7±1.7)%, and (50.8±1.1)%, respectively, and it showed dose-dependent manner (r=0.961). Western blot showed that with the increasing of RITA concentration, the BCL-2 protein expression was decreased in a dose-dependent manner (r=0.932), moreover, PARP cleavage and Caspase-3 activation were found, while the protein expression of MDM2 and P53 showed no change.

RITA can inhibit the proliferation and induce the apoptosis of Mino cells significantly. The mechanism may be dependent on the Caspase pathway, but independent on the P53 pathway.