Effect of etoposide-induced alteration of the Mdm2-Rb signaling pathway on cellular senescence in A549 lung adenocarcinoma cells.

Effect of etoposide-induced alteration of the Mdm2-Rb signaling pathway on cellular senescence in A549 lung adenocarcinoma cells. Oncol Lett. 2017 Oct;14(4):3935-3940 Authors: Dai W, Jiang Y, Chen K, Qiu J, Sun J, Zhang W, Zhou X, Huang N, Li Y, Li W Abstract The present study aimed to investigate the effect of various concentrations of etoposide (VP-16) on the E3 ubiquitin-protein ligase Mdm2 (Mdm2)-retinoblastoma (Rb) signaling pathway in the cellular senescence of A549 lung adenocarcinoma cells. A549 cells were randomly divided into the following four groups: Control group (no treatment), group 1 (1 µmol/l VP-16), group 2 (5 µmol/l VP-16) and group 3 (25 µmol/l VP-16). Each group was cultured for 48 h after treatment prior to observation of the alterations to cellular morphology. The cell cycle distribution of each group was also detected by flow cytometry. In addition, the activity of cellular senescence-associated β-galactosidase, and the expression of Mdm2 and phosphorylated (p-) Rb protein, was measured. The percentage of senescent cells was significantly higher following VP-16 treatment compared with the control group. The percentage of G1 phase cells, and p-Rb protein and Mdm2 protein expression were also significantly different following VP-16 treatment compared with the control group. VP-16 increased the activity of β-galactosidase in the A459 cells. VP-16 also decreased the expression level of Mdm2 and p-Rb protein a...
Source: Oncology Letters - Category: Cancer & Oncology Tags: Oncol Lett Source Type: research