2.9. Western blot analysis

Western blot assay was performed according to a previous study. ²⁴ Primary antibodies against various proteins were as follows: anti‐cleaved caspase‐3, anti‐cleaved caspase‐8, anti‐cleaved caspase‐9, anti‐BCL2, anti‐BCL‐XL, anti‐BAX were obtained from Cell Signaling Technology (CST, Beverly, USA); anti‐CDK4, anti‐CDK6, anti‐CyclinD1, anti‐Trip13, anti‐Ku70, anti‐Ku80, anti‐H2AX, anti‐phospho‐ H2AX (γ‐H2AX), anti‐CHK2, anti‐phospho‐CHK2 (Thr68), anti‐ATM, anti‐phospho‐ATM (Ser1981), and anti‐GAPDH were obtained from Abcam (Cambridge, MA, USA); anti‐β‐actin was obtained from Sigma (S. Louis, MO, USA).