Western blot. Once cell were 80% confluent, they were lysed with appropriate buffer. Protein concentrations were determined using the Pierce BCA Protein Assay Kit (NCI1059CH, Thermo, Waltham, MA, USA) and then adjusted to the same level. Protein were denatured by heating at 100๐C for 5 min, subjected to SDS-PAGE electrophoresis, and transferred to membranes. For immunoblotting, the membranes were incubated with primary antibodies at 4๐C overnight and then with secondary antibodies for 1 h at room temperature. Enhanced chemiluminescent substrate was added for gel imaging or film exposure. Images were collected using a Chemi DOC XRS + Imaging system (BioRad, Hercules. CA. USA). The gray scale value of protein bands was scanned using Image Lab 5.0 (BioRad, Hercules. CA. USA).