All cell lines were obtained from the Type Culture Collection of the Chinese Academy of Sciences (Shanghai, China). Drug resistant cells SGC-R and BGC-R cells were developed from SGC7901 and BGC823, respectively 16 (link). All cell lines were cultured as previously reported. The chemical reagents including Dichloroacetic acid (DCA) (D54702), KNK437 (SML0964), Cycloheximide (R750107), chloroquine (C6628), MG132 (474790) and PD150606 (D5946) were purchased from Sigma Aldrich (USA). MLN4924 (B1036) and radicicol (A4067) were purchased from ApexBio (USA). Cisplatin and KRIBB11 (S840201) were obtained from Selleck (Shanghai, China).