Fig. 4

APE1 deficiency leads to increased Artemis protein degradation. a Protein expression levels of Artemis in NC and shAPE1 of SiHa and HeLa cells or c in the multiple organs in Ape1 WT and KO mice were assessed by immunoblotting. b mRNA expression level of Artemis in NC and shAPE1 cells of SiHa and HeLa cells were assessed by qRT-PCR. d–e HeLa shAPE1 cells were treated with MG132 (10 μM) for 8 h d, HeLa NC and shAPE1 cells were treated with cycloheximide (CHX) for 1 and 5 h e, then Artemis levels were assayed by immunoblotting. f The ubiquitination of Artemis was significantly increased in the HeLa shAPE1 cell line. HeLa ^NC+Ubb, HeLa ^shAPE1+Ubb, HeLa ^{NC+Ubb+Flag−Artemis} and HeLa ^{shAPE1+Ubb+Flag−Artemis} cells were treated with MG132. Exogenous expressed Artemis was immunoprecipitated by Flag antibody. And ubiquitination of Artemis was then analyzed by anti-Ubb immunoblotting. g, i HeLa WT cell line was transfected with si-NC and si-Artemis g, HeLa shAPE1 cells were transfected the vector of Flag-NC and Flag-Artemis i, the knockdown or overexpression of Artemis was confirmed by immunoblotting. h, j cells from g, i were treated with TBHP for 1 h, and apoptosis were analyzed by flow cytometry 48 h later. k HeLa WT cell line was transfected with si-NC, si-Artemis, shAPE1 or both, then cells were treated with TBHP for 1 h, and apoptosis were analyzed by flow cytometry 48 h later. l The Artemis protein expression was positively correlated with the APE1 protein expression in cervix cancer tissues. m The tissue expression of Artemis was evaluated by IHC in 46 cervix cancer patients receiving radical chemo-radiotherapy. Protein levels were scored for four categories: score-, score + , score +  + , and score +  +  + . n Kaplan–Meier plot showing different overall survival of cervical cancer patients according to Artemis expression. The p-values were determined using an unpaired Student’s t-test (*p < 0.05). The data were presented as the mean ± SEM from three independent experiments