Fig. 4: Anticancer drug treatment triggers the ubiquitination and proteasome-dependent PDR.
From: Suppressing protein damage response to overcome multidrug resistance in cancer therapy
a MDA-MB-231 cells were treated with indicated anticancer drugs (n = 11) for 1 h, and K48 polyUB was detected by western blotting. Quantifications of different damages were shown below. b Correlation between 101 anticancer drugs-induced protein aggregation and K48 polyUB. c Statistics of drugs-induced K48 polyUB in MDA-MB-231 cells at 1 h (n = 101) and 6 h (n = 115), and that in A549-6 h (n = 123). d, e Volcano plot showing changes in ubiquitinated protein levels after 6 h of CIS treatment (d), and the proteins with upregulated ubiquitination were analyzed using KEGG enrichment (e). f MDA-MB-231 cells were treated with indicated anticancer drugs alone or in combination with BTZ or TAK-243, and K48 polyUB and cleaved caspase 3 were detected by western blotting. g MDA-MB-231 cells were treated with CIS for indicated time periods, and K48 polyUB, γH2AX, and cleaved caspase 3 were detected by western blotting. h MDA-MB-231 cells were treated with CIS for 6 h and washed, and K48 polyUB, protein carbonylation, and γH2AX were detected by western blotting at 24 h and 48 h. i Nude mice bearing MDA-MB-231 xenograft tumors were treated with vehicle, CIS (3 mg/kg) or BTZ (1 mg/kg), and K48 polyUB and γH2AX were detected for tumors at 24 h, 48 h, and 72 h. Tumor tissues were harvested by needle biopsy from mouse 1 at 0, 24 and 48 h. Both mice 1 and 2 were sacrificed at 72 h for tumor collection. j MDA-MB-231 cells were treated with 2 EGFR inhibitors for indicated time periods, and K48 polyUB, p-EGFR, EGFR, p-AKT, AKT, and γH2AX were detected by western blotting. k MDA-MB-231 cells were treated with DOB or LAP, and DNA damage was detected by comet assay. l MDA-MB-231 cells were treated with indicated drugs, and K48 polyUB, p-CHK1, p-CHK2, p21, γH2AX were detected by western blotting. All values are presented as mean value (at least three replicates) ± SD, and P value was calculated by comparison with the Ctr group or indicated separately (two-tailed Student’s t-test, *P < 0.05, **P < 0.01, ***P < 0.001, NS, no significance).
