Figure 6 from APOBEC3 Activity Promotes the Survival and Evolution of Drug-Tolerant Persister Cells during EGFR Inhibitor Resistance in Lung Cancer
Year: 2025
Type: other
Abstract: p63 knockout reduces inflammatory gene expression and sensitizes PC9 GR cells to EGFR inhibition. A, Dose–response curve of osimertinib in gefitinib-sensitive and GR PC9 cells expressing A3B. Viability was measured using CellTiter Glo following 3 days of drug treatment. A two-way ANOVA with the Tukey multiple comparisons test was used to determine statistical significance at each dose. ****, P < 0.0001 when comparing PC9 A3B-on GRF and GRE cells at the indicated dose. B, Western blots for pEGFR (Y1068) and total EGFR in gefitinib-sensitive and GR PC9 cells expressing A3B. Cells were treated with osimertinib (Osi) for 24 hours. C, Western blots for p63α in PC9 A3B-on GRF cells expressing an empty vector or gRNAs targeting p63 (sg1 and sg3). PC9 A3B-on F cells are shown as a control. D, qRT-PCR analysis showing IL-1A and IL-1B expression in PC9 A3B-on GRF cells expressing an empty vector or gRNAs targeting p63 (sg1 and sg3). PC9 A3B-on F cells are shown as a control. Error bars represent SEM of three technical replicates. An unpaired t test was performed to determine statistical significance. **, P < 0.005; ****, P < 0.0001. E, In vitro growth curves of PC9 A3B-on GRF cells with or without p63 knockout. A two-way ANOVA was performed to determine statistical significance. ns, not significant. F, Dose–response curve of osimertinib in PC9 A3B-on GRF cells expressing an empty vector or gRNAs targeting p63 (sg1 and sg3). Viability was measured using CellTiter Glo following 3 days of drug treatment. A two-way ANOVA was performed, which determined a significant p63 status × dose interaction with a P value of 0.02. G, Viability of PC9 A3B-on GRF cells expressing an empty vector or gRNAs targeting p63 (sg1 and sg3) following treatment with osimertinib for 6 days. A two-way ANOVA with the Dunnett test was performed to determine statistical significance. ****, P < 0.00001. H, Model for the function of APOBEC3 in the survival and evolution of DTP cells during acquired resistance to EGFR inhibition. EGFR inhibition leads to STAT1-dependent upregulation of A3A and A3B. The expression of A3A and A3B is required for the survival of DTPs and is associated with an increased frequency of ∆Np63 upregulaiton and squamous transdifferentiation in the drug-resistant state. ∆Np63 expression in drug-resistant cells promotes osimertinib resistance in part through upregulation of EGFR ligands.
Language: English
Subfield: Pulmonary and Respiratory Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: gold
OpenAlex ID: W4410565961