Fig. 4: p21 contributes to resistance against apoptosis during senescence caused by decreased DNA methylation.

A RT-qPCR analysis of CDKN1A (p21) mRNA levels across indicated days of Dox/Auxin treatment. N = 3 biological replicates. B Immunoblots for p21 in the indicated condition. C Experimental scheme of p21 depletion and assessment. D Total cell numbers at the indicated days of Dox/Auxin. N = 3 technical replicates. E Immunoblots for DNMT1, UHRF1, and p21 in the nuclear and cytoplasmic fractions of indicated lines at Day 8 of Dox/Auxin treatment. F Immunoblots of p21, H2AX, γ-H2AX, full-length (FL) PARP, and cleaved PARP in the indicated lines at Day 8 of Dox/Auxin treatment. G Representative results of Annexin V/Hoechst 33342 double staining in the indicated conditions. H Quantification of Annexin V-positive cells at Day 8 of Dox/Auxin treatment. N = 3 technical replicates. I SA-β-gal staining (left panel) and quantification (right panel) of indicated lines. N = 5 fields of view. Scale bar is 50 µm. J RT-qPCR on CDKN1A (p21) and selected SASP genes in indicated conditions. Data of (A) are presented as mean ± SD and analyzed by one-way ANOVA with Dunnett’s multiple comparisons test. Data of D, H, I are presented as mean ± SD and analyzed by two-way ANOVA with Sidak’s multiple comparisons test. Heatmap data of J are presented as mean from three technical replicates. We use the following convention: *p < 0.05, ****p < 0.001, ****p < 0.0001, ns non-significant. Source data are provided as a Source Data file.