Fig. 1: Chemotherapy-induced senescent lung cancer cells abundantly secrete MMP-7 as part of their SASP.
a, A549 lung adenocarcinoma cells were treated with chemotherapy drugs for 10 days. b, Senescence induction was assessed by SA-β-gal activity staining (scale bars = 100 µm). Conditioned media of these senescent cells was screened for protease biomarkers. Figure created in BioRender. Fruk, L. (2026) https://BioRender.com/afyvgy3. c, Relative level of proteases secreted by chemotherapy-induced senescent cells and untreated A549 cells (n = 3 independent biological replicates per group except for n = 4 independent biological replicates for pemetrexed group, mean ± standard deviation (s.d.), two-way analysis of variance (ANOVA) with Dunnett’s multiple comparisons). d, Concentration of MMP-7 in the conditioned media from senescent and non-senescent A549 cells (n = 8 independent biological replicates for the untreated group, n = 4 independent biological replicates for the palbociclib/docetaxel/pemetrexed group, n = 3 independent biological replicates for the cisplatin group; mean ± s.d., ordinary one-way ANOVA with Dunnett’s multiple comparisons). e, Schematic representation of experimental layout. Briefly, mice, transplanted subcutaneously with A549 cells, were subjected to pemetrexed treatment, cisplatin treatment or vehicle at the timings depicted. Peripheral blood was collected before treatment and at the endpoint (day 13). Tumors were resected at day 13 after initiation of treatment (n = 5 independent mice for the cisplatin and vehicle groups, n = 6 independent mice for the pemetrexed group). Mouse figure was created in BioRender. Fruk, L. (2026) https://BioRender.com/ruw7v3q. f, Quantification of SA-β-gal+, pRb+, p21+ and MMP-7+ cells per total cells in vehicle-treated or drug-treated specimens (mean ± s.d., ordinary one-way ANOVA with Dunnett’s multiple comparisons). g, Representative histology images of tumor specimens resected from vehicle-treated or drug-treated mice and subjected to SA-β-gal, pRb, p21 and MMP-7 staining (performed on consecutive sections). Scale bars = 50 μm and 1 mm, as depicted.
