Fig. 5: Senolysis by PCC1 in the damaged TME diminishes SASP-conferred cancer resistance.
From: The flavonoid procyanidin C1 has senotherapeutic activity and increases lifespan in mice
a, Illustrative diagram of a preclinical regimen. Two weeks after subcutaneous implantation and in vivo uptake of tissue recombinants, NOD–SCID male mice received either single (mono) or combined (dual) agents in a metronomic schedule composed of several cycles. BLI, bioluminescence imaging. b, Statistical profiling of tumour end volumes. PC3 cells were xenografted alone or together with PSC27 cells into the hind flank of animals. c, Comparative evaluation of in vivo senescence by SA-β-Gal staining. Tumours were freshly dissected after killing animals and processed as frozen sections for histological staining. Scale bars, 200 μm. d, Violin plots depicting comparative statistics of SA-β-Gal staining in tumour tissues. e, Transcript assay for in vivo expression of several canonical SASP factors in stromal cells isolated from tumours. Tissues from animals xenografted with both stromal and cancer cells were subjected to laser capture microdissection-supported isolation and subsequent processes. Data are representative of three biological replicates (n = 10 animals per group). Datasets are displayed as box-and-whisker plots, in which a box extends from the 25th to the 75th percentile with the median shown as a line in the middle and whiskers indicating smallest and largest values. f, Profiling of SASP transcripts in stromal cells. Signals corresponding to each factor were normalized to those from the vehicle-treated group. Note p16INK4a is also known as CDKN2A and p21CIP1 is also known as CDKN1A. g, Statistical measurement of cells with DNA damage and apoptotic cells in biospecimens collected as described in a,b. Values are presented as the percentage of cells positively stained by immunohistochemistry (IHC) with antibodies specific to histone γH2AX or caspase 3 (cleaved). For b,d–g, P values were calculated by two-sided t-tests. h, Representative IHC images of caspase 3 (cleaved, CC3) at the end of the therapeutic regimes. Scale bars, 100 μm. i, Comparative survival of mice killed after the development of advanced bulky diseases. Survival duration was calculated from the time of recombinant tissue injection until animal death. MS, median survival. P values were calculated by two-sided log-rank (Mantel–Cox) tests. Data in c,h are representative of three independent experiments. Data in all bar graphs are shown as mean ± s.d. and are representative of three biological replicates.
