Mikala Egeblad

Differential expression analyses of CD8 T and macrophages populations of proliferating (p53 off) vs. senescent (p53 on) tumors by scRNA-seq.

Low (50 pg/ml) and high (1 ng/ml) dose of IFN-γ treatment in proliferating and senescent NSP cells.

Supplementary Video S1 from Senescence Rewires Microenvironment Sensing to Facilitate Antitumor Immunity

Supplementary Video S2 from Senescence Rewires Microenvironment Sensing to Facilitate Antitumor Immunity

Supplementary figures complement main figures to show that senescent cells have a rewired environmental signal sensing phenotype, exemplified by an enhanced IFN-g signaling, to facilitate anti-tumor immunity.

RNA-Seq data of proliferating (PRO) or senescent (SEN) NSP liver tumor cells, for both p53-restoration and drug-induced (trametinib+palbociclib) settings. PRO and SEN cells were also treated with the BET inhibitor JQ-1 (500 n, 48 h), to expose BRD4-mediated transcriptional output in each cellular state.

Cellular senescence involves a stable cell-cycle arrest coupled to a secretory program that, in some instances, stimulates the immune clearance of senescent cells. Using an immune-competent liver cancer model in which senescence triggers CD8 T cell–mediated tumor rejection, we show that senescence also remodels the cell-surface proteome to alter how tumor cells sense environmental factors, as exemplified by type II interferon (IFNγ). Compared with proliferating cells, senescent cells upregulate the IFNγ receptor, become hypersensitized to microenvironmental IFNγ, and more robustly induce the antigen-presenting machinery—effects also recapitulated in human tumor cells undergoing therapy-induced senescence. Disruption of IFNγ sensing in senescent cells blunts their immune-mediated clearance without disabling the senescence state or its characteristic secretory program. Our results demonstrate that senescent cells have an enhanced ability to both send and receive environmental signals and imply that each process is required for their effective immune surveillance.Significance:Our work uncovers an interplay between tissue remodeling and tissue-sensing programs that can be engaged by senescence in advanced cancers to render tumor cells more visible to the adaptive immune system. This new facet of senescence establishes reciprocal heterotypic signaling interactions that can be induced therapeutically to enhance antitumor immunity.See the interview with Direna Alonso-Curbelo, PhD, recipient of the inaugural Cancer Discovery Early Career Award: https://vimeo.com/992987447See related article by Marin et al., p. 410.This article is highlighted in the In This Issue feature, p. 247

Lineage plasticity is a hallmark of pancreatic ductal adenocarcinoma (PDAC) and contributes to tumor heterogeneity and therapeutic resistance. Here, we identify KLF5 as a dynamic master regulator of epithelial lineage identity in PDAC, with dichotomous roles in promoting either classical or basal-like transcriptional programs. Through unbiased proteomic and genetic screens, we uncover the AAA+ ATPases RUVBL1 and RUVBL2 as essential coactivators of KLF5 across both lineage states. We demonstrate that ATP hydrolysis by RUVBL1/2 is required for the stable interaction with an intrinsically disordered region of KLF5, enabling its recruitment to lineage-specific enhancers and driving transcriptional regulation of identity-defining genes. Notably, small-molecule inhibitors of RUVBL1/2 ATPase activity, which have anti-PDAC activity in vivo, suppress KLF5-dependent transcription. These findings define a previously unrecognized mechanism of ATP hydrolysis-dependent transcriptional coactivation and highlight a potential therapeutic strategy for modulating aberrant lineage programs in cancer.