Project description:Immunotherapies that produce durable responses in some malignancies have failed in pancreatic ductal adenocarcinoma (PDAC) due to rampant immune suppression and poor tumor immunogenicity. We and others have demonstrated that induction of the senescence-associated secretory phenotype (SASP) can be an effective approach to activate anti-tumor Natural Killer (NK) and T cell immunity. Here we found the pancreas tumor microenvironment (TME) suppresses NK and T cell surveillance following therapy-induced senescence through EZH2-mediated epigenetic repression of pro-inflammatory SASP genes. EZH2 blockade stimulated production of SASP chemokines CCL2 and CXCL9/10, leading to enhanced NK and T cell infiltration and PDAC eradication in mouse models. EZH2 activity was also associated with suppression of chemokine signaling and cytotoxic lymphocytes and reduced survival in PDAC patients. These results demonstrate that EZH2 represses of the pro-inflammatory SASP, and that EZH2 inhibition combined with senescence-inducing therapy could be a powerful means to achieve immune-mediated tumor control in PDAC.
Project description:Immunotherapies that produce durable responses in some malignancies have failed in pancreatic ductal adenocarcinoma (PDAC) due to rampant immune suppression and poor tumor immunogenicity. We and others have demonstrated that induction of the senescence-associated secretory phenotype (SASP) can be an effective approach to activate anti-tumor Natural Killer (NK) and T cell immunity. Here we found the pancreas tumor microenvironment (TME) suppresses NK and T cell surveillance following therapy-induced senescence through EZH2-mediated epigenetic repression of pro-inflammatory SASP genes. EZH2 blockade stimulated production of SASP chemokines CCL2 and CXCL9/10, leading to enhanced NK and T cell infiltration and PDAC eradication in mouse models. EZH2 activity was also associated with suppression of chemokine signaling and cytotoxic lymphocytes and reduced survival in PDAC patients. These results demonstrate that EZH2 represses of the pro-inflammatory SASP, and that EZH2 inhibition combined with senescence-inducing therapy could be a powerful means to achieve immune-mediated tumor control in PDAC.
Project description:Oncogene-induced senescence (OIS) and therapy-induced senescence (TIS), while tumor-suppressive, also promote procarcinogenic effects by activating the DNA damage response (DDR), which in turn induces inflammation. This inflammatory response prominently includes an array of cytokines known as the senescence-associated secretory phenotype (SASP). Previous observations link the transcription-associated methyltransferase and oncoprotein MLL1 to the DDR, leading us to investigate the role of MLL1 in SASP expression. Our findings reveal direct MLL1 epigenetic control over proproliferative cell cycle genes: MLL1 inhibition represses expression of proproliferative cell cycle regulators required for DNA replication and DDR activation, thus disabling SASP expression. Strikingly, however, these effects of MLL1 inhibition on SASP gene expression do not impair OIS and, furthermore, abolish the ability of the SASP to enhance cancer cell proliferation. More broadly, MLL1 inhibition also reduces âÂÂSASP-likeâ inflammatory gene expression from cancer cells in vitro and in vivo independently of senescence. Taken together, these data demonstrate that MLL1 inhibition may be a powerful and effective strategy for inducing cancerous growth arrest through the direct epigenetic regulation of proliferation-promoting genes and the avoidance of deleterious OIS- or TIS-related tumor secretomes, which can promote both drug resistance and tumor progression. This study consists of a single replicate of RNA-seq from oncogene-induced senescent (or control) IMR90 cells in a MLL1 knockdown (or WT) background, for a total of four samples
Project description:Immunotherapies that produce durable responses in some malignancies have failed in pancreatic ductal adenocarcinoma (PDAC) due to rampant immune suppression and poor tumor immunogenicity. We and others have demonstrated that induction of the senescence-associated secretory phenotype (SASP) can be an effective approach to activate anti-tumor Natural Killer (NK) and T cell immunity. Here we found the pancreas tumor microenvironment (TME) suppresses NK and T cell surveillance following therapy-induced senescence through EZH2-mediated epigenetic repression of pro-inflammatory SASP genes. EZH2 blockade stimulated production of SASP chemokines CCL2 and CXCL9/10, leading to enhanced NK and T cell infiltration and PDAC eradication in mouse models. EZH2 activity was also associated with suppression of chemokine signaling and cytotoxic lymphocytes and reduced survival in PDAC patients. These results demonstrate that EZH2 represses of the pro-inflammatory SASP, and that EZH2 inhibition combined with senescence-inducing therapy could be a powerful means to achieve immune-mediated tumor control in PDAC.
Project description:Immunotherapies that produce durable responses in some malignancies have failed in pancreatic ductal adenocarcinoma (PDAC) due to rampant immune suppression and poor tumor immunogenicity. We and others have demonstrated that induction of the senescence-associated secretory phenotype (SASP) can be an effective approach to activate anti-tumor Natural Killer (NK) and T cell immunity. Here we found the pancreas tumor microenvironment (TME) suppresses NK and T cell surveillance following therapy-induced senescence through EZH2-mediated epigenetic repression of pro-inflammatory SASP genes. EZH2 blockade stimulated production of SASP chemokines CCL2 and CXCL9/10, leading to enhanced NK and T cell infiltration and PDAC eradication in mouse models. EZH2 activity was also associated with suppression of chemokine signaling and cytotoxic lymphocytes and reduced survival in PDAC patients. These results demonstrate that EZH2 represses of the pro-inflammatory SASP, and that EZH2 inhibition combined with senescence-inducing therapy could be a powerful means to achieve immune-mediated tumor control in PDAC.
Project description:Immunotherapies that produce durable responses in some malignancies have failed in pancreatic ductal adenocarcinoma (PDAC) due to rampant immune suppression and poor tumor immunogenicity. We and others have demonstrated that induction of the senescence-associated secretory phenotype (SASP) can be an effective approach to activate anti-tumor Natural Killer (NK) and T cell immunity. Here we found the pancreas tumor microenvironment (TME) suppresses NK and T cell surveillance following therapy-induced senescence through EZH2-mediated epigenetic repression of pro-inflammatory SASP genes. EZH2 blockade stimulated production of SASP chemokines CCL2 and CXCL9/10, leading to enhanced NK and T cell infiltration and PDAC eradication in mouse models. EZH2 activity was also associated with suppression of chemokine signaling and cytotoxic lymphocytes and reduced survival in PDAC patients. These results demonstrate that EZH2 represses of the pro-inflammatory SASP, and that EZH2 inhibition combined with senescence-inducing therapy could be a powerful means to achieve immune-mediated tumor control in PDAC.
Project description:Cellular senescence is a stable cell growth arrest that is implicated in tissue aging and cancer. Senescent cells are characterized by an upregulation of proinflammatory and immunosuppressive cytokines and chemokines, which is termed as senescence-associated secretory phenotype (SASP). NAD+ metabolism plays a critical role in both tissue aging and cancer. However, the role of NAD+ metabolism in regulating the SASP is not well understood. Here we show that nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme of the NAD+ salvage pathway, governs the strengths of proinflammatory SASP during senescence. In contrast to downregulation of NAMPT during replicative senescence, NAMPT is upregulated during oncogene-induced senescence. NAMPT selectively regulates proinflammatory, but not immunosuppressive, SASP. NAMPT is regulated by HMGA1 through a distal enhancer element during senescence. HMGA1/NAMPT/NAD+ signaling axis promotes proinflammatory SASP through enhancing glycolysis and mitochondria respiration. Mechanistically, HMGA1/NAMPT promotes proinflammatory SASP through NAD+-mediated suppression of AMPK kinase, which suppresses p53-mediated inhibition of p38MAPK to enhance NFb activity. SASP regulation by NAD+ metabolism is independent of senescence-associated cell growth arrest. An increase in NAD+ levels is sufficient to convert SASP from low to high levels during replicative senescence. Together, we conclude that NAD+ metabolism governs the strengths of proinflammatory SASP. Given the tumor promoting effects of proinflammatory SASP, our results suggest that anti-ageing dietary NAD+ augmentation should be administered with precision.
Project description:Acute Pten loss initiates prostate tumorigenesis characterized by cellular senescence response. Senescent cells secrete a variety of pro inflammatory factors in the tumor microenvironment, which can support the survival, outgrowth and migration of tumor cells. Here we examine cytokines and cytokines-related factors gene expression in Ptenpc-/- senescent and in Ptenpc-/-; Trp53pc-/- non senescent tumors. RNAseq analysis confirmed the presence of cytokines, which were specifically up- and down-regulated in Ptenpc-/- senescent tumors (“core-SASP”) we also found a number of upregulated secreted factors that were “senescence-unrelated” both present in both Ptenpc-/- and Ptenpc-/-; Trp53pc-/- tumors.
Project description:Cellular senescence is a stress or damage response that causes a permanent proliferative arrest and secretion of numerous factors with potent biological activities. This senescence-associated secretory phenotype (SASP) has been characterized largely for secreted proteins that participate in embryogenesis, wound healing, inflammation and many age-related pathologies. By contrast, lipid components of the SASP are understudied. We show that senescent cells activate the biosynthesis of several oxylipins that promote segments of the SASP and reinforce the proliferative arrest. Notably, senescent cells synthesize and accumulate an unstudied intracellular prostaglandin, 1a,1b-dihomo-15-deoxy-delta-12,14-prostaglandin J2. Released 15-deoxy-delta-12,14-prostaglandin J2 is a biomarker of senolysis in culture and in vivo. This and other prostaglandin D2-related lipids promote the senescence arrest and SASP by activating RAS signaling. These data identify an important aspect of cellular senescence and a method to detect senolysis
Project description:Cellular senescence, a stable cell growth arrest, can have dual effects in tumors, either suppressing or promoting tumor progression. The Senescence-Associated Secretory Phenotype (SASP), released by senescent cells, plays a crucial role in this dichotomy. Consequently, the clinical challenge lies in developing therapies that safely enhance senescence in cancer, promoting tumor-suppressive over tumor-promoting SASP factors. Here, we identified the Retinoic-Acid-Receptor (RAR) agonist Adapalene as an effective pro-senescence compound in prostate cancer (PCa). The reactivation of the RARs triggers a strong senescence response and a tumor-suppressive SASP. In preclinical mouse models of PCa, the combination of Adapalene and Docetaxel, promotes a tumor-suppressive SASP that activates NK cell-mediated tumor clearance more effectively than either agent alone. This approach increases the efficacy of allogenic infusion of human NK cells in mice injected with human PCa cells, suggesting an alternative therapeutic strategy to stimulate the anti-tumor immune response in "immunologically cold" tumors.