Project description:Pancreatic ductal adenocarcinoma (PDAC) thrives in a nutrient-deprived microenvironment, making it particularly susceptible to treatments that interfere with cancer metabolism. For example, PDAC utilizes and is dependent on high levels of autophagy and other lysosomal processes. Although targeting these pathways has shown potential in pre-clinical studies, progress has been hampered by the challenge of identifying and characterizing favorable targets for drug development. Here, we characterize PIKfyve, a lipid kinase integral to lysosomal functioning as a novel and targetable vulnerability in PDAC. Through comprehensive metabolic analyses we find that PIKfyve inhibition obligates PDAC to upregulate de novo lipid synthesis, a relationship previously undescribed. PIKfyve inhibition triggers a distinct lipogenic gene expression and metabolic program, creating a dependency on de novo lipid metabolism pathways, including genes such as FASN and ACACA. These results suggest that targeting PIKfyve disrupts lysosome-dependent lipid metabolism in PDAC and may be a favorable metabolic target for therapeutic development. Further, this data suggests that one could take advantage of this synthetic dependency by co-targeting PIKfyve and FASN or ACACA as a therapeutic strategy.
Project description:Pancreatic ductal adenocarcinoma (PDAC) thrives in a nutrient-deprived microenvironment, making it particularly susceptible to treatments that interfere with cancer metabolism. For example, PDAC utilizes and is dependent on high levels of autophagy and other lysosomal processes. Although targeting these pathways has shown potential in pre-clinical studies, progress has been hampered by the challenge of identifying and characterizing favorable targets for drug development. Here, we characterize PIKfyve, a lipid kinase integral to lysosomal functioning as a novel and targetable vulnerability in PDAC. Through comprehensive metabolic analyses we find that PIKfyve inhibition obligates PDAC to upregulate de novo lipid synthesis, a relationship previously undescribed. PIKfyve inhibition triggers a distinct lipogenic gene expression and metabolic program, creating a dependency on de novo lipid metabolism pathways, including genes such as FASN and ACACA. These results suggest that targeting PIKfyve disrupts lysosome-dependent lipid metabolism in PDAC and may be a favorable metabolic target for therapeutic development. Further, this data suggests that one could take advantage of this synthetic dependency by co-targeting PIKfyve and FASN or ACACA as a therapeutic strategy.
Project description:Pathways that stimulate β-cell regeneration remain of great clinical interest, yet effective therapeutic avenues that promote survival or reconstitution of β-cell mass remain elusive. Utilizing a mouse model with inducible β-cell apoptosis followed by adiponectin-mediated regeneration, we aimed to identify key molecules boosting β-cell viability. Within the regenerating pancreatic islets, we examined changes within the transcriptome, and observed an extensive upregulation of genes encoding proteins involved in lipid transport and metabolism. The most prominent targets were further confirmed by quantitative PCR and immunofluorescence. Among the upstream regulators predicted by pathway analysis of the transcriptome, we detected enhanced levels of two key transcription factors, HNF4α and PPARα. Enhanced leptin levels in circulation may also contribute to the anti-lipotoxic program in islets. In summary, our data suggest that improving local lipid metabolism as an important anti-lipotoxic phenomenon to boost β-cell regeneration, primarily mediated by adiponectin’s action on the β-cells directly as well as on the adipocyte. RNA profiles of pancreatic islets isolated from PANIC-ATTAT mice crossed with adiponectin wild-type (P-Adn+/+) or the overexpressing transgene (P-AdnTg/+) at 5 weeks after initial dimerizer administration.
Project description:Lactate is abundant in the tumor environment as the secreted product of fermentative cells. In prostate cancer (PCa), cancer-associated fibroblasts are the major contributors and this secreted lactate is uptaken by cancer cells to sustain their mitochondrial metabolism. However, how lactate controls the metabolic and transcriptional regulation in tumors is far to be elucidated. Here, we identify an innovative lactate-driven mechanism able to increase the expression of genes involved in lipid metabolism in PCa cells. This regulation enhances intracellular lipid accumulation in lipid droplets (LDs) and provides acetyl moieties for histone acetylation, establishing a regulatory loop between metabolites and epigenetic control. Interestingly, inhibition of this loop by targeting bromodomains histone acetylation readers suppresses the expression of perilipin-2 (PLIN2), a crucial component of LDs, disrupting the lactate-dependent lipid metabolic rewiring. Since this metabolic-epigenetic regulatory loop sustains PCa metastatic potential, its targeting is of clinical relevance as demonstrated by the inhibition of PCa invasive potential in vivo. Overall, our findings show that lactate has both a metabolic and an epigenetic role in promoting PCa progression.
Project description:Pathways that stimulate β-cell regeneration remain of great clinical interest, yet effective therapeutic avenues that promote survival or reconstitution of β-cell mass remain elusive. Utilizing a mouse model with inducible β-cell apoptosis followed by adiponectin-mediated regeneration, we aimed to identify key molecules boosting β-cell viability. Within the regenerating pancreatic islets, we examined changes within the transcriptome, and observed an extensive upregulation of genes encoding proteins involved in lipid transport and metabolism. The most prominent targets were further confirmed by quantitative PCR and immunofluorescence. Among the upstream regulators predicted by pathway analysis of the transcriptome, we detected enhanced levels of two key transcription factors, HNF4α and PPARα. Enhanced leptin levels in circulation may also contribute to the anti-lipotoxic program in islets. In summary, our data suggest that improving local lipid metabolism as an important anti-lipotoxic phenomenon to boost β-cell regeneration, primarily mediated by adiponectin’s action on the β-cells directly as well as on the adipocyte.