Mitochondrial Mutations and Metabolic Adaptation in Pancreatic Cancer
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PROVIDER: PRJEB18798 | ENA |
REPOSITORIES: ENA
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Project description:BACKGROUND:Pancreatic cancer has a five-year survival rate of ~8%, with characteristic molecular heterogeneity and restricted treatment options. Targeting metabolism has emerged as a potentially effective therapeutic strategy for cancers such as pancreatic cancer, which are driven by genetic alterations that are not tractable drug targets. Although somatic mitochondrial genome (mtDNA) mutations have been observed in various tumors types, understanding of metabolic genotype-phenotype relationships is limited. METHODS:We deployed an integrated approach combining genomics, metabolomics, and phenotypic analysis on a unique cohort of patient-derived pancreatic cancer cell lines (PDCLs). Genome analysis was performed via targeted sequencing of the mitochondrial genome (mtDNA) and nuclear genes encoding mitochondrial components and metabolic genes. Phenotypic characterization of PDCLs included measurement of cellular oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) using a Seahorse XF extracellular flux analyser, targeted metabolomics and pathway profiling, and radiolabelled glutamine tracing. RESULTS:We identified 24 somatic mutations in the mtDNA of 12 patient-derived pancreatic cancer cell lines (PDCLs). A further 18 mutations were identified in a targeted study of ~1000 nuclear genes important for mitochondrial function and metabolism. Comparison with reference datasets indicated a strong selection bias for non-synonymous mutants with predicted functional effects. Phenotypic analysis showed metabolic changes consistent with mitochondrial dysfunction, including reduced oxygen consumption and increased glycolysis. Metabolomics and radiolabeled substrate tracing indicated the initiation of reductive glutamine metabolism and lipid synthesis in tumours. CONCLUSIONS:The heterogeneous genomic landscape of pancreatic tumours may converge on a common metabolic phenotype, with individual tumours adapting to increased anabolic demands via different genetic mechanisms. Targeting resulting metabolic phenotypes may be a productive therapeutic strategy.
| S-EPMC5282905 | biostudies-literature
Project description:Reduced estrogen action is associated with obesity and insulin resistance. However, the cell and tissue-specific actions of estradiol in maintaining metabolic health remain inadequately understood especially in men. We observed that skeletal muscle ESR1/Esr1 (encodes estrogen receptor a), including expression of specific ESR1 variants is positively correlated with insulin sensitivity and metabolic health in humans and mice. Because skeletal muscle is a primary tissue involved in oxidative metabolism and insulin sensitivity, we generated muscle-selective Esr1 loss- and gain of-expression mouse models. We determined that Esr1 links mitochondrial DNA replication and cristae-nucleoid architecture with metabolic function and insulin action in skeletal muscle of male mice. Overexpression of human ERα in muscle protected male mice from diet-induced disruption of metabolic health and enhanced mitochondrial adaptation to exercise training intervention. Our findings indicate that muscle expression of Esr1 is critical for the maintenance of mitochondrial function and metabolic health in males, and that tissue-selective activation of ERα can be leveraged to combat metabolic-related diseases in both sexes.
2024-10-30 | GSE280715 | GEO
Project description:Fibroblast growth factor 21 (FGF21) is a key metabolic regulator which was recently discovered as stress-induced myokine and common denominator of muscle mitochondrial disease. However, its precise function and pathophysiological relevance remains unknown. Here we demonstrate that white adipose tissue (WAT) is the major target of muscle mitochondrial stress-induced FGF21. Strikingly, substantial browning and metabolic remodeling of subcutaneous WAT, together with the reduction of circulating triglycerides and cholesterol are fully FGF21 dependent. Unexpectedly and in contrast to prior expectations, we found a negligible role of FGF21 in muscle stress-related improved glycemic control, obesity resistance and hepatic lipid homeostasis. Furthermore, we show that the protective muscle mitohormesis and metabolic stress adaptation does not require FGF21 action. Taken together, our data imply that although FGF21 drives WAT remodeling, this effect and FGF21 as stress hormone per se may not be essential for the adaptive response under muscle mitochondrial stress conditions. Wildtype male mice and FGF21-knockout male mice, together with muscle specific UCP1-transgenic male animals, and double cross of FGF21-KO with UCP1-Tg male mice, were kept on a standardized low fat diet for 40 weeks. After sacrifice, subcutaneous white adipose tisseu (scWAT) was rapidly removed, weighed, and snap frozen in liquid nitrogen and used for RNA isolation and whole genome gene expression microarray hybridisation using Agilent arrays.
2016-01-07 | E-GEOD-71749 | biostudies-arrayexpress
Project description:Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal human cancers. It thrives in a nutrient-poor environment; however, the mechanisms by which PDAC cells undergo metabolic reprogramming to adapt and survive in metabolic stress are still poorly understood. Here, we show that microRNA-135 is significantly increased in PDAC patient samples compared to adjacent normal tissue and represses aerobic glycolysis. Mechanistically, we found that miR-135 accumulates specifically in response to glutamine deprivation and requires ROS-dependent activation of mutant p53, which directly promotes miR-135 expression. Functionally, we found miR-135 targets phosphofructokinase-1 (PFK1) and inhibits aerobic glycolysis, thereby promoting the utilization of glucose to support the tricarboxylic acid (TCA) cycle. Consistently, miR-135 deficient PDAC cells preferentially use glutamine carbon to replenish the TCA cycle, and miR-135 silencing sensitizes PDAC cells to glutamine deprivation and represses tumour growth in vivo. Consistent with these findings, patient pancreatic cancer tissue displays decreased PFK1 level compared to adjacent normal tissue. Together, these results identify a mechanism used by PDAC cells to survive the nutrient-poor tumour microenvironment, and also provide insight regarding the role of mutant p53 and miRNA in pancreatic cancer cell adaptation to metabolic stresses.
2019-02-27 | GSE125538 | GEO
Project description:Using Caenorhabditis elegans to investigate environmental cues-induced mitochondrial dysfunction, we found that exposure to electron transport chain (ETC) inhibitors at the parental generation initiates the transmission of heritable information to descendants and make descendants stress-adaptive. This mitochondrial stress adaptation phenotype can persist for at least three generations. Animals lacking histone H3K4me3 chromatin modifiers, or the methyltransferase of N6-methyldeoxyadenosine (6mA), lose the ability to initiate stress adaptation in progeny. H3K4me3 plays a role upstream of 6mA, while both mark promoter regions of mitochondrial unfolded protein response (UPR mt ) genes and activate the UPR mt pathway to alleviate mitochondrial damage.
2017-07-26 | GSE85835 | GEO
Project description:Exercise is a fundamental component of human health that is associated with greater life expectancy and reduced risk of chronic diseases. While the beneficial effects of endurance exercise on human health are well established, the molecular mechanisms responsible for these observations remain unclear. Endurance exercise reduces the accumulation of mitochondrial DNA (mtDNA) mutations, alleviates multisystem pathology, and increases the lifespan of the mtDNA mutator mouse model of aging, in which the proof-reading capacity of mitochondrial polymerase gamma (POLG1) is deficient. Clearly, exercise recruited a POLG1-independent mtDNA repair pathway to induce these adaptations, a novel finding as POLG1 is canonically considered to be the sole mtDNA repair enzyme. Here we investigate the identity of this pathway, and show that endurance exercise prevents mitochondrial oxidative damage, attenuates telomere erosion, and mitigates cellular senescence and apoptosis in mtDNA mutator mice. Unexpectedly, we observe translocation of tumour suppressor protein p53 to mitochondria in response to endurance exercise that facilitates mtDNA mutation repair. Indeed, endurance exercise failed to prevent mtDNA mutations, induce mitochondrial biogenesis, preserve mitochondrial morphology, reverse sarcopenia, and mitigate premature mortality in mtDNA mutator mice with muscle-specific deletion of p53. Our data establish an exciting new role for p53 in exercise-mediated maintenance of the mtDNA genome, and presents mitochondrially-targeted p53 as a novel therapeutic modality for aging-associated diseases of mitochondrial etiology. Microarray analysis of gene expression from skeletal muscle (quadriceps femoris) from Mus musculus. N=23 samples per treatment were analysed for whole transcriptiome gene expression profile using NimbleGen Arrays. The treatment groups included wild-type C57Bl/6J mice as the control group, then two treatment groups which both contained homozygous knock-in mtDNA mutator mice (PolG; PolgAD257A/D257A). Once group of these heterozygous knock out mice received regular endurance exercise sessions while the other group remained sedentraty for 6 months. The control group specimens were wild-type litter mates to the transgenic knockout mice.
2015-12-11 | E-GEOD-75869 | biostudies-arrayexpress
Project description:The complex life cycle of the malaria parasite Plasmodium falciparum involves many different environments. Additionally, the parasite encounters fluctuating conditions within the same niche. For example, in the human blood parasites face variability in the host’s immune response, presence of antimalarial drugs or availability of nutrients, among others. Bet-hedging adaptive strategies, which involve population heterogeneity that precedes changes in the environment, play an important role in the adaptation of P. falciparum asexual blood stages to fluctuations in their environment. This is linked to clonally variant expression, regulated at the epigenetic level, of a large number of malarial genes. However, currently there are very few examples of fluctuation conditions to which adaptation by changes in the expression of clonally variant genes has been established. Here we studied the adaptation of P. falciparum cultures to grow in the absence of an external source of lipids. In three independent adaptation experiments, cultures were able to adapt to grow without lipids in the culture medium and this was linked to acquisition of deletions or non-sense mutations in the pfndh2 gene, a component of the mitochondrial electron transport chain. In contrast, full transcriptome analysis did not provide evidence for a role for bet-hedging strategies in the adaptation of parasites to grow in lipid-free medium. Therefore, adaptation to this type of stress involved metabolic rewiring achieved by inactivation of a gene involved the mitochondrial respiratory chains.
2022-09-01 | GSE183526 | GEO
Project description:Fibroblast growth factor 21 (FGF21) is a key metabolic regulator which was recently discovered as stress-induced myokine and common denominator of muscle mitochondrial disease. However, its precise function and pathophysiological relevance remains unknown. Here we demonstrate that white adipose tissue (WAT) is the major target of muscle mitochondrial stress-induced FGF21. Strikingly, substantial browning and metabolic remodeling of subcutaneous WAT, together with the reduction of circulating triglycerides and cholesterol are fully FGF21 dependent. Unexpectedly and in contrast to prior expectations, we found a negligible role of FGF21 in muscle stress-related improved glycemic control, obesity resistance and hepatic lipid homeostasis. Furthermore, we show that the protective muscle mitohormesis and metabolic stress adaptation does not require FGF21 action. Taken together, our data imply that although FGF21 drives WAT remodeling, this effect and FGF21 as stress hormone per se may not be essential for the adaptive response under muscle mitochondrial stress conditions.
2016-01-07 | GSE71749 | GEO
Project description:Mutations in the mitochondrial DNA (mtDNA) have been proposed to be essential for metabolic adaptation, and because metabolism is intrinsically associated with multiple disease states, including obesity, we hypothesized that changes in the mtDNA would significantly influence adiposity and gene expression in response to diet. To test these predictions we used Mitochondrial-Nuclear eXchange mice, which have nuclear and mitochondrial genomes that have been exchanged from different M. musculus strains.
2018-09-12 | GSE86826 | GEO
Project description:OxyR is a convergent target for mutations acquired during adaptation to oxidative stress-prone metabolic states
| PRJNA559161 | ENA