Project description:Most kidney cancers display metabolic dysfunction but how this relates to cancer progression in humans is unknown. We infused 13C-labeled nutrients during surgical tumour resection in over 80 patients with kidney cancer. Labeling from [U-13C]glucose varies across subtypes, indicating that the kidney environment alone cannot account for all metabolic reprogramming in these tumours. Compared to the adjacent kidney, clear cell renal cell carcinomas (ccRCC) display suppressed labelling of tricarboxylic acid (TCA) cycle intermediates in vivo and in organotypic cultures ex vivo, indicating that suppressed labeling is tissue intrinsic. Infusions of [1,2-13C]acetate and [U-13C]glutamine in patients, coupled with measurements of respiration in mitochondria isolated from kidneys and tumours, reveal electron transport chain (ETC) defects in ccRCC. However, ccRCC metastases unexpectedly have enhanced TCA cycle labeling compared to primary ccRCCs, indicating a divergent metabolic program during metastasis in patients. In mice, stimulating respiration or NADH recycling in kidney cancer cells is sufficient to promote metastasis, while inhibiting ETC complex I decreases metastasis. These findings indicate that metabolic properties and liabilities evolve during kidney cancer progression in humans, and that mitochondrial function is limiting for metastasis but not for growth at the original site.
Project description:Kidney is a vital organ responsible for homeostasis in the body. To retard kidney aging is of great importance for maintaining body health. Whereas the therapeutic strategies targeting against kidney aging are not elucidated. Recent studies show mitochondrial dysfunction is critical for renal tubular cell senescence and kidney aging, however, the underlying mechanisms of mitochondrial dysfunction in kidney aging have not been demonstrated. Herein, we found calcium overload, and the mitochondrial calcium uniporter (MCU) was induced in renal tubular cells and aged kidney. To activate MCU not only triggered mitochondrial calcium overload, but also induced reactive oxygen species (ROS) production and cellular senescence and age-related kidney fibrosis. Inversely, to block MCU or chelate calcium diminished ROS generation, restored mitochondrial homeostasis, and retarded cell senescence and protected against kidney aging. These results demonstrate MCU plays a key role in promote renal tubular cell senescence, which provides a new insight on the therapeutic strategy for fighting against kidney aging.
Project description:Mitochondrial metabolism plays a central role in promoting cancer growth and metastatic progression. The transition between a hyperfused and fragmented mitochondrial network is termed mitochondrial dynamics and is important for many mitochondria-associated functions; however, little is known regarding how this process influences metastasis. Here, we show that breast cancer cells with low metastatic potential exhibit a more fused mitochondrial network compared to highly metastatic breast cancer cells. To examine whether a fused mitochondrial network could impair metastasis, we inhibited mitochondrial fission in metastatic breast cancer cells by individual genetic deletion of three key regulators of mitochondrial fission (Drp1, Fis1 and Mff) or pharmacological intervention using leflunomide, an anti-rheumatic drug. These cells displayed a fused mitochondrial network and limited survival under anoikis conditions, consistent with mitochondrial fusion limiting metastasis. Transcriptomics and metabolomics analyses revealed that mitochondrial fusion causes significant alterations in metabolic pathways and processes related to cell adhesion. Functional bioenergetics assays demonstrated that mitochondrial fusion limited the mitochondrial capacity of cancer cells. Mitochondrial fusion in breast cancer cells had no significant effect on primary tumor growth but almost completely ablated lung metastasis in vivo. Furthermore, the transcriptomics signature associated with enhanced mitochondrial fusion correlated with improved survival in patients with breast cancer. Overall, our findings highlight mitochondrial fusion as a therapeutic opportunity for breast cancer.
Project description:This SuperSeries is composed of the following subset Series: GSE39356: MiR-374a Promotes Epithelial-Mesenchymal Transition (EMT) and Metastasis of Breast Cancer (mRNA dataset) GSE39358: MiR-374a Promotes Epithelial-Mesenchymal Transition (EMT) and Metastasis of Breast Cancer (miRNA dataset) Refer to individual Series
Project description:Reversible acetylation of mitochondrial proteins is a regulatory mechanism central to adaptive metabolic responses. Yet, how such functionally relevant protein acetylation is achieved remains unexplored. Here, we reveal an unprecedented role of the MYST family lysine acetyltransferase MOF in energy metabolism via mitochondrial protein acetylation. Loss of MOF-KANSL complex members led to mitochondrial defects including fragmentation, reduced cristae density and impaired mitochondrial electron transport chain (mtETC) complex IV (CIV) integrity in primary mouse embryonic fibroblasts. We demonstrate COX17, a CIV assembly factor, as a bona fide acetylation target of MOF. Loss of COX17 or expression of its non-acetylatable mutant phenocopied the mitochondrial defects observed upon MOF depletion. The acetylation-mimetic COX17 rescues these defects and maintains CIV activity even in the absence of MOF, suggesting an activatory role of mtETC protein acetylation. Fibroblasts from MOF syndrome patients with intellectual disability also revealed respiratory defects that could be restored by alternative oxidase, acetylation-mimetic COX17 or mitochondrially targeted MOF. Overall, our findings highlight the critical role of MOF-KANSL complex in mitochondrial physiology and provide new insights into MOF syndrome.
Project description:Vascular pericytes, an important cellular component, in the tumor microenvironment, are often associated with tumor vasculatures and their functions in cancer invasion and metastasis are poorly understood. Here we show that PDGF-BB induces pericyte fibroblast transition (designated as PFT), which significantly contributes to tumor invasion and metastasis. Gain- and loss-of-function experiments demonstrate that the PDGF-BB-PDGFRβ signaling promotes PFT in vitro and in in vivo tumors. Genome-wide expression analysis indicates that PDGF-BB-activated pericytes acquire mesenchymal progenitor features. Pharmacological inhibition and genetic deletion of PDGFRβ ablate the PDGF-BB-induced PFT. Genetic tracing of pericytes with two independent mouse strains, i.e., TN-AP-CreERT2:R26R-tdTomato and NG2:R26R-tdTomato, shows that PFT cells gains stromal fibroblast and myofibroblast markers in tumors. Importantly, co-implantation of PFT cells with less-invasive tumor cells in mice markedly promotes tumor dissemination and invasion, leading to an increased number of circulating tumor cells (CTCs) and metastasis. Our findings reveal a novel mechanism of vascular pericytes in PDGF-BB-promoted cancer invasion and metastasis by inducing PFT and thus targeting PFT may offer a new treatment option of cancer metastasis. Pericytes were isolated and treated with PDGF-BB or control for 1 or 5 days