Research into cancer metabolomics: towards a clinical metamorphosis

The acknowledgement that metabolic reprogramming is a central feature of cancer has generated high expectations for major advances in both diagnosis and treatment of malignancies through addressing metabolism. These have so far only been partially fulfilled, with only a few clinical applications. However, numerous diagnostic and therapeutic compounds are currently being evaluated in either clinical trials or pre-clinical models and new discoveries of alterations in metabolic genes indicate future prognostic or other applicable relevance. Altogether, these metabolic approaches now stand alongside other available measures providing hopes for the prospects of metabolomics in the clinic. Here we present a comprehensive overview of both ongoing and emerging clinical, pre-clinical and technical strategies for exploiting unique tumour metabolic traits, highlighting the current promises and anticipations of research in the field

Succinate Dehydrogenase Supports Metabolic Repurposing of Mitochondria to Drive Inflammatory Macrophages.

Activated macrophages undergo metabolic reprogramming, which drives their pro-inflammatory phenotype, but the mechanistic basis for this remains obscure. Here, we demonstrate that upon lipopolysaccharide (LPS) stimulation, macrophages shift from producing ATP by oxidative phosphorylation to glycolysis while also increasing succinate levels. We show that increased mitochondrial oxidation of succinate via succinate dehydrogenase (SDH) and an elevation of mitochondrial membrane potential combine to drive mitochondrial reactive oxygen species (ROS) production. RNA sequencing reveals that this combination induces a pro-inflammatory gene expression profile, while an inhibitor of succinate oxidation, dimethyl malonate (DMM), promotes an anti-inflammatory outcome. Blocking ROS production with rotenone by uncoupling mitochondria or by expressing the alternative oxidase (AOX) inhibits this inflammatory phenotype, with AOX protecting mice from LPS lethality. The metabolic alterations that occur upon activation of macrophages therefore repurpose mitochondria from ATP synthesis to ROS production in order to promote a pro-inflammatory state

RUNX1 is a driver of renal cell carcinoma correlating with clinical outcome

The recurring association of specific genetic lesions with particular types of cancer is a fascinating, and largely unexplained area of cancer biology. This is particularly true of clear cell renal cell carcinoma (ccRCC) where although key mutations such as loss of VHL is an almost ubiquitous finding, there remains a conspicuous lack of targetable genetic drivers. In this study, we have identified a previously unknown pro-tumorigenic role for the RUNX genes in this disease setting. Analysis of patient tumor biopsies together with loss of function studies in preclinical models established the importance of RUNX1 and RUNX2 in ccRCC. Patients with high RUNX1 (and RUNX2) expression exhibited significantly poorer clinical survival compared to patients with low expression. This was functionally relevant as deletion of RUNX1 in ccRCC cell lines reduced tumor cell growth and viability in vitro and in vivo. Transcriptional profiling of RUNX1-CRISPR-deleted cells revealed a gene signature dominated by extracellular matrix remodelling, notably affecting STMN3, SERPINH1, and EPHRIN signaling. Finally, RUNX1 deletion in a genetic mouse model of kidney cancer improved overall survival and reduced tumor cell proliferation. In summary, these data attest to the validity of targeting a RUNX1-transcriptional program in ccRCC. [Abstract copyright: Copyright ©2020, American Association for Cancer Research.

Cancer-associated fibroblasts require proline synthesis by PYCR1 for the deposition of pro-tumorigenic extracellular matrix

Elevated production of collagen-rich extracellular matrix is a hallmark of cancer-associated fibroblasts (CAFs) and a central driver of cancer aggressiveness. Here we find that proline, a highly abundant amino acid in collagen proteins, is newly synthesized from glutamine in CAFs to make tumour collagen in breast cancer xenografts. PYCR1 is a key enzyme for proline synthesis and highly expressed in the stroma of breast cancer patients and in CAFs. Reducing PYCR1 levels in CAFs is sufficient to reduce tumour collagen production, tumour growth and metastatic spread in vivo and cancer cell proliferation in vitro. Both collagen and glutamine-derived proline synthesis in CAFs are epigenetically upregulated by increased pyruvate dehydrogenase-derived acetyl-CoA levels. PYCR1 is a cancer cell vulnerability and potential target for therapy; therefore, our work provides evidence that targeting PYCR1 may have the additional benefit of halting the production of a pro-tumorigenic extracellular matrix. Our work unveils new roles for CAF metabolism to support pro-tumorigenic collagen production

Multi-omics and pathway analysis identify potential roles for tumour n-acetyl aspartate accumulation in murine models of castration resistant prostate cancer

Castration-resistant prostate cancer (CRPC) is incurable and remains a significant worldwide challenge (Oakes and Papa, 2015). Matched untargeted multi-level omic datasets may reveal biological changes driving CRPC, identifying novel biomarkers and/or therapeutic targets. Untargeted RNA sequencing, proteomics, and metabolomics was performed on xenografts derived from three independent sets of hormone naïve and matched CRPC human cell line models of local, lymph node and bone metastasis grown as murine orthografts. Collectively, we tested the feasibility of muti-omics analysis on models of CRPC in revealing pathways of interest for future validation investigation. Untargeted metabolomics revealed NAA and NAAG commonly accumulating in CRPC across three independent models and proteomics showed upregulation of related enzymes, namely N-Acetylated Alpha-Linked Acidic Dipeptidases (FOLH1/NAALADL2). Based on pathway analysis integrating multiple omic levels we hypothesise that increased NAA in CRPC may be due to upregulation of NAAG hydrolysis via NAALADLases providing a pool of Acetyl Co-A for upregulated sphingolipid metabolism and a pool of glutamate and aspartate for nucleotide synthesis during tumour growth

Author correction : Cancer-associated fibroblasts require proline synthesis by PYCR1 for the deposition of pro-tumorigenic extracellular matrix

Correction to: Nature Metabolism https://doi.org/10.1038/s42255-022-00582-0, published online 27 June 2022 In the version of this article initially published, the surname of the third author, Carla Riera-Domingo, was misspelled as Riero-Domingo. The error has been corrected in the HTML and PDF versions of the article

Cancer-associated fibroblasts require proline synthesis by PYCR1 for the deposition of pro-tumorigenic extracellular matrix

Elevated production of collagen-rich extracellular matrix is a hallmark of cancer-associated fibroblasts (CAFs) and a central driver of cancer aggressiveness. Here we find that proline, a highly abundant amino acid in collagen proteins, is newly synthesized from glutamine in CAFs to make tumour collagen in breast cancer xenografts. PYCR1 is a key enzyme for proline synthesis and highly expressed in the stroma of breast cancer patients and in CAFs. Reducing PYCR1 levels in CAFs is sufficient to reduce tumour collagen production, tumour growth and metastatic spread in vivo and cancer cell proliferation in vitro. Both collagen and glutamine-derived proline synthesis in CAFs are epigenetically upregulated by increased pyruvate dehydrogenase-derived acetyl-CoA levels. PYCR1 is a cancer cell vulnerability and potential target for therapy; therefore, our work provides evidence that targeting PYCR1 may have the additional benefit of halting the production of a pro-tumorigenic extracellular matrix. Our work unveils new roles for CAF metabolism to support pro-tumorigenic collagen production

Senescence-associated reprogramming promotes cancer stemness

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