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Vander Heiden, M. G.

Publications and source records attributed to Vander Heiden, M. G..

36 records · Page 2Linked to original sources

Screening in serum-derived medium reveals differential response to compounds targeting metabolism

INTRODUCTION INTRODUCTION RESULTS DISCUSSION KEY RESOURCES TABLE CONTACT FOR REAGENT AND... EXPERIMENTAL MODEL AND SUBJECT... METHOD DETAILS QUANTIFICATION AND STATISTICAL... Data resources DATA AND SOFTWARE AVAILABILITY AUTHOR CONTRIBUTIONS DECLARATION OF INTERESTS REFERENCES Studies of cancer cells in standard culture conditions have long been used as a tractable tool for drug discovery. Cell culture provides unparalleled experimental flexibility, scalability, and low cost to identify and understand the response to cancer therapeutics; however, drug responses in culture are not always predictive of drug response in animal models or in patients1 ...

cancer biology↗

A CRISPRi/a screening platform to study cellular nutrient transport in diverse microenvironments

Blocking the import of nutrients essential for cancer cell proliferation represents a therapeutic opportunity, but it is unclear which transporters to target. Here, we report a CRISPRi/a screening platform to systematically interrogate the contribution of specific nutrient transporters to support cancer cell proliferation in environments ranging from standard culture media to tumor models. We applied this platform to identify the transporters of amino acids in leukemia cells and found that amino acid transport is characterized by high bidirectional flux that is dependent on the composition of the microenvironment. While investigating the role of transporters in cystine starved cells, we uncovered a novel role for serotonin uptake in preventing ferroptosis. Finally, we identified transporters essential for cell proliferation in subcutaneous tumors and found that levels of glucose and amino acids can restrain proliferation in that environment. This study provides a framework for the systematic identification of critical cellular nutrient transporters, characterizing the function of such transporters, and studying how the tumor microenvironment impacts cancer metabolism.

cancer biology↗

Cancer tissue of origin constrains the growth and metabolism of metastases

Metastases arise from a subset of cancer cells that disseminate from the primary tumor; however, the factors that contribute to proliferation of cancer cells in a secondary site are incompletely understood. The ability of cancer cells to thrive in a new tissue site is influenced by genetic and epigenetic changes that are important for disease initiation and progression, but these factors alone do not predict if and where cancers metastasize. Specific cancer types metastasize to consistent subsets of tissues, suggesting that factors associated with the primary tumor influence the tissue environments where cancers can grow. Using pancreatic cancer as a model, we find that primary and metastatic tumors share many metabolic similarities and that the tumor initiating capacity and proliferation of both primary- and metastasis-derived cells is favored in the primary site relative to the metastatic site. Moreover, propagating lung or liver metastatic cells in vivo to enrich for tumor cells adapted to grow in the lung or the liver does not enhance their relative ability to form large tumors in those sites, change their preference to grow in the primary site, nor stably alter some aspects of their metabolism relative to primary tumors. We also analyzed primary liver and lung cancer cells and find that these cells also exhibit a preference to grow in their primary site relative to metastatic sites. Together, these data suggest that the cancer tissue-of-origin influences the metabolism of both primary and metastatic tumors and may impact whether cancer cells can thrive in a metastatic site.

cancer biology↗

Nucleotide depletion promotes cell fate transitions by inducing DNA replication stress

Control of cellular identity requires coordination of developmental programs with environmental factors such as nutrient availability, suggesting that modulating aspects of metabolism could alter cell state along differentiation trajectories. Here we find that nucleotide depletion and DNA replication stress are common drivers of cell state progression across a variety of normal and transformed hematopoietic systems. DNA replication stress-induced cell state transitions begin during S phase and are independent of ATR/ATM checkpoint signaling, double-stranded DNA break formation, and changes in cell cycle length. In systems where differentiation is blocked by oncogenic transcription factor expression, replication stress leads to increased activity at primed regulatory loci and expression of lineage-appropriate maturation genes while progenitor TF activity is still present. Altering the baseline cell state by manipulating the cohort of transcription factors expressed redirects the effect of replication stress towards induction of a different set of lineage-specific genes. The ability of replication stress to selectively activate primed maturation programs across different cellular contexts suggests a general mechanism by which metabolism can promote lineage-appropriate and potentially therapeutically relevant cell state transitions.

cancer biology↗

Ablative radiotherapy improves survival in autochthonous cancer mouse models

Genetically engineered mouse models (GEMMs) of cancer are powerful tools to study mechanisms of disease progression and therapy response, yet little is known about how these models respond to multimodality therapy used for curative intent in patients. Radiation therapy (RT) is frequently used to treat localized cancers with curative intent, delay progression of oligometastases, and palliate symptoms of metastatic disease. RT can be combined with surgery, systemic therapy, and/or immunotherapy for definitive treatment of solid tumors. Here we report the development, testing, and validation of a murine platform that faithfully emulates human stereotactic ablative radiotherapy (SABR). We demonstrate that SABR regimens used in clinical practice can be effectively delivered in mouse models and establish the intestinal tract as the dose limiting organ for abdominopelvic radiation with notable, but transient, lymphodepletion. SABR alters tumor stroma and immune environment, improves survival in GEMMs of primary prostate and colorectal cancer, and synergizes with androgen deprivation in prostate cancer. While SABR is capable of fully ablating xenografts it is unable to completely eradicate disease in GEMMs. These data show that some GEMMs are resistant to curative therapy suggesting the existence of treatment-resistant persister cells in these models.

cancer biology↗

Nucleotide imbalance decouples cell growth from cell proliferation

Nucleotide metabolism supports RNA synthesis and DNA replication to enable cell growth and division. Nucleotide depletion can accordingly inhibit cell growth and proliferation, but how cells sense and respond to changes in the relative levels of individual nucleotides is unclear. Moreover, the nucleotide requirement for biomass production changes over the course of the cell cycle, and how cells coordinate differential nucleotide demands with cell cycle progression is also not well understood. Here we find that excess levels of individual nucleotides can inhibit proliferation by disrupting the relative levels of nucleotide bases needed for DNA replication. The resulting purine and pyrimidine imbalances are not sensed by canonical growth regulatory pathways, causing aberrant biomass production and excessive cell growth despite inhibited proliferation. Instead, cells rely on replication stress signaling to survive during, and recover from, nucleotide imbalance during S phase. In fact, replication stress signaling is activated during unperturbed S phases and promotes nucleotide availability to support DNA replication. Together, these data reveal that imbalanced nucleotide levels are not detected until S phase, rendering cells reliant on replication stress signaling to cope with this metabolic problem, and disrupting the coordination of cell growth and division.

cell biology↗

Protein-Metabolite Interactomics Reveals Novel Regulation of Carbohydrate Metabolism

Metabolism is highly interconnected and also has profound effects on other cellular processes. However, the interactions between metabolites and proteins that mediate this connectivity are frequently low affinity and difficult to discover, hampering our understanding of this important area of cellular biochemistry. Therefore, we developed the MIDAS platform, which can identify protein-metabolite interactions with great sensitivity. We analyzed 33 enzymes from central carbon metabolism and identified 830 protein-metabolite interactions that were mostly novel, but also included known regulators, substrates, products and their analogs. We validated previously unknown interactions, including two atomic-resolution structures of novel protein-metabolite complexes. We also found that both ATP and long-chain fatty acyl-CoAs inhibit lactate dehydrogenase A (LDHA), but not LDHB, at physiological concentrations in vitro. Treating cells with long-chain fatty acids caused a loss of pyruvate/lactate interconversion, but only in cells reliant on LDHA. We propose that these regulatory mechanisms are part of the metabolic connectivity that enables survival in an ever-changing nutrient environment, and that MIDAS enables a broader and deeper understanding of that network.

biochemistry↗

Pyruvate kinase M1 suppresses development and progression of prostate adenocarcinoma

Most cancers, including prostate cancers, express the M2 splice isoform of pyruvate kinase (Pkm2). This isoform can promote anabolic metabolism to support cell proliferation; however, Pkm2 expression is dispensable for many cancers in vivo. Pyruvate kinase M1 (Pkm1) isoform expression is restricted to relatively few tissues and has been reported to promote growth of select tumors, but the role of PKM1 in cancer has been less studied. Pkm1 is expressed in normal prostate tissue; thus, to test how differential pyruvate kinase isoform expression affects cancer initiation and progression we generated mice harboring a conditional allele of Pkm1 and crossed this allele, as well as a Pkm2 conditional allele, to a Pten loss-driven prostate cancer model. We found that Pkm1 loss leads to Pkm2 expression and accelerates prostate cancer, while deletion of Pkm2 leads to increased Pkm1 expression and suppresses cancer. Consistent with these data, a small molecule pyruvate kinase activator that mimics a PKM1-like state suppresses progression of established prostate tumors. PKM2 expression is retained in most human prostate cancers, arguing that pharmacological PKM2 activation may be beneficial for some prostate cancer patients.

cancer biology↗

Interactions with stromal cells promote a more oxidized cancer cell redox state in pancreatic tumors

Access to electron acceptors supports oxidized biomass synthesis and can be limiting for cancer cell proliferation, but how cancer cells overcome this limitation in tumors is incompletely understood. Non-transformed cells in tumors can help cancer cells overcome metabolic limitations, particularly in pancreatic cancer, where pancreatic stellate cells (PSCs) promote cancer cell proliferation and tumor growth. However, whether PSCs affect the redox state of cancer cells is not known. By taking advantage of the endogenous fluorescence properties of reduced nicotinamide adenine dinucleotide cofactors and oxidized flavin adenine dinucleotide, we use optical imaging to assess the redox state of pancreatic cancer cells and PSCs and find that the redox state of cancer cells is more reduced while the redox state of PSCs is more oxidized. Direct interactions between PSCs and cancer cells promote a more oxidized state in cancer cells, suggesting that metabolic interactions between cancer cells and PSCs is a mechanism to overcome the redox limitations of cell proliferation in pancreatic cancer.

cancer biology↗

Cell Programmed Nutrient Partitioning in the Tumor Microenvironment

The tumor microenvironment (TME) includes transformed cancer and infiltrating immune cells1,2. Cancer cells can consume large quantities of glucose through Warburg metabolism3,4 that can be visualized with positron emission tomography (PET). While infiltrating immune cells also rely on glucose, disruptions to metabolism can contribute to tumor immunological evasion5-9. How immune cell metabolism is programmed or restrained by competition with cancer cells for nutrients, remains uncertain. Here we used PET tracers to measure the accessibility of glucose and glutamine to cell subsets in the TME. Surprisingly, myeloid cells including macrophages were the greatest consumers of intra-tumoral glucose, followed by T cells and cancer cells. Cancer cells, in contrast, had the highest glutamine uptake. This distinct nutrient partitioning was programmed through selective mTORC1 signaling and glucose or glutamine-related gene expression. Inhibition of glutamine uptake enhanced glucose uptake across tumor resident cell types and shifted macrophage phenotype, demonstrating glucose is not limiting in the TME. Thus, cancer cells are not the only cells in tumors which exhibit high glucose uptake in vivo and instead preferentially utilize glutamine over other cell types. We observe that intrinsic cellular programs can play a major role in the use of some nutrients. Together, these data argue cell selective partitioning of glucose and glutamine can be exploited to develop therapies and imaging strategies to alter the metabolic programs of specific cell populations in the TME.

cancer biology↗

Methionine synthase is essential for cancer cell proliferation in physiological folate environments

Targeting folate metabolism can be an effective way to treat cancer. The enzyme methionine synthase catalyzes a key reaction in both folate and methionine metabolism. Early work suggested that inhibiting methionine synthase might restrain tumor growth, though the mechanism remains unclear. We find that due to its specific role in processing folates, methionine synthase is required for cancer proliferation. However, widely used cell culture conditions obscure the proliferative and metabolic consequences of methionine synthase inhibition. Complete dependence on methionine synthase only arises when 5-methyl tetrahydrofolate, the major folate found in circulation, is the predominant folate source provided to cells. In these physiological folate conditions, methionine synthase activity is necessary to maintain intracellular levels of nucleotides, but not methionine. These data reveal that the extracellular environment can alter the essentiality of methionine synthase and suggest that this enzyme plays a crucial cell-autonomous role in supporting nucleotide synthesis and cell proliferation in physiological contexts.

cancer biology↗

Increased demand for NAD+ relative to ATP drives aerobic glycolysis

Aerobic glycolysis, or preferential fermentation of glucose-derived pyruvate to lactate despite available oxygen, is a hallmark of proliferative metabolism that is observed across many organisms and conditions. To better understand why aerobic glycolysis is associated with cell proliferation, we examined the metabolic consequence of activating the pyruvate dehydrogenase complex (PDH) to increase mitochondrial pyruvate oxidation at the expense of fermentation. We find that increasing PDH activity impairs cell proliferation by reducing the nicotinamide adenine dinucleotide cofactor ratio (NAD+/NADH). This change in NAD+/NADH ratio is caused by an increase in mitochondrial membrane potential that impairs mitochondrial electron transport and NAD+ regeneration. Uncoupling mitochondrial respiration from ATP synthesis or increasing ATP hydrolysis restores NAD+/NADH homeostasis and proliferation even when glucose oxidation is increased. These data suggest that when the demand for NAD+ to support oxidation reactions exceeds the demand for ATP consumption in cells, NAD+ regeneration by mitochondrial respiration becomes constrained, promoting fermentation despite available oxygen. This argues that cells engage in aerobic glycolysis when the cellular demand for NAD+ is in excess of the cellular demand for ATP.

biochemistry↗

Limited Environmental Serine Confers Sensitivity to PHGDH Inhibition in Brain Metastasis

A hallmark of metastasis is the adaptation of tumor cells to new environments. Although it is well established that the metabolic milieu of the brain is severely deprived of nutrients, particularly the amino acids serine and its catabolite glycine, how brain metastases rewire their metabolism to survive in the nutrient-limited environment of the brain is poorly understood. Here we demonstrate that cell-intrinsic de novo serine synthesis is a major determinant of brain metastasis. Whole proteome comparison of triple-negative breast cancer (TNBC) cells that differ in their capacity to colonize the brain reveals that 3-phosphoglycerate dehydrogenase (PHGDH), which catalyzes the rate-limiting step of glucose-derived serine synthesis, is the most significantly upregulated protein in cells that efficiently metastasize to the brain. Genetic silencing or pharmacological inhibition of PHGDH attenuated brain metastasis and improved overall survival in mice, whereas expression of catalytically active PHGDH in a non-brain trophic cell line promoted brain metastasis. Collectively, these findings indicate that nutrient availability determines serine synthesis pathway dependence in brain metastasis, and suggest that PHGDH inhibitors may be useful in the treatment of patients with cancers that have spread to the brain. Statement of SignificanceOur study highlights how limited serine and glycine availability within the brain microenvironment potentiates tumor cell sensitivity to serine synthesis inhibition. This finding underscores the importance of studying cancer metabolism in physiologically-relevant contexts, and provides a rationale for using PHGDH inhibitors to treat brain metastasis.

cancer biology↗

Targeting serine hydroxymethyltransferases 1 and 2 for T-cell acute lymphoblastic leukemia therapy.

Despite progress in the treatment of acute lymphoblastic leukemia (ALL), T-cell ALL (T-ALL) has limited treatment options particularly in the setting of relapsed/refractory disease. Using an unbiased genome-scale CRISPR-Cas9 screen we sought to identify pathway dependencies for T-ALL which could be harnessed for therapy development. Disruption of the one-carbon folate, purine and pyrimidine pathways scored as the top metabolic pathways required for T-ALL proliferation. We used a recently developed inhibitor of SHMT1 and SHMT2, RZ-2994, to characterize the effect of inhibiting these enzymes of the one-carbon folate pathway in T-ALL and found that T-ALL cell lines were differentially sensitive to RZ-2994, with a S/G2 cell cycle arrest. The effects of SHMT1/2 inhibition were rescued by formate supplementation. Loss of both SHMT1 and SHMT2 was necessary for impaired growth and cell cycle arrest, with suppression of both SHMT1 and SHMT2 impairing leukemia progression in vivo. RZ-2994 decreased leukemia burden in vivo and remained effective in the setting of methotrexate resistance in vitro. This study highlights the significance of the one-carbon folate pathway in T-ALL and supports further development of SHMT inhibitors for treatment of T-ALL and other cancers.

cancer biology↗

Pancreatic Stellate Cells Secrete Deoxycytidine Conferring Resistance to Gemcitabine in PDAC

Pancreatic ductal adenocarcinoma (PDAC) is a leading cause of cancer deaths in the United States. The deoxynucleoside analog gemcitabine is among the most effective therapies to treat PDAC; however, nearly all patients treated with gemcitabine either fail to respond or rapidly develop resistance. One hallmark of PDAC is a striking accumulation of stromal tissue surrounding the tumor, and this accumulation of stroma can contribute to therapy resistance. To better understand how stroma limits response to therapy, we investigated cell-extrinsic mechanisms of resistance to gemcitabine. We show that conditioned media from pancreatic stellate cells (PSC), as well as from other fibroblasts, protects PDAC cells from gemcitabine toxicity. We find that the PSC conditioned media protective effect is mediated by secretion of deoxycytidine, but not other deoxynucleosides, through equilibrative nucleoside transporters. Deoxycytidine inhibits the processing of gemcitabine in PDAC cells, thus reducing the effect of gemcitabine and other nucleoside analogs on cancer cells. Our results suggest that reducing deoxycytidine production in PSCs may increase the efficacy of nucleoside analog therapies. Additional InformationFunding: This project was funded in part by the NIH (NCI U54-217377), the MIT Center for Precision Cancer Medicine, and by the Koch Institute Support (core) Grant P30-CA14051 from the National Cancer Institute. S.D. was supported by the David H. Koch Fellowship in Cancer Research. A.N.L was a Robert Black Fellow of the Damon Runyon Cancer Research Foundation, DRG-2241-15 and was supported by a NIH Pathway to Independence Award (K99/R00), 1K99CA234221. M.T.H and M.G.V.H. acknowledges funding from the MIT Center for Precision Cancer Medicine and the Ludwig Center at MIT. M.G.V.H also acknowledges funding from the Lustgarten Foundation, SU2C, the MIT Center for Precision Cancer Medicine, the NCI, and an HHMI Faculty Scholar award. Competing interests: M.G.V.H. is a consultant and advisory board member for Agios Pharmaceuticals, Aeglea Biotherapeutics, and Auron Therapeutics.

cancer biology↗

Quantification of microenvironmental metabolites in murine cancer models reveals determinants of tumor nutrient availability

Cancer cell metabolism is heavily influenced by microenvironmental factors, including nutrient availability. Therefore, knowledge of microenvironmental nutrient levels is essential to understand tumor metabolism. To measure the extracellular nutrient levels available to tumors, we developed a quantitative metabolomics method to measure the absolute concentrations of >118 metabolites in plasma and tumor interstitial fluid, the extracellular fluid that perfuses tumors. Comparison of nutrient levels in tumor interstitial fluid and plasma revealed that the nutrients available to tumors differ from those present in circulation. Further, by comparing interstitial fluid nutrient levels between autochthonous and transplant models of murine pancreatic and lung adenocarcinoma, we found that tumor type, anatomical location and animal diet affect local nutrient availability. These data provide a comprehensive characterization of the nutrients present in the tumor microenvironment of widely used models of lung and pancreatic cancer and identify factors that influence metabolite levels in tumors.\n\nImpact StatementNutrient availability is an important tumor microenvironmental factor that impacts cancer cell biology; we developed methods to measure nutrients available to tumor cells and characterized factors that influence tumor nutrient availability.

cancer biology↗

Increased PHGDH expression uncouples hair follicle cycle progression and promotes inappropriate melanin accumulation

Copy number gain of the PHGDH gene that encodes the first enzyme of the serine biosynthesis pathway is found in some human cancers, including a subset of melanomas. In order to study the effect of increased PHGDH expression in tissues in vivo, we generated mice harboring a PHGDHtetO allele that allows tissue-specific, doxycycline-inducible PHGDH expression. Tissues and cells derived from PHGDHtetO mice exhibit increased serine biosynthesis. Histological examination of skin tissue from PHGDHtetO mice reveals the presence of melanin granules in anagen II hair follicles, despite the fact that melanin synthesis is normally closely coupled to the hair follicle cycle and does not begin until later in the cycle. This phenotype occurs in the absence of any global change in hair follicle cycle timing. The inappropriate presence of melanin early in the hair follicle cycle following PHGDH expression is also accompanied by increased melanocyte abundance in anagen II skin. Together, these data support a model in which PHGDH expression affects melanocyte proliferation and/or differentiation and may provide insight into how PHGDH expression impacts normal melanocyte biology to promote melanoma.\n\nSIGNIFICANCEThe significance behind copy number gain of PHGDH in human cancers is unclear. In this study, we generate a mouse model that mimics PHGDH gene copy number gain and characterize its effect on normal tissues. Increased PHGDH expression yields a phenotype of aberrant melanin production, which indicates that PHGDH expression may play a role in normal melanocyte biology. This result may provide insight into why PHGDH copy number gain is observed in melanoma more frequently than in most other tumor types.

developmental biology↗

Environmental cystine drives glutamine anaplerosis and sensitizes cells to glutaminase inhibition

Many cancer cell lines depend on extracellular glutamine as a major tri-carboxylic acid (TCA) cycle anaplerotic substrate to support proliferation in vitro. However, recent studies have suggested that some cells that depend on glutamine anaplerosis in culture rely much less on glutamine catabolism to proliferate in vivo, with environmental differences between tumors and cell culture influencing the extent of glutamine catabolism. Here we sought to better understand the environmental differences that cause differential dependence on glutamine for TCA cycle anaplerosis. We find that cells cultured in adult bovine serum, a condition that more closely reflects the nutrients available to cells in vivo, leads to decreased glutamine catabolism and reliance on glutamine anaplerosis compared to standard tissue culture conditions. By analyzing the nutrient differences between bovine serum and media, we find that levels of a single nutrient, cystine, can account for the differential dependence on glutamine in these different environmental contexts. Further, we show that cystine levels dictate glutamine dependence via the cystine/glutamate antiporter xCT/SLC7A11, and that environmental cystine levels in conjunction with xCT/SLC7A11 expression is necessary and sufficient to drive increased glutamine anaplerosis, defining important determinants of glutamine anaplerosis and glutaminase dependence in cancer cells.

biochemistry↗