Concurrent loss of LKB1 and KEAP1 enhances SHMT-mediated antioxidant defence in KRAS-mutant lung cancer.

Non-small-cell lung cancer (NSCLC) with concurrent mutations in KRAS and the tumour suppressor LKB1 (KL NSCLC) is refractory to most therapies and has one of the worst predicted outcomes. Here we describe a KL-induced metabolic vulnerability associated with serine-glycine-one-carbon (SGOC) metabolism. Using RNA-seq and metabolomics data from human NSCLC, we uncovered that LKB1 loss enhanced SGOC metabolism via serine hydroxymethyltransferase (SHMT). LKB1 loss, in collaboration with KEAP1 loss, activated SHMT through inactivation of the salt-induced kinase (SIK)-NRF2 axis and satisfied the increased demand for one-carbon units necessary for antioxidant defence. Chemical and genetic SHMT suppression increased cellular sensitivity to oxidative stress and cell death. Further, the SHMT inhibitor enhanced the in vivo therapeutic efficacy of paclitaxel (first-line NSCLC therapy inducing oxidative stress) in KEAP1-mutant KL tumours. The data reveal how this highly aggressive molecular subtype of NSCLC fulfills their metabolic requirements and provides insight into therapeutic strategies.

Electron transport chain inhibition increases cellular dependence on purine transport and salvage.

Mitochondria house many metabolic pathways required for homeostasis and growth. To explore how human cells respond to mitochondrial dysfunction, we performed metabolomics in fibroblasts from patients with various mitochondrial disorders and cancer cells with electron transport chain (ETC) blockade. These analyses revealed extensive perturbations in purine metabolism, and stable isotope tracing demonstrated that ETC defects suppress de novo purine synthesis while enhancing purine salvage. In human lung cancer, tumors with markers of low oxidative mitochondrial metabolism exhibit enhanced expression of the salvage enzyme hypoxanthine phosphoribosyl transferase 1 (HPRT1) and high levels of the HPRT1 product inosine monophosphate. Mechanistically, ETC blockade activates the pentose phosphate pathway, providing phosphoribosyl diphosphate to drive purine salvage supplied by uptake of extracellular bases. Blocking HPRT1 sensitizes cancer cells to ETC inhibition. These findings demonstrate how cells remodel purine metabolism upon ETC blockade and uncover a new metabolic vulnerability in tumors with low respiration.

Severely polarized extracellular acidity around tumour cells.

Extracellular pH impacts many molecular, cellular and physiological processes, and hence is tightly regulated. Yet, in tumours, dysregulated cancer cell metabolism and poor vascular perfusion cause the tumour microenvironment to become acidic. Here by leveraging fluorescent pH nanoprobes with a transistor-like activation profile at a pH of 5.3, we show that, in cancer cells, hydronium ions are excreted into a small extracellular region. Such severely polarized acidity (pH <5.3) is primarily caused by the directional co-export of protons and lactate, as we show for a diverse panel of cancer cell types via the genetic knockout or inhibition of monocarboxylate transporters, and also via nanoprobe activation in multiple tumour models in mice. We also observed that such spot acidification in ex vivo stained snap-frozen human squamous cell carcinoma tissue correlated with the expression of monocarboxylate transporters and with the exclusion of cytotoxic T cells. Severely spatially polarized tumour acidity could be leveraged for cancer diagnosis and therapy.

Metabolic signatures of thymomas: potential biomarkers and treatment targets.

OBJECTIVES: A study of tumour metabolic reprogramming has revealed disease biomarkers and avenues for therapeutic intervention. Metabolic reprogramming in thymoma is currently understudied and largely unknown. This study utilized metabolomics and isotope tracing with 13C-glucose to metabolically investigate thymomas, adjacent thymic tissue and benign thymic lesions. METHODS: From 2017 to 2021, 20 patients with a suspected thymoma were recruited to this prospective Institutional Review Board approved clinical trial. At the time of surgery, 11 patients were infused with 13C-glucose, a stable, non-radioactive tracer which reports the flow of carbon through metabolic pathways. Samples were analysed by mass spectrometry to measure the abundance of >200 metabolites.13C enrichment was measured in patients who received 13C-glucose infusions. RESULTS: Histological analysis showed that 9 patients had thymomas of diverse subtypes and 11 patients had benign cysts. In our metabolomic analysis, thymomas could be distinguished from both adjacent thymus tissue and benign lesions by metabolite abundances. Metabolites in pyrimidine biosynthesis and glycerophospholipid metabolism were differentially expressed across these tissues.13C-glucose infusions revealed differential labelling patterns in thymoma compared to benign cysts and normal thymus tissue. The lactate/3PG labelling ratio, a metabolic marker in aggressive lung tumours correlated with lactate uptake, was increased in thymomas (1.579) compared to normal thymus (0.945) and benign masses (0.807) (thymic tissue versus tumour P = 0.021, tumour versus benign P = 0.013). CONCLUSIONS: We report metabolic biomarkers, including differential 13C labelling of metabolites from central metabolism, that distinguish thymomas from benign tissues. Altered glucose and lactate metabolism warrant further investigation and may provide novel therapeutic targets for thymoma.

Metabolic pathway analysis using stable isotopes in patients with cancer.

Metabolic reprogramming is central to malignant transformation and cancer cell growth. How tumours use nutrients and the relative rates of reprogrammed pathways are areas of intense investigation. Tumour metabolism is determined by a complex and incompletely defined combination of factors intrinsic and extrinsic to cancer cells. This complexity increases the value of assessing cancer metabolism in disease-relevant microenvironments, including in patients with cancer. Stable-isotope tracing is an informative, versatile method for probing tumour metabolism in vivo. It has been used extensively in preclinical models of cancer and, with increasing frequency, in patients with cancer. In this Review, we describe approaches for using in vivo isotope tracing to define fuel preferences and pathway engagement in tumours, along with some of the principles that have emerged from this work. Stable-isotope infusions reported so far have revealed that in humans, tumours use a diverse set of nutrients to supply central metabolic pathways, including the tricarboxylic acid cycle and amino acid synthesis. Emerging data suggest that some activities detected by stable-isotope tracing correlate with poor clinical outcomes and may drive cancer progression. We also discuss current challenges in isotope tracing, including comparisons of in vivo and in vitro models, and opportunities for future discovery in tumour metabolism.

Trans-vaccenic acid reprograms CD8+ T cells and anti-tumour immunity.

Diet-derived nutrients are inextricably linked to human physiology by providing energy and biosynthetic building blocks and by functioning as regulatory molecules. However, the mechanisms by which circulating nutrients in the human body influence specific physiological processes remain largely unknown. Here we use a blood nutrient compound library-based screening approach to demonstrate that dietary trans-vaccenic acid (TVA) directly promotes effector CD8+ T cell function and anti-tumour immunity in vivo. TVA is the predominant form of trans-fatty acids enriched in human milk, but the human body cannot produce TVA endogenously1. Circulating TVA in humans is mainly from ruminant-derived foods including beef, lamb and dairy products such as milk and butter2,3, but only around 19% or 12% of dietary TVA is converted to rumenic acid by humans or mice, respectively4,5. Mechanistically, TVA inactivates the cell-surface receptor GPR43, an immunomodulatory G protein-coupled receptor activated by its short-chain fatty acid ligands6-8. TVA thus antagonizes the short-chain fatty acid agonists of GPR43, leading to activation of the cAMP-PKA-CREB axis for enhanced CD8+ T cell function. These findings reveal that diet-derived TVA represents a mechanism for host-extrinsic reprogramming of CD8+ T cells as opposed to the intrahost gut microbiota-derived short-chain fatty acids. TVA thus has translational potential for the treatment of tumours.

Adipocytes reprogram cancer cell metabolism by diverting glucose towards glycerol-3-phosphate thereby promoting metastasis.

In the tumor microenvironment, adipocytes function as an alternate fuel source for cancer cells. However, whether adipocytes influence macromolecular biosynthesis in cancer cells is unknown. Here we systematically characterized the bidirectional interaction between primary human adipocytes and ovarian cancer (OvCa) cells using multi-platform metabolomics, imaging mass spectrometry, isotope tracing and gene expression analysis. We report that, in OvCa cells co-cultured with adipocytes and in metastatic tumors, a part of the glucose from glycolysis is utilized for the biosynthesis of glycerol-3-phosphate (G3P). Normoxic HIF1α protein regulates the altered flow of glucose-derived carbons in cancer cells, resulting in increased glycerophospholipids and triacylglycerol synthesis. The knockdown of HIF1α or G3P acyltransferase 3 (a regulatory enzyme of glycerophospholipid synthesis) reduced metastasis in xenograft models of OvCa. In summary, we show that, in an adipose-rich tumor microenvironment, cancer cells generate G3P as a precursor for critical membrane and signaling components, thereby promoting metastasis. Targeting biosynthetic processes specific to adipose-rich tumor microenvironments might be an effective strategy against metastasis.

Electron transport chain inhibition increases cellular dependence on purine transport and salvage.

Cancer cells reprogram their metabolism to support cell growth and proliferation in harsh environments. While many studies have documented the importance of mitochondrial oxidative phosphorylation (OXPHOS) in tumor growth, some cancer cells experience conditions of reduced OXPHOS in vivo and induce alternative metabolic pathways to compensate. To assess how human cells respond to mitochondrial dysfunction, we performed metabolomics in fibroblasts and plasma from patients with inborn errors of mitochondrial metabolism, and in cancer cells subjected to inhibition of the electron transport chain (ETC). All these analyses revealed extensive perturbations in purine-related metabolites; in non-small cell lung cancer (NSCLC) cells, ETC blockade led to purine metabolite accumulation arising from a reduced cytosolic NAD + /NADH ratio (NADH reductive stress). Stable isotope tracing demonstrated that ETC deficiency suppressed de novo purine nucleotide synthesis while enhancing purine salvage. Analysis of NSCLC patients infused with [U- 13 C]glucose revealed that tumors with markers of low oxidative mitochondrial metabolism exhibited high expression of the purine salvage enzyme HPRT1 and abundant levels of the HPRT1 product inosine monophosphate (IMP). ETC blockade also induced production of ribose-5' phosphate (R5P) by the pentose phosphate pathway (PPP) and import of purine nucleobases. Blocking either HPRT1 or nucleoside transporters sensitized cancer cells to ETC inhibition, and overexpressing nucleoside transporters was sufficient to drive growth of NSCLC xenografts. Collectively, this study mechanistically delineates how cells compensate for suppressed purine metabolism in response to ETC blockade, and uncovers a new metabolic vulnerability in tumors experiencing NADH excess.

In vivo characterization of glutamine metabolism identifies therapeutic targets in clear cell renal cell carcinoma.

Targeting metabolic vulnerabilities has been proposed as a therapeutic strategy in renal cell carcinoma (RCC). Here, we analyzed the metabolism of patient-derived xenografts (tumorgrafts) from diverse subtypes of RCC. Tumorgrafts from VHL-mutant clear cell RCC (ccRCC) retained metabolic features of human ccRCC and engaged in oxidative and reductive glutamine metabolism. Genetic silencing of isocitrate dehydrogenase-1 or isocitrate dehydrogenase-2 impaired reductive labeling of tricarboxylic acid (TCA) cycle intermediates in vivo and suppressed growth of tumors generated from tumorgraft-derived cells. Glutaminase inhibition reduced the contribution of glutamine to the TCA cycle and resulted in modest suppression of tumorgraft growth. Infusions with [amide-15N]glutamine revealed persistent amidotransferase activity during glutaminase inhibition, and blocking these activities with the amidotransferase inhibitor JHU-083 also reduced tumor growth in both immunocompromised and immunocompetent mice. We conclude that ccRCC tumorgrafts catabolize glutamine via multiple pathways, perhaps explaining why it has been challenging to achieve therapeutic responses in patients by inhibiting glutaminase.

Carbon source availability drives nutrient utilization in CD8+ T cells.

How environmental nutrient availability impacts T cell metabolism and function remains poorly understood. Here, we report that the presence of physiologic carbon sources (PCSs) in cell culture medium broadly impacts glucose utilization by CD8+ T cells, independent of transcriptional changes in metabolic reprogramming. The presence of PCSs reduced glucose contribution to the TCA cycle and increased effector function of CD8+ T cells, with lactate directly fueling the TCA cycle. In fact, CD8+ T cells responding to Listeria infection preferentially consumed lactate over glucose as a TCA cycle substrate in vitro, with lactate enhancing T cell bioenergetic and biosynthetic capacity. Inhibiting lactate-dependent metabolism in CD8+ T cells by silencing lactate dehydrogenase A (Ldha) impaired both T cell metabolic homeostasis and proliferative expansion in vivo. Together, our data indicate that carbon source availability shapes T cell glucose metabolism and identifies lactate as a bioenergetic and biosynthetic fuel for CD8+ effector T cells.

In vivo isotope tracing reveals a requirement for the electron transport chain in glucose and glutamine metabolism by tumors.

In mice and humans with cancer, intravenous 13C-glucose infusion results in 13C labeling of tumor tricarboxylic acid (TCA) cycle intermediates, indicating that pyruvate oxidation in the TCA cycle occurs in tumors. The TCA cycle is usually coupled to the electron transport chain (ETC) because NADH generated by the cycle is reoxidized to NAD+ by the ETC. However, 13C labeling does not directly report ETC activity, and other pathways can oxidize NADH, so the ETC's role in these labeling patterns is unverified. We examined the impact of the ETC complex I inhibitor IACS-010759 on tumor 13C labeling. IACS-010759 suppresses TCA cycle labeling from glucose or lactate and increases labeling from glutamine. Cancer cells expressing yeast NADH dehydrogenase-1, which recycles NADH to NAD+ independently of complex I, display normalized labeling when complex I is inhibited, indicating that cancer cell ETC activity regulates TCA cycle metabolism and 13C labeling from multiple nutrients.

Compartmentalized metabolism supports midgestation mammalian development.

Mammalian embryogenesis requires rapid growth and proper metabolic regulation1. Midgestation features increasing oxygen and nutrient availability concomitant with fetal organ development2,3. Understanding how metabolism supports development requires approaches to observe metabolism directly in model organisms in utero. Here we used isotope tracing and metabolomics to identify evolving metabolic programmes in the placenta and embryo during midgestation in mice. These tissues differ metabolically throughout midgestation, but we pinpointed gestational days (GD) 10.5-11.5 as a transition period for both placenta and embryo. Isotope tracing revealed differences in carbohydrate metabolism between the tissues and rapid glucose-dependent purine synthesis, especially in the embryo. Glucose's contribution to the tricarboxylic acid (TCA) cycle rises throughout midgestation in the embryo but not in the placenta. By GD12.5, compartmentalized metabolic programmes are apparent within the embryo, including different nutrient contributions to the TCA cycle in different organs. To contextualize developmental anomalies associated with Mendelian metabolic defects, we analysed mice deficient in LIPT1, the enzyme that activates 2-ketoacid dehydrogenases related to the TCA cycle4,5. LIPT1 deficiency suppresses TCA cycle metabolism during the GD10.5-GD11.5 transition, perturbs brain, heart and erythrocyte development and leads to embryonic demise by GD11.5. These data document individualized metabolic programmes in developing organs in utero.

Lyso-PAF, a biologically inactive phospholipid, contributes to RAF1 activation.

Phospholipase A2, group VII (PLA2G7) is widely recognized as a secreted, lipoprotein-associated PLA2 in plasma that converts phospholipid platelet-activating factor (PAF) to a biologically inactive product Lyso-PAF during inflammatory response. We report that intracellular PLA2G7 is selectively important for cell proliferation and tumor growth potential of melanoma cells expressing mutant NRAS, but not cells expressing BRAF V600E. Mechanistically, PLA2G7 signals through its product Lyso-PAF to contribute to RAF1 activation by mutant NRAS, which is bypassed by BRAF V600E. Intracellular Lyso-PAF promotes p21-activated kinase 2 (PAK2) activation by binding to its catalytic domain and altering ATP kinetics, while PAK2 significantly contributes to S338-phosphorylation of RAF1 in addition to PAK1. Furthermore, the PLA2G7-PAK2 axis is also required for full activation of RAF1 in cells stimulated by epidermal growth factor (EGF) or cancer cells expressing mutant KRAS. Thus, PLA2G7 and Lyso-PAF exhibit intracellular signaling functions as key elements of RAS-RAF1 signaling.

Cellular signals converge at the NOX2-SHP-2 axis to induce reductive carboxylation in cancer cells.

Environmental stresses, including hypoxia or detachment for anchorage independence, or attenuation of mitochondrial respiration through inhibition of electron transport chain induce reductive carboxylation in cells with an enhanced fraction of citrate arising through reductive metabolism of glutamine. This metabolic process contributes to redox homeostasis and sustains biosynthesis of lipids. Reductive carboxylation is often dependent on cytosolic isocitrate dehydrogenase 1 (IDH1). However, whether diverse cellular signals induce reductive carboxylation differentially or through a common signaling converging node remains unclear. We found that induction of reductive carboxylation commonly requires enhanced tyrosine phosphorylation and activation of IDH1, which, surprisingly, is achieved by attenuation of a cytosolic protein tyrosine phosphatase, Src homology region 2 domain-containing phosphatase-2 (SHP-2). Mechanistically, diverse signals induce reductive carboxylation by converging at upregulation of NADPH oxidase 2, leading to elevated cytosolic reactive oxygen species that consequently inhibit SHP-2. Together, our work elucidates the signaling basis underlying reductive carboxylation in cancer cells.

Detection of glucose-derived D- and L-lactate in cancer cells by the use of a chiral NMR shift reagent.

BACKGROUND: Excessive lactate production, a hallmark of cancer, is largely formed by the reduction of pyruvate via lactate dehydrogenase (LDH) to L-lactate. Although D-lactate can also be produced from glucose via the methylglyoxal pathway in small amounts, less is known about the amount of D-lactate produced in cancer cells. Since the stereoisomers of lactate cannot be distinguished by conventional 1H NMR spectroscopy, a chiral NMR shift reagent was used to fully resolve the 1H NMR resonances of D- and L-lactate. METHODS: The production of L-lactate from glucose and D-lactate from methylglyoxal was first demonstrated in freshly isolated red blood cells using the chiral NMR shift reagent, YbDO3A-trisamide. Then, two different cell lines with high GLO1 expression (H1648 and H 1395) were selected from a panel of over 80 well-characterized human NSCLC cell lines, grown to confluence in standard tissue culture media, washed with phosphate-buffered saline, and exposed to glucose in a buffer for 4 h. After 4 h, a small volume of extracellular fluid was collected and mixed with YbDO3A-trisamide for analysis by 1H NMR spectroscopy. RESULTS: A suspension of freshly isolated red blood cells exposed to 5mM glucose produced L-lactate as expected but very little D-lactate. To evaluate the utility of the chiral NMR shift reagent, methylglyoxal was then added to red cells along with glucose to stimulate the production of D-lactate via the glyoxalate pathway. In this case, both D-lactate and L-lactate were produced and their NMR chemical shifts assigned. NSCLC cell lines with different expression levels of GLO1 produced both L- and D-lactate after incubation with glucose and glutamine alone. A GLO1-deleted parental cell line (3553T3) showed no production of D-lactate from glucose while re-expression of GLO1 resulted in higher production of D-lactate. CONCLUSIONS: The shift-reagent-aided NMR technique demonstrates that D-lactate is produced from glucose in NSCLC cells via the methylglyoxal pathway. The biological role of D-lactate is uncertain but a convenient method for monitoring D-lactate production could provide new insights into the biological roles of D- versus L-lactate in cancer metabolism.

Stable isotope tracing to assess tumor metabolism in vivo.

Cancer cells undergo diverse metabolic adaptations to meet the energetic demands imposed by dysregulated growth and proliferation. Assessing metabolism in intact tumors allows the investigator to observe the combined metabolic effects of numerous cancer cell-intrinsic and -extrinsic factors that cannot be fully captured in culture models. We have developed methods to use stable isotope-labeled nutrients (e.g., [13C]glucose) to probe metabolic activity within intact tumors in vivo, in mice and humans. In these methods, the labeled nutrient is introduced to the circulation through an intravenous catheter prior to surgical resection of the tumor and adjacent nonmalignant tissue. Metabolism within these tissues during the infusion transfers the isotope label into metabolic intermediates from pathways supplied by the infused nutrient. Extracting metabolites from surgical specimens and analyzing their isotope labeling patterns provides information about metabolism in the tissue. We provide detailed information about this technique, from introduction of the labeled tracer through data analysis and interpretation, including streamlined approaches to quantify isotope labeling in informative metabolites extracted from tissue samples. We focus on infusions with [13C]glucose and the application of mass spectrometry to assess isotope labeling in intermediates from central metabolic pathways, including glycolysis, the tricarboxylic acid cycle and nonessential amino acid synthesis. We outline practical considerations to apply these methods to human subjects undergoing surgical resections of solid tumors. We also discuss the method's versatility and consider the relative advantages and limitations of alternative approaches to introduce the tracer, harvest the tissue and analyze the data.

Isotope tracing reveals glycolysis and oxidative metabolism in childhood tumors of multiple histologies.

Background: Survival among children with high-risk solid tumors remains poor. Reprogrammed metabolism promotes tumor growth and may contain therapeutic liabilities. Tumor metabolism has been assessed in adults using intra-operative 13C-glucose infusions. Pediatric tumors differ from adult cancers in their low mutational burden and derivation from embryonic tissues. Here we used 13C infusions to examine tumor metabolism in children, comparing phenotypes among tumor types and between childhood and adult cancers. Methods: Patients recruited to study NCT03686566 received an intra-operative infusion of [U-13C]glucose during tumor resection to evaluate central carbon pathways in the tumor, with concurrent metabolomics to provide a broad overview of metabolism. Differential characteristics were determined using multiple comparison tests and mixed effect analyses. Findings: We studied 23 tumors from 22 patients. All tumors analyzed by [U-13C]glucose contained labeling in glycolytic and tricarboxylic acid (TCA) cycle intermediates. Labeling in the TCA cycle indicated activity of pyruvate dehydrogenase (PDH) and pyruvate carboxylase (PC), with PDH predominating. Neuroblastomas had high lactate labeling relative to other childhood cancers and lung cancer, and were distinguished by abundant tyrosine catabolites consistent with catecholamine synthesis. Conclusions: Intra-operative [U13C]glucose infusions are safe and informative in pediatric cancer. Tumors of various histologies use glycolysis and oxidative metabolism, with subtype-selective differences evident from this small cohort. Expanding this cohort may uncover predictive biomarkers and therapeutic targets from tumor metabolism. Funding: N.C.I grants to P.L. (R21CA220090-01A1) and R.J.D. (R35CA22044901); H.H.M.I. funding to R.J.D.; Children's Clinical Research Advisory Committee funding to K.J.

The hexosamine biosynthesis pathway is a targetable liability in KRAS/LKB1 mutant lung cancer.

In non-small-cell lung cancer (NSCLC), concurrent mutations in the oncogene KRAS and the tumour suppressor STK11 (also known as LKB1) encoding the kinase LKB1 result in aggressive tumours prone to metastasis but with liabilities arising from reprogrammed metabolism. We previously demonstrated perturbed nitrogen metabolism and addiction to an unconventional pathway of pyrimidine synthesis in KRAS/LKB1 co-mutant cancer cells. To gain broader insight into metabolic reprogramming in NSCLC, we analysed tumour metabolomes in a series of genetically engineered mouse models with oncogenic KRAS combined with mutations in LKB1 or p53. Metabolomics and gene expression profiling pointed towards activation of the hexosamine biosynthesis pathway (HBP), another nitrogen-related metabolic pathway, in both mouse and human KRAS/LKB1 co-mutant tumours. KRAS/LKB1 co-mutant cells contain high levels of HBP metabolites, higher flux through the HBP pathway and elevated dependence on the HBP enzyme glutamine-fructose-6-phosphate transaminase [isomerizing] 2 (GFPT2). GFPT2 inhibition selectively reduced KRAS/LKB1 co-mutant tumour cell growth in culture, xenografts and genetically modified mice. Our results define a new metabolic vulnerability in KRAS/LKB1 co-mutant tumours and provide a rationale for targeting GFPT2 in this aggressive NSCLC subtype.

Concentration-dependent Early Antivascular and Antitumor Effects of Itraconazole in Non-Small Cell Lung Cancer.

PURPOSE: Itraconazole has been repurposed as an anticancer therapeutic agent for multiple malignancies. In preclinical models, itraconazole has antiangiogenic properties and inhibits Hedgehog pathway activity. We performed a window-of-opportunity trial to determine the biologic effects of itraconazole in human patients. EXPERIMENTAL DESIGN: Patients with non-small cell lung cancer (NSCLC) who had planned for surgical resection were administered with itraconazole 300 mg orally twice daily for 10-14 days. Patients underwent dynamic contrast-enhanced MRI and plasma collection for pharmacokinetic and pharmacodynamic analyses. Tissues from pretreatment biopsy, surgical resection, and skin biopsies were analyzed for itraconazole and hydroxyitraconazole concentration, and vascular and Hedgehog pathway biomarkers. RESULTS: Thirteen patients were enrolled in this study. Itraconazole was well-tolerated. Steady-state plasma concentrations of itraconazole and hydroxyitraconazole demonstrated a 6-fold difference across patients. Tumor itraconazole concentrations trended with and exceeded those of plasma. Greater itraconazole levels were significantly and meaningfully associated with reduction in tumor volume (Spearman correlation, -0.71; P = 0.05) and tumor perfusion (Ktrans; Spearman correlation, -0.71; P = 0.01), decrease in the proangiogenic cytokines IL1b (Spearman correlation, -0.73; P = 0.01) and GM-CSF (Spearman correlation, -1.00; P < 0.001), and reduction in tumor microvessel density (Spearman correlation, -0.69; P = 0.03). Itraconazole-treated tumors also demonstrated distinct metabolic profiles. Itraconazole treatment did not alter transcription of GLI1 and PTCH1 mRNA. Patient size, renal function, and hepatic function did not predict itraconazole concentrations. CONCLUSIONS: Itraconazole demonstrates concentration-dependent early antivascular, metabolic, and antitumor effects in patients with NSCLC. As the number of fixed dose cancer therapies increases, attention to interpatient pharmacokinetics and pharmacodynamics differences may be warranted.

Metabolic reprogramming and cancer progression.

Metabolic reprogramming is a hallmark of malignancy. As our understanding of the complexity of tumor biology increases, so does our appreciation of the complexity of tumor metabolism. Metabolic heterogeneity among human tumors poses a challenge to developing therapies that exploit metabolic vulnerabilities. Recent work also demonstrates that the metabolic properties and preferences of a tumor change during cancer progression. This produces distinct sets of vulnerabilities between primary tumors and metastatic cancer, even in the same patient or experimental model. We review emerging concepts about metabolic reprogramming in cancer, with particular attention on why metabolic properties evolve during cancer progression and how this information might be used to develop better therapeutic strategies.