Clinical development of metabolic inhibitors for oncology

Involvement of the pro-oncogenic enzyme fatty acid synthase in the hallmarks of cancer: a promising target in anti-cancer therapies

An accelerated de novo lipogenesis (DNL) flux is a common characteristic of cancer cells required to sustain a high proliferation rate. The DNL enzyme fatty acid synthase (FASN) is overexpressed in many cancers and is pivotal for the increased production of fatty acids. There is increasing evidences of the involvement of FASN in several hallmarks of cancer linked to its ability to promote cell proliferation via membranes biosynthesis. In this review we discuss about the implication of FASN in the resistance to cell death and in the deregulation of cellular energetics by increasing nucleic acids, protein and lipid synthesis. FASN also promotes cell proliferation, cell invasion, metastasis and angiogenesis by enabling the building of lipid rafts and consequently to the localization of oncogenic receptors such as HER2 and c-Met in membrane microdomains. Finally, FASN is involved in immune escape by repressing the activation of pro-inflammatory cells and promoting the recruitment of M2 macrophages and T regulatory cells in the tumor microenvironment. Here, we provide an overview of the involvement of the pro-oncogenic enzyme in the hallmarks of cancer making FASN a promising target in anti-cancer therapy to circumvent resistance to chemotherapies.

Metabolic reprogramming and interventions in endometrial carcinoma

Cancer cells are usually featured by metabolic adaptations that facilitate their growth, invasion, and metastasis. Thus, reprogramming of intracellular energy metabolism is currently one of the hotspots in the field of cancer research. Whereas aerobic glycolysis (known as the Warburg effect) has long been considered a dominant form of energy metabolism in cancer cells, emerging evidence indicates that other metabolic forms, especially oxidative phosphorylation (OXPHOS), may play a critical role at least in some types of cancer. Of note, women with metabolic syndromes (MetS), including obesity, hyperglycemia, dyslipidemia, and hypertension, have an increased risk of developing endometrial carcinoma (EC), suggesting a close link between metabolism and EC. Interestingly, the metabolic preferences vary among EC cell types, particularly cancer stem cells and chemotherapy-resistant cells. Currently, it is commonly accepted that glycolysis is the main energy provider in EC cells, while OXPHOS is reduced or impaired. Moreover, agents specifically targeting the glycolysis and/or OXPHOS pathways can inhibit tumor cell growth and promote chemosensitization. For example, metformin and weight control not only reduce the incidence of EC but also improve the prognosis of EC patients. In this review, we comprehensively overview the current in-depth understanding of the relationship between metabolism and EC and provide up-to-date insights into the development of novel therapies targeting energy metabolism for auxiliary treatment in combination with chemotherapy for EC, especially those resistant to conventional chemotherapy.

NRF2 activation induces NADH-reductive stress, providing a metabolic vulnerability in lung cancer

Multiple cancers regulate oxidative stress by activating the transcription factor NRF2 through mutation of its negative regulator, KEAP1. NRF2 has been studied extensively in KEAP1-mutant cancers; however, the role of this pathway in cancers with wild-type KEAP1 remains poorly understood. To answer this question, we induced NRF2 via pharmacological inactivation of KEAP1 in a panel of 50+ non-small cell lung cancer cell lines. Unexpectedly, marked decreases in viability were observed in >13% of the cell lines-an effect that was rescued by NRF2 ablation. Genome-wide and targeted CRISPR screens revealed that NRF2 induces NADH-reductive stress, through the upregulation of the NAD+-consuming enzyme ALDH3A1. Leveraging these findings, we show that cells treated with KEAP1 inhibitors or those with endogenous KEAP1 mutations are selectively vulnerable to Complex I inhibition, which impairs NADH oxidation capacity and potentiates reductive stress. Thus, we identify reductive stress as a metabolic vulnerability in NRF2-activated lung cancers.

Role of myeloid-derived suppressor cells in tumor recurrence

The establishment of primary tumor cells in distant organs, termed metastasis, is the principal cause of cancer mortality and is a crucial therapeutic target in oncology. Thus, it is critical to establish a better understanding of metastatic progression for the future development of improved therapeutic approaches. Indeed, such development requires insight into the timing of tumor cell dissemination and seeding of distant organs resulting in occult lesions. Following dissemination of tumor cells from the primary tumor, they can reside in niches in distant organs for years or decades, following which they can emerge as an overt metastasis. This timeline of metastatic dormancy is regulated by interactions between the tumor, its microenvironment, angiogenesis, and tumor antigen-specific T-cell responses. An improved understanding of the mechanisms and interactions responsible for immune evasion and tumor cell release from dormancy would help identify and aid in the development of novel targeted therapeutics. One such mediator of dormancy is myeloid derived suppressor cells (MDSC), whose number in the peripheral blood (PB) or infiltrating tumors has been associated with cancer stage, grade, patient survival, and metastasis in a broad range of tumor pathologies. Thus, extensive studies have revealed a role for MDSCs in tumor escape from adoptive and innate immune responses, facilitating tumor progression and metastasis; however, few studies have considered their role in dormancy. We have posited that MDSCs may regulate disseminated tumor cells resulting in resurgence of senescent tumor cells. In this review, we discuss clinical studies that address mechanisms of tumor recurrence including from dormancy, the role of MDSCs in their escape from dormancy during recurrence, the development of occult metastases, and the potential for MDSC inhibition as an approach to prolong the survival of patients with advanced malignancies. We stress that assessing the impact of therapies on MDSCs versus other cellular targets is challenging within the multimodality interventions required clinically.

Modulating Glycolysis to Improve Cancer Therapy

Cancer cells undergo metabolic reprogramming and switch to a 'glycolysis-dominant' metabolic profile to promote their survival and meet their requirements for energy and macromolecules. This phenomenon, also known as the 'Warburg effect,' provides a survival advantage to the cancer cells and make the tumor environment more pro-cancerous. Additionally, the increased glycolytic dependence also promotes chemo/radio resistance. A similar switch to a glycolytic metabolic profile is also shown by the immune cells in the tumor microenvironment, inducing a competition between the cancer cells and the tumor-infiltrating cells over nutrients. Several recent studies have shown that targeting the enhanced glycolysis in cancer cells is a promising strategy to make them more susceptible to treatment with other conventional treatment modalities, including chemotherapy, radiotherapy, hormonal therapy, immunotherapy, and photodynamic therapy. Although several targeting strategies have been developed and several of them are in different stages of pre-clinical and clinical evaluation, there is still a lack of effective strategies to specifically target cancer cell glycolysis to improve treatment efficacy. Herein, we have reviewed our current understanding of the role of metabolic reprogramming in cancer cells and how targeting this phenomenon could be a potential strategy to improve the efficacy of conventional cancer therapy.

FASN multi-omic characterization reveals metabolic heterogeneity in pancreatic and prostate adenocarcinoma

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) and prostate cancer (PCa) are among the most prevalent malignant tumors worldwide. There is now a comprehensive understanding of metabolic reprogramming as a hallmark of cancer. Fatty acid synthase (FASN) is a key regulator of the lipid metabolic network, providing energy to favor tumor proliferation and development. Whereas the biological role of FASN is known, its response and sensitivity to inhibition have not yet been fully established in these two cancer settings.

METHODS

To evaluate the association between FASN expression, methylation, prognosis, and mutational profile in PDAC and PCa, we interrogated public databases and surveyed online platforms using TCGA data. The STRING database was used to investigate FASN interactors, and the Gene Set Enrichment Analysis platform Reactome database was used to perform an enrichment analysis using data from RNA sequencing public databases of PDAC and PCa. In vitro models using PDAC and PCa cell lines were used to corroborate the expression of FASN, as shown by Western blot, and the effects of FASN inhibition on cell proliferation/cell cycle progression and mitochondrial respiration were investigated with MTT, colony formation assay, cell cycle analysis and MitoStress Test.

RESULTS

The expression of FASN was not modulated in PDAC compared to normal pancreatic tissues, while it was overexpressed in PCa, which also displayed a different level of promoter methylation. Based on tumor grade, FASN expression decreased in advanced stages of PDAC, but increased in PCa. A low incidence of FASN mutations was found for both tumors. FASN was overexpressed in PCa, despite not reaching statistical significance, and was associated with a worse prognosis than in PDAC. The biological role of FASN interactors correlated with lipid metabolism, and GSEA indicated that lipid-mediated mitochondrial respiration was enriched in PCa. Following validation of FASN overexpression in PCa compared to PDAC in vitro, we tested TVB-2640 as a FASN inhibitor. PCa proliferation arrest was modulated by FASN inhibition in a dose- and time-dependent manner, whereas PDAC proliferation was not altered. In line with this finding, mitochondrial respiration was found to be more affected in PCa than in PDAC. FASN inhibition interfered with metabolic signaling causing lipid accumulation and affecting cell viability with an impact on the replicative processes.

CONCLUSIONS

FASN exhibited differential expression patterns in PDAC and PCa, suggesting a different evolution during cancer progression. This was corroborated by the fact that both tumors responded differently to FASN inhibition in terms of proliferative potential and mitochondrial respiration, indicating that its use should reflect context specificity.

Partners in crime: The feedback loop between metabolic reprogramming and immune checkpoints in the tumor microenvironment

The tumor microenvironment (TME) is a complex and constantly changing cellular system composed of heterogeneous populations of tumor cells and non-transformed stromal cells, such as stem cells, fibroblasts, endothelial cells, pericytes, adipocytes, and innate and adaptive immune cells. Tumor, stromal, and immune cells consume available nutrients to sustain their proliferation and effector functions and, as a result of their metabolism, produce a wide array of by-products that gradually alter the composition of the milieu. The resulting depletion of essential nutrients and enrichment of by-products work together with other features of the hostile TME to inhibit the antitumor functions of immune cells and skew their phenotype to promote tumor progression. This review briefly describes the participation of the innate and adaptive immune cells in recognizing and eliminating tumor cells and how the gradual metabolic changes in the TME alter their antitumor functions. In addition, we discuss the overexpression of the immune checkpoints and their ligands as a result of nutrient deprivation and by-products accumulation, as well as the amplification of the metabolic alterations induced by the immune checkpoints, which creates an immunosuppressive feedback loop in the TME. Finally, the combination of metabolic and immune checkpoint inhibitors as a potential strategy to treat cancer and enhance the outcome of patients is highlighted.

Importance of lactate dehydrogenase (LDH) and monocarboxylate transporters (MCTs) in cancer cells

Background

In most regions, cancer ranks the second most frequent cause of death following cardiovascular disorders.

Aim

In this article, we review the various aspects of glycolysis with a focus on types of MCTs and the importance of lactate in cancer cells.

Results and Discussion

Metabolic changes are one of the first and most important alterations in cancer cells. Cancer cells use different pathways to survive, energy generation, growth, and proliferation compared to normal cells. The increase in glycolysis, which produces substances such as lactate and pyruvate, has an important role in metastases and invasion of cancer cells. Two important cellular proteins that play a role in the production and transport of lactate include lactate dehydrogenase and monocarboxylate transporters (MCTs). These molecules by their various isoforms and different tissue distribution help to escape the immune system and expansion of cancer cells under different conditions.

The exploitation of enzyme-based cancer immunotherapy

Cancer immunotherapy utilizes the immune system and its wide-ranging components to deliver anti-tumor responses. In immune escape mechanisms, tumor microenvironment-associated soluble factors and cell surface-bound molecules are mainly accountable for the dysfunctional activity of tumor-specific CD8⁺ T cells, natural killer (NK) cells, tumor associated macrophages (TAMs) and stromal cells. The myeloid-derived suppressor cells (MDSCs) and Foxp3⁺ regulatory T cells (Tregs), are also key tumor-promoting immune cells. These potent immunosuppressive networks avert tumor rejection at various stages, affecting immunotherapies' outcomes. Numerous clinical trials have elucidated that disruption of immunosuppression could be achieved via checkpoint inhibitors. Another approach utilizes enzymes that can restore the body's potential to counter cancer by triggering the immune system inhibited by the tumor microenvironment. These immunotherapeutic enzymes can catalyze an immunostimulatory signal and modulate the tumor microenvironment via effector molecules. Herein, we have discussed the immuno-metabolic roles of various enzymes like ATP-dephosphorylating ectoenzymes, inducible Nitric Oxide Synthase, phenylamine, tryptophan, and arginine catabolizing enzymes in cancer immunotherapy. Understanding the detailed molecular mechanisms of the enzymes involved in modulating the tumor microenvironment may help find new opportunities for cancer therapeutics.

An updated patent review of glutaminase inhibitors (2019-2022)

INTRODUCTION

Kidney-type glutaminase (GLS1), a key enzyme controlling the hydrolysis of glutamine to glutamate to resolve the 'glutamine addiction' of cancer cells, has been shown to play a central role in supporting cancer growth and proliferation. Therefore, the inhibition of GLS1 as a novel cancer treating strategy is of great interest.

AREAS COVERED

This review covers recent patents (2019-present) involving GLS1 inhibitors, which are mostly focused on their chemical structures, molecular mechanisms of action, pharmacokinetic properties, and potential clinical applications.

EXPERT OPINION

Currently, despite significant efforts, the search for potent GLS1 inhibitors has not resulted in the development of compounds for therapeutic applications. Most recent patents and literature focus on GLS1 inhibitors IPN60090 and DRP104, which have entered clinical trials. While other patent disclosures during this period have not generated any drug candidates, the clinical update will inform the potential of these inhibitors as promising therapeutic agents either as single or as combination interventions.

Targeting cancer-specific metabolic pathways for developing novel cancer therapeutics

Cancer is a heterogeneous disease characterized by various genetic and phenotypic aberrations. Cancer cells undergo genetic modifications that promote their proliferation, survival, and dissemination as the disease progresses. The unabated proliferation of cancer cells incurs an enormous energy demand that is supplied by metabolic reprogramming. Cancer cells undergo metabolic alterations to provide for increased energy and metabolite requirement; these alterations also help drive the tumor progression. Dysregulation in glucose uptake and increased lactate production via "aerobic glycolysis" were described more than 100 years ago, and since then, the metabolic signature of various cancers has been extensively studied. However, the extensive research in this field has failed to translate into significant therapeutic intervention, except for treating childhood-ALL with amino acid metabolism inhibitor L-asparaginase. Despite the growing understanding of novel metabolic alterations in tumors, the therapeutic targeting of these tumor-specific dysregulations has largely been ineffective in clinical trials. This chapter discusses the major pathways involved in the metabolism of glucose, amino acids, and lipids and highlights the inter-twined nature of metabolic aberrations that promote tumorigenesis in different types of cancer. Finally, we summarise the therapeutic interventions which can be used as a combinational therapy to target metabolic dysregulations that are unique or common in blood, breast, colorectal, lung, and prostate cancer.

Effects of metabolic cancer therapy on tumor microenvironment

Targeting tumor metabolism for cancer therapy is an old strategy. In fact, historically the first effective cancer therapeutics were directed at nucleotide metabolism. The spectrum of metabolic drugs considered in cancer increases rapidly - clinical trials are in progress for agents directed at glycolysis, oxidative phosphorylation, glutaminolysis and several others. These pathways are essential for cancer cell proliferation and redox homeostasis, but are also required, to various degrees, in other cell types present in the tumor microenvironment, including immune cells, endothelial cells and fibroblasts. How metabolism-targeted treatments impact these tumor-associated cell types is not fully understood, even though their response may co-determine the overall effectivity of therapy. Indeed, the metabolic dependencies of stromal cells have been overlooked for a long time. Therefore, it is important that metabolic therapy is considered in the context of tumor microenvironment, as understanding the metabolic vulnerabilities of both cancer and stromal cells can guide new treatment concepts and help better understand treatment resistance. In this review we discuss recent findings covering the impact of metabolic interventions on cellular components of the tumor microenvironment and their implications for metabolic cancer therapy.

Current Status of Novel Agents for the Treatment of B Cell Malignancies: What's Coming Next?

Resistance to death is one of the hallmarks of human B cell malignancies and often contributes to the lack of a lasting response to today's commonly used treatments. Drug discovery approaches designed to activate the death machinery have generated a large number of inhibitors of anti-apoptotic proteins from the B-cell lymphoma/leukemia 2 family and the B-cell receptor (BCR) signaling pathway. Orally administered small-molecule inhibitors of Bcl-2 protein and BCR partners (e.g., Bruton's tyrosine kinase and phosphatidylinositol-3 kinase) have already been included (as monotherapies or combination therapies) in the standard of care for selected B cell malignancies. Agonistic monoclonal antibodies and their derivatives (antibody-drug conjugates, antibody-radioisotope conjugates, bispecific T cell engagers, and chimeric antigen receptor-modified T cells) targeting tumor-associated antigens (TAAs, such as CD19, CD20, CD22, and CD38) are indicated for treatment (as monotherapies or combination therapies) of patients with B cell tumors. However, given that some patients are either refractory to current therapies or relapse after treatment, novel therapeutic strategies are needed. Here, we review current strategies for managing B cell malignancies, with a focus on the ongoing clinical development of more effective, selective drugs targeting these molecules, as well as other TAAs and signaling proteins. The observed impact of metabolic reprogramming on B cell pathophysiology highlights the promise of targeting metabolic checkpoints in the treatment of these disorders.

Metabolomics of Extracellular Vesicles: A Future Promise of Multiple Clinical Applications

Extracellular vesicles (EVs) can contain DNA, RNA, proteins and metabolic molecules from primary origins; they are coated with a phospholipid bilayer membrane and released by cells into the extracellular matrix. EVs can be obtained from various body liquids, including the blood, saliva, cerebrospinal fluid, and urine. As has been proved, EVs-mediated transfer of biologically active molecules is crucial for various physiological and pathological processes. Extensive investigations have already begun to explore the diagnosis and prognosis potentials for EVs. Furthermore, research has continued to recognize the critical role of nucleic acids and proteins in EVs. However, our understanding of the comprehensive effects of metabolites in these nanoparticles is currently limited and in its infancy. Therefore, we have attempted to summarize the recent research into the metabolomics of EVs in relation to potential clinical applications and discuss the problems and challenges that have occurred, to provide more guidance for the future development in this field.

Applying HT-SAXS to chemical ligand screening

Chemical probes are invaluable tools for investigating essential biological processes. Understanding how small-molecule probes engage biomolecular conformations is critical to developing their functional selectivity. High-throughput solution X-ray scattering is well-positioned to profile target-ligand complexes during probe development, bringing conformational insight and selection to traditional ligand binding assays. Access to high-quality synchrotron SAXS datasets and high-throughput data analysis now allows routine academic users to incorporate conformational information into small-molecule development pipelines. Here we describe a general approach for benchmarking and preparing HT-SAXS chemical screens from small fragment libraries. Using the allosteric oxidoreductase Apoptosis-Inducing Factor (AIF) as an exemplary system, we illustrate how HT-SAXS efficiently identifies an allosteric candidate among hits of a microscale thermophoresis ligand screen. We discuss considerations for pursuing HT-SAXS chemical screening with other systems of interest and reflect on advances to extend screening throughput and sensitivity.

Discovery of DRP-104, a tumor-targeted metabolic inhibitor prodrug

6-Diazo-5-oxo-l-norleucine (DON) is a glutamine antagonist that suppresses cancer cell metabolism but concurrently enhances the metabolic fitness of tumor CD8+ T cells. DON showed promising efficacy in clinical trials; however, its development was halted by dose-limiting gastrointestinal (GI) toxicities. Given its clinical potential, we designed DON peptide prodrugs and found DRP-104 [isopropyl(S)-2-((S)-2-acetamido-3-(1H-indol-3-yl)-propanamido)-6-diazo-5-oxo-hexanoate] that was preferentially bioactivated to DON in tumor while bioinactivated to an inert metabolite in GI tissues. In drug distribution studies, DRP-104 delivered a prodigious 11-fold greater exposure of DON to tumor versus GI tissues. DRP-104 affected multiple metabolic pathways in tumor, including decreased glutamine flux into the TCA cycle. In efficacy studies, both DRP-104 and DON caused complete tumor regression; however, DRP-104 had a markedly improved tolerability profile. DRP-104's effect was CD8+ T cell dependent and resulted in robust immunologic memory. DRP-104 represents a first-in-class prodrug with differential metabolism in target versus toxicity tissue. DRP-104 is now in clinical trials under the FDA Fast Track designation.

Glutamine metabolism and radiosensitivity: Beyond the Warburg effect

Mounting data suggest that cancer cell metabolism can be utilized therapeutically to halt cell proliferation, metastasis and disease progression. Radiation therapy is a critical component of cancer treatment in curative and palliative settings. The use of metabolism-based therapeutics has become increasingly popular in combination with radiotherapy to overcome radioresistance. Over the past year, a focus on glutamine metabolism in the setting of cancer therapy has emerged. In this mini-review, we discuss several important ways (DNA damage repair, oxidative stress, epigenetic modification and immune modulation) glutamine metabolism drives cancer growth and progression, and present data that inhibition of glutamine utilization can lead to radiosensitization in preclinical models. Future research is needed in the clinical realm to determine whether glutamine antagonism is a feasible synergistic therapy that can be combined with radiotherapy.

2-Deoxyglucose, an Inhibitor of Glycolysis, Enhances the Oncolytic Effect of Coxsackievirus

Glioblastoma multiforme (GBM) is one of the most common types of brain tumor. Despite intensive research, patients with GBM have a poor prognosis due to a very high rate of relapse and significant side effects of the treatment, with a median survival of 14.6 months. Oncolytic viruses are considered a promising strategy to eliminate GBM and other types of cancer, and several viruses have already been introduced into clinical practice. However, identification of the factors that underly the sensitivity of tumor species to oncolytic viruses or that modulate their clinical efficacy remains an important target. Here, we show that Coxsackievirus B5 (CVB5) demonstrates high oncolytic potential towards GBM primary cell species and cell lines. Moreover, 2-deoxyglucose (2DG), an inhibitor of glycolysis, potentiates the cytopathic effects of CVB5 in most of the cancer cell lines tested. The cells in which the inhibition of glycolysis enhanced oncolysis are characterized by high mitochondrial respiratory activity and glycolytic capacity, as determined by Seahorse analysis. Thus, 2-deoxyglucose and other analogs should be considered as adjuvants for oncolytic therapy of glioblastoma multiforme.

Advances in Understanding of Metabolism of B-Cell Lymphoma: Implications for Therapy

There have been significant recent advances in the understanding of the role of metabolism in normal and malignant B-cell biology. Previous research has focused on the role of MYC and mammalian target of rapamycin (mTOR) and how these interact with B-cell receptor signaling and hypoxia to regulate glycolysis, glutaminolysis, oxidative phosphorylation (OXPHOS) and related metabolic pathways in germinal centers. Many of the commonest forms of lymphoma arise from germinal center B-cells, reflecting the physiological attenuation of normal DNA damage checkpoints to facilitate somatic hypermutation of the immunoglobulin genes. As a result, these lymphomas can inherit the metabolic state of their cell-of-origin. There is increasing interest in the potential of targeting metabolic pathways for anti-cancer therapy. Some metabolic inhibitors such as methotrexate have been used to treat lymphoma for decades, with several new agents being recently licensed such as inhibitors of phosphoinositide-3-kinase. Several other inhibitors are in development including those blocking mTOR, glutaminase, OXPHOS and monocarboxylate transporters. In addition, recent work has highlighted the importance of the interaction between diet and cancer, with particular focus on dietary modifications that restrict carbohydrates and specific amino acids. This article will review the current state of this field and discuss future developments.

Druggable Metabolic Vulnerabilities Are Exposed and Masked during Progression to Castration Resistant Prostate Cancer

There is an urgent need for exploring new actionable targets other than androgen receptor to improve outcome from lethal castration-resistant prostate cancer. Tumor metabolism has reemerged as a hallmark of cancer that drives and supports oncogenesis. In this regard, it is important to understand the relationship between distinctive metabolic features, androgen receptor signaling, genetic drivers in prostate cancer, and the tumor microenvironment (symbiotic and competitive metabolic interactions) to identify metabolic vulnerabilities. We explore the links between metabolism and gene regulation, and thus the unique metabolic signatures that define the malignant phenotypes at given stages of prostate tumor progression. We also provide an overview of current metabolism-based pharmacological strategies to be developed or repurposed for metabolism-based therapeutics for castration-resistant prostate cancer.

Pathological implications of metabolic reprogramming and its therapeutic potential in medulloblastoma

Tumor-specific alterations in metabolism have been recognized to sustain the production of ATP and macromolecules needed for cell growth, division and survival in many cancer types. However, metabolic heterogeneity poses a challenge for the establishment of effective anticancer therapies that exploit metabolic vulnerabilities. Medulloblastoma (MB) is one of the most heterogeneous malignant pediatric brain tumors, divided into four molecular subgroups (Wingless, Sonic Hedgehog, Group 3 and Group 4). Recent progresses in genomics, single-cell sequencing, and novel tumor models have updated the classification and stratification of MB, highlighting the complex intratumoral cellular diversity of this cancer. In this review, we emphasize the mechanisms through which MB cells rewire their metabolism and energy production networks to support and empower rapid growth, survival under stressful conditions, invasion, metastasis, and resistance to therapy. Additionally, we discuss the potential clinical benefits of currently available drugs that could target energy metabolism to suppress MB progression and increase the efficacy of the current MB therapies.

Metabolic cross-talk within the bone marrow milieu: focus on multiple myeloma

Cancer cells are well-known for their capacity to adapt their metabolism to their increasing energy demands which is necessary for tumor progression. This is no different for Multiple Myeloma (MM), a hematological cancer which develops in the bone marrow (BM), whereby the malignant plasma cells accumulate and impair normal BM functions. It has become clear that the hypoxic BM environment contributes to metabolic rewiring of the MM cells, including changes in metabolite levels, increased/decreased activity of metabolic enzymes and metabolic shifts. These adaptations will lead to a pro-tumoral environment stimulating MM growth and drug resistance In this review, we discuss the identified metabolic changes in MM and the BM microenvironment and summarize how these identified changes have been targeted (by inhibitors, genetic approaches or deprivation studies) in order to block MM progression and survival.

Lipids in cancer: a global view of the contribution of lipid pathways to metastatic formation and treatment resistance

Lipids are essential constituents for malignant tumors, as they are absolutely required for tumor growth and dissemination. Provided by the tumor microenvironment (TME) or by cancer cells themselves through activation of de novo synthesis pathways, they orchestrate a large variety of pro-tumorigenic functions. Importantly, TME cells, especially immune cells, cancer-associated fibroblasts (CAFs) and cancer-associated adipocytes (CAAs), are also prone to changes in their lipid content, which hinder or promote tumor aggressiveness. In this review, we address the significant findings for lipid contribution in tumor progression towards a metastatic disease and in the poor response to therapeutic treatments. We also highlight the benefits of targeting lipid pathways in preclinical models to slow down metastasis development and overcome chemo-and immunotherapy resistance.

Statin shapes inflamed tumor microenvironment and enhances immune checkpoint blockade in non-small cell lung cancer

Immune checkpoint blockade (ICB) therapy has achieved breakthroughs in the treatment of advanced non-small cell lung cancer (NSCLC). Nevertheless, the low response due to immuno-cold tumor microenvironment (TME) largely limits the application of ICB therapy. Based on the glycolytic/cholesterol synthesis axis, a stratification framework for EGFR wild-type NSCLC was developed to summarize the metabolic features of immuno-cold and immuno-hot tumors. The cholesterol subgroup displays the worst prognosis in immuno-cold NSCLC with significant enrichment of the cholesterol gene signature, indicating targeting cholesterol synthesis is essential for the therapy for immuno-cold NSCLC. Statin, the inhibitor for cholesterol synthesis, can suppress the aggressiveness of NSCLC in vitro and in vivo and also drastically reverse immuno-cold to an inflamed phenotype in vivo which exhibited a higher response to ICB therapy. Moreover, both our in-house data and meta-analysis further support that statin can significantly enhance ICB efficacy. In terms of preliminary mechanisms, statin could transcriptionally inhibit PD-L1 expression and induce ferroptosis in NSCLC cells. Overall, we reveal the significance of cholesterol synthesis in NSCLC and demonstrate the improved therapeutic efficacy of ICB in combination with statin. These findings could provide a innovative clinical insight to treat NSCLC patients with immuno-cold tumors.

Novel Radioiodinated and Radiofluorinated Analogues of FT-2102 for SPECT or PET Imaging of mIDH1 Mutant Tumours

Isocitrate dehydrogenases (IDHs) are metabolic enzymes commonly mutated in human cancers (glioma, acute myeloid leukaemia, chondrosarcoma, and intrahepatic cholangiocarcinoma). These mutated variants of IDH (mIDH) acquire a neomorphic activity, namely, conversion of α-ketoglutarate to the oncometabolite D-2-hydroxyglutarate involved in tumourigenesis. Thus, mIDHs have emerged as highly promising therapeutic targets, and several mIDH specific inhibitors have been developed. However, the evaluation of mIDH status, currently performed by biopsy, is essential for patient stratification and thus treatment and follow-up. We report herein the development of new radioiodinated and radiofluorinated analogues of olutasidenib (FT-2102) as tools for noninvasive single photon emission computed tomography (SPECT) or positron emission tomography (PET) imaging of mIDH1 up- and dysregulation in tumours. Nonradiolabelled derivatives 2 and 3 halogenated at position 6 of the quinolinone scaffold were synthesised and tested in vitro for their inhibitory potencies and selectivities in comparison with the lead compound FT-2102. Using a common organotin precursor, (S)-[¹²⁵I]2 and (S)-[¹⁸F]3 were efficiently synthesised by radio-iododemetallation and copper-mediated radiofluorination, respectively. Both radiotracers were stable at room temperature in saline or DPBS solution and at 37 °C in mouse serum, allowing future planning of their in vitro and in vivo evaluations in glioma and chondrosarcoma models.