Altered energy metabolism in cancer: a unique opportunity for therapeutic intervention

Including glutamine in a resource allocation model of energy metabolism in cancer and yeast cells

Energy metabolism is crucial for all living cells, especially during fast growth or stress scenarios. Many cancer and activated immune cells (Warburg effect) or yeasts (Crabtree effect) mostly rely on aerobic glucose fermentation leading to lactate or ethanol, respectively, to generate ATP. In recent years, several mathematical models have been proposed to explain the Warburg effect on theoretical grounds. Besides glucose, glutamine is a very important substrate for eukaryotic cells-not only for biosynthesis, but also for energy metabolism. Here, we present a minimal constraint-based stoichiometric model for explaining both the classical Warburg effect and the experimentally observed respirofermentation of glutamine (WarburQ effect). We consider glucose and glutamine respiration as well as the respective fermentation pathways. Our resource allocation model calculates the ATP production rate, taking into account enzyme masses and, therefore, pathway costs. While our calculation predicts glucose fermentation to be a superior energy-generating pathway in human cells, different enzyme characteristics in yeasts reduce this advantage, in some cases to such an extent that glucose respiration is preferred. The latter is observed for the fungal pathogen Candida albicans, which is a known Crabtree-negative yeast. Further, optimization results show that glutamine is a valuable energy source and important substrate under glucose limitation, in addition to its role as a carbon and nitrogen source of biomass in eukaryotic cells. In conclusion, our model provides insights that glutamine is an underestimated fuel for eukaryotic cells during fast growth and infection scenarios and explains well the observed parallel respirofermentation of glucose and glutamine in several cell types.

Fasting in combination with the cocktail Sorafenib:Metformin blunts cellular plasticity and promotes liver cancer cell death via poly-metabolic exhaustion

PURPOSE

Dual-Interventions targeting glucose and oxidative metabolism are receiving increasing attention in cancer therapy. Sorafenib (S) and Metformin (M), two gold-standards in liver cancer, are known for their mitochondrial inhibitory capacity. Fasting, a glucose-limiting strategy, is also emerging as chemotherapy adjuvant. Herein, we explore the anti-carcinogenic response of nutrient restriction in combination with sorafenib:metformin (NR-S:M).

RESULTS

Our data demonstrates that, independently of liver cancer aggressiveness, fasting synergistically boosts the anti-proliferative effects of S:M co-treatment. Metabolic and Cellular plasticity was determined by the examination of mitochondrial and glycolytic activity, cell cycle modulation, activation of cellular apoptosis, and regulation of key signaling and metabolic enzymes. Under NR-S:M conditions, early apoptotic events and the pro-apoptotic Bcl-xS/Bcl-xL ratio were found increased. NR-S:M induced the highest retention in cellular SubG1 phase, consistent with the presence of DNA fragments from cellular apoptosis. Mitochondrial functionality, Mitochondrial ATP-linked respiration, Maximal respiration and Spare respiratory capacity, were all found blunted under NR-S:M conditions. Basal Glycolysis, Glycolytic reserve, and glycolytic capacity, together with the expression of glycogenic (PKM), gluconeogenic (PCK1 and G6PC3), and glycogenolytic enzymes (PYGL, PGM1, and G6PC3), were also negatively impacted by NR-S:M. Lastly, a TMT-proteomic approach corroborated the synchronization of liver cancer metabolic reprogramming with the activation of molecular pathways to drive a quiescent-like status of energetic-collapse and cellular death.

CONCLUSION

Altogether, we show that the energy-based polytherapy NR-S:M blunts cellular, metabolic and molecular plasticity of liver cancer. Notwithstanding the in vitro design of this study, it holds a promising therapeutic tool worthy of exploration for this tumor pathology.

Glyoxalase 1: Emerging biomarker and therapeutic target in cervical cancer progression

INTRODUCTION

Cervical cancer presents a significant global health challenge, disproportionately impacting underserved populations with limited access to healthcare. Early detection and effective management are vital in addressing this public health concern. This study focuses on Glyoxalase-1 (GLO1), an enzyme crucial for methylglyoxal detoxification, in the context of cervical cancer.

METHODS

We assessed GLO1 expression in cervical cancer patient samples using immunohistochemistry. In vitro experiments using HeLa cells were conducted to evaluate the impact of GLO1 inhibition on cell viability and migration. Single-cell RNA sequencing (scRNA-seq) and gene set variation analysis were utilized to investigate the role of GLO1 in the metabolism of cervical cancer. Additionally, public microarray data were analyzed to determine GLO1 expression across various stages of cervical cancer.

RESULTS

Our analysis included 58 cervical cancer patients, and showed that GLO1 is significantly upregulated in cervical cancer tissues compared to normal cervical tissues, independent of pathological findings and disease stage. In vitro experiments indicated that GLO1 inhibition by S-p-bromobenzylglutathione cyclopentyl diester decreased cell viability and migration in cervical cancer cell lines. Analyses of scRNA-seq data and public gene expression datasets corroborated the overexpression of GLO1 and its involvement in cancer metabolism, particularly glycolysis. An examination of expression data from precancerous lesions revealed a progressive increase in GLO1 expression from normal tissue to invasive cervical cancer.

CONCLUSIONS

This study highlights the critical role of GLO1 in the progression of cervical cancer, presenting it as a potential biomarker and therapeutic target. These findings contribute valuable insights towards personalized treatment approaches and augment the ongoing efforts to combat cervical cancer. Further research is necessary to comprehensively explore GLO1's potential in clinical applications.

The Tumor Stroma of Squamous Cell Carcinoma: A Complex Environment That Fuels Cancer Progression

The tumor microenvironment (TME), a complex assembly of cellular and extracellular matrix (ECM) components, plays a crucial role in driving tumor progression, shaping treatment responses, and influencing metastasis. This narrative review focuses on the cutaneous squamous cell carcinoma (cSCC) tumor stroma, highlighting its key constituents and their dynamic contributions. We examine how significant changes within the cSCC ECM-specifically, alterations in fibronectin, hyaluronic acid, laminins, proteoglycans, and collagens-promote cancer progression, metastasis, and drug resistance. The cellular composition of the cSCC TME is also explored, detailing the intricate interplay of cancer-associated fibroblasts (CAFs), mesenchymal stem cells (MSCs), endothelial cells, pericytes, adipocytes, and various immune cell populations. These diverse players modulate tumor development, angiogenesis, and immune responses. Finally, we emphasize the TME's potential as a therapeutic target. Emerging strategies discussed in this review include harnessing the immune system (adoptive cell transfer, checkpoint blockade), hindering tumor angiogenesis, disrupting CAF activity, and manipulating ECM components. These approaches underscore the vital role that deciphering TME interactions plays in advancing cSCC therapy. Further research illuminating these complex relationships will uncover new avenues for developing more effective treatments for cSCC.

Stratification of tumour cell radiation response and metabolic signatures visualization with Raman spectroscopy and explainable convolutional neural network

Reprogramming of cellular metabolism is a driving factor of tumour progression and radiation therapy resistance. Identifying biochemical signatures associated with tumour radioresistance may assist with the development of targeted treatment strategies to improve clinical outcomes. Raman spectroscopy (RS) can monitor post-irradiation biomolecular changes and signatures of radiation response in tumour cells in a label-free manner. Convolutional Neural Networks (CNN) perform feature extraction directly from data in an end-to-end learning manner, with high classification performance. Furthermore, recently developed CNN explainability techniques help visualize the critical discriminative features captured by the model. In this work, a CNN is developed to characterize tumour response to radiotherapy based on its degree of radioresistance. The model was trained to classify Raman spectra of three human tumour cell lines as radiosensitive (LNCaP) or radioresistant (MCF7, H460) over a range of treatment doses and data collection time points. Additionally, a method based on Gradient-Weighted Class Activation Mapping (Grad-CAM) was used to determine response-specific salient Raman peaks influencing the CNN predictions. The CNN effectively classified the cell spectra, with accuracy, sensitivity, specificity, and F1 score exceeding 99.8%. Grad-CAM heatmaps of H460 and MCF7 cell spectra (radioresistant) exhibited high contributions from Raman bands tentatively assigned to glycogen, amino acids, and nucleic acids. Conversely, heatmaps of LNCaP cells (radiosensitive) revealed activations at lipid and phospholipid bands. Finally, Grad-CAM variable importance scores were derived for glycogen, asparagine, and phosphatidylcholine, and we show that their trends over cell line, dose, and acquisition time agreed with previously established models. Thus, the CNN can accurately detect biomolecular differences in the Raman spectra of tumour cells of varying radiosensitivity without requiring manual feature extraction. Finally, Grad-CAM may help identify metabolic signatures associated with the observed categories, offering the potential for automated clinical tumour radiation response characterization.

CLSPN actives Wnt/β-catenin signaling to facilitate glycolysis and cell proliferation in oral squamous cell carcinoma

OBJECTIVE

Oral squamous cell carcinoma (OSCC) is a common malignancy with a poor prognosis. This study aimed to determine the influence and underlying mechanisms of CLSPN on OSCC.

METHODS

CLSPN expression was tested using quantitative real-time polymerase chain reaction, immunohistochemistry, and western blotting. Flow cytometry, cell counting kit, and colony formation assays were performed to determine OSCC cell apoptosis, viability, and proliferation, respectively. In OSCC cells, the extracellular acidification rate (ECAR), oxygen consumption rate (OCR), glucose uptake, and lactate production were determined using the corresponding kits. Changes in the protein levels of HK2, PKM2, LDHA, Wnt3a, and β-catenin were assessed using western blotting.

RESULTS

CLSPN expression was increased in OSCC tissues. Overexpression of CLSPN in HSC-2 cells promoted cell proliferation, increased the levels of ECAR, glucose uptake, and lactate production, and increased the protein levels of HK2, PKM2, LDHA, Wnt3a, and β-catenin, but inhibited OCR levels and apoptosis. The knockdown of CLSPN in CAL27 cells resulted in the opposite results. Moreover, the effects of CLSPN overexpression on glycolysis and OSCC cell proliferation were reversed by Wnt3a knockdown. In vivo, knockdown of CLSPN restrained tumor growth, glycolysis, and the activation of Wnt/β-catenin signaling.

CONCLUSION

CLSPN promoted glycolysis and OSCC cell proliferation, and reduced apoptosis, which was achieved by the activation of Wnt/β-catenin signaling pathway.

PaSTe. Blockade of the Lipid Phenotype of Prostate Cancer as Metabolic Therapy: A Theoretical Proposal

BACKGROUND

Prostate cancer is the most frequently diagnosed malignancy in 112 countries and is the leading cause of death in eighteen. In addition to continuing research on prevention and early diagnosis, improving treatments and making them more affordable is imperative. In this sense, the therapeutic repurposing of low-cost and widely available drugs could reduce global mortality from this disease. The malignant metabolic phenotype is becoming increasingly important due to its therapeutic implications. Cancer generally is characterized by hyperactivation of glycolysis, glutaminolysis, and fatty acid synthesis. However, prostate cancer is particularly lipidic; it exhibits increased activity in the pathways for synthesizing fatty acids, cholesterol, and fatty acid oxidation (FAO).

OBJECTIVE

Based on a literature review, we propose the PaSTe regimen (Pantoprazole, Simvastatin, Trimetazidine) as a metabolic therapy for prostate cancer. Pantoprazole and simvastatin inhibit the enzymes fatty acid synthase (FASN) and 3-hydroxy-3-methylglutaryl- coenzyme A reductase (HMGCR), therefore, blocking the synthesis of fatty acids and cholesterol, respectively. In contrast, trimetazidine inhibits the enzyme 3-β-Ketoacyl- CoA thiolase (3-KAT), an enzyme that catalyzes the oxidation of fatty acids (FAO). It is known that the pharmacological or genetic depletion of any of these enzymes has antitumor effects in prostatic cancer.

RESULTS

Based on this information, we hypothesize that the PaSTe regimen will have increased antitumor effects and may impede the metabolic reprogramming shift. Existing knowledge shows that enzyme inhibition occurs at molar concentrations achieved in plasma at standard doses of these drugs.

CONCLUSION

We conclude that this regimen deserves to be preclinically evaluated because of its clinical potential for the treatment of prostate cancer.

Molecular mechanism of α-Hederin in tumor progression

α-Hederin is a monosaccharide pentacyclic triterpene saponin compound derived from the Chinese herb, Pulsatilla. It has garnered considerable attention for its anti-tumor, anti-inflammatory, and spasmolytic pharmacological activities. Given the rising incidence of cancer and the pronounced adverse reactions associated with chemotherapy drugs-which profoundly impact the quality of life for cancer patients-there is an immediate need for safe and effective antitumor agents. Traditional drugs and their anticancer effects have become a focal point of research in recent years. Studies indicate that α-Hederin can hinder tumor cell proliferation and impede the advancement of various cancers, including breast, lung, colorectal, and liver cancers. The principal mechanism behind its anti-tumor activity involves inhibiting tumor cell proliferation, facilitating tumor cell apoptosis, and arresting the cell cycle process. Current evidence suggests that α-Hederin can exert its anti-tumor properties through diverse mechanisms, positioning it as a promising agent in anti-tumor therapy. However, a comprehensive literature search revealed a gap in the comprehensive understanding of α-Hederin. This paper aims to review the available literature on the anti-tumor mechanisms of α-Hederin, hoping to provide valuable insights for the clinical treatment of malignant tumors and the innovation of novel anti-tumor medications.

Dual Implications of Nanosilver-Induced Autophagy: Nanotoxicity and Anti-Cancer Effects

In recent years, efforts have been made to identify new anti-cancer therapies. Various types of nanomaterials, including silver nanoparticles (AgNPs), are being considered as an option. In addition to its well-known antibacterial activity, AgNPs exhibit cytotoxic potential in both physiological and cancer cells by inducing stress-mediated autophagy and apoptotic cell death. A rapidly growing collection of data suggests that the proper regulation of autophagic machinery may provide an efficient tool for suppressing the development of cancer. In this light, AgNPs have emerged as a potential anti-cancer agent to support therapy of the disease. This review summarizes current data indicating the dual role of AgNP-induced autophagy and highlights factors that may influence its protective vs. its toxic potential. It also stresses that our understanding of the cellular and molecular mechanisms of autophagy machinery in cancer cells, as well as AgNP-triggered autophagy in both normal and diseased cells, remains insufficient.

Review of Patents for Anticancer Agents Targeting Adenosine Monophosphate-Activated Protein Kinase

Cancer, caused by abnormal and excessive cellular proliferation, can invade and destroy surrounding tissues and organs through the spreading of cancer cells. A general strategy for developing anticancer agents is to identify biomarkers that, if targeted, can produce a robust cytotoxic effect with minimal side effects. Cell-cycle regulators, checkpoint regulatory genes, and apoptosis-related genes are well-known biomarkers that inhibit cancer cell proliferation. Several compounds that target such biomarkers have been patented and more are being developed as novel therapies. Recent additions to this list include anticancer drugs that target signaling pathway proteins, such as 5' adenosine monophosphate-activated protein kinase (AMPK), which plays a vital role in cancer and normal cell metabolism. Herein, we have reviewed recent patents related to AMPK-targeting anticancer drugs and discussed the mechanisms of action of these drugs. We conclude that these recently published patents include several attractive compounds and methods for targeting AMPK. Further research and clinical trials are required to elucidate the comprehensive role of AMPK in cancer cell metabolism, identify its associated signal transduction systems, and develop novel activators that may find applications in cancer therapy. Clinical Trial Registration number: NCT01904123.

The role of tumor metabolism in modulating T-Cell activity and in optimizing immunotherapy

Immunotherapy has revolutionized cancer treatment and revitalized efforts to harness the power of the immune system to combat a variety of cancer types more effectively. However, low clinical response rates and differences in outcomes due to variations in the immune landscape among patients with cancer continue to be major limitations to immunotherapy. Recent efforts to improve responses to immunotherapy have focused on targeting cellular metabolism, as the metabolic characteristics of cancer cells can directly influence the activity and metabolism of immune cells, particularly T cells. Although the metabolic pathways of various cancer cells and T cells have been extensively reviewed, the intersections among these pathways, and their potential use as targets for improving responses to immune-checkpoint blockade therapies, are not completely understood. This review focuses on the interplay between tumor metabolites and T-cell dysfunction as well as the relationship between several T-cell metabolic patterns and T-cell activity/function in tumor immunology. Understanding these relationships could offer new avenues for improving responses to immunotherapy on a metabolic basis.

Chemical Biology Approaches to Identify and Profile Interactors of Chromatin Modifications

In eukaryotes, DNA is packaged with histone proteins in a complex known as chromatin. Both the DNA and histone components of chromatin can be chemically modified in a wide variety of ways, resulting in a complex landscape often referred to as the "epigenetic code". These modifications are recognized by effector proteins that remodel chromatin and modulate transcription, translation, and repair of the underlying DNA. In this Review, we examine the development of methods for characterizing proteins that interact with these histone and DNA modifications. "Mark first" approaches utilize chemical, peptide, nucleosome, or oligonucleotide probes to discover interactors of a specific modification. "Reader first" approaches employ arrays of peptides, nucleosomes, or oligonucleotides to profile the binding preferences of interactors. These complementary strategies have greatly enhanced our understanding of how chromatin modifications effect changes in genomic regulation, bringing us ever closer to deciphering this complex language.

Raman spectroscopy and convolutional neural networks for monitoring biochemical radiation response in breast tumour xenografts

Tumour cells exhibit altered metabolic pathways that lead to radiation resistance and disease progression. Raman spectroscopy (RS) is a label-free optical modality that can monitor post-irradiation biomolecular signatures in tumour cells and tissues. Convolutional Neural Networks (CNN) perform automated feature extraction directly from data, with classification accuracy exceeding that of traditional machine learning, in cases where data is abundant and feature extraction is challenging. We are interested in developing a CNN-based predictive model to characterize clinical tumour response to radiation therapy based on their degree of radiosensitivity or radioresistance. In this work, a CNN architecture is built for identifying post-irradiation spectral changes in Raman spectra of tumour tissue. The model was trained to classify irradiated versus non-irradiated tissue using Raman spectra of breast tumour xenografts. The CNN effectively classified the tissue spectra, with accuracies exceeding 92.1% for data collected 3 days post-irradiation, and 85.0% at day 1 post-irradiation. Furthermore, the CNN was evaluated using a leave-one-out- (mouse, section or Raman map) validation approach to investigate its generalization to new test subjects. The CNN retained good predictive accuracy (average accuracies 83.7%, 91.4%, and 92.7%, respectively) when little to no information for a specific subject was given during training. Finally, the classification performance of the CNN was compared to that of a previously developed model based on group and basis restricted non-negative matrix factorization and random forest (GBR-NMF-RF) classification. We found that CNN yielded higher classification accuracy, sensitivity, and specificity in mice assessed 3 days post-irradiation, as compared with the GBR-NMF-RF approach. Overall, the CNN can detect biochemical spectral changes in tumour tissue at an early time point following irradiation, without the need for previous manual feature extraction. This study lays the foundation for developing a predictive framework for patient radiation response monitoring.

IKCa channels control breast cancer metabolism including AMPK-driven autophagy

Ca²⁺-activated K⁺ channels of intermediate conductance (IK) are frequently overexpressed in breast cancer (BC) cells, while IK channel depletion reduces BC cell proliferation and tumorigenesis. This raises the question, of whether and mechanistically how IK activity interferes with the metabolic activity and energy consumption rates, which are fundamental for rapidly growing cells. Using BC cells obtained from MMTV-PyMT tumor-bearing mice, we show that both, glycolysis and mitochondrial ATP-production are reduced in cells derived from IK-deficient breast tumors. Loss of IK altered the sub-/cellular K⁺- and Ca²⁺- homeostasis and mitochondrial membrane potential, ultimately resulting in reduced ATP-production and metabolic activity. Consequently, we find that BC cells lacking IK upregulate AMP-activated protein kinase activity to induce autophagy compensating the glycolytic and mitochondrial energy shortage. Our results emphasize that IK by modulating cellular Ca²⁺- and K⁺-dynamics contributes to the remodeling of metabolic pathways in cancer. Thus, targeting IK channel might disturb the metabolic activity of BC cells and reduce malignancy.

Novel Thieno [2,3-b]pyridine Anticancer Compound Lowers Cancer Stem Cell Fraction Inducing Shift of Lipid to Glucose Metabolism

Due to the role of cancer stem cells (CSCs) in tumor resistance and glycosphingolipid (GSL) involvement in tumor pathogenesis, we investigated the effect of a newly synthesized compound (3-amino-N-(3-chloro-2-methylphenyl)-5-oxo-5,6,7,8-tetrahydrothieno[2,3-b]quinoline-2-carboxamide 1 on the percentage of CSCs and the expression of six GSLs on CSCs and non-CSCs on breast cancer cell lines (MDA-MB-231 and MCF-7). We also investigated the effect of 1 on the metabolic profile of these cell lines. The MTT assay was used for cytotoxicity determination. Apoptosis and expression of GSLs were assessed by flow cytometry. A GC–MS-coupled system was used for the separation and identification of metabolites. Compound 1 was cytotoxic for both cell lines, and the majority of cells died by treatment-induced apoptosis. The percentage of CSCs was significantly lower in the MDA-MB-231 cell line. Treatment with 1 caused a decrease of CSC IV⁶Neu₅Ac-nLc₄Cer+ MDA-MB-231 cells. In the MCF-7 cell line, the percentage of GalNAc-GM1b+ CSCs was increased, while the expression of Gg₃Cer was decreased in both CSC and non-CSC. Twenty-one metabolites were identified by metabolic profiling. The major impact of the treatment was in glycolysis/gluconeogenesis, pyruvate and inositol metabolism. Compound 1 exhibited higher potency in MBA-MB-231 cells, and it deserves further examination.

lncRNA CYTOR promotes aberrant glycolysis and mitochondrial respiration via HNRNPC-mediated ZEB1 stabilization in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC), the most common malignancy of the oral and maxillofacial region, severely affects human health. However, current treatments for OSCC commonly show only a ~60% 5-year survival rate of patients with distant metastases, indicating an urgent need for targeted treatments for patients with advanced metastases. Here, we report a survival-related long non-coding RNA, CYTOR, which is highly expressed in the lesions of oral cancer patients. We found that CYTOR can promote both migration and invasion in oral cancer cells as well as the epithelial-mesenchymal transition (EMT). RNA-sequencing of CYTOR-knockdown oral cancer cells revealed that CYTOR can regulate mitochondrial respiration and RNA splicing. Mechanistically, we found that nuclear-localized CYTOR interacts with HNRNPC, resulting in stabilization of ZEB1 mRNAs by inhibiting the nondegradative ubiquitination of HNRNPC. By synthesizing CYTOR-targeting small interfering RNAs (siRNAs) encapsulated in Nanoscale Metal Organic Frameworks (NMOFs), we demonstrate the targeted suppression of CYTOR to inhibit invasion and metastasis of oral cancer cells in a nude mouse model. Cumulatively, this study reveals the potential role of the CYTOR-HNRNPC-ZEB1 axis in regulating mitochondrial metabolism and glycolysis of oral cancer cells, and illustrates the effective use of lncRNA targeting in anti-metastatic cancer therapies.

Lactate Metabolism-Associated lncRNA Pairs: A Prognostic Signature to Reveal the Immunological Landscape and Mediate Therapeutic Response in Patients With Colon Adenocarcinoma

Background

Lactate metabolism is critically involved in the tumor microenvironment (TME), as well as cancer progression. It is important to note, however, that lactate metabolism-related long non-coding RNAs (laRlncRNAs) remain incredibly understudied in colon adenocarcinoma (COAD).

Methods

A gene expression profile was obtained from the Cancer Genome Atlas (TCGA) database to identify laRlncRNA expression in COAD patients. A risk signature with prognostic value was identified from TCGA and Gene Expression Omnibus (GEO) cohort based on laRlncRNA pairs by the least absolute shrinkage and selection operator (LASSO) and Cox regression analyses. Quantitative real-time polymerase chain reaction (qRT-PCR) and functional experiments were carried out to verify the expression of laRlncRNAs in COAD. The relationship of laRlncRNA pairs with immune landscape as well as the sensitivity of different therapies was explored.

Results

In total, 2378 laRlncRNAs were identified, 1,120 pairs of which were studied to determine their prognostic validity, followed by a risk signature established based on the screened 5 laRlncRNA pairs. The laRlncRNA pairs-based signature provided a better overall survival (OS) prediction than other published signatures and functioned as a prognostic marker for COAD patients. According to the calculated optimal cut-off point, patients were divided into high- and low-risk groups. The OS of COAD patients in the high-risk group were significantly shorter than that of those in the low-risk group (P=4.252e-14 in the TCGA cohort and P=2.865-02 in the GEO cohort). Furthermore, it remained an effective predictor of survival in strata of gender, age, TNM stage, and its significance persisted after univariate and multivariate Cox regressions. Additionally, the risk signature was significantly correlated with immune cells infiltration, tumor mutation burden (TMB), microsatellite instability (MSI) as well as immunotherapeutic efficacy and chemotherapy sensitivity. Finally, one of the laRlncRNA, LINC01315, promotes proliferation and migration capacities of colon cancer cells.

Conclusion

The newly identified laRlncRNAs pairs-based signature exhibits potential effects in predicting prognosis, deciphering patients’ immune landscape, and mediating sensitivity to immunotherapy and chemotherapy. Findings in our study may provide evidence for the role of laRlncRNAs pairs as novel prognostic biomarkers and potentially individualized therapy targets for COAD patients.

Arginase: Mechanisms and Clinical Application in Hematologic Malignancy

Compared to normal tissues and cells, the metabolic patterns of tumor illnesses are more complex, and there are hallmarks of metabolic reprogramming in energy metabolism, lipid metabolism, and amino acid metabolism. When tumor cells are in a state of fast growth, they are susceptible to food shortage, resulting in growth suppression. Using this metabolic sensitivity of tumor cells to construct amino acid consumption therapy does not harm the function of normal cells, which is the focus of metabolic therapy research at the moment. As a non-essential amino acid, arginine is involved in numerous crucial biological processes, including the signaling system, cell proliferation, and material metabolism. Rapidly dividing tumor cells are more likely to be deficient in arginine; hence, utilizing arginase to consume arginine can suppress tumor growth. Due to the absence of arginine succinate synthase, arginine succinate lyase, and ornithine carbamoyl transferase in some blood tumors, arginases may be employed to treat blood tumors. By investigating the mechanism of arginase treatment and the mechanism of drug resistance in greater depth, arginase treatment becomes more successful in hematological cancers and a new anti-cancer agent in clinical practice.

The Paracrine Effect of Hypoxic and Normoxic Cancer Secretion on the Proliferation of Brain Endothelial Cells (bEnd.3)

Background: This study aimed to investigate the disruption of cell cycle phases of bEnd.3 cells exposed to cancer paracrine secretion. Cancer cells have been reported to use the secretion of paracrine factors to compromise the endothelial barrier to prepare for their passage into the parenchyma. As cancer cells are known to act differently under conditions of hypoxia, we investigated how conditional media (CM) derived from breast and glioblastoma cells incubated under conditions of normoxia and hypoxia would affect proliferation of brain endothelial cells (bEnd.3). Methods: Brain endothelial cells (bEnd.3) were cultivated with normoxic and hypoxic CM generated from breast cancer MCF7 cells and glioblastoma U-87 cells. Cell proliferation was evaluated using the trypan blue exclusion assay and phases of the cell cycle were evaluated using flow cytometry. Results: bEnd.3 proliferations was suppressed more aggressively with hypoxic CM after 72 and 96 h; cell cycle analysis showed that paracrine treatment tended to prevent BECs from entering the G2 phase, thus suppressing cell division. Conclusions: MCF7 and U-87 cells induce suppressed proliferation of BECs deferentially under hypoxia by blocking cell cycle progression to the G2 phase.

Cocktail strategy based on a dual function nanoparticle and immune activator for effective tumor suppressive

Background

Immune checkpoint inhibitor-mediated immunotherapy cannot be carried out on a large scale clinically due to its low universality. In recent years, cyclic guanosine monophosphate synthase/interferon gene stimulating factor (cGAS/STING)-mediated innate immune signaling pathway-mediated immunotherapy has attracted more and more attention. In addition, metabolic inhibitors also show good effects on tumor treatment, but their application is often limited because of their large first pass effect or difficult administration.

Methods

The particle size and potential parameters were measured by DLS. In order to determine the optimal ratio of the two drugs, we calculated the CI value of different nanoparticles through MTT experiment, and simulated their synergistic effect through Gaussian software. Then the morphology and crystal form of the best proportion of drugs were studied by TEM and XRD. The anti-tumor mechanism of composite nanoparticles was confirmed by the determination of metabolic related indexes, Q-PCR and WB. The antitumor effect and immune activation effect were comprehensively evaluated by in vivo and in vitro experiments.

Results

Here, we found and synthesized BCP nanoparticles ((BPA + CPI) @ PLGA NPs) which can effectively reduce the metabolism of tumor cells and inhibit cell proliferation. At the same time, the release of mitochondrial DNA (mtDNA) caused by mitochondrial metabolism disorder further activated the cGAS/STING signal pathway in Hepa1–6 cells. We found that the drug-treated Hepa1–6 cells had obvious TBK1 phosphorylation and STING dimerization. Combined with STING agonist, it could effectively promote the activation of CD8 T cells and enhanced the therapeutic effect on liver cancer.

Conclusion

Our results showed that PLGA nanocarrier can successfully improve the dosage forms of two metabolic inhibitors and show the effect of synergistic therapy. BCP nanoparticles can also activate the innate immunity of tumor cells and significantly enhance tumor inhibition after combined with STING agonists. This study has high reference and transformation value for the combined treatment of immunosuppression and metabolic inhibition.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-022-01241-y.

1H -NMR Metabolomics Study of the Effect of Cisplatin and Casiopeina IIgly on MDA-MB-231 Breast Tumor Cells

The knowledge of the metabolic processes of designed metallodrugs for cancer treatment is an area that has been not profoundly studied. Casiopeina IIgly (CasIIgly), which belongs to the Casiopeínas^® family, is a copper (II) coordination compound that has shown good biological activity against several cancer cells, low toxicity in normal cells, and antineoplastic activity in in vivo murine and xenografted models. In this work we employed a triple-negative highly metastatic breast carcinoma line (MDA-MB-231), which is one of the cancer types with a great mortality index, for ¹H-NMR metabolomic analysis using cisplatin and CasIIgly, in order to quantify the effect of metallodrugs in the metabolic profile of this cell tumor line as a consequence of treatment at different times. Our findings indicate that cisplatin mainly contributes to phospholipid biosynthesis while CasIIgly affects processes such as carbohydrates and nucleotides metabolism. Also, we observed that CasIIgly treatment has an important and fast effect over MDA-MB-231 cell metabolism, which makes it a good alternative for treatment in this type of cancer.

α-Hederin inhibits the growth of lung cancer A549 cells in vitro and in vivo by decreasing SIRT6 dependent glycolysis

CONTEXT

α-Hederin, a potent bioactive compound of Pulsatilla chinensis (Bunge) Regel (Ranunculaceae), has many pharmacological uses, but its effect on cancer cell metabolism is still unclear.

OBJECTIVE

To elucidate the role of α-hederin in the glucose metabolism of lung cancer cells.

MATERIALS AND METHODS

Cell Counting Kit 8 and colony formation assays were employed to assess the antiproliferative effects of α-hederin. Glucose uptake, ATP generation, and lactate production were measured. Glycolysis-related proteins were detected using western blotting, and a sirtuin 6 (SIRT6) inhibitor was used to verify A549 cell proliferation. Sixty male BALB/c nude mice were divided into normal control, 5-FU (25 mg/kg), and α-hederin (5 and 10 mg/kg) groups to assess the antitumor effect for 32 days. Glycolysis-related protein expression was evaluated using immunohistochemical analysis.

RESULTS

α-Hederin inhibited A549 (IC₅₀ = 13.75 μM), NCI-H460 (IC₅₀ = 17.57 μM), and NCI-H292 (IC₅₀ = 18.04 μM) proliferation; inhibited glucose uptake and ATP generation; and reduced lactate production. Furthermore, α-hederin (10 and 15 μM) markedly inhibited hexokinase 2, glucose transporter 1, pyruvate kinase M2, lactate dehydrogenase A, monocarboxylate transporter, c-Myc, hypoxia-inducible factor-1α, and activated SIRT6 protein expression. Using a SIRT6 inhibitor, we demonstrated that α-hederin inhibits glycolysis by activating SIRT6. A tumour xenograft mouse model of lung cancer confirmed that α-hederin (5 and 10 mg/kg) inhibits lung cancer growth by inhibiting glycolysis in vivo.

DISCUSSION AND CONCLUSIONS

α-Hederin inhibits A549 cell growth by inhibiting SIRT6-dependent glycolysis. α-Hederin might serve as a potential agent to suppress cancer.

Non-invasive, label-free optical analysis to detect aneuploidy within the inner cell mass of the preimplantation embryo

STUDY QUESTION

Can label-free, non-invasive optical imaging by hyperspectral autofluorescence microscopy discern between euploid and aneuploid cells within the inner cell mass (ICM) of the mouse preimplantation embryo?

SUMMARY ANSWER

Hyperspectral autofluorescence microscopy enables discrimination between euploid and aneuploid ICM in mouse embryos.

WHAT IS KNOWN ALREADY

Euploid/aneuploid mosaicism affects up to 17.3% of human blastocyst embryos with trophectoderm biopsy or spent media currently utilized to diagnose aneuploidy and mosaicism in clinical in vitro fertilization. Based on their design, these approaches will fail to diagnose the presence or proportion of aneuploid cells within the foetal lineage ICM of some blastocyst embryos.

STUDY DESIGN, SIZE, DURATION

The impact of aneuploidy on cellular autofluorescence and metabolism of primary human fibroblast cells and mouse embryos was assessed using a fluorescence microscope adapted for imaging with multiple spectral channels (hyperspectral imaging). Primary human fibroblast cells with known ploidy were subjected to hyperspectral imaging to record native cell fluorescence (4-6 independent replicates, euploid n = 467; aneuploid n = 969). For mouse embryos, blastomeres from the eight-cell stage (five independent replicates: control n = 39; reversine n = 44) and chimeric blastocysts (eight independent replicates: control n = 34; reversine n = 34; 1:1 (control:reversine) n = 30 and 1:3 (control:reversine) n = 37) were utilized for hyperspectral imaging. The ICM from control and reversine-treated embryos were mechanically dissected and their karyotype confirmed by whole genome sequencing (n = 13 euploid and n = 9 aneuploid).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Two models were employed: (i) primary human fibroblasts with known karyotype and (ii) a mouse model of embryo aneuploidy where mouse embryos were treated with reversine, a reversible spindle assembly checkpoint inhibitor, during the four- to eight-cell division. Individual blastomeres were dissociated from control and reversine-treated eight-cell embryos and either imaged directly or used to generate chimeric blastocysts with differing ratios of control:reversine-treated cells. Individual blastomeres and embryos were interrogated by hyperspectral imaging. Changes in cellular metabolism were determined by quantification of metabolic co-factors (inferred from their autofluorescence signature): NAD(P)H and flavins with the subsequent calculation of the optical redox ratio (ORR: flavins/[NAD(P)H + flavins]). Autofluorescence signals obtained from hyperspectral imaging were examined mathematically to extract features from each cell/blastomere/ICM. This was used to discriminate between different cell populations.

MAIN RESULTS AND THE ROLE OF CHANCE

An increase in the relative abundance of NAD(P)H and decrease in flavins led to a significant reduction in the ORR for aneuploid cells in primary human fibroblasts and reversine-treated mouse blastomeres (P < 0.05). Mathematical analysis of endogenous cell autofluorescence achieved separation between (i) euploid and aneuploid primary human fibroblast cells, (ii) control and reversine-treated mouse blastomeres cells, (iii) control and reversine-treated chimeric blastocysts, (iv) 1:1 and 1:3 chimeric blastocysts and (v) confirmed euploid and aneuploid ICM from mouse blastocysts. The accuracy of these separations was supported by receiver operating characteristic curves with areas under the curve of 0.97, 0.99, 0.87, 0.88 and 0.93, respectively. We believe that the role of chance is low as mathematical features separated euploid from aneuploid in both human fibroblasts and ICM of mouse blastocysts.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

Although we were able to discriminate between euploid and aneuploid ICM in mouse blastocysts, confirmation of this approach in human embryos is required. While we show this approach is safe in mouse, further validation is required in large animal species prior to implementation in a clinical setting.

WIDER IMPLICATIONS OF THE FINDINGS

We have developed an original, accurate and non-invasive optical approach to assess aneuploidy within the ICM of mouse embryos in the absence of fluorescent tags. Hyperspectral autofluorescence imaging was able to discriminate between euploid and aneuploid human fibroblast and mouse blastocysts (ICM). This approach may potentially lead to a new diagnostic for embryo analysis.

STUDY FUNDING/COMPETING INTEREST(S)

K.R.D. is supported by a Mid-Career Fellowship from the Hospital Research Foundation (C-MCF-58-2019). This study was funded by the Australian Research Council Centre of Excellence for Nanoscale Biophotonics (CE140100003) and the National Health and Medical Research Council (APP2003786). The authors declare that there is no conflict of interest.

OxLDL as an Inducer of a Metabolic Shift in Cancer Cells

Recent evidence established a link between disturbed lipid metabolism and increased risk for cancer. One of the most prominent features related to disturbed lipid metabolism is an increased production of oxidized low-density-lipoproteins (oxLDL), which results from elevated oxidative stress. OxLDL is known to have detrimental effects on healthy cells and plays a primary role in diseases related to the metabolic syndrome. Nevertheless, so far, the exact role of oxLDL in cancer cell metabolism is not yet known. To examine changes in metabolic profile induced by oxLDL, pancreatic KLM-1 cells were treated with oxLDL in a concentration- (25 or 50 µg/ml) and/or time-dependent (4 hr or 8 hr) manner and the impact of oxLDL on oxygen consumption rates (OCR) as well as extracellular acidification rates (ECAR) was analyzed using Seahorse technology. Subsequently, to establish the link between oxLDL and glycolysis, stabilization of the master regulator hypoxia-inducible factor 1-alpha (HIF-1α) was measured by means of Western blot. Furthermore, autophagic responses were assessed by measuring protein levels of the autophagosomal marker LC3B-II. Finally, the therapeutic potential of natural anti-oxLDL IgM antibodies in reversing these effects was tested. Incubation of KLM-1 cells with oxLDL shifted the energy balance towards a more glycolytic phenotype, which is an important hallmark of cancer cells. These data were supported by measurement of increased oxLDL-mediated HIF-1α stabilization. In line, oxLDL incubation also increased the levels of LC3B-II, suggesting an elevated autophagic response. Importantly, antibodies against oxLDL were able to reverse these oxLDL-mediated metabolic effects. Our data provides a novel proof-of-concept that oxLDL induces a shift in energy balance. These data not only support a role for oxLDL in the progression of cancer but also suggest the possibility of targeting oxLDL as a therapeutic option in cancer.

Targeting Signalling Cross-Talk between Cancer Cells and Cancer-Associated Fibroblast through Monocarboxylate Transporters in Head and Neck Cancer

Head and Neck Squamous Cell Carcinoma (HNSCC) is an aggressive malignancy affecting more than 600,000 cases worldwide annually, associated with poor prognosis and significant morbidity. HNSCC tumors are dysplastic, with up to 80% fibroblasts. It has been reported that Cancer-Associated Fibroblasts (CAFs) facilitate HNSCC progression. Unlike normal cells, malignant cells often display increased glycolysis, even in the presence of oxygen; a phenomenon known as the Warburg effect. As a consequence, there is an increase in Lactic Acid (LA) production. Earlier, it has been reported that HNSCC tumors exhibit high LA levels that correlate with reduced survival. It has been reported that the activation of the receptor tyrosine kinase, c- MET, by CAF-secreted Hepatocyte Growth Factor (HGF) is a major contributing event in the progression of HNSCC. In nasopharyngeal carcinoma, c-MET inhibition downregulates the TP53-Induced Glycolysis and Apoptosis Regulator (TIGAR) and NADPH production resulting in apoptosis. Previously, it was demonstrated that HNSCC tumor cells are highly glycolytic. Further, CAFs show a higher capacity to utilize LA as a carbon source to fuel mitochondrial respiration than HNSCC. Earlier, we have reported that in admixed cultures, both cell types increase the expression of Monocarboxylate Transporters (MCTs) for a bidirectional LA transporter. Consequently, MCTs play an important role in signalling cross-talk between cancer cells and cancer associate fibroblast in head and neck cancer, and targeting MCTs would lead to the development of a potential therapeutic approach for head and neck cancer. In this review, we focus on the regulation of MCTs in head and neck cancer through signalling cross-talk between cancer cells and cancer-associated fibroblasts, and targeting this signalling cross talk would lead to the development of a potential therapeutic approach for head and neck cancer.

Cerebrospinal fluid lipidomics for biomarkers of Alzheimer's disease

Alzheimer's disease (AD) is the most common cause of dementia and is associated with serious neurologic sequelae resulting from neurodegenerative changes. Identification of markers of early-stage AD could be important for designing strategies to arrest the progression of the disease. The brain is rich in lipids because they are crucial for signal transduction and anchoring of membrane proteins. Cerebrospinal fluid (CSF) is an excellent specimen for studying the metabolism of lipids in AD because it can reflect changes occurring in the brain. We aimed to identify CSF lipidomic alterations associated with AD, using untargeted lipidomics, carried out in positive and negative ion modes. We found CSF lipids that were significantly altered in AD cases. In addition, comparison of CSF lipid profiles between persons with mild cognitive impairment (MCI) and AD showed a strong positive correlation between the lipidomes of the MCI and AD groups. The novel lipid biomarkers identified in this study are excellent candidates for validation in a larger set of patient samples and as predictive biomarkers of AD through future longitudinal studies. Once validated, the lipid biomarkers could lead to early detection, disease monitoring and the ability to measure the efficacy of potential therapeutic interventions in AD.

Interfering with Metabolic Profile of Triple-Negative Breast Cancers Using Rationally Designed Metformin Prodrugs

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer, characterized by an aberrant metabolic phenotype with high metastatic capacity, resulting in poor patient prognoses and low survival rates. We designed a series of novel Au^III cyclometalated prodrugs of energy-disrupting Type II antidiabetic drugs namely, metformin and phenformin. Prodrug activation and release of the metformin ligand was achieved by tuning the cyclometalated Au^III fragment. The lead complex 3met was 6000-fold more cytotoxic compared to uncoordinated metformin and significantly reduced tumor burden in mice with aggressive breast cancers with lymphocytic infiltration into tumor tissues. These effects was ascribed to 3met interfering with energy production in TNBCs and inhibiting associated pro-survival responses to induce deadly metabolic catastrophe.

Inositol treatment inhibits medulloblastoma through suppression of epigenetic-driven metabolic adaptation

Deregulation of chromatin modifiers plays an essential role in the pathogenesis of medulloblastoma, the most common paediatric malignant brain tumour. Here, we identify a BMI1-dependent sensitivity to deregulation of inositol metabolism in a proportion of medulloblastoma. We demonstrate mTOR pathway activation and metabolic adaptation specifically in medulloblastoma of the molecular subgroup G4 characterised by a BMI1High;CHD7Low signature and show this can be counteracted by IP6 treatment. Finally, we demonstrate that IP6 synergises with cisplatin to enhance its cytotoxicity in vitro and extends survival in a pre-clinical BMI1High;CHD7Low xenograft model.

Role of Warburg Effect in Cardiovascular Diseases: A Potential Treatment Option

Background:

Under normal conditions, the heart obtains ATP through the oxidation of fatty acids, glucose, and ketones. While fatty acids are the main source of energy in the heart, under certain conditions, the main source of energy shifts to glucose where pyruvate converts into lactate, to meet the energy demand. The Warburg effect is the energy shift from oxidative phosphorylation to glycolysis in the presence of oxygen. This effect is observed in tumors as well as in diseases, including cardiovascular diseases. If glycolysis is more dominant than glucose oxidation, the two pathways uncouple, contributing to the severity of the heart condition. Recently, several studies have documented changes in metabolism in several cardiovascular diseases; however, the specific mechanisms remain unclear.

Methods:

This literature review was conducted by an electronic database of Pub Med, Google Scholar, and Scopus published until 2020. Relevant papers are selected based on inclusion and exclusion criteria.

Results:

A total of 162 potentially relevant articles after the title and abstract screening were screened for full-text. Finally, 135 papers were included for the review article.

Discussion:

This review discusses the effects of alterations in glucose metabolism, particularly the Warburg effect, on cardiovascular diseases, including heart failure, atrial fibrillation, and cardiac hypertrophy.

Conclusion:

Reversing the Warburg effect could become a potential treatment option for cardiovascular diseases.

Raman spectroscopy and group and basis-restricted non negative matrix factorisation identifies radiation induced metabolic changes in human cancer cells

This work combines single cell Raman spectroscopy (RS) with group and basis restricted non-negative matrix factorisation (GBR-NMF) to identify individual biochemical changes associated with radiation exposure in three human cancer cell lines. The cell lines analysed were derived from lung (H460), breast (MCF7) and prostate (LNCaP) tissue and are known to display varying degrees of radio sensitivity due to the inherent properties of each cell type. The GBR-NMF approach involves the deconstruction of Raman spectra into component biochemical bases using a library of Raman spectra of known biochemicals present in the cells. Subsequently, scores are obtained on each of these bases which can be directly correlated with the contribution of each chemical to the overall Raman spectrum. We validated GBR-NMF through the correlation of GBR-NMF-derived glycogen scores with scores that were previously observed using principal component analysis (PCA). Phosphatidylcholine, glucose, arginine and asparagine showed a distinct differential score pattern between radio-resistant and radio-sensitive cell types. In summary, the GBR-NMF approach allows for the monitoring of individual biochemical radiation-response dynamics previously unattainable with more traditional PCA-based approaches.

Memantine shifts cancer cell metabolism via AMPK1/2 mediated energetic switch in A549 lung cancer cells

Memantine is used to prevent glutamate-mediated excitotoxicity and neurodegeneration in Alzheimer's disease. As glutamine is one of the major source of anabolism in fast growing cancer cells, we aimed to interfere with the cancer cell metabolism in A549 lung cancer cells by using memantine. The effects of memantine on cell cycle progression and cell death in A549 cells were assessed by MTT assay and PI staining. Cells were treated with 0.25 mM memantine for 48 hours and then cell metabolism (AMPKA1, AMPKA2, HIF1A, B-catenin, PKM), apoptosis (p53, p21, Bax, Bcl-XL, NOXA, PUMA) and autophagy related (LC3B-I, LC3B-II, SQSTM1) mRNA and protein expressions were investigated by RT-qPCR and western blotting. Memantine decreased cell viability significantly in a concentration-dependent manner by inducing G0/G1 cell cycle arrest. Our results suggest that memantine activates AMPK1/2 significantly (p=0.039 and p=0.0105) that led cells through apoptosis and autophagy by decreasing cancer cell metabolism regulators like HIF1A, B-catenin and PKM as the consequence of this energetic shift. Memantine represents a useful tool to target metabolism in cancer cells. Therefore, it might be used a new repurposed drug in cancer treatment.

Fucoidan Structure and Its Impact on Glucose Metabolism: Implications for Diabetes and Cancer Therapy

Fucoidans are complex polysaccharides derived from brown seaweeds which consist of considerable proportions of L-fucose and other monosaccharides, and sulphated ester residues. The search for novel and natural bioproduct drugs (due to toxicity issues associated with chemotherapeutics) has led to the extensive study of fucoidan due to reports of it having several bioactive characteristics. Among other fucoidan bioactivities, antidiabetic and anticancer properties have received the most research attention in the past decade. However, the elucidation of the fucoidan structure and its biological activity is still vague. In addition, research has suggested that there is a link between diabetes and cancer; however, limited data exist where dual chemotherapeutic efforts are elucidated. This review provides an overview of glucose metabolism, which is the central process involved in the progression of both diseases. We also highlight potential therapeutic targets and show the relevance of fucoidan and its derivatives as a candidate for both cancer and diabetes therapy.

An 18-gene signature based on glucose metabolism and DNA methylation improves prognostic prediction for urinary bladder cancer

BACKGROUND

Glucose metabolism and DNA methylation play important roles in cancers. We aimed to identify glucose metabolism-related genes that were DNA methylation associated to establish a prognostic signature of bladder cancer (BLCA).

METHODS

With BLCA sample transcriptome data from The Cancer Genome Atlas (TCGA) and methylation data from TCGA 450 K microarray, glucose metabolism-related genes associated to prognosis and DNA methylation were identified and a prognostic signature was established. GSEA and WGCNA analysis were performed and two genes, UCHL1 and PYCR1, were selected for functional validations.

RESULTS

18 target genes were identified and the signature based on them was considered an effective and independent prognostic factor. Several pathways were enriched in the high-risk group by GSEA and three modules of genes were identified by WGCNA. UCHL1 and PYCR1 proliferated proliferation, migration and invasion ability of bladder cancer cells.

CONCLUSIONS

The 18-gene signature is an independent prognostic factor for bladder cancer patients.

A Novel Seventeen-Gene Metabolic Signature for Predicting Prognosis in Colon Cancer

A metabolic disorder is considered one of the hallmarks of cancer. Multiple differentially expressed metabolic genes have been identified in colon cancer (CC), and their biological functions and prognostic values have been well explored. The purpose of the present study was to establish a metabolic signature to optimize the prognostic prediction in CC. The related data were downloaded from The Cancer Genome Atlas (TCGA), Genotype-Tissue Expression (GTEx) database, and Gene Expression Omnibus (GEO) combined with GSE39582 set, GSE17538 set, GSE33113 set, and GSE37892 set. The differentially expressed metabolic genes were selected for univariate Cox regression and lasso Cox regression analysis using TCGA and GTEx datasets. Finally, a seventeen-gene metabolic signature was developed to divide patients into a high-risk group and a low-risk group. Patients in the high-risk group presented poorer prognosis compared to the low-risk group in both TCGA and GEO datasets. Moreover, gene set enrichment analyses demonstrated multiple significantly enriched metabolism-related pathways. To sum up, our study described a novel seventeen-gene metabolic signature for prognostic prediction of colon cancer.

Lactic Acid and an Acidic Tumor Microenvironment suppress Anticancer Immunity

Immune evasion and altered metabolism, where glucose utilization is diverted to increased lactic acid production, are two fundamental hallmarks of cancer. Although lactic acid has long been considered a waste product of this alteration, it is now well accepted that increased lactic acid production and the resultant acidification of the tumor microenvironment (TME) promotes multiple critical oncogenic processes including angiogenesis, tissue invasion/metastasis, and drug resistance. We and others have hypothesized that excess lactic acid in the TME is responsible for suppressing anticancer immunity. Recent studies support this hypothesis and provide mechanistic evidence explaining how lactic acid and the acidic TME impede immune cell functions. In this review, we consider lactic acid’s role as a critical immunoregulatory molecule involved in suppressing immune effector cell proliferation and inducing immune cell de-differentiation. This results in the inhibition of antitumor immune responses and the activation of potent, negative regulators of innate and adaptive immune cells. We also consider the role of an acidic TME in suppressing anticancer immunity. Finally, we provide insights to help translate this new knowledge into impactful anticancer immune therapies.

Regulation of Glycolysis by Non-coding RNAs in Cancer: Switching on the Warburg Effect

The “Warburg effect” describes the reprogramming of glucose metabolism away from oxidative phosphorylation toward aerobic glycolysis, and it is one of the hallmarks of cancer cells. Several factors can be involved in this process, but in this review, the roles of non-coding RNAs (ncRNAs) are highlighted in several types of human cancer. ncRNAs, including microRNAs, long non-coding RNAs, and circular RNAs, can all affect metabolic enzymes and transcription factors to promote glycolysis and modulate glucose metabolism to enhance the progression of tumors. In particular, the 5′-AMP-activated protein kinase (AMPK) and the phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathways are associated with alterations in ncRNAs. A better understanding of the roles of ncRNAs in the Warburg effect could ultimately lead to new therapeutic approaches for suppressing cancer.

LC-MS based stability-indicating method for studying the degradation of lonidamine under physical and chemical stress conditions

Background and purpose:

Lonidamine is a hexokinase II inhibitor, works as an anticancer molecule, and is extensively explored in clinical trials. Limited information prevails about the stability-indicating methods which could determine the forced degradation of lonidamine under stressed conditions. Hence, we report the use of a rapid, sensitive, reproducible, and highly accurate liquid chromatography and mass spectrometry method to analyze lonidamine degradation.

Experimental approach:

The Xbridge BEH shield reverse phase C18 column (2.5 μm, 4.6 × 75 mm) using isocratic 50:50 water: acetonitrile with 0.1% formic acid can detect lonidamine with help of mass spectrometer in tandem with an ultraviolet (UV) detector at 260 nm wavelength.

Findings/ Results:

A linear curve with r² > 0.99 was obtained for tandem liquid chromatography-mass spectrometry (LC-MS)-UV based detections. This study demonstrated (in the present set up of isocratic elution) that LC-MS based detection has a relatively high sensitivity (S/N (10 ng/mL): 220 and S/N (20 ng/mL): 945) and accuracy at lower detection and quantitation levels, respectively. In addition to developing the LC-MS method, we also report that the current method is stability-indicating and shows that lonidamine gets degraded over time under all three stress conditions; acidic, basic, and oxidative.

Conclusion and implications:

LC-MS based quantitation of lonidamine proved to be a better method compared to high-performance liquid chromatography (HPLC)-UV detections for mapping lonidamine degradation. This is the first report on the stability-indicating method for studying the forced degradation of lonidamine using LC-MS method.

From Warburg effect to Reverse Warburg effect; the new horizons of anti-cancer therapy

An old ideology of killing the cancer cells by starving them is the underlying concept of the Warburg effect. It is the process of aerobic glycolysis exhibited by the cancer cells irrespective of anaerobic glycolysis or mitochondrial oxidative phosphorylation following by their healthy counterparts. Dr Otto Heinrich Warburg proposed this abnormal metabolic behaviour of tumour cells in 1920. This phenomenon illustrates the metabolic switching in tumour cells from oxidative phosphorylation to aerobic glycolysis triggered by an injury to the mitochondrial respiration. A modernised perspective of the Warburg hypothesis termed the Reverse Warburg effect introduced in 2009, with a two-compartment model describing the metabolic symbiosis between cancer cells and its neighbouring stromal cells or cancer-associated fibroblasts. This theory is elucidating the aerobic glycolysis occurring in cancer-associated fibroblasts which leads to the generation and deposition of the lactate in tumour microenvironment along with its significance. The transportation of lactate to and from the cancer cell and extracellular space is facilitated by the lactate transporters called monocarboxylate transporters. This lactate generated irrespective of the hypoxic or aerobic conditions acts as a primary metabolic fuel for the cancer cells. Besides, it will create a tumour microenvironment that is favouring the progression and metastasis of malignancy through several means. Overall, the lactate produced through this metabolic reprogramming is supporting and worsening the conditions of cancer. The concept of the Reverse Warburg effect proposes a new anti-cancer treatment modality by preventing the generation and transport of lactate through the inhibition of monocarboxylate transporters and in turn, defeating the cancer disease by arresting the cancer cells along with silencing tumour microenvironment.

Mitochondrial chaperone, TRAP1 modulates mitochondrial dynamics and promotes tumor metastasis

Mitochondria play a central role in regulating cellular energy metabolism. However, the present understanding of mitochondria has changed from its unipotent functions to pluripotent and insists on understanding the role of mitochondria not only in regulating the life and death of cells, but in pathological conditions such as cancer. Unlike other cellular organelles, subtle alterations in mitochondrial organization may significantly influence the balance between metabolic networks and cellular behavior. Therefore, the delicate balance between the fusion and fission dynamics of mitochondrion can indicate cell fate. Here, we present mitochondrial chaperone TRAP1 influence on mitochondrial architecture and its correlation with tumor growth and metastasis. We show that TRAP1 overexpression (TRAP1 OE) promotes mitochondrial fission, whereas, TRAP1 knockdown (TRAP1 KD) promotes mitochondrial fusion. Interestingly, TRAP1 OE or KD had a negligible effect on mitochondrial integrity. However, TRAP1 OE cells exhibited enhanced proliferative potential, while TRAP1 KD cells showing increased doubling time. Further, TRAP1 dependent mitochondrial dynamic alterations appeared to be unique since mitochondrial localization of TRAP1 is a mandate for dynamic changes. The expression patterns of fusion and fission genes have failed to correlate with TRAP1 expression, indicating a possibility that the dynamic changes can be independent of these genes. In agreement with enhanced proliferative potential, TRAP1 OE cells also exhibited enhanced migration in vitro and tumor metastasis in vivo. Further, TRAP1 OE cells showed altered homing properties, which may challenge site-specific anticancer treatments. Our findings unravel the TRAP1 role in tumor metastasis, which is in addition to altered energy metabolism.

The role of CA-125, GLS and FASN in predicting cytoreduction for epithelial ovarian cancers

OBJECTIVE

Cytoreduction has an important role in improving the survival rate of epithelial ovarian cancer (EOC) patients. This study aimed to assess the ability of preoperative serum CA125, FASN and GLS as predictors of cytoreductive surgery for epithelial ovarian cancer (EOC).

RESULTS

The average values of serum CA-125, FASN, and GLS in the suboptimal cytoreduction group were higher than those in optimal cytoreduction group. The cut off point (COP) was 248.55 (p = 0.0001) with 73.2% sensitivity and 73.6% specificity for CA-125, 0.445 (p = 0.017) with 62.5% sensitivity and 60.4% specificity for FASN, and 22.895 (p = 0.0001) with 73.2% sensitivity and 75.5% specificity for GLS. The COP of CA-125 and GLS combined was 29.16 (p = 0.0001) with sensitivity 82.1% and specificity 73.6%, while the COP of CA-125, GLS, and FASN combined was 0.83 (p = 0.0001) with 87.5% sensitivity and 73.6% specificity.

Cellular Mechanisms of Circulating Tumor Cells During Breast Cancer Metastasis

Circulating tumor cells (CTCs) are cancer cells that detach from the primary site and travel in the blood stream. A higher number of CTCs increases the risk of breast cancer metastasis, and it is inversely associated with the survival rates of patients with breast cancer. Although the numbers of CTCs are generally low and the majority of CTCs die in circulation, the survival of a few CTCs can seed the development of a tumor at a secondary location. An increasing number of studies demonstrate that CTCs undergo modification in response to the dynamic biophysical environment in the blood due in part to fluid shear stress. Fluid shear stress generates reactive oxygen species (ROS), triggers redox-sensitive cell signaling, and alters the function of intracellular organelles. In particular, the mitochondrion is an important target organelle in determining the metastatic phenotype of CTCs. In healthy cells, mitochondria produce adenosine triphosphate (ATP) via oxidative phosphorylation in the electron transport chain, and during oxidative phosphorylation, they produce physiological levels of ROS. Mitochondria also govern death mechanisms such as apoptosis and mitochondrial permeability transition pore opening to, in order eliminate unwanted or damaged cells. However, in cancer cells, mitochondria are dysregulated, causing aberrant energy metabolism, redox homeostasis, and cell death pathways that may favor cancer invasiveness. In this review, we discuss the influence of fluid shear stress on CTCs with an emphasis on breast cancer pathology, then discuss alterations of cellular mechanisms that may increase the metastatic potentials of CTCs.

The metabolic role of PFKFB4 in androgen-independent growth in vitro and PFKFB4 expression in human prostate cancer tissue

Background

It is well known that androgen-deprivation therapy (ADT) can inevitably drive prostate cancer (PCa) cells into a castration-resistant state. According to the “Warburg effect”, the metabolism of aggressive tumor cells increases significantly. The growth of cancer cells depends on glycolysis, which may be a potential target for cancer control. 6-Phosphofructo-2-kinase/fructose-2,6-biphosphatase 4 (PFKFB4) plays key roles in the proliferation and metastasis of PCa cells. However, there is very limited knowledge on the role of PFKFB4 in the conversion to castration resistance. The present study aimed to determine the changes in glucose consumption and PFKFB4 expression in LNCaP cells and androgen-independent LNCaP (LNCaP-AI) cells during the whole process of androgen-independent growth. Additionally, PFKFB4 expression in human PCa tissues was evaluated.

Methods

We established an androgen-independent LNCaP-AI cell line derived from LNCaP cells to mimic the traits of castration resistance in vitro. LNCaP-AI and LNCaP cells were cultured in the corresponding medium containing the same amount of glucose. At the end of experiments, the medium supernatant and blank medium were collected, and absorbance was measured. LNCaP-AI and LNCaP cells were harvested to detect PFKFB4 expression by Western blotting. Prostate tissue samples including PCa tissue, carcinoma-adjacent tissue and benign prostatic hyperplasia (BPH) tissue specimens were evaluated for PFKFB4 expression using immunohistochemistry.

Results

In 18 h supernatant samples, the glucose consumption and lactate secretion of LNCaP-AI cells were higher than those of LNCaP cells. The Western blot results indicated that PFKFB4 expression was increased in LNCaP-AI cells compared with LNCaP cells. Immunohistochemistry revealed that the expression of PFKFB4 in PCa tissue specimens was higher than that in BPH and adjacent tissue specimens. However, the differences in PCa tissue before and after ADT were not statistically significant.

Conclusion

PFKFB4 may be associated with enhanced glycolysis during the androgen-independent growth of PCa cells in vitro. PFKFB4 may be a marker of PCa progression. Our results provide a rationale for further clinical investigation of PCa treatment focused on controlling PFKFB4 expression.

Adaptive changes induced by noble-metal nanostructures in vitro and in vivo

The unique features of noble-metal nanostructures (NMNs) are leading to unprecedented expansion of research and exploration of their application in therapeutics, diagnostics and bioimaging fields. With the ever-growing applications of NMNs, both therapeutic and environmental NMNs are likely to be exposed to tissues and organs, requiring careful studies towards their biological effects in vitro and in vivo. Upon NMNs exposure, tissues and cells may undergo a series of adaptive changes both in morphology and function. At the cellular level, the accumulation of NMNs in various subcellular organelles including lysosomes, endoplasmic reticulum, Golgi apparatus, mitochondria, and nucleus may interfere with their functions, causing changes in a variety of cellular functions, such as digestion, protein synthesis and secretion, energy metabolism, mitochondrial respiration, and proliferation. In animals, retention of NMNs in metabolic-, respiratory-, immune-related, and other organs can trigger significant physiological and pathological changes to these organs and influence their functions. Exploring how NMNs interact with tissues and cells and the underlying mechanisms are of vital importance for their future applications. Here, we illustrate the characteristics of NMNs-induced adaptive changes both in vitro and in vivo. Potential strategies in the design of NMNs are also discussed to take advantage of beneficial adaptive changes and avoid unfavorable changes for the proper implementation of these nanoplatforms.

PTEN-deficient cells prefer glutamine for metabolic synthesis

PTEN loss-of-function mutations frequently occur in gliomas and lead to poor overall survival. PTEN deficiency induces metabolic reprogramming, which may provide therapeutic targets. PTEN is known to impact the Warburg effect and glutaminolysis. To uncover essential glutamine-related metabolic changes specific in PTEN-deficient cells and thus provide potential therapeutic targets, we performed capillary electrophoresis–mass spectrometry-based metabolomics analysis and metabolic flux analysis under different glutamine culture conditions and PTEN alteration status. Glu, Asn, Gly, Ala, and 1-methylnicotinamide were decreased in PTEN-deficient cells under normal culture conditions. Meanwhile, under Gln-deprived culture conditions, Glu, citrate, and UTP synthesis were reduced and acetyl carnitine was increased in PTEN-deficient cells. The reliance on Gln was increased for metabolic intermediates synthesis but decreased for energy production in PTEN-deficient cells. However, the reliance on Gln for UTP synthesis cannot be targeted due to anaplerotic synthesis of UTP from other sources. How to target these metabolic addictions needs further research.

Delineating cell behavior and metabolism of non-melanoma skin cancer in vitro

Non-melanoma skin cancers - basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) - are the most frequent forms of malignant neoplasm in humans worldwide. The etiology of these carcinomas is multifactorial. In addition to the harmful effect of UV light, altered cross-talk between neoplastic epithelial cells and the supporting dermal fibroblasts contributes to the regulation of tumor cell behavior, growth and survival. Metabolic cooperation between these cell types allows them to adapt and react to changes in their surrounding microenvironment by modifying their cellular bioenergetics and biosynthesis. We characterized the growth, behavior, and metabolic activity of human BCC cells, E-cadherin-competent SCC cells and E-cadherin-suppressed SCC cells in the presence or absence of dermal fibroblasts. In mono-cultures and co-cultures, BCC and SCC cells demonstrated distinct morphology, growth and organizational patterns. These tumor cells also exhibited unique patterns of consumption and secretion profiles of glucose, lactate, acetate, glutamine, glutamate, and pyruvate. In comparison to mono-cultures, growth of fibroblasts with either BCC cells or SCC cells enriched the cell growth environment, allowed for metabolic cooperation between these two cell types, and resulted in alterations in the metabolic profiles of the co-cultures. These alterations were affected by the cancer cell type, culture confluence and the composition of the growth medium. Characterizing the bioenergetics of BCC and SCC cells in the context of tumor-stromal interactions is not only important for further understanding of tumor pathogenesis, but also can illuminate potential new targets for novel, metabolic-based therapies for non-melanoma skin cancers.

Metabolic Reprogramming in Cancer Is Induced to Increase Proton Production

Considerable metabolic reprogramming has been observed in a conserved manner across multiple cancer types, but their true causes remain elusive. We present an analysis of around 50 such reprogrammed metabolisms (RM) including the Warburg effect, nucleotide de novo synthesis, and sialic acid biosynthesis in cancer. Analyses of the biochemical reactions conducted by these RMs, coupled with gene expression data of their catalyzing enzymes, in 7,011 tissues of 14 cancer types, revealed that all RMs produce more H⁺ than their original metabolisms. These data strongly support a model that these RMs are induced or selected to neutralize a persistent intracellular alkaline stress due to chronic inflammation and local iron overload. To sustain these RMs for survival, cells must find metabolic exits for the nonproton products of these RMs in a continuous manner, some of which pose major challenges, such as nucleotides and sialic acids, because they are electrically charged. This analysis strongly suggests that continuous cell division and other cancerous behaviors are ways for the affected cells to remove such products in a timely and sustained manner. As supporting evidence, this model can offer simple and natural explanations to a range of long-standing open questions in cancer research including the cause of the Warburg effect. SIGNIFICANCE: Inhibiting acidifying metabolic reprogramming could be a novel strategy for treating cancer.

FOXE1 represses cell proliferation and Warburg effect by inhibiting HK2 in colorectal cancer

BACKGROUND

Low expression of FOXE1, a member of Forkhead box (FOX) transcription factor family that plays vital roles in cancers, contributes to poor prognosis of colorectal cancer (CRC) patients. However, the underlying mechanism remains unclear.

MATERIALS AND METHODS

The effects of FOXE1 on the growth of colon cancer cells and the expression of glycolytic enzymes were investigated in vitro and in vivo. Molecular biological experiments were used to reveal the underlying mechanisms of altered aerobic glycolysis. CRC tissue specimens were used to determine the clinical association of ectopic metabolism caused by dysregulated FOXE1.

RESULTS

FOXE1 is highly expressed in normal colon tissues compared with cancer tissues and low expression of FOXE1 is significantly associated with poor prognosis of CRC patients. Silencing FOXE1 in CRC cell lines dramatically enhanced cell proliferation and colony formation and promoted glucose consumption and lactate production, while enforced expression of FOXE1 manifested the opposite effects. Mechanistically, FOXE1 bound directly to the promoter region of HK2 and negatively regulated its transcription. Furthermore, the expression of FOXE1 in CRC tissues was negatively correlated with that of HK2.

CONCLUSION

FOXE1 functions as a critical tumor suppressor in regulating tumor growth and glycolysis via suppressing HK2 in CRC.