Role of multifaceted regulators in cancer glucose metabolism and their clinical significance

An abnormal metabolism-related gene, ALG3, is a potential diagnostic and prognostic biomarker for lung adenocarcinoma

BACKGROUND

To explore the abnormal metabolism-related genes that affect the prognosis of patients with lung adenocarcinoma (LUAD), and analyze the relationship with immune infiltration and competing endogenous RNA (ceRNA) network.

METHODS

Transcriptome data of LUAD were downloaded from the Cancer Genome Atlas database. Abnormal metabolism-related differentially expressed genes in LUAD were screened by the R language. Cox analysis was used to construct LUAD prognostic risk model. Kaplan-Meier test, ROC curve and nomograms were used to evaluate the predictive ability of metabolic related gene prognostic model. CIBERSORT algorithm was used to analyze the relationship between risk score and immune infiltration. The starBase database constructed a regulatory network consistent with the ceRNA hypothesis. IHC experiments were performed to verify the differential expression of ALG3 in LUAD and paracancerous samples.

RESULTS

In this study, 42 abnormal metabolism-related differential genes were screened. After survival analysis, the final 5 metabolism-related genes were used as the construction of prognosis model, including ALG3, COL7A1, KL, MST1, and SLC52A1. In the model, the survival rate of LUAD patients in the high-risk subgroup was lower than that in the low-risk group. In addition, the risk score of the constructed LUAD prognostic model can be used as an independent prognostic factor for patients. According to the analysis of CIBERSORT algorithm, the risk score is related to the infiltration of multiple immune cells. The potential ceRNA network of model genes in LUAD was constructed through the starBase database. IHC experiments revealed that ALG3 expression was upregulated in LUAD.

CONCLUSION

The prognostic model of LUAD reveals the relationship between metabolism and prognosis of LUAD, and provides a novel perspective for diagnosis and research of LUAD.

Succinate-Directed Approaches for Warburg Effect-Targeted Cancer Management, an Alternative to Current Treatments?

Approximately a century ago, Otto Warburg discovered that cancer cells use a fermentative rather than oxidative metabolism even though the former is more inefficient in terms of energy production per molecule of glucose. Cancer cells increase the use of this fermentative metabolism even in the presence of oxygen, and this process is called aerobic glycolysis or the Warburg effect. This alternative metabolism is mainly characterized by higher glycolytic rates, which allow cancer cells to obtain higher amounts of total ATP, and the production of lactate, but there are also an activation of protumoral signaling pathways and the generation of molecules that favor cancer progression. One of these molecules is succinate, a Krebs cycle intermediate whose concentration is increased in cancer and which is considered an oncometabolite. Several protumoral actions have been associated to succinate and its role in several cancer types has been already described. Despite playing a major role in metabolism and cancer, so far, the potential of succinate as a target in cancer prevention and treatment has remained mostly unexplored, as most previous Warburg-directed anticancer strategies have focused on other intermediates. In this review, we aim to summarize succinate's protumoral functions and discuss the use of succinate expression regulators as a potential cancer therapy strategy.

Revisited Metabolic Control and Reprogramming Cancers by Means of the Warburg Effect in Tumor Cells

Aerobic glycolysis is an emerging hallmark of many human cancers, as cancer cells are defined as a “metabolically abnormal system”. Carbohydrates are metabolically reprogrammed by its metabolizing and catabolizing enzymes in such abnormal cancer cells. Normal cells acquire their energy from oxidative phosphorylation, while cancer cells acquire their energy from oxidative glycolysis, known as the “Warburg effect”. Energy–metabolic differences are easily found in the growth, invasion, immune escape and anti-tumor drug resistance of cancer cells. The glycolysis pathway is carried out in multiple enzymatic steps and yields two pyruvate molecules from one glucose (Glc) molecule by orchestral reaction of enzymes. Uncontrolled glycolysis or abnormally activated glycolysis is easily observed in the metabolism of cancer cells with enhanced levels of glycolytic proteins and enzymatic activities. In the “Warburg effect”, tumor cells utilize energy supplied from lactic acid-based fermentative glycolysis operated by glycolysis-specific enzymes of hexokinase (HK), keto-HK-A, Glc-6-phosphate isomerase, 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase, phosphofructokinase (PFK), phosphor-Glc isomerase (PGI), fructose-bisphosphate aldolase, phosphoglycerate (PG) kinase (PGK)1, triose phosphate isomerase, PG mutase (PGAM), glyceraldehyde-3-phosphate dehydrogenase, enolase, pyruvate kinase isozyme type M2 (PKM2), pyruvate dehydrogenase (PDH), PDH kinase and lactate dehydrogenase. They are related to glycolytic flux. The key enzymes involved in glycolysis are directly linked to oncogenesis and drug resistance. Among the metabolic enzymes, PKM2, PGK1, HK, keto-HK-A and nucleoside diphosphate kinase also have protein kinase activities. Because glycolysis-generated energy is not enough, the cancer cell-favored glycolysis to produce low ATP level seems to be non-efficient for cancer growth and self-protection. Thus, the Warburg effect is still an attractive phenomenon to understand the metabolic glycolysis favored in cancer. If the basic properties of the Warburg effect, including genetic mutations and signaling shifts are considered, anti-cancer therapeutic targets can be raised. Specific therapeutics targeting metabolic enzymes in aerobic glycolysis and hypoxic microenvironments have been developed to kill tumor cells. The present review deals with the tumor-specific Warburg effect with the revisited viewpoint of recent progress.

Metabolic Reprogramming of Innate Immune Cells as a Possible Source of New Therapeutic Approaches in Autoimmunity

Immune cells undergo different metabolic pathways or immunometabolisms to interact with various antigens. Immunometabolism links immunological and metabolic processes and is critical for innate and adaptive immunity. Although metabolic reprogramming is necessary for cell differentiation and proliferation, it may mediate the imbalance of immune homeostasis, leading to the pathogenesis and development of some diseases, such as autoimmune diseases. Here, we discuss the effects of metabolic changes in autoimmune diseases, exerted by the leading actors of innate immunity, and their role in autoimmunity pathogenesis, suggesting many immunotherapeutic approaches.

Therapeutic approach for digestive system cancers and potential implications of exercise under hypoxia condition: what little is known? a narrative review

BACKGROUND

Cancer, like other chronic pathologies, is associated with the presence of hypoxic regions due to the uncontrolled cell growth. Under this pathological hypoxic condition, various molecular signaling pathways are activated to ensure cell survival, such as those that govern angiogenesis, erythropoiesis, among others. These molecular processes are very similar to the physiological response caused by exposure to altitude (natural hypobaric systemic hypoxia), the use of artificial hypoxia devices (systemic normobaric simulated hypoxia) or the delivery of vascular occlusion to the extremities (also called local hypoxia by the blood flow restriction technique). "Tumor hypoxia" has gained further clinical importance due to its crucial role in both tumor progression and resistance to treatment. However, the ability to manipulate this pathway through physical exercise and systemic hypoxia-mediated signaling pathways could offer an important range of therapeutic opportunities that should be further investigated.

METHODS

This review is focused on the potential implications of systemic hypoxia combined with exercise in digestive system neoplasms prognosis. Articles included in the review were retrieved by searching among the three main scientific databases: PubMed, Scopus, and Embase.

FINDINGS

The findings of this review suggest that exercise performed under systemic hypoxic conditions could have a positive impact in prognosis and quality of life of the population with digestive system cancers.

CONCLUSIONS

Further studies are needed to consider this paradigm as a new potential intervention in digestive oncological population.

The pleiotropic peroxisome proliferator activated receptors: Regulation and therapeutics

The Peroxisome proliferator-activated receptors (PPARs) are key regulators of metabolic events in our body. Owing to their implication in maintenance of homeostasis, both PPAR agonists and antagonists assume therapeutic significance. Understanding the molecular mechanisms of each of the PPAR isotypes in the healthy body and during disease is crucial to exploiting their full therapeutic potential. This article is an attempt to present a rational analysis of the multifaceted therapeutic effects and underlying mechanisms of isotype-specific PPAR agonists, dual PPAR agonists, pan PPAR agonists as well as PPAR antagonists. A holistic understanding of the mechanistic dimensions of these key metabolic regulators will guide future efforts to identify novel molecules in the realm of metabolic, inflammatory and immunotherapeutic diseases.

Breast cancer fibroblasts and cross-talk

The breast tumor microenvironment is one of the crucial elements supporting breast cancer tumor progression and metastasis. The fibroblasts are the chief cellular component of the stromal microenvironment and are pathologically activated and differentiated into breast cancer-associated fibroblasts (CAFs). The catabolic phenotype of breast CAFs arises due to metabolic reprogramming of these fibroblasts under pseudo-hypoxic conditions. The metabolic intermediates and ATP produced by the breast CAFs are exploited by the neighboring cancer cells for energy generation. The growth factors, cytokines, and chemokines secreted by the CAFs help fuel tumor growth, invasion, and dissemination. Moreover, the interplay between breast CAFs and cancer cells, mediated by the growth factors, ROS, metabolic intermediates, exosomes, and catabolite transporters, aids in building a favorable microenvironment that promotes cancer cell proliferation, tumor progression, and metastasis. Therefore, identifying effective means to target the reprogrammed metabolism of the breast CAFs and the cross-communication between CAFs and cancer cells serve as promising strategies to develop anti-cancer therapeutics. Henceforth, the scope of the present review ranges from discussing the underlying characteristics of breast CAFs, mechanisms of metabolic reprogramming in breast CAFs, and the nature of interactions between breast CAFs and cancer cells to studying the intricacies of reprogrammed metabolism targeted cancer therapy.

Lipid metabolism in cancer: A systematic review

Preclinical studies and clinical trials have emphasized the decisive role of lipid metabolism in tumor proliferation and metastasis. This systematic review aimed to explore the existing literature to evaluate the role and significance of the genes and pathways most commonly involved in the regulation of lipid metabolism in cancer. The literature search was performed as per Preferred Reporting Items for Systematic Reviews and Meta-analyses. Approximately 2396 research articles were initially selected, of which 215 were identified as potentially relevant for abstract review. Upon further scrutiny, 62 of the 215 studies were reviews, seminars, or presentations, and 44 were original study articles and were thus included in the systematic review. The predominant gene involved in lipid metabolism in cancer was stearoyl-coenzyme A desaturase 1 (SCD1), followed by fatty acid synthase (FASN). The pathway most commonly involved in lipid metabolism in cancer was the phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) signaling pathway, followed by the mitogen activated protein kinase (MAPK) pathway. SCD1 and FASN play significant roles in the initiation and progression of cancer and represent attractive targets for potentially effective anti-cancer treatment strategies. The regulation of cancer metabolism by the Akt kinases will be an interesting topic of future study.

HIF1 may promote glycolysis in psoriasis vulgaris via upregulation of CD147 and GLUT1

OBJECTIVES

To analyze the expressions and distributions of hypoxia-inducible factor-1α (HIF-1α), CD147, and glucose transporter 1 (GLUT1) in epidermis from psoriasis vulgaris and normal people, and to explore the associations among these proteins and their roles in hypoxic HaCaT cell line.

METHODS

The expression levels of HIF-1α, CD147, and GLUT1 were determined by immunohistochemistry staining in skin biopsies from 48 psoriasis vularis patients and 33 healthy subjects. Cobalt chloride (CoCl2) was added into the culture media of HaCaT cells to mimic hypoxia while RNA interference and transfection technologies were used to explore the association among these proteins by quantitative real-time polymerase chain reaction and Western blotting. Glycolytic capacity was detected by ATP and lactate measurements.

RESULTS

HIF-1α, CD147, and GLUT1 were highly expressed and the glycolytic capacity was increased in lesions of psoriasis vulgaris; HIF-1α upregulated the expression of CD147 and GLUT1, increased the lactate production and decreased the ATP level in CoCl2-treated HaCaT cells, while CD147 and GLUT1 directly or indirectly bound to each other.

CONCLUSIONS

Glycolytic capacity increases in the injured keratinocytes of psoriasis vulgaris, suggesting that HIF-1α, CD147, and GLUT1 are associated with glycolysis, which can be considered as the promising targets for psoriasis therapy.

KLF4 Regulates Metabolic Homeostasis in Response to Stress

Cancerous cells are detrimental to the human body and can be incredibly resilient against treatments because of the complexities of molecular carcinogenic pathways. In particular, cancer cells are able to sustain increased growth under metabolic stress due to phenomena like the Warburg effect. Krüppel-like factor 4 (KLF4), a context-dependent transcription factor that can act as both a tumor suppressor and an oncogene, is involved in many molecular pathways that respond to low glucose and increased reactive oxygen species (ROS), raising the question of its role in metabolic stress as a result of increased proliferation of tumor cells. In this study, metabolic assays were performed, showing enhanced efficiency of energy production in cells expressing KLF4. Western blotting showed that KLF4 increases the expression of essential glycolytic proteins. Furthermore, we used immunostaining to show that KLF4 increases the localization of glucose transporter 1 (GLUT1) to the cellular membrane. 2',7'-Dichlorodihydrofluorescein diacetate (H2DCF-DA) was used to analyze the production of ROS, and we found that KLF4 reduces stress-induced ROS within cells. Finally, we demonstrated increased autophagic death in KLF4-expressing cells in response to glucose starvation. Collectively, these results relate KLF4 to non-Warburg metabolic behaviors that support its role as a tumor suppressor and could make KLF4 a target for new cancer treatments.

In silico identification of potential inhibitor for TP53-induced glycolysis and apoptosis regulator in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is the six most common cancer globally and most common cancer in men in India. The metabolic regulation is highly altered and is considered as a hall mark of HNSCC. TP53-induced glycolysis and apoptosis regulator (TIGAR) plays very important role in the development and progression of HNSCC. The aim of our study is to identify a novel FDA approved anticancer inhibitor against mutated TP53-induced glycolysis and apoptosis regulator (TIGAR) through drug repurposing approach. A library of 105 FDA approved anticancer compounds were screened using molecular docking approach against TIGAR (PDB: 3DCY) both Wild-Type (WT) and mutated (Mut). Specific mutations in TIGAR were identified using cBioPortal, a cancer genomics database and mutated structure was modelled using SWISS-MODEL. Out of 510 sequenced cases/patients samples, 17(3%) patients showed alteration in TIGAR [TIGAR^WT and TIGAR^{Mut (R88W)}]. The virtual drug screening showed 45 drugs out of 105 high binding affinity with TIGAR, Trabectedin showed highest binding affinity with both TIGAR^WT (- 13.3 kcal/mol) as well as TIGAR^{Mut (R88W)} (- 13.8 kcal/mol). The molecular docking studies were validated using molecular dynamics simulation (MD Simulation) of protein-ligand complex of TIGAR and Trabectedin for 100 ns. The MD Simulation of Trabectedin complex showed more stable with TIGAR^{Mut (R88W)} compared to TIGAR^WT. Moreover, the string analysis revealed that metabolic-related genes, HK2, PFKFB1, PFKM, PFKP, PFKL, FBP1 are closely associated with TIGAR in HNSCC. Our findings suggest that Trabectedin can be proposed as an inhibitor for [TIGAR^{Mut (R88W)}] which can be used to target metabolic signalings in HNSCC. However, further investigation and in vitro and in vivo validation our findings required to understand the molecular mechanisms of regulation of Trabectedin in HNSCC.

MiR-22 modulates brown adipocyte thermogenesis by synergistically activating the glycolytic and mTORC1 signaling pathways

Background: Brown adipose tissue (BAT) dissipates chemical energy as heat and has the potential to be a protective strategy to prevent obesity. microRNAs (miRNAs) are emerging as important posttranscriptional factors affecting the thermogenic function of BAT. However, the regulatory mechanism underlying miRNA-mediated energy metabolism in BAT is not fully understood. Here, we explored the roles of miR-22 in BAT thermogenesis and energy metabolism.

Methods: Using global and conditional knockout mice as in vivo models and primary brown adipocytes as an in vitro system, we investigated the function of miR-22 in BAT thermogenesis in vivo and in vitro.

Results: miR-22 expression was upregulated in BAT in response to cold exposure and during brown preadipocyte differentiation. Both global and conditional knockout mice displayed BAT whitening, impaired cold tolerance, and decreased BAT thermogenesis. Moreover, we found that miR-22 deficiency impaired BAT glycolytic capacity, which is critical for thermogenesis. The mechanistic results revealed that miR-22 activated the mTORC1 signaling pathway by directly suppressing Tsc1 and concomitantly directly suppressing Hif1an, an inhibitor of Hif1α, which promotes glycolysis and maintains thermogenesis.

Conclusions: Our findings identify miR-22 as a critical regulator in the control of thermogenesis in BAT and as a potential therapeutic target for human metabolic disorders.

The P53/microRNA network: A potential tumor suppressor with a role in anticancer therapy

MicroRNAs (miRNAs) are endogenous and small non-coding RNAs that have been identified as mediators of tumor suppression as well as stress responses mediated by p53 suppressors. MiRNAs may act as tumor suppressors under certain conditions. MiRNAs regulated by p53 may control the expression of processes such as cell cycle progression, cell survival, and angiogenesis. P53 activity and expression are also controlled by miRNA; consequently alterations in the p53-miRNA network may be essential for tumor initiation and progression. Future studies on the p53-miRNA network presumably would find it helpful in diagnostic and therapeutic approaches or as tools for various cancers.

HBXIP Regulates Gastric Cancer Glucose Metabolism and Malignancy Through PI3K/AKT and p53 Signaling

Introduction

Hepatitis B X-interacting protein (HBXIP) overexpression is related to the progression of multiple cancers. However, its role in gastric cancer (GC) remains unclear.

Materials and Methods

HBXIP expression was determined in human GC specimens and cell lines by quantitative polymerase chain reaction (qRT-PCR) and Western blot. The effects of HBXIP depletion or ectopic expression on GC proliferation were evaluated in vitro using the cell counting kit-8 (CCK-8), 5-ethynyl-2ʹ-deoxyuridine (EdU) incorporation, colony formation, and cell cycle assays. The in vivo effects were investigated using a mouse xenograft model. Apoptosis was evaluated by flow cytometry (in vitro) and immunohistochemistry (IHC; in vivo). Cell migration and invasion were evaluated in vitro using wound healing, transwell migration, and matrigel invasion assays; and in vivo by quantifying distant metastases from injection of GC cells in the lateral tail vein.

Results

Herein, we reported that HBXIP expression was higher in GC than in normal tissues, and this high expression indicated a poorer prognosis. Gain- and loss-of-function assays showed that HBXIP promoted GC proliferation, migration, and invasion, and inhibited apoptosis. High-performance liquid chromatography (HPLC) quantification of glycolytic metabolites revealed that HBXIP promoted glucose metabolic reprogramming. Investigation of the PI3K/AKT and p53 pathways highlighted their role in this HBXIP-mediated metabolic reprogramming.

Conclusion

Our results indicate that the up-regulation of HBXIP leads to GC progression by positively regulating glucose metabolism. Therefore, HBXIP is a potential target for the treatment of GC.

Immunomodulatory Protein from Nectria haematococca Induces Apoptosis in Lung Cancer Cells via the P53 Pathway

Our previous research has shown that a fungal immunomodulatory protein from Nectria haematococca (FIP-nha) possesses a wide spectrum of anti-tumor activities, and FIP-nha induced A549 apoptosis by negatively regulating the PI3K/Akt signaling pathway based on comparative quantitative proteomics. This study further confirmed that the anti-lung cancer activity of FIP-nha was significantly stronger than that of the reported LZ-8 and FIP-fve. Subsequently, ¹H NMR-based metabolomics was applied to comprehensively investigate the underlying mechanism, and a clear separation of FIP-nha-treated and untreated groups was achieved using pattern recognition analysis. Four potential pathways associated with the anti-tumor effect of FIP-nha on A549 cells were identified, and these were mainly involved in glycolysis, taurine and hypotaurine metabolism, fructose and mannose metabolism, and glycerolipid metabolism. Metabolic pathway analysis demonstrated that FIP-nha could induce A549 cell apoptosis partly by regulating the p53 inhibition pathway, which then disrupted the Warburg effect, as well as through other metabolic pathways. Using RT-PCR analysis, FIP-nha-induced apoptosis was confirmed to occur through upregulation of p53 expression. This work highlights the possible use of FIP-nha as a therapeutic adjuvant for lung cancer treatment.

Effects of hypoxia‑inducible factor‑1α on the proliferation and apoptosis of human synovial mesenchymal stem cells

Hypoxia is a constant feature of the synovial microenvironment. How synovial mesenchymal stem cells (SMSCs) proliferate and differentiate in a hypoxic environment over a long period of time has aroused the interest of researchers. The aim of the present study was to explore the effects of hypoxia‑inducible factor‑1α (HIF‑1α) on the proliferation and apoptosis of human SMSCs. SMSCs were harvested and cultured under different concentration of oxygen, normoxia (21% O2), hypoxia (5% O2) and severe hypoxia (0.5% O2) to determine its effect on the expression of HIF‑1α. Then, the cells were collected and cell proliferation and apoptosis were detected at severe hypoxia (0.5% O2) and hypoxia (5% O2) conditions following HIF‑1α siRNA transfection. There were no significant changes in cellular proliferation or apoptosis when cultured in normoxia (21% O2), hypoxia (5% O2) or severe hypoxia (0.5% O2). However, the mRNA and protein expression of HIF‑1α were markedly upregulated in the hypoxic conditions. Further experiments suggested that the proliferation of SMSCs was obviously suppressed and apoptosis was markedly increased under severe hypoxic (0.5%) and hypoxic (5% O2) conditions following HIF‑1α siRNA transfection. In conclusion, HIF‑1α effectively improved the tolerance of SMSCs to hypoxia, which may promote cellular proliferation and prevent the apoptosis of SMSCs under hypoxic conditions.

PKM2 enhances cancer invasion via ETS-1-dependent induction of matrix metalloproteinase in oral squamous cell carcinoma cells

OBJECTIVES

This study aimed at investigating the molecular mechanism underlying PKM2-mediated cancer invasion.

MATERIALS & METHODS

To optimize the investigation of PKM2-specific effects, we used two immortalized oral cell lines. The two cell lines drastically differed in PKM2 expression level, particularly in the level of nuclear PKM2, and subsequently in glucose metabolism and tumorigenicity.

RESULTS

Knockdown of PKM2 reduced not only the glucose metabolism but also the invasive activity by curtailing the expressions of matrix metalloproteinases (MMP): PKM2 could modulate MMP-9 expression by regulating ETS-1 inside the nucleus. These results were further confirmed in an oral squamous cell carcinoma (OSCC) cell line. In correspondence with in vitro findings, clinicopathological data from OSCC patients indicated strong association between PKM2 expression and poor survival rate. Additionally, upon analysis of public database, significant positive correlation was found between PKM2 and ETS-1 in OSCC.

CONCLUSION

Collectively, this study unveiled the molecular mechanism underlying PKM2-mediated cancer invasion, thereby providing novel targets for therapeutics development against invasive OSCC.

Metabolic Intermediates in Tumorigenesis and Progression

Traditional antitumor drugs inhibit the proliferation and metastasis of tumour cells by restraining the replication and expression of DNA. These drugs are usually highly cytotoxic. They kill tumour cells while also cause damage to normal cells at the same time, especially the hematopoietic cells that divide vigorously. Patients are exposed to other serious situations such as a severe infection caused by a decrease in the number of white blood cells. Energy metabolism is an essential process for the survival of all cells, but differs greatly between normal cells and tumour cells in metabolic pathways and metabolic intermediates. Whether this difference could be used as new therapeutic target while reducing damage to normal tissues is the topic of this paper. In this paper, we introduce five major metabolic intermediates in detail, including acetyl-CoA, SAM, FAD, NAD⁺ and THF. Their contents and functions in tumour cells and normal cells are significantly different. And the possible regulatory mechanisms that lead to these differences are proposed carefully. It is hoped that the key enzymes in these regulatory pathways could be used as new targets for tumour therapy.

Met is involved in TIGAR-regulated metastasis of non-small-cell lung cancer

TIGAR is a p53 target gene that is known to protect cells from ROS-induced apoptosis by promoting the pentose phosphate pathway. The role of TIGAR in tumor cell invasion and metastasis remains elusive. Here we found that downregulation of TIGAR reduced the invasion and metastasis of NSCLC cells in vitro and in vivo. Immunohistochemical analysis of 72 NSCLC patients showed that TIGAR and Met protein expression was positively correlated with late stages of lung cancer. Besides, patients with high co-expression of TIGAR and Met presented a significantly worse survival. In addition, we found that Met signaling pathway is involved in TIGAR-induced invasion and metastasis. Our study indicates that TIGAR/Met pathway may be a novel target for NSCLC therapy. It is necessary to evaluate the expression of TIGAR before Met inhibitors are used for NSCLC treatment.

The fructose-2,6-bisphosphatase TIGAR suppresses NF-κB signaling by directly inhibiting the linear ubiquitin assembly complex LUBAC

The systems integration of whole-body metabolism and immune signaling are central homeostatic mechanisms necessary for maintenance of normal physiology, and dysregulation of these processes leads to a variety of chronic disorders. However, the intracellular mechanisms responsible for cell-autonomous cross-talk between the inflammatory signaling pathways and metabolic flux have remained enigmatic. In this study, we discovered that the fructose-2,6-bisphosphatase TIGAR (Tp53-induced glycolysis and apoptosis regulator) critically regulates NF-κB activation. We found that TIGAR potently inhibits NF-κB-dependent gene expression by suppressing the upstream activation of IKKβ phosphorylation and kinase activation. This inhibition occurred through a direct binding competition between NEMO and TIGAR for association with the linear ubiquitination assembly complex (LUBAC). This competition prevented linear ubiquitination of NEMO, which is required for activation of IKKβ and other downstream targets. Furthermore, a TIGAR phosphatase activity-deficient mutant was equally effective as WT TIGAR in inhibiting NEMO linear ubiquitination, IKKβ phosphorylation/activation, and NF-κB signaling, indicating that TIGAR's effect on NF-κB signaling is due to its interaction with LUBAC. Physiologically, TIGAR knockout mice displayed enhanced adipose tissue NF-κB signaling, whereas adipocyte-specific overexpression of TIGAR suppressed adipose tissue NF-κB signaling. Together, these results demonstrate that TIGAR has a nonenzymatic molecular function that modulates the NF-κB signaling pathway by directly inhibiting the E3 ligase activity of LUBAC.

PGK1 and GRP78 overexpression correlates with clinical significance and poor prognosis in Chinese endometrial cancer patients

The aim of this study was to measure the expression patterns of PGK1 and GRP78 in normal endometrial tissues and endometrial carcinoma, and associations between their combined effects and the pathological features of endometrial carcinoma. We used 30 normal endometrial tissue samples and 130 endometrial carcinoma samples, and separately evaluated PGK1 and GRP78 protein expression by immunohistochemistry. Scores ranging from 0 to 9 were obtained by multiplying the percentage of positive cells by the staining intensity (0–3). Immunohistochemical analysis revealed increased PGK1 and GRP78 expression in the cytoplasm of endometrial carcinoma cells compared with that in normal endometrial tissues. High PGK1 expression positively correlated with the FIGO stage (P < 0.001), histological grade (P = 0.002), and lymph node status (P < 0.001). High GRP78 expression positively correlated with the pathological type (P = 0.0125), FIGO stage (P < 0.001), and lymph node status (P < 0.001). In addition, PGK1 overexpression was positively correlated with GRP78 overexpression in endometrial carcinoma patients (P < 0.001), and the concurrent expression of both oncogenes in endometrial carcinoma patients correlated significantly with the lymph node status (P < 0.001) and FIGO stage (P < 0.001). Patients with high PGK1 and GRP78 expression levels had poorer overall survival rates than those with low expression levels of both proteins (P < 0.001). Our results suggested that the co-occurrence of PGK1 and GRP78 expression is potentially an unfavorable factor for endometrial carcinoma progression.

A Nutritional Perspective of Ketogenic Diet in Cancer: A Narrative Review

The predominant use of glucose anaerobically by cancer cells (Warburg effect) may be the most important characteristic the majority of these cells have in common and, therefore, a potential metabolic pathway to be targeted during cancer treatment. Because this effect relates to fuel oxidation, dietary manipulation has been hypothesized as an important strategy during cancer treatment. As such, the concept of a ketogenic diet (KD) in cancer emerged as a metabolic therapy (ie, targeting cancer cell metabolism) rather than a dietary approach. The therapeutic mechanisms of action of this high-fat, moderate-to-low protein, and very-low-carbohydrate diet may potentially influence cancer treatment and prognosis. Considering the lack of a dietetics-focused narrative review on this topic, we compiled the evidence related to the use of this diet in humans with diverse cancer types and stages, also focusing on the nutrition and health perspective. The use of KD in cancer shows potentially promising, but inconsistent, results. The limited number of studies and differences in study design and characteristics contribute to overall poor quality evidence, limiting the ability to draw evidence-based conclusions. However, the potential positive influences a KD may have on cancer treatment justify the need for well-designed clinical trials to better elucidate the mechanisms by which this dietary approach affects nutritional status, cancer prognosis, and overall health. The role of registered dietitian nutritionists is demonstrated to be crucial in planning and implementing KD protocols in oncology research settings, while also ensuring patients' adherence and optimal nutritional status.

Deep-proteome mapping of WM-266-4 human metastatic melanoma cells: From oncogenic addiction to druggable targets

Cutaneous melanoma is a malignant tumor of skin melanocytes that are pigment-producing cells located in the basal layer (stratum basale) of epidermis. Accumulation of genetic mutations within their oncogenes or tumor-suppressor genes compels melanocytes to aberrant proliferation and spread to distant organs of the body, thereby resulting in severe and/or lethal malignancy. Metastatic melanoma's heavy mutational load, molecular heterogeneity and resistance to therapy necessitate the development of novel biomarkers and drug-based protocols that target key proteins involved in perpetuation of the disease. To this direction, we have herein employed a nano liquid chromatography-tandem mass spectrometry (nLC-MS/MS) proteomics technology to profile the deep-proteome landscape of WM-266-4 human metastatic melanoma cells. Our advanced melanoma-specific catalogue proved to contain 6,681 unique proteins, which likely constitute the hitherto largest single cell-line-derived proteomic collection of the disease. Through engagement of UNIPROT, DAVID, KEGG, PANTHER, INTACT, CYTOSCAPE, dbEMT and GAD bioinformatics resources, WM-266-4 melanoma proteins were categorized according to their sub-cellular compartmentalization, function and tumorigenicity, and successfully reassembled in molecular networks and interactomes. The obtained data dictate the presence of plastically inter-converted sub-populations of non-cancer and cancer stem cells, and also indicate the oncoproteomic resemblance of melanoma to glioma and lung cancer. Intriguingly, WM-266-4 cells seem to be subjected to both epithelial-to-mesenchymal (EMT) and mesenchymal-to-epithelial (MET) programs, with 1433G and ADT3 proteins being identified in the EMT/MET molecular interface. Oncogenic addiction of WM-266-4 cells to autocrine/paracrine signaling of IL17-, DLL3-, FGF(2/13)- and OSTP-dependent sub-routines suggests their critical contribution to the metastatic melanoma chemotherapeutic refractoriness. Interestingly, the 1433G family member that is shared between the BRAF- and EMT/MET-specific interactomes likely emerges as a novel and promising druggable target for the malignancy. Derailed proliferation and metastatic capacity of WM-266-4 cells could also derive from their metabolic addiction to pathways associated with glutamate/ammonia, propanoate and sulfur homeostasis, whose successful targeting may prove beneficial for advanced melanoma-affected patients.

WSB1: from homeostasis to hypoxia

The wsb1 gene has been identified to be important in developmental biology and cancer. A complex transcriptional regulation of wsb1 yields at least three functional transcripts. The major expressed isoform, WSB1 protein, is a substrate recognition protein within an E3 ubiquitin ligase, with the capability to bind diverse targets and mediate ubiquitinylation and proteolytic degradation. Recent data suggests a new role for WSB1 as a component of a neuroprotective pathway which results in modification and aggregation of neurotoxic proteins such as LRRK2 in Parkinson’s Disease, via an unusual mode of protein ubiquitinylation.

WSB1 is also involved in thyroid hormone homeostasis, immune regulation and cellular metabolism, particularly glucose metabolism and hypoxia. In hypoxia, wsb1 is a HIF-1 target, and is a regulator of the degradation of diverse proteins associated with the cellular response to hypoxia, including HIPK2, RhoGDI2 and VHL. Major roles are to both protect HIF-1 function through degradation of VHL, and decrease apoptosis through degradation of HIPK2. These activities suggest a role for wsb1 in cancer cell proliferation and metastasis. As well, recent work has identified a role for WSB1 in glucose metabolism, and perhaps in mediating the Warburg effect in cancer cells by maintaining the function of HIF1. Furthermore, studies of cancer specimens have identified dysregulation of wsb1 associated with several types of cancer, suggesting a biologically relevant role in cancer development and/or progression.

Recent development of an inducible expression system for wsb1 could aid in the further understanding of the varied functions of this protein in the cell, and roles as a potential oncogene and neuroprotective protein.

Cancer: An Oxidative Crosstalk between Solid Tumor Cells and Cancer Associated Fibroblasts

Redox balance is associated with the regulation of several cell signalling pathways and functions. In fact, under physiological conditions, cells maintain a balance between oxidant and antioxidant systems, and reactive oxygen species (ROS) can act as second messengers to regulate cell proliferation, cell death, and other physiological processes. Cancer tissues usually contain higher levels of ROS than normal tissues, and this ROS overproduction is associated with tumor development. Neoplastic tissues are very heterogeneous systems, composed of tumor cells and microenvironment that has a critical role in tumor progression. Cancer associated fibroblasts (CAFs) represent the main cell type of tumor microenvironment, and they contribute to tumor growth by undergoing an irreversible activation process. It is known that ROS can be transferred from cancer cells to fibroblasts. In particular, ROS affect the behaviour of CAFs by promoting the conversion of fibroblasts to myofibroblasts that support tumor progression and dissemination. Furthermore, the wrecking of redox homeostasis in cancer cells and tumor microenvironment induces a metabolic reprogramming in tumor cells and cancer associated fibroblasts, giving advantage to cancer growth. This review describes the role of ROS in tumor growth, by focusing on CAFs activation and metabolic interactions between cancer cells and stromal fibroblasts.