MYC-induced cancer cell energy metabolism and therapeutic opportunities

CK1δ and CK1ε Signaling Sustains Mitochondrial Metabolism and Cell Survival in Multiple Myeloma

Multiple myeloma remains an incurable malignancy due to acquisition of intrinsic programs that drive therapy resistance. Here we report that casein kinase-1δ (CK1δ) and CK1ε are therapeutic targets in multiple myeloma that are necessary to sustain mitochondrial metabolism. Specifically, the dual CK1δ/CK1ε inhibitor SR-3029 had potent in vivo and ex vivo anti-multiple myeloma activity, including against primary multiple myeloma patient specimens. RNA sequencing (RNA-seq) and metabolic analyses revealed inhibiting CK1δ/CK1ε disables multiple myeloma metabolism by suppressing genes involved in oxidative phosphorylation (OxPhos), reducing citric acid cycle intermediates, and suppressing complexes I and IV of the electron transport chain. Finally, sensitivity of multiple myeloma patient specimens to SR-3029 correlated with elevated expression of mitochondrial genes, and RNA-seq from 687 multiple myeloma patient samples revealed that increased CSNK1D, CSNK1E, and OxPhos genes correlate with disease progression and inferior outcomes. Thus, increases in mitochondrial metabolism are a hallmark of multiple myeloma progression that can be disabled by targeting CK1δ/CK1ε.

SIGNIFICANCE

CK1δ and CK1ε are attractive therapeutic targets in multiple myeloma whose expression increases with disease progression and connote poor outcomes, and that are necessary to sustain expression of genes directing OxPhos.

Research progress on the mechanism of glycolysis in ovarian cancer

Glycolysis is the preferred energy metabolism pathway in cancer cells even when the oxygen content is sufficient. Through glycolysis, cancer cells convert glucose into pyruvic acid and then lactate to rapidly produce energy and promote cancer progression. Changes in glycolysis activity play a crucial role in the biosynthesis and energy requirements of cancer cells needed to maintain growth and metastasis. This review focuses on ovarian cancer and the significance of key rate-limiting enzymes (hexokinase, phosphofructokinase, and pyruvate kinase, related signaling pathways (PI3K-AKT, Wnt, MAPK, AMPK), transcription regulators (HIF-1a), and non-coding RNA in the glycolytic pathway. Understanding the relationship between glycolysis and these different mechanisms may provide new opportunities for the future treatment of ovarian cancer.

Metabolic reprogramming and its clinical implication for liver cancer

Cancer cells often encounter hypoxic and hypo-nutrient conditions, which force them to make adaptive changes to meet their high demands for energy and various biomaterials for biomass synthesis. As a result, enhanced catabolism (breakdown of macromolecules for energy production) and anabolism (macromolecule synthesis from bio-precursors) are induced in cancer. This phenomenon is called "metabolic reprogramming," a cancer hallmark contributing to cancer development, metastasis, and drug resistance. HCC and cholangiocarcinoma (CCA) are 2 different liver cancers with high intertumoral heterogeneity in terms of etiologies, mutational landscapes, transcriptomes, and histological representations. In agreement, metabolism in HCC or CCA is remarkably heterogeneous, although changes in the glycolytic pathways and an increase in the generation of lactate (the Warburg effect) have been frequently detected in those tumors. For example, HCC tumors with activated β-catenin are addicted to fatty acid catabolism, whereas HCC tumors derived from fatty liver avoid using fatty acids. In this review, we describe common metabolic alterations in HCC and CCA as well as metabolic features unique for their subsets. We discuss metabolism of NAFLD as well, because NAFLD will likely become a leading etiology of liver cancer in the coming years due to the obesity epidemic in the Western world. Furthermore, we outline the clinical implication of liver cancer metabolism and highlight the computation and systems biology approaches, such as genome-wide metabolic models, as a valuable tool allowing us to identify therapeutic targets and develop personalized treatments for liver cancer patients.

A Nucleotide Metabolism-Related Gene Signature for Risk Stratification and Prognosis Prediction in Hepatocellular Carcinoma Based on an Integrated Transcriptomics and Metabolomics Approach

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related mortality worldwide. The in-depth study of genes and metabolites related to nucleotide metabolism will provide new ideas for predicting the prognosis of HCC patients. This study integrated the transcriptome data of different cancer types to explore the characteristics and significance of nucleotide metabolism-related genes (NMGRs) in different cancer types. Then, we constructed a new HCC classifier and prognosis model based on HCC samples from TCGA and GEO, and detected the gene expression level in the model through molecular biology experiments. Finally, nucleotide metabolism-related products in serum of HCC patients were examined using untargeted metabolomics. A total of 97 NMRGs were obtained based on bioinformatics techniques. In addition, a clinical model that could accurately predict the prognostic outcome of HCC was constructed, which contained 11 NMRGs. The results of PCR experiments showed that the expression levels of these genes were basically consistent with the predicted trends. Meanwhile, the results of untargeted metabolomics also proved that there was a significant nucleotide metabolism disorder in the development of HCC. Our results provide a promising insight into nucleotide metabolism in HCC, as well as a tailored prognostic and chemotherapy sensitivity prediction tool for patients.

Clinical Warburg effect in lymphoma patients admitted to intensive care unit

BACKGROUND

The Warburg effect, characterized by elevated lactate levels without tissue hypoxia or shock, has been described in patients with aggressive lymphoproliferative malignancies. However, the clinical characteristics and long-term outcomes in this population remain poorly understood.

METHODS

We retrospectively analyzed 135 patients with aggressive lymphoproliferative malignancies admitted to the ICU between January 2017 and December 2022. Patients were classified into three groups: Clinical Warburg Effect (CWE), No Warburg with High Lactate level (NW-HL), and No Warburg with Normal Lactate level (NW-NL). Clinical characteristics and outcomes were compared between the groups and factors associated with 1-year mortality and CWE were identified using multivariable analyses.

RESULTS

Of the 135 patients, 46 (34%) had a CWE. This group had a higher proportion of Burkitt and T cell lymphomas, greater tumor burden, and more frequent bone and cerebral involvement than the other groups. At 1 year, 72 patients (53%) died, with significantly higher mortality in the CWE and NW-HL groups (70% each) than in the NW-NL group (38%). Factors independently associated with 1-year mortality were age [HR = 1.02 CI 95% (1.00-1.04)], total SOFA score at admission [HR = 1.19 CI 95% (1.12-1.25)], and CWE [HR = 3.87 CI 95% (2.13-7.02)]. The main factors associated with the CWE were tumor lysis syndrome [OR = 2.84 CI 95% (1.14-7.42)], bone involvement of the underlying malignancy [OR = 3.58 CI 95% (1.02-12.91)], the total SOFA score at admission [OR = 0.81 CI 95% (0.69-0.91)] and hypoglycemia at admission [OR = 14.90 CI 95% (5.42-47.18)].

CONCLUSION

CWE is associated with a higher tumor burden and increased 1-year mortality compared to patients without this condition. Our findings underscore the importance of recognizing patients with CWE as a high-risk cohort, as their outcomes closely resemble those of individuals with lymphoma and shock, despite not requiring advanced organ support. Clinicians should recognize the urgency of managing these patients and consider early intervention to improve their prognosis.

Formyl-peptide receptor 2 signalling triggers aerobic metabolism of glucose through Nox2-dependent modulation of pyruvate dehydrogenase activity

The human formyl-peptide receptor 2 (FPR2) is activated by an array of ligands. By phospho-proteomic analysis we proved that FPR2 stimulation induces redox-regulated phosphorylation of many proteins involved in cellular metabolic processes. In this study, we investigated metabolic pathways activated in FPR2-stimulated CaLu-6 cells. The results showed an increased concentration of metabolites involved in glucose metabolism, and an enhanced uptake of glucose mediated by GLUT4, the insulin-regulated member of GLUT family. Accordingly, we observed that FPR2 transactivated IGF-IRβ/IRβ through a molecular mechanism that requires Nox2 activity. Since cancer cells support their metabolism via glycolysis, we analysed glucose oxidation and proved that FPR2 signalling promoted kinase activity of the bifunctional enzyme PFKFB2 through FGFR1/FRS2- and Akt-dependent phosphorylation. Furthermore, FPR2 stimulation induced IGF-IRβ/IRβ-, PI3K/Akt- and Nox-dependent inhibition of pyruvate dehydrogenase activity, thus preventing the entry of pyruvate in the tricarboxylic acid cycle. Consequently, we observed an enhanced FGFR-dependent lactate dehydrogenase (LDH) activity and lactate production in FPR2-stimulated cells. As LDH expression is transcriptionally regulated by c-Myc and HIF-1, we demonstrated that FPR2 signalling promoted c-Myc phosphorylation and Nox-dependent HIF-1α stabilization. These results strongly indicate that FPR2-dependent signalling can be explored as a new therapeutic target in treatment of human cancers.

The effects of environmental aryl hydrocarbon receptor ligands on signaling and cell metabolism in cancer

Dioxin and dioxin-like compounds are chlorinated organic pollutants formed during the manufacturing of other chemicals. Dioxins are ligands of the aryl hydrocarbon receptor (AHR), that induce AHR-mediated biochemical and toxic responses and are persistent in the environment. 2,3,7,8- tetrachlorodibenzo para dioxin (TCDD) is the prototypical AHR ligand and its effects represent dioxins. TCDD induces toxicity, immunosuppression and is a suspected tumor promoter. The role of TCDD in cancer however is debated and context-dependent. Environmental particulate matter, polycyclic aromatic hydrocarbons, perfluorooctane sulfonamide, endogenous AHR ligands, and cAMP signaling activate AHR through TCDD-independent pathways. The effect of activated AHR in cancer is context-dependent. The ability of FDA-approved drugs to modulate AHR activity has sparked interest in their repurposing for cancer therapy. TCDD by interfering with endogenous pathways, and overstimulating other endogenous pathways influences all stages of cancer. Herein we review signaling mechanisms that activate AHR and mechanisms by which activated AHR modulates signaling in cancer including affected metabolic pathways.

Apoptotic and anti-Warburg effect of Morusin via ROS mediated inhibition of FOXM1/c-Myc signaling in prostate cancer cells

Though Morusin is known to induce apoptotic, antiprolifertaive, and autophagic effects through several signaling pathways, the underlying molecular mechanisms of Morusin still remain unclear until now. To elucidate antitumor mechanism of Morusin, cytotoxicity assay, cell cycle analysis, Western blotting, TUNEL assay, RNA interference, immunofluorescense, immunoprecipitation, reactive oxygen species (ROS) measurement, and inhibitor study were applied in this study. Morusin enhanced cytotoxicity, increased the number of TUNEL positive cells, sub-G1 population and induced the cleavages of PARP and caspase3, attenuated the expression of HK2, PKM2, LDH, c-Myc, and Forkhead Box M1 (FOXM1) along with the reduction of glucose, lactate, and ATP in DU145 and PC3 cells. Furthermore, Morusin disrupted the binding of c-Myc and FOXM1 in PC-3 cells, which was supported by String and cBioportal database. Notably, Morusin induced c-Myc degradation mediated by FBW7 and suppressed c-Myc stability in PC3 cells exposed to MG132 and cycloheximide. Also, Morusin generated ROS, while NAC disrupted the capacity of Morusin to reduce the expression of FOXM1, c-Myc, pro-PARP, and pro-caspase3 in PC-3 cells. Taken together, these findings provide scientific evidence that ROS mediated inhibition of FOXM1/c-Myc signaling axis plays a critical role in Morusin induced apoptotic and anti-Warburg effect in prostate cancer cells. Our findings support scientific evidence that ROS mediated inhibition of FOXM1/c-Myc signaling axis is critically involved in apoptotic and anti-Warburg effect of Morusin in prostate cancer cells.

Unraveling MYC's Role in Orchestrating Tumor Intrinsic and Tumor Microenvironment Interactions Driving Tumorigenesis and Drug Resistance

The transcription factor MYC plays a pivotal role in regulating various cellular processes and has been implicated in tumorigenesis across multiple cancer types. MYC has emerged as a master regulator governing tumor intrinsic and tumor microenvironment interactions, supporting tumor progression and driving drug resistance. This review paper aims to provide an overview and discussion of the intricate mechanisms through which MYC influences tumorigenesis and therapeutic resistance in cancer. We delve into the signaling pathways and molecular networks orchestrated by MYC in the context of tumor intrinsic characteristics, such as proliferation, replication stress and DNA repair. Furthermore, we explore the impact of MYC on the tumor microenvironment, including immune evasion, angiogenesis and cancer-associated fibroblast remodeling. Understanding MYC's multifaceted role in driving drug resistance and tumor progression is crucial for developing targeted therapies and combination treatments that may effectively combat this devastating disease. Through an analysis of the current literature, this review's goal is to shed light on the complexities of MYC-driven oncogenesis and its potential as a promising therapeutic target.

The Apoptotic and Anti-Warburg Effects of Brassinin in PC-3 Cells via Reactive Oxygen Species Production and the Inhibition of the c-Myc, SIRT1, and β-Catenin Signaling Axis

Though Brassinin is known to have antiangiogenic, anti-inflammatory, and antitumor effects in colon, prostate, breast, lung, and liver cancers, the underlying antitumor mechanism of Brassinin is not fully understood so far. Hence, in the current study, the apoptotic mechanism of Brassinin was explored in prostate cancer. Herein, Brassinin significantly increased the cytotoxicity and reduced the expressions of pro-Poly ADP-ribose polymerase (PARP), pro-caspase 3, and B-cell lymphoma 2 (Bcl-2) in PC-3 cells compared to DU145 and LNCaP cells. Consistently, Brassinin reduced the number of colonies and increased the sub-G1 population and terminal deoxynucleotidyl transferase (TdT) dUTP Nick-End Labeling (TUNEL)-positive cells in the PC-3 cells. Of note, Brassinin suppressed the expressions of pyruvate kinase-M2 (PKM2), glucose transporter 1 (GLUT1), hexokinase 2 (HK2), and lactate dehydrogenase (LDH) as glycolytic proteins in the PC-3 cells. Furthermore, Brassinin significantly reduced the expressions of SIRT1, c-Myc, and β-catenin in the PC-3 cells and also disrupted the binding of SIRT1 with β-catenin, along with a protein-protein interaction (PPI) score of 0.879 and spearman's correlation coefficient of 0.47 being observed between SIRT1 and β-catenin. Of note, Brassinin significantly increased the reactive oxygen species (ROS) generation in the PC-3 cells. Conversely, ROS scavenger NAC reversed the ability of Brassinin to attenuate pro-PARP, pro-Caspase3, SIRT1, and β-catenin in the PC-3 cells. Taken together, these findings support evidence that Brassinin induces apoptosis via the ROS-mediated inhibition of SIRT1, c-Myc, β-catenin, and glycolysis proteins as a potent anticancer candidate.

The Myc Family and the Metastasis Suppressor NDRG1: Targeting Key Molecular Interactions with Innovative Therapeutics

Cancer is a leading cause of death worldwide, resulting in ∼10 million deaths in 2020. Major oncogenic effectors are the Myc proto-oncogene family, which consists of three members including c-Myc, N-Myc, and L-Myc. As a pertinent example of the role of the Myc family in tumorigenesis, amplification of MYCN in childhood neuroblastoma strongly correlates with poor patient prognosis. Complexes between Myc oncoproteins and their partners such as hypoxia-inducible factor-1α and Myc-associated protein X (MAX) result in proliferation arrest and pro-proliferative effects, respectively. Interactions with other proteins are also important for N-Myc activity. For instance, the enhancer of zest homolog 2 (EZH2) binds directly to N-Myc to stabilize it by acting as a competitor against the ubiquitin ligase, SCFFBXW7, which prevents proteasomal degradation. Heat shock protein 90 may also be involved in N-Myc stabilization since it binds to EZH2 and prevents its degradation. N-Myc downstream-regulated gene 1 (NDRG1) is downregulated by N-Myc and participates in the regulation of cellular proliferation via associating with other proteins, such as glycogen synthase kinase-3β and low-density lipoprotein receptor-related protein 6. These molecular interactions provide a better understanding of the biologic roles of N-Myc and NDRG1, which can be potentially used as therapeutic targets. In addition to directly targeting these proteins, disrupting their key interactions may also be a promising strategy for anti-cancer drug development. This review examines the interactions between the Myc proteins and other molecules, with a special focus on the relationship between N-Myc and NDRG1 and possible therapeutic interventions. SIGNIFICANCE STATEMENT: Neuroblastoma is one of the most common childhood solid tumors, with a dismal five-year survival rate. This problem makes it imperative to discover new and more effective therapeutics. The molecular interactions between major oncogenic drivers of the Myc family and other key proteins; for example, the metastasis suppressor, NDRG1, may potentially be used as targets for anti-neuroblastoma drug development. In addition to directly targeting these proteins, disrupting their key molecular interactions may also be promising for drug discovery.

Natural products target glycolysis in liver disease

Mitochondrial dysfunction plays an important role in the occurrence and development of different liver diseases. Oxidative phosphorylation (OXPHOS) dysfunction and production of reactive oxygen species are closely related to mitochondrial dysfunction, forcing glycolysis to become the main source of energy metabolism of liver cells. Moreover, glycolysis is also enhanced to varying degrees in different liver diseases, especially in liver cancer. Therefore, targeting the glycolytic signaling pathway provides a new strategy for the treatment of non-alcoholic fatty liver disease (NAFLD) and liver fibrosis associated with liver cancer. Natural products regulate many steps of glycolysis, and targeting glycolysis with natural products is a promising cancer treatment. In this review, we have mainly illustrated the relationship between glycolysis and liver disease, natural products can work by targeting key enzymes in glycolysis and their associated proteins, so understanding how natural products regulate glycolysis can help clarify the therapeutic mechanisms these drugs use to inhibit liver disease.

Targeting metabolism by B-raf inhibitors and diclofenac restrains the viability of BRAF-mutated thyroid carcinomas with Hif-1α-mediated glycolytic phenotype

BACKGROUND

B-raf inhibitors (BRAFi) are effective for BRAF-mutated papillary (PTC) and anaplastic (ATC) thyroid carcinomas, although acquired resistance impairs tumour cells' sensitivity and/or limits drug efficacy. Targeting metabolic vulnerabilities is emerging as powerful approach in cancer.

METHODS

In silico analyses identified metabolic gene signatures and Hif-1α as glycolysis regulator in PTC. BRAF-mutated PTC, ATC and control thyroid cell lines were exposed to HIF1A siRNAs or chemical/drug treatments (CoCl2, EGF, HGF, BRAFi, MEKi and diclofenac). Genes/proteins expression, glucose uptake, lactate quantification and viability assays were used to investigate the metabolic vulnerability of BRAF-mutated cells.

RESULTS

A specific metabolic gene signature was identified as a hallmark of BRAF-mutated tumours, which display a glycolytic phenotype, characterised by enhanced glucose uptake, lactate efflux and increased expression of Hif-1α-modulated glycolytic genes. Indeed, Hif-1α stabilisation counteracts the inhibitory effects of BRAFi on these genes and on cell viability. Interestingly, targeting metabolic routes with BRAFi and diclofenac combination we could restrain the glycolytic phenotype and synergistically reduce tumour cells' viability.

CONCLUSION

The identification of a metabolic vulnerability of BRAF-mutated carcinomas and the capacity BRAFi and diclofenac combination to target metabolism open new therapeutic perspectives in maximising drug efficacy and reducing the onset of secondary resistance and drug-related toxicity.

A Novel Assessment of Metabolic Pathways in Peritoneal Metastases from Low-Grade Appendiceal Mucinous Neoplasms

BACKGROUND

There is a paucity of targeted therapies for patients with pseudomyxoma peritonei (PMP) secondary to low-grade appendiceal mucinous neoplasms (LAMNs). Dysregulated metabolism has emerged as a hallmark of cancer, and the relationship of metabolomics and cancer is an area of active scientific exploration. We sought to characterize phenotypic differences found in peritoneal metastases (PM) derived from LAMN versus adenocarcinoma.

METHODS

Tumors were washed with phosphate-buffered saline (PBS), microdissected, then dissociated in ice-cold methanol dried and reconstituted in pyridine. Samples were derivatized in tert-butyldimethylsilyl (TBDMS) and subjected to gas chromatography-coupled mass spectrometry. Metabolites were assessed based on a standard library. RNA sequencing was performed, with pathway and network analyses on differentially expressed genes.

RESULTS

Eight peritoneal tumor samples were obtained and analyzed: LAMNs (4), and moderate to poorly differentiated adenocarcinoma (colon [1], appendix [3]). Decreases in pyroglutamate, fumarate, and cysteine in PM from LAMNs were found compared with adenocarcinoma. Analyses showed the differential gene expression was dominated by the prevalence of metabolic pathways, particularly lipid metabolism. The gene retinol saturase (RETSAT), downregulated by LAMN, was involved in the multiple metabolic pathways that involve lipids. Using network mapping, we found IL1B signaling to be a potential top-level modulation candidate.

CONCLUSIONS

Distinct metabolic signatures may exist for PM from LAMN versus adenocarcinoma. A multitude of genes are differentially regulated, many of which are involved in metabolic pathways. Additional research is needed to identify the significance and applicability of targeting metabolic pathways in the potential development of novel therapeutics for these challenging tumors.

The SIRT1-c-Myc axis in regulation of stem cells

SIRT1 is the most conserved mammalian NAD+-dependent protein deacetylase. Through deacetylation of transcriptional factors and co-factors, this protein modification enzyme is critically involved in metabolic and epigenetic regulation of stem cells, which is functionally important in maintaining their pluripotency and regulating their differentiation. C-Myc, a key member of Myc proton-oncogene family, is a pivotal factor for transcriptional regulation of genes that control acquisition and maintenance of stemness. Previous cancer research has revealed an intriguing positive feedback loop between SIRT1 and c-Myc that is crucial in tumorigenesis. Recent literature has uncovered important functions of this axis in regulation of maintenance and differentiation of stem cells, including pluripotent stem cells and cancer stem cells. This review highlights recent advances of the SIRT1-c-Myc axis in stem cells.

Oxidative phosphorylation is a metabolic vulnerability of endocrine therapy and palbociclib resistant metastatic breast cancers

Resistance to endocrine treatments and CDK4/6 inhibitors is considered a near-inevitability in most patients with estrogen receptor positive breast cancers (ER + BC). By genomic and metabolomics analyses of patients' tumours, metastasis-derived patient-derived xenografts (PDX) and isogenic cell lines we demonstrate that a fraction of metastatic ER + BC is highly reliant on oxidative phosphorylation (OXPHOS). Treatment by the OXPHOS inhibitor IACS-010759 strongly inhibits tumour growth in multiple endocrine and palbociclib resistant PDX. Mutations in the PIK3CA/AKT1 genes are significantly associated with response to IACS-010759. At the metabolic level, in vivo response to IACS-010759 is associated with decreased levels of metabolites of the glutathione, glycogen and pentose phosphate pathways in treated tumours. In vitro, endocrine and palbociclib resistant cells show increased OXPHOS dependency and increased ROS levels upon IACS-010759 treatment. Finally, in ER + BC patients, high expression of OXPHOS associated genes predict poor prognosis. In conclusion, these results identify OXPHOS as a promising target for treatment resistant ER + BC patients.

LSD1 interacting with HSP90 promotes skin wound healing by inducing metabolic reprogramming of hair follicle stem cells through the c-MYC/LDHA axis

It has been demonstrated that hair follicle stem cells (HFSCs) can contribute to wound closure and repair. However, the specific mechanism remains unclear due to the complexity of the wound repair process. Lysine-specific demethylase 1 (LSD1), an important gene for the regulation of stem cell differentiation, has been reported to participate in wound healing regulation. Heat shock protein 90 (HSP90), a chaperone protein, is recently discovered to be a driver gene for wound healing. This study explored the molecular mechanisms by which the binding between LSD1 and HSP90 affects the role of HFSCs during skin wound healing. Following bioinformatics analysis, the key genes acting on HFSCs were identified. The expression of LSD1, HSP90, and c-MYC was found to be upregulated in differentiated HFSCs. Analysis of their binding affinity revealed that LSD1 interacted with HSP90 to enhance the stability of the transcription factor c-MYC. Lactate dehydrogenase A (LDHA) has been documented to be essential for HFSC activation. Therefore, we speculate that LDHA may induce the differentiation of HFSCs through glucose metabolism reprogramming. The results showed that c-MYC activated LDHA activity to promote glycolytic metabolism, proliferation, and differentiation of HFSCs. Finally, in vivo animal experiments further confirmed that LSD1 induced skin wound healing in mice via the HSP90/c-MYC/LDHA axis. From our data, we conclude that LSD1 interacting with HSP90 accelerates skin wound healing by inducing HFSC glycolytic metabolism, proliferation, and differentiation via c-MYC/LDHA axis.

Differential Inhibition of Anaplerotic Pyruvate Carboxylation and Glutaminolysis-Fueled Anabolism Underlies Distinct Toxicity of Selenium Agents in Human Lung Cancer

Past chemopreventive human trials on dietary selenium supplements produced controversial outcomes. They largely employed selenomethionine (SeM)-based diets. SeM was less toxic than selenite or methylseleninic acid (MSeA) to lung cancer cells. We thus investigated the toxic action of these Se agents in two non-small cell lung cancer (NSCLC) cell lines and ex vivo organotypic cultures (OTC) of NSCLC patient lung tissues. Stable isotope-resolved metabolomics (SIRM) using 13C6-glucose and 13C5,15N2-glutamine tracers with gene knockdowns were employed to examine metabolic dysregulations associated with cell type- and treatment-dependent phenotypic changes. Inhibition of key anaplerotic processes, pyruvate carboxylation (PyC) and glutaminolysis were elicited by exposure to MSeA and selenite but not by SeM. They were accompanied by distinct anabolic dysregulation and reflected cell type-dependent changes in proliferation/death/cell cycle arrest. NSCLC OTC showed similar responses of PyC and/or glutaminolysis to the three agents, which correlated with tissue damages. Altogether, we found differential perturbations in anaplerosis-fueled anabolic pathways to underlie the distinct anti-cancer actions of the three Se agents, which could also explain the failure of SeM-based chemoprevention trials.

CDK7 controls E2F- and MYC-driven proliferative and metabolic vulnerabilities in multiple myeloma

Therapeutic targeting of CDK7 has proven beneficial in preclinical studies, yet the off-target effects of currently available CDK7 inhibitors make it difficult to pinpoint the exact mechanisms behind MM cell death mediated by CDK7 inhibition. Here, we show that CDK7 expression positively correlates with E2F and MYC transcriptional programs in cells from patients with multiple myeloma (MM); its selective targeting counteracts E2F activity via perturbation of the cyclin-dependent kinases/Rb axis and impairs MYC-regulated metabolic gene signatures translating into defects in glycolysis and reduced levels of lactate production in MM cells. CDK7 inhibition using the covalent small-molecule inhibitor YKL-5-124 elicits a strong therapeutic response with minimal effects on normal cells, and causes in vivo tumor regression, increasing survival in several mouse models of MM including a genetically engineered mouse model of MYC-dependent MM. Through its role as a critical cofactor and regulator of MYC and E2F activity, CDK7 is therefore a master regulator of oncogenic cellular programs supporting MM growth and survival, and a valuable therapeutic target providing rationale for development of YKL-5-124 for clinical use.

Aspirin induces immunogenic cell death and enhances cancer immunotherapy in colorectal cancer

The use of aspirin is associated with reduced incidence of colorectal cancer (CRC). However, the detailed mechanism remains unclear. In this study, we reported that colon cancer cells treated with aspirin showed the hallmarks of immunogenic cell death (ICD), including surface expression of calreticulin (CRT) and heat shock protein 70 (HSP70). Mechanistically, aspirin induced endoplasmic reticulum (ER) stress in colon cancer cells. In addition, aspirin decreased the expression of the glucose transporters, GLUT3, and reduced the key enzyme of glycolysis, including HK2, PFKM, PKM2 and LDHA. The changes of tumor glycolysis after aspirin treatment were associated with c-MYC downregulation. Moreover, aspirin potentiated the antitumor efficacy of anti-PD-1 antibody and anti-CTLA-4 antibody in CT26 tumors. However, this antitumor activity of aspirin in combination with anti-PD-1 antibody was abolished by the depletion of CD8⁺ T cells. Vaccination with tumor antigens is one of the strategies for activating T-cell response against tumors. Here, we demonstrated that aspirin-treated tumor cells in combination with tumor antigens (AH1 peptide) or protective substituted peptide (A5 peptide) could be served as a potent vaccine to eradicate tumors. Overall, our data indicated that aspirin can be used as an inducer of ICD for CRC therapy.

Prognostic prediction and immunotherapy response analysis of the fatty acid metabolism-related genes in clear cell renal cell carcinoma

Background

Clear cell renal cell carcinoma (ccRCC) is a common urinary cancer. Although diagnostic and therapeutic approaches for ccRCC have been improved, the survival outcomes of patients with advanced ccRCC remain unsatisfactory. Fatty acid metabolism (FAM) has been increasingly recognized as a critical modulator of cancer development. However, the significance of the FAM in ccRCC remains unclear. Herein, we explored the function of a FAM-related risk score in the stratification and prediction of treatment responses in patients with ccRCC.

Methods

First, we applied an unsupervised clustering method to categorize patients from The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) datasets into subtypes and retrieved FAM-related genes from the MSigDB database. We discern differentially expressed genes (DEGs) among different subtypes. Then, we applied univariate Cox regression analysis followed by least absolute shrinkage and selection operator (LASSO) linear regression based on DEGs expression to establish a FAM-related risk score for ccRCC.

Results

We stratified the three ccRCC subtypes based on FAM-related genes with distinct overall survival (OS), clinical features, immune infiltration patterns, and treatment sensitivities. We screened nine genes from the FAM-related DEGs in the three subtypes to establish a risk prediction model for ccRCC. Nine FAM-related genes were differentially expressed in the ccRCC cell line ACHN compared to the normal kidney cell line HK2. High-risk patients had worse OS, higher genomic heterogeneity, a more complex tumor microenvironment (TME), and elevated expression of immune checkpoints. This phenomenon was validated in the ICGC cohort.

Conclusion

We constructed a FAM-related risk score that predicts the prognosis and therapeutic response of ccRCC. The close association between FAM and ccRCC progression lays a foundation for further exploring FAM-related functions in ccRCC.

Re-Shaping the Pancreatic Cancer Tumor Microenvironment: A New Role for the Metastasis Suppressor NDRG1

Pancreatic cancer (PaC) is a highly aggressive disease, with poor response to current treatments and 5-year survival rates of 10-15%. PaC progression is facilitated by its interaction with the complex and multifaceted tumor microenvironment (TME). In the TME, cancer cells and surrounding stromal cells constantly communicate with each other via the secretion and uptake of factors including cytokines, chemokines, growth factors, metabolites, and extracellular vesicles (EVs), reshaping the landscape of PaC. Recent studies demonstrated that the metastasis suppressor N-myc downstream regulated 1 (NDRG1) not only inhibits oncogenic signaling pathways in PaC cells but also alters the communication between PaC cells and the surrounding stroma. In fact, NDRG1 was found to influence the secretome of PaC cells, alter cancer cell metabolism, and interfere with intracellular trafficking and intercellular communication between PaC cells and surrounding fibroblasts. This review will present recent advancements in understanding the role of NDRG1 in PaC progression, with a focus on how this molecule influences PaC-stroma communication and its potential for re-shaping the PaC TME.

Potent carotenoid astaxanthin expands the anti-cancer activity of cisplatin in human prostate cancer cells

Prostate cancer (PCa) is the second most common type of cancer and the sixth cause of death in men worldwide. Radiotherapy and immunotherapy are commonly used in treating PCa, but understanding the crosstalk mechanisms of carcinogenesis and new therapeutic approaches is essential for supporting poor diagnosis and existing therapies. Astaxanthin (ASX) is a member of the xanthophyll family that is an oxygenated derivative of carotenoids whose synthesis is in plant extracts from lycopene. ASX has protective effects on various diseases, such as Parkinson's disease and cancer by showing potent antioxidant and anti-inflammatory properties. However, there is an ongoing need for a detailed investigation of the molecular mechanism of action to expand its therapeutic use. In the present study, we showed the new regulatory role of ASX in PCa cells by affecting the unfolded protein response (UPR) signaling, autophagic activity, epithelial-mesenchymal transition (EMT) and regulating the expression level of angiogenesis-related protein vascular endothelial growth factor A (VEGF-A), proto-oncogene c-Myc and prostate-specific antigen (PSA). Additionally, we determined that it exhibited synergistic action with cisplatin and significantly enhanced apoptotic cell death in PCa cells. Present findings suggest that ASX may be a potent adjuvant therapeutic option in PCa treatment when used alone or combined with chemotherapeutics. Schematic illustration of the biochemical activity of astaxanthin and its combination with cisplatin.

Osteosarcoma tumors maintain intra-tumoral transcriptional heterogeneity during bone and lung colonization

BACKGROUND

Tumors are complex tissues containing collections of phenotypically diverse malignant and nonmalignant cells. We know little of the mechanisms that govern heterogeneity of tumor cells nor of the role heterogeneity plays in overcoming stresses, such as adaptation to different microenvironments. Osteosarcoma is an ideal model for studying these mechanisms-it exhibits widespread inter- and intra-tumoral heterogeneity, predictable patterns of metastasis, and a lack of clear targetable driver mutations. Understanding the processes that facilitate adaptation to primary and metastatic microenvironments could inform the development of therapeutic targeting strategies.

RESULTS

We investigated single-cell RNA-sequencing profiles of 47,977 cells obtained from cell line and patient-derived xenograft models as cells adapted to growth within primary bone and metastatic lung environments. Tumor cells maintained phenotypic heterogeneity as they responded to the selective pressures imposed during bone and lung colonization. Heterogenous subsets of cells defined by distinct transcriptional profiles were maintained within bone- and lung-colonizing tumors, despite high-level selection. One prominent heterogenous feature involving glucose metabolism was clearly validated using immunofluorescence staining. Finally, using concurrent lineage tracing and single-cell transcriptomics, we found that lung colonization enriches for multiple clones with distinct transcriptional profiles that are preserved across cellular generations.

CONCLUSIONS

Response to environmental stressors occurs through complex and dynamic phenotypic adaptations. Heterogeneity is maintained, even in conditions that enforce clonal selection. These findings likely reflect the influences of developmental processes promoting diversification of tumor cell subpopulations, which are retained, even in the face of selective pressures.

Cancer Stem Cells and Prostate Cancer: A Narrative Review

Cancer stem cells (CSCs) are a small and elusive subpopulation of self-renewing cancer cells with the remarkable ability to initiate, propagate, and spread malignant disease. In the past years, several authors have focused on the possible role of CSCs in PCa development and progression. PCa CSCs typically originate from a luminal prostate cell. Three main pathways are involved in the CSC development, including the Wnt, Sonic Hedgehog, and Notch signaling pathways. Studies have observed an important role for epithelial mesenchymal transition in this process as well as for some specific miRNA. These studies led to the development of studies targeting these specific pathways to improve the management of PCa development and progression. CSCs in prostate cancer represent an actual and promising field of research.

The Ubiquitin-Proteasome System in Tumor Metabolism

Metabolic reprogramming, which is considered a hallmark of cancer, can maintain the homeostasis of the tumor environment and promote the proliferation, survival, and metastasis of cancer cells. For instance, increased glucose uptake and high glucose consumption, known as the "Warburg effect," play an essential part in tumor metabolic reprogramming. In addition, fatty acids are harnessed to satisfy the increased requirement for the phospholipid components of biological membranes and energy. Moreover, the anabolism/catabolism of amino acids, such as glutamine, cystine, and serine, provides nitrogen donors for biosynthesis processes, development of the tumor inflammatory environment, and signal transduction. The ubiquitin-proteasome system (UPS) has been widely reported to be involved in various cellular biological activities. A potential role of UPS in the metabolic regulation of tumor cells has also been reported, but the specific regulatory mechanism has not been elucidated. Here, we review the role of ubiquitination and deubiquitination modification on major metabolic enzymes and important signaling pathways in tumor metabolism to inspire new strategies for the clinical treatment of cancer.

Oncogenic FLT3 internal tandem duplication activates E2F1 to regulate purine metabolism in acute myeloid leukaemia

Oncogene FLT3 internal tandem duplication (FLT3-ITD) mutation accounts for 30 % of acute myeloid leukaemia (AML) cases and induces transformation. Previously, we found that E2F transcription factor 1 (E2F1) was involved in AML cell differentiation. Here, we reported that E2F1 expression was aberrantly upregulated in AML patients, especially in AML patients carrying FLT3-ITD. E2F1 knockdown inhibited cell proliferation and increased cell sensitivity to chemotherapy in cultured FLT3-ITD-positive AML cells. E2F1-depleted FLT3-ITD⁺ AML cells lost their malignancy as shown by the reduced leukaemia burden and prolonged survival in NOD-Prkdc^scidIl2rg^em1/Smoc mice receiving xenografts. Additionally, FLT3-ITD-driven transformation of human CD34⁺ hematopoietic stem and progenitor cells was counteracted by E2F1 knockdown. Mechanistically, FLT3-ITD enhanced the expression and nuclear accumulation of E2F1 in AML cells. Further study using chromatin immunoprecipitation-sequencing and metabolomics analyses revealed that ectopic FLT3-ITD promoted the recruitment of E2F1 on genes encoding key enzymatic regulators of purine metabolism and thus supported AML cell proliferation. Together, this study demonstrates that E2F1-activated purine metabolism is a critical downstream process of FLT3-ITD in AML and a potential target for FLT3-ITD⁺ AML patients.

Role and therapeutic targeting of glutamine metabolism in non‑small cell lung cancer (Review)

The Warburg effect indicates that cancer cells survive through glycolysis under aerobic conditions; as such, the topic of cancer metabolism has aroused interest. It is requisite to further explore cancer metabolism, as it helps to simultaneously explain the process of carcinogenesis and guide therapy. The flexible metabolism of cancer cells, which is the result of metabolic reprogramming, can meet the basic needs of cells, even in a nutrition-deficient environment. Glutamine is the most abundant non-essential amino acid in the circulation, and along with glucose, comprise the two basic nutrients of cancer cell metabolism. Glutamine is crucial in non-small cell lung cancer (NSCLC) cells and serves an important role in supporting cell growth, activating signal transduction and maintaining redox homeostasis. In this perspective, the present review aims to provide a new therapeutic strategy of NSCLC through inhibiting the metabolism of glutamine. This review not only summarizes the significance of glutamine metabolism in NSCLC cells, but also enumerates traditional glutamine inhibitors along with new targets. It also puts forward the concept of combination therapy and patient stratification with the aim of comprehensively showing the effect and prospect of targeted glutamine metabolism in NSCLC therapy. This review was completed by searching for keywords including 'glutamine', 'NSCLC' and 'therapy' on PubMed, and screening out articles.

Transcriptional regulatory mechanisms and signaling networks in cancer

Cancer is a general term that refers to a wide range of illnesses that are characterized by the development of aberrant cells that have the capacity to divide uncontrollably, invade, and harm healthy tissue. It is caused by both genetic and epigenetic changes that suppress abnormal proliferation and prevent cells from surviving outside of their normal niches. Complex protein networks are responsible for the development of a suitable environment via multiple cells signaling pathways. The study of these pathways is essential for analysing network context and developing novel cancer therapies. Transcription factors (TFs) are actively involved in gene expression and maintain the combinatorial on-and-off states of the gene. In addition, the TFs regulate cell identity and state; these TFs cooperate to establish cell-type-specific gene expression. In this chapter, we describe the number of transcription factors and their role in the progression of cancer. The knowledge of transcriptional factors and their network is crucial for emphasizing the specific transcriptional addiction and for designing new anticancer therapies.

METTL5 stabilizes c-Myc by facilitating USP5 translation to reprogram glucose metabolism and promote hepatocellular carcinoma progression

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most prevalent cancers in the world, with a high likelihood of metastasis and a dismal prognosis. The reprogramming of glucose metabolism is critical in the development of HCC. The Warburg effect has recently been confirmed to occur in a variety of cancers, including HCC. However, little is known about the molecular biological mechanisms underlying the Warburg effect in HCC cells. In this study, we sought to better understand how methyltransferase 5, N6-adenosine (METTL5) controls the development of HCC and the Warburg effect.

METHODS

In the current study, quantitative real-time polymerase chain reaction and Western blotting were used to detect the expression of METTL5 in HCC tissues and cell lines. Several different cell models and animal models were established to determine the role of METTL5 in glucose metabolism reprogramming and the underlying molecular mechanism of HCC. Glutathione-S-transferase pulldown, coimmunoprecipitation, RNA sequencing, non-targeted metabolomics, polysome profiling, and luciferase reporter assays were performed to investigate the molecular mechanisms of METTL5 in HCC cells.

RESULTS

We discovered that METTL5 drove glucose metabolic reprogramming to promote the proliferation and metastasis of HCC. Mechanistically, upregulation of METTL5 promoted c-Myc stability and thus activated its downstream glycolytic genes lactate dehydrogenase A (LDHA), enolase 1 (ENO1), triosephosphate isomerase 1 (TPI1), solute carrier family 2 member 1 (SLC2A1), and pyruvate kinase M2 (PKM2). The c-Box and ubiquitin binding domain (UBA) regions of ubiquitin specific peptidase 5 (USP5) binded to c-Myc protein and inhibited K48-linked polyubiquitination of c-Myc. Further study revealed that METTL5 controled the USP5 translation process, which in turn regulated the ubiquitination of c-Myc. Furthermore, we identified cAMP responsive element binding protein 1 (CREB1)/P300 as a critical transcriptional regulator of METTL5 that promoted the transcription of METTL5 in HCC. In patient-derived tumor xenograft (PDX) models, adenovirus-mediated knockout of METTL5 had a good antitumor effect and prolonged the survival of PDX-bearing mice.

CONCLUSIONS

These findings point to a novel mechanism by which CREB1/P300-METTL5-USP5-c-Myc controls abnormal glucose metabolism and promotes tumor growth, suggesting that METTL5 is a potential therapeutic target and prognostic biomarker for HCC.

Functional heterogeneity of MCT1 and MCT4 in metabolic reprogramming affects osteosarcoma growth and metastasis

BACKGROUND

Osteosarcoma is the most common primary malignant bone tumor in adolescents and children and prone to develop lung metastasis. Its prognosis has been virtually unimproved over the last few decades, especially in patients with metastases, who suffer from a dismal survival. Recently, increasing attention has been devoted to monocarboxylate transporters-related (MCTs) metabolic reprogramming. However, the role of MCT1 and MCT4 in osteosarcoma progression and the underlying mechanisms remain to be further elucidated.

METHODS

In this study, we established MCT1 and/or MCT4 knockout cell lines by CRISPR/Cas9 genome editing technology. Then, we assessed glycolysis and oxidative phosphorylation capacities by measuring lactate flux and oxygen consumption. We also performed flowcytometry to test circulating tumor cells and PET/CT to evaluate glucose uptake.

RESULTS

MCT1 was found to be involved in both glycolysis and oxidative respiration due to its ability to transport lactate in both directions. MCT1 inhibition significantly reduced circulating tumor cells and distant metastases partially by increasing oxidative stress. MCT4 was primarily related to glycolysis and responsible for lactate export when the concentration of extracellular lactate was high. MCT4 inhibition dramatically suppressed cell proliferation in vitro and impaired tumor growth with reduction of glucose uptake in vivo.

CONCLUSIONS

Our results demonstrate the functional heterogeneity and redundancy of MCT1 and MCT4 in glucose metabolism and tumor progression in osteosarcoma. Thus, combined inhibition of MCT1 and MCT4 may be a promising therapeutic strategy for treating tumors expressing both transporters.

P2RX7 promotes osteosarcoma progression and glucose metabolism by enhancing c-Myc stabilization

BACKGROUND

Osteosarcoma is the most common malignant tumor in bone and its prognosis has reached a plateau in the past few decades. Recently, metabolic reprogramming has attracted increasing attention in the field of cancer research. In our previous study, P2RX7 has been identified as an oncogene in osteosarcoma. However, whether and how P2RX7 promotes osteosarcoma growth and metastasis through metabolic reprogramming remains unexplored.

METHODS

We used CRISPR/Cas9 genome editing technology to establish P2RX7 knockout cell lines. Transcriptomics and metabolomics were performed to explore metabolic reprogramming in osteosarcoma. RT-PCR, western blot and immunofluorescence analyses were used to determine gene expression related to glucose metabolism. Cell cycle and apoptosis were examined by flowcytometry. The capacity of glycolysis and oxidative phosphorylation were assessed by seahorse experiments. PET/CT was carried out to assess glucose uptake in vivo.

RESULTS

We demonstrated that P2RX7 significantly promotes glucose metabolism in osteosarcoma via upregulating the expression of genes related to glucose metabolism. Inhibition of glucose metabolism largely abolishes the ability of P2RX7 to promote osteosarcoma progression. Mechanistically, P2RX7 enhances c-Myc stabilization by facilitating nuclear retention and reducing ubiquitination-dependent degradation. Furthermore, P2RX7 promotes osteosarcoma growth and metastasis through metabolic reprogramming in a predominantly c-Myc-dependent manner.

CONCLUSIONS

P2RX7 plays a key role in metabolic reprogramming and osteosarcoma progression via increasing c-Myc stability. These findings provide new evidence that P2RX7 might be a potential diagnostic and/or therapeutic target for osteosarcoma. Novel therapeutic strategies targeting metabolic reprogramming appear to hold promise for a breakthrough in the treatment of osteosarcoma.

microRNA-627-5p inhibits colorectal cancer cell proliferation, migration and invasion by targeting Wnt2

BACKGROUND

microRNA-627-5p (miR-627-5p) dysregulation has been observed in several cancer types, such as hepatocellular carcinoma, oral squamous cell carcinoma, glioblastoma multiforme, and gastric cancer. The biological function of miR-627-5p in colorectal cancer (CRC) growth and metastasis is yet unclear.

AIM

To investigate the effects of miR-627-5p on the malignant biological properties of colorectal malignant tumour cells by targeting Wnt2.

METHODS

The levels of miR-627-5p in colorectal tumour tissues were assessed in Gene Expression Omnibus datasets. In order to identify Wnt2 transcript expression in CRC tissues, quantitative real-time polymerase chain reaction (qRT-PCR) analysis was used. Luciferase reporter tests were used to explore whether miR-627-5p might potentially target Wnt2. Wnt2 transcript and protein levels were detected in CRC cells with high miR-627-5p expression. To learn more about how miR-627-5p affects CRC development, migration, apoptosis, and invasion, functional experiments were conducted. Cotransfection with the overexpression vector of Wnt2 and miR-627-5p mimics was utilized to verify whether overexpression of Wnt2 could cancel the impact of miR-627-5p in CRC. Western blot and qRT-PCR were conducted to investigate the effects of miR-627-5p on the Wnt/β-catenin signalling pathway.

RESULTS

miR-627-5p was notably decreased in colorectal tumour tissues, while the gene level of Wnt2 was notably upregulated. A dual luciferase reporter assay revealed that miR-627-5p specifically targets the 3’-untranslated regions of Wnt2 and miR-627-5p upregulation markedly reduced the protein and gene expression of Wnt2 in CRC cells. In vitro gain-of-function assays displayed that miR-627-5p overexpression decreased CRC cells’ capabilities to invade, move, and remain viable while increasing apoptosis. Wnt2 overexpression could reverse the suppressive functions of miR-627-5p. Moreover, upregulation of miR-627-5p suppressed the transcript and protein levels of the downstream target factors in the canonical Wnt/β-catenin signalling, such as c-myc, CD44, β-catenin, and cyclinD1.

CONCLUSION

miR-627-5p acts as a critical inhibitory factor in CRC, possibly by directly targeting Wnt2 and negatively modulating the Wnt/β-catenin signalling, revealing that miR-627-5p could be a possible treatment target for CRC.

Oncolytic Avian Reovirus σA-Modulated Upregulation of the HIF-1α/C-myc/glut1 Pathway to Produce More Energy in Different Cancer Cell Lines Benefiting Virus Replication

Our previous reports proved that the structural protein σA of avian reovirus (ARV) is an energy activator which can regulate cellular metabolism that is essential for virus replication. This study has further demonstrated that the ARV protein σA is able to upregulate the HIF-1α/myc/glut1 pathway in three cancer cell lines (A549, B16-F10, and HeLa) to alter the metabolic pathway of host cells. Quantitative real-time RT-PCR and Western blotting results have revealed that σA protein could enhance both mRNA and the protein levels of HIF-1α, c-myc, and glut1 in these cancer cell lines. In this work, ATeam immunofluorescence staining was used to reveal that knockdown of HIF-1α, c-myc, and glut1 by shRNAs decreased cellular ATP levels. Our data reveal that the ARV σA protein can downregulate lactate fermentation and upregulate glutaminolysis. The σA protein upregulates glutaminase, which converts glutamate into the TCA cycle intermediate α-ketoglutarate, activating the TCA cycle. In the lactate fermentation pathway, ARV σA protein suppresses lactate dehydrogenase A (LDHA), implying the Warburg effect does not occur in these cancer cell lines. This study provides a novel finding revealing that ARV σA protein upregulates glycolysis and glutaminolysis to produce energy using the HIF-1α/c-myc/glut1 pathway to benefit virus replication in these cancer cell lines.

Engineering lactate-modulating nanomedicines for cancer therapy

Lactate in tumors has long been considered "metabolic junk" derived from the glycolysis of cancer cells and utilized only as a biomarker of malignancy, but is presently believed to be a pivotal regulator of tumor development, maintenance and metastasis. Indeed, tumor lactate can be a "fuel" for energy supply and functions as a signaling molecule, which actively contributes to tumor progression, angiogenesis, immunosuppression, therapeutic resistance, etc., thus providing promising opportunities for cancer treatment. However, the current approaches for regulating lactate homeostasis with available agents are still challenging, which is mainly due to the short half-life, low bioavailability and poor specificity of these agents and their unsatisfactory therapeutic outcomes. In recent years, lactate modulation nanomedicines have emerged as a charming and efficient strategy for fighting cancer, which play important roles in optimizing the delivery of lactate-modulating agents for more precise and effective modulation and treatment. Integrating specific lactate-modulating functions in diverse therapeutic nanomedicines may overcome the intrinsic restrictions of different therapeutic modalities by remodeling the pathological microenvironment for achieving enhanced cancer therapy. In this review, the most recent advances in the engineering of functional nanomedicines that can modulate tumor lactate for cancer therapy are summarized and discussed, and the fundamental mechanisms by which lactate modulation benefits various therapeutics are elucidated. Finally, the challenges and perspectives of this emerging strategy in the anti-tumor field are highlighted.

LDHA as a regulator of T cell fate and its mechanisms in disease

T cells are the main force of anti-infection and antitumor and are also involved in autoimmune diseases. During the development of these diseases, T cells need to rapidly produce large amounts of energy to satisfy their activation, proliferation, and differentiation. In this review, we introduced lactate dehydrogenase A(LDHA), predominantly involved in glycolysis, which provides energy for T cells and plays a dual role in disease by mediating lactate production, non-classical enzyme activity, and oxidative stress. Mechanistically, the signaling molecule can interact with the LDHA promoter or regulate LDHA activity through post-translational modifications. These latest findings suggest that modulation of LDHA may have considerable therapeutic effects in diseases where T-cell activation is an important pathogenesis.

USP22 Contributes to Chemoresistance, Stemness, and EMT Phenotype of Triple-Negative Breast Cancer Cells by egulating the Warburg Effect via c-Myc Deubiquitination

BACKGROUND

Ubiquitin-specific protease 22 (USP22) has been implicated in the progression of breast cancer, while its regulatory functions in triple-negative breast cancer (TNBC) have been rarely reported. This study aimed to elucidate the effect and mechanism of USP22 on the malignant phenotype of TNBC cells.

MATERIALS AND METHODS

The expression of USP22, stemness genes, and EMT-related markers were analyzed by RT-qPCR and/or Western blotting. Cell stemness was determined by cell spheroid formation, flow cytometry for CD44+/CD24-, and extreme limiting dilution analysis. Cell proliferation and cisplatin (DDP) chemoresistance of TNBC cells were assessed by CCK-8 assay and xenograft model. Glycolysis was measured by Seahorse assay. The mechanism underlying the role of USP22 was explored by Co-immunoprecipitation, ubiquitination assay, and cycloheximide-chase analysis.

RESULTS

USP22 expression was positively correlated with DDP resistance in TNBC patients and cells. The proliferation, spheroid number, CD44+/CD24- cells, the expression of stemness genes and EMT-related markers in TNBC cells were significantly elevated after USP22 was overexpressed; however, these parameters in DDP-resistant TNBC (TNBC/DDP) cells were significantly reduced after silencing USP22. USP22 overexpression enhanced the extracellular acidification rate, proliferation, spheroid number, CD44+/CD24- cell number, and the expression of stemness genes and EMT-related markers in TNBC/DDP cells, while these effects were restrained by glycolysis inhibitors. Mechanically, USP22 interacted with c-Myc to promote its stabilization by deubiquitination in TNBC cells. Silencing of USP22 increased DDP sensitivity and survival of mice bearing TNBC.

CONCLUSION

USP22 contributes to chemoresistance, stemness, and EMT phenotype of TNBC cells by suppressing the glycolysis via c-Myc deubiquitination.

Chromosomal Instability as Enabling Feature and Central Hallmark of Breast Cancer

Chromosomal instability (CIN) has become a topic of great interest in recent years, not only for its implications in cancer diagnosis and prognosis but also for its role as an enabling feature and central hallmark of cancer. CIN describes cell-to-cell variation in the number or structure of chromosomes in a tumor population. Although extensive research in recent decades has identified some associations between CIN with response to therapy, specific associations with other hallmarks of cancer have not been fully evidenced. Such associations place CIN as an enabling feature of the other hallmarks of cancer and highlight the importance of deepening its knowledge to improve the outcome in cancer. In addition, studies conducted to date have shown paradoxical findings about the implications of CIN for therapeutic response, with some studies showing associations between high CIN and better therapeutic response, and others showing the opposite: associations between high CIN and therapeutic resistance. This evidences the complex relationships between CIN with the prognosis and response to treatment in cancer. Considering the above, this review focuses on recent studies on the role of CIN in cancer, the cellular mechanisms leading to CIN, its relationship with other hallmarks of cancer, and the emerging therapeutic approaches that are being developed to target such instability, with a primary focus on breast cancer. Further understanding of the complexity of CIN and its association with other hallmarks of cancer could provide a better understanding of the cellular and molecular mechanisms involved in prognosis and response to treatment in cancer and potentially lead to new drug targets.

UBE2K promotes the malignant progression of hepatocellular carcinoma by regulating c-Myc

Hepatocellular carcinoma (HCC) is a serious threat to human health and life due to its high morbidity and mortality. Ubiquitin-conjugating enzymes are players in the ubiquitin proteasome system and are responsible for a great number of physiological activities in cells. The action of ubiquitin-conjugating enzyme UBE2K in HCC has not been reported. Therefore, we studied the function and role of UBE2K in the malignant progression of HCC. An analysis of UBE2K expression in HCC cells was performed using RT-qPCR and protein immunoblotting. CCK-8, Transwell and sphere formation assays were used to identify the potential effects of UBE2K in HCC cell proliferation, migration and stemness property. RT-qPCR, and protein immunoblotting experiments was taken to explore the regulation between UBE2K and c-Myc. Here, we discovered that UBE2K expression was elevated in HCC cells, and elevated UBE2K predicts worse prognosis for HCC patients. Functionally, UBE2K promote, while UBE2K knockdown suppressed cell proliferation, migration and stemness property of HCC cells. Furthermore, c-Myc was identified as a downstream target of UBE2K. Moreover, functional rescue experiments finally proved that UBE2K facilitates the malignant progression of HCC cells by upregulating c-Myc. We clarified through in vivo experiments that UBE2K expression promotes tumor growth in HCC. Taken together, our study results proved the molecular regulation of UBE2K and c-Myc in HCC and the oncogenic role of UBE2K/c-Myc axis in HCC progression, thus it provides a promising molecular target for the diagnosis and treatment of HCC.

Liver Microenvironment Response to Prostate Cancer Metastasis and Hormonal Therapy

Prostate cancer-associated deaths arise from disease progression and metastasis. Metastasis to the liver is associated with the worst clinical outcomes for prostate cancer patients, and these metastatic tumors can be particularly resistant to the currently widely used chemotherapy and hormonal therapies, such as anti-androgens which block androgen synthesis or directly target the androgen receptor. The incidence of liver metastases is reportedly increasing, with a potential correlation with use of anti-androgen therapies. A key player in prostate cancer progression and therapeutic response is the microenvironment of the tumor(s). This is a dynamic and adaptive collection of cells and proteins, which impart signals and stimuli that can alter biological processes within prostate cancer cells. Investigation in the prostate primary site has demonstrated that cells of the microenvironment are also responsive to hormones and hormonal therapies. In this review, we collate information about what happens when cancer moves to the liver: the types of prostate cancer cells that metastasize there, the response of resident mesenchymal cells of the liver, and how the interactions between the cancer cells and the microenvironment may be altered by hormonal therapy.

Regulation of Normal and Neoplastic Proliferation and Metabolism by the Extended Myc Network

The Myc Network, comprising a small assemblage of bHLH-ZIP transcription factors, regulates many hundreds to thousands of genes involved in proliferation, energy metabolism, translation and other activities. A structurally and functionally related set of factors known as the Mlx Network also supervises some of these same functions via the regulation of a more limited but overlapping transcriptional repertoire. Target gene co-regulation by these two Networks is the result of their sharing of three members that suppress target gene expression as well as by the ability of both Network's members to cross-bind one another's consensus DNA sites. The two Networks also differ in that the Mlx Network's control over transcription is positively regulated by several glycolytic pathway intermediates and other metabolites. These distinctive properties, functions and tissue expression patterns potentially allow for sensitive control of gene regulation in ways that are differentially responsive to environmental and metabolic cues while allowing for them to be both rapid and of limited duration. This review explores how such control might occur. It further discusses how the actual functional dependencies of the Myc and Mlx Networks rely upon cellular context and how they may differ between normal and neoplastic cells. Finally, consideration is given to how future studies may permit a more refined understanding of the functional interrelationships between the two Networks.

Alteration of Cellular Energy Metabolism through LPAR2-Axin2 Axis in Gastric Cancer

Lysophosphatidic acid (LPA), a multifunctional endogenous phospholipid, plays a vital role in cellular homeostasis and the malignant behavior of cancer cells through G-protein-coupled receptors. However, the role of LPA in β-catenin-mediated gastric cancer is unknown. Here, we have noted the high expression of LPAR2 in human gastric cancer tissues, and that LPA treatment significantly increased the proliferation, migration, and invasion of human gastric cancer cells. Results from our biochemical experiments showed that an LPA exposure increased the expression of β-catenin and its nuclear localization, increased the phosphorylation of glycogen synthase kinase 3β (GSK-3β), decreased the expression of Axin2, and increased the expression of the target genes of the β-catenin signaling pathway. The LPA2 receptor (LPAR2) antagonist significantly reduced the LPA-induced nuclear localization of β-catenin, the primary signaling event. The knockdown of LPAR2 in the gastric cancer cell lines robustly reduced the LPA-induced β-catenin activity. An LPA exposure increased the ATP production by both oxidative phosphorylation and glycolysis, and this effect was abrogated with the addition of an LPAR2 antagonist and XAV393, which stabilizes the Axin and inhibits the β-catenin signaling pathway. Based on our findings, the possibility that LPA contributes to gastric cancer initiation and progression through the β-catenin signaling pathway as well as by the dysregulation of the energy metabolism via the LPAR2 receptor and Axin2, respectively, provides a novel insight into the mechanism of and possible therapeutic targets of gastric cancer.

NCAPD3 enhances Warburg effect through c-myc and E2F1 and promotes the occurrence and progression of colorectal cancer

Background

NCAPD3 is one of the three non-SMC subunits of condensin II complex, which plays an important role in the chromosome condensation and segregation during mitosis. Notably, elevated levels of NCAPD3 are found in many somatic cancers. However, the clinical role, biological functions of NCAPD3 in cancers especially in colorectal cancer (CRC) and the underlying molecular mechanisms remain poorly elucidated.

Methods

Clinical CRC and adjacent normal tissues were used to confirm the expression of NCAPD3. The association of NCAPD3 expression with clinicopathological characteristics and patient outcomes were analyzed by using online database. In vivo subcutaneous tumor xenograft model, NCAPD3 gene knockout following azoxymethane (AOM)/dextran sodium sulfate (DSS)-induced tumor mouse model, Co-IP, western blot, qRT-PCR, IHC, ChIP assays and cell functional assays were used to investigate the biological functions of NCAPD3 in CRC and the underlying molecular mechanisms.

Results

NCAPD3 was overexpressed in CRC tissues and positively correlated with poor prognosis of CRC patients. NCAPD3 knockout suppressed CRC development in AOM/DSS induced and xenograft mice models. Moreover, we found that NCAPD3 promoted aerobic glycolysis in CRC. Mechanistically, NCAPD3 up-regulated the level of c-Myc and interacted with c-Myc to recruit more c-Myc to the gene promoter of its downstream glycolytic regulators GLUT1, HK2, ENO1, PKM2 and LDHA, and finally enhanced cellular aerobic glycolysis. Also, NCAPD3 increased the level of E2F1 and interacted with E2F1 to recruit more E2F1 to the promoter regions of PDK1 and PDK3 genes, which resulted in the inhibition of PDH activity and TCA cycle.

Conclusions

Our data demonstrated that NCAPD3 promoted glucose metabolism reprogramming and enhanced Warburg effect in colorectal tumorigenesis and CRC progression. These findings reveal a novel mechanism underlying NCAPD3 mediated CRC cell growth and provide new targets for CRC treatment.

Modulation of immunosuppressive cells and noncoding RNAs as immunotherapy in osteosarcoma

The most common bone cancer is osteosarcoma (OS), which mostly affects children and teenagers. Early surgical resection combined with chemotherapy significantly improves the prognosis of patients with OS. Existing chemotherapies have poor efficacy in individuals with distant metastases or inoperable resection, and these patients may respond better to novel immunotherapies. Immune escape, which is mediated by immunosuppressive cells in the tumour microenvironment (TME), is a major cause of poor OS prognosis and a primary target of immunotherapy. Myeloid-derived suppressor cells, regulatory T cells, and tumour-associated macrophages are the main immunosuppressor cells, which can regulate tumorigenesis and growth on a variety of levels through the interaction in the TME. The proliferation, migration, invasion, and epithelial-mesenchymal transition of OS cells can all be impacted by the expression of non-coding RNAs (ncRNAs), which can also influence how immunosuppressive cells work and support immune suppression in TME. Interferon, checkpoint inhibitors, cancer vaccines, and engineered chimeric antigen receptor (CAR-T) T cells for OS have all been developed using information from studies on the metabolic properties of immunosuppressive cells in TME and ncRNAs in OS cells. This review summarizes the regulatory effect of ncRNAs on OS cells as well as the metabolic heterogeneity of immunosuppressive cells in the context of OS immunotherapies.

Nanotherapeutics in autophagy: a paradigm shift in cancer treatment

Autophagy is a catabolic process in which an organism responds to its nutrient or metabolic emergencies. It involves the degradation of cytoplasmic proteins and organelles by forming double-membrane vesicles called "autophagosomes." They sequester cargoes, leading them to degradation in the lysosomes. Although autophagy acts as a protective mechanism for maintaining homeostasis through cellular recycling, it is ostensibly a cause of certain cancers, but a cure for others. In other words, insufficient autophagy, due to genetic or cellular dysfunctions, can lead to tumorigenesis. However, many autophagy modulators are developed for cancer therapy. Diverse nanoparticles have been documented to induce autophagy. Also, the highly stable nanoparticles show blockage to autophagic flux. In this review, we revealed a general mechanism by which autophagy can be induced or blocked via nanoparticles as well as several studies recently performed to prove the stated fact. In addition, we have also elucidated the paradoxical roles of autophagy in cancer and how their differential role at different stages of various cancers can affect its treatment outcomes. And finally, we summarize the breakthroughs in cancer disease treatments by using metallic, polymeric, and liposomal nanoparticles as potent autophagy modulators.

A combination of novel NSC small molecule inhibitor along with doxorubicin inhibits proliferation of triple-negative breast cancer through metabolic reprogramming

Treatment of patients with triple-negative breast cancer (TNBC) has been challenging due to the absence of well-defined molecular targets and the highly invasive and proliferative nature of TNBC cells. Current treatments against TNBC have shown little promise due to high recurrence rate in patients. Consequently, there is a pressing need for novel and efficacious therapies against TNBC. Here, we report the discovery of a novel small molecule inhibitor (NSC33353) with potent anti-tumor activity against TNBC cells. The anti-proliferative effects of this small molecule inhibitor were determined using 2D and 3D cell proliferation assays. We found that NSC33353 significantly reduces the proliferation of TNBC cells in these assays. Using proteomics, next generation sequencing (NGS), and gene enrichment analysis, we investigated global regulatory pathways affected by this compound in TNBC cells. Proteomics data indicate a significant metabolic reprograming affecting both glycolytic enzymes and energy generation through oxidative phosphorylation. Subsequently, using metabolic (Seahorse) and enzymatic assays, we validated our proteomics and NGS analysis findings. Finally, we showed the inhibitory and anti-tumor effects of this small molecule in vitro and confirmed its inhibitory activity in vivo. Doxorubicin is one of the most effective agents in the treatment of TNBC and resistance to this drug has been a major problem. We show that the combination of NSC33353 and doxorubicin suppresses the growth of TNBC cells synergistically, suggesting that NSC33353 enhances TNBC sensitivity to doxorubicin. In summary, our data indicate that the small molecule inhibitor, NSC33353, exhibits anti-tumor activity in TNBC cells, and works in a synergistic fashion with a well-known chemotherapeutic agent.

Natural products targeting glycolysis in cancer

Many energy metabolism pathways exist in cancer, including glycolysis, amino acid metabolism, fatty acid oxidation, and mitochondrial respiration. Tumor cells mainly generate energy through glycolysis to maintain growth and biosynthesis of tumor cells under aerobic conditions. Natural products regulate many steps in glycolysis and targeting glycolysis using natural products is a promising approach to cancer treatment. In this review, we exemplify the relationship between glycolysis and tumors, demonstrate the natural products that have been discovered to target glycolysis for cancer treatment and clarify the mechanisms involved in their actions. Natural products, such as resveratrol mostly found in red grape skin, licochalcone A derived from root of Glycyrrhiza inflate, and brusatol found in Brucea javanica and Brucea mollis, largely derived from plant or animal material, can affect glycolysis pathways in cancer by targeting glycolytic enzymes and related proteins, oncogenes, and numerous glycolytic signal proteins. Knowledge of how natural products regulate aerobic glycolysis will help illuminate the mechanisms by which these products can be used as therapeutics to inhibit cancer cell growth and regulate cellular metabolism. Systematic Review Registration: https://pubmed.ncbi.nlm.nih.gov/, https://clinicaltrials.gov/, http://lib.zzu.edu.cn/.

Metabolic Pathways, Enzymes, and Metabolites: Opportunities in Cancer Therapy

Metabolic reprogramming enables cancer cells to proliferate and produce tumor biomass under a nutrient-deficient microenvironment and the stress of metabolic waste. A cancer cell adeptly undergoes a variety of adaptations in metabolic pathways and differential expression of metabolic enzyme genes. Metabolic adaptation is mainly determined by the physiological demands of the cancer cell of origin and the host tissue. Numerous metabolic regulators that assist cancer cell proliferation include uncontrolled anabolism/catabolism of glucose metabolism, fatty acids, amino acids metabolism, nucleotide metabolism, tumor suppressor genes, microRNAs, and many regulatory enzymes and genes. Using this paradigm, we review the current understanding of metabolic reprogramming in tumors and discuss the new strategies of cancer metabolomics that can be tapped into for cancer therapeutics.

Correlation of Glucose Metabolism with Cancer and Intervention with Traditional Chinese Medicine

Cancer is a complex disease with several distinct characteristics, referred to as “cancer markers” one of which is metabolic reprogramming, which is a common feature that drives cancer progression. Over the last ten years, researchers have focused on the reprogramming of glucose metabolism in cancer. In cancer, the oxidative phosphorylation metabolic pathway is converted into the glycolytic pathway in order to meet the growth requirements of cancer cells, thereby creating a microenvironment that promotes cancer progression. The precise mechanism of glucose metabolism in cancer cells is still unknown, but it is thought to involve the aberrant levels of metabolic enzymes, the influence of the tumor microenvironment (TME), and the activation of tumor-promoting signaling pathways. It is suggested that glucose metabolism is strongly linked to cancer progression because it provides energy to cancer cells and interferes with antitumor drug pharmacodynamics. Therefore, it is critical to unravel the mechanism of glucose metabolism in tumors in order to gain a better understanding of tumorigenesis and to lay the groundwork for future research into the identification of novel diagnostic markers and therapeutic targets for cancer treatment. Traditional Chinese Medicine (TCM) has the characteristics of multiple targets, multiple components, and less toxic side effects and has unique advantages in tumor treatment. In recent years, researchers have found that a variety of Chinese medicine monomers and compound recipes play an antitumor role by interfering with the reprogramming of tumor metabolism. The underlying mechanisms of metabolism reprogramming of tumor cells and the role of TCM in regulating glucose metabolism are reviewed in this study, so as to provide a new idea for antitumor research in Chinese medicine.