The c-Myc-LDHA axis positively regulates aerobic glycolysis and promotes tumor progression in pancreatic cancer

TFAIP6 facilitates hepatocellular carcinoma cell glycolysis through upregulating c-myc/PKM2 axis

Background

Hepatocellular carcinoma (HCC) is the most prevalent liver cancer. Despite of the improvement of therapies, the durable response rate and survival benefit are still limited for HCC patients. It's urgent to clarify the molecular mechanisms and find therapeutic strategies to improve the clinical outcome. TNFα-stimulated gene-6 (TNFAIP6) plays a critical role in the prognosis of various tumors, but its roles in HCC are still unclear.

Methods

Quantitative real-time PCR (qRT-PCR) and immunohistochemistry (IHC) analysis were employed to evaluate the clinical relevance of TNFAIP6 expressions in HCC patients. Cell counting kit-8 (CCK-8), Edu assay, and transwell assay were performed to evaluate the malignancy of HCC cells. Glucose uptake, lactate production, ATP production, extracellular acidification rate (ECAR) by Seahorse XF analyzer were employed to evaluate the role of TNFAIP6 in the regulation of aerobic glycolysis. The expressions of key proteins involved in glycolysis were examined by Western blot. Co-immunoprecipitation (Co-IP) and chromatin immunoprecipitation (ChIP) were used for protein-protein interactions or protein-RNA interactions respectively. Knockdown and overexpression of TNFAIP6 in HCC cells were employed for analyzing the functions of TNFAIP6 in HCC.

Results

TNFAIP6 was significantly upregulated in HCC and predicted a poor clinical prognosis. Knockdown of TNFAIP6 inhibited in vitro cell proliferation, invasion, migration, as well as glycolysis in HCC cells. Mechanistically, we clarified that TNFAIP6 interacted with heterogeneous nuclear ribonucleoprotein C (HNRNPC), stabilized c-Myc mRNA and upregulated pyruvate kinase M2 (PKM2) to promote glycolysis.

Conclusions

Our study reveals a molecular mechanism by which TNFAIP6 promotes aerobic glycolysis, which is beneficial for malignance of HCC and provides a potential clinical therapy for disease management.

Transcriptional regulation and post-translational modifications in the glycolytic pathway for targeted cancer therapy

Cancer cells largely rely on aerobic glycolysis or the Warburg effect to generate essential biomolecules and energy for their rapid growth. The key modulators in glycolysis including glucose transporters and enzymes, e.g. hexokinase 2, enolase 1, pyruvate kinase M2, lactate dehydrogenase A, play indispensable roles in glucose uptake, glucose consumption, ATP generation, lactate production, etc. Transcriptional regulation and post-translational modifications (PTMs) of these critical modulators are important for signal transduction and metabolic reprogramming in the glycolytic pathway, which can provide energy advantages to cancer cell growth. In this review we recapitulate the recent advances in research on glycolytic modulators of cancer cells and analyze the strategies targeting these vital modulators including small-molecule inhibitors and microRNAs (miRNAs) for targeted cancer therapy. We focus on the regulation of the glycolytic pathway at the transcription level (e.g., hypoxia-inducible factor 1, c-MYC, p53, sine oculis homeobox homolog 1, N6-methyladenosine modification) and PTMs (including phosphorylation, methylation, acetylation, ubiquitination, etc.) of the key regulators in these processes. This review will provide a comprehensive understanding of the regulation of the key modulators in the glycolytic pathway and might shed light on the targeted cancer therapy at different molecular levels.

Synergy between BRD9- and IKZF3-Targeting as a Therapeutic Strategy for Multiple Myeloma

Progress in the treatment of multiple myeloma (MM) has resulted in improvement in the survival rate. However, there is still a need for more efficacious and tolerated therapies. We and others have shown that bromodomain-containing protein 9 (BRD9), a member of the non-canonical SWI/SNF chromatin remodeling complex, plays a role in MM cell survival, and targeting BRD9 selectively blocks MM cell proliferation and synergizes with IMiDs. We found that synergy in vitro is associated with the downregulation of MYC and Ikaros proteins, including IKZF3, and overexpression of IKZF3 or MYC could partially reverse synergy. RNA-seq analysis revealed synergy to be associated with the suppression of pathways associated with MYC and E2F target genes and pathways, including cell cycle, cell division, and DNA replication. Stimulated pathways included cell adhesion and immune and inflammatory response. Importantly, combining IMiD treatment and BRD9 targeting, which leads to the downregulation of MYC protein and upregulation of CRBN protein, was able to override IMiD resistance of cells exposed to iberdomide in long-term culture. Taken together, our results support the notion that combination therapy based on agents targeting BRD9 and IKZF3, two established dependencies in MM, represents a promising novel therapeutic strategy for MM and IMiD-resistant disease.

Oncogenic MORC2 in cancer development and beyond

Microrchidia CW-type zinc finger 2 (MORC2) is a member of the MORC superfamily of nuclear proteins. Growing evidence has shown that MORC2 not only participates in gene transcription and chromatin remodeling but also plays a key in human disease and tumor development by regulating the expression of downstream oncogenes or tumor suppressors. The present review provides an updated overview of MORC2 in the aspect of cancer hallmark and therapeutic resistance and summarizes its upstream regulators and downstream target genes. This systematic review may provide a favorable theoretical basis for emerging players of MORC2 in tumor development and new insight into the potential clinical application of basic science discoveries in the future.

Comprehensive study of clinicopathological and immune cell infiltration and lactate dehydrogenase expression in patients with thymic epithelial tumours

BACKGROUND

Lactate dehydrogenase (LDH) has emerged as a promising biomarker for cancer. However, the current understanding of LDH and circulating LDH expression in thymic epithelial tumour (TET) is lacking.

METHODS

A comprehensive literature review and meta-analysis were performed to evaluate the clinical significance of circulating LDH levels in patients with TET. Circulating LDH levels were measured using a laboratory analyser (Cobas8000, Roche, Basel, Switzerland). The maximum standardised uptake value (SUVmax) was determined in patients who underwent whole-body 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT). Multiplex immunohistochemistry (IHC) was performed using a commercially available kit (Opal 6-plex Detection Kit, Akoya Biosciences, Marlborough, MA, USA) and slide scanner (Slideview VS200, Olympus, Tokyo, Japan). All statistical analyses were performed using SPSS (IBM Corp., Armonk, NY, USA) and Prism version 9.0 (GraphPad Inc., San Diego, CA, USA). Differences with p < 0.05 were considered to be statistically significant.

RESULTS

Meta-analysis revealed that elevated circulating serum levels of LDH predicted poor prognosis in patients with TET. Circulating levels of LDH were analysed in the serum of 313 patients with TET and 87 with benign mediastinal mass. The mean circulating LDH level in patients with thymic carcinoma (TC) was significantly higher than that in those with thymoma (TM) and the benign group (p < 0.001). Expression levels of circulating LDH were significantly reduced in postoperative samples compared with that in preoperative samples (p < 0.05). Receiver operating characteristic (ROC) curve analysis for diagnosing TC yielded an area under the curve of 0.74, with a sensitivity of 54 % and specificity of 86 %. Furthermore, patients with TC exhibited higher 18F-FDG PET/CT SUVmax values compared to those with TM. Correlation analysis demonstrated a positive association between SUVmax values and circulating LDH levels. In addition, the percentages of LDH-positive cells in TC and type B1 TM tissues were higher than those in other subtypes of TM, and a significant positive correlation between the percentages of LDH-positive and CD20-positive cells was detected in patients with TET (p < 0.05).

CONCLUSION

Circulating serum LDH level may serve as a non-invasive biomarker for the diagnosis and prognosis of TET. The relationship between LDH expression and immune cell infiltration merits further regarding its application in companion diagnosis for immunotherapy.

Combined inhibition of pyruvate dehydrogenase kinase 1 and lactate dehydrogenase a induces metabolic and signaling reprogramming and enhances lung adenocarcinoma cell killing

Lung adenocarcinoma (LUAD) is one of the most prevalent and aggressive types of lung cancer. Metabolic reprogramming plays a critical role in the development and progression of LUAD. Pyruvate dehydrogenase kinase 1 (PDK1) and lactate dehydrogenase A (LDHA) are two key enzymes involved in glucose metabolism, whilst their aberrant expressions are often associated with tumorigenesis. Herein, we investigated the anticancer effects of combined inhibition of PDK1 and LDHA in LUAD in vitro and in vivo and its underlying mechanisms of action. The combination of a PDK1 inhibitor, 64, and a LDHA inhibitor, NHI-Glc-2, led to a synergistic growth inhibition in 3 different LUAD cell lines and more than additively suppressed tumor growth in the LUAD xenograft H1975 model. This combination also inhibited cellular migration and colony formation, while it induced a metabolic shift from glycolysis to oxidative phosphorylation (OXPHOS) resulting in mitochondrial depolarization and apoptosis in LUAD cells. These effects were related to modulation of multiple cell signaling pathways, including AMPK, RAS/ERK, and AKT/mTOR. Our findings demonstrate that simultaneous inhibition of multiple glycolytic enzymes (PDK1 and LDHA) is a promising novel therapeutic approach for LUAD.

The role of endoplasmic reticulum stress in promoting aerobic glycolysis in cancer cells: An overview

Aerobic glycolysis, also known as the Warburg effect, is a metabolic phenomenon frequently observed in cancer cells, characterized by the preferential utilization of glucose through glycolysis, even under normal oxygen conditions. This metabolic shift provides cancer cells with a proliferative advantage and supports their survival and growth. While the Warburg effect has been extensively studied, the underlying mechanisms driving this metabolic adaptation in cancer cells remain incompletely understood. In recent years, emerging evidence has suggested a potential link between endoplasmic reticulum (ER) stress and the promotion of aerobic glycolysis in cancer cells. The ER is a vital organelle involved in protein folding, calcium homeostasis, and lipid synthesis. Various cellular stresses, such as hypoxia, nutrient deprivation, and accumulation of misfolded proteins, can lead to ER stress. In response, cells activate the unfolded protein response (UPR) to restore ER homeostasis. However, prolonged or severe ER stress can activate alternative signaling pathways that modulate cellular metabolism, including the promotion of aerobic glycolysis. This review aims to provide an overview of the current understanding regarding the influence of ER stress on aerobic glycolysis in cancer cells to shed light on the complex interplay between ER stress and metabolic alterations in cancer cells. Understanding the intricate relationship between ER stress and the promotion of aerobic glycolysis in cancer cells may provide valuable insights for developing novel therapeutic strategies targeting metabolic vulnerabilities in cancer.

E-box binding transcription factors in cancer

E-boxes are important regulatory elements in the eukaryotic genome. Transcription factors can bind to E-boxes through their basic helix-loop-helix or zinc finger domain to regulate gene transcription. E-box-binding transcription factors (EBTFs) are important regulators of development and essential for physiological activities of the cell. The fundamental role of EBTFs in cancer has been highlighted by studies on the canonical oncogene MYC, yet many EBTFs exhibit common features, implying the existence of shared molecular principles of how they are involved in tumorigenesis. A comprehensive analysis of TFs that share the basic function of binding to E-boxes has been lacking. Here, we review the structure of EBTFs, their common features in regulating transcription, their physiological functions, and their mutual regulation. We also discuss their converging functions in cancer biology, their potential to be targeted as a regulatory network, and recent progress in drug development targeting these factors in cancer therapy.

Rewired Metabolism Caused by the Oncogenic Deregulation of MYC as an Attractive Therapeutic Target in Cancers

MYC is one of the most deregulated oncogenes on multiple levels in cancer. As a node transcription factor, MYC plays a diverse regulatory role in many cellular processes, including cell cycle and metabolism, both in physiological and pathological conditions. The relentless growth and proliferation of tumor cells lead to an insatiable demand for energy and nutrients, which requires the rewiring of cellular metabolism. As MYC can orchestrate all aspects of cellular metabolism, its altered regulation plays a central role in these processes, such as the Warburg effect, and is a well-established hallmark of cancer development. However, our current knowledge of MYC suggests that its spatial- and concentration-dependent contribution to tumorigenesis depends more on changes in the global or relative expression of target genes. As the direct targeting of MYC is proven to be challenging due to its relatively high toxicity, understanding its underlying regulatory mechanisms is essential for the development of tumor-selective targeted therapies. The aim of this review is to comprehensively summarize the diverse forms of MYC oncogenic deregulation, including DNA-, transcriptional- and post-translational level alterations, and their consequences for cellular metabolism. Furthermore, we also review the currently available and potentially attractive therapeutic options that exploit the vulnerability arising from the metabolic rearrangement of MYC-driven tumors.

Spotlight on New Therapeutic Opportunities for MYC-Driven Cancers

MYC can be considered to be one of the most pressing and important targets for the development of novel anti-cancer therapies. This is due to its frequent dysregulation in tumors and due to the wide-ranging impact this dysregulation has on gene expression and cellular behavior. As a result, there have been numerous attempts to target MYC over the last few decades, both directly and indirectly, with mixed results. This article reviews the biology of MYC in the context of cancers and drug development. It discusses strategies aimed at targeting MYC directly, including those aimed at reducing its expression and blocking its function. In addition, the impact of MYC dysregulation on cellular biology is outlined, and how understanding this can underpin the development of approaches aimed at molecules and pathways regulated by MYC. In particular, the review focuses on the role that MYC plays in the regulation of metabolism, and the therapeutic avenues offered by inhibiting the metabolic pathways that are essential for the survival of MYC-transformed cells.

SIRT1/P53 pathway is involved in the Arsenic induced aerobic glycolysis in hepatocytes L-02 cells

Arsenic is a known human carcinogen. Low doses of arsenic can induce cell proliferation, but the mechanism remains elusive. Aerobic glycolysis, also known as the Warburg effect, is one of the characteristics of tumour cells and rapidly proliferating cells. P53 is a tumour suppressor gene that has been shown to be a negative regulator of aerobic glycolysis. SIRT1 is a deacetylase that inhibits the function of P53. In this study, we found that P53 was involved in low dose of arsenic-induced aerobic glycolysis through regulating HK2 expression in L-02 cells. Moreover, SIRT1 not only inhibited P53 expression but also decreased the acetylation level of P53-K382 in arsenic-treated L-02 cells. Meanwhile, SIRT1 influenced the expression of HK2 and LDHA, which then promoted arsenic-induced glycolysis in L-02 cells. Therefore, our study demonstrated that the SIRT1/P53 pathway is involved in arsenic-induced glycolysis, thereby promoting cell proliferation, which provides theoretical basis for enriching the mechanism of arsenic carcinogenesis.

Metabolic Rewiring and Stemness: A Critical Attribute of Pancreatic Cancer Progression

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive diseases with a poor 5-year survival rate. PDAC cells rely on various metabolic pathways to fuel their unlimited proliferation and metastasis. Reprogramming glucose, fatty acid, amino acid, and nucleic acid metabolisms contributes to PDAC cell growth. Cancer stem cells are the primary cell types that play a critical role in the progression and aggressiveness of PDAC. Emerging studies indicate that the cancer stem cells in PDAC tumors are heterogeneous and show specific metabolic dependencies. In addition, understanding specific metabolic signatures and factors that regulate these metabolic alterations in the cancer stem cells of PDAC paves the way for developing novel therapeutic strategies targeting CSCs. In this review, we discuss the current understanding of PDAC metabolism by specifically exploring the metabolic dependencies of cancer stem cells. We also review the current knowledge of targeting these metabolic factors that regulate CSC maintenance and PDAC progression.

Cellular Senescence, a Novel Area of Investigation for Metastatic Diseases

Metastasis is a systemic condition and the major challenge among cancer types, as it can lead to multiorgan vulnerability. Recently, attention has been drawn to cellular senescence, a complex stress response condition, as a factor implicated in metastatic dissemination and outgrowth. Here, we examine the current knowledge of the features required for cells to invade and colonize secondary organs and how senescent cells can contribute to this process. First, we describe the role of senescence in placentation, itself an invasive process which has been linked to higher rates of invasive cancers. Second, we describe how senescent cells can contribute to metastatic dissemination and colonization. Third, we discuss several metabolic adaptations by which senescent cells could promote cancer survival along the metastatic journey. In conclusion, we posit that targeting cellular senescence may have a potential therapeutic efficacy to limit metastasis formation.

The Role of Reprogrammed Glucose Metabolism in Cancer

Cancer cells reprogram their metabolism to meet biosynthetic needs and to adapt to various microenvironments. Accelerated glycolysis offers proliferative benefits for malignant cells by generating glycolytic products that move into branched pathways to synthesize proteins, fatty acids, nucleotides, and lipids. Notably, reprogrammed glucose metabolism and its associated events support the hallmark features of cancer such as sustained cell proliferation, hijacked apoptosis, invasion, metastasis, and angiogenesis. Overproduced enzymes involved in the committed steps of glycolysis (hexokinase, phosphofructokinase-1, and pyruvate kinase) are promising pharmacological targets for cancer therapeutics. In this review, we summarize the role of reprogrammed glucose metabolism in cancer cells and how it can be manipulated for anti-cancer strategies.

Combined Single-Cell and Spatial Transcriptomics Reveal the Metabolic Evolvement of Breast Cancer during Early Dissemination

Breast cancer is now the most frequently diagnosed malignancy, and metastasis remains the leading cause of death in breast cancer. However, little is known about the dynamic changes during the evolvement of dissemination. In this study, 65 968 cells from four patients with breast cancer and paired metastatic axillary lymph nodes are profiled using single-cell RNA sequencing (scRNA-seq) and spatial transcriptomics. A disseminated cancer cell cluster with high levels of oxidative phosphorylation (OXPHOS), including the upregulation of cytochrome C oxidase subunit 6C and dehydrogenase/reductase 2, is identified. The transition between glycolysis and OXPHOS when dissemination initiates is noticed. Furthermore, this distinct cell cluster is distributed along the tumor's leading edge. The findings here are verified in three different cohorts of breast cancer patients and an external scRNA-seq dataset, which includes eight patients with breast cancer and paired metastatic axillary lymph nodes. This work describes the dynamic metabolic evolvement of early disseminated breast cancer and reveals a switch between glycolysis and OXPHOS in breast cancer cells as the early event during lymph node metastasis.

Modulating Glycolysis to Improve Cancer Therapy

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

Target c-Myc to treat pancreatic cancer

C-Myc overexpression is a common finding in pancreatic cancer and predicts the aggressive behavior of cancer cells. It binds to the promoter of different genes, thereby regulating their transcription. C-Myc is downstream of KRAS and interacts with several oncogenic and proliferative pathways in pancreatic cancer. C-Myc enhances aerobic glycolysis in cancer cells and regulates glutamate biosynthesis from glutamine. It provides enough energy for cancer cells' metabolism and sufficient substrate for the synthesis of organic molecules. C-Myc overexpression is associated with chemoresistance, intra-tumor angiogenesis, epithelial-mesenchymal transition (EMT), and metastasis in pancreatic cancer. Despite its title, c-Myc is not "undruggable" and recent studies unveiled that it can be targeted, directly or indirectly. Small molecules that accelerate c-Myc ubiquitination and degradation have been effective in preclinical studies. Small molecules that hinder c-Myc-MAX heterodimerization or c-Myc/MAX/DNA complex formation can functionally inhibit c-Myc. In addition, c-Myc can be targeted through transcriptional, post-transcriptional, and translational modifications.

Role of LDH in tumor glycolysis: Regulation of LDHA by small molecules for cancer therapeutics

Lactate dehydrogenase (LDH) is one of the crucial enzymes in aerobic glycolysis, catalyzing the last step of glycolysis, i.e. the conversion of pyruvate to lactate. Most cancer cells are characterized by an enhanced rate of tumor glycolysis to ensure the energy demand of fast-growing cancer cells leading to increased lactate production. Excess lactate creates extracellular acidosis which facilitates invasion, angiogenesis, and metastasis and affects the immune response. Lactate shuttle and lactate symbiosis is established in cancer cells, which may further increase the poor prognosis. Several genetic and phenotypic studies established the potential role of lactate dehydrogenase A (LDHA) or LDH5, the one homo-tetramer of subunit A, in cancer development and metastasis. The LDHA is considered a viable target for drug design and discovery. Several small molecules have been discovered to date exhibiting significant LDHA inhibitory activities and anticancer activities, therefore the starvation of cancer cells by targeting tumor glycolysis through LDHA inhibition with improved selectivity can generate alternative anticancer therapeutics. This review provides an overview of the role of LDHA in metabolic reprogramming and its association with proto-oncogenes and oncogenes. This review also aims to deliver an update on significant LDHA inhibitors with anticancer properties and future direction in this area.

Tumor glycolysis, an essential sweet tooth of tumor cells

Cancer cells undergo metabolic alterations to meet the immense demand for energy, building blocks, and redox potential. Tumors show glucose-avid and lactate-secreting behavior even in the presence of oxygen, a process known as aerobic glycolysis. Glycolysis is the backbone of cancer cell metabolism, and cancer cells have evolved various mechanisms to enhance it. Glucose metabolism is intertwined with other metabolic pathways, making cancer metabolism diverse and heterogeneous, where glycolysis plays a central role. Oncogenic signaling accelerates the metabolic activities of glycolytic enzymes, mainly by enhancing their expression or by post-translational modifications. Aerobic glycolysis ferments glucose into lactate which supports tumor growth and metastasis by various mechanisms. Herein, we focused on tumor glycolysis, especially its interactions with the pentose phosphate pathway, glutamine metabolism, one-carbon metabolism, and mitochondrial oxidation. Further, we describe the role and regulation of key glycolytic enzymes in cancer. We summarize the role of lactate, an end product of glycolysis, in tumor growth, and the metabolic adaptations during metastasis. Lastly, we briefly discuss limitations and future directions to improve our understanding of glucose metabolism in cancer.

MYC and therapy resistance in cancer: risks and opportunities

The MYC transcription factor, encoded by the c-MYC proto-oncogene, is activated by growth-promoting signals, and is a key regulator of biosynthetic and metabolic pathways driving cell growth and proliferation. These same processes are deregulated in MYC-driven tumors, where they become critical for cancer cell proliferation and survival. As other oncogenic insults, overexpressed MYC induces a series of cellular stresses (metabolic, oxidative, replicative, etc.) collectively known as oncogenic stress, which impact not only on tumor progression, but also on the response to therapy, with profound, multifaceted consequences on clinical outcome. On one hand, recent evidence uncovered a widespread role for MYC in therapy resistance in multiple cancer types, with either standard chemotherapeutic or targeted regimens. Reciprocally, oncogenic MYC imparts a series of molecular and metabolic dependencies to cells, thus giving rise to cancer-specific vulnerabilities that may be exploited to obtain synthetic-lethal interactions with novel anticancer drugs. Here we will review the current knowledge on the links between MYC and therapeutic responses, and will discuss possible strategies to overcome resistance through new, targeted interventions.

The multiple roles of LDH in cancer

High serum lactate dehydrogenase (LDH) levels are typically associated with a poor prognosis in many cancer types. Even the most effective drugs, which have radically improved outcomes in patients with melanoma over the past decade, provide only marginal benefit to those with high serum LDH levels. When viewed separately from the oncological, biochemical, biological and immunological perspectives, serum LDH is often interpreted in very different ways. Oncologists usually see high serum LDH only as a robust biomarker of a poor prognosis, and biochemists are aware of the complexity of the various LDH isoforms and of their key roles in cancer metabolism, whereas LDH is typically considered to be oncogenic and/or immunosuppressive by cancer biologists and immunologists. Integrating these various viewpoints shows that the regulation of the five LDH isoforms, and their enzymatic and non-enzymatic functions is closely related to key oncological processes. In this Review, we highlight that serum LDH is far more than a simple indicator of tumour burden; it is a complex biomarker associated with the activation of several oncogenic signalling pathways as well as with the metabolic activity, invasiveness and immunogenicity of many tumours, and constitutes an extremely attractive target for cancer therapy.

Mechanism of tonifying-kidney Chinese herbal medicine in the treatment of chronic heart failure

According to traditional Chinese medicine (TCM), chronic heart failure has the basic pathological characteristics of “heart-kidney yang deficiency.” Chronic heart failure with heart- and kidney-Yang deficiency has good overlap with New York Heart Association (NYHA) classes III and IV. Traditional Chinese medicine classical prescriptions for the treatment of chronic heart failure often take “warming and tonifying kidney-Yang” as the core, supplemented by herbal compositions with functions of “promoting blood circulation and dispersing blood stasis.” Nowadays, there are still many classical and folk prescriptions for chronic heart failure treatment, such as Zhenwu decoction, Bushen Huoxue decoction, Shenfu decoction, Sini decoction, as well as Qili Qiangxin capsule. This review focuses on classical formulations and their active constituents that play a key role in preventing chronic heart failure by suppressing inflammation and modulating immune and neurohumoral factors. In addition, given that mitochondrial metabolic reprogramming has intimate relation with inflammation, cardiac hypertrophy, and fibrosis, the regulatory role of classical prescriptions and their active components in metabolic reprogramming, including glycolysis and lipid β-oxidation, is also presented. Although the exact mechanism is unknown, the classical TCM prescriptions still have good clinical effects in treating chronic heart failure. This review will provide a modern pharmacological explanation for its mechanism and offer evidence for clinical medication by combining TCM syndrome differentiation with chronic heart failure clinical stages.

Hypoxia-Related Signature Is a Prognostic Biomarker of Pancreatic Cancer

Background

Hypoxia plays a significant role in the pathogenesis of pancreatic cancer, but the effect of hypoxia-related genes in pancreatic cancer remains to be elucidated. This study aimed to identify hypoxia-related genes related to pancreatic cancer and construct a prognostic signature.

Methods

Pancreatic cancer datasets were retrieved from TCGA database. Cox regression analyses were used to identify hypoxia-related genes and construct a prognostic signature. Datasets from International Cancer Genome Consortium and GEO databases were used as validated cohorts. The CIBERSORT method was applied to estimate the fractions of immune cell types. DNA methylation and protein levels of the genes in pancreatic cancer were examined.

Results

Three hypoxia-related genes (TES, LDHA, and ANXA2) were identified as associated with patient survival and selected to construct a prognostic signature. Patients were divided into high- and low-risk groups based on the signature. Those in the high-risk group showed worse survival than those in the low-risk group. The signature was shown to be involved in the HIF-1 signaling pathway. The time-dependent ROC analyses of three independent validated cohorts further revealed that this signature had a better prognostic value in the prediction of the survival of pancreatic cancer patients. Immune cells analysis for three datasets demonstrated that high-risk signature was significantly associated with macrophages and T cells. DNA methylation and protein levels of the three genes validated their aberrant expression in pancreatic cancer.

Conclusions

Our research provided a novel and reliable prognostic signature that composes of three hypoxia-related genes to estimate the prognosis of pancreatic cancer.

Circular RNA circVAMP3 promotes aerobic glycolysis and proliferation by regulating LDHA in renal cell carcinoma

Metabolic dysfunction is seen in cancer cells where increased glycolysis provides energy for growth. Circular RNAs (circRNAs) are thought to assist in glucose metabolism and the switch to glycolysis. Through screening, we found that circVAMP3 was necessary for both glycolytic and proliferative activities in renal cell carcinoma (RCC). Furthermore, circVAMP3 expression was elevated in RCC patients in correspondence with TNM stage. Mechanistically, circVAMP3 was observed to interact directly with lactate dehydrogenase A (LDHA) and modulate its activity. The circVAMP3-LDHA interaction facilitated LDHA phosphorylation at tyrosine 10 (Y10) catalyzed by the upstream kinase fibroblast growth factor receptor type 1 (FGFR1). Therefore, this study reveals a novel molecular mechanism by which circVAMP3 promotes glycolysis and proliferation through regulating the enzymatic activity of glycolytic enzyme, suggesting that circVAMP3 may represent an RCC biomarker and treatment target.

Exploring YAP1-centered networks linking dysfunctional CFTR to epithelial-mesenchymal transition

In this work, a systems biology approach identifies potentially dysregulated EMT signaling in CF (including the Hippo, Wnt, TGF-β, p53, and MYC pathways), integrated by YAP1 and TEAD4.

Mutations in the CFTR anion channel cause cystic fibrosis (CF) and have also been related to higher cancer incidence. Previously we proposed that this is linked to an emerging role of functional CFTR in protecting against epithelial–mesenchymal transition (EMT). However, the pathways bridging dysfunctional CFTR to EMT remain elusive. Here, we applied systems biology to address this question. Our data show that YAP1 is aberrantly active in the presence of mutant CFTR, interacting with F508del, but not with wt-CFTR, and that YAP1 knockdown rescues F508del-CFTR processing and function. Subsequent analysis of YAP1 interactors and roles in cells expressing either wt- or F508del-CFTR reveal that YAP1 is an important mediator of the fibrotic/EMT processes in CF. Alongside, five main pathways emerge here as key in linking mutant CFTR to EMT, namely, (1) the Hippo pathway; (2) the Wnt pathway; (3) the TGFβ pathway; (4) the p53 pathway; and (5) MYC signaling. Several potential hub proteins which mediate the crosstalk among these pathways were also identified, appearing as potential therapeutic targets for both CF and cancer.

Jumonji-C domain-containing protein 5 suppresses proliferation and aerobic glycolysis in pancreatic cancer cells in a c-Myc-dependent manner

Despite the importance of metabolic reprogramming in cancer cells, the molecular mechanism regulating the tumor metabolic shift is still poorly understood. Deregulation of Jumonji-C domain-containing protein 5 (JMJD5) has been associated with multiple facets of biological processes in cancer cells. However, the role of JMJD5 in pancreatic cancer cells has seldom been discussed and requires further investigation. In the present study, by silencing or overexpressing JMJD5 in pancreatic cancer cells, we examined the impact of JMJD5 on cell proliferation and glucose metabolism. Using a dual luciferase assay, we assessed the effect of JMJD5 on the transcriptional activity of the c-Myc target gene. Analyzing The Cancer Genome Atlas and the Gene Expression Omnibus datasets revealed that low JMJD5 expression was associated with poor prognosis in patients with pancreatic cancer. JMJD5 loss promoted pancreatic cancer cell proliferation and induced a cellular metabolic shift from oxidative phosphorylation to glycolysis. In addition, in vivo experiments confirmed that ectopic JMJD5 expression inhibited cancer cell growth and the expression of glycolytic enzymes, such as lactate dehydrogenase and phosphoglycerate kinase 1. Moreover, JMJD5 negatively regulated c-Myc expression, the main regulator of cancer metabolism, leading to decreased c-Myc-targeted gene expression. Overall, the present study indicated that decreased JMJD5 expression promoted cell proliferation and glycolytic metabolism in pancreatic cancer cells in a c-Myc-dependent manner.

A synthesized olean-28,13β-lactam targets YTHDF1-GLS1 axis to induce ROS-dependent metabolic crisis and cell death in pancreatic adenocarcinoma

Background

Pancreatic adenocarcinoma (PAAD) is a severe malignant with a 5-year survival rate of approximately 9%. Oleanolic acid is a well-known natural triterpenoid which exhibits pharmacological activities. We previously synthesized a series of oleanolic acid derivatives and evaluated the tumor-suppressive activity of olean-28,13β-lactam (B28) in prostate cancer. However, the detailed mechanism remains to be understood.

Methods

The anti-tumor activity of B28 in PAAD was confirmed by RTCA, colony formation assay and flow cytometry. GO and KEGG enrichment analyses were performed to analyze the differentially expressed genes (DEGs) obtained by RNA sequencing. The effects of B28 on cell bioenergetics were evaluated by seahorse analyzer. Lenti-virus packaged plasmids were performed to knockdown or overexpress target genes. Alteration of mitochondrial membrane potential, ROS and GSH/GSSG were measured by corresponding detection kits according to the manufacturer's protocol.

Results

We evaluated and confirmed the promising anti-tumor activity of B28 in vitro. RNA-seq profile indicated that multiple metabolic pathways were interrupted in B28 treated PAAD cells. Next, we demonstrated that B28 induces cellular bioenergetics crisis to inhibit PAAD cells growth and induce cell death. We further validated that cell cycle arrest, inhibition of cell growth, cell apoptosis and cell bioenergetics disruption were functionally rescued by ROS scavenger NAC. Mechanistically, we found glutamine metabolism was inhibited due to B28 administration. Moreover, we validated that down-regulation of GLS1 contributes to ROS generation and bioenergetics interruption induced by B28. Furthermore, we elucidated that YTHDF1-GLS1 axis is the potential downstream target of B28 to induce PAAD cell metabolic crisis and cell death. Finally, we also confirmed the anti-tumor activity of B28 in vivo.

Conclusions

Current study demonstrates B28 disrupts YTDFH1-GLS1 axis to induce ROS-dependent cell bioenergetics crisis and cell death which finally suppress PAAD cell growth, indicating that this synthesized olean-28,13β-lactam maybe a potent agent for PAAD intervention.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-022-02562-6.

Antitumor Effects of 10058-F4 and Curcumin in Combination Therapy for Pancreatic Cancer In Vitro and In Vivo

Background

Pancreatic cancer (PC) stands out as one of the most lethal cancers. Due to late diagnosis, only a fraction of patients can be resected. Although it still has significant adverse effects and poor results, the treatment is connected with better overall survival than the prior treatment. Thus, new alternative therapy for advanced PC is needed. Materials/Methods. The impact of 10058-F4 and curcumin combination therapy on apoptosis and cell growth in SW1990 pancreatic cancer cells were determined in vitro using the CCK-8 assay and flow cytometry of Annexin V-FITC/PI, and the in vivo antitumor effect was determined utilizing SW1990-bearing pancreatic tumor mouse models induced by subcutaneous implantation.

Results

At concentrations of (10 mol/L+2 mol/L), 10058-F4+curcumin obtained the highest rate of SW1990 cell death, and they had a beneficial effect on SW1990 pancreatic tumor-bearing animals. Furthermore, c-Myc, Akt phosphorylation, and the expression of apoptosis-related molecular were reduced, and the combination therapy modified the expression of apoptosis-related molecular.

Conclusions

In vitro and in vivo, the combination of 10058-F4 plus curcumin has antipancreatic cancer actions that are substantially effective.

Glycolysis in the progression of pancreatic cancer

Metabolic reprogramming, as a key hallmark of cancers, leads to the malignant behavior of pancreatic cancer, which is closely related to tumor development and progression, as well as the supportive tumor microenvironments. Although cells produce adenosine triphosphate (ATP) from glucose by glycolysis when lacking oxygen, pancreatic cancer cells elicit metabolic conversion from oxide phosphorylation to glycolysis, which is well-known as "Warburg effect". Glycolysis is critical for cancer cells to maintain their robust biosynthesis and energy requirement, and it could promote tumor initiation, invasion, angiogenesis, and metastasis to distant organs. Multiple pathways are involved in the alternation of glycolysis for pancreatic cancer cells, including UHRF1/SIRT4 axis, PRMT5/FBW7/cMyc axis, JWA/AMPK/FOXO3a/FAK axis, KRAS/TP53/TIGAR axis, etc. These signaling pathways play an important role in glycolysis and are potential targets for the treatment of pancreatic cancer. Mutations in glycolytic enzymes (such as LDH, PKM2, and PGK1) also contribute to the early diagnosis and monitoring of pancreatic cancer. In this review, we summarized the recent advances on the mechanisms for glycolysis in pancreatic cancer and the function of glycolysis in the progression of pancreatic cancer, which suggested new targets for cancer diagnosis and treatment.

Metabolic response to radiation therapy in cancer

Tumor metabolism has emerged as a hallmark of cancer and is involved in carcinogenesis and tumor growth. Reprogramming of tumor metabolism is necessary for cancer cells to sustain high proliferation rates and enhanced demands for nutrients. Recent studies suggest that metabolic plasticity in cancer cells can decrease the efficacy of anticancer therapies by enhancing antioxidant defenses and DNA repair mechanisms. Studying radiation-induced metabolic changes will lead to a better understanding of radiation response mechanisms as well as the identification of new therapeutic targets, but there are few robust studies characterizing the metabolic changes induced by radiation therapy in cancer. In this review, we will highlight studies that provide information on the metabolic changes induced by radiation and oxidative stress in cancer cells and the associated underlying mechanisms.

Glycometabolic rearrangements-aerobic glycolysis in pancreatic ductal adenocarcinoma (PDAC): roles, regulatory networks, and therapeutic potential

INTRODUCTION

Glycometabolic rearrangements (aerobic glycolysis) is a hallmark of pancreatic ductal adenocarcinoma (PDAC) and contributes to tumorigenesis and progression through numerous mechanisms. The targeting of aerobic glycolysis is recognized as a potential therapeutic strategy which offers the possibility of improving treatment outcomes for PDAC patients.

AREAS COVERED

In this review, the role of aerobic glycolysis and its regulatory networks in PDAC are discussed. The targeting of aerobic glycolysis in PDAC is examined, and its therapeutic potential is evaluated. The relevant literature published from 2001 to 2021 was searched in databases including PubMed, Scopus, and Embase.

EXPERT OPINION

Regulatory networks of aerobic glycolysis in PDAC are based on key factors such as c-Myc, hypoxia-inducible factor 1α, the mammalian target of rapamycin pathway, and non-coding RNAs. Experimental evidence suggests that modulators or inhibitors of aerobic glycolysis promote therapeutic effects in preclinical tumor models. Nevertheless, successful clinical translation of drugs that target aerobic glycolysis in PDAC is an obstacle. Moreover, it is necessary to identify the potential targets for future interventions from regulatory networks to design efficacious and safer agents.

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

CONTEXT

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

OBJECTIVE

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

MATERIALS AND METHODS

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

RESULTS

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

DISCUSSION AND CONCLUSIONS

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

Cancer Stem Cells: Metabolic Characterization for Targeted Cancer Therapy

The subpopulation of cancer stem cells (CSCs) within tumor bulk are known for tumor recurrence and metastasis. CSCs show intrinsic resistance to conventional therapies and phenotypic plasticity within the tumor, which make these a difficult target for conventional therapies. CSCs have different metabolic phenotypes based on their needs as compared to the bulk cancer cells. CSCs show metabolic plasticity and constantly alter their metabolic state between glycolysis and oxidative metabolism (OXPHOS) to adapt to scarcity of nutrients and therapeutic stress. The metabolic characteristics of CSCs are distinct compared to non-CSCs and thus provide an opportunity to devise more effective strategies to target CSCs. Mechanism for metabolic switch in CSCs is still unravelled, however existing evidence suggests that tumor microenvironment affects the metabolic phenotype of cancer cells. Understanding CSCs metabolism may help in discovering new and effective clinical targets to prevent cancer relapse and metastasis. This review summarises the current knowledge of CSCs metabolism and highlights the potential targeted treatment strategies.

KIFC1 promotes aerobic glycolysis in endometrial cancer cells by regulating the c-myc pathway

Endometrial cancer (EC) is a common gynecological malignant tumor worldwide. It is imperative to study pathogenesis and therapeutic targets for improving the prognosis of EC. The present study aimed to explore the function and mechanism of kinesin family member C1 (KIFC1) in EC. EC tumor and adjacent normal tissues were collected from 68 pairs of patients. The expression of KIFC1 in tissues and EC cells was analyzed by immunohistochemistry, qRT-PCR or western blot. MTT assay was used to test the cell viability. Flow cytometry was used to determine apoptosis and the cell cycle. Glucose uptake, lactate production, ATP contents and lactate dehydrogenase (LDH) activity were evaluated by a glucose metabolism kit. The expression of HMGA1, c-myc and glycolytic genes was assessed using western blot or qRT-PCR. A mouse xenograft model was established in BALB/c mice to detect tumor growth in vivo. KIFC1 was significantly upregulated in EC tumor tissues compared to adjacent normal control tissues. The upregulated expression of KIFC1 was correlated with poor prognosis in patients. Lentiviral-mediated overexpression of KIFC1 observably enhanced cell viability and reduced the apoptotic rate of Ishikawa and HEC-1B cells. Cell cycle progression was also expedited in the KIFC1 vector group. Moreover, overexpression of KIFC1 elevated glucose uptake, lactate production, ATP contents and LDH activity. However, knockdown of KIFC1 by short hairpin RNA (shRNA) showed the reverse effect on cellular functions. In addition, the expression of c-myc, GLUT1, LDHA and HK2 was increased by the KIFC1 vector. Moreover, HMGA1 regulated the expression of c-myc and glycolytic genes. Upregulated HMGA1 could rescue the effect of KIFC1 knockdown on cellular functions and the expression of glycolytic genes. Finally, KIFC1 knockdown inhibits tumor growth in vivo. The upregulation of KIFC1 was correlated with poor prognosis in EC. KIFC1 promoted aerobic glycolysis in endometrial cancer cells by regulating the HMGA1/c-myc pathway. KIFC1 may be a potential target for the diagnosis and therapy of EC.

Natural products targeting cancer cell dependency

Precision cancer medicine is a tailored treatment approach for individual cancer patients with different genomic characteristics. Mutated or hyperactive oncogenes have served as main drug targets in current precision cancer medicine, while defective or inactivated tumor suppressors in general have not been considered as druggable targets. Synthetic lethality is one of very few approaches that enable to target defective tumor suppressors with pharmacological agents. Synthetic lethality exploits cancer cell dependency on a protein or pathway, which arises when the function of a tumor suppressor is defective. This approach has been proven to be effective in clinical settings since the successful clinical introduction of BRCA-PARP synthetic lethality for the treatment of breast and ovarian cancer with defective BRCA. Subsequently, large-scale screenings with RNAi, CRISPR/Cas9-sgRNAs, and chemical libraries have been applied to identify synthetic lethal partners of tumor suppressors. Natural products are an important source for the discovery of pharmacologically active small molecules. However, little effort has been made in the discovery of synthetic lethal small molecules from natural products. This review introduces recent advances in the discovery of natural products targeting cancer cell dependency and discusses potentials of natural products in the precision cancer medicine.

Novel Primary Human Cancer Stem-Like Cell Populations from Non-Small Cell Lung Cancer: Inhibition of Cell Survival by Targeting NF-κB and MYC Signaling

There is growing evidence that cancer stem cells (CSCs), a small subpopulation of self-renewal cancer cells, are responsible for tumor growth, treatment resistance, and cancer relapse and are thus of enormous clinical interest. Here, we aimed to isolate new CSC-like cells derived from human primary non-small cell lung cancer (NSCLC) specimens and to analyze the influence of different inhibitors of NF-κB and MYC signaling on cell survival. CSC-like cells were established from three squamous cell carcinomas (SCC) and three adenocarcinomas (AC) of the lung and were shown to express common CSC markers such as Prominin-1, CD44-antigen, and Nestin. Further, cells gave rise to spherical cancer organoids. Inhibition of MYC and NF-κB signaling using KJ-Pyr-9, dexamethasone, and pyrrolidinedithiocarbamate resulted in significant reductions in cell survival for SCC- and AC-derived cells. However, inhibition of the protein–protein interaction of MYC/NMYC proto-oncogenes with Myc-associated factor X (MAX) using KJ-Pyr-9 revealed the most promising survival-decreasing effects. Next to the establishment of six novel in vitro models for studying NSCLC-derived CSC-like populations, the presented investigations might provide new insights into potential novel therapies targeting NF-κB/MYC to improve clinical outcomes in NSCLC patients. Nevertheless, the full picture of downstream signaling still remains elusive.

The Glycolytic Pathway as a Target for Novel Onco-Immunology Therapies in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDA) is one of the most lethal forms of human cancer, characterized by unrestrained progression, invasiveness and treatment resistance. To date, there are limited curative options, with surgical resection as the only effective strategy, hence the urgent need to discover novel therapies. A platform of onco-immunology targets is represented by molecules that play a role in the reprogrammed cellular metabolism as one hallmark of cancer. Due to the hypoxic tumor microenvironment (TME), PDA cells display an altered glucose metabolism-resulting in its increased uptake-and a higher glycolytic rate, which leads to lactate accumulation and them acting as fuel for cancer cells. The consequent acidification of the TME results in immunosuppression, which impairs the antitumor immunity. This review analyzes the genetic background and the emerging glycolytic enzymes that are involved in tumor progression, development and metastasis, and how this represents feasible therapeutic targets to counteract PDA. In particular, as the overexpressed or mutated glycolytic enzymes stimulate both humoral and cellular immune responses, we will discuss their possible exploitation as immunological targets in anti-PDA therapeutic strategies.

The chromatin modifier MORC2 affects glucose metabolism by regulating the expression of lactate dehydrogenase A through a feed forward loop with c-Myc

Microrchidia family CW-type zinc finger 2 (MORC2) is a recently identified chromatin modifier with an emerging role in cancer metastasis. However, its role in glucose metabolism, a hallmark of malignancy, remains to be explored. We found that MORC2 is a glucose-inducible gene and a target of c-Myc. Our meta-analysis revealed that MORC2 expression is positively correlated with the expression of enzymes involved in glucose metabolism in breast cancer patients. Furthermore, overexpression of MORC2 in MCF-7 and BT-549 cells augmented the expression and activity of a key glucose metabolism enzyme, lactate dehydrogenase A (LDHA). Conversely, selective knockdown of MORC2 by siRNA markedly decreased LDHA expression and activity and in turn reduced cancer cell migration. Collectively, these findings provide evidence that MORC2, a glucose-inducible gene, modulates the migration of breast cancer cells through the MORC2-c-Myc-LDHA axis.

The metabolism of cancer cells during metastasis

Metastasis formation is the major cause of death in most patients with cancer. Despite extensive research, targeting metastatic seeding and colonization is still an unresolved challenge. Only recently, attention has been drawn to the fact that metastasizing cancer cells selectively and dynamically adapt their metabolism at every step during the metastatic cascade. Moreover, many metastases display different metabolic traits compared with the tumours from which they originate, enabling survival and growth in the new environment. Consequently, the stage-dependent metabolic traits may provide therapeutic windows for preventing or reducing metastasis, and targeting the new metabolic traits arising in established metastases may allow their eradication.

Anti-Warburg Effect of Melatonin: A Proposed Mechanism to Explain its Inhibition of Multiple Diseases

Glucose is an essential nutrient for every cell but its metabolic fate depends on cellular phenotype. Normally, the product of cytosolic glycolysis, pyruvate, is transported into mitochondria and irreversibly converted to acetyl coenzyme A by pyruvate dehydrogenase complex (PDC). In some pathological cells, however, pyruvate transport into the mitochondria is blocked due to the inhibition of PDC by pyruvate dehydrogenase kinase. This altered metabolism is referred to as aerobic glycolysis (Warburg effect) and is common in solid tumors and in other pathological cells. Switching from mitochondrial oxidative phosphorylation to aerobic glycolysis provides diseased cells with advantages because of the rapid production of ATP and the activation of pentose phosphate pathway (PPP) which provides nucleotides required for elevated cellular metabolism. Molecules, called glycolytics, inhibit aerobic glycolysis and convert cells to a healthier phenotype. Glycolytics often function by inhibiting hypoxia-inducible factor-1α leading to PDC disinhibition allowing for intramitochondrial conversion of pyruvate into acetyl coenzyme A. Melatonin is a glycolytic which converts diseased cells to the healthier phenotype. Herein we propose that melatonin's function as a glycolytic explains its actions in inhibiting a variety of diseases. Thus, the common denominator is melatonin's action in switching the metabolic phenotype of cells.

Capitalizing on Synthetic Lethality of MYC to Treat Cancer in the Digital Age

Deregulation of MYC is among the most frequent oncogenic drivers of cancer. Developing targeted therapies against MYC is, therefore, one of the most critical unmet needs of cancer therapy. Unfortunately, MYC has been labelled as undruggable due to the lack of success in developing clinically relevant MYC-targeted therapies. Synthetic lethality is a promising approach that targets MYC-dependent vulnerabilities in cancer. However, translating the synthetic lethality targets to the clinics is still challenging due to the complex nature of cancers. This review highlights the most promising mechanisms of MYC synthetic lethality and how these discoveries are currently translated into the clinic. Finally, we discuss how in silico computational platforms can improve clinical success of synthetic lethality-based therapy.

Genomic and metabolomic analysis of step-wise malignant transformation in human skin fibroblasts

Metabolic changes accompanying a step-wise malignant transformation was investigated using a syngeneic lineage of human fibroblasts. Cell immortalization was associated with minor alterations in metabolism. Consecutive loss of cell cycle inhibition in immortalized cells resulted in increased levels of oxidative phosphorylation (OXPHOS). Overexpression of the H-Ras oncoprotein produced cells forming sarcomas in athymic mice. These transformed cells exhibited increased glucose consumption, glycolysis and a further increase in OXPHOS. Because of the markedly increased OXPHOS in transformed cells, the impact of a transaminase inhibitor, aminooxyacetic acid (AOA), which decreases glutamine influx to the tricarboxylic acid (TCA) cycle, was tested. Indeed, AOA significantly decreased proliferation of malignantly transformed fibroblasts and fibrosarcoma-derived cells in vitro and in vivo. AOA also decreased proliferation of cells susceptible to malignant transformation. Metabolomic studies in normal and transformed cells indicated that, in addition to the anticipated effect on the TCA cycle, AOA decreased production of nucleotides adenosine triphosphate (ATP) and uridine monophosphate. Exogenous nucleotides partially rescued decreased proliferation of the malignant cells treated with AOA. Our data indicate that AOA blocks several metabolic pathways essential for growth of malignant cells. Therefore, OXPHOS may provide important therapeutic targets for treatment of sarcoma.

The Metabolic Heterogeneity and Flexibility of Cancer Stem Cells

Simple Summary

Cancer stem cells (CSCs) have been shown to be the main cause of therapy resistance and cancer recurrence. An analysis of their biological properties has revealed that CSCs have a particular metabolism that differs from non-CSCs to maintain their stemness properties. In this review, we analyze the flexible metabolic mechanisms of CSCs and highlight the new therapeutics that target CSC metabolism.

Abstract

Numerous findings have indicated that CSCs, which are present at a low frequency inside primary tumors, are the main cause of therapy resistance and cancer recurrence. Although various therapeutic methods targeting CSCs have been attempted for eliminating cancer cells completely, the complicated characteristics of CSCs have hampered such attempts. In analyzing the biological properties of CSCs, it was revealed that CSCs have a peculiar metabolism that is distinct from non-CSCs to maintain their stemness properties. The CSC metabolism involves not only the catabolic and anabolic pathways, but also intracellular signaling, gene expression, and redox balance. In addition, CSCs can reprogram their metabolism to flexibly respond to environmental changes. In this review, we focus on the flexible metabolic mechanisms of CSCs, and highlight the new therapeutics that target CSC metabolism.

Flavonoids against the Warburg phenotype-concepts of predictive, preventive and personalised medicine to cut the Gordian knot of cancer cell metabolism

The Warburg effect is characterised by increased glucose uptake and lactate secretion in cancer cells resulting from metabolic transformation in tumour tissue. The corresponding molecular pathways switch from oxidative phosphorylation to aerobic glycolysis, due to changes in glucose degradation mechanisms known as the 'Warburg reprogramming' of cancer cells. Key glycolytic enzymes, glucose transporters and transcription factors involved in the Warburg transformation are frequently dysregulated during carcinogenesis considered as promising diagnostic and prognostic markers as well as treatment targets. Flavonoids are molecules with pleiotropic activities. The metabolism-regulating anticancer effects of flavonoids are broadly demonstrated in preclinical studies. Flavonoids modulate key pathways involved in the Warburg phenotype including but not limited to PKM2, HK2, GLUT1 and HIF-1. The corresponding molecular mechanisms and clinical relevance of 'anti-Warburg' effects of flavonoids are discussed in this review article. The most prominent examples are provided for the potential application of targeted 'anti-Warburg' measures in cancer management. Individualised profiling and patient stratification are presented as powerful tools for implementing targeted 'anti-Warburg' measures in the context of predictive, preventive and personalised medicine.

FAM46B Promotes Apoptosis and Inhibits Glycolysis of Prostate Cancer Through Inhibition of the MYC-LDHA Axis

Objective

Increased dependence on glycolysis is a known element of cancer. This study was designed to examine critical glycolysis components including transcription factor MYC and its downstream target lactate dehydrogenase A (LDHA), potential upstream regulators of glycolysis such as family with sequence similarity 46 member B (FAM46B), and the impact of the abundance of these proteins on apoptosis and glycolysis in prostate cancer.

Materials and Methods

A total of 70 primary prostate cancer patient samples were compared to normal tissues for FAM46B and LDHA expression and the corresponding patients’ survival was monitored for 60 months. Prostate cancer cell lines were employed for protein expression manipulation, glucose uptake and LDH assays, and apoptosis measurements. A xenograft mouse model was used to quantify the role of FAM46B and LDHA on tumor growth in vivo.

Results

FAM46B expression was reduced in prostate tumor tissue compared to normal tissue and prostate cancer patients who expressed low amounts of FAM46B had shortened average lifespans compared to those who expressed higher amounts of FAM46B (p=0.008). FAM46B overexpression reduced glucose uptake, decreased LDH activity, and induced apoptosis in prostate cancer cell lines while FAM46B shRNA increased MYC levels in a non-malignant prostate cell line (P69). Conversely, forced expression of LDHA in LNCaP cells produced an increase in glycolysis markers with a corresponding decrease in apoptosis. FAM46B-overexpressing xenografts had starkly blunted growth which was restored with co-overexpression of LDHA.

Conclusion

FAM46B plays a central role in regulating glycolysis and apoptosis in prostate cancer and operates through the regulation of LDHA via MYC. FAM46B’s keystone status in prostate cancer makes it a potential, robust biomarker for prostate cancer prognosis and a promising therapeutic target.

Glutathione S-Transferase Mu-3 Predicts a Better Prognosis and Inhibits Malignant Behavior and Glycolysis in Pancreatic Cancer

Background: Pancreatic cancer (PC) is a lethal malignancy with an extremely unfavorable 5-year survival rate and a high mortality rate. Glutathione S-transferase mu-3 (GSTM3) has been shown to exert different functions in the progression and development of various cancers, except for PC. This study aimed to explore the role of GSTM3 in the malignant behavior and metabolic aspects of PC, its clinical significance, and its possible molecular mechanism in pancreatic cancer.

Methods: Tumor microarrays of pancreatic ductal adenocarcinoma (PDAC) were used to evaluate the clinicopathological variables and GSTM3 expression by immunohistochemical staining. Kaplan–Meier survival and Cox regression analyses were further performed to assess the prognosis. The effect of GSTM3 on PC aggressiveness was detected using overexpressing and silencing transfection methods. Western blot, RT-qPCR, CCK-8, and cell cycle assay were applied to evaluate the expression level and proliferation. A xenograft animal model was assessed. Reactive oxygen species (ROS) were measured using the laser confocal scanner and glycolysis was detected using an Agilent Seahorse kit. RNA sequencing was used to assess the underlying mechanism and the signaling pathway involved.

Results: GSTM3 was relatively poorly expressed in PDAC tissues compared to para-tumoral tissues and a high level of GSTM3 indicated good overall survival. Functionally, overexpression of GSTM3 could significantly inhibit cell proliferation by delaying the G0/G1 transition, whereas the opposite results were found in the GSTM3 downregulation group. In addition, xenograft animal models further confirmed the effect on proliferation. Moreover, silencing of GSTM3 induced ROS accumulation and promoted glycolysis in PC, indicating its tumor suppressive effect, and vice versa when GSTM3 was upregulated. Finally, RNA sequencing results demonstrated that GSTM3 facilitates anti-tumorigenicity partly via the JAK-STAT signaling pathway in PC.

Conclusion: GSTM3 inhibited tumor progression and altered the metabolic pattern in PC. This may be a potential predictive biomarker in PC and a prospective therapeutic target.

Targeting lactate dehydrogenase A (LDHA) exerts antileukemic effects on T-cell acute lymphoblastic leukemia

Background

T‐cell acute lymphoblastic leukemia (T‐ALL) is an uncommon and aggressive subtype of acute lymphoblastic leukemia (ALL). In the serum of T‐ALL patients, the activity of lactate dehydrogenase A (LDHA) is increased. We proposed that targeting LDHA may be a potential strategy to improve T‐ALL outcomes. The current study was conducted to investigate the antileukemic effect of LDHA gene‐targeting treatment on T‐ALL and the underlying molecular mechanism.

Methods

Primary T‐ALL cell lines Jurkat and DU528 were treated with the LDH inhibitor oxamate. MTT, colony formation, apoptosis, and cell cycle assays were performed to investigate the effects of oxamate on T‐ALL cells. Quantitative real‐time PCR (qPCR) and Western blotting analyses were applied to determine the related signaling pathways. A mitochondrial reactive oxygen species (ROS) assay was performed to evaluate ROS production after T‐ALL cells were treated with oxamate. A T‐ALL transgenic zebrafish model with LDHA gene knockdown was established using CRISPR/Cas9 gene‐editing technology, and then TUNEL, Western blotting, and T‐ALL tumor progression analyses were conducted to investigate the effects of LDHA gene knockdown on T‐ALL transgenic zebrafish.

Results

Oxamate significantly inhibited proliferation and induced apoptosis of Jurkat and DU528 cells. It also arrested Jurkat and DU528 cells in G0/G1 phase and stimulated ROS production (all P < 0.001). Blocking LDHA significantly decreased the gene and protein expression of c‐Myc, as well as the levels of phosphorylated serine/threonine kinase (AKT) and glycogen synthase kinase 3 beta (GSK‐3β) in the phosphatidylinositol 3′‐kinase (PI3K) signaling pathway. LDHA gene knockdown delayed disease progression and down‐regulated c‐Myc mRNA and protein expression in T‐ALL transgenic zebrafish.

Conclusion

Targeting LDHA exerted an antileukemic effect on T‐ALL, representing a potential strategy for T‐ALL treatment.

Fine-tuning the metabolic rewiring and adaptation of translational machinery during an epithelial-mesenchymal transition in breast cancer cells

ABSTRACT

BACKGROUND

During breast cancer progression, the epithelial to mesenchymal transition has been associated with metastasis and endocrine therapy resistance; however, the underlying mechanisms remain elusive. To gain insight into this process, we studied the transition undergone by MCF7-derived cells, which is driven by the constitutive nuclear expression of a MKL1 variant devoid of the actin-binding domain (MKL1 ΔN200). We characterized the adaptive changes that occur during the MKL1-induced cellular model and focused on regulation of translation machinery and metabolic adaptation.

METHODS

We performed a genome-wide analysis at the transcriptional and translational level using ribosome profiling complemented with RNA-Seq and analyzed the expression of components of the translation machinery and enzymes involved in energy metabolism. NGS data were correlated with metabolomic measurements and quantification of specific mRNAs extracted from polysomes and western blots.

RESULTS

Our results reveal the expression profiles of a luminal to basal-like state in accordance with an epithelial to mesenchymal transition. During the transition, the synthesis of ribosomal proteins and that of many translational factors was upregulated. This overexpression of the translational machinery appears to be regulated at the translational level. Our results indicate an increase of ribosome biogenesis and translation activity. We detected an extensive metabolic rewiring occurring in an already "Warburg-like" context, in which enzyme isoform switches and metabolic shunts indicate a crucial role of HIF-1α along with other master regulatory factors. Furthermore, we detected a decrease in the expression of enzymes involved in ribonucleotide synthesis from the pentose phosphate pathway. During this transition, cells increase in size, downregulate genes associated with proliferation, and strongly upregulate expression of cytoskeletal and extracellular matrix genes.

CONCLUSIONS

Our study reveals multiple regulatory events associated with metabolic and translational machinery adaptation during an epithelial mesenchymal-like transition process. During this major cellular transition, cells achieve a new homeostatic state ensuring their survival. This work shows that ribosome profiling complemented with RNA-Seq is a powerful approach to unveil in-depth global adaptive cellular responses and the interconnection among regulatory circuits, which will be helpful for identification of new therapeutic targets.

A Driver Never Works Alone-Interplay Networks of Mutant p53, MYC, RAS, and Other Universal Oncogenic Drivers in Human Cancer

The knowledge accumulating on the occurrence and mechanisms of the activation of oncogenes in human neoplasia necessitates an increasingly detailed understanding of their systemic interactions. None of the known oncogenic drivers work in isolation from the other oncogenic pathways. The cooperation between these pathways is an indispensable element of a multistep carcinogenesis, which apart from inactivation of tumor suppressors, always includes the activation of two or more proto-oncogenes. In this review we focus on representative examples of the interaction of major oncogenic drivers with one another. The drivers are selected according to the following criteria: (1) the highest frequency of known activation in human neoplasia (by mutations or otherwise), (2) activation in a wide range of neoplasia types (universality) and (3) as a part of a distinguishable pathway, (4) being a known cause of phenotypic addiction of neoplastic cells and thus a promising therapeutic target. Each of these universal oncogenic factors—mutant p53, KRAS and CMYC proteins, telomerase ribonucleoprotein, proteasome machinery, HSP molecular chaperones, NF-κB and WNT pathways, AP-1 and YAP/TAZ transcription factors and non-coding RNAs—has a vast network of molecular interrelations and common partners. Understanding this network allows for the hunt for novel therapeutic targets and protocols to counteract drug resistance in a clinical neoplasia treatment.

Silencing c-Myc Enhances the Antitumor Activity of Bufalin by Suppressing the HIF-1α/SDF-1/CXCR4 Pathway in Pancreatic Cancer Cells

Background

Pancreatic cancer is one of the most aggressive malignancies. Bufalin, a traditional Chinese medicine, has been used to treat pancreatic cancer as an antitumor agent although the mechanism by which it exerts its effects is still unclear. c-Myc has been found to be overexpressed in more than half of human cancers including pancreatic cancer. However, the role of c-Myc in pancreatic cancer cells and its influence in bufalin-treated pancreatic cancer are yet to be clarified. The present study aimed to investigate the role of c-Myc in the antitumor activity of bufalin in pancreatic cancer.

Methods

c-Myc siRNA and overexpression plasmid were transfected into pancreatic cancer cells to construct the cell models. c-Myc expression was detected via quantitative real-time polymerase chain reaction and western blot. The effect of c-Myc on bufalin-induced inhibition of cell proliferation was detected via CCK-8 assay. Cell apoptosis and the cell cycle were analyzed via flow cytometry. Cell invasion and migration was detected via Transwell and wound healing assays, respectively. In addition, the effect of bufalin on the suppression of tumor growth in vivo was studied in nude mice model subcutaneously injected with PANC-1 and SW1990 cells. Hematoxylin-eosin and terminal deoxynucleotidyl transferase dUTP nick-end labeling assay were used to evaluate pathological changes in vivo. The expression of HIF-1α/SDF-1/CXCR4 were detected via western blot.

Results

CCK-8 assay showed that bufalin could inhibit the proliferation of pancreatic cancer cell, and c-Myc downregulation enhanced this effect. Similarly, c-Myc downregulation enhanced the effect of bufalin on cell cycle arrest, apoptosis, and the invasion and migration of pancreatic cancer cell in vitro. Further mechanism assay showed that c-Myc enhances the effect by regulating the HIF-1α/SDF-1/CXCR4 signaling pathway. The in vivo studies verified the results that c-Myc enhances the effect of bufalin through regulation of the HIF-1α/SDF-1/CXCR4 pathway.

Conclusions

Downregulation of c-Myc enhanced the antitumor activity of bufalin in pancreatic cancer cells by suppressing the HIF-1α/SDF-1/CXCR4 pathway. These findings indicate that c-Myc inhibitors could enhance the clinical therapeutic effect of bufalin and may expand the clinical application of bufalin accordingly.