Mechanisms, impacts and therapeutic strategies of glucose metabolic reprogramming in tumours

Reprogramming of glucose metabolism: The hallmark of malignant transformation and target for advanced diagnostics and treatments

As epigenetic regulators, long non-coding RNAs (lncRNAs) are involved in various important regulatory processes and typically interact with RNA-binding proteins (RBPs) to exert their core functional effects. An increasing number of studies have demonstrated that lncRNAs can regulate the occurrence and development of cancer through a variety of complex mechanisms and can also participate in tumor glucose metabolism by directly or indirectly regulating the Warburg effect. As one of the metabolic characteristics of tumor cells, the Warburg effect provides a large amount of energy and numerous intermediate products to meet the consumption demands of tumor metabolism, providing advantages for the occurrence and development of tumors. The present review article summarizes the regulatory effects of lncRNAs on the reprogramming of glucose metabolism after interacting with RBPs in tumors. The findings discussed herein may aid in the better understanding of the pathogenesis of malignancies, and may provide novel therapeutic targets, as well as new diagnostic and prognostic markers for human cancers.

Pulmonary arterial hypertension (PAH) is a chronic and fatal disease characterized by pulmonary vascular remodeling, similar to the 'Warburg effect' observed in cancer, which is caused by reprogramming of glucose metabolism. Oroxylin A (OA), an active compound derived from Scutellaria baicalensis, which can inhibit glycolytic enzymes [hexokinase 2 (HK2), Lactate dehydrogenase (LDH), and pyruvate dehydrogenase kinase 1 (PDK1) by downregulating aerobic glycolysis to achieve the treatment of liver cancer. To the best of our knowledge, however, the impact of OA on PAH has not been addressed. Consequently, the present study aimed to evaluate the potential protective role and mechanism of OA against PAH induced by monocrotaline (MCT; 55 mg/kg). The mean pulmonary artery pressure (mPAP) was measured using the central venous catheter method; HE and Masson staining were used to observe pulmonary artery remodeling. Non‑targeted metabolomics was used to analyze the metabolic pathways and pathway metabolites in MCT‑PAH rats. Western Blot analysis was employed to assess the levels of glucose transporter 1 (Glut1), HK2), pyruvate kinase (PK), isocitrate dehydrogenase 2 (IDH2), pyruvate dehydrogenase kinase 1(PDK1), and lactate dehydrogenase (LDH) protein expression in both lung tissue samples from MCT‑PAH rats. The results demonstrated that intragastric administration of OA (40 and 80 mg/kg) significantly decreased mPAP from 43.61±1.88 mmHg in PAH model rats to 26.51±1.53 mmHg and relieve pulmonary artery remodeling. Untargeted metabolomic analysis and multivariate analysis indicated abnormal glucose metabolic pattern in PAH model rats, consistent with the Warburg effect. OA administration decreased this effect on the abnormal glucose metabolism. The protein levels of key enzymes involved in glucose metabolism were evaluated by western blotting, which demonstrated that OA could improve aerobic glycolysis and inhibit PAH by decreasing the protein levels of Glut1, HK2, LDH, PDK1 and increasing the protein levels of PK and IDH2. In conclusion, OA decreased MCT‑induced PAH in rats by reducing the Warburg effect.

ABSTRACTBackgroundColorectal cancer (CRC) is one of the most common malignant tumors, and its morbidity ranks third among all cancers, with a trend toward younger patients. Metabolic reprogramming, a unique metabolic mode in tumor cells, is closely related to the occurrence and development of CRC. Numerous studies have confirmed that many genetic and protein changes can regulate cellular metabolic reprogramming, of which changes in glucose metabolism have the greatest impact. These aberrant metabolic processes provide energy and essential nutrients to CRC cells, promoting their proliferation and metastasis and influencing tumor resistance. The purpose of this review is to outline the role of glucose metabolic reprogramming in the onset and development of CRC, discuss the research progress in the dual reprogramming of glucose metabolism and lipid metabolism or glucose metabolism and amino acid metabolism, and address the issues of targeted metabolism therapy and drug resistance.MethodsWe searched PubMed for review articles published in English between January 1, 2015, and April 26, 2024, which included “Colorectal Neoplasms” with “Metabolic Reprogramming” OR “Glucose Metabolism Disorders” OR “The Warburg Effect” OR “Targeted Therapy.” Subsequently, the literature was classified, organized, and summarized. Various types of studies were integrated and compiled into this review. Additionally, mechanism diagrams were drawn to facilitate the understanding of this study. The figures were created using BioRender.com and has obtained the official publication license.ConclusionsGlucose metabolic reprogramming serves as a pivotal driver of CRC initiation, progression, and chemoresistance, while its crosstalk with lipid or amino acid metabolic reprogramming further amplifies the malignant phenotype of CRC. Targeted therapeutic strategies aiming at glucose metabolic reprogramming (such as metabolic inhibitors, combination with immunotherapy) and related clinical research have demonstrated potential for inhibiting CRC progression and improving treatment outcomes.

Malignant cells undergo a metabolic transformation to satisfy the demands of growth and proliferation. This metabolic reprogramming has been considered as an emerging hallmark of cancer. It is well established that most normal cells get energy first via glycolysis in the cytosol that is followed by mitochondrial oxidative phosphorylation (OXPHO) under aerobic conditions but when oxygen is scarce, glycolysis rather than OXPHO for energy supply. However, cancer cells prefer to perform glycolysis in the cytosol even in the presence of oxygen, a phenomenon first observed by Otto Warburg and now famously known as ‘’Warburg effect’’ or ‘’aerobic glycolysis’’. Such reprogramming of glucose metabolism has been validated within many tumors, and increased glycolysis facilitates biosynthesis of biomass (e.g., nucleotides, amino acids and lipids) by providing glycolytic intermediates as raw material. Besides the dysregulation of glucose metabolism, metabolic reprogramming in cancer cells has been characterized by aberrant lipid metabolism, amino acids metabolism, mitochondrial biogenesis, and other bioenergetics metabolic pathways. However, the two noticeable characteristics of tumor cell metabolism are the Warburg effect and glutaminolysis, which, respectively, demonstrate the dependence of tumor cells on glucose and glutamine. Investigation on these metabolic changes would uncover fundamental molecular events of malignancy and help to find better ways to diagnose and treat cancer. This review aimed at appraising recent findings related to the drivers of glucose and glutamine metabolism reprogramming, their crosstalk in cancer cells, and their potential in cancer therapy.

Estrogen and estrogen receptor (ER) play a fundamental role in breast cancer. To support the rapid proliferation of ER+ breast cancer cells, estrogen increases glucose uptake and reprograms glucose metabolism. Meanwhile, estrogen/ER activates the anticipatory unfolded protein response (UPR) preparing cancer cells for the increased protein production required for subsequent cell proliferation. Here, we report that thioredoxin-interacting protein (TXNIP) is an important regulator of glucose metabolism in ER+ breast cancer cells, and estrogen/ER increases glucose uptake and reprograms glucose metabolism via activating anticipatory UPR and subsequently repressing TXNIP expression. In 2 widely used ER+ breast cancer cell lines, MCF7 and T47D, we showed that MCF7 cells express high TXNIP levels and exhibit mitochondrial oxidative phosphorylation (OXPHOS) phenotype, while T47D cells express low TXNIP levels and display aerobic glycolysis (Warburg effect) phenotype. Knockdown of TXNIP promoted glucose uptake and Warburg effect, while forced overexpression of TXNIP inhibited glucose uptake and Warburg effect. We further showed that estrogen represses TXNIP expression and activates UPR sensor inositol-requiring enzyme 1 (IRE1) via ER in the breast cancer cells, and IRE1 activity is required for estrogen suppression of TXNIP expression and estrogen-induced cell proliferation. Our study suggests that TXNIP is involved in estrogen-induced glucose uptake and metabolic reprogramming in ER+ breast cancer cells and links anticipatory UPR to estrogen reprogramming glucose metabolism.

Most mammalian cells use glucose as a main fuel source. Glucose is metabolized via glycolysis to pyruvate, which enters the mitochondria and then generates ATP through Krebs cycle in normal condition. However, metabolism is characteristically reprogrammed and cancer cells or highly proliferative cells preferably generate ATP through lactate production by lactate dehydrogenase (LDH/LDHA), referred to as the Warburg effect or metabolic reprogramming toward aerobic glycolysis. Efficient control of energy metabolism is the key to maintaining metabolic homeostasis, and disturbance in energy balance provokes diseases such as obesity, diabetes and cancer. However, the mechanisms underlying efficient energy metabolic homeostasis and breast cancer development are poorly understood. HJC0152, a novel small molecule glucose metabolism modulator, was developed using structure- and fragment-based drug design strategies and molecular modeling techniques. Aggressively growing and metastatic breast cancer cells of triple-negative subtype (MDA-MB-231) treated with HJC0152 showed decreased activity and protein level of LDHA, which resulted in a decrease lactate production. In addition, these cells also exhibited decreased glucose uptake and HK2 protein level. Furthermore, the amount of intracellular ATP in MDA-MB-231 cells was significantly reduced. Our findings suggest that HJC0152 is capable of reprogramming caner metabolism by modulating glucose metabolism and ATP production. These results may provide a rationale to develop HJC0152 as an effective therapeutic for cancer and other metabolic diseases with aberrant glucose metabolism. In addition, HJC0152 can serve as a molecular probing tool for elucidating the key factors responsible for developing breast cancer and other metabolic diseases.This work was supported by Grants P50 CA097007, and P30DA028821 (JZ) from the NIH, CPRIT (JZ), John Sealy Memorial Endowment Fund (JZ), DFI Grants from MD Anderson Cancer Center (QS), Holden Family Research Grant in BC Prevention (QS), and NCI PREVENT Program HHSN26100002 (QS). Citation Format: Kim H, Dong J, Xu J, Li D, Zheng Z, Ye N, Zhang Z, Chen H, Zhou J, Shen Q. Reprogramming glucose metabolism and energy production in breast cancer cells [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-02-08.

Most mammalian cells use glucose as the primary fuel source. Glucose is metabolized via glycolysis to pyruvate, which is further transferred into mitochondria for generation of ATP through the Krebs cycle in normal condition. However, metabolism is characteristically reprogrammed and cancer cells or highly proliferative cells preferably generate ATP through lactate production by lactate dehydrogenase (LDH/LDHA), referred to as the Warburg effect or metabolic reprogramming toward anaerobic glycolysis. Efficient control of energy metabolism is the key to maintaining metabolic homeostasis, and disturbance in energy balance provokes diseases such as obesity, diabetes and cancer. However, the mechanisms underlying efficient energy metabolic homeostasis and breast cancer development are poorly understood. HJC0152, a novel small-molecule glucose metabolism modulator, was developed using structure-/fragment-based drug design strategies and molecular modeling techniques. Aggressively growing and metastatic breast cancer cells of triple-negative subtype (MDA-MB-231) treated with HJC0152 showed inhibited cell growth. Intriguingly, HJC0152 decreased activity and protein level of LDHA, which resulted in a decrease of lactate production in breast cancer cells. In addition, these cells also exhibited a decrease of glucose uptake by reducing Glut1 and HK2 protein level and modulation of the expression of glycolytic enzymes. Furthermore, HJC0152 treatment causes decreased mitochondrial membrane energy potential, resulting in significantly reduced level of intracellular ATP in MDA-MB-231 cells. Our findings suggest that HJC0152 is capable of reprogramming caner metabolism by modulating glucose metabolism and ATP production. These results may provide a rationale to develop HJC0152 as an effective therapeutics for cancer and other metabolic diseases with aberrant glucose metabolism. In addition, HJC0152 can serve as a molecular probing tool for elucidating the key factors responsible for developing breast cancer and other metabolic diseases. Citation Format: Hyejin Kim, Jiabin Dong, Jimin Xu, Dengfeng Li, Zhi Zheng, Na Ye, Ziwei Zhang, Haiying Chen, Jia Zhou, Qiang Shen. Suppression of breast cancer by reprogramming glucose metabolism and energy production with HJC0152 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4883.

Novel insight into the Warburg effect: Sweet temptation.

The reprogramming of glucose metabolism from oxidative to glycolytic metabolism, known as the Warburg effect, is an anomalous characteristic of cancer cell metabolism. Recent studies have revealed a subset of microRNAs (miRNAs) that play critical roles in regulating the reprogramming of glucose metabolism in cancer cells. These miRNAs regulate cellular glucose metabolism by directly targeting multiple metabolic genes, including those encoding key glycolytic enzymes. In the first part of this review, we summarized the recent knowledge of miRNA regulation in the reprogramming of glucose metabolism in cancer cells and discussed the potential utilization of the key miRNA regulators as metabolic targets for developing new antitumor agents. Then, we summarized recent advances in methods and techniques for studying miRNA regulation in cancer cell metabolism.

Clinical studies have shown similar rapid improvements in body mass and glycemic control after Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG). Evidence suggests that adaptive intestinal tissue growth and reprogramming of intestinal glucose disposal play a key role in the beneficial effects on glucose homeostasis after RYGB, but it is not known whether such adaptive changes also occur after sleeve gastrectomy. High-fat diet-induced obese rats were subjected to either VSG or RYGB, and intestinal growth and functional adaptations were assessed by using morphometric, immunohistochemical, and immuno-blot techniques, 3 months after surgery or sham surgery. The cross-sectional areas of the Roux and common limbs are significantly increased after RYGB compared with sham surgery (Roux limb: 17.1 ± 4.0 vs. 5.5 ± 0.1 mm(2); common limb: 11.7 ± 0.6 vs. 5.1 ± 0.5 mm(2); p < 0.01), but the cross-sectional area of the corresponding jejunum is not different from controls after VSG. Similarly, mucosal thickness and the number of GLP-1 cells are not increased after VSG. Protein expression of hexokinase II is increased fourfold (p < 0.01) in the Roux limb after RYGB, but not in the jejunum after VSG. Adaptive hypertrophy and reprogramming of glucose metabolism in the small intestine are not necessary for VSG to improve body composition and glycemic control. The similar beneficial effects of VSG and RYGB on glucose homeostasis might be mediated by different mechanisms.

Aberrant glucose metabolism characterized by high levels of glycolysis, even in the presence of oxygen, is an important hallmark of cancer. This metabolic reprogramming referred to as the Warburg effect is essential to the survival of tumor cells and provides them with substrates required for biomass generation. Molecular mechanisms responsible for this shift in glucose metabolism remain elusive. As described herein, we found that aberrant expression of the proinflammatory protein transglutaminase 2 (TG2) is an important regulator of the Warburg effect in mammary epithelial cells. Mechanistically, TG2 regulated metabolic reprogramming by constitutively activating nuclear factor (NF)-κB, which binds to the hypoxia-inducible factor (HIF)-1α promoter and induces its expression even under normoxic conditions. TG2/NF-κB-induced increase in HIF-1α expression was associated with increased glucose uptake, increased lactate production and decreased oxygen consumption by mitochondria. Experimental suppression of TG2 attenuated HIF-1α expression and reversed downstream events in mammary epithelial cells. Moreover, downregulation of p65/RelA or HIF-1α expression in these cells restored normal glucose uptake, lactate production, mitochondrial respiration and glycolytic protein expression. Our results suggest that aberrant expression of TG2 is a master regulator of metabolic reprogramming and facilitates metabolic alterations in epithelial cells even under normoxic conditions. A TG2-induced shift in glucose metabolism helps breast cancer cells to survive under stressful conditions and promotes their metastatic competence.

Role of glucose metabolic reprogramming in colorectal cancer progression and drug resistance

Glucose metabolic reprogramming from oxidative to aerobic glycolysis, referred as the Warburg effect, is a hallmark of tumor cells. Accumulating evidence suggests that a subset of microRNAs play pivotal roles in modulating such reprogramming of glucose metabolism in cancer cells. miR-3662 has been implicated previously in both pro-tumorigenic and anti-tumorigenic effects in several types of cancer. The expression level of miR-3662 is downregulated in acute myeloid leukemia, whereas increased miR-3662 expression is observed in lung adenocarcinoma. However, the roles and underlying mechanisms of miR-3662 in hepatocellular carcinoma (HCC) metabolic reprogramming remain unclear. Our present study revealed that miR-3662 was frequently downregulated in HCC tissues and cell lines. The low expression level of miR-3662 was associated with tumor size, tumor multiplicity, Edmondson grade, and tumor-node-metastasis stage. Gain-of-function and loss-of-function assays showed that miR-3662 dampened glycolysis by reducing lactate production, glucose consumption, cellular glucose-6-phosphate level, ATP generation, and extracellular acidification rate, and increasing oxygen consumption rate in HCC cells after treatment with the hypoxia mimetic CoCl2. Moreover, miR-3662 suppressed cell growth in vitro and in vivo, and induced G1/S cell cycle arrest. miR-3662 inhibited the activation of ERK and JNK signaling pathways in HCC. By combined computational and experimental approaches, hypoxia-inducible factor-1α (HIF-1α) was determined as a direct target of miR-3662. After treatment with the hypoxia mimetic CoCl2, miR-3662 regulated the Warburg effect and HCC progression via decreasing HIF-1α expression. Our findings uncover a mechanistic role for miR-3662/HIF-1α axis in HCC metabolic reprogramming, providing a potential therapeutic strategy in liver cancer.

Currently there are no targeted therapeutic strategies for estrogen receptor (ER)-negative breast cancer (ENBC), which constitutes 30-40% of breast cancer cases and is prone to metastasize and recur. Distant metastasis accounts for 90% of cancer-associated deaths. The majority of deaths from breast cancer are caused by distant metastasis developed in lung, liver, bone, or brain. However, to date it remains a challenge and unmet need to treat existing metastasis and block new metastasis in cancer patients. Dysregulated glucose and energy metabolism is critically involved in the development and progression of various cancers via promoting aberrant cell growth, malignant transformation and metastasis, but the potential role of glucose/energy metabolism in ENBC progression and metastasis has scarcely been explored heretofore, thus representing a key knowledge gap and a potential avenue for anticancer targeting. A number of anticancer metabolic and biogenetic therapies have been developed, yet none of them has progressed to clinical use, due to their limited potency, specificity or drug properties such as toxicity and poor bioavailability. We recently identified a novel small molecule HJC0152 that significantly suppresses ENBC xenograft tumor growth and blocks ER-negative mammary tumor development in mouse models. HJC0152 treatment for 24-72 hours differentially modulates protein expression of HK1, PFK-L, PFKFB2, ENO2, PDH, PDK1, PGAM1 and ALDOA in a time-dependent manner. HJC0152 also regulates the transcription of genes involved in glucose and mitochondrial energy metabolism, including the subunits of mitochondrial respiratory chain complexes. Functional assessments of mitochondrial complexes demonstrate that HJC0152 significantly inhibits Complexes IV but increases Complex V (ATP synthase) function, while Complexes I and II function is minimally affected. Migration and invasion of MDA-MB-231 cells are significantly inhibited by HJC0152 treatment. In vivo, HJC0152 administrated either before, concurrent with or after tail vein injection of MDA-MB-231 cells dramatically blocks the development of lung macro- and micro-metastasis in all groups. These results suggest that HJC0152 can specifically reprogram/restore the dysregulated glucose metabolism by inducing specific glycolytic enzyme expression and mitochondrial respiratory chain function, likely via targeting one or more upstream signal molecule(s) that regulates glucose and energy metabolism, thereby suppressing breast cancer progression to metastasis. This work was supported by Grants P50 CA097007, P30DA028821, and R21MH093844 (J.Z.) from the NIH, CPRIT (J.Z.), John Sealy Memorial Endowment Fund (J.Z.), DFI Seed Grants from MD Anderson Cancer Center (Q.S.), and Holden Family Research Grant in Breast Cancer Prevention from the Prevent Cancer Foundation (Q.S). Citation Format: Hao Zou, Na Ye, Hui Pang, Dan Zhang, Ruping Yan, Haijun Chen, Guoshuai Cai, Lili Wang, Zhengduo Yang, Haiying Chen, Grace Xu, Yingchao Zhang, Ritu Arora, Ming Tan, Yongchang Wei, Jia Zhou, Qiang Shen. Reprogramming glucose metabolism and energy production with a small molecule HJC0152 suppresses breast cancer development and progression to metastasis. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 329.