Crucial players in glycolysis: Cancer progress

Circular RNA 0006349 Augments Glycolysis and Malignance of Non-small Cell Lung Cancer Cells Through the microRNA-98/MKP1 Axis

Background: The involvement of dysregulated circular RNAs (circRNAs) in human diseases has been increasingly recognized. In this study, we focused on the function of a newly screened circRNA, circ_0006349, in the progression of non-small-cell lung cancer (NSCLC) and the molecules of action.

Methods: The NSCLC circRNA dataset GSE101684, microRNA (miRNA) dataset GSE29250, and mRNA dataset GSE51852 obtained from the GEO database were used to identify the differentially expressed genes in NSCLC samples. Tumor and normal tissues were collected from 59 patients with NSCLC. The expression of circ_0006349, miR-98, and MAP kinase phosphatase 1 (MKP1) in collected tissue samples and in acquired cells was determined. The binding relationships between miR-98 and circ_0006349/MKP1 were predicted and validated. Altered expression of circ_0006349, miR-98, and MKP1 was introduced in NSCLC cells to examine their roles in cell growth, apoptosis, and glycolysis.

Results: Circ_0006349 and MKP1 were upregulated, and miR-98 was poorly expressed in the collected tumor tissues and the acquired NSCLC cell lines. Circ_0006349 was identified as a sponge for miR-98 to elevate MKP1 expression. Silencing of circ_0006349 suppressed proliferation and increased apoptosis of Calu-3 and H1299 cells, and it reduced glycolysis, glucose uptake, and the production of lactate in cells. Upon circ_0006349 knockdown, further downregulation of miR-98 or upregulation of MKP1 restored the malignant behaviors of cells.

Conclusion: This research demonstrated that circ_0006349 derepressed MKP1 expression by absorbing miR-98, which augmented the proliferation and glycolysis of NSCLC cells and promoted cancer development.

Antitumor Effect of Morusin via G1 Arrest and Antiglycolysis by AMPK Activation in Hepatocellular Cancer

Though Morusin isolated from the root of Morus alba was known to have antioxidant, anti-inflammatory, antiangiogenic, antimigratory, and apoptotic effects, the underlying antitumor effect of Morusin is not fully understood on the glycolysis of liver cancers. Hence, in the current study, the antitumor mechanism of Morusin was explored in Hep3B and Huh7 hepatocellular carcninomas (HCC) in association with glycolysis and G1 arrest. Herein, Morusin significantly reduced the viability and the number of colonies in Hep3B and Huh7 cells. Moreover, Morusin significantly increased G1 arrest, attenuated the expression of cyclin D1, cyclin D3, cyclin E, cyclin-dependent kinase 2 (CDK2), cyclin-dependent kinase 4 (CDK4), and cyclin-dependent kinase 6 (CDK6) and upregulated p21 and p27 in Hep3B and Huh7 cells. Interestingly, Morusin significantly activated phosphorylation of the adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK)/acetyl-CoA carboxylase (ACC) but attenuated the expression of the p-mammalian target of protein kinase B (AKT), rapamycin (mTOR), c-Myc, hexokinase 2(HK2), pyruvate kinases type M2 (PKM2), and lactate dehydrogenase (LDH) in Hep3B and Huh7 cells. Consistently, Morusin suppressed lactate, glucose, and adenosine triphosphate (ATP) in Hep3B and Huh7 cells. Conversely, the AMPK inhibitor compound C reduced the ability of Morusin to activate AMPK and attenuate the expression of p-mTOR, HK2, PKM2, and LDH-A and suppressed G1 arrest induced by Morusin in Hep3B cells. Overall, these findings suggest that Morusin exerts an antitumor effect in HCCs via AMPK mediated G1 arrest and antiglycolysis as a potent dietary anticancer candidate.

Circ-PGC increases the expression of FOXR2 by targeting miR-532-3p to promote the development of non-small cell lung cancer

This study was to explore the function of circular progastricsin (circ-PGC) in NSCLC. The histological morphology of tumor tissues was observed by hematoxylin and eosin (HE) staining. The expression of circ-PGC, miR-532-3p and forkhead box R2 (FOXR2) mRNA was measured by real-time quantitative polymerase chain reaction (RT-qPCR). The protein level of FOXR2 was checked by western blot. In functional analyses, cell viability, colony formation, cell apoptosis, cell migration and cell invasion were investigated using cell counting kit-8 (CCK-8) assay, colony formation assay, flow cytometry assay, wound healing assay and transwell assay. Besides, glycolysis metabolism was assessed by the levels of glucose consumption, lactate production and adenosine triphosphate (ATP) production. The predicted relationship between miR-532-3p and circ-PGC and FOXR2 was verified by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. The results showed that circ-PGC and FOXR2 were upregulated in NSCLC tissues and cells. Circ-PGC knockdown or FOXR2 knockdown inhibited NSCLC cell viability, colony formation, cell migration, invasion and glycolysis metabolism, and FOXR2 overexpression rescued these inhibitory effects caused by circ-PGC knockdown. MiR-532-3p harbored the same binding site with circ-PGC and FOXR2, and circ-PGC positively regulated FOXR2 expression by targeting miR-532-3p. The expression of β-catenin and c-Myc was decreased in cells after circ-PGC knockdown but recovered with miR-532-3p inhibition or FOXR2 overexpression. Circ-PGC downregulation also inhibited tumor growth in vivo. In conclusion, circ-PGC positively regulated FOXR2 expression by competitively binding to miR-532-3p, thereby promoting the development of NSCLC, and the Wnt/β-catenin signaling pathway might be activated by the circ-PGC/miR-532-3p/FOXR2 network.

Silencing of circ_0000517 suppresses proliferation, glycolysis, and glutamine decomposition of non-small cell lung cancer by modulating miR-330-5p/YY1 signal pathway

In recent years, circular RNA (circRNA) has been found to be involved in a variety of cancer processes. More and more attention has been paid to the research of circRNA in lung cancer. This study aims to investigate whether circ_0000517 affected the physiology of non-small cell lung cancer (NSCLC) and the underlying mechanism. The results demonstrated that circ_0000517 was highly expressed in lung cancer tissues and cells, and overexpression of circ_0000517 was negatively correlated with the prognosis of NSCLC patients. Silencing of circ_0000517 significantly inhibited the proliferation, glycolysis, and glutamine decomposition of NSCLC cells in vitro and repressed the growth of xenografted tumors in vivo. Moreover, knockdown of circ_0000517 attenuated the expression of PCNA, HK2, LDHA, ASCT2, and GLS1. Further study found that circ_0000517 targeted miR-330-5p and miR-330-5p targeted YY1. In addition, miR-330-5p inhibitor reversed inhibition of cancer cell proliferation, glycolysis, and glutamine decomposition induced by si-circ_0000517. In conclusion, our study revealed that silencing of circ_0000517 improved the progression of NSCLC through regulating miR-330-5p/YY1 axis.

Influences of the lncRNA TUG1-miRNA-34a-5p network on fibroblast-like synoviocytes (FLSs) dysfunction in rheumatoid arthritis through targeting the lactate dehydrogenase A (LDHA)

Background

Rheumatoid arthritis (RA) is a systemic and chronic inflammatory disease. The cellular glucose metabolism of fibroblast‐like synoviocytes (FLSs) of RA has been revealed to be essential to the pathogenesis and development of RA. To date, the precise roles and molecular mechanisms of long noncoding RNA TUG1 in RA have not been elucidated.

Methods

TUG1 and miR‐34a‐5p were detected by qRT‐PCR. Interactions between lncRNA‐miRNA and miRNA‐mRNA were validated by RNA pull‐down assay and luciferase assay. The glucose metabolism was evaluated by glucose uptake and extracellular acidification rate (ECAR). Cell viability was determined by MTT assay and Annexin V assay.

Results

TUG1 expression was significantly upregulated in synovial fibroblast‐like synoviocytes (FLSs) compared with normal FLSs. Functional assays uncovered that silence of TUG1 suppressed FLSs‐RA invasion, migration, glucose metabolism, and increased apoptosis. Bioinformatics analysis indicated that TUG1 interacted with miR‐34a‐5p. RNA pull‐down assay and luciferase assay validated that TUG1 sponged miR‐34a‐5p in FLSs‐RA. Overexpression of miR‐34a‐5p effectively inhibited glucose metabolism of FLSs‐RA. Furthermore, the glucose metabolism of FLSs‐RA was significantly elevated compared with normal FLSs. The glucose metabolism enzyme, LDHA, was directly targeted by miR‐34a‐5p in FLSs. Rescue experiments validated that the miR‐34a‐5p‐inhibited glucose metabolism of FLSs‐RA was through targeting LDHA. Finally, we showed restoration of miR‐34a‐5p in TUG1‐overexpressing FLSs‐RA successfully overcame the TUG1‐promoted glucose metabolism and apoptosis resistance via targeting LDHA.

Conclusion

The present study uncovered critical roles and molecular mechanisms underlying the TUG1‐mediated glucose metabolism and apoptosis of FLSs‐RA through modulating the miR‐34a‐5p‐LDHA pathway in fibroblast‐like synoviocytes of rheumatoid arthritis.

Glycolysis- and immune-related novel prognostic biomarkers of Ewing's sarcoma: glucuronic acid epimerase and triosephosphate isomerase 1

INTRODUCTION

Owing to the poor prognosis of Ewing's sarcoma, reliable prognostic biomarkers are highly warranted for clinical diagnosis of the disease.

MATERIALS AND METHODS

A combination of the weighted correlation network analysis and differentially expression analysis was used for initial screening; glycolysis-related genes were extracted and subjected to univariate Cox, LASSO regression, and multivariate Cox analyses to construct prognostic models. The immune cell composition of each sample was analysed using CIBERSORT software. Immunohistochemical analysis was performed for assessing the differential expression of modelled genes in Ewing's sarcoma and paraneoplastic tissues.

RESULTS

A logistic regression model constructed for the prognosis of Ewing's sarcoma exhibited that the patient survival rate in the high-risk group is much lower than in the low-risk group. CIBERSORT analysis exhibited a strong correlation of Ewing's sarcoma with naïve B cells, CD8⁺ T cells, activated NK cells, and M0 macrophages (P < 0.05). Immunohistochemical analysis confirmed the study findings.

CONCLUSIONS

GLCE and TPI1 can be used as prognostic biomarkers to predict the prognosis of Ewing's sarcoma, and a close association of Ewing's sarcoma with naïve B cells, CD8⁺ T cells, activated NK cells, and M0 macrophages provides a novel approach to the disease immunotherapy.

Identification and validation of a novel glycolysis-related gene signature for predicting the prognosis in ovarian cancer

Background

Ovarian cancer (OC) is the most lethal gynaecological tumor. Changes in glycolysis have been proven to play an important role in OC progression. We aimed to identify a novel glycolysis-related gene signature to better predict the prognosis of patients with OC.

Methods

mRNA and clinical data were obtained from The Cancer Genome Atlas (TCGA), International Cancer Genome Consortium (ICGC) and Genotype Tissue Expression (GTEx) database. The “limma” R package was used to identify glycolysis-related differentially expressed genes (DEGs). Then, a multivariate Cox proportional regression model and survival analysis were used to develop a glycolysis-related gene signature. Furthermore, the TCGA training set was divided into two internal test sets for validation, while the ICGC dataset was used as an external test set. A nomogram was constructed in the training set, and the relative proportions of 22 types of tumor-infiltrating immune cells were evaluated using the “CIBERSORT” R package. The enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were determined by single-sample gene set enrichment analysis (ssGSEA) with the “GSVA” R package. Finally, the expression and function of the unreported signature genes ISG20 and SEH1L were explored using immunohistochemistry, western blotting, qRT-PCR, proliferation, migration, invasion and xenograft tumor assays.

Results

A five-gene signature comprising ANGPTL4, PYGB, ISG20, SEH1L and IRS2 was constructed. This signature could predict prognosis independent of clinical factors. A nomogram incorporating the signature and three clinical features was constructed, and the calibration plot suggested that the nomogram could accurately predict the survival rate. According to ssGSEA, the signature was associated with KEGG pathways related to axon guidance, mTOR signalling, tight junctions, etc. The proportions of tumor-infiltrating immune cells differed significantly between the high-risk group and the low-risk group. The expression levels of ISG20 and SEH1L were lower in tumor tissues than in normal tissues. Overexpression of ISG20 or SEH1L suppressed the proliferation, migration and invasion of Caov3 cells in vitro and the growth of xenograft tumors in vivo.

Conclusion

Five glycolysis-related genes were identified and incorporated into a novel risk signature that can effectively assess the prognosis and guide the treatment of OC patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02045-0.

Novel circular RNA circSLIT2 facilitates the aerobic glycolysis of pancreatic ductal adenocarcinoma via miR-510-5p/c-Myc/LDHA axis

Increasing evidence has indicated the great diagnostic and therapeutic potentials of circular RNAs (circRNAs) in human cancers. Although the biological roles of circRNAs in pancreatic ductal adenocarcinoma (PDAC) have been partially annotated, the potential regulatory mechanism of circRNAs in PDAC tumorigenesis remains poorly understood. Here, our study found that the novel circRNA circSLIT2 was significantly upregulated in PDAC tissues and cells. Clinically, ectopic high-expression of circSLIT2 was correlated with unfavorable prognosis of PDAC patients. Functional experiments demonstrated that circSLIT2 promoted the aerobic glycolysis and proliferation of PDAC cells in vitro, and circSLIT2 knockdown inhibited tumor growth in vivo. Mechanistically, circSLIT2 acted as miRNA sponge to target miR-510-5p/c-Myc axis. Furthermore, c-Myc bound with the promoter region of lactate dehydrogenase A (LDHA) to activate the transcription. Collectively, present findings reveal that circSLIT2/miR-510-5p/c-Myc/LDHA axis participates in the aerobic glycolysis and carcinogenesis of PDAC, and may act as a promising therapeutic target.

A Prognostic Model for Brain Glioma Patients Based on 9 Signature Glycolytic Genes

Objective

To screen glycolytic genes linked to the glioma prognosis and construct the prognostic model.

Methods

The relevant data of glioma were downloaded from TCGA and GTEx databases. GSEA of glycolysis-related pathways was carried out, and enriched differential genes were extracted. Screening out prognostic-related genes with conspicuous significance and construction of the prognostic model were conducted by multivariate Cox regression analysis and Lasso regression analysis. The model was evaluated, and cBioPortal was used to analyze the mutation of the model gene. The expression of the model gene in tumor and normal colon tissue was analyzed. The model was used to evaluate the prognosis of patients in different groups to verify the applicability of the model.

Results

339 differentially glycolytic-related genes were enriched in REACTOME_GLYCOLYSIS, GLYCOLYTIC_PROCESS, HALLMARK_GLYCOLYSIS, and other pathways. We obtained 9 key prognostic genes and constructed the prognostic evaluation model. The 3-year AUC values of the ROC curve display model are greater than 0.75, which indicates that the accuracy of the model is good. The relation of age and risk score to prognosis is shown by univariate and multivariate Cox analysis. The expression of SRD5A3, MDH2, and B3GAT3 genes was significantly upregulated in the tumor tissues, while the HDAC4 and G6PC2 genes were downregulated. The mutation rate of MDH2 and HDAC4 genes was the highest. This model could effectively distinguish the risk of poor prognosis of patients in any age stage.

Conclusion

The prognostic assessment models based on glycolysis-related nine-gene signature could accurately predict the prognosis of patients with GBM.

A glycolysis-based three-gene signature predicts survival in patients with lung squamous cell carcinoma

BACKGROUND

Lung cancer is one of the most lethal and most prevalent malignant tumors worldwide, and lung squamous cell carcinoma (LUSC) is one of the major histological subtypes. Although numerous biomarkers have been found to be associated with prognosis in LUSC, the prediction effect of a single gene biomarker is insufficient, especially for glycolysis-related genes. Therefore, we aimed to develop a novel glycolysis-related gene signature to predict survival in patients with LUSC.

METHODS

The mRNA expression files and LUSC clinical information were obtained from The Cancer Genome Atlas (TCGA) dataset.

RESULTS

Based on Gene Set Enrichment Analysis (GSEA), we found 5 glycolysis-related gene sets that were significantly enriched in LUSC tissues. Univariate and multivariate Cox proportional regression models were performed to choose prognostic-related gene signatures. Based on a Cox proportional regression model, a risk score for a three-gene signature (HKDC1, ALDH7A1, and MDH1) was established to divide patients into high-risk and low-risk subgroups. Multivariate Cox regression analysis indicated that the risk score for this three-gene signature can be used as an independent prognostic indicator in LUSC. Additionally, based on the cBioPortal database, the rate of genomic alterations in the HKDC1, ALDH7A1, and MDH1 genes were 1.9, 1.1, and 5% in LUSC patients, respectively.

CONCLUSION

A glycolysis-based three-gene signature could serve as a novel biomarker in predicting the prognosis of patients with LUSC and it also provides additional gene targets that can be used to cure LUSC patients.

Mechanisms of Metabolic Reprogramming in Cancer Cells Supporting Enhanced Growth and Proliferation

Cancer cells alter metabolic processes to sustain their characteristic uncontrolled growth and proliferation. These metabolic alterations include (1) a shift from oxidative phosphorylation to aerobic glycolysis to support the increased need for ATP, (2) increased glutaminolysis for NADPH regeneration, (3) altered flux through the pentose phosphate pathway and the tricarboxylic acid cycle for macromolecule generation, (4) increased lipid uptake, lipogenesis, and cholesterol synthesis, (5) upregulation of one-carbon metabolism for the production of ATP, NADH/NADPH, nucleotides, and glutathione, (6) altered amino acid metabolism, (7) metabolism-based regulation of apoptosis, and (8) the utilization of alternative substrates, such as lactate and acetate. Altered metabolic flux in cancer is controlled by tumor-host cell interactions, key oncogenes, tumor suppressors, and other regulatory molecules, including non-coding RNAs. Changes to metabolic pathways in cancer are dynamic, exhibit plasticity, and are often dependent on the type of tumor and the tumor microenvironment, leading in a shift of thought from the Warburg Effect and the “reverse Warburg Effect” to metabolic plasticity. Understanding the complex nature of altered flux through these multiple pathways in cancer cells can support the development of new therapies.

Elevated TEFM expression promotes growth and metastasis through activation of ROS/ERK signaling in hepatocellular carcinoma

TEFM (transcription elongation factor of mitochondria) has been identified as a novel nuclear-encoded transcription elongation factor in the transcription of mitochondrial genome. Our bioinformatics analysis of TCGA data revealed an aberrant over-expression of TEFM in hepatocellular carcinoma (HCC). We analyzed its biological effects and clinical significance in this malignancy. TEFM expression was analyzed by quantitative real-time PCR, western blot, and immunohistochemistry analysis in HCC tissues and cell lines. The effects of TEFM on HCC cell growth and metastasis were determined by cell proliferation, colony formation, flow cytometric cell cycle and apoptosis, migration, and invasion assays. TEFM expression was significantly increased in HCC tissues mainly caused by down-regulation of miR-194-5p. Its increased expression is correlated with poor prognosis of HCC patients. TEFM promoted HCC growth and metastasis both in vitro and in vivo by promoting G1–S cell transition, epithelial-to-mesenchymal transition (EMT), and suppressing cell apoptosis. Mechanistically, TEFM exerts its tumor growth and metastasis promoting effects at least partly through increasing ROS production and subsequently by activation of ERK signaling. Our study suggests that TEFM functions as a vital oncogene in promoting growth and metastasis in HCC and may contribute to the targeted therapy of HCC.

Effects of the Novel PFKFB3 Inhibitor KAN0438757 on Colorectal Cancer Cells and Its Systemic Toxicity Evaluation In Vivo

BACKGROUND

Despite substantial progress made in the last decades in colorectal cancer (CRC) research, new treatment approaches are still needed to improve patients' long-term survival. To date, the promising strategy to target tumor angiogenesis metabolically together with a sensitization of CRC to chemo- and/or radiotherapy by PFKFB3 (6-phosphofructo-2-kinase/fructose-2,6-biphosphatase-3) inhibition has never been tested. Therefore, initial evaluation and validation of newly developed compounds such as KAN0438757 and their effects on CRC cells are crucial steps preceding to in vivo preclinical studies, which in turn may consolidate new therapeutic targets.

MATERIALS AND METHODS

The efficiency of KAN0438757 to block PFKFB3 expression and translation in human CRC cells was evaluated by immunoblotting and real-time PCR. Functional in vitro assays assessed the effects of KAN0438757 on cell viability, proliferation, survival, adhesion, migration and invasion. Additionally, we evaluated the effects of KAN0438757 on matched patient-derived normal and tumor organoids and its systemic toxicity in vivo in C57BL6/N mice.

RESULTS

High PFKFB3 expression is correlated with a worse survival in CRC patients. KAN0438757 reduces PFKFB3 protein expression without affecting its transcriptional regulation. Additionally, a concentration-dependent anti-proliferative effect was observed. The migration and invasion capacity of cancer cells were significantly reduced, independent of the anti-proliferative effect. When treating colonic patient-derived organoids with KAN0438757 an impressive effect on tumor organoids growth was apparent, surprisingly sparing normal colonic organoids. No high-grade toxicity was observed in vivo.

CONCLUSION

The PFKFB3 inhibitor KAN0438757 significantly reduced CRC cell migration, invasion and survival. Moreover, on patient-derived cancer organoids KAN0438757 showed significant effects on growth, without being overly toxic in normal colon organoids and healthy mice. Our findings strongly encourage further translational studies to evaluate KAN0438757 in CRC therapy.

Glycolysis-Related Genes Serve as Potential Prognostic Biomarkers in Clear Cell Renal Cell Carcinoma

Metabolic rearrangement is a marker of cancer that has been widely studied in recent years. One of the major metabolic characteristics of tumor cells is the high levels of glycolysis, even under aerobic conditions, a phenomenon that is called the "Warburg effect." We investigated the expression and copy number variation (CNV) frequency of all glycolysis-related genes in multiple cancer types and found many differentially expressed genes, particularly in clear cell renal cell carcinoma (ccRCC). Single nucleotide variants (SNVs) showed that the overall average mutation frequency for all genes was low. The purpose of this study was to establish a predictive model by studying glycolysis-related genes in ccRCC. We compared the expression of glycolysis-related genes in 539 ccRCC tissues and 72 normal renal tissues from The Cancer Genome Atlas dataset and identified 17 upregulated and 26 downregulated genes. Pathway analysis revealed that PSAT1 and SDHB could activate the cell cycle, RPIA could activate the DNA damage response, and HK3 could activate apoptosis and EMT signaling, while PDK2 could inhibit apoptosis. The results of the drug sensitivity analysis suggested that some of these differentially expressed genes were positively correlated with drug sensitivity. Thirteen genes were selected from the gene coexpression network and the LASSO regression analysis. The Kaplan-Meier overall survival curves showed that the expression of upregulated genes in ccRCC patients was associated with lower overall survival. We established a predictive model consisting of 13 genes (RPIA, G6PD, PSAT1, ENO2, HK3, IDH1, PDK4, PGM2, PGK1, FBP1, OGDH, SUCLA2, and SUCLG2). This predictive model correlated well with the development and progression of ccRCC. Thus, it is of great value in the diagnosis and prognostic evaluation of ccRCC and may aid the identification of potential prognostic biomarkers and drug targets.

Diethyldithiocarbamate-copper complex (CuET) inhibits colorectal cancer progression via miR-16-5p and 15b-5p/ALDH1A3/PKM2 axis-mediated aerobic glycolysis pathway

Exploring novel anticancer drugs to optimize the efficacy may provide a benefit for the treatment of colorectal cancer (CRC). Disulfiram (DSF), as an antialcoholism drug, is metabolized into diethyldithiocarbamate-copper complex (CuET) in vivo, which has been reported to exert the anticancer effects on various tumors in preclinical studies. However, little is known about whether CuET plays an anti-cancer role in CRC. In this study, we found that CuET had a marked effect on suppressing CRC progression both in vitro and in vivo by reducing glucose metabolism. Mechanistically, using RNA-seq analysis, we identified ALDH1A3 as a target gene of CuET, which promoted cell viability and the capacity of clonal formation and inhibited apoptosis in CRC cells. MicroRNA (miR)-16-5p and 15b-5p were shown to synergistically regulate ALDH1A3, which was negatively correlated with both of them and inversely correlated with the survival of CRC patients. Notably, using co-immunoprecipitation followed with mass spectrometry assays, we identified PKM2 as a direct downstream effector of ALDH1A3 that stabilized PKM2 by reducing ubiquitination. Taken together, we disclose that CuET treatment plays an active role in inhibiting CRC progression via miR-16-5p and 15b-5p/ALDH1A3/PKM2 axis-mediated aerobic glycolysis pathway.

miR-218 inhibits glucose metabolism in non-small cell lung cancer via the NF-κB signaling pathway

High glucose metabolism is recognized as one of the hallmarks of cancer and increased expression levels of several key factors involved in glucose metabolism have been reported in non-small cell lung cancer (NSCLC). Previous studies showed that microRNA (miR)-218 is reduced in NSCLC, but its function in glucose metabolism in NSCLC is not fully understood. The present study aimed to investigate the effect of miR-218 on glucose metabolism in NSCLC cell lines and the underlying molecular mechanism. The present results suggested that miR-218 reduced glucose consumption, the mechanism of glycolysis and activity in the pentose phosphate pathway. In addition, glucose transporter 1 (GLUT1) was identified to be a direct target of miR-218, while overexpression of GLUT1 did not abolish the effect of miR-218 on glucose metabolism. The present results indicated that phosphorylation of NF-κB p65 was significantly decreased by miR-218 in NSCLC cells and that activation of NF-κB led to the inhibition of miR-218 regulation of glucose metabolism. In conclusion, the present results suggested that miR-218 downregulated glucose metabolism in NSCLC not only by directly targeting GLUT1, but also via the NF-κB signaling pathway.

Domesticated and optimized mitochondria: Mitochondrial modifications based on energetic status and cellular stress

Mitochondria are the main source of energy and play an important role in coupling intracellular and intercellular metabolic cooperation. Cellular stress and energetic status can affect various mitochondrial behaviors, including mitochondrial biogenesis, mitophagy, assembly of respiratory chain supercomplexes and mitochondrial distribution. These modifications usually result in adaptive adjustment of mitochondrial output and resistance to cellular stress. However, when the pro-death signals triggered by excessive damage converge to mitochondria, mitochondrial reserve and functional status can profoundly determine the direction of cell death, and even affect the survival and death of surrounding or distant tissues. In this review, we discuss multiple mitochondrial modifications in eukaryotes based on metabolic status and cellular stress, and review the emerging knowledge about the effects of mitochondrial dysfunction on the fate of cells and surrounding tissues.

Prognostic model of invasive ductal carcinoma of the breast based on differentially expressed glycolysis-related genes

Background

Invasive ductal carcinoma (IDC) is a common pathological type of breast cancer that is characterized by high malignancy and rapid progression. Upregulation of glycolysis is a hallmark of tumor growth, and correlates with the progression of breast cancer. We aimed to establish a model to predict the prognosis of patients with breast IDC based on differentially expressed glycolysis-related genes (DEGRGs).

Methods

Transcriptome data and clinical data of patients with breast IDC were from The Cancer Genome Atlas (TCGA). Glycolysis-related gene sets and pathways were from the Molecular Signatures Database (MSigDB). DEGRGs were identified by comparison of tumor tissues and adjacent normal tissues. Univariate Cox regression and least absolute shrinkage and selection operator (LASSO) regression were used to screen for DEGRGs with prognostic value. A risk-scoring model based on DEGRGs related to prognosis was constructed. Receiver operating characteristic (ROC) analysis and calculation of the area under the curve (AUC) were used to evaluate the performance of the model. The model was verified in different clinical subgroups using an external dataset (GSE131769). A nomogram that included clinical indicators and risk scores was established. Gene function enrichment analysis was performed, and a protein-protein interaction network was developed.

Results

We analyzed data from 772 tumors and 88 adjacent normal tissues from the TCGA database and identified 286 glycolysis-related genes from the MSigDB. There were 185 DEGRGs. Univariate Cox regression and LASSO regression indicated that 13 of these genes were related to prognosis. A risk-scoring model based on these 13 DEGRGs allowed classification of patients as high-risk or low-risk according to median score. The duration of overall survival (OS) was longer in the low-risk group (P < 0.001), and the AUC was 0.755 for 3-year OS and 0.726 for 5-year OS. The results were similar when using the GEO data set for external validation (AUC for 3-year OS: 0.731, AUC for 5-year OS: 0.728). Subgroup analysis showed there were significant differences in OS among high-risk and low-risk patients in different subgroups (T1-2, T3-4, N0, N1-3, M0, TNBC, non-TNBC; all P < 0.01). The C-index was 0.824, and the AUC was 0.842 for 3-year OS and 0.808 for 5-year OS from the nomogram. Functional enrichment analysis demonstrated the DEGRGs were mainly involved in regulating biological functions.

Conclusions

Our prognostic model, based on 13 DEGRGs, had excellent performance in predicting the survival of patients with IDC of the breast. These DEGRGs appear to have important biological functions in the progression of this cancer.

Thrombospondin 2/Toll-Like Receptor 4 Axis Contributes to HIF-1α-Derived Glycolysis in Colorectal Cancer

Background

Aerobic glycolysis is a typical metabolic reprogramming in tumor cells, which contributes to the survival and proliferation of tumor cells. The underlying mechanisms controlling this metabolic switch in colorectal cancer (CRC), however, remain only partially understood.

Methods

The Cancer Genome Atlas (TCGA) dataset and Gene Expression Omnibus (GEO) (GDS4382, GSE6988, GSE35834) were used to analyzed the mRNA expression of THBS2. 392 paired samples of CRC and adjacent non-cancerous tissues were collected to detect the expression of THBS2 by IHC. The correlation of THBS2 expression with categorical clinical variables in patients with CRC was evaluated using chi-square analysis or Student's t-test. CCK-8, colony formation, and animal CT scan were used to functional analysis of THBS2 in CRC.

Results

Thrombospondin 2 (THBS2) is aberrantly upregulated and linked to a poor prognosis in CRC. Subsequent experiments also showed that THBS2 promotes the proliferation of CRC cells. In terms of mechanism, THBS2 interacted with Toll-like receptor 4 (TLR4), but not with the other toll-like receptors (TLRs), which upregulated the mRNA expression of GLUT1, HK2, ALDOA, PKM2, and LDHA and enhanced glycolytic capacity in CRC cells. Moreover, THBS2/TLR4 axis significantly increased the protein level of HIF-1α and blocking HIF-1α by siRNA reversed the enhanced glycolytic capacity and the upregulated expression of glycolytic enzymes in CRC cells.

Conclusion

Our findings revealed that the THBS2/TLR4 axis contributes to HIF-1α derived glycolysis and eventually promotes CRC progress.

Circular RNA circSEMA5A promotes bladder cancer progression by upregulating ENO1 and SEMA5A expression

Bladder cancer (BC) is one of the most commonly diagnosed urologic carcinomas, with high recurrence and death rates. Circular RNAs (circRNAs) are a class of noncoding RNAs which are anomalously expressed in cancers and involved in the progression of cancers. In this study, we found that circSEMA5A was upregulated in BC tissues and cell lines. The overexpressed circSEMA5A was correlated with malignant characteristics of BC. In vitro data indicated that circSEMA5A promoted proliferation, suppressed apoptosis, facilitated migration, accelerated invasion, enhanced angiogenesis and promotes glycolysis of BC. Mechanistically, circSEMA5A served as a miRNA sponge for miR-330-5p to upregulates Enolase 1 (ENO1) expression and facilitated the activation of Akt and β-catenin signaling pathways. Then, we showed that circSEMA5A exerted its biological functions partially via miR-330-5p/ENO1 signaling. Moreover, circSEMA5A raised SEMA5A expression by recruiting EIF4A3 to enhance the mRNA stability of SEMA5A, and thereby accelerated BC angiogenesis. To sum up, circSEMA5A is upregulated in BC and facilitates BC progression by mediating miR-330-5p/ENO1 signaling and upregulating SEMA5A expression.

Identification of circ_0085616 as an Upregulated and Oncogenic Circular RNA in Cervical Cancer Via the miR-503-5p-Mediated ATXN7L3 Activation

Background: Increasing evidence enhanced the recognition of circular RNAs (circRNAs) implicated in cancer progression. CircRNA_0085616 (circ_0085616) is a novel circRNA with high expression in cervical cancer (CC); its function and action mechanism are explored during this study. Methods: The measurement of circ_0085616, microRNA-503-5p (miR-503-5p), and Ataxin-7L3 (ATXN7L3) was performed via quantitative real-time polymerase chain reaction. Next, 3-(4,5-dimethylthiazol-2-y1)-2, 5-diphenyl tetrazolium bromide (MTT) and colony formation assays were implemented to analyze the proliferative ability. Cell metastasis was evaluated by using transwell migration and invasion assays. Glycolysis was analyzed by using glucose consumption, lactate and adenosine triphosphate production. Western blot was employed for protein analysis. The target binding was performed by dual-luciferase reporter assay and RNA immunoprecipitation assay. An animal experiment in vivo was conducted by xenografts. Results: Circ_0085616 was heightened and its downregulation blocked cellular proliferation, metastasis, and glycolysis in CC. Then, we found that circ_0085616 had a sponge effect on miR-503-5p and the miR-503-5p inhibitor could ameliorate the effects of circ_0085616 knockdown on CC cells. In addition, miR-503-5p directly targeted ATXN7L3 to obstruct CC cell proliferation, metastasis, and glycolytic process. Further, circ_0085616 could enhance ATXN7L3 by sequestering miR-503-5p, and the miR-503-5p/ATXN7L3 axis was also responsible for circ_0085616 on promoting CC tumorigenesis in vivo. Conclusion: It was obvious that circ_0085616 facilitated the carcinogenic effect on CC via the activation of ATXN7L3 by sponging miR-503-5p. Our study may be likely to provide a novel molecular target for CC therapy.

Puerarin Inhibits the Progression of Bladder Cancer by Regulating circ_0020394/miR-328-3p/NRBP1 Axis

Background: Previous studies have shown puerarin to be a potential therapeutic drug for treatment of bladder cancer. But the role and possible molecular mechanism of puerarin remain unknown. Methods: Cell viability, apoptosis, migration, and invasion were assessed by Cell Counting Kit-8 (CCK-8), flow cytometry, and transwell assays, respectively. Western blot was used to measure the levels of all protein. Glucose consumption and lactate production were detected using a glucose and lactate assay kit. Circular RNA_0020394 (circ_0020394), microRNA-328-3p (miR-328-3p), and nuclear receptor binding protein 1 (NRBP1) levels were measured by quantitative real-time polymerase chain reaction (qRT-PCR). The interaction between miRNA and circRNA or mRNA was confirmed using dual-luciferase reporter assay. In vivo experiments were performed to examine the effect of puerarin on tumor growth. Results: Puerarin suppressed cell viability, migration, invasion, and glycolysis, and induced apoptosis in bladder cancer. circ_0020394 was downregulated in puerarin-treated bladder cancer cells, and circ_0020394 overexpression attenuated the inhibitory effect of puerarin on cell progression. Moreover, circ_0020394 could bind to miR-328-3p, and miR-328-3p directly targeted NRBP1. Functionally, miR-328-3p could reverse the promotion effect of circ_0020394 overexpression on the progression of puerarin-treated cells, and silencing NRBP1 counteracted the effects of anti-miR-328-3p on puerarin-treated cells. Mechanically, circ_0020394 could increase NRBP1 expression by acting as miR-328-3p sponge in puerarin-treated bladder cancer cells. Besides, puerarin inhibited tumorigenesis in vivo by increasing miR-328-3p and decreasing the levels of circ_0020394 and NRBP1. Conclusions: Puerarin impedes cell viability, migration, invasion, and glycolysis, and promoted apoptosis in bladder cancer by regulating circ_0020394/miR-328-3p/NRBP1 axis.

Metastasis of Uveal Melanoma with Monosomy-3 Is Associated with a Less Glycogenetic Gene Expression Profile and the Dysregulation of Glycogen Storage

The prolonged storage of glucose as glycogen can promote the quiescence of tumor cells, whereas the accumulation of an aberrant form of glycogen without the primer protein glycogenin can induce the metabolic switch towards a glycolytic phenotype. Here, we analyzed the expression of n = 67 genes involved in glycogen metabolism on the uveal melanoma (UM) cohort of the Cancer Genome Atlas (TCGA) study and validated the differentially expressed genes in an independent cohort. We also evaluated the glycogen levels with regard to the prognostic factors via a differential periodic acid-Schiff (PAS) staining. UMs with monosomy-3 exhibited a less glycogenetic and more insulin-resistant gene expression profile, together with the reduction of glycogen levels, which were associated with the metastases. Expression of glycogenin-1 (Locus: 3q24) was lower in the monosomy-3 tumors, whereas the complementary isoform glycogenin-2 (Locus: Xp22.33) was upregulated in females. Remarkably, glycogen was more abundant in the monosomy-3 tumors of male versus female patients. We therefore provide the first evidence to the dysregulation of glycogen metabolism as a novel factor that may be aggravating the course of UM particularly in males.

Insights into the New Cancer Therapy through Redox Homeostasis and Metabolic Shifts

Modest levels of reactive oxygen species (ROS) are necessary for intracellular signaling, cell division, and enzyme activation. These ROS are later eliminated by the body’s antioxidant defense system. High amounts of ROS cause carcinogenesis by altering the signaling pathways associated with metabolism, proliferation, metastasis, and cell survival. Cancer cells exhibit enhanced ATP production and high ROS levels, which allow them to maintain elevated proliferation through metabolic reprograming. In order to prevent further ROS generation, cancer cells rely on more glycolysis to produce ATP and on the pentose phosphate pathway to provide NADPH. Pro-oxidant therapy can induce more ROS generation beyond the physiologic thresholds in cancer cells. Alternatively, antioxidant therapy can protect normal cells by activating cell survival signaling cascades, such as the nuclear factor erythroid 2-related factor 2 (Nrf2)-Kelch-like ECH-associated protein 1 (Keap1) pathway, in response to radio- and chemotherapeutic drugs. Nrf2 is a key regulator that protects cells from oxidative stress. Under normal conditions, Nrf2 is tightly bound to Keap1 and is ubiquitinated and degraded by the proteasome. However, under oxidative stress, or when treated with Nrf2 activators, Nrf2 is liberated from the Nrf2-Keap1 complex, translocated into the nucleus, and bound to the antioxidant response element in association with other factors. This cascade results in the expression of detoxifying enzymes, including NADH-quinone oxidoreductase 1 (NQO1) and heme oxygenase 1. NQO1 and cytochrome b5 reductase can neutralize ROS in the plasma membrane and induce a high NAD⁺/NADH ratio, which then activates SIRT1 and mitochondrial bioenergetics. NQO1 can also stabilize the tumor suppressor p53. Given their roles in cancer pathogenesis, redox homeostasis and the metabolic shift from glycolysis to oxidative phosphorylation (through activation of Nrf2 and NQO1) seem to be good targets for cancer therapy. Therefore, Nrf2 modulation and NQO1 stimulation could be important therapeutic targets for cancer prevention and treatment.

Knockdown of KRT17 decreases osteosarcoma cell proliferation and the Warburg effect via the AKT/mTOR/HIF1α pathway

Keratins are fibrous structural proteins that serve essential roles in forming the stratum corneum and protect the cells in this layer of skin from damage. Keratin 17 (KRT17) is a key member of the keratins, and dysregulated expression of KRT17 has been reported in various types of cancer, such as lung and gastric cancer. The present study aimed to identify the role of KRT17 in osteosarcoma and the underlying molecular mechanism. The expression of KRT17 in osteosarcoma tissues and cell lines was detected using reverse transcription‑quantitative PCR (RT‑qPCR) and western blotting. The effects of KRT17 on osteosarcoma cell proliferation and the Warburg effect in vitro were detected using CCK‑8 and colony formation assays, cell cycle distribution analysis and metabolic measures. The effects of KRT17 on osteosarcoma cell proliferation in vivo were detected using a subcutaneous tumorigenesis model. The association between KRT17 and the AKT/mTOR/hypoxia‑inducible factor 1α (HIF1α) pathway was detected using RT‑qPCR and western blotting. The results demonstrated that KRT17 was highly expressed in osteosarcoma tissues and cell lines. Knockdown of KRT17 decreased osteosarcoma cell proliferation and colony formation, induced G1 phase arrest and inhibited glycolysis in vitro. Similarly, the suppression of KRT17 decreased osteosarcoma tumor growth in vivo. Knockdown of KRT17 decreased the expression of phosphorylated (p)‑AKT, p‑mTOR, HIF1α and the target gene of HIF1α glucose transporter 1. Restoring the expression of p‑AKT, p‑mTOR or HIF1α reversed the effect of KRT17 inhibition on cell proliferation and glycolysis. These results indicated that knockdown of KRT17 may be an effective method for treating osteosarcoma through inhibiting osteosarcoma cell proliferation and the Warburg effect by suppressing the AKT/mTOR/HIF1α pathway.

Sinomenine Inhibits Non-Small Cell Lung Cancer via Downregulation of Hexokinases II-Mediated Aerobic Glycolysis

Background

Addiction to aerobic glycolysis is a common metabolic phenotype in human non-small cell lung cancer (NSCLC). The natural product Sinomenine (Sin) exhibits significant anti-tumor effects in various human cancers. However, the underlying mechanism remains elusive.

Methods

The inhibitory effect of Sin on NSCLC cells was determined by MTS and soft agar assays. The glycolysis efficacy of NSCLC cells was examined by glucose uptake and lactate production. The activation of Akt signaling and the protein level of hexokinases II (HK2) were examined by immunoblot (IB), qRT-PCR, and immunohistochemical staining (IHC). The in vivo anti-tumor effect of Sin was validated by the xenograft mouse model.

Results

We showed that HK2 is highly expressed in NSCLC tissues and cell lines. Depletion of HK2 suppressed cell viability, anchorage-independent colony formation, and xenograft tumor growth. Sinomenine exhibited a profound inhibitory effect on NSCLC cells by reducing HK2-mediated glycolysis both in vitro and in vivo. Ectopic overexpression of HK2 compromised these anti-tumor efficacies in sinomenine-treated NSCLC cells. Moreover, we revealed that sinomenine decreased Akt activity, which caused the down-regulation of HK2-mediated glycolysis. Knockdown of Akt reduced HK2 protein level and impaired glycolysis. In contrast, overexpression of constitutively activated Akt1 reversed this phenotype.

Conclusion

This study suggests that targeting HK2-mediated aerobic glycolysis is required for sinomenine-mediated anti-tumor activity.