Expression Of LDHA Research Articles

Piezo1 Mediates Glycolysis-Boosted Pancreatic Ductal Adenocarcinoma Chemoresistance within a Biomimetic Three-Dimensional Matrix Stiffness.

Pancreatic ductal adenocarcinoma (PDAC) is a lethal cancer with a very low 5-year survival rate, which is partially attributed to chemoresistance. Although the regulation of chemoresistance through biochemical signaling is well-documented, the influence of three-dimensional (3D) matrix stiffness is poorly understood. In this study, gelatin methacrylate (GelMA) hydrogels were reconstructed with stiffnesses spanning the range from normal to cancerous PDAC tissues, which are termed as the soft group and stiff group. The PDAC cell lines (Mia-PaCa2 and CFPAC-1) encapsulated in the stiff group displayed a chemoresistance phenotype and were prominent against gemcitabine. RNA-sequencing and bioinformatics analysis indicated that glycolysis was apparently enriched in the stiff group versus the soft group, which was also validated through assays of glucose uptake, lactate production, and the expression of GLUT2, HK2, and LDHA. A rescue assay with 2-deoxy-d-glucose and N-acetylcysteine demonstrated that glycolysis is involved in chemoresistance. Furthermore, the expression of Piezo1 and the content of Ca2+ were elevated in the stiff group. The addition of Yoda1 (Piezo1 agonist) in the soft group promoted glycolysis, whereas in the stiff group, treatment with GsMTx4 (Piezo1 inhibitor) inhibited glycolysis, which showcased that Piezo1 participated in 3D matrix stiffness-induced glycolysis. Taken together, Piezo1-mediated glycolysis was involved in PDAC chemoresistance triggered by the 3D matrix stiffness. Our study sheds light on the mechanism underlying chemoresistance in PDAC from the perspective of 3D mechanical cues.

Nampt/SIRT2/LDHA pathway-mediated lactate production regulates follicular dysplasia in polycystic ovary syndrome

Decreased nicotinamide adenine dinucleotide (NAD+) content has been shown to contribute to metabolic dysfunction during aging, including polycystic ovary syndrome (PCOS). However, the effect of NAD+ on ovulatory dysfunction in PCOS by regulating glycolysis has not been reported. Based on the observations of granulosa cells (GCs) transcriptome data from the Gene Expression Omnibus (GEO) database, the signal pathways including glycolysis and nicotinate-nicotinamide metabolism were significantly enriched, and most genes of the above pathway like LDHA and SIRT2 were down-regulated in PCOS patients. Therefore, the PCOS rat model was established by combining letrozole with a high-fat diet (HFD), we demonstrate that in vivo supplementation of nicotinamide mononucleotide (NMN) significantly improves the ovulatory dysfunction by facilitating the follicular development, promoting luteal formation, as well the fertility in PCOS rats. Furthermore, target energy metabolomics and transcriptome results showed that NMN supplementation ameliorates the lactate production by activating glycolytic process in the ovary. In vitro, when NAD+ synthesis and SIRT2 expression were inhibited, lactate content in KGN cells was decreased and LDHA expression was significantly inhibited. We confirmed that FK866 can enhance the acetylation of LDHA on 293T cells by Co-immunoprecipitation (Co-IP) assay. We also observed that inhibition of NAD+ synthesis can reduce the activity and increase the apoptosis of KGN cells. Overall, these benefits of NMN were elucidated and the Nampt/SIRT2/LDHA pathway mediated lactate production in granulosa cells played an important role in the improvement of follicular development disorders in PCOS. This study will provide experimental evidence for the clinical application of NMN in the treatment of PCOS in the future.

RHOF promotes Snail1 lactylation by enhancing PKM2-mediated glycolysis to induce pancreatic cancer cell endothelial–mesenchymal transition

BackgroundThe influence of the small Rho GTPase Rif (RHOF) on tumor growth, glycolysis, endothelial–mesenchymal transition (EMT), and the potential mechanism of RHOF in pancreatic cancer (PC) were explored.MethodsRHOF expression in PC tissues and cells was assessed by qRT-PCR and western blotting. The viability, proliferation, apoptosis, migration, and invasion of PC cells were assessed using CCK-8, colony formation, EdU, flow cytometry, scratch, and Transwell assays. The expression of EMT- and glycolysis-related proteins was determined using western blotting. The potential mechanisms of action of RHOF in PC were identified using bioinformatic analysis. The effects of RHOF were assessed in vivo using a xenograft mouse model.ResultsPC cell proliferation, migration, and invasion are accelerated by RHOF overexpression, which inhibited apoptosis. RHOF overexpression promoted EMT and glycolysis as evidenced by a decrease in E-cadherin expression and an increase in N-cadherin, Vimentin, HK2, PKM2, and LDHA expression. Bioinformatic analysis indicated that RHOF activated EMT, glycolysis, and Myc targets and that c-Myc could bind to the PKM2 promoter. RHOF overexpression promotes the lactylation and nuclear translocation of Snail1. Silencing Snail1 reversed the promoting effects of RHOF and lactate on cell migration, invasion, and EMT. Moreover, in vivo tumor growth and EMT were inhibited by RHOF silencing.ConclusionRHOF plays an oncogenic role in PC. c-Myc is upregulated by RHOF and promotes PKM2 transcription. PKM2 further induces glycolysis, and the lactate produced by glycolysis causes the lactylation of Snail1, ultimately promoting EMT.

Integrated analysis of single-cell RNA-seq and bulk RNA-seq revealed key genes for bone metastasis and chemoresistance in prostate cancer.

Prostate cancer (PCa) is a serious malignancy. The main causes of PCa aggravation and death are unexplained resistance to chemotherapy and bone metastases. This study aimed to investigate the molecular mechanisms associated with the dynamic processes of progression, bone metastasis, and chemoresistance in PCa. Through comprehensive analysis of single-cell RNA sequencing (scRNA-seq) data, Gene Expression Omnibus (GEO) tumor progression and metastasis-related genes were identified. These genes were subjected to lasso regression modeling using the Cancer Genome Atlas (TCGA) database. Tartrate-resistant acid phosphatase (TRAP) staining and real-time quantitative PCR (RT-qPCR) were used to evaluate osteoclast differentiation. CellMiner was used to confirm the effect of LDHA on chemoresistance. Finally, the relationship between LDHA and chemoresistance was verified using doxorubicin-resistant PCa cell lines. 7928 genes were identified as genes related to tumor progression and metastasis. Of these, 7 genes were found to be associated with PCa prognosis. The scRNA-seq and TCGA data showed that the expression of LDHA was higher in tumors and associated with poor prognosis of PCa. In addition, upregulation of LDHA in PCa cells induces osteoclast differentiation. Additionally, high LDHA expression was associated with resistance to Epirubicin, Elliptinium acetate, and doxorubicin. Cellular experiments demonstrated that LDHA knockdown inhibited doxorubicin resistance in PCa cells. LDHA may play a potential contributory role in PCa initiation and development, bone metastasis, and chemoresistance. LDHA is a key target for the treatment of PCa.

TRIM33 promotes glycolysis through regulating P53 K48-linked ubiquitination to promote esophageal squamous cell carcinoma growth

Esophageal squamous cell carcinoma (ESCC) is a common fatal malignant tumor of the digestive tract; however, its pathogenic mechanism is unknown and lacks specific molecular diagnosis and treatment. Therefore, it is particularly important to identify new tumor biomarkers to enhance the early diagnosis and molecular-targeted therapy of ESCC. Here, we found that the E3 ubiquitin ligase Tripartitemotif-containing33 (TRIM33) is highly expressed in ESCC tissues and cell lines, and is associated with adverse clinical outcomes. We determined that TRIM33 drives aerobic glycolysis to promote tumor growth in vivo and in vitro. In terms of mechanism, TRIM33 binds to p53 to inhibit its stability and promote the expression of downstream glycolysis target genes GLUT1, HK2, PKM2, and LDHA. In addition, TRIM33 promotes the polyubiquitination of P53 K48-linked and proteasome degradation. Further studies have shown that the K351 site of P53 is the key site mediating the ubiquitination of P53 K48-linked to promote aerobic glycolysis in ESCC and tumor cell growth. Our results reveal that the TRIM33-P53 signal axis regulates glycolysis during ESCC and may provide a new perspective for the diagnosis and treatment of ESCC.

NAT10/ac4C/JunB facilitates TNBC malignant progression and immunosuppression by driving glycolysis addiction

BackgroundN4-Acetylcytidine (ac4C), a highly conserved post-transcriptional mechanism, plays a pivotal role in RNA modification and tumor progression. However, the molecular mechanism by which ac4C modification mediates tumor immunosuppression remains elusive in triple-negative breast cancer (TNBC).MethodsNAT10 expression was analyzed in TNBC samples in the level of mRNA and protein, and compared with the corresponding normal tissues. ac4C modification levels also measured in the TNBC samples. The effects of NAT10 on immune microenvironment and tumor metabolism were investigated. NAT10-mediated ac4C and its downstream regulatory mechanisms were determined in vitro and in vivo. The combination therapy of targeting NAT10 in TNBC was further explored.ResultsThe results revealed that the loss of NAT10 inhibited TNBC development and promoted T cell activation. Mechanistically, NAT10 upregulated JunB expression by increasing ac4C modification levels on its mRNA. Moreover, JunB further up-regulated LDHA expression and facilitated glycolysis. By deeply digging, remodelin, a NAT10 inhibitor, elevated the surface expression of CTLA-4 on T cells. The combination of remodelin and CTLA-4 mAb can further activate T cells and inhibite tumor progression.ConclusionTaken together, our study demonstrated that the NAT10-ac4C-JunB-LDHA pathway increases glycolysis levels and creates an immunosuppressive tumor microenvironment (TME). Consequently, targeting this pathway may assist in the identification of novel therapeutic strategies to improve the efficacy of cancer immunotherapy.

Serinc2 Drives the Progression of Cervical Cancer Through Regulating Myc Pathway.

As one of the most common malignancies, cervical cancer (CC) seriously affects women's health. This study aimed to investigate the biological function of Serinc2 in CC. Serinc2 expression was surveyed utilizing immunohistochemistry, western blot, and qRT-PCR. CC cell viability, invasion, proliferation, migration, and apoptosis, were detected via CCK-8, Transwell assay, colony formation, wound healing assay, and flow cytometry. Glucose consumption, lactate production, and ATP levels were determined by the corresponding kit. The protein expression of c-Myc, PDK1, HK2, PFKP, LDHA, Snail, Vimentin, N-cadherin, and E-cadherin was detected via western blot. The interaction between the promoter of PFKP and Myc was confirmed through luciferase reporter assay and Chip assay. Invivo, to evaluate the function of Serinc2 on tumor growth, a xenograft mouse model was used. In CC tissues and cells, Serinc2 was upregulated. In CC cells, knockdown of Serinc2 suppressed cell invasion, proliferation, migration, decreased the expression of Snail, Vimentin, N-cadherin, HK2, PFKP, LDHA, and PDK1, increased E-cadherin expression, reduced glucose consumption and the production of lactate and ATP, and induced cell apoptosis; Serinc2 overexpression led to the opposite results. Mechanically, Serinc2 promoted Myc expression, and Myc induced PFKP expression. Furthermore, overexpressed Myc abolished the inhibitive influences of Serinc2 knockdown on the malignant behaviors of CC cells. Additionally, knockdown of Serinc2 inhibited tumor growth and reduced the protein expression of c-Myc, PFKP, LDHA, and PDK1 invivo. Knockdown of Serinc2 inhibited the malignant progression of CC, which was achieved via Myc pathway. Our study provides novel insight into CC pathogenesis.

Sini decoction-polysaccharide compound regulates proliferation, apoptosis, and glycolysis of liver cancer cells through PHLDA2/ANXA2.

Sini decoction (SND), a popular formula from traditional Chinese medicine (TCM), plays a critical role in the treatment of liver disease. Its protective effect for the heart against cardiovascular diseases is well documented. However, its effects and pharmacological mechanisms for the liver remain unclear. This study aimed to clarify the effect and mechanism of the SND-polysaccharide compound (SNDPC) on hepatocellular carcinoma (HCC). Different genes affected by SNDPC in HCC were analyzed via Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Databases including Multi-Experiment Matrix (MEM), HCCDB, LinkedOmics, and Gene Expression Profiling Interactive Analysis (GEPIA) were used to determine the correlation between PHLDA2 and ANXA2. Cell proliferation and viability were identified using Cell Counting Kit-8 (CCK-8). Cell apoptosis was estimated using terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay and Western blotting. Glycolysis was determined by measuring glucose uptake, lactate concentration, extracellular acidification rate (ECAR), and the expressions of LHDA, HK2, and PKM2. The binding between PHLDA2 and ANXA2 was identified by coimmunoprecipitation. SNDPC significantly weakened cell proliferation, facilitated cell apoptosis, and suppressed glycolysis by reducing glucose uptake, lactate concentration, ECAR, and the expressions of LDHA, HK2, and PKM2 in HCC cells. Furthermore, PHLDA2 was predicted to bind to ANXA2, which was confirmed by coimmunoprecipitation. SNDPC reduced the expressions of PHLDA2 and ANXA2 in HCCLM3 cells, and PHLDA2 silencing decreased the proliferation of cells, promoted cell apoptosis, and inhibited glycolysis of HCCLM3 cells while reversing the overexpression of PHLDA2. SNDPC suppressed proliferation and glycolysis while accelerating the apoptosis of HCC cells through PHLDA2/ANXA2.

PYGL regulation of glycolysis and apoptosis in glioma cells under hypoxic conditions via HIF1α-dependent mechanisms.

Gliomas are highly aggressive brain tumors with complex metabolic and molecular alterations. The role of glycolysis in glioma progression and its regulation by hypoxia remain poorly understood. This study investigated the function of glycogen phosphorylase L (PYGL) in glioma and its interaction with glycolytic pathways under hypoxic conditions. Differential expression analysis was conducted using The Cancer Genome Atlas (TCGA) glioma and GSE67089 datasets, revealing significant changes in the expression of genes. A prognostic risk model incorporating PYGL was built by univariate and multivariate Cox regression analyses. The impacts of PYGL on glioma cell proliferation, glycolysis, apoptosis, and metabolic activities were evaluated by in vitro assays. Additionally, the influences of hypoxia and hypoxia-inducible factor 1-alpha (HIF1α) on PYGL expression were evaluated. Our prognostic prediction model showed a C-index of 0.76 [95% confidence interval (CI): 0.70-0.82], indicating a good predictive accuracy of the model. In addition, genetic predictors included in the nomogram included PYGL, HIF1α, and other genes associated with the glycolytic pathway. Differential expression analysis identified PYGL as a key gene associated with glioma survival. PYGL expression was significantly upregulated in glioma cells. PYGL knockdown inhibited cell invasion, proliferation, migration, and colony formation and enhanced apoptosis via modulation of Bcl-2, caspase-3, and Bax. Glycolysis was impaired in PYGL-knockdown cells, as indicated by increased glycogen levels and a reduced extracellular acidification rate (ECAR), adenosine triphosphate (ATP) levels, lactate levels, and PKM2 and LDHA expression. PYGL overexpression promoted glycolysis and cell viability, which was counteracted by 2-deoxy-D-glucose (2-DG). Hypoxia-induced PYGL expression was regulated by HIF1α, underscoring the interplay between the hypoxia and glycolysis pathways. PYGL is a crucial regulator of glycolysis in gliomas and contributes to tumor progression under hypoxic conditions. Targeting PYGL and its associated metabolic pathways may offer new therapeutic strategies for glioma treatment.

Competing Endogenous TMPO-AS1-let-7c-5p- LDHA RNA Network Predicts the Prognosis of Lung Adenocarcinoma Patients.

Lactate dehydrogenase is dysregulated in several cancer types. However, the mechanism of its dysregulation in lung cancer is not fully understood. We utilized web-based computational databases to conduct gene expression analysis on LDHA, identified its regulator, and explored their role in the prognosis of lung cancer. We used various web-based computational tools, including the UALCAN, TIMER2.0, ENCORI, TCGA Portal, OncoDB, and GEPIA2 datasets for lung cancer analysis in this study. We also performed survival, biological processes, and metastasis analysis using various computational tools. We also carried out co-expression functional enrichment analysis using the Enrichr and TIMER databases, multivariate analysis of survival and pathological stage, and transcriptional regulation analysis using the ENCORI and OncoDB datasets. Furthermore, LDHA inhibitor binding of withanolides was analyzed using Auto Dock Tools 1.5.6, LigPlot+, and Pymol. The study found that the higher levels of LDHA gene expression were associated with poor prognosis and overall survival in lung cancer patients. We identified 11 key genes co-expressed with LDHA; out of them, two genes, MKI67 and PGK1, showed a strong positive correlation with LDHA and associated poor survival outcomes in LUAD patients. Furthermore, we also identified hsa-let-7c-5p and TMPO-AS1 as potential regulators of LDHA in LUAD. It might be possible that the TMPO-AS1- hsa-let-7c-5p-LDHA ceRNA network could serve as a potential regulator of aerobic glycolysis in LUAD and can serve as prognostic biomarkers. Further, Withanolides can inhibit the activity of LDHA and can be tested as an adjuvant treatment. We conclude that LDHA is overexpressed in LUAD, and the patients with high expression of LDHA exhibit poor prognosis. Further, the TMPO-AS1-hsa-let-7c-5p-LDHA ceRNA network can regulate aerobic glycolysis, thereby facilitating tumor growth in lung cancer.

PAF1/HIF1α axis rewires the glycolytic metabolism to fuel aggressiveness of pancreatic cancer

BackgroundPAF1/PD2 deregulation contributes to tumorigenesis, drug resistance, and cancer stem cell maintenance in Pancreatic Cancer (PC). Recent studies demonstrate that metabolic reprogramming plays a role in PC progression, but the mechanism is poorly understood. Here, we focused on examining the role of PAF1/PD2 in the metabolic rewiring of PC.MethodsCell lines were transfected with shRNAs to knockdown PAF1/PD2. Metabolic genes regulated by PAF1/PD2 were identified by qPCR/western blot, and metabolic assays were performed. Immunoprecipitations/ChIP were performed to identify PAF1/PD2 protein partners and confirm PAF1/HIF1α sub-complex binding to LDHA.ResultsPAF1 and LDHA showed progressively increased expression in human pancreatic tumor sections. Aerobic glycolysis genes were downregulated in PAF1-depleted PC cells. Metabolic assays indicated a decreased lactate production and glucose uptake in knockdown cells. Furthermore, PAF1/PD2 depletion showed a reduced glycolytic rate and increased oxidative phosphorylation by ECAR and OCR analysis. Interestingly, we identified that HIF1α interacts and co-localizes with PAF1, specifically in PC cells. We also observed that the PAF1/PD2-HIF1α complex binds to the LDHA promoter to regulate its expression, reprogramming the metabolism to utilize the aerobic glycolysis pathway preferentially.ConclusionOverall, the results indicate that PAF1/PD2 rewires PC metabolism by interacting with HIF1α to regulate the expression of LDHA.

LncRNA TMPO-AS1 Promotes Triple-Negative Breast Cancer by Sponging miR-383-5p to Trigger the LDHA Axis.

Understanding the heterogeneous nature of breast cancer, including the role of LDHA expression regulation via non-coding RNAs in prognosis, is still unknown, highlighting the need for more research into its molecular roles and diagnostic approaches. The study utilized various computer tools to analyze the differences between LDHA in tissues and cancer cells. It used data from TIMER 2.0, UALCAN, and TISIDB to study gene expression and survival outcomes in breast cancer patients. The study also used the Breast Cancer Gene Expression Miner to examine the relationship between LDHA gene expression and breast cancer type. Other tools included TCGAPortal, TNMplot, ctcRbase, GSCA, Enrichr, TISIDB, Oncomx, and TANRIC. The study then explored the relationship between tumor-infiltrating immune cells and LDHA formation using the GSCA and TISIDB repositories. We used Auto Dock Tools 1.5.6 to perform ligand binding analysis for LDHA, withanolides, and the known inhibitor LDH-IN-1. LigPlot+ and Pymol were used for visualization of protein-ligand complexes. LDHA overexpression in breast cancer cells, metastatic tissue, and circulating tumor cells leads to shortened recurrence-free survival, overall survival, and distant metastasis-free survival. In invasive breast cell carcinoma, we observed that LDHA/HIF-1α /TMPO-AS1 are overexpressed while miR-383-5p is downregulated. This overexpression is associated with poor prognosis and may lead to Act_DC infiltration into the tumor microenvironment. Withanolides, viz., Withaferine A and Withanolide D, have shown high binding affinity with LDHA, with binding energies of -9.3kcal/mol and -10kcal/mol respectively. These could be attractive choices for small-molecule inhibitor design against LDHA.

Exploring the Anticancer Potential of Astragalin in Triple Negative Breast Cancer Cells by Attenuating Glycolytic Pathway through AMPK/mTOR.

Aerobic glycolysis is crucial for cancer cells to survive, grow, and progress. In the current study, the anti-cancer effects of astragalin (ASG) on breast cancer cells and in the glycolytic pathway through AMPK/mTOR have been evaluated. The objective of this study was to examine the impact of ASG, a natural flavonoid, on glycolysis via targeting AMPK/mTOR signalling in MDA-MB-231 breast cancer cells. The study utilized ASG, which was isolated from Haplophyllum tuberculatum. The cells were treated with different concentrations of ASG (20 and 40 μg/mL), and anti- glycolytic activities were measured through cell proliferation, expression of glycolytic enzymes (HK-2, LDH-A, GLUT-1), glucose uptake, and lactate concentration assays. The MTT assay was used to assess cellular proliferation, while the glucose uptake and lactate levels were determined by employing colorimetric assays. The mRNA expression of target glycolytic enzymes was determined by qRT-PCR. The protein levels of glycolytic targets, as well as that of AMPK and mTOR, were determined by western blot. in silico docking of ASG was done with mTOR and AMPK proteins. Astragalin exhibited dose- and time-dependent anti-proliferative effects in MDA-MB-231 cells. In breast cancer cells, the mRNA and protein expression of GLUT-1, LDH-A, and HK-2 were all significantly downregulated after receiving ASG treatments. Furthermore, after ASG treatments, MDA-MB231 cells showed a significant decrease in lactate and glucose uptake compared to control cells. Mechanistically, ASG increased AMPK activation and suppressed mTOR activation in these cells. The inhibitory role of ASG on aerobic glycolysis was prevented by treatments with compound C (an AMPK inhibitor). However, combined treatment of compound C and ASG could nullify the ASG-induced anti-glycolysis effect and restore the level of p-AMPK and p-mTOR in MDA-MB231 cells. The results from molecular docking predicted that ASG had the potential to bind AMPK and mTOR, with free energy for binding, -8.2 kcal/mol and -8.1 kcal/mol, respectively. Taken together, the findings from this study indicated that ASG might modulate the AMPK/mTOR pathway to inhibit aerobic glycolysis and proliferation of MDAMB231 breast cancer.

Immunometabolic alteration of CD4+ T cells in the pathogenesis of primary Sjögren’s syndrome

Primary Sjögren’s syndrome (pSS) is a prevalent autoimmune disorder wherein CD4+ T cells play a pivotal role in its pathogenesis. However, the underlying mechanisms driving the hyperactivity of CD4+ T cells in pSS remain poorly understood. This study aimed to investigate the potential role of immunometabolic alterations in driving the hyperactivity of CD4+ T cells in pSS. We employed Seahorse XF assay to evaluate the metabolic phenotype of CD4+ T cells, conducted flow cytometry to assess the effector function and differentiation of CD4+ T cells and measured the level of intracellular reactive oxygen species (ROS). Additionally, transcriptome sequencing, PCR, and Western blotting were utilized to examine the expression of glycolytic genes. Our investigation revealed that activated CD4+ T cells from pSS patients exhibited elevated aerobic glycolysis, rather than oxidative phosphorylation, resulting in excessive production of IFN-γ and IL-17A. Inhibition of glycolysis by 2-Deoxy-D-glucose reduced the expression of IFN-γ and IL-17A in activated CD4+ T cells and mitigated the differentiation of Th1 and Th17 cells. Furthermore, the expression of glycolytic genes, including CD3E, CD28, PIK3CA, AKT1, mTOR, MYC, LDHA, PFKL, PFKFB3, and PFKFB4, was upregulated in activated CD4+ T cells from pSS patients. Specifically, the expression and activity of LDHA were enhanced, contributing to an increased level of intracellular ROS. Targeting LDHA with FX-11 or inhibiting ROS with N-acetyl-cysteine had a similar effect on reversing the dysfunction of activated CD4+ T cells from pSS patients. Our study unveils heightened aerobic glycolysis in activated CD4+ T cells from pSS patients, and inhibition of glycolysis or its metabolite normalizes the dysfunction of activated CD4+ T cells. These findings suggest that aerobic glycolysis may be a promising therapeutic target for the treatment of pSS.

Lipocalin-2 induced LDHA expression promotes vascular remodelling in pulmonary hypertension.

Aerobic glycolysis is involved in the pathogenesis of pulmonary hypertension (PH). The mechanisms by which glycolysis is increased and how it contributes to pulmonary vascular remodelling are not yet fully understood. In this study, we demonstrated that elevated lipocalin-2 (LCN2) in PH significantly enhances aerobic glycolysis in human pulmonary artery smooth muscle cells (PASMCs) by up-regulating LDHA expression. Knockout of Lcn2 or having heterozygous LDHA deficiency in mice significantly inhibits the progression of hypoxic PH. Our study reveals that LCN2 stimulates LDHA expression by activating Akt-HIF-1α signalling pathway. Inhibition of Akt or HIF-1α reduces LDHA expression and proliferation of PASMCs. Both Akt and HIF-1α play critical roles in the development of PH and are suppressed in the pulmonary vessels of hypoxic PH mice lacking LCN2. These findings shed light on the LCN2-Akt-HIF1α-LDHA axis in aerobic glycolysis in PH.

PFKL promotes cell viability and glycolysis and inhibits cisplatin chemosensitivity of laryngeal squamous cell carcinoma

Laryngeal squamous cell carcinoma (LSCC) with a high incidence and mortality rate, has a serious impact worldwide. Phosphofructokinase-1 liver type (PFKL) is a major enzyme in glycolysis progress, but its role in modulating tumorigenesis and cisplatin (DDP) chemosensitivity of LSCC was still unclear. The mRNA and protein levels of PFKL were detected by qRT-PCR and immunohistochemical assay. Cell Counting Kit-8 assay and flow cytometry were carried out to observe cell viability, as well as apoptosis and mitochondrial reactive oxygen species (mito-ROS). Extracellular acidification rate and lactate content were measured using extracellular flux analysis and lactate assay kit. Immunofluorescent staining was used to evaluate the expression of γ-H2AX foci. DNA damage was detected via single-cell gel electrophoresis. Western blotting was introduced to evaluate the protein level of PFKL, LDHA, γ-H2AX, cleaved PARP, H3K27ac, and H3K9ac. Mice xenograft model of LSCC was built for in vivo validation. The PFKL expression was significantly increased in LSCC and associated with poor survival of LSCC patients. Knockdown of PFKL in LSCC cells significantly inhibited cell viability, ECAR, lactate content, and LDHA expression, but promoted mito-ROS level. Furthermore, knockdown of PFKL enhanced response of LSCC cells to DDP by increasing DDP-induced apoptosis, promoting DDP-induced mito-ROS level, γ-H2AX foci, tail DNA, and the expression of γ-H2AX and cleaved PARP. However, the overexpression of PFKL in LSCC cells had opposite experimental results. Nude mice tumor formation experiment proved that downregulation of PFKL significantly enhanced response of cells to DDP, demonstrated by reduced tumor volume, weight and increased TUNEL-positive cells. Suppression of CBP/EP300-mediated PFKL transcription inhibited cell viability and glycolysis and promoted mito-ROS in LSCC. PFKL promotes cell viability and DNA damage repair in DDP-treated LSCC through regulation of glycolysis pathway.

Ras-dependent activation of BMAL2 regulates hypoxic metabolism in pancreatic cancer.

To identify drivers of malignancy in human pancreatic ductal adenocarcinoma (PDAC), we performed regulatory network analysis on a large collection of expression profiles from laser capture microdissected samples of PDAC and benign precursors. We discovered that BMAL2 plays a role in the initiation, progression, post resection survival, and KRAS activity in PDAC. Functional analysis of BMAL2 target genes led us to hypothesize that it plays a role in regulating the response to hypoxia, a critical but poorly understood feature of PDAC physiology. Knockout of BMAL2 in multiple human PDAC cell lines revealed effects on viability and invasion, particularly under hypoxic conditions. Loss of BMAL2 also affected glycolysis and other metabolic processes. We found that BMAL2 directly regulates hypoxia-responsive target genes. We also found that BMAL2 is necessary for the stabilization of HIF1A upon exposure to hypoxia, but destabilizes HIF2A under hypoxia. These data demonstrate that BMAL2 is a master transcriptional regulator of hypoxia responses in PDAC and may serve as a long-sought molecular switch that distinguishes HIF1A- and HIF2A-dependent modes of hypoxic metabolism.

Overexpression of ubiquitin-conjugating enzyme 2T induces radiotherapy resistance in hepatocellular carcinoma by enriching regulatory T cells in the tumor microenvironment

To investigate the effect of overexpression of ubiquitin-conjugating enzyme 2T (UBE2T) on radiosensitivity of hepatocellular carcinoma (HCC). Hepa1-6 cells were transfected with a UBE2T-overexpressing or a control lentiviral vector, and the changes in their radiotherapy sensitivity and concentrations of glucose and lactate in the supernatant were assessed using colony-forming assay and colorimetric assay. The transfected cells were inoculated subcutaneously in nude mice or C57BL/6 mice, and tumor growth following irradiation were recorded. The xenografts were collected for analyzing infiltration of CD4+ T cells and regulatory T cells (Tregs) using flow cytometry and detecting expressions of HK1 and LDHA using Western blotting. The correlations of UBE2T expression with immune cell infiltration, glycolysis and Tregs in HCC were analyzed using CIBERSORT algorithm and TCGA database, and the results were verified in a co-culture system of Hepa1-6 cells and Tregs. UBE2T overexpression caused radiotherapy resistance in both cultured Hepa1-6 cells and xenografts in the tumor-bearing mouse models (especially in C57BL/6 mice). CIBERSORT analysis suggested that a high expression of UBE2T was associated with increased percentages of dendritic cells, T follicular helper cells, M2 macrophages, monocytes, lymphocytes and Tregs in HCC. The UBE2T-overexpressing xenografts showed an increased percentage of Tregs and enhanced expressions of HK1 and LDHA, and irradiation increased infiltration of CD4+ T cells and Tregs in the tumor microenvironment. Hepa1-6 cells overexpressing UBE2T showed a decreased glucose concentration and an increased lactate concentration. GSEA analysis suggested that a high UBE2T expression was positively correlated with increased glycolysis and Tregs infiltration in HCC. In the cell co-culture system, UBE2T overexpression significantly enhanced lactate production, proliferation and immunosuppressive functions of Tregs. A high UBE2T expression results in radiotherapy resistance of HCC possibly by enhancing glycolysis and cause enrichment of Tregs in the tumor microenvironment.

The miR-199a-5p/HIF1α dual-regulatory axis participates in hypoxia-induced aggressive phenotypes of oral squamous cell carcinoma (OSCC) cells.

The late-stage diagnosis and distant metastasis of oral squamous cell carcinoma (OSCC) remain a huge challenge to clinical treatment for OSCC. During the past decades, targeting glycolysis-inducing factors becomes an attractive new strategy in OSCC therapies. OSCC cells were stimulated with hypoxia or transfected with agomir-199a-5p, antagomir-199a-5p, and siRNA for HIF1A, cell proliferation was detected by CCK-8 assay; HIF1α, GLUT1, HK2 and LDHA expression levels were examined with western blot; miR-199 expression was determined with RT-PCR; cell migratory and invasive abilities were examined using wound healing and transwell assays; the lactate and glucose in culture medium were also determined. Luciferase assay or CHIP assay was applied for confirm the binding between miR-199a-5p and HIF1A 3'UTR, or between HIF1α and miR-199a promoter. HIF1α showed to be abnormally up-regulated, and miR-199a-5p showed to be abnormally down-regulated within OSCC under hypoxia. Hypoxia considerably enhanced OSCC cell proliferation, glycolysis, migratory ability, and invasive ability. MiR-199a-5p bound to HIF1A 3'-UTR and suppressed HIF1A expression; HIF1α targeted miR-199a-5p promoter region and downregulated miR-199a-5p expression. Under hypoxia, miR-199a-5p overexpression significantly repressed HIF1α up-regulation inresponse to hypoxia, OSCC cell proliferation, glycolysis, migratory ability, and invasive ability. miR-199a-5p and HIF1α form a dual-regulatory axis in OSCC cells; the miR-199a-5p/HIF1α dual-regulatory axis contributes to hypoxia-induced aggressive OSCC phenotypes.

Inactivation of KDM6A promotes the progression of colorectal cancer by enhancing the glycolysis

KDM6A (lysine demethylase 6A) has been reported to undergo inactivating mutations in colorectal cancer, but its function in the progression of colorectal cancer has not been evaluated using animal models of colorectal cancer. In this study, we found that knocking out KDM6A expression in mouse intestinal epithelium increased the length of villus and crypt, promoting the development of AOM (azoxymethane)/DSS (dextran sulfate sodium salt)-induced colorectal cancer. On the other hand, knocking down KDM6A expression promoted the growth of colorectal cancer cells. In molecular mechanism studies, we found that KDM6A interacts with HIF-1α; knocking down KDM6A promotes the binding of HIF-1α to the LDHA promoter, thereby promoting LDHA expression and lactate production, enhancing glycolysis. Knocking down LDHA reversed the malignant phenotype caused by KDM6A expression loss. In summary, this study using animal models revealed that KDM6A loss promotes the progression of colorectal cancer through reprogramming the metabolism of the colorectal cancer cells, suggesting that restoring the function of KDM6A is likely to be one of the strategies for colorectal cancer treatment.