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Homeobox C4 (HOXC4) is a member of homeobox family and acts as a transcription factor in regulating morphological development. The current study aimed to determine its role in pancreatic cancer (PC). Bioinformatics analysis was employed to assess the expression and clinical significance of HOXC4 in PC, while the expression of HOXC4 was further confirmed in PC tissues through quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC). The impact of HOXC4 on PC cell proliferation was evaluated using various assays including Cell Counting Kit-8, colony formation, apoptosis detection, cell cycle analysis, and subcutaneous tumorigenesis. Extracellular acidification rate, glucose uptake, and lactate production measurements were detected to examine the impact of HOXC4 on glycolysis. The relationship between HOXC4 and lactate dehydrogenase A (LDHA) was investigated using CHIP assay, luciferase reporter assay, and western blot. Notably, there was a substantial increase in HOXC4 expression in PC, and patients with elevated HOXC4 levels exhibited shorter survival durations. HOXC4 knockdown resulted in significantly reduced proliferation and colony formation in PC cells, accompanied by increased apoptosis and G1 phase arrest. The overexpression of HOXC4 resulted in contrasting effects. In vivo , the proliferation of PC cells was diminished upon the knockdown of HOXC4. HOXC4 exhibited an increase in LDHA expression by binding to its promoter. The suppressive effects of HOXC4 knockdown on PC cells were counteracted upon the restoration of LDHA. In conclusion, HOXC4 promoted the proliferation of PC cells by increasing LDHA-mediated glycolysis. HOXC4 can act as a target for PC therapy.

Aim. To determine the role of Ruk/CIN85 in the control of breast adenocarcinoma cells metabolism, we performed systemic analysis of the activity levels/content of key enzymes/components of glycolysis and oxidative phosphorylation using as a model the weakly invasive human breast adenocarcinoma MCF-7 cell line (Mock); and its sublines with stable overexpression (G4 subline) and reverse down-regulation (G4vir subline) of the adaptor protein. Materials and methods. MCF-7 cells were cultured in the complete DMEM medium under standard conditions. Enzymes activity, content of metabolites and protein in cell extracts and the conditioned cell culture medium were estimated by spectrophotometric and fluorometric assays. Results. First of all, biochemical indexes of aerobic glycolysis, activity levels of some key glycolytic enzymes and metabolites were evaluated. A significant increase in the activity of these enzymes, aldolase A (ALDOA) and lactate dehydrogenase A (LDHA), was found in G4 cells compared to Mock by 1.3 and 1.6 times, respectively. In addition, in the conditioned medium of G4 cells, an increase in lactate content by 1.5 times compared with the control was found, which corresponded to a change in LDHA activity. Knockdown of Ruk/CIN85 expression level in G4 subline resulted in a significant decrease of these parameters compared to G4 cells, ALDOA – 4 times, LDHA - 1.4 times, and lactate production - 2.5 times. It should be noted that in G4vir cells, LDHA activity returned to level of control cells, while ALDOA activity and lactate content additionally decreased by 3 times and 1.6 times, respectively. Therefore, the observed changes in the intensity of glycolysis in MCF-7 sublines positively correlate with the expression level of adaptor protein studied. To assess the metabolic status of mitochondria, the level of activity of the Krebs cycle enzyme, NAD-dependent malate dehydrogenase (MDH2), the catalyst of last stage of the cycle, was determined. A 2-fold decrease in MDH2 activity was found in the MCF-7 G4 subline relative to control Mock cells, as well as an increase in this index by 2.4 times in G4vir cells to control values. Unlike glycolysis, we observed the opposite pattern with respect to the intensity of Krebs cycle reactions depending on the expression level of Ruk/CIN85. Conclusions. The observed reversion of the Warburg metabotype as a result of Ruk/CIN85 downregulation in MCF-7 cells overexpressing adaptor protein is a strong experimental evidence for its regulatory role in energy supply modes, aerobic glycolysis versus OXPHOS in the course cancer cells malignization.

Bladder cancer is the 10th most common cancer worldwide. For muscle‐invasive bladder cancer (MIBC), treatment includes radical cystectomy, radiotherapy, and chemotherapy; however, the outcome is generally poor. For non–muscle‐invasive bladder cancer (NMIBC), tumor recurrence is common. There is an urgent need for more effective and less harmful therapeutic approaches. Here, bladder cancer cell metabolic reprogramming to rely on aerobic glycolysis (the Warburg effect) and expression of associated molecular therapeutic targets by bladder cancer cells of different stages and grades, and in freshly resected clinical tissue, is investigated. Importantly, analyses indicate that the Warburg effect is a feature of both NMIBCs and MIBCs. In two in vitro inducible epithelial‐mesenchymal transition (EMT) bladder cancer models, EMT stimulation correlated with increased lactate production, the end product of aerobic glycolysis. Protein levels of lactate dehydrogenase A (LDH‐A), which promotes pyruvate enzymatic reduction to lactate, were higher in most bladder cancer cell lines (compared with LDH‐B, which catalyzes the reverse reaction), but the levels did not closely correlate with aerobic glycolysis rates. Although LDH‐A is expressed in normal urothelial cells, LDH‐A knockdown by RNAi selectively induced urothelial cancer cell apoptotic death, whereas normal cells were unaffected—identifying LDH‐A as a cancer‐selective therapeutic target for bladder cancers. LDH‐A and other potential therapeutic targets (MCT4 and GLUT1) were expressed in patient clinical specimens; however, positive staining varied in different areas of sections and with distance from a blood vessel. This intratumoral heterogeneity has important therapeutic implications and indicates the possibility of tumor cell metabolic coupling. [ABSTRACT FROM AUTHOR]

Background: Aerobic glycolysis has a pivotal role in the carcinogenic process. The current understanding of the functional role and mechanism of UCHL3-related aerobic glycolysis in pancreatic cancer is far from comprehensive, therefore requires an in-depth analysis on this aspect. Methods: In the present research, the expressions of ubiquitin carboxyl-terminal hydrolase L3 (UCHL3), lactate dehydrogenase A (LDHA) and Forkhead box protein M1 (FOXM1) were detected by qRT-PCR, Western blot and immunohistochemistry. The effects of UCHL3 knockdown or overexpression on pancreatic cancer cells were examined by determining cell viability and colony formation. Aerobic glycolysis was assessed according to glucose uptake, lactic acid production, and lactate dehydrogenase (LDH) activity. Dual-luciferase reporter assay was performed to detect LDHA promoter activity. Results: The results showed that UCHL3 expression was significantly increased in the pancreatic cancer tissues and cells, and that knocking down UCHL3 noticeably inhibited cell viability and aerobic glycolysis. Further investigations revealed that LDHA expression was promoted by UCHL3 and could be reduced by shFOXM1, and that low-expressed LDHA partly reversed the inhibition of aerobic glycolysis induced by overexpressed UCHL3. Conclusions: To conclude, this study demonstrates that UCHL3 plays a carcinogenic role by promoting aerobic glycolysis in pancreatic cancer, suggesting that UCHL3 may be a potential diagnostic and therapeutic target for the treatment of cancer. [ABSTRACT FROM AUTHOR]

Pancreatic beta cells are highly susceptible to oxidative stress, which plays a crucial role in diabetes outcomes. Progress has been slow to identify molecules that could be utilized to enhance cell survival and function under oxidative stress. Itaconate, a byproduct of the tricarboxylic acid cycle, has both anti-inflammatory and antioxidant properties. The effects of itaconate on beta cells under oxidative stress are relatively unknown. We explored the effects of 4-octyl itaconate—a cell-permeable derivative of itaconate—on MIN6 (a beta cell model) under oxidative stress conditions caused by hypoxia, along with its mechanism of action. Treatment with 4-OI reversed hypoxia-induced cell death, reduced ROS production, and inhibited cell death pathway activation and inflammatory cytokine secretion in MIN6 cells. The 4-OI treatment also suppressed lactate dehydrogenase A (LDHA)activity, which increases under hypoxia. Treatment of cells with the ROS scavenger NAC and LDHA-specific inhibitor FX-11 reproduced the beneficial effects of 4-OI on MIN6 cell viability under oxidative stress conditions, confirming its role in regulating ROS production. Conversely, overexpression of LDHA reduced the beneficial effects exerted by 4-OI on cells. Our findings provide a strong rationale for using 4-OI to prevent the death of MIN6 cells under oxidative stress.

Increasing evidence reveals that breast cancer stem cells (BCSCs) subtypes with distinct properties are regulated by their abnormal metabolic changes; however, the specific molecular mechanism and its relationship with tumor microenvironment (TME) are not clear. In this study, we explored the mechanism of lactate dehydrogenase A (LDHA), a crucial glycolytic enzyme, in maintaining cancer stemness and BCSCs plasticity, and promoting the interaction of BCSCs with tumor associated macrophages (TAMs). Firstly, the expression of LDHA in breast cancer tissues was much higher than that in adjacent tissues and correlated with the clinical progression and prognosis of breast cancer patients based on The Cancer Genome Atlas (TCGA) data set. Moreover, the orthotopic tumor growth and pulmonary metastasis were remarkable inhibited in mice inoculated with 4T1-shLdha cells. Secondly, the properties of cancer stemness were significantly suppressed in MDA-MB-231-shLDHA or A549-shLDHA cancer cells, including the decrease of ALDH+ cells proportion, the repression of sphere formation and cellular migration, and the reduction of stemness genes (SOX2, OCT4, and NANOG) expression. However, the proportion of ALDH+ cells (epithelial-like BCSCs, E-BCSCs) was increased and the proportion of CD44+ CD24− cells (mesenchyme-like BCSCs, M-BCSCs) was decreased after LDHA silencing, suggesting a regulatory role of LDHA in E-BCSCs/M-BCSCs transformation in mouse breast cancer cells. Thirdly, the expression of epithelial marker E-cadherin, proved to interact with LDHA, was obviously increased in LDHA-silencing cancer cells. The recruitment of TAMs and the secretion of CCL2 were dramatically reduced after LDHA was knocked down in vitro and in vivo. Taken together, LDHA mediates a vicious cycle of mutual promotion between BCSCs plasticity and TAMs infiltration, which may provide an effective treatment strategy by targeting LDHA for breast cancer patients.

BackgroundMyoglobin (MB) is increasingly recognized as a key player in cancer growth and metastasis. Low oxygen tensions, commonly associated with highly aggressive and recurrent cancers, have been shown to regulate its expression in several cancers such as lung, neck, prostate and breast cancer. However, it is not yet known whether it contributes to the growth and spread of brain cancers especially Glioblastoma multiforme (GBM).MethodsHere we investigate the expression of MB, and its correlation with the hypoxia markers carbonic anhydrase IX (CAIX) and lactate dehydrogenase A (LDHA), in human tissue microarrays of multiple organ tumors, brain tumors, and GBM tumors, and their respective cancer-adjacent normal tissues. Correlation between MB protein expression and tumor grade was also assessed.ResultsWe show that MB protein is expressed in a wide variety of cancers, benign tumors, cancer-adjacent normal tissues, hyperplastic tissue samples and normal brain tissue, and low oxygen tensions modulate MB protein expression in different brain cancers, including GBM. Enhanced nuclear LDHA immune-reactivity in GBM was also observed. Finally, we report for the first time a positive correlation between MB expression and brain tumor grade.ConclusionOur data suggest that hypoxia regulate MB expression in different brain cancers (including GBM) and that its expression is associated with a more aggressive phenotype as indicated by the positive correlation with the brain tumor grade. Additionally, a role for nuclear LDHA in promoting aggressive tumor phenotype is also suggested based on enhanced nuclear expression which was observed only in GBM.

Increasing evidence reveals that breast cancer stem cells (BCSCs) subtypes with distinct properties are regulated by their abnormal metabolic changes; however, the specific molecular mechanism and its relationship with tumor microenvironment (TME) are not clear. In this study, we explored the mechanism of lactate dehydrogenase A (LDHA), a crucial glycolytic enzyme, in maintaining cancer stemness and BCSCs plasticity, and promoting the interaction of BCSCs with tumor associated macrophages (TAMs). Firstly, the expression of LDHA in breast cancer tissues was much higher than that in adjacent tissues and correlated with the clinical progression and prognosis of breast cancer patients based on The Cancer Genome Atlas (TCGA) data set. Moreover, the orthotopic tumor growth and pulmonary metastasis were remarkable inhibited in mice inoculated with 4T1-shLdha cells. Secondly, the properties of cancer stemness were significantly suppressed in MDA-MB-231-shLDHA or A549-shLDHA cancer cells, including the decrease of ALDH+ cells proportion, the repression of sphere formation and cellular migration, and the reduction of stemness genes (SOX2, OCT4, and NANOG) expression. However, the proportion of ALDH+ cells (epithelial-like BCSCs, E-BCSCs) was increased and the proportion of CD44+ CD24− cells (mesenchyme-like BCSCs, M-BCSCs) was decreased after LDHA silencing, suggesting a regulatory role of LDHA in E-BCSCs/M-BCSCs transformation in mouse breast cancer cells. Thirdly, the expression of epithelial marker E-cadherin, proved to interact with LDHA, was obviously increased in LDHA-silencing cancer cells. The recruitment of TAMs and the secretion of CCL2 were dramatically reduced after LDHA was knocked down in vitro and in vivo. Taken together, LDHA mediates a vicious cycle of mutual promotion between BCSCs plasticity and TAMs infiltration, which may provide an effective treatment strategy by targeting LDHA for breast cancer patients. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the role of miR-449b-5p in gastric cancer (GC) metabolism. Methods: Human GC samples and their corresponding normal tissues were used in this study. Cell survival ability was evaluated using a commercial MTT kit. Glucose uptake, lactate production and ATP content were assessed using commercial kits. The expression levels of miRNAs were assessed by stem-loop reverse transcription-polymerase chain reaction (RT-PCR). Results: MiR-449b-5p expression decreased in both GC tissues and cells. When the cells with low level of miR-449b-5p were transfected with miR-449b-5p mimics, glycolysis was inhibited (p < 0.05). Lactate dehydrogenase A (LDHA) was predicted as a target gene of miR-449b-5p and verified using luciferase reporter assay. MiR-449b-5p expression was up-regulated in GC cells (p < 0.05). Furthermore, miR- 449b-5p expression was related to long overall survival time in patients with GC. Conclusion: The findings demonstrate that miR-449b-5p reverses the glycolytic state of GC cells by targeting LDHA expression, and thus, it can potentially be developed for the treatment of gastric cancer. [ABSTRACT FROM AUTHOR]

Background: Myoglobin (MB) is increasingly recognized as a key player in cancer growth and metastasis. Low oxygen tensions, commonly associated with highly aggressive and recurrent cancers, have been shown to regulate its expression in several cancers such as lung, neck, prostate and breast cancer. However, it is not yet known whether it contributes to the growth and spread of brain cancers especially Glioblastoma multiforme (GBM). Methods: Here we investigate the expression of MB, and its correlation with the hypoxia markers carbonic anhydrase IX (CAIX) and lactate dehydrogenase A (LDHA), in human tissue microarrays of multiple organ tumors, brain tumors, and GBM tumors, and their respective cancer-adjacent normal tissues. Correlation between MB protein expression and tumor grade was also assessed. Results: We show that MB protein is expressed in a wide variety of cancers, benign tumors, cancer-adjacent normal tissues, hyperplastic tissue samples and normal brain tissue, and low oxygen tensions modulate MB protein expression in different brain cancers, including GBM. Enhanced nuclear LDHA immune-reactivity in GBM was also observed. Finally, we report for the first time a positive correlation between MB expression and brain tumor grade. Conclusion: Our data suggest that hypoxia regulate MB expression in different brain cancers (including GBM) and that its expression is associated with a more aggressive phenotype as indicated by the positive correlation with the brain tumor grade. Additionally, a role for nuclear LDHA in promoting aggressive tumor phenotype is also suggested based on enhanced nuclear expression which was observed only in GBM. [ABSTRACT FROM AUTHOR]

Background and aim: We previously identified forkhead box (FOX) O4 mRNA as a predictor in gastric cancer (GC). However, the underlying mechanism has yet to be elucidated. We aimed to illustrate the mechanism by which FOXO4 regulated glycolysis under hypoxia in GC. Methods: FOXO4 protein expression was investigated by immunohistochemical staining of 252 GC and their normal adjacent tissues. We restored or silenced FOXO4 expression in GC cell lines to explore the underlying mechanisms. Results: FOXO4 was downregulated in GC. Loss of FOXO4 expression was validated in univariate and multivariate survival analysis as an independent prognostic predictor for overall survival (P < 0.05) and disease‐free survival (P<0.05). Restored FOXO4 expression significantly impaired the glycolysis rate in GC cells, while silencing FOXO4 expression enhanced glycolysis rate. FOXO4 expression was inversely associated with maximum standardized uptake value in mice models and patient samples. Mechanistically, FOXO4 bound to the glycolytic enzyme lactate dehydrogenase (LDH)A promoter and inactivated its activity in a dose‐dependent manner (P < 0.05). Finally, we determined that FOXO4 was a transcriptional target of hypoxia‐inducible factor (HIF) ‐1α, which is central in response to hypoxia. Conclusions: Our data suggested that FOXO4 plays a key role in the regulation of glycolysis in GC, and disrupting the HIF‐1α‐FOXO4‐LDHA axis might be a promising therapeutic strategy for GC. [ABSTRACT FROM AUTHOR]

SET domain bifurcated 1 (SETDB1), a pivotal histone lysine methyltransferase, is transported to the cytoplasm via a chromosome region maintenance 1 (CMR1)‑dependent pathway, contributing to non‑histone methylation. However, the function and underlying mechanism of cytoplasmic SETDB1 in breast cancer remain elusive. In the present study, immunohistochemistry revealed that elevated cytoplasmic SETDB1 was correlated with lymph node metastasis and more aggressive breast cancer subtypes. Functionally, wound healing and Transwell assays showed that cytoplasmic SETDB1 is key for cell migration and invasion, as well as induction of epithelial‑mesenchymal transition (EMT), which was reversed by leptomycin B (LMB, a CMR1 inhibitor) treatment. Furthermore, RNA‑seq and metabolite detection revealed that cytoplasmic SETDB1 was associated with metabolism pathway and elevated levels of metabolites involved in the Warburg effect, including glucose, pyruvate, lactate and ATP. Immunoblotting and reverse transcription‑quantitative PCR verified that elevation of cytoplasmic SETDB1 contributed to elevation of c‑MYC expression and subsequent upregulation of lactate dehydrogenase A (LDHA) expression. Notably, gain‑ and loss‑of‑function approaches revealed that LDHA overexpression in T47D cells enhanced migration and invasion by inducing EMT, while its depletion in SETDB1‑overexpressing MCF7 cells reversed SETDB1‑induced migration and invasion, as well as the Warburg effect and EMT. In conclusion, subcellular localization of cytoplasmic SETDB1 may be a pivotal factor in breast cancer progression. The present study offers valuable insight into the novel functions and mechanisms of cytoplasmic SETDB1.

Lactate dehydrogenase A (LDHA) mediates interconversion of pyruvate and lactate, and increased lactate turnover is exhibited by malignant and infected immune cells. Hypoxic lung granuloma in Mycobacterium tuberculosis-infected animals present elevated levels of Ldha and lactate. Such alterations in the metabolic milieu could influence the outcome of host-M. tuberculosis interactions. Given the central role of LDHA for tumorigenicity, targeting lactate metabolism is a promising approach for cancer therapy. Here, we sought to determine the importance of LDHA for tuberculosis (TB) disease progression and its potential as a target for host-directed therapy. To this end, we orally administered FX11, a known small-molecule NADH-competitive LDHA inhibitor, to M. tuberculosis-infected C57BL/6J mice and Nos2−/− mice with hypoxic necrotizing lung TB lesions. FX11 did not inhibit M. tuberculosis growth in aerobic/hypoxic liquid culture, but modestly reduced the pulmonary bacterial burden in C57BL/6J mice. Intriguingly, FX11 administration limited M. tuberculosis replication and onset of necrotic lung lesions in Nos2−/− mice. In this model, isoniazid (INH) monotherapy has been known to exhibit biphasic killing kinetics owing to the probable selection of an INH-tolerant bacterial subpopulation. However, adjunct FX11 treatment corrected this adverse effect and resulted in sustained bactericidal activity of INH against M. tuberculosis. As a limitation, LDHA inhibition as an underlying cause of FX11-mediated effect could not be established as the on-target effect of FX11 in vivo was unconfirmed. Nevertheless, this proof-of-concept study encourages further investigation on the underlying mechanisms of LDHA inhibition and its significance in TB pathogenesis.

Background/Aims: Lactate is one of the products of glycolysis and is a hallmark of the Warburg effect. Glycolysis is found in tumor as well as immune cells. However, the effects of lactate on the function of tumor-infiltrating T cells (TILs) are rarely reported. Methods: In the present study, we investigated lactate and other glycolysis-related metabolites within TILs of human gastric cancer (GC). Lactate concentration was determined by liquid chromatography–mass spectrometry. The functional effects and clinical relevance of excessive lactate on T cells were investigated in clinical samples, and the mechanism of increased lactate was explored. Results: Lactate was significantly increased in GC TILs and related to decreased T helper (Th)1 cells and cytotoxic T lymphocytes (CTLs). Increased lactate within GC TILs was positively correlated with increased lactate dehydrogenase A (LDH)A. Expression of LDHA in GC TILs was also negatively correlated with percentages of Th1 cells and CTLs. Decreased miR-34a expression in GC TILs was responsible for increased expression of LDHA. A hypoxic tumor environment was responsible for decreased miR-34a and lactate-induced impaired immune function. Conclusion: We found that hypoxia decreases miR-34a expression and lose miR-34a regulation on LDHA, thus increasing lactate level within GC TILs and impairing immune function in GC.

The high expression of metabolic enzymes, including glutaminase (GA) and lactate dehydrogenase A (LDHA), which contribute to bioenergetics and biosynthesis of mammalian cells, has been identified in a variety of cancer types. The current study indicated intratumoral heterogeneity with respect to protein expression of the metabolic enzymes in colorectal cancer (CRC). GA protein expression was determined using immunohistochemistry in 98 cases of surgically resected T3 CRC. A total of 75 cases (74%) exhibited moderate to strong immunopositivity of GA based on whole-section examination. A significant correlation was demonstrated between GA expression and clinicopathological features, including histological type and tumor budding in a patient population. Detailed histological analysis revealed the upregulation of GA protein expression at the invasive margin, including tumor budding of CRC tissues. Semi-quantitative examination revealed a significant difference in immunoexpression level of GA between the invasive margin and central CRC. However, LDHA expression exhibited an opposite pattern, with expression elevated at the center and significantly decreased at the tumors invasive margin. Immunohistochemical expression of another glycolytic enzyme hexokinase II was equivalent in both regions. Furthermore, gene silencing of GLS1, which encodes GA protein, and GA inhibitor treatment significantly inhibited cell growth of CRC cell lines. Therefore, the results of the present study demonstrated that the alteration in GA and LDHA expression is more prominent at the invasive margin, which involves tumor budding in CRC. [ABSTRACT FROM AUTHOR]

The pathogenesis of colorectal cancer is a multifactorial process. Dysbiosis and the overexpression of COX-2 and LDHA are important effectors in the initiation and development of the disease through chromosomal instability, PGE2 biosynthesis, and induction of the Warburg effect, respectively. Herein, we report the in vitro testing of some new quinoxalinone and quinazolinone Schiff’s bases as: antibacterial, COX-2 and LDHA inhibitors, and anticolorectal agents on HCT-116 and LoVo cells. Moreover, molecular docking and SAR analyses were performed to identify the structural features contributing to the biological activities. Among the synthesized molecules, the most active cytotoxic agent, (6d) was also a COX-2 inhibitor. In silico ADMET studies predicted that (6d) would have high Caco-2 permeability, and %HIA (99.58%), with low BBB permeability, zero hepatotoxicity, and zero risk of sudden cardiac arrest, or mutagenicity. Further, (6d) is not a potential P-gp substrate, instead, it is a possible P-gpI and II inhibitor, therefore, it can prevent or reverse the multidrug resistance of the anticancer drugs. Collectively, (6d) can be considered as a promising lead suitable for further optimization to develop anti-CRC agents or glycoproteins inhibitors.

Human lactate dehydrogenase A (LDHA) plays a critical role in the glycolytic process, making the enzyme an ideal of anti-cancer drug target. Herein, we report the discovery of novel potent LDHA inhibitors by screening an in-house library. The hit-to-lead modification enabled us to identify compound 24c , which inhibited LDHA activity with an EC 50 value of 90 nM, and reduced MiaPaCa-2 cancer cell proliferation with an IC 50 value of 2.1 μM. In line with the in vitro anticancer activity, 24c suppressed the tumor growth at a dose of 10 mg/kg in a MiaPaCa-2 cells xenograft model, but with little effect to the mice weight. Moreover, 24c strongly inhibited MiaPaCa-2 cell colonies formation, induced MiaPaCa-2 cell apoptosis, and arrested MiaPaCa-2 cell cycle at G2 phase. In addition, the mitochondrial bioenergetics analysis suggested that 24c could reprogram cancer cell metabolic pathways from glycolysis to oxidation phosphorylation, which verified by decreasing the extracellular acidification rates and lactate formation, and increasing oxygen consumption rate in cancer cell. All these results indicate 24c is a promising metabolic modulator for the anticancer drug development. Compound 24c exhibited a potent biochemical potency, and in vitro and in vivo anticancer activity. Image 1 • Compound 24c inhibited LDHA with an EC 50 value of 90 nM. • Compound 24c reduced MiaPaCa-2 cell proliferation with an IC 50 value of 2.1 μM. • Compound 24c suppressed tumor growth in a xenograft model. [ABSTRACT FROM AUTHOR]

Triple negative breast cancer (TNBC) is one of the most aggressive types of breast cancer and has a poor prognosis. Therefore, the development of novel drugs and understanding the molecular mechanisms that may contribute to the initiation and development of TNBC are urgently required. Chidamide, a histone deacetylase inhibitor, has been reported as possessing anti-cancer properties in several cancers, however, the function of chidamide in TNBC remains to be elucidated. The present study revealed that chidamide inhibited the proliferation, colony formation and migration of TNBC cells. Experiments investigating the underlying mechanism revealed that chidamide upregulated the expression of microRNA (miR)-33a-5p in TNBC cells via RT-qPCR. Luciferase reporter assay demonstrated that miR-33a-5p was bound to the 3′-untranslated region of lactate dehydrogenase A (LDHA) and decreased the expression of LDHA in TNBC cells. In addition, chidamide suppressed the expression of LDHA and significantly decreased the glycolysis of TNBC cells. Collectively, the results of the present study demonstrated that chidamide reprogramed glucose metabolism, partially by targeting the miR-33a-5p/LDHA pathway, in TNBC. These findings indicate that chidamide may be a promising novel drug in the treatment of patients with TNBC. [ABSTRACT FROM AUTHOR]

Background: Trimethylation of histones has been extensively studied, where histone methyltransferases catalyze the transfer of methyl groups from S-adenosyl methionine. Thus far, there have been no researches on the trimethylation of non-histone proteins. The precise mechanisms by which trimethylation affects cell progress and the related protein functions remain unclear. Purpose: The objective of this study was to identify the Lys-trimethylated proteins in kidney-derived cells and tissues, as well as to better understand the mechanisms underlying Lys-trimethylation-mediated cell metabolism. Methods: The levels of Lys-trimethylation in kidney-derived cells and tissues were assayed by Western blotting. Additionally, high-resolution mass spectrometry was used to analyze kidney-derived cells and tissues, and the eukaryotic expression vectors that led to the mutations of lysine were constructed and transfected into HEK293T cells. The LDHA activity of HEK293T cells was detected under conditions of Lys-trimethylation inhibition, and the proliferation of HEK293T cells was measured using EdU and Western blotting analyses. Results: The different proteins in kidney-derived cells and tissues showed different levels of Lys-trimethylation. In particular, lactate dehydrogenase A (LDHA) was Lys-trimethylated on lysine (K5). Inhibition of the Lys-trimethylation in LDHA increased the LDH activity of HEK293T cells and upregulated their proliferation. Conclusion: We suggested that LDHA affects the metabolism and proliferation of cells via a Lys-trimethylation-mediated mechanism; Lys-trimethylation might be a potential target for therapeutic research or used as a prognostic and treatment biomarker of several diseases. [ABSTRACT FROM AUTHOR]

Objective To observe the expression changes of lactate dehydrogenase A(LDH-A) in gastric cancer cells and to explore the effect of silencing LDH-A expression on epithelial mesenchymal transformation(EMT) in gastric cancer cells. Methods The gastric cancer cell line OCUM-1 and normal gastric mucosal epithelial cell line RGM-1 were cultured in vitro,the relative expression of LDH-A mRNA in cells was detected by qRT-PCR,the expression of LDH-A protein in cells was detected by Western blotting. OCUM-1 cells were randomly divided into 3 groups,LDH-A siRNA group was transfected with LDH-A siRNA sequence using Lipfoctamine2000 liposome transfection reagent,the transfection control group was transfected with LDH-A siRNANC sequence,and the blank control group was only added with the culture medium. After 48-hour transfection,the cells of each group were collected and the morphological changes of gastric cancer cells were observed under microscope,the expression of E-cadherin,Cytokeratin,N-cadherin,Snail,β-catenin,and Vimentin was detected by Western blotting. Results The mRNA and protein expression of LDH-A in the OCUM-1 cells was higher than that in RGM-1 cells(both P<0. 05). The mRNA and protein expression of LDH-A in the LDH-A siRNA group was lower than that in the transfection control group and blank control group(all P<0. 05). Under microscopy,the cells in the LDH-A siRNA group were closely arranged,and the cell adhesion increased,showing the characteristics of epithelial cells.The protein expression levels of E-cadherin and Cytokeratin in the LDH-A siRNA group were higher than those in the transfection control group and blank control group,the protein expression levels of N-cadherin,Snail,β-catenin,and Vimentin in the LDH-A siRNA group were lower than those in the transfection control group and blank control group(all P<0. 05).Conclusion The expression of LDH-A increases in the gastric cancer cells,and silencing LDH-A expression can up-regulate the expression of epithelial characteristic protein,down-regulate the expression of stromal characteristic protein in gastric cancer cells,and thus inhibit the EMT process of gastric cancer cells. [ABSTRACT FROM AUTHOR]

Extensive growth of cancer in humans is a major cause of death. Numerous studies are being conducted to improve the early diagnosis, prevention, and treatment of cancer. Recent technological advancements in medical science and research indicate molecular target therapy holds much promise in cancer treatment. In the past, therapeutic and diagnostic targeting of non-glycolytic and glycolytic enzymes in cancer have been successful, and discoveries of biomarker enzymes in cancer hold promise for therapeutic treatments. In this review, we discuss the roles of several cancer-associated enzymes that could potentially act as therapeutic targets, and place special focus on non-glycolytic and glycolytic enzymes. This review indicates that the targeting of metabolic signaling offers a promising means of developing novel anti-cancer therapies. [ABSTRACT FROM AUTHOR]

Tumor suppressor p53 is a master regulator of apoptosis and plays key roles in cell cycle checkpoints. p53 responds to metabolic changes and alters metabolism through several mechanisms in cancer. Lactate dehydrogenase A (LDHA), a key enzyme in glycolysis, is highly expressed in a variety of tumors and catalyzes pyruvate to lactate. In the present study, we first analyzed the association and clinical significance of p53 and LDHA in breast cancer expressing wild‐type p53 (wt‐p53) and found that LDHA mRNA levels are negatively correlated with wt‐p53 but not with mutation p53 mRNA levels, and low p53 and high LDHA expression are significantly associated with poor overall survival rates. Furthermore, p53 negatively regulates LDHA expression by directly binding its promoter region. Moreover, a series of LDHA gain‐of‐function and rescore experiments were carried out in breast cancer MCF7 cells expressing endogenous wt‐p53, showing that ectopic expression of p53 decreases aerobic glycolysis, cell proliferation, migration, invasion and tumor formation of breast cancer cells and that restoration of the expression of LDHA in p53‐overexpressing cells could abolish the suppressive effect of p53 on aerobic glycolysis and other malignant phenotypes. In conclusion, our findings showed that repression of LDHA induced by wt‐p53 blocks tumor growth and invasion through downregulation of aerobic glycolysis in breast cancer, providing new insights into the mechanism by which p53 contributes to the development and progression of breast cancer. In the present study, we analyzed the association and clinical significance of wt‐p53 and LDHA expression in breast cancer with wt‐p53 expression and explored the mechanism of p53 regulation of LDHA at the transcription level. Furthermore, we carried out rescue experiments to identify the functional role and molecular mechanism of wt‐p53 and LDHA in breast cancer in vitro and in vivo. In summary, our findings show that p53 can directly regulate the expression of LDHA at the transcriptional level to control aerobic glycolysis, cell growth and invasion in breast cancer. [ABSTRACT FROM AUTHOR]

Identification of cues originating from skeletal muscle that govern bone formation is essential for understanding the crosstalk between muscle and bone and for developing therapies for degenerative bone diseases. Here, we identified that skeletal muscle secreted multiple extracellular vesicles (Mu-EVs). These Mu-EVs traveled through the bloodstream to reach bone, where they were phagocytized by bone marrow mesenchymal stem/stromal cells (BMSCs). Mu-EVs promoted osteogenic differentiation of BMSCs and protected against disuse osteoporosis in mice. The quantity and bioactivity of Mu-EVs were tightly correlated with the function of skeletal muscle. Proteomic analysis revealed numerous proteins in Mu-EVs, some potentially regulating bone metabolism, especially glycolysis. Subsequent investigations indicated that Mu-EVs promoted the glycolysis of BMSCs by delivering lactate dehydrogenase A into these cells. In summary, these findings reveal that Mu-EVs play a vital role in BMSC metabolism regulation and bone formation stimulation, offering a promising approach for treating disuse osteoporosis. [Display omitted] • Skeletal muscle secretes Mu-EVs, which can travel via blood vessels to bone • Supplementation with Mu-EVs alleviates disuse osteoporosis after muscle atrophy • Mu-EVs promote osteogenic differentiation of BMSCs by enhancing glycolysis • Glycolic profiles transported by Mu-EVs function as non-canonical myokines In their study, Ma et al. demonstrate that skeletal muscle secretes abundant extracellular vesicles (Mu-EVs). These Mu-EVs promote glycolysis in BMSCs by delivering glycolic profiles to enhance bone formation. The quantity and bioactivity of Mu-EVs are found to correlate with skeletal muscle function. Importantly, supplementation with Mu-EVs is shown to alleviate disuse osteoporosis following muscle atrophy, suggesting a potential therapeutic strategy. [ABSTRACT FROM AUTHOR]

Spatholobus suberectus (SS) is an excellent functional and medicinal food source of dietary procyanidins, which have numerous health benefits. Ten procyanidin fractions with different polymerization degrees were prepared from SS. For the first time, trimers to 11-mers were detected in SS extracts, and their compositions were elucidated through thiolysis, ESI-MS and MALDI-TOF-MS analyses. The results determined that the mean polymerization degree (mDP) of the crude SS procyanidins was 5.2 and that the mass distribution of the monomer and the oligomers (mDP of 1.0–5.7) was 70.4%, whereas that of the polymers (mDP of 6.2–11.8) was 25.6%. Catechin and epicatechin were the main monomeric units with minor quantities of epigallocatechin and gallocatechin. The observed interflavan linkages were both A-type (minor type) and B-type (major type). The fractions enriched in the monomer and oligomers showed the highest activities, including antioxidant activity and inhibitory activities on both the proliferation of MCF-7 breast cancer cells and lactate dehydrogenase A (LDH-A). These results suggested that the monomer- and oligomer-enriched procyanidin fractions from SS could undergo further development to become a beneficial source of antioxidants, LDH-A inhibitors, and potential inhibitors of breast cancer.

Osteoclasts are multinucleated, specializes bone-resorbing cells that are derived from the monocyte/macrophage lineage. Excessive resorbing activities of osteoclasts are involved in destructive bone diseases. The detailed mechanism of acidification at the bone adhesion surface during the bone resorption process of osteoclasts remains to be defined. During glycolysis, pyruvate proceeds to the tricarboxylic cycle under aerobic conditions and pyruvate is converted to lactate via lactate dehydrogenase A (LDHA) under anaerobic conditions. However, tumor cells produce ATP during aerobic glycolysis and large amounts of pyruvate are converted to lactate and H + by LDHA. Lactate and H + are excreted outside the cell, whereby they are involved in invasion of tumor cells due to the pH drop around the cell. In this study, we focused on aerobic glycolysis and investigated the production of lactate by LDHA in osteoclasts. Expression of LDHA and monocarboxylate transporter 4 (MCT4) was upregulated during osteoclast differentiation. Intracellular and extracellular lactate levels increased with upregulation of LDHA and MCT4, respectively. FX11 (an LDHA inhibitor) inhibited osteoclast differentiation and suppressed the bone-resorbing activity of osteoclasts. We propose that inhibition of LDHA may represent a novel therapeutic strategy for controlling excessive bone resorption in osteoporosis and rheumatoid arthritis., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2023 The Authors. Production and hosting by Elsevier B.V. All rights reserved.)

Human lactate dehydrogenase A (LDHA) is an anaerobic glycolytic enzyme involved in the inter-conversion of pyruvate to lactate. The level of LDHA in various types of cancer cells is found to be elevated and the dependence of cancer cells on anaerobic glycolysis is viewed as the reason for this elevation. Moreover, inhibition of LDHA activity has been shown to be effective in impairing the growth of tumors, making the LDHA as a potential target for cancer therapy. In this computational study, we have performed a pharmacophore based screening of approved drugs followed by a molecular docking based screening to find a few potential LDHA inhibitors. Molecular dynamics simulations have also been performed to examine the stability of the LDHA-drug complexes as obtained from the docking study. The result of the study showed that darunavir, moxalactam and eprosartan can bind to the active site of LDHA with high affinity in comparison to two known synthetic inhibitors of LDHA. The results of the molecular dynamics simulation showed that these drugs can bind stably with the enzyme through hydrogen bond and hydrophobic interactions. Hence, it is concluded that darunavir, moxalactam and eprosartan may be considered as potential inhibitors of LDHA and can be used for cancer therapy after proper validation of their effectiveness through in vitro, in vivo and clinical trials.Communicated by Ramaswamy H. Sarma.

Background/Aims: Lactate is one of the products of glycolysis and is a hallmark of the Warburg effect. Glycolysis is found in tumor as well as immune cells. However, the effects of lactate on the function of tumor-infiltrating T cells (TILs) are rarely reported. Methods: In the present study, we investigated lactate and other glycolysis-related metabolites within TILs of human gastric cancer (GC). Lactate concentration was determined by liquid chromatography–mass spectrometry. The functional effects and clinical relevance of excessive lactate on T cells were investigated in clinical samples, and the mechanism of increased lactate was explored. Results: Lactate was significantly increased in GC TILs and related to decreased T helper (Th)1 cells and cytotoxic T lymphocytes (CTLs). Increased lactate within GC TILs was positively correlated with increased lactate dehydrogenase A (LDH)A. Expression of LDHA in GC TILs was also negatively correlated with percentages of Th1 cells and CTLs. Decreased miR-34a expression in GC TILs was responsible for increased expression of LDHA. A hypoxic tumor environment was responsible for decreased miR-34a and lactate-induced impaired immune function. Conclusion: We found that hypoxia decreases miR-34a expression and lose miR-34a regulation on LDHA, thus increasing lactate level within GC TILs and impairing immune function in GC. [ABSTRACT FROM AUTHOR]

Glioblastoma multiforme (GBM) is a prevalent and aggressive disease, and the development of a novel therapy to better treat advanced GBM is urgently required. Lactate dehydrogenase A (LDHA), which functions as a key enzyme in transforming pyruvate into lactate, has attracted more attention in recent years due to its critical role in various types of advanced cancer. Previous data derived from the Oncomine database have shown that the expression of LDHA is higher in GBM tissues than that in corresponding normal control tissues. However, the association of LDHA levels with glioma clinical grades and the possible mechanisms of LDHA in GBM progression have not been investigated. The present study showed that there is a significant positive correlation between LDHA expression levels and tumor clinical stages. The knockdown of LDHA inhibited cell growth by inhibiting cell cycle progression and inducing apoptosis in glioma cell lines. Upon investigating the molecular mechanism, LDHA knockdown via siRNA treatment was associated with decreased cyclin D1 expression, increased cleavage of PARP, and altered B-cell lymphoma 2 and B-cell lymphoma 2-associated protein X expression. In addition, LDHA knockdown led to the marked downregulation of matrix metalloproteinase (MMP)-2, MMP-9, VE-Cadherin and vascular endothelial growth factor expression levels. Furthermore, knock down of LDHA enhanced the chemosensitivity of glioma cells to temozolomide (TMZ), a second-generation alkylating agent with activity against recurrent high-grade glioma. These findings support LDHA as a novel target for developing effective therapeutic strategies to treat GBM. [ABSTRACT FROM AUTHOR]

It has been well documented that changes in ion fluxes across cellular membranes is fundamental in maintaining cellular homeostasis. Dysregulation and/or malfunction of ion channels are critical events in the pathogenesis of diverse diseases, including cancers. In this study, we focused on the study of K + channels in hepatocellular carcinoma (HCC). By data mining TCGA cohort, the expression of 27 K + channels was investigated and KCNJ11 was identified as a key dysregulated K + channels in HCC. KCNJ11 was differentially expressed in HCC and predicted a poor prognosis in HCC patients. Inhibition of NFκB signaling suppressed KCNJ11 expression in HCC cells. Knockdown of KCNJ11 expression inhibited cell proliferation, promoted cell apoptosis, and reduced cell invasive capacity. Mechanistically, we found that KCNJ11 promotes tumor progression through interaction with LDHA and enhancing its enzymatic activity. Pharmacological inhibition of LDHA largely compromised the oncogenic function of KCNJ11 in cell proliferation, cell apoptosis, and cell invasion. Collectively, our data, as a proof of principle, demonstrate that KCNJ11 acts as an oncogene in HCC though forming a complex with LDHA and suggest that targeting KCNJ11 can be developed as a candidate tool to dampen HCC. [ABSTRACT FROM AUTHOR]

We have previously reported the toxicity of microcystin-LR (MC-LR) to the male reproductive system, which results in functional changes in mouse testes. In this study, mice were orally exposed to MC-LR at 1, 7.5, 15, or 30 μg/L daily for 180 days. We found an increase in germ cell apoptosis in the seminiferous tubules and low-quality sperm in the epididymis. A decrease in lactate dehydrogenase A (Ldha) expression in testes through high-throughput sequencing was observed. We validated that MC-LR disrupted lactate production in Sertoli cells by suppressing the expression of Ldha. Further studies identified that methyltransferase 3 (Mettl3) catalysed N6-methyladenosine (m6A) methylation of Ldha mRNA. Mettl3 was downregulated in Sertoli cells following exposure to MC-LR, decreasing m6A levels of Ldha. The stability of Ldha mRNA decreased when m6A levels of Ldha were inhibited. In conclusion, these results showed that MC-LR inhibits the expression of Ldha in an m6A-dependent manner, which might result in the apoptosis of spermatogenic cells and a decline in sperm quality. Our work provides a new perspective to understanding MC-LR-induced male infertility. [Display omitted] • The MC-LR-mediated disruption of energy metabolism plays a vital role in germ cell apoptosis. • MC-LR disrupts lactate production in Sertoli cells by suppressing the expression of Ldha. • MC-LR inhibits m6A modification of Ldha mRNA by suppressing Mettl3 expression, • Igf2bp3 enhances the stability of Ldha mRNA in an m6A-dependent manner. [ABSTRACT FROM AUTHOR]

Sufficient evidence has linked many different types of cancers and T2D through shared risk factors; however, the underlying mechanisms are not fully understood. α-Hydroxybutyrate (α-HB), a byproduct metabolite increased in diabetes and cancer, including colorectal cancer (CRC), triggers lactate dehydrogenase A (LDHA) nuclear translocation. Nuclear LDHA markedly extends NF-κB nuclear retention by interacting with phosphorylated p65, leading to an increase in TNF-α production, impaired insulin secretion and the exacerbation of azoxymethane (AOM)/dextran sodium sulfate (DSS)-induced CRC and high-fat diet (HFD)-induced type 2 diabetes. Furthermore, metformin interrupted this process by inhibiting the transcription of FOXM1 and c-MYC, the resultant downregulation of LDHA expression and α-HB-induced LDHA nuclear translocation. Thus, the results reveal the elevated α-HB level could be a novel shared risk factor of linking CRC, diabetes and the use of metformin treatment, as well as highlight the importance of preventing NF-κB activation for protecting against cancer and diabetes. • α-HB accelerates the development of colorectal cancer and type 2 diabetes. • α-HB prolongs the nuclear retention of NF-κB via LDHA. • Metformin inhibits nuclear LDHA-induced NF-κB nuclear retention. [ABSTRACT FROM AUTHOR]