The role of phosphoglycerate mutase 1 in tumor aerobic glycolysis and its potential therapeutic implications

Identification of Hypoxia-ALCAMhigh Macrophage- Exhausted T Cell Axis in Tumor Microenvironment Remodeling for Immunotherapy Resistance

Although hypoxia is known to be associated with immune resistance, the adaptability to hypoxia by different cell populations in the tumor microenvironment and the underlying mechanisms remain elusive. This knowledge gap has hindered the development of therapeutic strategies to overcome tumor immune resistance induced by hypoxia. Here, bulk, single-cell, and spatial transcriptomics are integrated to characterize hypoxia associated with immune escape during carcinogenesis and reveal a hypoxia-based intercellular communication hub consisting of malignant cells, ALCAMhigh macrophages, and exhausted CD8+ T cells around the tumor boundary. A hypoxic microenvironment promotes binding of HIF-1α complex is demonstrated to the ALCAM promoter therefore increasing its expression in macrophages, and the ALCAMhigh macrophages co-localize with exhausted CD8+ T cells in the tumor spatial microenvironment and promote T cell exhaustion. Preclinically, HIF-1ɑ inhibition reduces ALCAM expression in macrophages and exhausted CD8+ T cells and potentiates T cell antitumor function to enhance immunotherapy efficacy. This study reveals the systematic landscape of hypoxia at single-cell resolution and spatial architecture and highlights the effect of hypoxia on immunotherapy resistance through the ALCAMhigh macrophage-exhausted T cell axis, providing a novel immunotherapeutic strategy to overcome hypoxia-induced resistance in cancers.

Ethanolic extract from Sophora moorcroftiana inhibit cell proliferation and alter the mechanical properties of human cervical cancer

BACKGROUND

Cervical cancer is one of the most common gynecological malignancies. Previous studies have shown that the ethanol extract of Sophora moorcroftiana seeds (EESMS) possesses an antiproliferative effect on several tumors in vitro. Therefore, in this study, we assessed the impact of EESMS on human cervical carcinoma (HeLa) cell proliferation.

METHODS

The proliferation and apoptotic effects of HeLa cells treated with EESMS were evaluated using 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide assay, dual acridine orange/ethidium bromide double staining, flow cytometry, and western blotting. Single-cell level atomic force microscopy (AFM) was conducted to detect the mechanical properties of HeLa cells, and proteomics and bioinformatics methods were used to elucidate the molecular mechanisms of EESMS.

RESULTS

EESMS treatment inhibited HeLa cell proliferation by blocking the G0/G1 phase, increasing the expression of Caspase-3 and affecting its mechanical properties, and the EESMS indicated no significant inhibitory effect on mouse fibroblasts L929 cell line. In total, 218 differentially expressed proteins were identified using two-dimensional electrophoresis, and eight differentially expressed proteins were successfully identified using matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry. The differentially expressed proteins were involved in various cellular and biological processes.

CONCLUSION

This study provides a perspective on how cells change through biomechanics and a further theoretical foundation for the future application of Sophora moorcroftiana as a novel low-toxicity chemotherapy medication for treating human cervical cancer.

Sericin promotes chondrogenic proliferation and differentiation via glycolysis and Smad2/3 TGF-β signaling inductions and alleviates inflammation in three-dimensional models

Knee osteoarthritis is a chronic joint disease mainly characterized by cartilage degeneration. The treatment is challenging due to the lack of blood vessels and nerve supplies in cartilaginous tissue, causing a prominent limitation of regenerative capacity. Hence, we investigated the cellular promotional and anti-inflammatory effects of sericin, Bombyx mori-derived protein, on three-dimensional chondrogenic ATDC5 cell models. The results revealed that a high concentration of sericin promoted chondrogenic proliferation and differentiation and enhanced matrix production through the increment of glycosaminoglycans, COL2A1, COL X, and ALP expressions. SOX-9 and COL2A1 gene expressions were notably elevated in sericin treatment. The proteomic analysis demonstrated the upregulation of phosphoglycerate mutase 1 and triosephosphate isomerase, a glycolytic enzyme member, reflecting the proliferative enhancement of sericin. The differentiation capacity of sericin was indicated by the increased expressions of procollagen12a1, collagen10a1, rab1A, periostin, galectin-1, and collagen6a3 proteins. Sericin influenced the differentiation capacity via the TGF-β signaling pathway by upregulating Smad2 and Smad3 while downregulating Smad1, BMP2, and BMP4. Importantly, sericin exhibited an anti-inflammatory effect by reducing IL-1β, TNF-α, and MMP-1 expressions and accelerating COL2A1 production in the early inflammatory stage. In conclusion, sericin demonstrates potential in promoting chondrogenic proliferation and differentiation, enhancing cartilaginous matrix synthesis through glycolysis and TGF-β signaling pathways, and exhibiting anti-inflammatory properties.

MUC1-C integrates aerobic glycolysis with suppression of oxidative phosphorylation in triple-negative breast cancer stem cells

Activation of the MUC1-C protein promotes lineage plasticity, epigenetic reprogramming, and the cancer stem cell (CSC) state. The present studies performed on enriched populations of triple-negative breast cancer (TNBC) CSCs demonstrate that MUC1-C is essential for integrating activation of glycolytic pathway genes with self-renewal and tumorigenicity. MUC1-C further integrates the glycolytic pathway with suppression of mitochondrial DNA (mtDNA) genes encoding components of mitochondrial Complexes I-V. The repression of mtDNA genes is explained by MUC1-C-mediated (i) downregulation of the mitochondrial transcription factor A (TFAM) required for mtDNA transcription and (ii) induction of the mitochondrial transcription termination factor 3 (mTERF3). In support of pathogenesis that suppresses mitochondrial ROS production, targeting MUC1-C increases (i) mtDNA gene transcription, (ii) superoxide levels, and (iii) loss of self-renewal capacity. These findings and scRNA-seq analysis of CSC subpopulations indicate that MUC1-C regulates self-renewal and redox balance by integrating activation of glycolysis with suppression of oxidative phosphorylation.

The role of glycolytic metabolic pathways in cardiovascular disease and potential therapeutic approaches

Cardiovascular disease (CVD) is a major threat to human health, accounting for 46% of non-communicable disease deaths. Glycolysis is a conserved and rigorous biological process that breaks down glucose into pyruvate, and its primary function is to provide the body with the energy and intermediate products needed for life activities. The non-glycolytic actions of enzymes associated with the glycolytic pathway have long been found to be associated with the development of CVD, typically exemplified by metabolic remodeling in heart failure, which is a condition in which the heart exhibits a rapid adaptive response to hypoxic and hypoxic conditions, occurring early in the course of heart failure. It is mainly characterized by a decrease in oxidative phosphorylation and a rise in the glycolytic pathway, and the rise in glycolysis is considered a hallmark of metabolic remodeling. In addition to this, the glycolytic metabolic pathway is the main source of energy for cardiomyocytes during ischemia-reperfusion. Not only that, the auxiliary pathways of glycolysis, such as the polyol pathway, hexosamine pathway, and pentose phosphate pathway, are also closely related to CVD. Therefore, targeting glycolysis is very attractive for therapeutic intervention in CVD. However, the relationship between glycolytic pathway and CVD is very complex, and some preclinical studies have confirmed that targeting glycolysis does have a certain degree of efficacy, but its specific role in the development of CVD has yet to be explored. This article aims to summarize the current knowledge regarding the glycolytic pathway and its key enzymes (including hexokinase (HK), phosphoglucose isomerase (PGI), phosphofructokinase-1 (PFK1), aldolase (Aldolase), phosphoglycerate metatase (PGAM), enolase (ENO) pyruvate kinase (PKM) lactate dehydrogenase (LDH)) for their role in cardiovascular diseases (e.g., heart failure, myocardial infarction, atherosclerosis) and possible emerging therapeutic targets.

Single-cell landscape and spatial transcriptomic analysis reveals macrophage infiltration and glycolytic metabolism in kidney renal clear cell carcinoma

The present study investigates the clinical relevance of glycolytic factors, specifically PGAM1, in the tumor microenvironment of kidney renal clear cell carcinoma (KIRC). Despite the established role of glycolytic metabolism in cancer pathophysiology, the prognostic implications and key targets in KIRC remain elusive. We analyzed GEO and TCGA datasets to identify DEGs in KIRC and studied their relationship with immune gene expression, survival, tumor stage, gene mutations, and infiltrating immune cells. We explored Pgam1 gene expression in different kidney regions using spatial transcriptomics after mouse kidney injury analysis. Single-cell RNA-sequencing was used to assess the association of PGAM1 with immune cells. Findings were validated with tumor specimens from 60 KIRC patients, correlating PGAM1 expression with clinicopathological features and prognosis using bioinformatics and immunohistochemistry. We demonstrated the expression of central gene regulators in renal cancer in relation to genetic variants, deletions, and tumor microenvironment. Mutations in these hub genes were positively associated with distinct immune cells in six different immune datasets and played a crucial role in immune cell infiltration in KIRC. Single-cell RNA-sequencing revealed that elevated PGAM1 was associated with immune cell infiltration, specifically macrophages. Furthermore, pharmacogenomic analysis of renal cancer cell lines indicated that inactivation of PGAM1 was associated with increased sensitivity to specific small-molecule drugs. Altered PGAM1 in KIRC is associated with disease progression and immune microenvironment. It has diagnostic and prognostic implications, indicating its potential in precision medicine and drug screening.

Genetically engineered Lactobacillus paracasei rescues colonic angiotensin converting enzyme 2 (ACE2) and attenuates hypertension in female Ace2 knock out rats

Engineered gut microbiota represents a new frontier in medicine, in part serving as a vehicle for the delivery of therapeutic biologics to treat a range of host conditions. The gut microbiota plays a significant role in blood pressure regulation; thus, manipulation of gut microbiota is a promising avenue for hypertension treatment. In this study, we tested the potential of Lactobacillus paracasei, genetically engineered to produce and deliver human angiotensin converting enzyme 2 (Lacto-hACE2), to regulate blood pressure in a rat model of hypertension with genetic ablation of endogenous Ace2 (Ace2-/- and Ace2-/y). Our findings reveal a sex-specific reduction in blood pressure in female (Ace2-/-) but not male (Ace2-/y) rats following colonization with the Lacto-hACE2. This beneficial effect of lowering blood pressure was aligned with a specific reduction in colonic angiotensin II, but not renal angiotensin II, suggesting the importance of colonic Ace2 in the regulation of blood pressure. We conclude that this approach of targeting the colon with engineered bacteria for delivery of ACE2 represents a promising new paradigm in the development of antihypertensive therapeutics.

CircRNA PGAM1 Promotes the Migration and Invasion of Pancreatic Adenocarcinoma Cells by Activating the AKT/mTOR Signaling Pathway

Pancreatic adenocarcinoma (PAAD) is a lethal malignancy of the gastrointestinal tract. Circular RNA, an endogenous noncoding RNA, is considered a new regulatory molecule in tumorigenesis and development. Here, we aimed to investigate the role of circPGAM1 in PAAD. The PAAD cell line HPAC was transfected with OE-circPGAM1 to overexpress circPGAM1 and treated with AZD5363 to inhibit the AKT/mTOR pathway. Simultaneously, another PAAD cell line BxPC-3 was transfected with sh-circPGAM1 to silence circPGAM1. The GEPIA database was used to determine the expression of circPGAM1 in PAAD and its association with overall and disease-free survival. CircPGAM1 expression levels were determined in cell lines using reverse transcription-quantitative PCR. The cell counting kit-8, wound healing, and transwell assays were performed to determine cell migration and invasion. The protein expression levels of phosphorylated AKT and mTOR were determined using western blotting. CircPGAM1 was overexpressed in PAAD and related to poor prognosis. Silencing circPGAM1 inhibited migration and invasion of BxPC-3 cells, and overexpression of circPGAM1 showed the opposite effects. Overall, circPGAM1 promoted the migration and invasion of PAAD cells through the AKT/mTOR axis.

MicroRNA-324-3p inhibits osteosarcoma progression by suppressing PGAM1-mediated aerobic glycolysis

Osteosarcoma (OS) is the most common primary malignant neoplasm of the bone. Recent studies have indicated that the inhibitory effects of microRNA (miR)-324-3p could affect the development of numerous cancers. However, its biological roles and underlying mechanisms in OS progression remain unexplored. In this study, miR-324-3p expression was markedly reduced in OS cell lines and tissues. Functionally, miR-324-3p overexpression suppressed OS progression and was involved in the Warburg effect. Mechanistically, miR-324-3p negatively regulated phosphoglycerate mutase 1 (PGAM1) expression by targeting its 3'-UTR. Moreover, high expression of PGAM1 promoted OS progression and aerobic glycolysis, which were associated with inferior overall survival in patients with OS. Notably, the tumor suppressor functions of miR-324-3p were partially recovered by PGAM1 overexpression. In summary, the miR-324-3p/PGAM1 axis plays an important role in regulating OS progression by controlling the Warburg effect. Our results provide mechanistic insights into the function of miR-324-3p in glucose metabolism and subsequently on the progression of OS. Targeting the miR-324-3p/PGAM1 axis could be a promising molecular strategy for the treatment of OS.

Sumoylation-deficient phosphoglycerate mutase 2 impairs myogenic differentiation

Phosphoglycerate mutase 2 (PGAM2) is a critical glycolytic enzyme that is highly expressed in skeletal muscle. In humans, naturally occurring mutations in Phosphoglycerate mutase 2 have been etiologically linked to glycogen storage disease X (GSDX). Phosphoglycerate mutase 2 activity is regulated by several posttranslational modifications such as ubiquitination and acetylation. Here, we report that Phosphoglycerate mutase 2 activity is regulated by sumoylation-a covalent conjugation involved in a wide spectrum of cellular events. We found that Phosphoglycerate mutase 2 contains two primary SUMO acceptor sites, lysine (K)49 and K176, and that the mutation of either K to arginine (R) abolished Phosphoglycerate mutase 2 sumoylation. Given that K176 is more highly evolutionarily conserved across paralogs and orthologs than K49 is, we used the CRISPR-mediated homologous recombination technique in myogenic C2C12 cells to generate homozygous K176R knock-in cells (PGAM2^K176R/K176R). Compared with wild-type (WT) C2C12 cells, PGAM2^K176R/K176R C2C12 cells exhibited impaired myogenic differentiation, as indicated by decreased differentiation and fusion indexes. Furthermore, the results of glycolytic and mitochondrial stress assays with the XF96 Extracellular Flux analyzer revealed a reduced proton efflux rate (PER), glycolytic PER (glycoPER), extracellular acidification rate (ECAR), and oxygen consumption rate (OCR) in PGAM2^K176R/K176R C2C12 cells, both at baseline and in response to stress. Impaired mitochondrial function was also observed in PGAM2^K176R/K176R P19 cells, a carcinoma cell line. These findings indicate that the PGAM2-K176R mutation impaired glycolysis and mitochondrial function. Gene ontology term analysis of RNA sequencing data further revealed that several downregulated genes in PGAM2^K176R/K176R C2C12 cells were associated with muscle differentiation/development/contraction programs. Finally, PGAM2 with either of two naturally occurring missense mutations linked to GSDX, E89A (conversion of glutamic acid 89 to alanine) or R90W (conversion of arginine 90 to tryptophan), exhibited reduced Phosphoglycerate mutase 2 sumoylation. Thus, sumoylation is an important mechanism that mediates Phosphoglycerate mutase 2 activity and is potentially implicated in Phosphoglycerate mutase 2 mutation-linked disease in humans.

Correlation of Glucose Metabolism with Cancer and Intervention with Traditional Chinese Medicine

Cancer is a complex disease with several distinct characteristics, referred to as “cancer markers” one of which is metabolic reprogramming, which is a common feature that drives cancer progression. Over the last ten years, researchers have focused on the reprogramming of glucose metabolism in cancer. In cancer, the oxidative phosphorylation metabolic pathway is converted into the glycolytic pathway in order to meet the growth requirements of cancer cells, thereby creating a microenvironment that promotes cancer progression. The precise mechanism of glucose metabolism in cancer cells is still unknown, but it is thought to involve the aberrant levels of metabolic enzymes, the influence of the tumor microenvironment (TME), and the activation of tumor-promoting signaling pathways. It is suggested that glucose metabolism is strongly linked to cancer progression because it provides energy to cancer cells and interferes with antitumor drug pharmacodynamics. Therefore, it is critical to unravel the mechanism of glucose metabolism in tumors in order to gain a better understanding of tumorigenesis and to lay the groundwork for future research into the identification of novel diagnostic markers and therapeutic targets for cancer treatment. Traditional Chinese Medicine (TCM) has the characteristics of multiple targets, multiple components, and less toxic side effects and has unique advantages in tumor treatment. In recent years, researchers have found that a variety of Chinese medicine monomers and compound recipes play an antitumor role by interfering with the reprogramming of tumor metabolism. The underlying mechanisms of metabolism reprogramming of tumor cells and the role of TCM in regulating glucose metabolism are reviewed in this study, so as to provide a new idea for antitumor research in Chinese medicine.

Phosphoglycerate mutase 1 that is essential for glycolysis may act as a novel metabolic target for predicating poor prognosis for patients with gastric cancer

BACKGROUND

To identify a novel marker for gastric cancer, we examined the usefulness of phosphoglycerate mutase 1 (PGAM1) as a potential diagnostic marker using isobaric tags for relative and absolute quantitation (iTRAQ)-based quantitative proteomics and evaluated its clinical significance.

METHODS

Proteins from a discovery group of four paired gastric cancer tissues and adjacent gastric tissues were labeled with iTRAQ reagents and then identified and quantified using LC-MS/MS. The expression of PGAM1 was further validated in 139 gastric cancer patients using immunohistochemistry. Furthermore, the correlation of PGAM1 expression with clinical parameters was analyzed. Gene set enrichment analysis (GSEA) was performed to identify gene sets that were activated in PGAM1-overexpressing patients with gastric cancer.

RESULTS

PGAM1 was significantly overexpressed in most cancers but particularly so in gastric cancer, with a sensitivity of 82.01% (95% confidence interval [CI]: 75.5%-88.5%) and specificity of 79.13% (95% CI: 72.3%-86%). Its expression was significantly associated with histological grade II and III tumors (p = 0.033), lymph node metastasis (p = 0.031), and TNM III-IV staging (p = 0.025). The area under the receiver operating characteristic (ROC) curve for the detection of PGAM1 overexpression in gastric cancer was 0.718 (p < 0.01). Furthermore, GSEA revealed that several important pathways such as glycolysis pathway and immune pathways were significantly enriched in patients with gastric cancer with PGAM1 overexpression.

CONCLUSIONS

This study provided a sensitive method for detecting PGAM1, which may serve as a novel indicator for poor prognosis of gastric cancer, as well as a potent drug target for gastric cancer.

PGAM1 regulation of ASS1 contributes to the progression of breast cancer through the cAMP/AMPK/CEBPB pathway

Phosphoglycerate mutase 1 (PGAM1) is a crucial glycolytic enzyme, and its expression status has been confirmed to be associated with tumor progression and metastasis. However, the precise role and other biological functions of PGAM1 remain unclear. Here, we report that PGAM1 expression is upregulated and related to poor prognosis in patients with breast cancer (BC). Functional experiments showed that knockdown of PGAM1 could suppress the proliferation, invasion, migration, and epithelial–mesenchymal transition of BC cells. Through RNA sequencing, we found that argininosuccinate synthase 1 (ASS1) expression was markedly upregulated in BC cells following PGAM1 knockdown, and it is required to suppress the malignant biological behavior of BC cells. Importantly, we demonstrated that PGAM1 negatively regulates ASS1 expression through the cAMP/AMPK/CEBPB axis. In vivo experiments further validated that PGAM1 promoted tumor growth in BC by altering ASS1 expression. Finally, immunohistochemical analysis showed that downregulated ASS1 levels were associated with PGAM1 expression and poor prognosis in patients with BC. Our study provides new insight into the regulatory mechanism of PGAM1‐mediated BC progression that might shed new light on potential targets and combination therapeutic strategies for BC treatment.

Differing impact of phosphoglycerate mutase 1-deficiency on brown and white adipose tissue

Brown adipose tissue (BAT) is a metabolically active organ that contributes to the thermogenic response to cold exposure. In addition, other thermogenic cells termed beige adipocytes are generated in white adipose tissue (WAT) by cold exposure. Although activation of brown/beige adipose tissue is associated with mobilization of both glucose and lipids, few studies have focused on the role of glycolytic enzymes in regulating adipose tissue function. We generated mouse models with specific deletion of the glycolytic enzyme phosphoglycerate mutase 1 (PGAM1) from adipose tissue. Deletion of Pgam1 from both BAT and WAT promoted whitening of BAT with beiging of visceral WAT, whereas deletion of Pgam1 from BAT alone led to whitening of BAT without beiging of WAT. Our results demonstrate a potential role of glycolytic enzymes in beiging of visceral WAT and suggest that PGAM1 would be a novel therapeutic target in obesity and diabetes.

•

Pgam1 deletion leads to whitening of brown adipose tissue

•

Pgam1 deletion promotes beiging of visceral white adipose tissue (WAT)

•

Pgam1 deletion-induced beiging is associated with increased levels of amino acids

The tetrameric structure of Plasmodium falciparum phosphoglycerate mutase is critical for optimal enzymatic activity

The glycolytic enzyme phosphoglycerate mutase (PGM) is of utmost importance for overall cellular metabolism and has emerged as a novel therapeutic target in cancer cells. This enzyme is also conserved in the rapidly proliferating malarial parasite Plasmodium falciparum, which have a similar metabolic framework as cancer cells and rely on glycolysis as the sole energy-yielding process during intraerythrocytic development. There is no redundancy among the annotated PGM enzymes in Plasmodium, and PfPGM1 is absolutely required for the parasite survival as evidenced by conditional knockdown in our study. A detailed comparison of PfPGM1 with its counterparts followed by in-depth structure-function analysis revealed unique attributes of this parasitic protein. Here, we report for the first time the importance of oligomerization for the optimal functioning of the enzyme in vivo, as earlier studies in eukaryotes only focused on the effects in vitro. We show that single point mutation of the amino acid residue W68 led to complete loss of tetramerization and diminished catalytic activity in vitro. Additionally, ectopic expression of the WT PfPGM1 protein enhanced parasite growth, whereas the monomeric form of PfPGM1 failed to provide growth advantage. Furthermore, mutation of the evolutionarily conserved residue K100 led to a drastic reduction in enzymatic activity. The indispensable nature of this parasite enzyme highlights the potential of PfPGM1 as a therapeutic target against malaria, and targeting the interfacial residues critical for oligomerization can serve as a focal point for promising drug development strategies that may not be restricted to malaria only.

Metabolic shift to serine biosynthesis through 3-PG accumulation and PHGDH induction promotes tumor growth in pancreatic cancer

Cancer cells craftily adapt their energy metabolism to their microenvironment. Nutrient deprivation due to hypovascularity and fibrosis is a major characteristic of pancreatic ductal adenocarcinoma (PDAC); thus, PDAC cells must produce energy intrinsically. However, the enhancement of energy production via activating Kras mutations is insufficient to explain the metabolic rewiring of PDAC cells. Here, we investigated the molecular mechanism underlying the metabolic shift in PDAC cells under serine starvation. Amino acid analysis revealed that the concentrations of all essential amino acids and most nonessential amino acids were decreased in the blood of PDAC patients. In addition, the plasma serine concentration was significantly higher in PDAC patients with PHGDH-high tumors than in those with PHGDH-low tumors. Although the growth and tumorigenesis of PK-59 cells with PHGDH promoter hypermethylation were significantly decreased by serine starvation, these activities were maintained in PDAC cell lines with PHGDH promoter hypomethylation by serine biosynthesis through PHGDH induction. In fact, DNA methylation analysis by pyrosequencing revealed that the methylation status of the PHGDH promoter was inversely correlated with the PHGDH expression level in human PDAC tissues. In addition to PHGDH induction by serine starvation, PDAC cells showed enhanced serine biosynthesis under serine starvation through 3-PG accumulation via PGAM1 knockdown, resulting in enhanced PDAC cell growth and tumor growth. However, PHGDH knockdown efficiently suppressed PDAC cell growth and tumor growth under serine starvation. These findings provide evidence that targeting the serine biosynthesis pathway by inhibiting PHGDH is a potent therapeutic approach to eliminate PDAC cells in nutrient-deprived microenvironments.

Comparative proteomics reveals Cryptosporidium parvum manipulation of the host cell molecular expression and immune response

Cryptosporidium is a life-threating protozoan parasite belonging to the phylum Apicomplexa, which mainly causes gastroenteritis in a variety of vertebrate hosts. Currently, there is a re-emergence of Cryptosporidium infection; however, no fully effective drug or vaccine is available to treat Cryptosporidiosis. In the present study, to better understand the detailed interaction between the host and Cryptosporidium parvum, a large-scale label-free proteomics study was conducted to characterize the changes to the proteome induced by C. parvum infection. Among 4406 proteins identified, 121 proteins were identified as differentially abundant (> 1.5-fold cutoff, P < 0.05) in C. parvum infected HCT-8 cells compared with uninfected cells. Among them, 67 proteins were upregulated, and 54 proteins were downregulated at 36 h post infection. Analysis of the differentially abundant proteins revealed an interferon-centered immune response of the host cells against C. parvum infection and extensive inhibition of metabolism-related enzymes in the host cells caused by infection. Several proteins were further verified using quantitative real-time reverse transcription polymerase chain reaction and western blotting. This systematic analysis of the proteomics of C. parvum-infected HCT-8 cells identified a wide range of functional proteins that participate in host anti-parasite immunity or act as potential targets during infection, providing new insights into the molecular mechanism of C. parvum infection.

Cryptosporidium parvum is an emerging zoonotic pathogen transmitted via the fecal–oral route, and is considered a leading cause of moderate-to-severe diarrheal disease in young children in resource limited areas. After infection, C. parvum parasitizes intestinal epithelial cells and evokes an inflammatory immune response, leading to severe damage of the intestinal mucosa. The infection can be lethal to immunosuppressed individuals. However, no fully effective drug or vaccine is available for cryptosporidiosis, and the pathogenesis and immune mechanisms during C. parvum infection are obscure. Thus, an in-depth understanding of host-parasite interaction is needed. Hence, we established a C. parvum-infected HCT-8 cell model and performed comparative quantitative proteomic analyses to profile global host-parasite interactions and determine the molecular mechanisms that are activated during infection, aiming to offer new insights into the treatment of Cryptosporidium.

A short review on cross-link between pyruvate kinase (PKM2) and Glioblastoma Multiforme

Pyruvate kinase (PK) catalyzes the last irreversible reaction of glycolysis pathway, generating pyruvate and ATP, from Phosphoenol Pyruvate (PEP) and ADP precursors. In mammals, four different tissue-specific isoforms (M1, M2, L and R) of PK exist, which are translated from two genes (PKL and PKR). PKM2 is the highly expressed isoform of PK in cancers, which regulates the aerobic glycolysis via reprogramming cancer cell's metabolic pathways to provide an anabolic advantage to the tumor cells. In addition to the established role of PKM2 in aerobic glycolysis of multiple cancer types, various recent findings have highlighted the non-metabolic functions of PKM2 in brain tumor development. Nuclear PKM2 acts as a co-activator and directly regulates gene transcription. PKM2 dependent transactivation of various oncogenic genes is instrumental in the progression and aggressiveness of Glioblastoma Multiforme (GBM). Also, PKM2 acts as a protein kinase in histone modification which regulates gene expression and tumorigenesis. Ongoing research has explored novel regulatory mechanisms of PKM2 and its association in GBM progression. This review enlists and summarizes the metabolic and non-metabolic roles of PKM2 at the cellular level, and its regulatory function highlights the importance of the nuclear functions of PKM2 in GBM progression, and an emerging role of PKM2 as novel cancer therapeutics.

In Silico Drug Screening Analysis against the Overexpression of PGAM1 Gene in Different Cancer Treatments

Phosphoglycerate mutase 1 (PGAM1) is considered as a novel target for multiple types of cancer drugs for the upregulation in tumor, cell prefoliation, and cell migration. During aerobic glycolysis, PGAM1 plays a critical role in cancer cell metabolism by catalyzing the conversion of 3-phosphoglycerate (3PG) to 2-phosphoglycerate (2PG). In this computational-based study, the molecular docking approach was used with the best binding active sites of PGAM1 to screen 5,000 Chinese medicinal phytochemical library. The docking results were three ligands with docking score, RMSD-refine, and residues. Docking scores were -16.57, -15.22, and -15.74. RMSD values were 0.87, 2.40, and 0.98, and binding site residues were Arg 191, Arg 191, Arg 116, Arg 90, Arg 10, and Tyr 92. The best compounds were subjected to ADMETsar, ProTox-2 server, and Molinspiration analysis to evaluate the toxicological and drug likeliness potential of such selected compounds. The UCSF-Chimera tool was used to visualize the results, which shows that the three medicinal compounds named N-Nitrosohexamethyleneimine, Subtrifloralactone-K, and Kanzonol-N in chain-A were successfully binding with the active pockets of PGAM1. The study might facilitate identifying the hit molecules that could be beneficial in the development of antidrugs against various types of cancer treatment. These hit phytochemicals could be beneficial for further investigation of a novel target for cancer.

Design, synthesis, and biological evaluation of 1,3,6,7-tetrahydroxyxanthone derivatives as phosphoglycerate mutase 1 inhibitors

Phosphoglycerate mutase 1 (PGAM1) is a promising target for cancer treatment. Herein, we found that α-mangostin and γ-mangostin exhibited moderate PGAM1 inhibitory activities, with IC₅₀ of 7.2 μM and 1.2 µM, respectively. Based on α-mangostin, a series of 1,3,6,7-tetrahydroxyxanthone derivatives were designed, synthesized and evaluated in vitro for PGAM1 inhibition. The significant structure-activity relationships (SAR) and a fresh binding mode of this kind of new compounds were also clearly described. This study provides valuable information for further optimization of PGAM1 inhibitors with 1,3,6,7-tetrahydroxyxanthone backbone or de novo design of novel inhibitor.

Signaling, metabolism, and cancer: An important relationship for therapeutic intervention

In cancerous cells, significant changes occur in the activity of signaling pathways affecting a wide range of cellular activities ranging from growth and proliferation to apoptosis, invasiveness, and metastasis. Extensive changes also happen with respect to the metabolism of a cancerous cell encompassing a wide range of functions that include: nutrient acquisition, biosynthesis of macromolecules, and energy generation. These changes are important and some therapeutic approaches for treating cancers have focused on targeting the metabolism of cancerous cells. Oncogenes and tumor suppressor genes have a significant effect on the metabolism of cells. There appears to be a close interaction between metabolism and the signaling pathways in a cancerous cell, in which the interaction provides the metabolic needs of a cancerous cell for uncontrolled proliferation, resistance to apoptosis, and metastasis. In this review, we have reviewed the latest findings in this regard and briefly review the most recent research findings regarding targeting the metabolism of cancer cells as a therapeutic approach for treatment of cancer.

A New Twist in Protein Kinase B/Akt Signaling: Role of Altered Cancer Cell Metabolism in Akt-Mediated Therapy Resistance

Cancer resistance to chemotherapy, radiotherapy and molecular-targeted agents is a major obstacle to successful cancer therapy. Herein, aberrant activation of the phosphatidyl-inositol-3-kinase (PI3K)/protein kinase B (Akt) pathway is one of the most frequently deregulated pathways in cancer cells and has been associated with multiple aspects of therapy resistance. These include, for example, survival under stress conditions, apoptosis resistance, activation of the cellular response to DNA damage and repair of radiation-induced or chemotherapy-induced DNA damage, particularly DNA double strand breaks (DSB). One further important, yet not much investigated aspect of Akt-dependent signaling is the regulation of cell metabolism. In fact, many Akt target proteins are part of or involved in the regulation of metabolic pathways. Furthermore, recent studies revealed the importance of certain metabolites for protection against therapy-induced cell stress and the repair of therapy-induced DNA damage. Thus far, the likely interaction between deregulated activation of Akt, altered cancer metabolism and therapy resistance is not yet well understood. The present review describes the documented interactions between Akt, its target proteins and cancer cell metabolism, focusing on antioxidant defense and DSB repair. Furthermore, the review highlights potential connections between deregulated Akt, cancer cell metabolism and therapy resistance of cancer cells through altered DSB repair and discusses potential resulting therapeutic implications.

Digging deeper through glucose metabolism and its regulators in cancer and metastasis

Glucose metabolism enzymes and transporters play major role in cancer development and metastasis. In this study, we discuss glucose metabolism, transporters, receptors, hormones, oncogenes and tumor suppressors which interact with glucose metabolism and we try to discuss their major role in cancer development and cancer metabolism. We try to highlight the. Metabolic changes in cancer and metastasis upregulation of glycolysis is observed in many primary and metastatic cancers and aerobic glycolysis is the most favorable mechanism for glucose metabolism in cancer cells, and it is a kind of evolutionary change. The question that is posed at this juncture is: Can we use aerobic glycolysis phenotype and enzymes beyond this mechanism in estimating cancer prognosis and metastasis? Lactate is a metabolite of glucose metabolism and it is a key player in cancer and metastasis in both normoxic and hypoxic condition so lactate dehydrogenase can be a good prognostic biomarker. Furthermore, monocarboxylic transporter which is the main lactate transporter can be good target in therapeutic studies. Glycolysis enzymes are valuable enzymes in cancer and metastasis diagnosis and can be used as therapeutic targets in cancer treatment. Designing a diagnostic and prognostic profile for cancer metastasis seems to be possible base on glycolysis enzymes and glucose transporters. Also, glucose metabolism enzymes and agents can give us a clear vision in estimating cancer metastasis. We can promote a panel of genes that detect genetic changes in glucose metabolism agents to diagnose cancer metastasis.

The Warburg Effect 97 Years after Its Discovery

The deregulation of the oxidative metabolism in cancer, as shown by the increased aerobic glycolysis and impaired oxidative phosphorylation (Warburg effect), is coordinated by genetic changes leading to the activation of oncogenes and the loss of oncosuppressor genes. The understanding of the metabolic deregulation of cancer cells is necessary to prevent and cure cancer. In this review, we illustrate and comment the principal metabolic and molecular variations of cancer cells, involved in their anomalous behavior, that include modifications of oxidative metabolism, the activation of oncogenes that promote glycolysis and a decrease of oxygen consumption in cancer cells, the genetic susceptibility to cancer, the molecular correlations involved in the metabolic deregulation in cancer, the defective cancer mitochondria, the relationships between the Warburg effect and tumor therapy, and recent studies that reevaluate the Warburg effect. Taken together, these observations indicate that the Warburg effect is an epiphenomenon of the transformation process essential for the development of malignancy.

Downregulation of PER2 Promotes Tumor Progression by Enhancing Glycolysis via the Phosphatidylinositol 3-Kinase/Protein Kinase B Pathway in Oral Squamous Cell Carcinoma

PURPOSE

PER2 gene expression is downregulated in oral squamous cell carcinoma (OSCC) and may have a pivotal role in tumor suppression. However, the biological function and mechanism of action of PER2 in OSCC remain unclear. In this study, the biological functions and anticancer mechanisms of PER2 in OSCC were investigated.

MATERIALS AND METHODS

Both stably overexpressed and silenced PER2 OSCC cells were established as an experimental group; empty vector lentivirus and scramble short hairpin RNA lentivirus transfected-cells, as negative control groups; and untreated OSCC cells, as a blank group. Cell proliferation, apoptosis, and glycolysis potential assays were conducted. In addition, the expression of phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT), phosphorylation of protein kinase B, hexokinase 2 (HK2), pyruvate kinase M (PKM2), and lactate dehydrogenase A (LDHA) was quantified by real-time quantitative polymerase chain reaction and Western blotting. Rescue experiments were performed by the addition of AKT activators in the overexpressed cell line and by the addition of glycolysis inhibitor in the silenced cell line. These findings were verified in vivo using stably transfected OSCC cells overexpressing PER2 implanted in nude mice.

RESULTS

PER2 overexpression significantly inhibited OSCC cell proliferation and glycolysis, promoted cell apoptosis, and reduced the expression of PI3K, phosphorylation of protein kinase B, HK2, PKM2, and LDHA. The converse was observed in PER2-silenced OSCC cells. After the addition of AKT activator to cultures of PER2-overexpressed OSCC cells, reduced glucose uptake, lactic acid production, and cell proliferation, combined with increased apoptosis, were substantially reversed. In addition, after the addition of HK2 inhibitor to PER2-silenced OSCC cells to inhibit glycolysis, the reduction in apoptosis and increased proliferation were significantly countermanded. Tumorigenesis experiments in vivo also confirmed that PER2 overexpression suppressed OSCC growth and decreased the expression of HK2, PKM2, and LDHA.

CONCLUSIONS

PER2 heightened glycolysis via the PI3K/AKT pathway, heightened cell proliferation and inhibited apoptosis via glycolysis, thereby promoting the development of OSCC.

Zika virus dysregulates human Sertoli cell proteins involved in spermatogenesis with little effect on tight junctions

Zika virus (ZIKV), a neglected tropical disease until its re-emergence in 2007, causes microcephaly in infants and Guillain-Barré syndrome in adults. Its re-emergence and spread to more than 80 countries led the World Health Organization in 2016 to declare a Public Health Emergency. ZIKV is mainly transmitted by mosquitos, but can persist in infected human male semen for prolonged periods and may be sexually transmitted. Testicular Sertoli cells support ZIKV replication and may be a reservoir for persistent ZIKV infection. Electrical impedance analyses indicated ZIKV infection rapidly disrupted Vero cell monolayers but had little effect upon human Sertoli cells (HSerC). We determined ZIKV-induced proteomic changes in HSerC using an aptamer-based multiplexed technique (SOMAscan) targeting >1300 human proteins. ZIKV infection caused differential expression of 299 proteins during three different time points, including 5 days after infection. Dysregulated proteins are involved in different bio-functions, including cell death and survival, cell cycle, maintenance of cellular function, cell signaling, cellular assembly, morphology, movement, molecular transport, and immune response. Many signaling pathways important for maintenance of HSerC function and spermatogenesis were highly dysregulated. These included IL-6, IGF1, EGF, NF-κB, PPAR, ERK/MAPK, and growth hormone signaling. Down-regulation of the PPAR signaling pathway might impact cellular energy supplies. Upstream molecule analysis also indicated microRNAs involved in germ cell development were downregulated by infection. Overall, this study leads to a better understanding of Sertoli cellular mechanisms used by ZIKV during persistent infection and possible ZIKV impacts on spermatogenesis.

Phosphoglycerate Mutase 1 Activates DNA Damage Repair via Regulation of WIP1 Activity

The metabolic enzyme phosphoglycerate mutase 1 (PGAM1) is overexpressed in several types of cancer, suggesting an additional function beyond its established role in the glycolytic pathway. We here report that PGAM1 is overexpressed in gliomas where it increases the efficiency of the DNA damage response (DDR) pathway by cytoplasmic binding of WIP1 phosphatase, thereby preventing WIP1 nuclear translocation and subsequent dephosphorylation of the ATM signaling pathway. Silencing of PGAM1 expression in glioma cells consequently decreases formation of γ-H2AX foci, increases apoptosis, and decreases clonogenicity following irradiation (IR) and temozolomide (TMZ) treatment. Furthermore, mice intracranially implanted with PGAM1-knockdown cells have significantly improved survival after treatment with IR and TMZ. These effects are counteracted by exogenous expression of two kinase-dead PGAM1 mutants, H186R and Y92F, indicating an important non-enzymatic function of PGAM1. Our findings identify PGAM1 as a potential therapeutic target in gliomas.

Novel anthraquinone compounds as anticancer agents and their potential mechanism

Anthraquinones exhibit a unique anticancer activity. Since their discovery, medicinal chemists have made several structural modifications, resulting in the design and synthesis of a large number of novel anthraquinone compounds with different biological activities. In general, anthraquinone compounds have been considered to have anticancer activity mainly through DNA damage, cycle arrest and apoptosis. However, recent studies have shown that novel anthraquinone compounds may also inhibit cancer through paraptosis, autophagy, radiosensitising, overcoming chemoresistance and other methods. This Review article provides an overview of novel anthraquinone compounds that have been developed as anticancer agents in recent years and focuses on their anticancer mechanism.

Circ-PGAM1 promotes malignant progression of epithelial ovarian cancer through regulation of the miR-542-3p/CDC5L/PEAK1 pathway

Background

Epithelial ovarian cancer (EOC) is the most common ovarian malignant cancer. Circular RNA is a type of endogenous noncoding RNA and is considered as a novel regulatory molecule in the development and progression of tumors. This study investigated the expression and functions of a circular RNA, circular‐phosphoglycerate mutase 1 (circ‐PGAM1), in EOC tissues and cells.

Methods

The expression of circ‐PGAM1 and miR‐542‐3p in EOC was analyzed using quantitative RT‐PCR. Immunohistochemistry and western blot were performed to confirm the localization and expression of cell division cycle 5‐like (CDC5L) and pseudopodium enriched atypical kinase 1 (PEAK1) in EOC tissues. Cell lines (CAOV3 and OVCAR3) overexpressing or silencingcirc‐PGAM1 and miR‐542‐3p were established to explore the functions of circ‐PGAM1 and miR‐542‐3p in ovarian cancer cells. Furthermore, dual‐luciferase reporter assay was performed to study the interactions between circ‐PGAM1 and miR‐542‐3p and between miR‐542‐3p and CDC5L. CCK‐8, transwell, and flow cytometry were used to study the effect of circ‐PGAM1 and miR‐542‐3p on cell biological behaviors including proliferation, migration, invasion, and apoptosis. The interaction between CDC5L and the PEAK1 gene promoter was confirmed using chromatin immunoprecipitation (ChIP).

Results

Circ‐PGAM1 was upregulated in EOC tissues, whereas linear PGAM1 was not deregulated in EOC tissues. Silencing of circ‐PAGM1 inhibited proliferation, migration, and invasion of ovarian cancer cells and promoted cell apoptosis. MiR‐542‐3p was downregulated in EOC tissues, and miR‐542‐3p overexpression inhibited malignant progression of ovarian cancer cells. Circ‐PGAM1 directly interacted with miR‐542‐3p, with mutual negative feedback between them. CDC5L was a direct target of miR‐542‐3p and played an oncogenic role in ovarian cancer cells. Furthermore, the CDC5L protein binds directly to the PEAK1 promoter to promote its transcription. PEAK1 overexpression activated ERK1/2 and JAK2 signaling pathways and promoted malignant biological behaviors of ovarian cancer cells. Circ‐PAGM1 silencing combined with miR‐542‐3p overexpression played the greatest anticancer role in vivo.

Conclusion

The circ‐PGAM1/miR‐542‐3p/CDC5L/PEAK1 pathway played an important role in the progression of ovarian cancer and might be a novel therapeutic target for ovarian cancer.

Decreased FBP1 expression rewires metabolic processes affecting aggressiveness of glioblastoma

Radiotherapy is a standard treatment option for patients with glioblastoma (GBM). Although it has high therapeutic efficacy, some proportion of the tumor cells that survive after radiotherapy may cause side effects. In this study, we found that fructose 1,6-bisphosphatase 1 (FBP1), a rate-limiting enzyme in gluconeogenesis, was downregulated upon treatment with ionizing radiation (IR). Ets1, which was found to be overexpressed in IR-induced infiltrating GBM, was suggested to be a transcriptional repressor of FBP1. Furthermore, glucose uptake and extracellular acidification rates were increased upon FBP1 downregulation, which indicated an elevated glycolysis level. We found that emodin, an inhibitor of phosphoglycerate mutase 1 derived from natural substances, significantly suppressed the glycolysis rate and IR-induced GBM migration in in vivo orthotopic xenograft mouse models. We propose that the reduced FBP1 level reprogrammed the metabolic state of GBM cells, and thus, FBP1 is a potential therapeutic target regulating GBM metabolism following radiotherapy.

Cadmium induces GAPDH- and- MDH mediated delayed cell aging and dysfunction in Candida tropicalis 3Aer

Eukaryotes employ various mechanisms to survive environmental stress conditions. Multicellular organisms eliminate permanently damaged cells by apoptosis, while unicellular eukaryotes like yeast react by decelerating cell aging. In the present study, transcriptomic and proteomic approaches were employed to elucidate the underlying mechanism of delayed apoptosis. Our findings suggest that Candida tropicalis 3Aer has a set of tightly controlled genes that are activated under Cd⁺² exposition. Acute exposure to Cd⁺² halts the cell cycle at the G₂/M phase checkpoint and activates multiple cytoplasmic proteins that overcome effects of Cd⁺²-induced reactive oxygen species. Prolonged Cd⁺² stress damages DNA and initiates GAPDH amyloid formation. This is the first report that Cd⁺² challenge initiates dynamic redistribution of GAPDH and MDH and alters various metabolic pathways including the pentose phosphate pathway. In conclusion, the intracellular redistribution of GAPDH and MDH induced by prolonged cadmium stress modulates various cellular reactions, which facilitate delayed aging in the yeast cell.

Analysis of the Antiproliferative Effect of Ankaferd Hemostat on Caco-2 Colon Cancer Cells via LC/MS Shotgun Proteomics Approach

Ankaferd hemostat (ABS), a traditional herbal extract, is a hemostatic agent used for wound healing and bleeding treatment. A standardized form of plants contains many biomolecules. In recent years, previous studies have demonstrated the antineoplastic effect of ABS. In the present work, we focused on the mechanism of its antineoplastic effect over Caco-2 colon cancer cells. The LC/MS-based proteomics method was used to understand the effect of ABS at the protein level. The results were evaluated with gene ontology, protein interaction, and pathway analysis. As shown by our results, ABS altered glucose, fatty acids, and protein metabolism. Moreover, ABS affects the cell cycle machinery. Moreover, we found that ABS induced critical cancer target and suppressor proteins such as carboxyl-terminal hydrolase 1, 60S ribosomal protein L5, Tumor protein D52-like2, karyopherin alpha 2, and protein deglycase DJ-1. In conclusion, the proteomics results indicated that ABS affects various cancer targets and suppressor proteins. Moreover ABS has systematical effect on cell metabolism and cell cycle in Caco-2 cells, suggesting that it could be used as an antineoplastic agent.

Phosphoglycerate mutase 1 knockdown inhibits prostate cancer cell growth, migration, and invasion

Phosphoglycerate mutase 1 (PGAM1) is upregulated in many cancer types and involved in cell proliferation, migration, invasion, and apoptosis. However, the relationship between PGAM1 and prostate cancer is poorly understood. The present study investigated the changes in PGAM1 expression in prostate cancer tissues compared with normal prostate tissues and examined the cellular function of PGAM1 and its relationship with clinicopathological variables. Immunohistochemistry and Western blotting revealed that PGAM1 expression was upregulated in prostate cancer tissues and cell lines. PGAM1 expression was associated with Gleason score (P = 0.01) and T-stage (P = 0.009). Knockdown of PGAM1 by siRNA in PC-3 and 22Rv1 prostate cancer cell lines inhibited cell proliferation, migration, and invasion and enhanced cancer cell apoptosis. In a nude mouse xenograft model, PGAM1 knockdown markedly suppressed tumor growth. Deletion of PGAM1 resulted in decreased expression of Bcl-2, enhanced expression of Bax, caspases-3 and inhibition of MMP-2 and MMP-9 expression. Our results indicate that PGAM1 may play an important role in prostate cancer progression and aggressiveness, and that it might be a valuable marker of poor prognosis and a potential therapeutic target for prostate cancer.

Enhanced Pyruvate Production in Candida glabrata by Engineering ATP Futile Cycle System

Energy metabolism plays an important role in the growth and central metabolic pathways of cells. Manipulating energy metabolism is an efficient strategy to improve the formation of target products and to understand the effects of altering intracellular energy levels on global metabolic networks. Candida glabrata, as a dominant yeast strain for producing pyruvate, principally converts glucose to pyruvate through the glycolytic pathway. However, this process can be severely inhibited by a high intracellular ATP content. Here, in combination with the physiological characteristics of C. glabrata, efforts have been made to construct an ATP futile cycle system (ATP-FCS) in C. glabrata to decrease the intracellular ATP level without destroying F₀F₁-ATPase function. ATP-FCS was capable of decreasing the intracellular ATP level by 51.0% in C. glabrata. The decrease in the ATP level directly led to an increased pyruvate production and glycolysis efficiency. Moreover, we further optimized different aspects of the ATP-FCS to maximize pyruvate accumulation. Combining ATP-FCS with further genetic optimization strategies, we achieved a final pyruvate titer of 40.2 g/L, with 4.35 g pyruvate/g dry cell weight and a 0.44 g/g substrate conversion rate in 500 mL flasks, which represented increases of 98.5%, 322.3%, and 160%, respectively, compared with the original strain. Thus, these strategies hold great potential for increasing the synthesis of other organic acids in microbes.

PGAM1 knockdown is associated with busulfan‑induced hypospermatogenesis and spermatogenic cell apoptosis

Phosphoglycerate mutase 1 (PGAM1) is reported to be involved in spermatogenic dysfunction. However, the association between PGAM1 and busulfan-induced hypospermatogenesis and spermatogenic cell apoptosis remains unclear. The aim of the current study was to investigate the association between PGAM1 expression and busulfan-induced hypospermatogenesis, and the effect of PGAM1 expression on spermatogenic cell apoptosis. PGAM1 expression was detected in mouse models of busulfan-induced hypospermatogenesis by western blotting, reverse transcription-quantitative polymerase chain reaction and immunohistochemistry. Then, spermatogenic cell apoptosis in mouse models of busulfan-induced hypospermatogenesis was assessed by TUNEL assay. The effect and potential mechanism of PGAM1 downregulation on spermatogenic cells were further investigated. The results indicated that PGAM1 expression was significantly downregulated in the mouse models of busulfan-induced hypospermatogenesis, compared with those with normal spermatogenesis (P<0.05). Furthermore, the TUNEL assay revealed that the apoptosis of spermatogenic cells was accelerated in the mouse model of busulfan-induced hypospermatogenesis. In addition, PGAM1 knockdown promoted the apoptosis of spermatogenic cells in vitro, which was associated with the P53/Caspase 3/Caspase 6/Caspase 9 signaling pathway. In conclusion, these data indicate that PGAM1 knockdown is associated with busulfan-induced hypospermatogenesis and contributes to spermatogenic cell apoptosis by regulating the P53/Caspase 3/Caspase 6/Caspase 9 signaling pathway.

S1P/S1PR3 axis promotes aerobic glycolysis by YAP/c-MYC/PGAM1 axis in osteosarcoma

Background

Osteosarcoma (OS) is a malignant tumor mainly occurring in young people. Due to the limited effective therapeutic strategies, OS patients cannot achieve further survival improvement. G-protein-coupled receptors (GPCRs) constitute the largest family of cell membrane receptors and consequently hold the significant promise for tumor imaging and targeted therapy. We aimed to explore the biological functions of Sphingosine 1-phosphate receptor 3 (S1PR3), one of the members of GPCRs family, in OS and the possibility of S1PR3 as an effective target for the treatment of osteosarcoma.

Methods

The quantitative real time PCR (qRT-PCR) and western blotting were used to analyze the mRNA and protein expressions. Cell counting kit-8 (CCK8), colony formation assay and cell apoptosis assay were performed to test the cellular proliferation in vitro. Subcutaneous xenograft mouse model was generated to evaluate the functions of S1PR3 in vivo. RNA sequencing was used to compare gene expression patterns between S1PR3-knockdown and control MNNG-HOS cells. In addition, metabolic alternations in OS cells were monitored by XF96 metabolic flux analyzer. Co-immunoprecipitation (Co-IP) assay was used to explore the interaction between Yes-associated protein (YAP) and c-MYC. Chromatin immunoprecipitation was used to investigate the binding capability of PGAM1 and YAP or c-MYC. Moreover, the activities of promoter were determined by the luciferase reporter assay.

Findings

S1PR3 and its specific ligand Sphingosine 1-phosphate (S1P) were found elevated in OS, and the higher expression of S1PR3 was correlated with the poor survival rate. Moreover, our study has proved that the S1P/S1PR3 axis play roles in proliferation promotion, apoptosis inhibition, and aerobic glycolysis promotion of osteosarcoma cells. Mechanistically, the S1P/S1PR3 axis inhibited the phosphorylation of YAP and promoted the nuclear translocation of YAP, which contributed to the formation of the YAP–c-MYC complex and enhanced transcription of the important glycolysis enzyme PGAM1. Moreover, the S1PR3 antagonist TY52156 exhibited in vitro and in vivo synergistic inhibitory effects with methotrexate on OS cell growth.

Interpretation

Our study unveiled a role of S1P, a bioactive phospholipid, in glucose metabolism reprogram through interaction with its receptor S1PR3. Targeting S1P/S1PR3 axis might serve as a potential therapeutic target for patients with OS.

Fund

This research was supported by National Natural Science Foundation of China (81472445 and 81672587).

Proteomic analysis of rat serum revealed the effects of chronic sleep deprivation on metabolic, cardiovascular and nervous system

Sleep is an essential and fundamental physiological process that plays crucial roles in the balance of psychological and physical health. Sleep disorder may lead to adverse health outcomes. The effects of sleep deprivation were extensively studied, but its mechanism is still not fully understood. The present study aimed to identify the alterations of serum proteins associated with chronic sleep deprivation, and to seek for potential biomarkers of sleep disorder mediated diseases. A label-free quantitative proteomics technology was used to survey the global changes of serum proteins between normal rats and chronic sleep deprivation rats. A total of 309 proteins were detected in the serum samples and among them, 117 proteins showed more than 1.8-folds abundance alterations between the two groups. Functional enrichment and network analyses of the differential proteins revealed a close relationship between chronic sleep deprivation and several biological processes including energy metabolism, cardiovascular function and nervous function. And four proteins including pyruvate kinase M1, clusterin, kininogen1 and profilin-1were identified as potential biomarkers for chronic sleep deprivation. The four candidates were validated via parallel reaction monitoring (PRM) based targeted proteomics. In addition, protein expression alteration of the four proteins was confirmed in myocardium and brain of rat model. In summary, the comprehensive proteomic study revealed the biological impacts of chronic sleep deprivation and discovered several potential biomarkers. This study provides further insight into the pathological and molecular mechanisms underlying sleep disorders at protein level.

Dysregulation of the NUDT7-PGAM1 axis is responsible for chondrocyte death during osteoarthritis pathogenesis

Osteoarthritis (OA) is the most common degenerative joint disease; however, its etiopathogenesis is not completely understood. Here we show a role for NUDT7 in OA pathogenesis. Knockdown of NUDT7 in normal human chondrocytes results in the disruption of lipid homeostasis. Moreover, Nudt7-/- mice display significant accumulation of lipids via peroxisomal dysfunction, upregulation of IL-1β expression, and stimulation of apoptotic death of chondrocytes. Our genome-wide analysis reveals that NUDT7 knockout affects the glycolytic pathway, and we identify Pgam1 as a significantly altered gene. Consistent with the results obtained on the suppression of NUDT7, overexpression of PGAM1 in chondrocytes induces the accumulation of lipids, upregulation of IL-1β expression, and apoptotic cell death. Furthermore, these negative actions of PGAM1 in maintaining cartilage homeostasis are reversed by the co-introduction of NUDT7. Our results suggest that NUDT7 could be a potential therapeutic target for controlling cartilage-degrading disorders.

Identification of PGAM1 as a putative therapeutic target for pancreatic ductal adenocarcinoma metastasis using quantitative proteomics

Background

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive gastrointestinal cancer characterized by an extremely low survival rate because of early metastasis. Identifying satisfactory therapeutic targets associated with metastasis is crucial to improve the treatment effect of PDAC.

Materials and methods

In this research, we used stable isotope labeling by amino acids in cell culture, 1-dodecyl-3-methylimidazolium chloride-assisted sample preparation method preparing protein sample and nano-reversed-phase liquid chromatography-mass spectrometry/mass spectrometry analysis to perform the comparative proteomics of two homologous hamster pancreatic cancer cell lines that are different in metastatic ability: PC-1.0 (highly metastatic) and PC-1 (weakly metastatic). Verifications are through immunohistochemistry on clinical human PDAC pathologic tissues as well as by Western blot of human pancreatic cancer cell lines. siRNA silencing methods were used to study the effect of molecules on invasion and metastasis of pancreatic cancer cell lines.

Results

Bioinformatic analysis indicated that a total of 141 differentially expressed proteins (82 upregulated and 59 downregulated in PC-1.0 cells) were identified showing obviously differential expression (>1.5-fold change). These differentially expressed proteins were involved in a number of different biologic functions, metabolic pathways, and pathophysiologic processes. Phosphoglycerate mutase 1 (PGAM1) and HSPE1 are the top two upregulated proteins, and PDIA3 and CALR are the top two downregulated proteins in PC-1.0 cells compared to PC-1 cells. PGAM1 and HSPE1 showed higher expressions in PDAC tissue with clinical metastasis and highly metastatic pancreatic cancer cell lines PC-1.0 and Aspc-1. PDIA3 and CALR showed higher expressions in weakly metastatic pancreatic cancer cell lines PC-1 and Capan-2. The Western blot results were consistent with the MS quantification data. Silencing PGAM1 was found to decrease the migration and invasion of pancreatic cancer cell lines with statistical significance, especially in highly metastatic PC-1.0 and Aspc-1 cell lines.

Conclusion

These data indicated that PGAM1 may be a potential therapeutic target for PDAC metastasis.

Phosphoglyceric acid mutase-1 contributes to oncogenic mTOR-mediated tumor growth and confers non-small cell lung cancer patients with poor prognosis

As a hallmark of cancer, the Warburg effect (aerobic glycolysis) confers a selective advantage for the survival and proliferation of cancer cells. Due to frequent aberration of upstream proto-oncogenes and tumor suppressors, hyperactive mammalian/mechanistic target of rapamycin (mTOR) is a potent inducer of the Warburg effect. Here, we report that overexpression of a glycolytic enzyme, phosphoglyceric acid mutase-1 (PGAM1), is critical to oncogenic mTOR-mediated Warburg effect. mTOR stimulated PGAM1 expression through hypoxia-inducible factor 1α-mediated transcriptional activation. Blockage of PGAM1 suppressed mTOR-dependent glycolysis, cell proliferation, and tumorigenesis. PGAM1 expression and mTOR activity were positively correlated in non-small cell lung cancer (NSCLC) tissues and PGAM1 abundance was an adverse predictor for patient survival. PGAM1 is thus a downstream effector of mTOR signaling pathway and mTOR-PGAM1 signaling cascade may contribute to the development of Warburg effect observed in cancer. We consider PGAM1 as a novel prognostic biomarker for NSCLC and a therapeutic target for cancer.

Diabetic Retinopathy and Laser Therapy in Rats: A Protein-Protein Interaction Network Analysis

Introduction: Diabetic retinopathy (DR) is a serious microvascular complication of diabetes which can cause vision loss or blindness ultimately. Non enzymatic glycation of proteins leads to advanced glycation end products (AGEs) in DR. Since laser therapy is a well-established method, in this study, protein-protein interaction (PPI) network is applied for protein targets in DR disease in rats treated by laser. Methods: In this study, we focused on articles that investigated and compared the proteome profiles of DR rats with healthy control and also DR rats before and after laser therapy. The networks of related differentially expressed proteins were explored using Cytoscape version 3.3.0, the PPI analysis methods and ClueGO. Results: Analysis of PPI network of 37 related proteins to DR rats including 108 nodes, introduced 10 hub-bottleneck proteins and 5 concerned biochemical pathways. On the other hand, PPI analysis of related proteins to DR rats before and after laser therapy corresponded to 33 proteins and 2 biological pathways. Discussion: Centrality and cluster screening identified hub-bottelneck genes, including Aldoa, HSPD1, Pgam2, Mapk3, SLC2A4, Ctnnb1, Ywhab, HSPA8, GAPDH and Actb for DR rats versus healthy control and ENO1, Aldoa, GAPDH for DR samples after laser therapy.

CONCLUSION

Gene expression analysis of the DR samples treated via laser therapy provides a molecular evidence in support of the therapeutic effect of laser.

Phosphoglycerate Mutase 1 Predicts the Poor Prognosis of Oral Squamous Cell Carcinoma and is Associated with Cell Migration

Oral squamous cell carcinoma (OSCC) is a common malignant tumor with high metastatic potential. However, no good biomarker has been identified to refine which subtype is of high metastatic potential to make decisions regarding the elective and therapeutic management of lymphatic metastases. In this study, we investigated the role of the metabolic enzyme phosphoglycerate mutase 1 (PGAM1) in OSCC. PGAM1 expression was examined in tissue samples of 122 OSCC patients using immunohistochemistry, and the correlation between clinicopathological expression and PGAM1 expression was determined. Survival curves were generated using the Kaplan-Meier method, and multivariate analysis was performed by the Cox proportional hazards model. Moreover, PGAM1 was knocked down in the OSCC cell lines Cal27 and HN12, followed by determination of the change in cell migration and signaling pathways. PGAM1 expression is correlated with age, lymphatic metastasis and tumor recurrence and is closely associated with poor overall survival (OS) and disease-free survival (DFS). Intriguingly, PGAM1 is an independent risk factor for OS and DFS. After knocking down PGAM1 in Cal27 and HN12 cells, cell migration was remarkably decreased along with signaling pathway molecules, such as proto-oncogene c-SRC (SRC), Focal adhesion kinase (FAK) and Paxillin. The effect on cell migration was abolished following pretreatment with an SRC inhibitor. This study suggested that PGAM1 is a poor prognostic biomarker of OSCC and may be used to select patients of high metastatic potential in the clinic, and PGAM1 promotes the migration of OSCC cells is associated with the SRC pathway.

Mitochondria in Cancer Energy Metabolism: Culprits or Bystanders?

Cancer is a disease characterized by uncontrolled growth. Metabolic demands to sustain rapid proliferation must be compelling since aerobic glycolysis is the first as well as the most commonly shared characteristic of cancer. During the last decade, the significance of metabolic reprogramming of cancer has been at the center of attention. Nonetheless, despite all the knowledge gained on cancer biology, the field is not able to reach agreement on the issue of mitochondria: Are damaged mitochondria the cause for aerobic glycolysis in cancer? Warburg proposed the damaged mitochondria theory over 80 years ago; the field has been testing the theory equally long. In this review, we will discuss alterations in metabolic fluxes of cancer cells, and provide an opinion on the damaged mitochondria theory.

Reprogramming of glucose, fatty acid and amino acid metabolism for cancer progression

Metabolic reprogramming is widely observed during cancer development to confer cancer cells the ability to survive and proliferate, even under the stressed, such as nutrient-limiting, conditions. It is famously known that cancer cells favor the "Warburg effect", i.e., the enhanced glycolysis or aerobic glycolysis, even when the ambient oxygen supply is sufficient. In addition, deregulated anabolism/catabolism of fatty acids and amino acids, especially glutamine, serine and glycine, have been identified to function as metabolic regulators in supporting cancer cell growth. Furthermore, extensive crosstalks are being revealed between the deregulated metabolic network and cancer cell signaling. These exciting advancements have inspired new strategies for treating various malignancies by targeting cancer metabolism. Here we review recent findings related to the regulation of glucose, fatty acid and amino acid metabolism, their crosstalk, and relevant cancer therapy strategy.