Glycolysis Signaling Pathway Research Articles

Baicalein suppresses inflammation and attenuates acute lung injury by inhibiting glycolysis via HIF‑1α signaling.

Baicalein, a flavonoid monomer compound isolated from the dried root of the traditional Chinese herb Scutellaria baicalensis, has several pharmacological activities, such as anti‑inflammatory, anti‑angiogenic, antitumor, antimicrobial and antiviral properties. Acute lung injury (ALI) is characterized by injury of the alveolar epithelium and capillary endothelium, which results in decreased lung volume, decreased lung compliance, ventilation/perfusion mismatch, intrapulmonary edema, alveolar edema and even acute hypoxemic respiratory failure. The present study aimed to investigate the effects of baicalein on lung injury and inflammation. Bioinformatics analysis using network pharmacology predicted that the hypoxia inducible factor‑1α (HIF‑1α) and glycolysis signaling pathways were involved in the mechanism underlying the therapeutic effects of baicalein. Further in vitro and in vivo experiments, such as immunohistochemistry, immunofluorescence and PCR, verified that baicalein could inhibit HIF‑1α signaling, thus suppressing glycolysis, and improving inflammatory responses and ALI. Taken together, the results of the present study suggested that the anti‑inflammatory effects of baicalein on treating ALI were associated with its ability to suppress glycolysis via the HIF‑1α signaling pathway.

SLC45A4 is involved in malignant progression of ovarian cancer through glycolytic metabolic reprogramming

Tumor cells promote malignant behaviors such as proliferation, invasion, and metastasis of cancer cells through glucose metabolic reprogramming, but the role of the H-dependent sugar cotransporter SLC45A4 in regulating metabolic reprogramming in ovarian cancer (OC) remains largely unknown. This study aimed to investigate the effects of SLC45A4 silencing on the transcriptome spectrum of ovarian cancer cells (OCC), glucose uptake, lactic acid production, intracellular ATP levels, and the expression and activity of HIF-α glycolysis signaling pathway. The results showed that SLC45A4 is overexpressed in OC and its elevated expression correlates with adverse clinical outcomes in OC patients. Silencing of SLC45A4 significantly inhibited the proliferation, invasion, and metastasis of OCC by suppressing glucose uptake and glycolysis, and it also reduced the expression of HIF-α glycolysis signaling pathway in OC tissues. In vivo experiments using shRNA to knock down SLC45A4 in xenograft models in nude mice demonstrated a significant inhibition of tumor growth. These findings suggest that SLC45A4 silencing can restrain the malignant progression of OC by inhibiting glucose uptake in OCC and affecting the reprogramming of glycolytic energy metabolism, indicating that SLC45A4 may serve as a potential therapeutic target for OC intervention.

TRIP13 Activates Glycolysis to Promote Cell Stemness and Strengthen Doxorubicin Resistance of Colorectal Cancer Cells.

Chemotherapy resistance is one of the main causes of clinical chemotherapy failure. Current cancer research explores the drug resistance mechanism and new therapeutic targets. This work aims to elucidate the mechanism of thyroid hormone receptor interactor 13 (TRIP13) affecting doxorubicin (DOX) resistance in colorectal cancer (CRC). Bioinformatics analyses were employed to clarify TRIP13 expression in CRC tissues and predict the correlation of the TRIP13 enrichment pathway with glycolysis-related genes and stemness index mRNAsi. Quantitative real-time polymerase chain reaction and western blot were adopted to analyze the expression of TRIP13 and glycolysis- related genes. Cell Counting Kit-8 was utilized to determine the cell viability and IC50 value. Western blot was employed to measure the expression of stemness-related factors. Cell function assays were performed to detect cells' sphere-forming ability and glycolysis level. Animal models were constructed to determine the effects of TRIP13 expression on CRC tumor growth. TRIP13 was significantly overexpressed in CRC, concentrated in the glycolysis signaling pathway, and positively correlated with stemness index mRNAsi. High expression of TRIP13 facilitated DOX resistance in CRC. Further mechanistic studies revealed that overexpression of TRIP13 could promote cell stemness through glycolysis, which was also confirmed in animal experiments. TRIP13 was highly expressed in CRC, which enhanced the DOX resistance of CRC cells by activating glycolysis to promote cell stemness. These findings offer new insights into the pathogenesis of DOX resistance in CRC and suggest that TRIP13 may be a new target for reversing DOX resistance in CRC.

PLA2G2D fosters angiogenesis in non-small cell lung cancer through aerobic glycolysis

Non-small cell lung cancer (NSCLC) stands prominent among the prevailing and formidable oncological entities. The immune and metabolic-related molecule Phospholipase A2, group IID (PLA2G2D) exerts promotional effects on tumor progression. However, its involvement in cancer angiogenesis remains elusive. Therefore, this investigation delved into the functional significance of PLA2G2D concerning angiogenesis in NSCLC. This study analyzed the expression and enriched pathways of PLA2G2D in NSCLC tissues through bioinformatics analysis, and measured the expression of PLA2G2D in NSCLC cells using qRT-PCR and western blot (WB). Subsequently, the viability and angiogenic potential of NSCLC cells were assessed employing CCK-8 and angiogenesis assays, respectively. The expression profile of angiogenic factors was analyzed through WB. Finally, the expression of glycolysis pathway-related genes, extracellular acidification rate and oxygen consumption rate, and the levels of pyruvate, lactate, citrate, and malate were analyzed in NSCLC cells using qRT-PCR, Seahorse XF 96, and related kits. Bioinformatics analysis revealed the upregulation of PLA2G2D in NSCLC tissues and its association with VEGF and glycolysis signaling pathways. Molecular and cellular experiments demonstrated that upregulated PLA2G2D promoted the viability, angiogenic ability, and glycolysis pathway of NSCLC cells. Rescue assays revealed that the effects of high expression of PLA2G2D on the viability, angiogenic ability, and glycolysis of NSCLC cells were weakened after the addition of the glycolysis inhibitor 2-DG. In summary, PLA2G2D plays a key role in NSCLC angiogenesis through aerobic glycolysis, displaying great potential as a target for anti-angiogenesis therapy.

Zinc finger and SCAN domain-containing protein 18 is a potential DNA methylation-modified tumor suppressor and biomarker in breast cancer.

Zinc finger and SCAN domain-containing protein 18 (ZSCAN18) has been investigated as a putative biomarker of multiple human cancers. However, the expression profile, epigenetic modification, prognostic value, transcription regulation, and molecular mechanism of ZSCAN18 in breast cancer (BC) remain unknown. In the study, we present an integrated analysis of ZSCAN18 in BC based on public omics datasets with the use of multiple bioinformatics tools. Genes potentially regulated through restoration of ZSCAN18 expression in MDA-MB-231 cells were investigated to identify pathways associated with BC. We observed that ZSCAN18 was downregulated in BC and mRNA expression was significantly correlated with clinicopathological parameters. Low expression of ZSCAN18 was found in the HER2-positive and TNBC subtypes. High expression of ZSCAN18 was associated with good prognosis. As compared to normal tissues, the extent of ZSCAN18 DNA methylation was greater with fewer genetic alterations in BC tissues. ZSCAN18 was identified as a transcription factor that might be involved in intracellular molecular and metabolic processes. Low ZSCAN18 expression was associated with the cell cycle and glycolysis signaling pathway. Overexpression of ZSCAN18 inhibited mRNA expression of genes associated with the Wnt/β-catenin and glycolysis signaling pathways, including CTNNB1, BCL9, TSC1, and PFKP. ZSCAN18 expression was negatively correlated with infiltrating B cells and dendritic cells (DCs), as determined by the TIMER web server and reference to the TISIDB. ZSCAN18 DNA methylation was positively correlated with activated B cells, activated CD8+ and CD4+ T cells, macrophages, neutrophils, and activated DCs. Moreover, five ZSCAN18-related hub genes (KDM6B, KAT6A, KMT2D, KDM1A, and HSPBP1) were identified. ZSCAN18, ZNF396, and PGBD1 were identified as components of a physical complex. ZSCAN18 is a potential tumor suppressor in BC, as expression is modified by DNA methylation and associated with patient survival. In addition, ZSCAN18 plays important roles in transcription regulation, the glycolysis signaling pathway, and the tumor immune microenvironment.

Silk fibroin and sericin differentially potentiate the paracrine and regenerative functions of stem cells through multiomics analysis.

Silk fibroin (SF) and sericin (SS), the two major proteins of silk, are attractive biomaterials with great potential in tissue engineering and regenerative medicine. However, their biochemical interactions with stem cells remain unclear. In this study, we employed multiomics to obtain a global view of the cellular processes and pathways of mesenchymal stem cells (MSCs) triggered by SF and SS to discern cell-biomaterial interactions at an in-depth, high-throughput molecular level. Integrated RNA sequencing and proteomic analysis confirmed that SF and SS initiated widespread but distinct cellular responses and potentiated the paracrine functions of MSCs that regulate extracellular matrix deposition, angiogenesis, and immunomodulation through differentially activating the integrin/PI3K/Akt and glycolysis signaling pathways. These paracrine signals of MSCs stimulated by SF and SS effectively improved skin regeneration by regulating the behavior of multiple resident cells (fibroblasts, endothelial cells, and macrophages) in the skin wound microenvironment. Compared to SS, SF exhibited better immunomodulatory effects in vitro and in vivo, indicating its greater potential as a carrier material of MSCs for skin regeneration. This study provides comprehensive and reliable insights into the cellular interactions with SF and SS, enabling the future development of silk-based therapeutics for tissue engineering and stem cell therapy. This article is protected by copyright. All rights reserved.

Extra Spindle Pole Bodies-Like 1 Serves as a Prognostic Biomarker and Promotes Lung Adenocarcinoma Metastasis

Extra spindle pole bodies-like 1 (ESPL1), a cysteine endopeptidase, plays a vital role in chromosome inheritance. However, the association of ESPL1 with prognosis and immune infiltration in lung adenocarcinoma (LUAD) has not yet been explored. Here, we analyzed the expression level, prognostic values, diagnostic value, and immune infiltration level in LUAD using various databases. Immunohistochemistry (IHC) and quantitative real-time PCR (qRT-PCR) assays were used to detect the expression of ESPL1 in LUAD tissues and cell lines. In this study, we found that ESPL1 was upregulated in LUAD and a higher expression of ESPL1 was correlated with unfavorable prognosis in LUAD. Meanwhile, Cox hazard regression analysis results suggested that ESPL1 may be an independent prognostic factor for LUAD. Moreover, we demonstrated that ESPL1 expression was significantly correlated with immune infiltration of Th2 and dendritic cells in LUAD. We also confirmed that DNA copy number amplification and DNA hypo-methylation were positively correlated with ESPL1 expression in LUAD. Additionally, DNA copy number amplification was significantly associated with adverse clinical outcomes in LUAD. Kyoto Encyclopedia of Genes and Genomes (KEGG) and gene set enrichment analysis (GSEA) confirmed that ESPL1 was mainly involved in the DNA replication and glycolysis signaling pathway. Finally, we revealed that ESPL1 was highly expressed in LUAD tissues and cell lines. Knockdown of ESPL1 significantly inhibited cell migration and the invasion abilities of LUAD. Our study comprehensively confirmed that ESPL1 expression may serve as a novel prognostic biomarker for both the clinical outcome and immune cell infiltration in LUAD.

Impairment of Glucose Metabolism and Suppression of Stemness in MCF-7/SC Human Breast Cancer Stem Cells by Nootkatone.

Targeting cancer stem cell metabolism has emerged as a promising therapeutic strategy for cancer treatment. Breast cancer stem cells (BCSCs) exert distinct metabolism machinery, which plays a major role in radiation and multidrug resistance. Therefore, exploring the mechanisms involved in energy utilization of BCSCs could improve the effectiveness of therapeutic strategies aimed at their elimination. This study was conducted to clarify the glucose metabolism machinery and the function of nootkatone, a bioactive component of grapefruit, in regulating glucose metabolism and stemness characteristics in human breast carcinoma MCF-7 stem cells (MCF-7SCs). In vivo experiments, transcriptomic analysis, seahorse XF analysis, MTT assay, Western blotting, mammosphere formation, wound healing, invasion assay, flow cytometric analysis, reverse transcription-quantitative polymerase chain reaction, and in silico docking experiments were performed. MCF-7SCs showed a greater tumorigenic capacity and distinct gene profile with enrichment of the genes involved in stemness and glycolysis signaling pathways compared to parental MCF-7 cells, indicating that MCF-7SCs use glycolysis rather than oxidative phosphorylation (OXPHOS) for their energy supply. Nootkatone impaired glucose metabolism through AMPK activation and reduced the stemness characteristics of MCF-7SCs. In silico docking analysis demonstrated that nootkatone efficiently bound to the active site of AMPK. Therefore, this study indicates that regulation of glucose metabolism through AMPK activation could be an attractive target for BCSCs.

MiR-26a enhances colorectal cancer cell growth by targeting RREB1 deacetylation to activate AKT-mediated glycolysis.

We previously reported the inhibitory effects of microRNA-26a (miR-26a) on the conversion of pyruvate to acetyl coenzyme A in glucose metabolism by directly targeting pyruvate dehydrogenase protein X component in colorectal cancer (CRC) cells (Chen B et al., BMC Cancer 2014). Here, using microRNA in situ hybridization, we confirmed that miR-26a levels were elevated in 77 human CRC tissue samples and further investigated the key miR-26a-mediated metabolic regulation elements and signaling pathways in CRC cells through quantitative proteomic dissection combined with cancer cell biology and biochemical loss-of-function analysis. We found that AKT transcription signaling was a target pathway via miR-26a-mediated deacetylation modification of Ras-responsive element-binding protein 1 (RREB1) at the Lys-60 residue. miR-26a improved the deacetylation level of RREB1, thus contributing to RREB1 binding to the AKT1 promoter to activate AKT transcription and its related signaling pathway in glycolysis. Moreover, miR-26a promoted CRC tumorigenesis in CRC cells and subcutaneous xenograft mice. Thus, miR-26a is a key regulator of CRC tumorigenesis that mediates the deacetylation modification of RREB1 to enhance AKT1 transcription and downstream target gene expression in glycolysis for CRC growth.

PDK1 Inhibitor BX795 Improves Cisplatin and Radio-Efficacy in Oral Squamous Cell Carcinoma by Downregulating the PDK1/CD47/Akt-Mediated Glycolysis Signaling Pathway.

Background: Oral squamous cell carcinoma (OSCC) has a high prevalence and predicted global mortality rate of 67.1%, necessitating better therapeutic strategies. Moreover, the recurrence and resistance of OSCC after chemo/radioresistance remains a major bottleneck for its effective treatment. Molecular targeting is one of the new therapeutic approaches to target cancer. Among a plethora of targetable signaling molecules, PDK1 is currently rising as a potential target for cancer therapy. Its aberrant expression in many malignancies is observed associated with glycolytic re-programming and chemo/radioresistance. Methods: Furthermore, to better understand the role of PDK1 in OSCC, we analyzed tissue samples from 62 patients with OSCC for PDK1 expression. Combining in silico and in vitro analysis approaches, we determined the important association between PDK1/CD47/LDHA expression in OSCC. Next, we analyzed the effect of PDK1 expression and its connection with OSCC orosphere generation and maintenance, as well as the effect of the combination of the PDK1 inhibitor BX795, cisplatin and radiotherapy in targeting it. Results: Immunohistochemical analysis revealed that higher PDK1 expression is associated with a poor prognosis in OSCC. The immunoprecipitation assay indicated PDK1/CD47 binding. PDK1 ligation significantly impaired OSCC orosphere formation and downregulated Sox2, Oct4, and CD133 expression. The combination of BX795 and cisplatin markedly reduced in OSCC cell’s epithelial-mesenchymal transition, implying its synergistic effect. p-PDK1, CD47, Akt, PFKP, PDK3 and LDHA protein expression were significantly reduced, with the strongest inhibition in the combination group. Chemo/radiotherapy together with abrogation of PDK1 inhibits the oncogenic (Akt/CD47) and glycolytic (LDHA/PFKP/PDK3) signaling and, enhanced or sensitizes OSCC to the anticancer drug effect through inducing apoptosis and DNA damage together with metabolic reprogramming. Conclusions: Therefore, the results from our current study may serve as a basis for developing new therapeutic strategies against chemo/radioresistant OSCC.

Genital Chlamydia trachomatis infection and infertility in Malaysia

Background: Genital Chlamydia trachomatis infection can cause pelvic inflammatory disease and infertility in female by damaging cervical columnar epithelial cells. Recent reports have shown increased cases of newly reported chlamydial infection worldwide. However, at present, there is no effective vaccine available for the prevention of genital chlamydial infection. Insights into the host response of the human cervical epithelial cells against C. trachomatis infection are crucial to design a better prevention and vaccination strategy. Methods and materials: Here, we examined the prevalence of the C. trachomatis infection and the association with women's health in Malaysia. To investigate the influence of the C. trachomatis infection on human epithelial cells, we applied isobaric tags for relative and absolute quantitation (iTRAQ) labeling technique and liquid chromatography-tandem mass spectrometry (LC-MS3) analysis for elucidation of host proteome changes in the C. trachomatis-infected HeLa-229 human cervical epithelial cells. In addition, cytokine response following stimulation with multiple C. trachomatis antigens (CPAF, HSP60 and MOMP) were also examined. Results: Here, we reported that the prevalence of genital chlamydial infection among the ostetrics and gynecology patients was alarmingly high at 51.1% (92/180). Our data also showed that genital C. trachomatis infection was associated with infertility issues, inflammation in the reproductive tract (mucopurulent cervicitis or endometriosis), irregular menstrual cycles and polycystic ovarian syndrome (PCOS). Our proteomic work discovered a significant array of host proteins which participated in the early C. trachomatis infection. We highlighted involvement of eukaryotic initiation factor 2 (eIF2), mammalian target of rapamycin (mTOR), ubiquitination, clathrin-mediated endocytosis, tRNA charging and glycolysis signaling pathways in the host cells to eradicate the bacteria invasion. The bacteria infection was also associates with other complications such as increased inflammation and pro-inflammatory cytokines (TNF-α, IL-1β and IL-6) were robustly secreted following antigenic exposure. Conclusion: Our study describes a high prevalence of C. trachomatis among Malaysian O&G patients and highlights distinct ability of C. trachomatis in manipulating host proteins and triggering pro-inflammatory response.

EZH2 is a negative prognostic biomarker associated with immunosuppression in hepatocellular carcinoma.

The enhancer of zeste homolog 2 (EZH2) plays a critical role in different components of anti-tumor immunity. However, the specific role of EZH2 in modulating MHC Class I antigen presentation and T cell infiltration have not been investigated in HCC. This study analyzed the expression and clinical significance of EZH2 in HCC. The EZH2 genetic alterations were identified using cBioPortal. The EZH2 mRNA and protein levels were found to be significantly higher in HCC than in adjacent normal liver tissues in multiple datasets from the GEO and TCGA databases. High expression of EZH2 was significantly correlated with poor overall survival, disease-specific survival, progression-free survival, and relapse-free survival in almost all patients with HCC. The gene set variance analysis (GSVA) showed that the expression of EZH2 is positively correlated with an immunosuppressive microenvironment and negatively correlated with major MHC class I antigen presentation molecules. Gene set enrichment analysis (GSEA) showed that high EZH2 expression is positively associated with the MYC and glycolysis signaling pathway and negatively associated with the interferon-gamma signaling pathway in HCC tissues. These findings demonstrate that EZH2 is a potential prognostic biomarker and therapeutic target in HCC.

Cytotoxic Screening and Transcriptomics Reveal Insights into the Molecular Mechanisms of Trihexyl Phosphate-Triggered Hepatotoxicity.

Mounting evidence shows that organophosphate flame retardants (OPFRs), especially aryl- and halogenated-OPFRs, exert various adverse health effects on living organisms. This study evaluated the hepatotoxic effect of trihexyl phosphate (THP) as a long-chain alkyl-OPFR on human hepatocyte cells (LO2) and mouse hepatocyte cells (AML12) by performing screening of cytotoxicity in vitro. In combination with transcriptomic analysis, toxicological mechanisms in vitro were further investigated. Results showed that THP triggered hepatotoxicity in vitro by altering four signaling pathways: endoplasmic reticulum (ER) stress, apoptosis, cell cycle, and the glycolysis signaling pathway. Exposure of LO2 and AML12 liver cells to THP (25 μg/mL) significantly induced ER stress-mediated apoptosis and cell cycle arrest. Meanwhile, downregulation of glycolysis caused the blockage of energy metabolism. Furthermore, the high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (HPLC-Q-TOF-MS/MS) revealed that much of THP was absorbed into the cells and displayed stability in the two liver cell lines. In vivo assays using a mouse model demonstrated that exposure to THP at 400 mg/kg induced the ballooning degeneration of hepatocytes in liver tissue, whereas exposure to THP at 800 mg/kg caused acute liver injury with high alanine aminotransferase levels. This study provides novel insights into the impact of THP on hepatotoxicity in vitro and in vivo and uncovers the underlying toxicological mechanisms, which may serve as a guide for further ecological risk assessment and reasonable application of alkyl-OPFRs.

Abstract 5353: Single cell RNA sequencing of pancreatic ductal adenocarcinoma reveals tumor heterogeneity

Abstract Background: Pancreatic ductal adenocarcinoma (PDAC) accounts for ~95% of pancreatic cancer cases and is currently the 3rd leading cause of adult cancer deaths in the US. Due to the lack of methods for early detection and limited treatment options, PDAC has a dismal 5-year survival rate at just <9%. The desmoplastic PDAC tumor microenvironment (TME) is complex and heterogeneous. With recent advances in technology, the characterization of tumors to investigate cellular diversity and evolution in cancer is rapidly accelerating. Here we employed single cell RNA sequencing (scRNA-Seq) to profile transcriptomes of individual cells from dissociated pancreatic tumors isolated from either patients or transgenic mice developing spontaneous PDAC (KPC). This approach elucidated the cellular makeup of individual tumor to reveal distinct cell types like epithelial, endothelial and immune cells, cancer associated fibroblasts (CAFs) and cells undergoing epithelial-to-mesenchymal transition (EMT). Deregulated pathways specific to distinctly identified cell populations were also mapped. Methods: Freshly harvested human or mouse PDAC tumors were mechanically and enzymatically dissociated to single cells using a Miltenyi gentleMACS Tissue Dissociator. The 10X Genomics Chromium Single Cell 3′ Solution was employed for capture, amplification and labeling of mRNA from single cells and for library preparation. scRNA-Seq was performed on Illumina HiSeq 2500. Custom R packages were used for clustering and bioinformatics data analyses. Results: Viability of single cell suspensions used for library preps from all samples was >81%. By unsupervised clustering of the scRNA-Seq matrix and using known signature genes for various cell types we revealed the cellular heterogeneity in a human PDAC to identify distinct cell types. These included epithelial tumor cells (EPCAM+, KRT19+); CD133+ tumor stem cells; CAFs (COL5A1+, COL6A2+, SPARC+); endothelial cells CDH5+ VWF+; and CD45 (PTPRC)+ immune cells also positive for CD3D, CD2, FCGR2A; and cells undergone EMT (CDH2+, ITGA5+, SNAI2+). Using a similar strategy, mouse PDAC diversity was represented by epithelial and EMT tumor cells, CAFs, endothelial cells, macrophages and MDSCs. KRAS and glycolysis signaling pathways in epithelial tumor cells, while hypoxia in the EMT cluster were up regulated. KPC tumors differed in the extent of immune cell infiltration, with a low influx in the smaller versus large tumor, both perhaps representing distinct stages of tumor progression. Conclusions: Our data supports high throughput scRNA-Seq of solid tumors like PDAC as a powerful method to probe and elucidate the underlying tumor heterogeneity. Understanding diversity and complexity of the PDAC TME in individual tumors may help identify unique therapeutic targets and potentially inform treatment/maintenance strategies for patients with advanced disease. Citation Format: Pawan Noel, Wei Lin, Erkut Borazanci, Albert Amini, Ruben Muñoz, Emily Rodela, Serina Ng, Daniel Von Hoff, Haiyong Han. Single cell RNA sequencing of pancreatic ductal adenocarcinoma reveals tumor heterogeneity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5353.

Metabolic Signature of Pluripotent Stem Cells.

Objective Pluripotent stem cells (PSCs), with the capacity to self-renew and differentiate into all other cell types, are of benefit in regenerative medicine applications. Tightly controlled gene expression networks and epigenetic factors regulate these properties. In this study, we aim to evaluate the metabolic signature of pluripotency under 2i and R2i culture conditions versus serum condition. Materials and Methods In this experimental study, we investigated bioinformatics analysis of the shotgun proteomics data for cells grown under 2i, R2i, and serum culture conditions. The findings were validated by cell cycle analysis and gene expressions of the cells with flow cytometry and quantitative reverse transcription-polymerase chain reaction (qRT-PCR), respectively. Results Expressions of 163 proteins increased in 2i-grown cells and 181 proteins increased in R2i-grown cells versus serum, which were mostly involved in glycolysis signaling pathway, oxidation-reduction, metabolic processes, amino acid and lipid metabolism. Flow cytometry analysis showed significant accumulation of cells in S phase for 2i (70%) and R2i (61%) grown cells. ConclusionThis study showed that under 2i and R2i conditions, glycolysis was highlighted for energy production and used to maintain high levels of glycolytic intermediates to support cell proliferation. Cells grown under 2i and R2i conditions showed rapid cell cycling in comparison with the cells grown under serum conditions.

Sensitization of hepatocellular carcinoma cells to irradiation by miR‑34a through targeting lactate dehydrogenase‑A.

Radiation is a therapeutic strategy for the treatment of cancer, and is also used for the treatment of hepatocellular carcinoma. MicroRNAs (miRs) are endogenous, non‑coding single‑stranded RNA molecules, which regulate gene expression at the post‑transcriptional level. In the present study, the roles of miR‑34a‑mediated glycolysis in radiation sensitivity were investigated. By establishing a radioresistant liver cancer cell line, the present study compared the expression level of miR‑34a from radiosensitive and radioresistant cells using the reverse transcription‑quantitative polymerase chain reaction. The glucose uptake and lactate production were also compared between the two types of cells. The results demonstrated that miR‑34a acted as a tumor suppressor in human hepatocellular cancer cells. Following comparison of radiosensitive and radioresistant cancer cells, the results of the present study demonstrated that miR‑34a was negatively correlated with radiation resistance; and levels of miR‑34a were significantly downregulated in the HepG2 radioresistant cells. Furthermore, the rate of glycolysis in the radioresistant cells was elevated, and there was evidence that glucose uptake and lactate production increased. Lactate dehydrogenase A (LDHA), which is a key enzyme in the glycolysis signaling pathway, was found to be a target of miR‑34a in hepatocellular cancer cells. Notably, the overexpression of miR‑34a re‑sensitized HepG2 radioresistant cells to radiation treatment by inhibiting LDHA. The results of the present study revealed a negative correlation between miR‑34a and glycolysis, caused by the targeting of LDHA‑34a, providing a novel mechanism for miR‑34a‑mediated radioresistance.

Molecular mechanism of acute radiation enteritis revealed using proteomics and biological signaling network analysis in rats.

Radiation enteritis (RE) has emerged as a significant complication that can progress to severe gastrointestinal disease and the mechanisms underlying its genesis remain poorly understood. The aim of this study was to identify temporal changes in protein expression potentially associated with acute inflammation and to elucidate the mechanism underlying radiation enteritis genesis. Male Sprague-Dawley rats were irradiated in the abdomen with a single dose of 10Gy to establish an in vivo model of acute radiation enteritis. Two-dimensional fluorescence difference gel electrophoresis, matrix-assisted laser desorption/ionization time-of-flight spectrometer (MALDI-TOF) tandem mass spectrometry, and peptide mass fingerprinting were used to determine differentially expressed proteins between normal and inflamed intestinal mucosa. Additionally, differentially expressed proteins were evaluated by KO Based Annotation System to find the biological functions associated with acute radiation enteritis. Intensity changes of 86 spots were detected with statistical significance (ratio≥1.5 or≤1.5, P<0.05). Sixty one of the 86 spots were identified by MALDI-TOF/TOF tandem mass spectrometry. These radiation-induced proteins with biological functions showed that the FAS pathway and glycolysis signaling pathways were significantly altered using the KOBAS tool. Our results reveal an underlying mechanism of radiation-induced acute enteritis, which may help clarify the pathogenesis of RE and point to potential targets for therapeutic interventions.