ENO1 promotes trophoblast invasion regulated by E2F8 in recurrent miscarriage.

Recurrent miscarriage (RM) is related to the dysfunction of extravillous trophoblast cells (EVTs), but the comprehensive mechanisms remain largely unexplored. We analyzed single-cell RNA sequencing (scRNA-seq), bulk RNA sequencing and microarray datasets obtained from Gene Expression Omnibus (GEO) database to explore the hub genes in the mechanisms of RM. We identified 1724 differentially expressed genes (DEGs) in EVTs from the RM, and they were all expressed along the trajectory of EVTs. These DEGs were associated with hypoxia and glucose metabolism. Single-cell Regulatory Network Inference and Clustering (SCENIC) analysis revealed that E2F transcription factor (E2F) 8 (E2F8) was a key transcription factor for these DEGs. And the expression of ENO1 can be positively regulated by E2F8 via RNA sequencing analysis. Subsequently, we performed immunofluorescence assay (IF), plasmid transfection, western blotting, chromatin immunoprecipitation (ChIP), real-time quantitative polymerase chain reaction (qRT-PCR), and transwell assays for validation experiments. We found that the expression of alpha-Enolase 1 (ENO1) was lower in the placentas of RM. Importantly, E2F8 can transcriptionally regulate the expression of ENO1 to promote the invasion of trophoblast cells by inhibiting secreted frizzled-related protein 1/4 (SFRP1/4) to activate Wnt signaling pathway. Our results suggest that ENO1 can promote trophoblast invasion via an E2F8-dependent manner, highlighting a potential novel target for the physiological mechanisms of RM.

ENO1 contributes to the gemcitabine resistance of pancreatic cancer through the YAP1 signaling pathway.

Pancreatic cancer (PC), a leading cause of cancer-related deaths, has a 5-year survival rate of approximately 10%. α-Enolase (ENO1) is a junction channel protein involved in tumor cell apoptosis and chemoresistance. However, the role of ENO1 in PC remains unclear. The expression and prognosis of ENO1 levels were determined in PC using public databases based on The Cancer Genome Atlas (TCGA) data sets. Cell viability, half maximal inhibitory concentration (IC50), autophagy, apoptosis, and autophagy markers were examined using cell counting kit-8 (CCK-8), transmission electron microscope, flow cytometry assays, and immunoblot, respectively. Using the Gene Expression Omnibus (GEO) and TCGA data sets, we found that ENO1 was significantly enriched in PC tumor tissues, and high expression levels of ENO1 were associated with an unfavorable prognosis. Whereas ENO1 silencing suppressed proliferation, autophagy, and induced cell apoptosis in PC cells, and inhibited tumor growth in vivo. Mechanistically, knockdown of ENO1 enhanced cellular cytotoxicity of gemcitabine (GEM), as well as reducing the expression of yes-associated protein 1 (YAP1), a major downstream effector of the Hippo pathway in vitro. YAP1 promoted autophagy and protected PC cells from GEM-induced apoptotic cell death. Furthermore, YAP1 overexpression attenuated the inhibition effects of ENO1 silencing. Our results suggest that ENO1 overexpression promotes cell growth and tumor progression by increasing the expression of YAP1 in PC. Further studies are required to understand the detailed mechanisms between ENO1 and YAP1 in PC.

A Circular RNA, hsa_circ_0018180 (circPARD3), Triggers Glycolysis and Promotes Malignancy of Head and Neck Squamous Cell Carcinoma Through the miR-5194/ENO1 Axis.

Emerging evidence has demonstrated the pivotal roles of circular RNAs (circRNAs) in the modulation of malignancy and pathological progression among multiple human cancers. Glucose metabolism reprogramming is a widely identified characteristic for contributing to facilitate tumorigenesis. Nonetheless, their contributions to head and neck squamous cell carcinoma (HNSCC) cell glycolysis remain to be further elucidated. Herein, we aim to investigate the role of circRNA, hsa_circ_0018180 (also named as circPARD3) in HNSCC. Expression patterns of circPARD3 in HNSCC tissues and different cell lines were determined by qRT-PCR assay, as well as its correlation with the prognosis of survival. CCK-8, EdU incorporation, and transwell assays were carried out to assess the cell viability, proliferation, migration, and invasion, respectively. Glucose uptake and lactate production were evaluated by preforming glycolysis. Mechanistically, the circPARD3/miR-5194/ENO1 axis was verified by RNA immunoprecipitation (RIP) and luciferase reporter assays. Western blot analysis was employed to measure the epithelial-mesenchymal transition (EMT)-associated biomarkers. Upregulated circPARD3 observed in HNSCC tissues and cell lines indicated the poor prognosis of patients. Stable knockdown of circPARD3 dramatically exerted the suppressive effects on cell viability, proliferation, migration, and invasion, as well as glucose uptake and lactate production. Mechanistically, circPARD3 harbored miR-5194, serving as a miRNA sponge, thereby increasing ENO1 expression. Moreover, ENO1 evidently reversed miR-5194-mediated attenuated malignant behaviors. Collectively, our study identified an oncogenic role of circPARD3 in HNSCC through a novel machinery of circPARD3/miR-5194/ENO1 and provided a promising therapeutic target for HNSCC.

Determination of the Predictive Roles and Potentially Pathogenic Antigen Epitopes of α-Enolase Related to the Development of Miscarriage in Females with Autoimmune Thyroiditis.

Autoimmune thyroiditis (AIT) is a common endocrine disease which causes a significantly increased risk of miscarriage. Our recent study has shown that the increased ENO1 autoantibody (ENO1Ab) expression in an experimental AIT mouse model was induced by thyroglobulin (Tg) immunization only. In this study, we explored the potential roles of ENO1Ab in miscarriage occurrence among AIT women, and the specific epitopes of ENO1 targeted by ENO1Ab. A total of 432 euthyroid pregnant participants were selected from the project of Subclinical Hypothyroid during Early Pregnancy, including 48 women with AIT and miscarriage, 96 with miscarriage but no AIT, 96 with AIT but no miscarriage, and 192 without either AIT or miscarriage. The enzyme-linked immunosorbent assay was used to determine the serum levels of total IgG against ENO1 and 18 predicted antigen epitopes of ENO1. The results showed that women with AIT and miscarriage had the highest serum levels of ENO1Ab compared to the other groups. Logistic regression analysis showed that the serum ENO1Ab was an independent risk factor for miscarriage, especially among AIT females. The serum level of total IgG against the predicted epitope peptide 6 (i.e., P6 and aa168-183) of ENO1 was significantly increased in women with AIT and miscarriage when compared with those of both the AIT non-miscarriage group and non-AIT miscarriage group. This pilot study suggests that serum ENO1Ab may have a fair predictive value for AIT-related miscarriage, and the autoantibody specific to P6 epitope may especially be more specifically related to this disorder.

Evaluating the Anti-Melanoma Effects and Toxicity of Cinnamaldehyde Analogues.

Cinnamaldehyde (CA) showed potent activity against melanoma in our previous study, and the structure of unsaturated aldehydes is envisaged to play a role. Nevertheless, its limited drug availability restricts its clinical application. Therefore, a series of CA analogues were synthesized to evaluate their anti-melanoma activities across various melanoma cell lines. These compounds were also tested for their toxicity against the different normal cell lines. The compound with the most potential, CAD-14, exhibited potent activity against the A375, A875 and SK-MEL-1 cells, with IC50 values of 0.58, 0.65, and 0.82 µM, respectively. A preliminary molecular mechanism study of CAD-14 indicated that it could inhibit the p38 pathway to induce apoptosis, and suppress tumor growth by inhibiting the expression of ENO1. Furthermore, an acute toxicity study depicted that CAD-14 has better safety and tolerability than CA in vivo. These findings indicate that CAD-14 might be a lead compound for exploring effective anti-melanoma drugs.

Identification of alpha-enolase as a potential immunogenic molecule during allogeneic transplantation of human adipose-derived mesenchymal stromal cells.

BACKGROUND AIMS: Given their low immunogenicity, immunoregulatory effects and multiple differentiation capacity, mesenchymal stromal cells (MSCs) have the potential to be used for "off-the-shelf" cell therapy to treat various diseases. However, the allorejection of MSCs indicates that they are not fully immune-privileged. In this study, the authors investigated the immunogenicity of human adipose-derived MSCs (Ad-MSCs) and identified potential immunogenic molecules. METHODS: To evaluate the immunogenicity of human Ad-MSCs in vivo, cells were transplanted into humanized mice (hu-mice), then T-cell infiltration and clearance of human Ad-MSCs were observed by immunofluorescence and bioluminescence imaging. One-way mixed lymphocyte reaction and flow cytometry were performed to evaluate the immunogenicity of human Ad-MSCs in vitro. High-throughput T-cell receptor (TCR) repertoire sequencing and mass spectrometry were applied to identified potential immunogenic molecules. RESULTS: The authors observed that allogeneic Ad-MSCs recruited human T cells and caused faster clearance in hu-mice than non-humanized NOD.Cg-Prkdcscid IL2rgtm1Wjl/SzJ (NSG) mice. The proliferation and activation of T cells were significantly enhanced during in vitro co-culture with human Ad-MSCs. In addition, the level of HLA-II expression on human Ad-MSCs was dramatically increased after co-culture with human peripheral blood mononuclear cells (PBMCs). High-throughput sequencing was applied to analyze the TCR repertoire of the Ad-MSC-recruited T cells to identify dominant TCR CDR3 sequences. Using synthesized TCR CDR3 peptides, the authors identified several potential immunogenic candidates, including alpha-enolase (ENO1). The ENO1 expression level of Ad-MSCs significantly increased after co-culture with PBMCs, whereas ENO1 inhibitor (ENOblock) treatment decreased the expression level of ENO1 and Ad-MSC-induced proliferation of T cells. CONCLUSIONS: The authors' findings improve the understanding of the immunogenicity of human Ad-MSCs and provide a theoretical basis for the safe clinical application of allogeneic MSC therapy.

An auto-antibody identified from phenotypic directed screening platform shows host immunity against EV-A71 infection.

BACKGROUND: Enterovirus A71 (EV-A71) is a neurotropic virus which may cause severe neural complications, especially in infants and children. The clinical manifestations include hand-foot-and-mouth disease, herpangina, brainstem encephalitis, pulmonary edema, and other severe neurological diseases. Although there are some vaccines approved, the post-marketing surveillance is still unavailable. In addition, there is no antiviral drugs against EV-A71 available. METHODS: In this study, we identified a novel antibody that could inhibit viral growth through a human single chain variable fragment (scFv) library expressed in mammalian cells and panned by infection with lethal dose of EV-A71. RESULTS: We identified that the host protein α-enolase (ENO1) is the target of this scFv, and anti-ENO1 antibody was found to be more in mild cases than severe EV-A71 cases. Furthermore, we examined the antiviral activity in a mouse model. We found that the treatment of the identified 07-human IgG1 antibody increased the survival rate after virus challenge, and significantly decreased the viral RNA and the level of neural pathology in brain tissue. CONCLUSIONS: Collectively, through a promising intracellular scFv library expression and screening system, we found a potential scFv/antibody which targets host protein ENO1 and can interfere with the infection of EV-A71. The results indicate that the usage and application of this antibody may offer a potential treatment against EV-A71 infection.

α-Enolase inhibits apoptosis and promotes cell invasion and proliferation of skin cutaneous melanoma.

BACKGROUND: The glycolytic enzyme, α-Enolase (ENO1), catalyzes the production of phosphoenolpyruvate from 2-phosphoglycerate, thereby enhancing glycolysis and contributing to tumor progression. In the present study, we aimed to determine the role of ENO1 in skin cutaneous melanoma (SKCM) and the potential underlying mechanism. METHODS: The Sangerbox database was used to analyze the mRNA expression of ENO1 in SKCM. Western blotting was used to assess the levels of ENO1, c-Myc, ß-catenin, MMP-9, PGAM1, and MMP-13 in SKCM-derived cell lines or tumor tissues from patients with SKCM. The pCMV-SPORT6-ENO1 and pET-28a-ENO1siRNA plasmids were used to overexpress and knockdown ENO1 in SKCM cells, respectively. To determine the function of ENO1 in the malignant behavior of SKCM cells, we performed a wound-healing assay, cell counting kit 8 assay, and transwell chamber analyses. The production of pyruvate and lactic acid in tumor cells was evaluated using their respective kits. RESULTS: Compared with non-tumor tissues, ENO1 was found to be overexpressed in SKCM tissues. In SKCM cells, ENO1 overexpression promoted invasion, migration, and proliferation of tumor cells; increased pyruvate and lactate production; and increased ß-catenin, MMP-9, MMP-13, and c-Myc levels. The opposite effects were observed in SKCM cells silenced for ENO1. CONCLUSIONS: These results indicate that ENO1 is involved in SKCM progression by enhancing the invasion and proliferation of tumor cells. In addition, ENO1 might have an important function in tumor cell glycolysis. Therefore, ENO1 represents a potential therapeutic target for treatment of SKCM.

ENO1 Binds to ApoC3 and Impairs the Proliferation of T Cells via IL-8/STAT3 Pathway in OSCC.

Lymph node metastasis is associated with poor prognosis of oral squamous cell carcinoma (OSCC), and few studies have explored the relevance of postoperative lymphatic drainage (PLD) in metastatic OSCC. Alpha-enolase (ENO1) is a metabolic enzyme, which is related to lymphatic metastasis of OSCC. However, the role of ENO1 in PLD in metastatic OSCC has not been elucidated. Herein, we collected lymphatic drainage after lymphadenectomy between metastatic and non-metastatic lymph nodes in OSCC patients to investigate the relationship between ENO1 expression and metastasis, and to identify the proteins which interacted with ENO1 in PLD of patients with metastatic OSCC by MS/GST pulldown assay. Results revealed that the metabolic protein apolipoprotein C-III (ApoC3) was a novel partner of ENO1. The ENO1 bound to ApoC3 in OSCC cells and elicited the production of interleukin (IL)-8, as demonstrated through a cytokine antibody assay. We also studied the function of IL-8 on Jurkat T cells co-cultured with OSCC cells in vitro. Western blot analysis was applied to quantitate STAT3 (signal transducer and activator of transcription 3) and p-STAT3 levels. Mechanistically, OSCC cells activated the STAT3 signaling pathway on Jurkat T cells through IL-8 secretion, promoted apoptosis, and inhibited the proliferation of Jurkat T cells. Collectively, these findings illuminate the molecular mechanisms underlying the function of ENO1 in metastasis OSCC and provide new strategies for targeting ENO1 for OSCC treatment.

[Relationship between anti-ENO1 antibody and systemic lupus erythematosus patients with retinopathy].

OBJECTIVE: To build bridges between anti-α enolase antibody (anti-enolase 1 antibody, anti-ENO1 antibody) and common clinical and laboratory characteristics of systemic lupus erythematosus (SLE) and to analyze the role of anti-ENO1 antibody in the evaluation of SLE disease activity. METHODS: The SLE patients with retinopathy and without retinopathy were enrolled in the study, as well as healthy individuals whose gender and age matched with those of the SLE patients. Serum anti-ENO1 antibodies were measured using enzyme-linked immunosorbent assay (ELISA), presenting as intra-group positive rate and arbitrary units (AU) value. Clinical and laboratory data were obtained from medical records. RESULTS: The SLE retinopathy patients represented various fundus abnormalities. Ranked by percentage, the top three retinopathies were retinal hemorrhage (14/32, 43.75%), cotton-wool spots (8/32, 25.00%) and retinal vein occlusion (3/32, 9.38%). Among the 32 SLE retinopathy patients, 13 (40.63%) suffered from two or more fundus abnormalities. The positive rate and AU value of the SLE patients were higher than of the SLE patients without retinopathy (68.75% vs. 46.00%, P=0.043; 16.11%±10.35% vs. 12.06%±6.47%, P=0.045). Besides, the positive rate and AU value of the two SLE groups were both significantly higher than those of the healthy control group (P < 0.001). Compared with the SLE-without-retinopathy group, the systemic lupus erythematosus disease activity index (SLEDAI)-2000 of the SLE retinopathy patients were significantly higher than those of the SLE patients without retinopathy (17.41±4.25 vs. 9.48±5.35, P < 0.001). Dividing all the SLE patients into an anti-ENO1-positive group and an anti-ENO1-negative group, we found that anti-ENO1-positive was more likely to be correlated to developing fever and positive result of urine occult blood (P=0.011, P=0.042). Comparing with the patients with negative anti-ENO1 antibodies, the patients with positive anti-ENO1 antibodies had significantly higher erythrocyte sedimentation rate (ESR) [the median (range) was 29.50 (1.52-110.00) mg/L vs. 12.00 (4.00-101.00) mg/L, P=0.001], higher immunoglobulin G (IgG) [the median (range) was 14.30 (4.02-37.80) g/L vs. 10.46 (2.50-25.73) g/L, P=0.000 3], and higher blood platelet count (PLT) [(205.87×109±67.98×109) /L vs. (164.57×109±69.57×109) /L, P=0.008], as well as higher immunoglobulin A (IgA) [the median (range) was 2.85 (0.07-27.00) g/L vs. 2.05 (0.42-4.36) g/L, P=0.014]. CONCLUSION: The positive rate and AU value of anti-ENO1 antibody suggested higher SLE disease activity and they were elevated in SLE and SLE retinopathy.

Aspirin modulates 2-hydroxyisobutyrylation of ENO1K281 to attenuate the glycolysis and proliferation of hepatoma cells.

Aspirin can efficiently inhibit the glycolysis and proliferation of cancer cells, however, the underlying mechanism is poorly understood. Here, we report that aspirin attenuates the glycolysis and proliferation of hepatoma cells through modulating the levels of lysine 2-hydroxyisobutyrylation (Khib) of enolase 1 (ENO1). We found that aspirin decreased the levels of glucose consumption and lactate production in hepatoma cells. Moreover, 4 mM aspirin reduced the activities of ENO1, a key enzyme of glycolysis, and decreased the levels of ENO1 Khib in the cells. Interestingly, we identified that 4 mM aspirin could decrease the levels of Khib on many proteins by using pan Khib antibody in the cells. Interestingly, the activities of ENO1 could be rescued by the transient overexpression of ENO1, but not by ENO1 mutant (K281R). Moreover, we identified that the C646, an inhibitor of p300 which is a writer of Khib, could reduce the levels of ENO1 Khib, resulting in the decrease of ENO1 activities. The treatment with PDTC, an inhibitor of NF-κB which is a target of aspirin, could work well as C646 in the cells. Both of aspirin and C646 (or PDTC) displayed a stronger effect than the single treatment in the system. Functionally, ENO1, but not ENO1 mutant (K281R), could rescue the aspirin-induced inhibition of proliferation of liver cancer cells in vitro, suggesting that ENO1K281 is involved in the aspirin-mediated inhibition of liver cancer. Our finding provides new insights into the mechanism by which aspirin attenuates the glycolysis and proliferation of hepatoma cells.

Serum IgG2 antibody multicomposition in systemic lupus erythematosus and lupus nephritis (Part 1): cross-sectional analysis.

OBJECTIVES: Serum anti-dsDNA and anti-nucleosome IgGs have been proposed as signatures for SLE and LN in limited numbers of patients. We sought to show higher sensitivity and specificity of the same antibodies with the IgG2 isotype and included IgG2 antibodies vs specific intracellular antigens in the analysis. METHODS: A total of 1052 SLE patients with (n = 479) and without (n = 573) LN, recruited at different times from the beginning of symptoms, were included in the study. Patients with primary APS (PAPS, n = 24), RA (RA, n = 24) and UCTD (UCTD, n = 96) were analysed for comparison. Anti-nucleosome (dsDNA, Histone2A, Histone3), anti-intracellular antigens (ENO1), anti-annexin A1 and anti-C1q IgG2 were determined by non-commercial techniques. RESULTS: The presence in the serum of the IgG2 panel was highly discriminatory for SLE/LN vs healthy subjects. Serum levels of anti-dsDNA and anti-C1q IgG2 were more sensitive than those of IgGs (Farr radioimmunoassay/commercial assays) in identifying SLE patients at low-medium increments. Of more importance, serum positivity for anti-ENO1 and anti-H2A IgG2 discriminated between LN and SLE (ROC T0-12 months), and high levels at T0-1 month were detected in 63% and 67%, respectively, of LN, vs 3% and 3%, respectively, of SLE patients; serum positivity for each of these was correlated with high SLEDAI values. Minor differences existed between LN/SLE and the other rheumatologic conditions. CONCLUSION: Nephritogenic IgG2 antibodies represent a specific signature of SLE/LN, with a few overlaps with other rheumatologic conditions. High levels of anti-ENO1 and anti-H2A IgG2 correlated with SLE activity indexes and were discriminatory between SLE patients limited to the renal complication and other SLE patients. TRIAL REGISTRATION: The Zeus study was registered at https://clinicaltrials.gov, NCT02403115.

Serum IgG2 antibody multi-composition in systemic lupus erythematosus and in lupus nephritis (Part 2): prospective study.

OBJECTIVES: Circulating anti-ENO1 and anti-H2A IgG2 have been identified as specific signatures of LN in a cross-over approach. We sought to show whether the same antibodies identify selected population of patients with LN with potentially different clinical outcomes. METHODS: Here we report the prospective analysis over 36 months of circulating IgG2 levels in patients with newly diagnosed LN (n=91) and SLE (n=31) and in other patients with SLE recruited within 2 years from diagnosis (n=99). Anti-podocyte (ENO1), anti-nucleosome (DNA, histone 2 A, histone 3) and anti-circulating proteins (C1q, AnnexinA1-ANXA1) IgG2 antibodies were determined by home-made techniques. RESULTS: LN patients were the main focus of the study. Anti-ENO1, anti-H2A and anti-ANXA1 IgG2 decreased in parallel to proteinuria and normalized within 12 months in the majority of patients while anti-dsDNA IgG2 remained high over the 36 months. Anti-ENO1 and anti-H2A had the highest association with proteinuria (Heat Map) and identified the highest number of patients with high proteinuria (68% and 71% respectively) and/or with reduced estimated glomerula filtration rate (eGFR) (58% for both antibodies) compared with 23% and 17% of anti-dsDNA (agreement analysis). Anti-ENO1 positive LN patients had higher proteinuria than negative patients at T0 and presented the maximal decrement within 12 months. CONCLUSIONS: Anti-ENO1, anti-H2A and anti-ANXA1 antibodies were associated with high proteinuria in LN patients and Anti-ENO1 also presented the maximal reduction within 12 months that paralleled the decrease of proteinuria. Anti-dsDNA were not associated with renal outcome parameters. New IgG2 antibody signatures should be utilized as tracers of personalized therapies in LN. TRIAL REGISTRATION: The Zeus study was registered at https://clinicaltrials.gov (study number: NCT02403115).

AL355338 acts as an oncogenic lncRNA by interacting with protein ENO1 to regulate EGFR/AKT pathway in NSCLC.

BACKGROUND: Non-small cell lung cancer (NSCLC) is a malignancy with considerable morbidity and mortality. Abnormal metabolism is a hallmark of cancer; however, the mechanism of glycolysis regulation in NSCLC progression is not completely understood. Recent studies suggest that some dysregulated long non-coding RNAs (lncRNAs) play important roles in tumor metabolic reprogramming. METHODS: To identify glycolysis-associated-lncRNAs in NSCLC, we compared RNA-sequencing results between high 18F-fluorodeoxyglucose (FDG)-uptake NSCLC tissues and paired paratumor tissues. The transcript abundance of AL355338 in 80 pairs of clinical samples was evaluated by quantitative real-time PCR assay and fluorescence in situ hybridization. The biological role of AL355338 on NSCLC cells were evaluated by functional experiments in vitro and in vivo. Moreover, RNA pull-down, mass spectrometry and RNA immunoprecipitation (RIP) assays were used to identify the protein interacted with AL355338. Co-immunoprecipitation, in situ proximity ligation assays and western blotting were applied to define the potential downstream pathways of AL355338. RESULTS: AL355338 was an upregulated glycolysis-associated lncRNA in NSCLC. Functional assays revealed that AL355338 was critical for promoting aerobic glycolysis and NSCLC progression. Mechanistic investigations showed that AL355338 directly bound with alpha-enolase (ENO1) and enhanced the protein's stability by modulating its degradation and ubiquitination. A positive correlation was observed between AL355338 and ENO1 in NSCLC, and ENO1 was subsequently confirmed to be responsible for the oncogenic role of AL355338. Furthermore, AL355338 was capable of modulating ENO1/EGFR complex interaction and further activating EGFR-AKT signaling. CONCLUSIONS: This study indicates that AL355338 confers an aggressive phenotype to NSCLC, and targeting it might be an effective therapeutic strategy.

Ubiquitin-specific peptidase 46 promotes tumor metastasis through stabilizing ENO1 in human esophageal squamous cell carcinoma.

Esophageal squamous cell carcinoma (ESCC) has high aggressiveness and poor prognosis, and is the major histological subtype of esophageal cancer in East Asia and East Africa. In this study, we found that USP46, a deubiquitinating enzyme, is overexpressed in clinical ESCC samples, especially in patients with positive lymph node metastasis. Moreover, USP46 enhances the migration and invasion of ESCC cells by mediating the EMT process in vitro, and promotes lymph nodes and lung metastasis of ESCC in vivo. In addition, we found that USP46 is a bona fide deubiquitinating enzyme to stabilize the protein level of ENO1 through deubiquitination. ENO1 protein level was also positively correlated with USP46 in the ESCC samples. In summary, these findings reveal the functional role of USP46 as a deubiquitinating enzyme on ESCC metastasis, providing us a potential therapeutic target for the treatment of ESCC.

Salidroside Induces Apoptosis in Human Gastric Cancer Cells via the Downregulation of ENO1/PKM2/GLUT1 Expression.

Salidroside is reported to have a wide range of pharmacological properties and has been proven to play a key anti-cancer effect. This study investigated the effects of purified salidroside, an ingredient of Rhodiola rosea, on the proliferation of two human gastric cancer cell lines and further investigating its possible molecular mechanisms. We verified that salidroside exerts a dose-dependent inhibitory effect on the proliferation of SGC-7901 and MKN-45 human gastric cancer cells. Moreover, salidroside can induce cell apoptosis, which was accompanied by an increase in nuclear fragmentation. In addition, salidroside inhibited glycolysis, as evidenced by the reduced expression levels of the glycolysis-related enzymes pyruvate kinase isoenzyme M2 (PKM2), enolase 1 (ENO1) and glucose transporter 1 (GLUT1), which could play important roles in the metabolism of gastric cancer cells. Further investigation showed that salidroside exerted potent anti-proliferative effects by inhibiting glycolysis in human gastric cancer cells in vitro. In vivo, xenograft tumors treated with salidroside were significantly smaller than those in the control animals. Therefore, salidroside could be a promising therapeutic prospect in the treatment of gastric cancer.

Identification and functional analysis of senescence-associated secretory phenotype of premature senescent hepatocytes induced by hexavalent chromium.

Hexavalent chromium [Cr(VI)] is a common heavy metal pollutant that can cause a number of human disease, including inflammation and cancer. Senescent cells can secrete a variety of molecules known as senescence-associated secretory phenotype (SASP). Our previous studies have confirmed that Cr(VI) can induce premature senescence in L02 hepatocytes, but the composition and the function of the related SASP are still unknown. In order to understand the components of SASP secreted by senescent L02 hepatocytes under the action of Cr(VI), we applied LC-MS/MS-based label-free protein quantification. We found that three SASP components including Coactosin-like protein 1 (COTL1), Alpha-enolase (ENO1), and Peroxiredoxin 2 (PRDX2) were up-regulated, which were confirmed by western blotting and qRT-PCR. Evidence suggested that SASP may promote the development of tumor through chronic inflammatory response, therefore we identified and analyzed the potential biological functions and signaling pathways of these three SASP components using GO and KEGG methods. The interaction between SASP components was analyzed by STRING, and verified by Co-IP. We also found that ENO1 and PRDX2, which have direct interaction, can inhibit the growth and proliferation of wildtype hepatocytes and premature senescent hepatocytes, but can promote the proliferation and behavioral changes of liver tumor cells. The present study provides valuable clues for elucidation of the carcinogenic mechanism of Cr(VI), especially for further prevention and targeted treatment of Cr(VI)-related cancer.

Effect of oxygen and glucose availability during in vitro maturation of bovine oocytes on development and gene expression.

PURPOSE: Oxygen tension during the in vitro maturation (IVM) of oocytes is important for oocyte developmental competence. A conflict exists in the literature as to whether low oxygen during IVM is detrimental or beneficial to the oocyte. Many research and clinical labs use higher than physiological oxygen tension perhaps believing that low-oxygen tension is detrimental to oocyte development. Other studies show that glucose is important if low-oxygen tension is used during maturation. In this study, we look at the link between low oxygen and glucose availability during IVM to resolve misconceptions around low-oxygen tension during IVM. METHODS: Bovine cumulus oocyte complexes (COCs) were matured at 20% vs 7% oxygen in media containing differing glucose concentrations or varying availability. Cleavage and blastocyst rates were recorded. RT-PCR determined expression levels of metabolic, oxygen, and stress-responsive genes following IVM. RESULTS: Embryo development in 7% oxygen groups with 2.3mM glucose/low glucose availability was lower than 20% oxygen groups. Under 7% oxygen with 5.6mM glucose or higher glucose availability, rates were restored to those seen in 20% oxygen. Expressions of BNIP3, ENO1, GAPDH, and SLC2A1, were upregulated in 7% oxygen/low glucose, compared to 20% oxygen groups. BNIP3 expression was higher in 7% oxygen group with low glucose availability compared to the 20% groups. CONCLUSION: Oocyte developmental competence is negatively impacted following IVM in low oxygen when glucose availability is limited. Glucose concentration and physical culture conditions need to be considered when comparing the effects of different oxygen concentrations during IVM.

FGFRL1 affects chemoresistance of small-cell lung cancer by modulating the PI3K/Akt pathway via ENO1.

Fibroblast growth factor receptor-like 1 (FGFRL1), a member of the FGFR family, has been demonstrated to play important roles in various cancers. However, the role of FGFRL1 in small-cell lung cancer (SCLC) remains unclear. Our study aimed to investigate the role of FGFRL1 in chemoresistance of SCLC and elucidate the possible molecular mechanism. We found that FGFRL1 levels are significantly up-regulated in multidrug-resistant SCLC cells (H69AR and H446DDP) compared with the sensitive parental cells (H69 and H446). In addition, clinical samples showed that FGFRL1 was overexpressed in SCLC tissues, and high FGFRL1 expression was associated with the clinical stage, chemotherapy response and survival time of SCLC patients. Knockdown of FGFRL1 in chemoresistant SCLC cells increased chemosensitivity by increasing cell apoptosis and cell cycle arrest, whereas overexpression of FGFRL1 in chemosensitive SCLC cells produced the opposite results. Mechanistic investigations showed that FGFRL1 interacts with ENO1, and FGFRL1 was found to regulate the expression of ENO1 and its downstream signalling pathway (the PI3K/Akt pathway) in SCLC cells. In brief, our study demonstrated that FGFRL1 modulates chemoresistance of SCLC by regulating the ENO1-PI3K/Akt pathway. FGFRL1 may be a predictor and a potential therapeutic target for chemoresistance in SCLC.

Metabonomics analysis of Zi goose follicular granulosa cells using ENO1 gene expression interference.

The Zi goose is native to North-east China and is noted for its high egg production. Alpha enolase (ENO1) is a glycolytic enzyme which functions as a plasminogen receptor in follicular granulosa cells (FGCs), with several studies showing that FGCs can support follicular development. By transfecting the ENO1 interfering plasmid (shRNA) into FGCs, ENO1 expression in these cells was downregulated, suggesting the successful knock-down of ENO1 in these cells. In this knock-down model, we detected 13 metabolites from FGCs using LC/MS. When compared with the non-coding shRNA (NC) group, the lower level metabolites were (R)-(+)-citronellic acid, altretamine, 3-hydroxycaproic acid, heptadecanoic acid, cholecalciferol vitamin D3, indole, benzoic acid, capric acid, caffeic acid, azelaic acid, 3,4-dihydroxyhydrocinnamic acid and cholic acid, while oleic acid was detected at high levels. To further examine the results of metabolomics, six key metabolites were verified by gas chromatography-mass spectrometry (GC-MS). We found that vitamin D3, indole, benzoic acid, capric acid and cholic acid were significantly downregulated in the shRNA group, while oleic acid was significantly upregulated. This observation was consistent with the metabolomics data. Through these studies, we found that decreased ENO1 levels altered certain metabolite levels in FGCs.