Mitochondrial GSNOR Alleviates Cardiac Dysfunction via ANT1 Denitrosylation.

BACKGROUND: The cardiac-protective role of GSNOR (S-nitrosoglutathione reductase) in the cytoplasm, as a denitrosylase enzyme of S-nitrosylation, has been reported in cardiac remodeling, but whether GSNOR is localized in other organelles and exerts novel effects remains unknown. We aimed to elucidate the effects of mitochondrial GSNOR, a novel subcellular localization of GSNOR, on cardiac remodeling and heart failure (HF). METHODS: GSNOR subcellular localization was observed by cellular fractionation assay, immunofluorescent staining, and colloidal gold particle staining. Overexpression of GSNOR in mitochondria was achieved by mitochondria-targeting sequence-directed adeno-associated virus 9. Cardiac-specific knockout of GSNOR mice was used to examine the role of GSNOR in HF. S-nitrosylation sites of ANT1 (adenine nucleotide translocase 1) were identified using biotin-switch and liquid chromatography-tandem mass spectrometry. RESULTS: GSNOR expression was suppressed in cardiac tissues of patients with HF. Consistently, cardiac-specific knockout mice showed aggravated pathological remodeling induced by transverse aortic constriction. We found that GSNOR is also localized in mitochondria. In the angiotensin II-induced hypertrophic cardiomyocytes, mitochondrial GSNOR levels significantly decreased along with mitochondrial functional impairment. Restoration of mitochondrial GSNOR levels in cardiac-specific knockout mice significantly improved mitochondrial function and cardiac performance in transverse aortic constriction-induced HF mice. Mechanistically, we identified ANT1 as a direct target of GSNOR. A decrease in mitochondrial GSNOR under HF leads to an elevation of S-nitrosylation ANT1 at cysteine 160 (C160). In accordance with these findings, overexpression of either mitochondrial GSNOR or ANT1 C160A, non-nitrosylated mutant, significantly improved mitochondrial function, maintained the mitochondrial membrane potential, and upregulated mitophagy. CONCLUSIONS: We identified a novel species of GSNOR localized in mitochondria and found mitochondrial GSNOR plays an essential role in maintaining mitochondrial homeostasis through ANT1 denitrosylation, which provides a potential novel therapeutic target for HF.

Targeting Microtubules for the Treatment of Heart Disease.

Heart disease remains the leading cause of morbidity and mortality worldwide. With the advancement of modern technology, the role(s) of microtubules in the pathogenesis of heart disease has become increasingly apparent, though currently there are limited treatments targeting microtubule-relevant mechanisms. Here, we review the functions of microtubules in the cardiovascular system and their specific adaptive and pathological phenotypes in cardiac disorders. We further explore the use of microtubule-targeting drugs and highlight promising druggable therapeutic targets for the future treatment of heart diseases.

STAT3 as a mediator of oncogenic cellular metabolism: Pathogenic and therapeutic implications.

The oncogenic transcription factor signal transducer and activator of transcription 3 (STAT3) is activated constitutively in a wide array of human cancers. It is an appealing molecular target for novel therapy as it directly regulates expression of genes involved in cell proliferation, survival, angiogenesis, chemoresistance and immune responsiveness. In addition to these well-established oncogenic roles, STAT3 has also been found to mediate a wide array of functions in modulating cellular behavior. The transcriptional function of STAT3 is canonically regulated through tyrosine phosphorylation. However, STAT3 phosphorylated at a single serine residue can allow incorporation of this protein into the inner mitochondrial membrane to support oxidative phosphorylation (OXPHOS) and maximize the utility of glucose sources. Conflictingly, its canonical transcriptional activity suppresses OXPHOS and favors aerobic glycolysis to promote oncogenic behavior. Apart from mediating the energy metabolism and controversial effects on ATP production, STAT3 signaling modulates lipid metabolism of cancer cells. By mediating fatty acid synthesis and beta oxidation, STAT3 promotes employment of available resources and supports survival in the conditions of metabolic stress. Thus, the functions of STAT3 extend beyond regulation of oncogenic genes expression to pleiotropic effects on a spectrum of essential cellular processes. In this review, we dissect the current knowledge on activity and mechanisms of STAT3 involvement in transcriptional regulation, mitochondrial function, energy production and lipid metabolism of malignant cells, and its implications to cancer pathogenesis and therapy.

[Research progress in protein post-translational modification in head and neck squamous cell carcinoma].

Head and neck squamous cell carcinoma (HNSCC) is one of the most common malignant tumors, which is prone to tumor recurrence and metastasis. At present, surgery combined with radiotherapy and chemotherapy is the conventional modality for HNSCC patients, but for patients who have tumor relapse or metastasis, the treatment outcome is not ideal and the prognosis is pretty poor. Thus, to deepen the understanding of tumor mechanism will be very crucial. Post-translational modification (PTM) refer to covalent binding of small chemical molecular groups on the amino acid side chain of proteins, which is an important way of protein function regulation as well as a research hotspot of epigenetics. In recent years, it has been found that the occurrence of tumor is often accompanied by the abnormality of PTM. The abnormality plays an important role in the development of tumor and can be used as a target of tumor diagnosis and treatment. Many types of protein PTM involve in the development of HNSCC. This paper reviews the relationship between HNSCC and several major protein PTM types, including acetylation, methylation, glycosylation, in order to provide clues for the clinicians in diagnosis and treatment of HNSCC.

Longitudinal Changes in Protein Carbamylation and Mortality Risk after Initiation of Hemodialysis.

BACKGROUND AND OBJECTIVES: Carbamylation describes a post-translational protein modification associated with adverse outcomes in ESRD, but the risk implications of changes in carbamylation over time are not well understood. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We investigated the 1-year natural history of protein carbamylation in patients initiating maintenance hemodialysis and determined the prognostic value of longitudinal carbamylation changes in relation to mortality. In a nested patient-control study, we measured serial carbamylated albumin concentrations in select participants from a large incident dialysis cohort followed from 2004 to 2005 (n=10,044); 122 individuals who survived at least 90 days but died within 1 year of initiating hemodialysis (patients) were randomly selected along with 244 individuals who survived for at least 1 year (controls; matched for demographics). Carbamylated albumin concentration was measured using plasma collected at dialysis initiation and every subsequent 90-day period until 1 year or death. RESULTS: Baseline carbamylated albumin concentration was similar between controls and patients (mean±SD; 18.9±0.7 and 19.8±1.1 mmol/mol, respectively; P=0.94). From dialysis initiation to day 90, carbamylated albumin concentration markedly fell in all patients, with controls -9.9±0.8 mmol/mol (P<0.001) and patients -10.0±1.2 mmol/mol (P<0.001). Adjusted repeated measures analysis of carbamylated albumin concentration from dialysis initiation to 1 year or death showed that the mean change (95% confidence interval) in carbamylated albumin concentration from baseline to final measure differed significantly between groups (-9.3; 95% confidence interval, -10.8 to -7.7 for controls and -6.3; 95% confidence interval, -7.7 to -2.8 for patients; P<0.01). There were no such between-group differences in blood urea levels, Kt/V, or normalized protein catabolic rate. Mortality prediction assessed using c statistics showed that carbamylated albumin concentration, when modeled continuously as the difference from baseline to final, improved a fully adjusted model from 0.76 to 0.87 (P=0.03). CONCLUSIONS: Protein carbamylation decreased with dialysis initiation, and a greater reduction over time was associated with a lower risk for mortality. Carbamylation changes were able to predict individuals' mortality risk beyond traditional variables, including markers of dialysis adequacy and nutrition.

Dynamic Regulation of APE1/Ref-1 as a Therapeutic Target Protein.

Apurinic/apyrimidinic endonuclease 1/redox factor-1 (APE1/Ref-1) is a multifunctional protein that plays a central role in the cellular response to DNA damage and redox regulation against oxidative stress. APE1/Ref-1 functions in the DNA base excision repair pathway, the redox regulation of several transcription factors, and the control of intracellular redox status through the inhibition of reactive oxygen species (ROS) production. APE1/Ref-1 is predominantly localized in the nucleus; however, its subcellular localization is dynamically regulated and it may be found in the mitochondria or elsewhere in the cytoplasm. Studies have identified a nuclear localization signal and a mitochondrial target sequence in APE1/Ref-1, as well as the involvement of the nuclear export system, as determinants of APE1/Ref-1 subcellular distribution. Recently, it was shown that APE1/Ref-1 is secreted in response to hyperacetylation at specific lysine residues. Additionally, post-translational modifications such as phosphorylation, S-nitrosation, and ubiquitination appear to play a role in fine-tuning the activities and subcellular localization of APE1/Ref-1. In this review, we will introduce the multifunctional role of APE1/Ref-1 and its potential usefulness as a therapeutic target in cancer and cardiovascular disease.

Rescue of Heart Failure by Mitochondrial Recovery.

Heart failure (HF) is a multifactorial disease brought about by numerous, and oftentimes complex, etiological mechanisms. Although well studied, HF continues to affect millions of people worldwide and current treatments can only prevent further progression of HF. Mitochondria undoubtedly play an important role in the progression of HF, and numerous studies have highlighted mitochondrial components that contribute to HF. This review presents an overview of the role of mitochondrial biogenesis, mitochondrial oxidative stress, and mitochondrial permeability transition pore in HF, discusses ongoing studies that attempt to address the disease through mitochondrial targeting, and provides an insight on how these studies can affect future research on HF treatment.

Dynamic Regulation of APE1/Ref-1 as a Therapeutic Target Protein / 전남의대학술지

Apurinic/apyrimidinic endonuclease 1/redox factor-1 (APE1/Ref-1) is a multifunctional protein that plays a central role in the cellular response to DNA damage and redox regulation against oxidative stress. APE1/Ref-1 functions in the DNA base excision repair pathway, the redox regulation of several transcription factors, and the control of intracellular redox status through the inhibition of reactive oxygen species (ROS) production. APE1/Ref-1 is predominantly localized in the nucleus; however, its subcellular localization is dynamically regulated and it may be found in the mitochondria or elsewhere in the cytoplasm. Studies have identified a nuclear localization signal and a mitochondrial target sequence in APE1/Ref-1, as well as the involvement of the nuclear export system, as determinants of APE1/Ref-1 subcellular distribution. Recently, it was shown that APE1/Ref-1 is secreted in response to hyperacetylation at specific lysine residues. Additionally, post-translational modifications such as phosphorylation, S-nitrosation, and ubiquitination appear to play a role in fine-tuning the activities and subcellular localization of APE1/Ref-1. In this review, we will introduce the multifunctional role of APE1/Ref-1 and its potential usefulness as a therapeutic target in cancer and cardiovascular disease.

Rescue of Heart Failure by Mitochondrial Recovery / 대한배뇨장애요실금학회지

Heart failure (HF) is a multifactorial disease brought about by numerous, and oftentimes complex, etiological mechanisms. Although well studied, HF continues to affect millions of people worldwide and current treatments can only prevent further progression of HF. Mitochondria undoubtedly play an important role in the progression of HF, and numerous studies have highlighted mitochondrial components that contribute to HF. This review presents an overview of the role of mitochondrial biogenesis, mitochondrial oxidative stress, and mitochondrial permeability transition pore in HF, discusses ongoing studies that attempt to address the disease through mitochondrial targeting, and provides an insight on how these studies can affect future research on HF treatment.

Dynamic Regulation of APE1/Ref-1 as a Therapeutic Target Protein / 전남의대학술지

Apurinic/apyrimidinic endonuclease 1/redox factor-1 (APE1/Ref-1) is a multifunctional protein that plays a central role in the cellular response to DNA damage and redox regulation against oxidative stress. APE1/Ref-1 functions in the DNA base excision repair pathway, the redox regulation of several transcription factors, and the control of intracellular redox status through the inhibition of reactive oxygen species (ROS) production. APE1/Ref-1 is predominantly localized in the nucleus; however, its subcellular localization is dynamically regulated and it may be found in the mitochondria or elsewhere in the cytoplasm. Studies have identified a nuclear localization signal and a mitochondrial target sequence in APE1/Ref-1, as well as the involvement of the nuclear export system, as determinants of APE1/Ref-1 subcellular distribution. Recently, it was shown that APE1/Ref-1 is secreted in response to hyperacetylation at specific lysine residues. Additionally, post-translational modifications such as phosphorylation, S-nitrosation, and ubiquitination appear to play a role in fine-tuning the activities and subcellular localization of APE1/Ref-1. In this review, we will introduce the multifunctional role of APE1/Ref-1 and its potential usefulness as a therapeutic target in cancer and cardiovascular disease.

Oxidative post-translational modifications develop LONP1 dysfunction in pressure overload heart failure.

BACKGROUND: Mitochondrial compromise is a fundamental contributor to heart failure. Recent studies have revealed that several surveillance systems maintain mitochondrial integrity. The present study evaluated the role of mitochondrial AAA+ protease in a mouse model of pressure overload heart failure. METHODS AND RESULTS: The fluorescein isothiocyanate casein assay and immunoblotting for endogenous mitochondrial proteins revealed a marked reduction in ATP-dependent proteolytic activity in failing heart mitochondria. The level of reduced cysteine was decreased, and tyrosine nitration and protein carbonylation were promoted in Lon protease homolog (LONP1), the most abundant mitochondrial AAA+ protease, in heart failure. Comprehensive analysis revealed that electron transport chain protein levels were increased even with a reduction in the expression of their corresponding mRNAs in heart failure, which indicated decreased protein turnover and resulted in the accumulation of oxidative damage in the electron transport chain. The induction of mitochondria-targeted human catalase ameliorated proteolytic activity and protein homeostasis in the electron transport chain, leading to improvements in mitochondrial energetics and cardiac contractility even during the late stage of pressure overload. Moreover, the infusion of mitoTEMPO, a mitochondria-targeted superoxide dismutase mimetic, recovered oxidative modifications of LONP1 and improved mitochondrial respiration capacity and cardiac function. The in vivo small interfering RNA repression of LONP1 partially canceled the protective effects of mitochondria-targeted human catalase induction and mitoTEMPO infusion. CONCLUSIONS: Oxidative post-translational modifications attenuate mitochondrial AAA+ protease activity, which is involved in impaired electron transport chain protein homeostasis, mitochondrial respiration deficiency, and left ventricular contractile dysfunction. Oxidatively inactivated proteases may be an endogenous target for mitoTEMPO treatment in pressure overload heart failure.

Regulation of acetylation of histone deacetylase 2 by p300/CBP-associated factor/histone deacetylase 5 in the development of cardiac hypertrophy.

RATIONALE: Histone deacetylases (HDACs) are closely involved in cardiac reprogramming. Although the functional roles of class I and class IIa HDACs are well established, the significance of interclass crosstalk in the development of cardiac hypertrophy remains unclear. OBJECTIVE: Recently, we suggested that casein kinase 2α1-dependent phosphorylation of HDAC2 leads to enzymatic activation, which in turn induces cardiac hypertrophy. Here we report an alternative post-translational activation mechanism of HDAC2 that involves acetylation of HDAC2 mediated by p300/CBP-associated factor/HDAC5. METHODS AND RESULTS: Hdac2 was acetylated in response to hypertrophic stresses in both cardiomyocytes and a mouse model. Acetylation was reduced by a histone acetyltransferase inhibitor but was increased by a nonspecific HDAC inhibitor. The enzymatic activity of Hdac2 was positively correlated with its acetylation status. p300/CBP-associated factor bound to Hdac2 and induced acetylation. The HDAC2 K75 residue was responsible for hypertrophic stress-induced acetylation. The acetylation-resistant Hdac2 K75R showed a significant decrease in phosphorylation on S394, which led to the loss of intrinsic activity. Hdac5, one of class IIa HDACs, directly deacetylated Hdac2. Acetylation of Hdac2 was increased in Hdac5-null mice. When an acetylation-mimicking mutant of Hdac2 was infected into cardiomyocytes, the antihypertrophic effect of either nuclear tethering of Hdac5 with leptomycin B or Hdac5 overexpression was reduced. CONCLUSIONS: Taken together, our results suggest a novel mechanism by which the balance of HDAC2 acetylation is regulated by p300/CBP-associated factor and HDAC5 in the development of cardiac hypertrophy.

Tissue transglutaminase contributes to the pathogenesis of preeclampsia and stabilizes placental angiotensin receptor type 1 by ubiquitination-preventing isopeptide modification.

Preeclampsia is a life-threatening pregnancy disorder that is widely thought to be triggered by impaired placental development. However, the placenta-related pathogenic factors are not fully identified, and their underlying mechanisms in disease development remain unclear. Here, we report that the protein level and enzyme activity of tissue transglutaminase (TG2 or tTG), the most ubiquitous member of a family of enzymes that conducts post-translational modification of proteins by forming ε-(γ-glutamyl)-lysine isopeptide bonds, are significantly elevated in placentas of preeclamptic women. TG2 is localized in the placental syncytiotrophoblasts of patients with preeclampsia where it catalyzes the isopeptide modification of the angiotensin receptor type 1 (AT1). To determine the role of elevated TG2 in preeclampsia, we used a mouse model of preeclampsia based on injection of AT1-agonistic autoantibody. A pathogenic role for TG2 in preeclampsia is suggested by in vivo experiments in which cystamine, a potent transglutaminase inhibitor, or small interfering RNA-mediated TG2 knockdown significantly attenuated autoantibody-induced hypertension and proteinuria in pregnant mice. Cystamine treatment also prevented isopeptide modification of placental AT1 receptors in preeclamptic mice. Mechanistically, we revealed that AT1-agonistic autoantibody stimulation enhances the interaction between AT1 receptor and TG2 and results in increased AT1 receptor stabilization via transglutaminase-mediated isopeptide modification in trophoblasts. Mutagenesis studies further demonstrated that TG2-mediated isopeptide modification of AT1 receptors prevents ubiquitination-dependent receptor degradation. Taken together, our studies not only identify a novel pathogenic involvement of TG2 in preeclampsia but also suggest a previously unrecognized role of TG2 in the regulation of G protein-coupled receptor stabilization by inhibiting ubiquitination-dependent degradation.

Targeting the Peroxisome Proliferator-Activated Receptor-γ to Counter the Inflammatory Milieu in Obesity.

Adipose tissue, which was once viewed as a simple organ for storage of triglycerides, is now considered an important endocrine organ. Abnormal adipose tissue mass is associated with defects in endocrine and metabolic functions which are the underlying causes of the metabolic syndrome. Many adipokines, hormones secreted by adipose tissue, regulate cells from the immune system. Interestingly, most of these adipokines are proinflammatory mediators, which increase dramatically in the obese state and are believed to be involved in the pathogenesis of insulin resistance. Drugs that target peroxisome proliferator-activated receptor-γ have been shown to possess anti-inflammatory effects in animal models of diabetes. These findings, and the link between inflammation and the metabolic syndrome, will be reviewed here.

Targeting the Peroxisome Proliferator-Activated Receptor-gamma to Counter the Inflammatory Milieu in Obesity

Adipose tissue, which was once viewed as a simple organ for storage of triglycerides, is now considered an important endocrine organ. Abnormal adipose tissue mass is associated with defects in endocrine and metabolic functions which are the underlying causes of the metabolic syndrome. Many adipokines, hormones secreted by adipose tissue, regulate cells from the immune system. Interestingly, most of these adipokines are proinflammatory mediators, which increase dramatically in the obese state and are believed to be involved in the pathogenesis of insulin resistance. Drugs that target peroxisome proliferator-activated receptor-gamma have been shown to possess anti-inflammatory effects in animal models of diabetes. These findings, and the link between inflammation and the metabolic syndrome, will be reviewed here.

Stathmin: a potential tumor biomarker / 肿瘤

Stathmin, a ubiquitously expressed cytosolic protein(Mr=19×10~3), is also called oncogene protein 18 (Op18). Stathmin is involved in the assembly of microtubule (MT) and spindle by binding the tubulin protein. It plays a key role in cell proliferation, differentiation, regeneration, and migration and has regulatory effects on the signal transduction. Recently, it is reported that stathmin is overexpressed in a variety of human malignancies. It induces tumor cell migration and invasion by regulating MT depolymeri-zation. Its post-translational modification influences the interaction with p53 protein and is involved in the initiation and progression of malignant tumor. Stathmin alone or in combination with chemotherapeutics has been used for tumor therapy. The internal association of stathmin with cancer etiology is still unknown. So, further studies are needed to determine the role of stathmin as potential tumor biomarker and a drug target in tumor therapy.

The role of O-GlcNAc modification in glutamine-induced myocardial heat shock protein 70 expression in a rat model of endotoxic shock / 中华麻醉学杂志

Objective To investigate the role of O-linked N-acetylglutamine (O-GlcNAc) modification in glutamine-induced myocardial heat shock protein (HSP70) expression in a rat model of endotoxic shock. Methods Thirty-two 8 weeks old male SD rats weighing 250-300 g were randomly divided into 4 groups (n = 8 each):group Ⅰ control (group C); group Ⅱ LPS; group Ⅲ G+ LPS and group glutamine + LPS (group A + G + LPS). Endotoxic shock was induced by iv administration of LPS 10 mg/kg in group Ⅱ , Ⅲ and Ⅳ.Glutamine 0.75 g/kg was administered iv at 1 h before iv LPS in group Ⅲ and Ⅳ . Alloxan (an inhibitor ofO-linked N-acetylglucosamine transferase) 50 mg/kg was administered iv together with glutamine at 1 h before LPS in group Ⅳ. The animals were sacrificed at 6 h after iv LPS administration. Their hearts were removed for determination of the expression of O-GlcNAc and HSP70 in myocardium. Results Intravenous LPS significantly up-regulated the expression of O-GlcNAc and HSP70. Glutamine pretreatment further increased the expression of O-GlcNAc and HSP70. The glutamine pretreatment induced increase in O-GlcNAc and HSP70 expression was abolished by concomitant administration of alloxan. Conclusion O-GlcNAc modification may be involved in glutamine-induced myocardial HSP70 expression in endotoxic shock.

Effects of O-GIcNAc modification on glutamine-induced heat shock protein 70 expression in LPS-treated rat cardiomyocytes / 中华麻醉学杂志

Objective To investigate the effects of O-GlcNAc modification on gintamine (Glu)-induced heat shock protein 70 (HSP70) expression in LPS-treated rat cardiomyocytes.Methods Primary cultures of neonatal rat cardiomyocytes were randomly divided into 6 groups:group Ⅰ control(group C);group Ⅱ Glu;group Ⅲ LPS;group Ⅳ Glu+LPS;group Ⅴ Glu+LPS+Alloxan and group Ⅵ Gln+LPS+PUGNAc.In group C double distilled water 25 μl was added.In group Ⅱ-Ⅵ the cells were exposed to the sanle concentrations of Glu (5 mmol/L)and LPS(4 μg/ml) except Alloxan (an inhibiter of O-linked β-N-acetyl glucosamine transferase/OGT) (1 mmol/L) and PUGNAc (an inhibitor of O-linked β-N-acetyl glucosaminidase/OGA)(100μmol/L).After being incubated for 6 h,cardiomyocyte viability,O-GlcNAc modification level and HSP70 expression level were measured.Results There was no significant difference in cell viability among the six groups.The levels of O-GlcNAc modification and HSP70 expression were significantly higher in group Ⅱ-Ⅵ than in group Ⅰ,were significantly higher in group Ⅳ and group Ⅵ than in group Ⅲ,were significantly lower in group Ⅴ and higher in group Ⅵ than in group Ⅳ.Conclusion O-GlcNAc modification may be involved in Glu-induced HSPT0 expression in LPS-treated cardiomyocytes.

Cytokeratin 8 and cancer / 国际肿瘤学杂志

Cytokeratin 8 ( CK8 ) belongs to the keratin family of intermediate filament cytoskeletal proteins. A lot of researches have demonstrated that abnormal expression or post-translational modifications of CK8 may affect its activity and consequently affect the development and progression of tumors. Therefore, investigating the role of CK8 in tumorigenesis may contribute to the prevention and treatment of tumors.

Overexpression of nicotinamide N-methyltransferase in gastric cancer tissues and its potential post-translational modification

Gastric cancer is one of the most common cancers worldwide. The purpose of this study was to find out potential markers for gastric cancer. Tumor and normal tissues from 152 gastric cancer cases were analyzed by two-dimensional gel electrophoresis (2-DE). The images of silver stained gels were analyzed and statistical analysis of spot intensities revealed that spot 4262 showed higher expression (5.7-fold increase) in cancer tissues than in normal tissues (P< 0.001). It was identified by peptide mass fingerprinting as nicotinamide N-methyltransferase (NNMT). A monoclonal antibody with a detection limit down to 10 ng was produced against NNMT in mouse. Using the prepared monoclonal antibody, western blot analysis of NNMT was performed for gastric tissues from 15 gastric cancer patients and two gastric ulcer patients. The results corroborated those of 2-DE experiments. A single spot was detected in gastric ulcer tissues while four to five spots were detected in gastric cancer tissues. In cancer tissues, two additional spots of acidic and basic form were mainly detected on 2-DE gels. This suggests that NNMT receives a post-translational modification in cancer- specific manner.