LNX1 contributes to tumor growth by down-regulating p53 stability.

The well-known tumor suppressor p53 inhibits the formation of various cancers by inducing cell cycle arrest and apoptosis. Although p53 mutations are commonly found in many cancers, p53 is functionally inactivated in tumor cells that retain wild-type p53. Here, we show that the ligand of numb protein X1 (LNX1) inhibited p53-dependent transcription by decreasing the half-life of p53. We generated LNX1 knockout (KO) cells in p53 wild-type cancer cells (A549, HCT116, and MCF7) using the clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 gene-editing system. LNX1 KO activated p53-dependent transcription by increasing the stability of p53. Moreover, lentivirus-mediated overexpression of LNX1 decreased p53 protein levels and inhibited p53-dependent transcription. LNX1 interacted with p53 and mouse double minute 2 (MDM2) and increased the ubiquitination of p53 in an MDM2-dependent manner. Finally, we demonstrated that LNX1 was required for efficient tumor growth both in cell culture and in a mouse tumor xenograft model. These results collectively indicated that LNX1 contributed to tumor growth by inhibiting p53-dependent signaling in p53 wild-type cancer cells.-Park, R., Kim, H., Jang, M., Jo, D., Park, Y.-I., Namkoong, S., Lee, J. I., Jang, I.-S., Park, J. LNX1 contributes to tumor growth by down-regulating p53 stability.

Meridianin C inhibits the growth of YD-10B human tongue cancer cells through macropinocytosis and the down-regulation of Dickkopf-related protein-3.

Meridianin C is a marine natural product known for its anti-cancer activity. At present, the anti-tumour effects of meridianin C on oral squamous cell carcinoma are unknown. Here, we investigated the effect of meridianin C on the proliferation of four different human tongue cancer cells, YD-8, YD-10B, YD-38 and HSC-3. Among the cells tested, meridianin C most strongly reduced the growth of YD-10B cells; the most aggressive and tumorigenic of the cell lines tested. Strikingly, meridianin C induced a significant accumulation of macropinosomes in the YD-10B cells; confirmed by the microscopic and TEM analysis as well as the entry of FITC-dextran, which was sensitive to the macropinocytosis inhibitor amiloride. SEM data also revealed abundant long and thin membrane extensions that resemble lamellipodia on the surface of YD-10B cells treated with meridianin C, pointing out that meridianin C-induced macropinosomes was the result of macropinocytosis. In addition, meridianin C reduced cellular levels of Dickkopf-related protein-3 (DKK-3), a known negative regulator of macropinocytosis. A role for DKK-3 in regulating macropinocytosis in the YD-10B cells was confirmed by siRNA knockdown of endogenous DKK-3, which led to a partial accumulation of vacuoles and a reduction in cell proliferation, and by exogenous DKK-3 overexpression, which resulted in a considerable inhibition of the meridianin C-induced vacuole formation and decrease in cell survival. In summary, this is the first study reporting meridianin C has novel anti-proliferative effects via macropinocytosis in the highly tumorigenic YD-10B cell line and the effects are mediated in part through down-regulation of DKK-3.

Monitoring of post-mortem changes of saliva N-glycosylation by nano LC/MS.

The estimation of post-mortem interval (PMI) is a crucial part for investigations of crime and untimely deaths in forensic science. However, standard methods of PMI estimation are easily confounded by extenuating circumstances and/or environmental factors. Therefore, a panel of PMI markers obtained from a more acceptable and accurate method is necessary to definitely determine time of death. Saliva, one of the vital fluids encountered at crime scenes, contains various glycoproteins that are highly affected by biochemical environment. Here, we investigated saliva N-glycans between live and dead rats to determine the alteration of N-glycans using an animal model system because of the limitation of saliva collection from recently deceased humans. Rat saliva samples were collected both before and after death. N-Glycans were enzymatically released by PNGase F without any glycoprotein extraction. Released native glycans were purified and enriched by PGC-SPE. About 100 N-glycans were identified, profiled, and structurally elucidated by nano LC/MS and tandem MS. Sialylated N-glycans were exclusively present in abundance in live rat saliva whereas non-sialylated N-glycans including LacdiNAc disaccharides were detected in high level following death. Through in-depth investigations using quantitative comparison and statistical analysis, 14 N-glycans that significantly changed after death were identified as the potential marker candidates for PMI estimation. To the best of our knowledge, this is the first study to monitor the post-mortem changes of saliva glycosylation, with obvious forensic applications.

Medium chain unsaturated fatty acid ethyl esters inhibit persister formation of Escherichia coli via antitoxin HipB.

Persisters represent a small bacterial population that is dormant and that survives under antibiotic treatment without experiencing genetic adaptation. Persisters are also considered one of the major reasons for recalcitrant chronic bacterial infections. Although several mechanisms of persister formation have been proposed, it is not clear how cells enter the dormant state in the presence of antibiotics or how persister cell formation can be effectively controlled. A fatty acid compound, cis-2-decenoic acid, was reported to decrease persister formation as well as revert the dormant cells to a metabolically active state. We reasoned that some fatty acid compounds may be effective in controlling bacterial persistence because they are known to benefit host immune systems. This study investigated persister cell formation by pathogens that were exposed to nine fatty acid compounds during antibiotic treatment. We found that three medium chain unsaturated fatty acid ethyl esters (ethyl trans-2-decenoate, ethyl trans-2-octenoate, and ethyl cis-4-decenoate) decreased the level of Escherichia coli persister formation up to 110-fold when cells were exposed to ciprofloxacin or ampicillin antibiotics. RNA sequencing analysis and gene deletion persister studies elucidated that these fatty acids inhibit bacterial persistence by regulating antitoxin HipB. A similar persister cell reduction was observed for pathogenic E. coli EDL933, Pseudomonas aeruginosa PAO1, and Serratia marcescens ICU2-4 strains. This study demonstrates that fatty acid ethyl esters can be used to disrupt bacterial dormancy to combat persistent infectious diseases.

Protein Tyrosine Phosphatases as Potential Regulators of STAT3 Signaling.

The signal transducer and activator of transcription 3 (STAT3) protein is a major transcription factor involved in many cellular processes, such as cell growth and proliferation, differentiation, migration, and cell death or cell apoptosis. It is activated in response to a variety of extracellular stimuli including cytokines and growth factors. The aberrant activation of STAT3 contributes to several human diseases, particularly cancer. Consequently, STAT3-mediated signaling continues to be extensively studied in order to identify potential targets for the development of new and more effective clinical therapeutics. STAT3 activation can be regulated, either positively or negatively, by different posttranslational mechanisms including serine or tyrosine phosphorylation/dephosphorylation, acetylation, or demethylation. One of the major mechanisms that negatively regulates STAT3 activation is dephosphorylation of the tyrosine residue essential for its activation by protein tyrosine phosphatases (PTPs). There are seven PTPs that have been shown to dephosphorylate STAT3 and, thereby, regulate STAT3 signaling: PTP receptor-type D (PTPRD), PTP receptor-type T (PTPRT), PTP receptor-type K (PTPRK), Src homology region 2 (SH-2) domain-containing phosphatase 1(SHP1), SH-2 domain-containing phosphatase 2 (SHP2), MEG2/PTP non-receptor type 9 (PTPN9), and T-cell PTP (TC-PTP)/PTP non-receptor type 2 (PTPN2). These regulators have great potential as targets for the development of more effective therapies against human disease, including cancer.

Tetraspanin-2 promotes glucotoxic apoptosis by regulating the JNK/ß-catenin signaling pathway in human pancreatic ß cells.

Diabetes mellitus is a complex and heterogeneous disease, which has ß-cell dysfunction at its core. Glucotoxicity affects pancreatic islets, causing ß-cell apoptosis. However, the role of JNK/ß-catenin signaling in glucotoxic ß-cell apoptosis is not well understood. Recently, we identified tetraspanin-2 (TSPAN2) protein as a proapoptotic ß-cell factor induced by glucose, suggesting that TSPAN2 might contribute to pancreatic ß-cell glucotoxicity. To investigate the effects of glucose concentration on TSPAN2 expression and apoptosis, we used reverted immortalized RNAKT-15 human pancreatic ß cells. High TSPAN2 levels up-regulated phosphorylated (p) JNK and induced apoptosis. p-JNK enhanced the phosphorylation of ß-catenin and Dickkopf-1 (Dkk1). Dkk1 knockdown by small interfering (si)RNA up-regulated nuclear ß-catenin, suggesting that it is a JNK/ß-catenin-dependent pathway. siRNA-mediated TSPAN2 depletion in RNAKT-15 cells increased nuclear ß-catenin. This decreased BCL2-associated X protein (Bax) activation, leading to marked protection against high glucose-induced apoptosis. Bax subfamily proteins induced apoptosis through caspase-3. Thus, TSPAN2 might have induced Bax translocation and caspase-3 activation in pancreatic ß cells, thereby promoting the apoptosis of RNAKT-15 cells by regulating the JNK/ß-catenin pathway in response to high glucose concentrations. Targeting TSPAN2 could be a potential therapeutic strategy to treat glucose toxicity-induced ß-cell failure.-Hwang, I.-H., Park, J., Kim, J. M., Kim, S. I., Choi, J.-S., Lee, K.-B., Yun, S. H., Lee, M.-G., Park, S. J., Jang, I.-S. Tetraspanin-2 promotes glucotoxic apoptosis by regulating the JNK/ß-catenin signaling pathway in human pancreatic ß cells.

Anti-cancer effect of Scutellaria baicalensis in combination with cisplatin in human ovarian cancer cell.

BACKGROUND: Ovarian cancer is one of the major causes of death among females in worldwide. Cisplatin is a primary anti-cancer drug against ovarian cancer, but the recurrent tumors after treatment frequently show acquired chemoresistance. Extract of Scutellaria baicalensis (SbE) has been reported to have functional compounds including baicalin, which has anti-cancer effects. However, the anti-cancer effects of SbE in ovarian cancer and its underlying mechanisms are elusive. METHODS: We investigated that the effects of SbE and/or cisplatin on cell death in the cisplatin sensitive ovarian cancer cell line A2780 (CSC) and the counterpart cell line that has cisplatin resistance (CRC). Molecular mechanisms of the effects, focusing on apoptosis and autophagy, were examined. RESULTS: Treatment of cisplatin or SbE reduced cell viability significantly in CSC and too much lesser extent in CRC. Cisplatin-induced cell death in CSC was mediated by p53-induced apoptosis acompanied by expresson of damage-regulated autophagy modulator (DRAM). In CRC, decreased DRAM expression (p < 0.01) hindered p21-mediated cell death and contributed to cisplatin resistance. Treatment of SbE also induced cell death in CSC by p53-dependent apoptosis, not in CRC. Autophagy was not induced by neither cisplatin nor SbE. Intriguingly, the combinational treatment of SbE and cisplatin significantly decreased cell viability in CRC. The cell death was mediated by autophagy with increased expression of Atg5 and Atg12 (p < 0.05), rather than p53-dependent pathway with repressed expression of p21 (p < 0.001) through HDAC1 activation. CONCLUSIONS: The combined treatment of SbE with cisplatin was effective in CRC, leading to cell death via Beclin1-independent autophagy, suggesting that SbE treatment in combination with cisplatin has a potential as a chemotherapeutic agent in cisplatin-resistant ovarian cancer.

Inhibition of CYP4A reduces hepatic endoplasmic reticulum stress and features of diabetes in mice.

BACKGROUND & AIMS: Endoplasmic reticulum (ER) stress is implicated in the development of type 2 diabetes mellitus. ER stress activates the unfolded protein response pathway, which contributes to apoptosis and insulin resistance. We investigated the roles of cytochrome P450 4A (CYP4A) in the regulation of hepatic ER stress, insulin resistance, and the development of diabetes in mice. METHODS: We used mass spectrometry to compare levels of CYP450 proteins in livers from C57BL/6J and C57BL/KsJ-db/db (db/db) mice; findings were confirmed by immunoblot and real-time PCR analyses. To create a model of diet-induced diabetes, C57BL/6J mice were placed on high-fat diets. Mice were given intraperitoneal injections of an inhibitor (HET0016) or an inducer (clofibrate) of CYP4A, or tail injections of small hairpin RNAs against CYP4A messenger RNA; liver tissues were collected and analyzed for ER stress, insulin resistance, and apoptosis. The effect of HET0016 and CYP4A knockdown also were analyzed in HepG2 cells. RESULTS: Levels of the CYP4A isoforms were highly up-regulated in livers of db/db mice compared with C57BL/6J mice. Inhibition of CYP4A in db/db and mice on high-fat diets reduced features of diabetes such as insulin hypersecretion, hepatic steatosis, and increased glucose tolerance. CYP4A inhibition reduced levels of ER stress, insulin resistance, and apoptosis in the livers of diabetic mice; it also restored hepatic functions. Inversely, induction of CYP4A accelerated ER stress, insulin resistance, and apoptosis in livers of db/db mice. CONCLUSIONS: CYP4A proteins are up-regulated in livers of mice with genetically induced and diet-induced diabetes. Inhibition of CYP4A in mice reduces hepatic ER stress, apoptosis, insulin resistance, and steatosis. Strategies to reduce levels or activity of CYP4A proteins in liver might be developed for treatment of patients with type 2 diabetes.

Spatially-resolved exploration of the mouse brain glycome by tissue glyco-capture (TGC) and nano-LC/MS.

Tissue glyco-capture (TGC), a highly sensitive MS-compatible method for extraction of glycans from tissue, was combined with structure-specific nano-LC/MS for sensitive and detailed profiling of the mouse brain glycome. Hundreds of glycan structures were directly detected by accurate mass MS and structurally elucidated by MS/MS, revealing the presence of novel glycan motifs such as antennary fucosylation, sulfation, and glucuronidation that are potentially associated with cellular signaling and adhesion. Microgram-level sensitivity enabled glycomic analysis of specific regions of the brain, as demonstrated on not only brain sections (with a one-dimensional spatial resolution of 20 µm) but also isolated brain structures (e.g., the hippocampus). Reproducibility was extraordinarily high (R > 0.98) for both method and instrumental replicates. The pairing of TGC with structure-specific nano-LC/MS was found to be an exceptionally powerful platform for qualitative and quantitative exploration of the brain glycome.

Ginsenoside Rg3 up-regulates the expression of vascular endothelial growth factor in human dermal papilla cells and mouse hair follicles.

Crude Panax ginseng has been documented to possess hair growth activity and is widely used to treat alopecia, but the effects of ginsenoside Rg3 on hair growth have not to our knowledge been determined. The aim of the current study was to identify the molecules through which Rg3 stimulates hair growth. The thymidine incorporation for measuring cell proliferation was determined. We used DNA microarray analysis to measure gene expression levels in dermal papilla (DP) cells upon treatment with Rg3. The mRNA and protein expression levels of vascular endothelial growth factor (VEGF) in human DP cells were measured by real-time polymerase chain reaction and immunohistochemistry, respectively. We also used immunohistochemistry assays to detect in vivo changes in VEGF and 3-stemness marker expressions in mouse hair follicles. Reverse transcription polymerase chain reaction showed dose-dependent increases in VEGF mRNA levels on treatment with Rg3. Immunohistochemical analysis showed that expression of VEGF was significantly up-regulated by Rg3 in a dose-dependent manner in human DP cells and in mouse hair follicles. In addition, the CD8 and CD34 were also up-regulated by Rg3 in the mouse hair follicles. It may be concluded that Rg3 might increase hair growth through stimulation of hair follicle stem cells and it has the potential to be used in hair growth products.

Proteomic and bioinformatic analysis of membrane proteome in type 2 diabetic mouse liver.

Type 2 diabetes mellitus (T2DM) is the most prevalent and serious metabolic disease affecting people worldwide. T2DM results from insulin resistance of the liver, muscle, and adipose tissue. In this study, we used proteomic and bioinformatic methodologies to identify novel hepatic membrane proteins that are related to the development of hepatic insulin resistance, steatosis, and T2DM. Using FT-ICR MS, we identified 95 significantly differentially expressed proteins in the membrane fraction of normal and T2DM db/db mouse liver. These proteins are primarily involved in energy metabolism pathways, molecular transport, and cellular signaling, and many of them have not previously been reported in diabetic studies. Bioinformatic analysis revealed that 16 proteins may be related to the regulation of insulin signaling in the liver. In addition, six proteins are associated with energy stress-induced, nine proteins with inflammatory stress-induced, and 14 proteins with endoplasmic reticulum stress-induced hepatic insulin resistance. Moreover, we identified 19 proteins that may regulate hepatic insulin resistance in a c-Jun amino-terminal kinase-dependent manner. In addition, three proteins, 14-3-3 protein beta (YWHAB), Slc2a4 (GLUT4), and Dlg4 (PSD-95), are discovered by comprehensive bioinformatic analysis, which have correlations with several proteins identified by proteomics approach. The newly identified proteins in T2DM should provide additional insight into the development and pathophysiology of hepatic steatosis and insulin resistance, and they may serve as useful diagnostic markers and/or therapeutic targets for these diseases.

Amurensin G induces autophagy and attenuates cellular toxicities in a rotenone model of Parkinson's disease.

Although Parkinson's disease is a common neurodegenerative disorder its cause is still unknown. Recently, several reports showed that inducers of autophagy attenuate cellular toxicities in Parkinson's disease models. In this report we screened HEK293 cells that stably express GFP-LC3, a marker of autophagy, for autophagy inducers and identified amurensin G, a compound isolated from the wild grape (Vitis amurensis). Amurensin G treatment induced punctate cytoplasmic expression of GFP-LC3 and increased the expression level of endogenous LC3-II. Incubation of human dopaminergic SH-SY5Y cells with amurensin G attenuated the cellular toxicities of rotenone in a model of Parkinson's disease. Amurensin G inhibited rotenone-induced apoptosis and interfered with rotenone-induced G2/M cell cycle arrest. In addition, knockdown of beclin1, a regulator of autophagy, abolished the effect of amurensin G. These data collectively indicate that amurensin G attenuates cellular toxicities through the induction of autophagy.

Whitening effect of Sophora flavescens extract.

CONTEXT: Sophora flavescens Ait. (Leguminosae) has been proposed as a new whitening agent for cosmetics, because it has a strong ability to inhibit tyrosinase, a key enzyme in the formation of melanin. OBJECTIVE: We conducted a study to determine whether ethanol extract of the roots of S. flavescens has the potential for use as a whitening cosmetic agent by investigating its underlying mechanisms of action. MATERIALS AND METHODS: To elucidate the mechanism of action of S. flavescens extract, we used DNA microarray technology. We investigated the changes in the mRNA levels of genes associated with the formation and transport of melanosomes. We also identified the formation and transport of melanosomes with immunohistochemistry and immunofluorescence analyses. Finally, the skin-whitening effect in vivo of S. flavescens extract was analyzed on human skin. RESULTS: We found that S. flavescens extract strongly inhibited tyrosinase activity (IC50, 10.4 µg/mL). Results also showed that key proteins involved in the formation and transport of melanosomes were dramatically downregulated at both mRNA and protein level in keratinocytes exposed to S. flavescens extract. In addition, a clinical trial of a cream containing 0.05% S. flavescens extract on human skin showed it had a significant effect on skin whitening by mechanical and visual evaluation (1.14-fold). DISCUSSION AND CONCLUSION: This study provides important clues toward understanding the effects of S. flavescens extract on the formation and transport of melanosomes. From these results, we suggest that naturally occurring S. flavescens extract might be useful as a new whitening agent in cosmetics.

Roles of interferon-gamma and its target genes in schizophrenia: Proteomics-based reverse genetics from mouse to human.

A decreased production of interferon gamma (IFNG) has been observed in acute schizophrenia. In order to explore the possible relationship between IFNG and schizophrenia, we attempted to analyze the differentially expressed proteins in the brains of interferon-gamma knockout (Ifng-KO) mice. Five upregulated and five downregulated proteins were identified with 2D gels and MALDI-TOF/TOF MS analyses in Ifng-KO mouse brain. Of the identified proteins, we focused on creatine kinase brain (CKB) and triose phosphate isomerase 1 (TPI1). Consistent with the proteomic data, reverse transcriptase-mediated PCR, immunoblotting, and immunohistochemistry analyses confirmed that the levels of gene expressions of Ckb and Tpi1 were downregulated and upregulated, respectively. When we analyzed the genetic polymorphisms of the single nucleotide polymorphisms (SNPs) of their human orthologous genes in a Korean population, the promoter SNPs of CKB and TPI1 were weakly associated with schizophrenia. In addition, IFNG polymorphisms were associated with schizophrenia. These results suggest that IFNG and proteins affected by IFNG may play a role in the pathogenesis of schizophrenia.

The expression of damage-regulated autophagy modulator 2 (DRAM2) contributes to autophagy induction.

Autophagy is a membrane trafficking process involved in intracellular degradation and recycling in eukaryotic cells. DRAM2 (damage-regulated autophagy modulator 2) is a homologue of DRAM that regulates p53-mediated cell death. As its name implies, DRAM expression induces autophagy in a p53-dependent manner; however, the role of DRAM2 in autophagy is not clear. In this study, we report that DRAM2 expression contributes to autophagy induction. Overexpression of DRAM2 induces cytoplasmic GFP-LC3 punctuates, and increases the level of endogenous LC3-II. Moreover, the silencing of endogenous DRAM2 interferes with starvation-induced autophagy. Thus, we propose that DRAM2 as well as DRAM are involved in autophagy.

Terpenylated coumarins as SIRT1 activators isolated from Ailanthus altissima.

Four new terpenylated coumarins (1-4) were isolated from the stem bark of Ailanthus altissima by bioactivity-guided fractionation using an in vitro SIRT1 deacetylation assay. Their structures were identified as (2'R,3'R)-7-(2',3'-dihydroxy-3',7'-dimethylocta-6'-enyloxy)-6,8-dimethoxycoumarin (1), 6,8-dimethoxy-7-(3',7'-dimethylocta-2',6'-dienyloxy)coumarin (2), (2'R,3'R,6'R)-7-(2',3'-dihydroxy-6',7'-epoxy-3',7'-dimethyloctaoxy)-6,8-dimethoxycoumarin (3), and (2'R,3'R,4'S,5'S)-6,8-dimethoxy-7-(3',7'-dimethyl-4',5'-epoxy-2'-hydroxyocta-6'-enyloxy)coumarin (4). Compounds 1-4 strongly enhanced SIRT1 activity in an in vitro SIRT1-NAD/NADH assay and an in vivo SIRT1-p53 luciferase assay. These compounds also increased the NAD-to-NADH ratio in HEK293 cells. The present results suggest that terpenylated coumarins from A. altissima have a direct stimulatory effect on SIRT1 deacetylation activity and may serve as lead molecules for the treatment of some age-related disorders.

Modulation of insulin sensitivity and caveolin-1 expression by orchidectomy in a nonobese type 2 diabetes animal model.

Previously, we found that male JYD mice developed type 2 diabetes but female mice did not, and that decreased expression levels of caveolin-1 were correlated with the development of a diabetic phenotype in these mice. Therefore, we hypothesized that sex hormones affect the expression of caveolin-1 and contribute to the development of insulin resistance and hyperglycemia in JYD mice. We used glucose and insulin tolerance tests to examine insulin sensitivity in male, female and orchidectomized male JYD mice. Glucose uptake was analyzed by using (18)F-fluorodeoxyglucose positron emission tomography. We also examined insulin-signaling molecules and caveolin proteins in various tissues in these mice by Western blotting. In addition, we examined changes of caveolin-1 expression in L6 skeletal muscle cells treated with 17-ß estradiol or dihydroxytestosterone. We found that glucose and insulin tolerance were impaired and hyperglycemia developed in male, but not female, JYD mice. Expression of insulin-signaling molecules such as insulin receptor, protein kinase B, and glucose transporter-4 were decreased in male JYD mice compared with female mice. Orchidectomized JYD male mice showed improved glucose and insulin tolerance with a concomitant increase in the expression of insulin-signaling molecules and caveolin-1 in adipose tissue and skeletal muscle. Moreover, 17-ß-estradiol treatment increased the expression of caveolin-1 in differentiated skeletal muscle cells. We conclude that sex hormones modulate the expression of caveolin-1 and insulin-signaling molecules, subsequently affecting insulin sensitivity and the development of type 2 diabetes in JYD mice.

Alpinumisoflavone induces apoptosis and suppresses extracellular signal-regulated kinases/mitogen activated protein kinase and nuclear factor-κB pathways in lung tumor cells.

The extracellular signal-regulated kinases/mitogen activated protein kinase (ERK/MAPK) and nuclear factor-κB (NF-κB) pathways are critical for cell survival and proliferation. Alpinumisoflavone (AIF), isolated from the African medicinal plant Erythrina lysistemon, is a member of the isoflavone group. In this report, we demonstrated that AIF treatment induces cell death of human lung tumor cells. Incubation of lung tumor cells with AIF increased the sub-G1 population and caspase 3/7 activity, suggesting that the cell death is caused by apoptosis. To identify the signaling pathway involved in the tumor cell death, we examined the modulation of transcriptional activity using various reporter constructs and found that AIF significantly deregulated both the ERK/MAPK and NF-κB pathways. Western blot analysis with antibodies to MAP/ERK kinase (MEK) and ERK showed that AIF dephosphorylates both MEK and ERK. Alpinumisoflavone also repressed lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW264.7 cells by inhibiting NF-κB-dependent transcription. Therefore, the cell death induced by AIF may be via repressing both the ERK/MAPK and NF-κB pathways.

Non-synonymous SNP in the ApoR gene associated with pork meat quality.

Two novel non-synonymous SNPs in the 2nd and 3rd exons of the porcine ApoR gene are reported. One was identified as a novel SNP significantly associated with multiple traits of pork meat quality. The data can provide a useful resource for developing a marker in the genetic improvement of pigs.

SUMOylated IRF-1 shows oncogenic potential by mimicking IRF-2.

Interferon regulatory factor-1 (IRF-1) is an interferon-induced transcriptional activator that suppresses tumors by impeding cell proliferation. Recently, we demonstrated that the level of SUMOylated IRF-1 is elevated in tumor cells, and that SUMOylation of IRF-1 attenuates its tumor-suppressive function. Here we report that SUMOylated IRF-1 mimics IRF-2, an antagonistic repressor, and shows oncogenic potential. To demonstrate the role of SUMOylated IRF-1 in tumorigenesis, we used SUMO-IRF-1 recombinant protein. Stable expression of SUMO-IRF-1 in NIH3T3 cells resulted in focus formation and anchorage-independent growth in soft agar. Inoculation of SUMO-IRF-1-transfected cells into athymic nude mice resulted in tumor formation and infiltration of adipose tissues. Finally, we demonstrated that SUMO-IRF-1 transforms NIH3T3 cells in a dose-dependent manner suggesting that SUMOylated IRF-1 may act as an oncogenic protein in tumor cells.