The potential oncogenic effect of tissue-specific expression of JC polyoma T antigen in digestive epithelial cells.

JC polyoma virus (JCPyV), a ubiquitous polyoma virus that commonly infects people, is identified as the etiologic factor for progressive multifocal leukoencephalopathy and has been closely linked to various human cancers. Transgenic mice of CAG-loxp-Laz-loxp T antigen were established. T-antigen expression was specifically activated in gastroenterological target cells with a LacZ deletion using a cre-loxp system. Gastric poorly-differentiated carcinoma was observed in T antigen-activated mice using K19-cre (stem-like cells) and PGC-cre (chief cells), but not Atp4b-cre (parietal cells) or Capn8-cre (pit cells) mice. Spontaneous hepatocellular and colorectal cancers developed in Alb-cre (hepatocytes)/T antigen and villin-cre (intestinal cells)/T antigen transgenic mice respectively. Gastric, colorectal, and breast cancers were observed in PGC-cre/T antigen mice. Pancreatic insulinoma and ductal adenocarcinoma, gastric adenoma, and duodenal cancer were detected in Pdx1-cre/T antigen mice. Alternative splicing of T antigen mRNA occurred in all target organs of these transgenic mice. Our findings suggest that JCPyV T antigen might contribute to gastroenterological carcinogenesis with respect to cell specificity. Such spontaneous tumor models provide good tools for investigating the oncogenic roles of T antigen in cancers of the digestive system.

Everolimus-inhibited multiple isoforms of UDP-glucuronosyltransferases (UGTs).

1. Everolimus is an inhibitor of mammalian target of rapamycin (mTOR) and has been clinically utilized to prevent the rejection of organ transplants. This study aims to determine the inhibition of everolimus on the activity of phase-II drug-metabolizing enzymes UDP-glucuronosyltransferases (UGTs). 2. The results showed that 100 µM of everolimus exerted more than 80% inhibition toward UGT1A1, UGT-1A3 and UGT-2B7. UGT1A3 and UGT2B7 were selected to elucidate the inhibition mechanism, and in silico docking showed that hydrogen bonds and hydrophobic interactions mainly contributed to the strong binding of everolimus toward the activity cavity of UGT1A3 and UGT2B7. Inhibition kinetic-type analysis using Lineweaver-Burk plot showed competitive inhibition toward all these UGT isoforms. The inhibition kinetic parameters (Ki) were calculated to be 2.3, 0.07 and 4.4 µM for the inhibition of everolimus toward UGT1A1, UGT-1A3 and UGT-2B7, respectively. 3. In vitro-in vivo extrapolation (IVIVE) showed that [I]/Ki value was calculated to be 0.004, 0.14 and 0.002 for UGT1A1, UGT-1A3 and UGT-2B7, respectively. Therefore, high DDI potential existed between everolimus and clinical drugs mainly undergoing UGT1A3-catalyzed glucuronidation.

The inhibition of UDP-glucuronosyltransferases (UGTs) by tetraiodothyronine (T4) and triiodothyronine (T3).

1. UDP-glucuronosyltransferases (UGTs) are important drug-metabolizing enzymes (DMEs) catalyzing the glucuronidation elimination of various xenobiotics and endogenous substances. Endogenous substances are important regulators for the activity of various UGT isoforms. Triiodothyronine (T3) and thyroxine (T4) are important thyroid hormones essential for normal cellular differentiation and growth. The present study aims to elucidate the inhibition behavior of T3 and T4 on the activity of UGT isoforms. 2. In vitro recombinant UGTs-catalyzed glucuronidation of 4-methylumbelliferone (4-MU) was used to screen the inhibition potential of T3 and T4 on the activity of various UGT isoforms. Initial screening results showed that T4 exerted stronger inhibition potential than T3 on the activity of various UGT isoforms at 100 µM. Inhibition kinetics was determined for the inhibition of T4 on the representative UGT isoforms, including UGT1A1, -1A3, -1A7, -1A8, -1A10 and -2B7. The results showed that T4 competitively inhibited the activity of UGT1A1, -1A3, -1A7, 1A10 and -2B7, and noncompetitively inhibited the activity of UGT1A8. The inhibition kinetic parameters were calculated to be 1.5, 2.4, 11, 9.6, 4.8 and 3.0 µM for UGT1A1, -1A3, -1A7, -1A8, -1A10 and -2B7, respectively. In silico docking method was employed to demonstrate why T4 exerted stronger inhibition than T3 towards UGT1A1. Stronger hydrogen bonds and hydrophobic interaction between T4 and activity cavity of UGT1A1 than T3 contributed to stronger inhibition of T4 towards UGT1A1. 3. In conclusion, more clinical monitoring should be given for the patients with the elevation of T4 level due to stronger inhibition of UGT isoforms-catalyzed metabolism of drugs or endogenous substances by T4.

The inhibition of UDP-glucuronosyltransferases (UGTs) by vitamin A.

1. The exposed level of vitamin A in plasma might be exceeded due to the both inadvertent and clinical utilization. The adverse effects of vitamin A have been frequently reported, however, the mechanism remains unclear. The inhibition of vitamin A on the activity of UDP-glucuronosyltransferases (UGTs) was determined using in vitro incubation system to explain the adverse effects of vitamin A from a new perspective. 2. UGT supersomes catalyzed glucuronidation of 4-methylumbelliferone (4-MU), trifluoperazine (TFP), and cotinine was used as the probe reaction to evaluate the inhibition of vitamin A toward UGT isoforms, and 100 µM of vitamin A significantly inhibited the activity of all the tested UGT isoforms. Vitamin A exerted competitive inhibition on the activity of UGT1A1, 2B4, 2B7, and 2B15, and the inhibition kinetic parameters (Ki) were calculated to be 31.1, 16.8, 2.2, and 11.6 µM for UGT1A1, 2B4, 2B7, and 2B15. In silico docking method was used to try to elucidate the inhibition mechanism of vitamin A toward UGT2B7. The results showed the significant contribution of hydrogen bonds and hydrophobic interaction on the UGT2B7 inhibition by vitamin A. 3. The present study provides a new perspective for the adverse effects of vitamin A through reporting the inhibition of vitamin A on the activity of important phase II drug-metabolizing enzymes UGTs, which benefits our deep understanding of mechanism of vitamin A's adverse effects when high exposure of vitamin A occurs.

Role of the lipid-regulated NF-κB/IL-6/STAT3 axis in alpha-naphthyl isothiocyanate-induced liver injury.

Alpha-naphthyl isothiocyanate (ANIT)-induced liver damage is regarded as a useful model to study drug-induced cholestatic hepatitis. Ultra-performance liquid chromatography coupled with electrospray ionization quadrupole mass spectrometry (UPLC-ESI-QTOF MS)-based metabolomics revealed clues to the mechanism of ANIT-induced liver injury, which facilitates the elucidation of drug-induced liver toxicity. 1-Stearoyl-2-hydroxy-sn-glycero-3-phosphocholine (LPC 18:0) and 1-oleoyl-2-hydroxy-sn-glycero-3-phosphocholine (LPC 18:1) were significantly increased in serum from ANIT-treated mice, and this increase resulted from altered expression of genes encoding the lipid metabolism enzymes Chka and Scd1. ANIT also increased NF-κB/IL-6/STAT3 signaling, and in vitro luciferase reporter gene assays revealed that LPC 18:0 and LPC 18:1 can activate NF-κB in a concentration-dependent manner. Activation of PPARα through feeding mice a Wy-14,643-containing diet (0.1%) reduced ANIT-induced liver injury, as indicated by lowered ALT and AST levels, and liver histology. In conclusion, the present study demonstrated a role for the lipid-regulated NF-κB/IL-6/STAT3 axis in ANIT-induced hepatotoxicity, and that PPARα may be a potential therapeutic target for the prevention of drug-induced cholestatic liver injury.

The upregulated α-catulin expression was involved in head-neck squamous cell carcinogenesis by promoting proliferation, migration, invasion, and epithelial to mesenchymal transition.

Rho signaling component, α-catulin, is a cytoskeletal linker protein and plays an important role in apoptotic and senescence resistance, cytoskeletal reorganization, mobility, invasion, and epithelial to mesenchymal transition (EMT) of cancer cells. Here, we transfected α-catulin-expressing plasmid into head and neck squamous cell carcinoma (HNSCC) cell and examined the phenotypes and relevant molecules. α-catulin expression was detected on tissue microarray containing squamous epithelium, dysplasia, and cancer of head and neck by immunohistochemistry. It was found that α-catulin overexpression resulted in faster growth, migration and invasion, lower apoptosis, G2/M progression, and EMT than the mock and control (P < 0.05). α-catulin overexpression increased the expression of Cyclin E1, cdc2, survivin, Bcl-2, MMP-2, MMP-9, and N-cadherin but decreased the expression of Caspase-3 and E-cadherin by real-time PCR (P < 0.05). α-catulin expression was stronger in primary cancers than those in normal squamous epithelium and dysplasia (P < 0.05), but not correlated with aggressive behaviors or adverse prognosis of HNSCC patients (P > 0.05). Multivariate survival analysis showed that distant metastasis and TNM staging were independent prognostic factors for overall survival of the HNSCC patients (P < 0.05). These data indicated that upregulated expression of α-catulin protein might have impact on the tumorigenesis of HNSCC possibly by reducing apoptosis, enhancing proliferation, cell cycle progression, migration, invasion, and EMT. It might be regarded as a potential marker for head and neck carcinogenesis or a target of gene therapy for HNSCCs.

The Inhibition of UDP-Glucuronosyltransferase (UGT) Isoforms by Praeruptorin A and B.

Praeruptorin A (PA) and B (PB) are two important compounds isolated from Bai-hua Qian-hu and have been reported to exert multiple biochemical and pharmacological activities. The present study aims to determine the inhibition of PA and PB on the activity of important phase II drug-metabolizing enzymes uridine 5'-diphospho-glucuronosyltransferase (UGTs) isoforms. In vitro UGT incubation system was used to determine the inhibition potential of PA and PB on the activity of various UGT isoforms. In silico docking was performed to explain the inhibition difference between PA and PB towards the activity of UGT1A6. Inhibition behaviour was determined, and in vitro-in vivo extrapolation was performed by using the combination of in vitro inhibition kinetic parameter (Ki ) and in vivo exposure level of PA. Praeruptorin A (100 µM) exhibited the strongest inhibition on the activity of UGT1A6 and UGT2B7, with 97.8% and 90.1% activity inhibited by 100 µM of PA, respectively. In silico docking study indicates the significant contribution of hydrogen bond interaction towards the stronger inhibition of PA than PB towards UGT1A6. Praeruptorin A noncompetitively inhibited the activity of UGT1A6 and competitively inhibited the activity of UGT2B7. The inhibition kinetic parameter (Ki ) of PA towards UGT1A6 and UGT2B7 was calculated to be 1.2 and 3.3 µM, respectively. The [I]/Ki value was calculated to be 15.8 and 5.8 for the inhibition of PA on UGT1A6 and UGT2B7, indicating high inhibition potential of PA towards these two UGT isoforms in vivo. Therefore, closely monitoring the interaction between PA and drugs mainly undergoing UGT1A6 or UGT2B7-catalyzed metabolism is very necessary. Copyright © 2016 John Wiley & Sons, Ltd.

The clinicopathological significances and biological functions of parafibromin expression in head and neck squamous cell carcinomas.

Downregulated parafibromin expression is involved in the pathogenesis and progression of parathyroid, breast, gastric, colorectal, and lung cancers. To investigate the roles of parafibromin expression in tumorigenesis, progression, and prognostic evaluation of head and neck squamous cell carcinomas (HNSCCs), we transfected parafibromin-expressing plasmid into HNSCC cell and examined the phenotypes and their relevant molecules. Parafibromin expression was detected on tissue microarray containing squamous epithelium, dysplasia, and carcinoma of head and neck by immunohistochemistry. Parafibromin overexpression was found to suppress growth, migration, and invasion, and induce apoptosis, S arrest, and mesenchymal to epithelial transition (EMT), compared with the mock and control (P < 0.05). Both overexpression of Cyclin E1, Bax, and E-cadherin and hypoexpression of c-myc, Bcl-xL, and slug were detected in B88 transfectants, in comparison to mock and control by real-time PCR. Parafibromin expression was weaker in primary cancers than those in normal squamous tissue and dysplasia (P < 0.05), but stronger than the metastatic cancers in lymph node (P < 0.05). Parafibromin expression was negatively correlated with lymph node metastasis, tumor-node-metastasis (TNM) staging, but positively with human papillomavirus (HPV) positivity (P < 0.05). The HNSCCs in tongue showed more parafibromin expression than those in larynx (P < 0.05). There was stronger parafibromin expression in moderately-than poorly-differentiated carcinomas (P < 0.05). The significantly positive correlation was observed between parafibromin expression and relapse-free survival rate by Kaplan-Meier curves (P < 0.05). Cox's proportional hazard model indicated that distant metastasis and parafibromin expression were independent prognostic factors for overall and relapse-free survival of HNSCC, respectively (P < 0.05). These findings suggest that downregulated expression of parafibromin protein plays an important role in the pathogenesis, differentiation, and metastasis of HNSCCs possibly by inducing apoptosis, suppressing proliferation, cell cycle progression, migration, invasion, and EMT. Parafibromin expression is an independent factor for relapse-free survival of HNSCCs.

Association between Genetic Polymorphisms in DEFB1 and Susceptibility to Digestive Diseases.

BACKGROUND: Aberrant expression of defensins is implicated in the pathogenesis of digestive diseases. However, the contribution of specific defensins and the influence of their genetic polymorphisms on the progression of digestive diseases remain controversial. In the present meta-analysis, we investigated the association between DEFB1 SNPs and the susceptibility to digestive diseases. MATERIAL AND METHODS: Case-control studies that reported the correlation between DEFB1 SNPs and the susceptibility to digestive diseases were identified through electronic databases searches, and high-quality studies that satisfied our inclusion criteria were selected for this meta-analysis. Statistical analyses were performed utilizing STATA software version 12.0. RESULTS: The present meta-analysis revealed that patients with digestive diseases exhibited higher frequencies of the DEFB1 genetic variants rs11362G>A, rs1800972C>G, and rs1799946G>A compared to healthy controls under the allele model. Subgroup analysis based on country showed that the rs1800972C>G variant under allele model and rs1799946G>A are associated with the susceptibility to digestive diseases in Hungarian and Italian populations, respectively. Subgroup analysis based on disease type showed that: (1) rs11362G>A variant was strongly associated with severe acute pancreatitis (SAP) and chronic gastritis, (2) frequency of rs1800972C>G variant was higher in SAP subgroup, and (3) frequency of rs1799946G>A variant was positively associated with the susceptibility to Crohn's disease (CD) under the allele model and with SAP. CONCLUSIONS: Our meta-analysis provides evidence that DEFB1 genetic polymorphisms rs11362G>A, rs1800972C>G and rs1799946G>A are important contributing factors to the development of digestive diseases.

The role of RhoC in epithelial-to-mesenchymal transition of ovarian carcinoma cells.

BACKGROUND: RhoC is a small G protein/GTPase and involved in tumor mobility, invasion and metastasis. Previously, up-regulated RhoC expression is found to play an important role in ovarian carcinogenesis and subsequent progression by modulating proliferation, apoptosis, migration and invasion. METHODS: We transfected RhoC-expressing plasmid and RhoC siRNA into CAOV3 and OVCAR3 cells respectively. These cells and transfectants were exposed to vascular epithelial growth factor (VEGF), transforming growth factor (TGF)-ß1 or their receptor inhibitors with the phenotypes and their related-molecules examined. RESULTS: TGF-ß1R or VEGFR inhibitor suppressed the proliferation, migration, invasion and lamellipodia formation, the expression of N-cadherin, α-SMA, snail and Notch1 mRNA or protein, and enhanced E-cadherin mRNA and protein expression in CAOV3 and its RhoC-overexpressing transfectants, whereas both growth factors had the opposite effects in OVCAR3 cells and their RhoC-hypoexpressing transfectants. Ectopic RhoC expression enhanced migration, invasion, lamellipodia formation and the alteration in epithelial to mesenchymal transition (EMT) markers of CAOV3 cells regardless of the treatment of VEGFR or TGF-ß1R inhibitor, whereas RhoC knockdown resulted in the converse in OVCAR3 cells even with the exposure to VEGF or TGF-ß1. CONCLUSION: RhoC expression might be involved in EMT of ovarian epithelial carcinoma cells, stimulated by TGF-ß1 and VEGF.

Downregulated inhibitor of growth 3 (ING3) expression during colorectal carcinogenesis.

BACKGROUND & OBJECTIVES: ING3 (inhibitor of growth protein 3) overexpression decreased S-phase cell population and colony-forming efficiency, and induced apoptosis at a p53-mediated manner. The aim of this study was to investigate the clinicopathological and prognostic significance of ING3 expression in colorectal carcinogenesis and subsequent progression. METHODS: ING3 expression was examined by immunohistochemistry on tissue microarray containing colorectal non-neoplastic mucosa (NNM), adenoma and adenocarcinoma. Colorectal carcinoma tissue and cell lines were studied for ING3 expression by Western blot or RT-PCR. RESULTS: ING3 mRNA was differentially expressed in Colo201, Colo205, DLD-1, HCT-15, HCT-116, HT-29, KM-12, SW480, SW620 and WiDr cells. Carcinomas showed significantly lower ING3 expression than matched NNM at mRNA level (P< 0.05), but not at protein level. Immunohistochemically, ING3 expression was significantly decreased from NNM, adenoma to adenocarcinoma (P< 0.05). ING3 expression was not correlated with age, sex, tumour size, depth of invasion, lymphatic or venous invasion, lymph node metastasis, tumour- node- metastasis staging or differentiation. Kaplan-Meier analysis indicated that ING3 protein expression was not associated the prognosis of the patients with colorectal carcinoma (P< 0.05). INTERPRETATION & CONCLUSIONS: Our study showed that downregulated ING3 expression might play an important role in colorectal adenoma-adenocarcinoma sequence. Further studies are required to understand the mechanism.

KRT80 expression works as a biomarker and a target for differentiation in gastric cancer.

Keratin 80 (KRT80) is a filament protein that participates in cell differentiation and the integrity of the epithelial barrier. Here, KRT80 expression was higher in gastric cancer compared with normal mucosa at both mRNA and protein levels by bioinformatic analysis, qRT-PCR and Western blot (p<0.05), however, the methylation of KRT80 was lower than in normal mucosa (p<0.05). There was a negative relationship between promoter methylation and expression level of KRT80 gene in gastric cancer (p<0.05). KRT80 mRNA and protein expression was positively correlated with the differentiation of gastric cancer (p<0.05), while KRT80 methylation was negatively associated with gastric cancer differentiation and p53 mutation (p<0.05). The expression of KRT80 mRNA was positively linked to the short survival time of gastric cancers (p<0.05). The differential genes of KRT80 mRNA were involved in ligand-receptor interaction, estrogen signal pathway, peptidase, filament and cytoskeleton, keratinocyte differentiation, vitamin D receptor, muscle contraction, and B cell-mediated immunity (p<0.05). KRT80-related genes were classified into cell adhesion and junction, cadherin binding, skin and epidermis development, and so forth (p<0.05). KRT80 knockdown suppressed proliferation, anti-apoptosis, anti-pyroptosis, migration, invasion and epithelial-mesenchymal transition in gastric cancer cells (p<0.05). These findings indicated that up-regulated expression of KRT80 played a crucial part in gastric carcinogenesis, and might be considered as a biological marker for aggressive behaviors and poor prognosis. Its silencing might be used as an approach of target therapy for gastric cancer patients.

A model of in vitro UDP-glucuronosyltransferase inhibition by bile acids predicts possible metabolic disorders.

Increased levels of bile acids (BAs) due to the various hepatic diseases could interfere with the metabolism of xenobiotics, such as drugs, and endobiotics including steroid hormones. UDP-glucuronosyltransferases (UGTs) are involved in the conjugation and elimination of many xenobiotics and endogenous compounds. The present study sought to investigate the potential for inhibition of UGT enzymes by BAs. The results showed that taurolithocholic acid (TLCA) exhibited the strongest inhibition toward UGTs, followed by lithocholic acid. Structure-UGT inhibition relationships of BAs were examined and in vitro-in vivo extrapolation performed by using in vitro inhibition kinetic parameters (Ki) in combination with calculated in vivo levels of TLCA. Substitution of a hydrogen with a hydroxyl group in the R1, R3, R4, R5 sites of BAs significantly weakens their inhibition ability toward most UGTs. The in vivo inhibition by TLCA toward UGT forms was determined with following orders of potency: UGT1A4 > UGT2B7 > UGT1A3 > UGT1A1 ∼ UGT1A7 ∼ UGT1A10 ∼ UGT2B15. In conclusion, these studies suggest that disrupted homeostasis of BAs, notably taurolithocholic acid, found in various diseases such as cholestasis, could lead to altered metabolism of xenobiotics and endobiotics through inhibition of UGT enzymes.

Structure-inhibition relationship of ginsenosides towards UDP-glucuronosyltransferases (UGTs).

The wide utilization of ginseng provides the high risk of herb-drug interaction (HDI) with many clinical drugs. The inhibition of ginsenosides towards drug-metabolizing enzymes (DMEs) has been regarded as an important reason for herb-drug interaction (HDI). Compared with the deep studies on the ginsenosides' inhibition towards cytochrome P450 (CYP), the inhibition of ginsenosides towards the important phase II enzymes UDP-glucuronosyltransferases (UGTs) remains to be unclear. The present study aims to evaluate the inhibition behavior of ginsenosides towards important UGT isoforms located in the liver and intestine using in vitro methods. The recombinant UGT isoform-catalyzed 4-methylumbelliferone (4-MU) glucuronidation reaction was employed as in vitro probe reaction. The results showed that structure-dependent inhibition existed for the inhibition of ginsenosides towards UGT isoforms. To clarify the possibility of in vivo herb-drug interaction induced by this kind of inhibition, the ginsenoside Rg(3) was selected as an example, and the inhibition kinetic type and parameters (K(i)) were determined. Rg(3) competitively inhibited UGT1A7, 2B7 and 2B15-catalyzed 4-MU glucuronidation reaction, and exerted noncompetitive inhibition towards UGT1A8-catalyzed 4-MU glucuronidation. The inhibition parameters (K(i) values) were calculated to be 22.6, 7.9, 1.9, and 2.0µM for UGT1A7, 1A8, 2B7 and 2B15. Using human maximum plasma concentration of Rg(3) (400ng/ml (0.5µM)) after intramuscular injection of 60mg Rg(3), the area under the plasma concentration-time curve (AUC) was extrapolated to increase by 2.2%, 6.3%, 26.3%, and 25% for the co-administered drugs completely undergoing the metabolism catalyzed by UGT1A7, 1A8, 2B7 and 2B15, respectively. All these results indicated that the ginsenosides' inhibition towards UGT isoforms might be an important reason for ginseng-drug interaction.

Investigation of the in vitro metabolism of evodiamine: characterization of metabolites and involved cytochrome p450 isoforms.

Evodiamine is the main active alkaloid of Evodia rutaecarpa (E. rutaecarpa) and has been demonstrated to exhibit many pharmacological activities including vasorelaxation, uterotonic action, anoxia and control of body temperature. The present study focused on the metabolism of evodiamine. Human and phenobarbital-induced rat liver microsomal incubation of evodiamine in the presence of NADPH resulted in the formation of five major metabolites (M-1, M-2, M-3, M-4, M-5). Four metabolites (M-1, M-2, M-3 and M-5) were identified to mono-hydroxylated evodiamine and one metabolite (M-4) was identified to be N-demethylated evodiamine. CYP3A4, CYP2C9 and CYP1A2 were identified to be the main CYP isoforms involved in the metabolism of evodiamine in human liver microsomes. Finding new metabolites can help us decipher novel substance basis of efficiency and toxicity. Elucidation of drug metabolizing enzymes will facilitate explaining the individual difference for response to the same drugs or herbs and the potential drug-drug interaction or herb-drug interaction. Taken together, these results are of significance for better understanding the pharmacokinetic behaviour of evodiamine and helpful for clinical application of evodiamine and E. rutaecarpa.

Glycyrrhetinic acid exhibits strong inhibitory effects towards UDP-glucuronosyltransferase (UGT) 1A3 and 2B7.

The aim of the present study is to evaluate the inhibitory effects of liver UDP-glucuronosyltransferases (UGTs) by glycyrrhizic acid and glycyrrhetinic acid, which are the bioactive ingredients isolated from licorice. The results showed that glycyrrhetinic acid exhibited stronger inhibition towards all the tested UGT isoforms, indicating that the deglycosylation process played an important role in the inhibitory potential towards UGT isoforms. Furthermore, the inhibition kinetic type and parameters were determined for the inhibition of glycyrrhetinic acid towards UGT1A3 and UGT2B7. Data fitting using Dixon and Lineweaver-Burk plots demonstrated that the inhibition of UGT1A3 and UGT2B7 by glycyrrhetinic acid was best fit to competitive and noncompetitive type, respectively. The second plot using the slopes from Lineweaver-Burk plots versus glycyrrhetinic acid concentrations was employed to calculate the inhibition kinetic parameters (K(i)), and the values were calculated to be 0.2 and 1.7 µM for UGT1A3 and UGT2B7, respectively. All these results remind us the possibility of UGT inhibition-based herb-drug interaction. However, the explanation of these in vitro parameters should be paid more caution due to complicated factors, including the probe substrate-dependent UGT inhibition behaviour, environmental factors affecting the abundance of herbs' ingredients, and individual difference of pharmacokinetic factors.

Arbidol exhibits strong inhibition towards UDP-glucuronosyltransferase (UGT) 1A9 and 2B7.

The aim of the present study was to investigate arbidol's inhibition towards UDP-glucuronosyltransferase (UGT) 1A9 and 2B7. The nonspecific probe substrate 4-methylumbelliferone (4-MU) and recombinant UGT enzymes (UGT1A9, UGT2B7) were firstly used to evaluate the inhibition of arbidol towards UGT1A9 and UGT2B7. Furthermore, specific substrates of UGT1A9 and UGT2B7 propofol and zidovudine (AZT) were used to determine the inhibition of arbidol towards UGT1A9 and UGT2B7. Inhibition type and inhibition kinetic parameters (Ki) were determined. In vitro-in vivo extrapolation (IV-IVE) was performed to predict in vivo DDI magnitude induced by arbidol. Arbidol was demonstrated to exhibit competitive inhibition towards UGT1A9 and UGT2B7 without substate-dependent behaviour. The inhibition kinetic parameters (Ki) were calculated to be 0.5 microM, 3.5 microM, 2.8 microM, 29.7 microM for UGT2B7-mediated 4-MU glucuronidation, UGT1A9-mediated 4-MU glucuronidation, UGT2B7-mediated AZT glucuronidation, and UGT1A9-mediated propofol glucuronidation, respectively. Using these parameters, the in vivo alteration of area under of concentration-time curve (AUC) was calculated to be 156%, 22%, 28% and 2.6%, respectively. Given that arbidol exhibits strong inhibition towards UGT1A9 and UGT2B7, clinical monitoring should be given when arbidol was co-administered with drugs mainly undergoing UGT1A9, UGT2B7-mediated metabolism.

Oncogenic roles of GPR176 in breast cancer: a potential marker of aggressiveness and a potential target of gene therapy.

BACKGROUND: Belonging to the G-protein coupled receptor 1 family, G protein-coupled receptor 176 (GPR176) is associated with the Gz/Gx G-protein subclass and is capable of decreasing cAMP production. METHODS: GPR176 expression was detected by qRT-PCR, bioinformatics analysis, Western blot and immunohistochemistry, and compared with clinicopathological characteristics of breast cancer. GPR176-related genes and pathways were subjected to bioinformatic analysis. We also explored the effects of GPR176 on the phenotypes of breast cancer cells. RESULTS: Lower expression of GPR176 mRNA was seen in breast cancer than in normal tissues, but the opposite pattern was found for its protein (p < 0.05). GPR176 mRNA was associated with female sex, low T staging, non-Her-2+ subtypes, non-mutant p53 status in breast cancer (p < 0.05). GPR176 methylation was negatively correlated with its mRNA level and T staging in breast cancer, and was higher in breast cancer than normal tissues (p < 0.05). GPR176 protein expression was positively correlated with older age, small tumor size, and non-luminal-B subtype of breast cancers (p < 0.05). The differential genes of GPR176 were involved in receptor-ligand interaction, RNA maturation, and so forth (p < 0.05). GPR176-related genes were categorized into cell mobility, membrane structure, and so on (p < 0.05). GPR176 knockdown weakened the proliferation, glucose catabolism, anti-apoptosis, anti-pyroptosis, migration, invasion, and epithelial-mesenchymal transition of breast cancer cells. CONCLUSION: These results indicate that GPR176 might be involved in the tumorigenesis and subsequent progression of breast cancer by deteriorating aggressive phenotypes. It might be utilized as a potential biomarker to indicate the aggressive behaviors and poor prognosis of breast cancer and a potential target of genetic therapy.

Regenerating gene 4 promotes chemoresistance of colorectal cancer by affecting lipid droplet synthesis and assembly.

BACKGROUND: Regenerating gene 4 (REG4) has been proved to be carcinogenic in some cancers, but its manifestation and possible carcinogenic mechanisms in colorectal cancer (CRC) have not yet been elucidated. Our previous study found that the drug resistance of CRC cells may be closely linked to their fat metabolism. AIM: To explore the role of REG4 in CRC and its association with lipid droplet formation and chemoresistance. METHODS: We conducted a meta-analysis and bioinformatics and pathological analyses of REG4 expression in CRC. The effects of REG4 on the phenotypes and related protein expression were also investigated in CRC cells. We detected the impacts of REG4 on the chemoresistance and lipid droplet formation in CRC cells. Finally, we analyzed how REG4 regulated the transcription and proteasomal degradation of lipogenic enzymes in CRC cells. RESULTS: Compared to normal mucosa, REG4 mRNA expression was high in CRC (P < 0.05) but protein expression was low. An inverse correlation existed between lymph node and distant metastases, tumor-node-metastasis staging or short overall survival and REG4 mRNA overexpression (P < 0.05), but vice versa for REG4 protein expression. REG4-related genes included: Chemokine activity; taste receptors; protein-DNA and DNA packing complexes; nucleosomes and chromatin; generation of second messenger molecules; programmed cell death signals; epigenetic regulation and DNA methylation; transcription repression and activation by DNA binding; insulin signaling pathway; sugar metabolism and transfer; and neurotransmitter receptors (P < 0.05). REG4 exposure or overexpression promoted proliferation, antiapoptosis, migration, and invasion of DLD-1 cells in an autocrine or paracrine manner by activating the epidermal growth factor receptor-phosphoinositide 3-kinase-Akt-nuclear factor-κB pathway. REG4 was involved in chemoresistance not through de novo lipogenesis, but lipid droplet assembly. REG4 inhibited the transcription of acetyl-CoA carboxylase 1 (ACC1) and ATP-citrate lyase (ACLY) by disassociating the complex formation of anti-acetyl (AC)-acetyl-histone 3-AC-histone 4-inhibitor of growth protein-5-si histone deacetylase;-sterol-regulatory element binding protein 1 in their promoters and induced proteasomal degradation of ACC1 or ACLY. CONCLUSION: REG4 may be involved in chemoresistance through lipid droplet assembly. REG4 reduces expression of de novo lipid synthesis key enzymes by inhibiting transcription and promoting ubiquitination-mediated proteasomal degradation.

Long-chain saturated fatty acids and its interaction with insulin resistance and the risk of nonalcoholic fatty liver disease in type 2 diabetes in Chinese.

Introduction: This study aimed to explore relationships between long-chain saturated fatty acids (LSFAs) and nonalcoholic fatty liver disease (NAFLD) in patients with type 2 diabetes (T2D); and whether insulin action had an interactive effect with LSFAs on NAFLD progression. Methods: From April 2018 to April 2019, we extracted the electronic medical records of 481 patients with T2D who meet the inclusion and exclusion criteria from the Second Affiliated Hospital of Dalian Medical University. Ultrasound was used to estimate NAFLD at admission. Logistic regression analysis were used to estimate odds ratios (OR) and 95% confidence intervals (CI). The additive interaction was carried out to estimate interactions between LSFAs and insulin resistance (IR) in NAFLD patients with T2D. Results: Myristic acid (14:0) and palmitic acid (16:0) were positively associated with the risk of NAFLD (OR for myristic acid (14:0): 7.516, 3.557-15.882 and OR for palmitic acid (16:0): 4.071, 1.987-8.343, respectively). After adjustment for traditional risk factors, these associations were slightly attenuated but still highly significant. Co-presence of myristic acid (14:0)>72.83 µmol/L and IR>4.89 greatly increased OR of NAFLD to 9.691 (4.113-22.833). Similarly, co-presence of palmitic acid (16:0)>3745.43µmol/L and IR>4.89 greatly increased OR of NAFLD to 6.518(2.860-14.854). However, stearic acid (18:0) and risk of NAFLD have no association. Moreover, there was no association between very-long-chain SFAs (VLSFAs) and risk of NAFLD. Discussion: Myristic acid (14:0) and palmitic acid (16:0) were positively associated with the risk of NAFLD in T2D patients in China. High IR amplified the effect of high myristic acid (14:0) and high palmitic acid (16:0) on NAFLD.