ABSTRACT
AIMS: Hepatitis C virus (HCV) relies on the viral and host factors to complete its life cycle. It has evolved to profit from Akt activation at some stage in its life cycle through various mechanisms, notably by activating lipogenesis, which is crucial for infectious virions production. MATERIALS AND METHODS: By employing an Akt-specific inhibitor, the impact of Akt on intracellular and extracellular infectivity was investigated. To ascertain the role of Akt in the HCV life cycle, the two-part cell culture-derived HCV infection protocol utilizing Akt1 small interfering RNAs (siRNAs) was implemented. The impact of Akt1 on intracellular HCV transition was determined using membrane flotation assay and proximity ligation assay coupled with Anti-Rab7 immunoprecipitation and immunofluorescence. KEY FINDINGS: Akt1 silencing reduced infectious virions release to a degree comparable to that of ApoE, a host component involved in the HCV assembly and release, suggesting Akt1 was critical in the late stage of the HCV life cycle. Extracellular infectivity of HCV was inhibited by brefeldin A, and the inhibitory effect was augmented by Akt1 silencing and partially restored by ectopic Akt1 expression. Immunofluorescence revealed that Akt1 inhibition suppressed the interaction between HCV core protein and lipid droplet. Akt1 silencing impeded the transition of HCV from the endoplasmic reticulum to the endosome and hence inhibited the secretion of HCV infectious virions from the late endosome. SIGNIFICANCE: Our study demonstrates that Akt1 has an impact on the lipogenesis pathway and plays a critical role in the assembly and secretion of infectious HCV.
Subject(s)
Hepacivirus , Hepatitis C , Humans , Endoplasmic Reticulum/metabolism , Endosomes , Hepacivirus/metabolism , Hepatitis C/genetics , Proto-Oncogene Proteins c-akt/metabolism , RNA, Small Interfering/metabolism , Virion , Virus Assembly/physiologyABSTRACT
Hepatitis C virus (HCV) infection is recognized as a major causative agent of chronic hepatitis, cirrhosis, and hepatocellular carcinoma. HCV non-structural protein 5A (NS5A) is a dimeric phosphoprotein with a hyperphosphorylated form to act as a switch that regulates HCV replication and assembly. NS5A inhibitors have been utilized as the scaffold for combination therapy of direct-acting antiviral agents (DAA). However, the mode of action of NS5A inhibitors is still unclear due to the lack of mechanistic detail regarding NS5A phosphorylation and dimerization in the HCV life cycle. It has been demonstrated that phosphorylation of NS5A at Ser235 is essential for RNA replication of the JFH1 strain. In this report, we found that NS5A phosphomimetic Ser235 substitution (Ser-to-Asp mutation) formed a dimer that was resistant to disruption by NS5A inhibitors as was the NS5A resistance-associated substitution Y93H. Phosphorylation of NS5A at Ser235 residue was required for the interaction of two NS5A-WT molecules in JFH1-based cell culture system but not absolutely required for dimerization of the NS5A-Y93H mutant. Interestingly, HCV nonstructural proteins from the subgenomic replicon NS3-5A was required for NS5A-WT dimerization but not required for NS5A-Y93H dimerization. Our data suggest that spontaneous Ser235 phosphorylation of NS5A and ensuing dimerization account for resistance of the JFH1/NS5A-Y93H mutant to NS5A inhibitors.
Subject(s)
Hepatitis C, Chronic , Hepatitis C , Liver Neoplasms , Humans , Hepacivirus/metabolism , Phosphorylation , Antiviral Agents/therapeutic use , Dimerization , Hepatitis C, Chronic/drug therapy , Hepatitis C/drug therapy , Liver Neoplasms/drug therapy , Drug Resistance , Viral Nonstructural Proteins/genetics , Viral Nonstructural Proteins/metabolismABSTRACT
HCV NS5A is a dimeric phosphoprotein involved in HCV replication. NS5A inhibitors are among direct-acting antivirals (DAA) for HCV therapy. The Y93H mutant of NS5A is resistant to NS5A inhibitors, but the precise mechanism remains unclear. In this report, we proposed a Ser38-His93-Asn91 triad to dissect the mechanism. Using pymol 1.3 software, the homology structure of JFH1 NS5A was determined based on the dimer structure of genotype 1b extracted from the database Protein DataBank (www.ebi.ac.uk/pdbsum) with codes 1ZH1 and 3FQM/3FQQ. FLAG-NS5A-WT failed to form dimer in the absence of nonstructural proteins from subgenomic replicon (NS3-5A); however, FLAG-NS5A-Y93H was able to form dimer without the aid of NS3-5A. The Ser38-His93-Asn91 triad in the dimer of the Y93H variant predicts a structural crash of the cleft receiving the NS5A inhibitor daclatasvir. The dimerization assay revealed that the existence of JFH1-NS5A-1ZH1 and -3FQM homology dimers depended on each other for existence and that both NS5A-WT 1ZH1 and 3FQM dimers cooperated to facilitate RNA replication. However, NS5A-Y93H 1ZH1 alone could form dimer and conduct RNA replication in the absence of the 3FQM structure. In conclusion, this study provides novel insight into the functional significance of the Ser38-His93-Asn91 triad in resistance of the Y93H variant to NS5A inhibitors.
Subject(s)
Antiviral Agents , Hepatitis C, Chronic , Humans , Antiviral Agents/pharmacology , Hepatitis C, Chronic/drug therapy , Genotype , Hepacivirus/genetics , Viral Nonstructural Proteins/genetics , Drug Resistance, Viral/geneticsABSTRACT
AIMS AND OBJECTIVES: To investigate the factors affecting quality of life in healthcare providers who care for patients with COVID-19. BACKGROUND: Healthcare providers caring for COVID-19 patients during the pandemic suffered a deterioration in their quality of life. Several studies have explored their psychological impact of working with COVID patients, but none have examined the causes of this deterioration. DESIGN: A cross-sectional study. METHODS: In the current study, the authors investigated the factors affecting quality of life in 293 healthcare providers recruited from a medical centre in northern Taiwan who had recently cared for patients with suspected or confirmed COVID-19 by analysing their responses to an online self-report questionnaire, using bivariate correlations and structural equation modelling. Reporting of this research adheres to the STROBE guideline. RESULTS: The study identified an important sequence of factors that mediated the effects of perceived success of epidemic prevention policies, family relations problems and education level on quality of life in a sample of healthcare workers caring for COVID-19 patients. The mediators were use of approach-oriented coping strategies and current mental health status. Specifically, use of approach-oriented coping strategies was found to directly cause improved quality of life and indirectly cause improved mental health, whereas use of avoidant coping strategies was found to directly cause worsening of mental health. Poor mental health predicted poor quality of life. CONCLUSIONS: Results suggest that implementation of sound epidemic prevention policies that promote adoption of approach-oriented coping behaviour should lead to a better quality of life in the future for healthcare providers working in challenging circumstances. RELEVANCE TO CLINICAL PRACTICE: Assessment of these policies as well as the providers' family relations are necessary first steps to improving the success of approach-oriented coping behaviour in this population, which in turn can improve their mental health and quality of life. PATIENT OR PUBLIC CONTRIBUTION: Neither patients nor members of the public were involved in the design or execution of the study.
Subject(s)
COVID-19 , Humans , COVID-19/epidemiology , Quality of Life , Cross-Sectional Studies , Health Personnel/psychology , PandemicsABSTRACT
BACKGROUND: Proton pump inhibitors (PPIs), such as esomeprazole, pantoprazole, dexlansoprazole, and rabeprazole, are one of the most commonly prescribed medications. Several studies have linked the long-term use of PPIs to a potentially increased risk of gastric cancer. Therefore, this study aimed to determine the underlying mechanism of PPI-mediated gastric cancer. METHODS: Lysosomes were isolated using immunoprecipitation. The inhibition of vacuolar-type ATPase (V-ATPase) by PPIs was assayed using a PiColorLock Gold Phosphate Detection System. PPI-induced lysosomal stress was analyzed using transcription factor EB (TFEB) nuclear translocation. PPI-induced endoplasmic reticulum (ER) stress was analyzed using the expression of protein kinase RNA-like endoplasmic reticulum kinase (PERK), inositol-requiring enzyme 1 (IRE1), and activating transcription factor 6 (ATF6). Finally, reactive oxygen species (ROS) removal was determined using the activity of superoxide dismutase (SOD). RESULTS: PPIs caused a 70% inhibition of V-ATPase activity at 20 µM, leading to lysosomal stress through TFEB nuclear translocation; ER stress by inducing the expression of PERK, IRE1, and ATF6; and enhanced SOD activity for ROS removal. CONCLUSION: The long-term use of PPIs inhibits lysosomal V-ATPase, leading to ER stress and ROS accumulation, which may result in an increased risk of gastric cancer. Because lysosomes and the ER are common organelles in cells, physicians prescribing PPIs for gastroesophageal reflux and peptic ulcer diseases should pay more attention to the general effects of these agents on the human body.
Subject(s)
Endoplasmic Reticulum Stress , Proton Pump Inhibitors , Vacuolar Proton-Translocating ATPases , Activating Transcription Factor 6/metabolism , Dexlansoprazole/adverse effects , Esomeprazole/adverse effects , Humans , Pantoprazole/adverse effects , Protein Serine-Threonine Kinases/metabolism , Proton Pump Inhibitors/adverse effects , Rabeprazole/adverse effects , Reactive Oxygen Species/metabolism , Stomach Neoplasms/chemically induced , Superoxide Dismutase/metabolism , Vacuolar Proton-Translocating ATPases/metabolismABSTRACT
Worsened lipid profiles were observed in chronic hepatitis C (CHC) patients during direct-acting antivirals (DAAs) treatment, among which combination drugs confounded the effect of individual ingredient on lipid. Tenofovir alafenamide (TAF) also worsened lipid profiles in HIV patients. Structural similarity between sofosbuvir (SOF) and TAF prompted us to investigate rapid increase in total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) in CHC patients treated with SOF-based DAAs. A retrospective study was performed to analyze 487 CHC patients receiving DAAs with SVR12. Relative risks on elevating TC and LDL-C were analyzed by logistic regression to determine SOF-based over non-SOF-based regimens. TC or LDL-C levels at baseline, week-4 and SVR12 were compared by Wilcoxon matched-pairs signed rank test. Week 4 or SVR12 to baseline ratios of serum TC or LDL-C between regimens were compared by Mann-Whitney's test. 487 patients were treated with Harvoni (SOF-based, 206 patients), Epclusa (SOF-based, 124 patients), Maviret (non-SOF-based, 122 patients), or Zepatier (non-SOF-based, 35 patients). At week 4 during drug treatment, Harvoni, Epclusa, and Maviret induced statistically significant elevation of TC and LDL-C, but Zepatier did not. SOF-based regimens had 2.72-fold higher relative risk (RR) causing 10% elevation of TC (95% CI 1.84-4.02, p < 0.001) and 2.04-fold higher RR causing 10% elevation of LDL-C (95% CI 1.39-3.01, p < 0.001) than non-SOF-based DAAs. SOF-based DAAs were associated with significantly larger amplitude of increases in TC and LDL-C than non-SOF-based DAAs during the initial 4 weeks of treatment, but the increases were not sustained to SVR12.
Subject(s)
Cholesterol, LDL , HIV Infections , Hepatitis C, Chronic , Sofosbuvir , Antiviral Agents/pharmacology , Cholesterol/metabolism , Cholesterol, LDL/drug effects , Cholesterol, LDL/metabolism , Drug Therapy, Combination , Genotype , HIV Infections/drug therapy , Hepacivirus , Hepatitis C, Chronic/drug therapy , Humans , Retrospective Studies , Ribavirin/pharmacology , Sofosbuvir/pharmacology , Treatment OutcomeABSTRACT
BACKGROUND: Previous studies reported worsened lipid profiles in patients infected with hepatitis C virus (HCV) during direct-acting antivirals (DAAs) treatment. This study aimed to investigate the effect of sofosbuvir (SOF)-based DAAs on changes in low-density lipoprotein (LDL) in HCV patients. METHODS: A systematic review of articles published before 31 May 2021 was conducted by searching MEDLINE, Cochrane Library, EMBASE, and CINAHL Plus. Eligible studies were those comparing SOF-based DAAs and non-SOF DAAs for HCV patients and providing numerical data for changes in LDL. Risk of Bias in Non-randomized Studies- of Interventions was used for assessing risk of bias, and meta-analysis was performed for changes in LDL. RESULTS: Six studies comprising 1248 patients were included, 848 patients treated with SOF-based DAAs and 400 patients with non-SOF DAAs vs. SOF-based DAAs group had significantly greater increases in LDL from baseline to week 4 than non-SOF DAAs group (P = 0.001). However, changes in LDL from baseline to the end of treatment (P = 0.060), to post-treatment week 12 (P = 0.263), and to post-treatment week 24 (P = 0.319) did not significantly differ between the two groups. Further comparison of SOF/ledipasvir with asunaprevir/daclatasvir revealed a similar trend in changes in LDL. CONCLUSIONS: For HCV patients, SOF-based DAA regimens were associated with rapid and significant increases in LDL during the initial 4 weeks of treatment, and the changes did not sustain after the end of treatment. Potential mechanism might be related to the phosphoramidate side chain of SOF.
Subject(s)
Hepatitis C, Chronic , Hepatitis C , Antiviral Agents/therapeutic use , Drug Therapy, Combination , Genotype , Hepacivirus , Hepatitis C/drug therapy , Hepatitis C, Chronic/drug therapy , Humans , Lipoproteins, LDL , Ribavirin/therapeutic use , Sofosbuvir/therapeutic use , Sustained Virologic Response , Treatment OutcomeABSTRACT
BACKGROUND: Hepatic decompensation is a fatal on-treatment side effect during chronic hepatitis C treatment with paritaprevir/ritonavir/ombitasvir and dasabuvir (PrOD). Prompt bilirubin testing can reveal hepatic failure in susceptible patients, and clinical parameters precipitating early elevation of bilirubin can warn clinicians to avoid PrOD prescription. METHODS: This retrospective study included 169 Hepatitis C virus (HCV)-genotype 1b patients who underwent a 12-week course of PrOD with or without ribavirin. Laboratory data underwent χ analysis with Fisher's exact test to determine the precipitating factors causing hyperbilirubinemia in patients who had received 1 week of treatment. RESULTS: Sustained viral response was achieved in 164 patients (97.0%). Total bilirubin was ≥2 mg/dL (21.3%) in 36 patients after 1 week of treatment. Pretreatment white blood cell (WBC) <4500/µL and platelet <100,000/µL correlated with total bilirubin ≥2 mg/dL (relative risk [RR]: 21.64, 95% CI: 5.23-89.64, p < 0.001) after 1 week of treatment. Pretreatment platelet ≥100 000/µL and WBC <4500/µL correlated with direct bilirubin ≥0.45 mg/dL (RR: 6.56, 95% CI: 1.42-30.38, p = 0.016) and indirect bilirubin ≥0.6 mg/dL (RR: 4.77, 95% CI: 1.03-22.15, p = 0.046). Pretreatment platelet <100,000/µL with F3/F4 fibrosis correlated with first week total bilirubin ≥2 mg/dL (RR: 3.57, 95% CI: 1.35-9.09, p = 0.010). CONCLUSION: PrOD is an effective antiviral regimen for HCV genotype 1b patients. Total bilirubin ≥2 mg/dL after 1 week of treatment serves as an early warning of irreversible progression toward hepatic decompensation, and the current study provides a guide by which to monitor chronic hepatitis C patients undergoing PrOD treatment.
Subject(s)
Antiviral Agents/adverse effects , Hepatitis C, Chronic/complications , Hyperbilirubinemia/chemically induced , 2-Naphthylamine/adverse effects , 2-Naphthylamine/therapeutic use , Adult , Aged , Aged, 80 and over , Anilides/adverse effects , Anilides/therapeutic use , Antiviral Agents/therapeutic use , Cyclopropanes/adverse effects , Cyclopropanes/therapeutic use , Female , Hepatitis C, Chronic/drug therapy , Humans , Lactams, Macrocyclic/adverse effects , Lactams, Macrocyclic/therapeutic use , Male , Middle Aged , Precipitating Factors , Proline/adverse effects , Proline/analogs & derivatives , Proline/therapeutic use , Retrospective Studies , Ribavirin/adverse effects , Ritonavir/adverse effects , Ritonavir/therapeutic use , Sulfonamides/adverse effects , Sulfonamides/therapeutic use , Taiwan , Uracil/adverse effects , Uracil/analogs & derivatives , Uracil/therapeutic use , Valine/adverse effects , Valine/therapeutic useABSTRACT
BACKGROUND: Hepatitis C virus (HCV) is a major causative agent of chronic hepatitis, cirrhosis, and hepatocellular carcinoma. The rapid progress in the development of direct-acting antivirals has greatly elevated the cure rate to ≥95% in recent years. However, the high cost of treatment is not affordable to patients in some countries, necessitating the development of less expensive treatment. METHODS: We adopted a cell culture-derived HCV system to screen a library of the pure compounds extracted from herbs deposited in the chemical bank of the National Research Institute of Chinese Medicine, Taiwan. RESULTS: We found that saikosaponin B2 inhibited viral entry, replication, and translation. Saikosaponin B2 is a plant glycoside and a component of xiao-chai-hu-tang, a traditional Chinese herbal medicine extracted from the roots of Bupleurum falcatum. It also inhibited daclatasvir-resistant mutant strains of HCV, especially in combination with daclatasvir. CONCLUSION: Our results may aid the development of a new combination therapy useful for patients with HCV who are intolerant or refractory to the currently available medications, including pegylated interferon and direct-acting antiviral agents.
Subject(s)
Antiviral Agents/pharmacology , Hepatitis C/drug therapy , Imidazoles/pharmacology , Oleanolic Acid/analogs & derivatives , Saponins/pharmacology , Carbamates , Cells, Cultured , Drug Resistance, Viral , Drug Therapy, Combination , Hepacivirus/drug effects , Humans , Imidazoles/administration & dosage , Oleanolic Acid/administration & dosage , Oleanolic Acid/pharmacology , Pyrrolidines , Saponins/administration & dosage , Valine/analogs & derivatives , Viral Nonstructural Proteins/antagonists & inhibitors , Viral Nonstructural Proteins/genetics , Virus Replication/drug effectsABSTRACT
Hepatitis C virus (HCV) is recognized as a major causative agent of chronic hepatitis, cirrhosis, and hepatocellular carcinoma. Despite rapid progress in the development of direct-acting antivirals (DAA) against HCV infection in recent years, cost-effective antiviral drugs with more affordable prices still need to be developed. In this study, we screened a library of natural compounds to identify natural HCV inhibitors. The library of the pure compounds extracted from Chinese herbs deposited in the chemical bank of National Research Institute of Chinese Medicine (NRICM), Taiwan was screened in the cell culture-derived HCV (HCVcc) system. We identified the flavone or flavan-based compounds amentoflavone, 7,4[Formula: see text]-dihydroxyflavanone, and orobol with the inhibition of viral entry, replication, and translation of the HCV life cycle. Amentoflavone and orobol also showed inhibitory effects on resistant-associated variants to the NS5A inhibitor daclatasvir. The results of this study have the potential to benefit patients who are intolerant to the adverse effect of pegylated interferon or who harbor resistant strains refractory to treatment by current direct-acting antiviral agents.
Subject(s)
Antiviral Agents/pharmacology , Biflavonoids/pharmacology , Drug Resistance, Viral/drug effects , Drugs, Chinese Herbal/chemistry , Flavonoids/pharmacology , Hepacivirus/drug effects , Imidazoles/pharmacology , Biflavonoids/isolation & purification , Carbamates , Cell Line, Tumor , Cell Survival/drug effects , Cells, Cultured , Drug Evaluation, Preclinical , Flavonoids/isolation & purification , Hepacivirus/pathogenicity , Hepacivirus/physiology , Humans , Phytotherapy , Pyrrolidines , Valine/analogs & derivatives , Virus Internalization/drug effects , Virus Replication/drug effectsABSTRACT
Gemcitabine and capecitabine are two effective anticancer agents against solid tumors. The pharmacological mechanisms have been known as incorporation into DNA and thereby inhibition of DNA synthesis. When used as metronomic chemotherapy, they may inhibit angiogenesis and induce immunity. In our previous study, we showed that low-dose gemcitabine caused telomere shortening by stabilizing TRF2 that was required for XPF-dependent telomere loss. In this report, we established a SKOV3.ip1 ascites cell model. Tumor-bearing mice were treated with low-dose gemcitabine (GEM) or capecitabine (CAP). Both GEM and CAP caused telomere shortening and increased expression of TRF2 with improved ascites in nude mice and decreased in vitro clonogenic activity. TRF2 knockdown altered telomeres to a shortened but new status that may evade XPF-dependent telomere loss and conferred resistance of SKOV3.ip1 ascites cells to low-dose GEM and CAP. Our study provides a new mechanism of metronomic chemotherapy i.e. TRF2 is required for metronomic therapeutic effects of gemcitabine and capecitabine.
Subject(s)
Administration, Metronomic , Capecitabine/pharmacology , Deoxycytidine/analogs & derivatives , Drug Resistance/drug effects , Gene Expression Regulation, Neoplastic/drug effects , Ovarian Neoplasms/drug therapy , Telomere Homeostasis/drug effects , Telomeric Repeat Binding Protein 2/biosynthesis , Animals , Cell Line, Tumor , Deoxycytidine/pharmacology , Drug Resistance/genetics , Female , Humans , Mice , Mice, Nude , Neoplasm Proteins , Ovarian Neoplasms/genetics , Ovarian Neoplasms/metabolism , Telomere Homeostasis/genetics , Telomeric Repeat Binding Protein 2/genetics , GemcitabineABSTRACT
Penile transplantation is an emerging option for patients with severe genital defects not amenable to traditional reconstructive options. In this article, we discuss the burgeoning problem of severe male genitourinary trauma in the military, the limitations of traditional reconstructive options in addressing these problems, and the potential for penile transplantation to provide improved outcomes. We also review the preclinical research and limited worldwide experience with penile transplantation to date, including lessons learned, and discuss the many important technical, logistical, and ethical considerations pertaining to penile transplantation that must be addressed to maximize the likelihood of successful implementation.
Subject(s)
Penile Transplantation , Humans , Male , Penis/physiology , War-Related Injuries/surgeryABSTRACT
Infection with cagA-positive Helicobacter pylori is associated with a higher risk of gastric cancer. The cagA gene product, CagA, is translocated into gastric epithelial cells and perturbs host cellular biological functions. Etoposide, a topoisomerase II inhibitor widely used to couple DNA damage to apoptosis, is a common cytotoxic agent used for advanced gastric cancer. We investigate the effect of CagA on etoposide-induced apoptosis in gastric cancer cells to elucidate whether CagA play a role in gastric carcinogenesis via impairing DNA damage-dependent apoptosis. AGS cell lines stably expressing CagA isolated from H. pylori 26695 strain were established. In the presence of etoposide, viability of parental AGS cells was decreased in a time-and dose-dependent manner, whereas CagA-expressing AGS cells were less susceptible to etoposide induced cell-killing effect. Suppression of etoposide-induced apoptosis was shown in CagA-expressing but not in parental AGS cells by DNA fragmentation, cell cycle, and annexin-V assays. This inhibitory effect of etoposide-induced apoptosis conferred by CagA was also demonstrated in SCM1 and MKN45 gastric cancer cell lines, with two additional chemotherapeutics, 5-FU and cisplatin. The effect of Akt activation on inhibition of etoposide-induced cytotoxicity by CagA was also evaluated. CagA expression and etoposide administration activate Akt in a dose-dependent manner. Enhancement of etoposide cytotoxicity by a PI-3-kinase inhibitor, LY294002, was evident in parental but was attenuated in CagA-expressing AGS cells. CagA may activate Akt, either in the absence or presence of etoposide, potentially contributing to gastric carcinogenesis associated with H. pylori infection and therapeutic resistance by impairing DNA damage-dependent apoptosis.
ABSTRACT
Helicobacter pylori infection leads to chronic gastritis and increased risk of gastric cancer. The mechanism involves chronic inflammation. We aimed to determine the mechanism by which H. pylori infection causes telomere shortening in inflammatory gastric mucosa. Gastric biopsy specimens were obtained from 20 patients with chronic gastritis or peptic ulcer caused by H. pylori infection. The specimens showed increased NF-κB and superoxide dismutase activities and elevated expressions of PARP-1 and γ-H2AX, all of which returned to normal levels after anti-H. pylori treatment, suggesting that oxidative DNA damage and PARP-1 overexpression might cause telomere shortening. In this report, we adopted DNA end joining assay and showed that H. pylori-infected gastric mucosa had increased alternative NHEJ (non-homologous end joining), implicating that telomere shortening was caused by inflammation-mediated overproduction of reactive oxygen species and PARP-1, leading to telomere shortening.
Subject(s)
DNA End-Joining Repair , Gastric Mucosa/metabolism , Helicobacter pylori/pathogenicity , Inflammation/microbiology , Poly (ADP-Ribose) Polymerase-1/metabolism , Telomere/ultrastructure , Adult , Chronic Disease , DNA/chemistry , DNA Damage , Female , Gastritis/metabolism , Helicobacter Infections/drug therapy , Histones/chemistry , Humans , Hydrogen Peroxide/chemistry , Male , Middle Aged , NF-kappa B/metabolism , Oxidative Stress , Oxygen/chemistry , RNA, Small Interfering/metabolism , Telomere/chemistryABSTRACT
An exploratory phase II biomarker-embedded trial (LPT109747; NCT00526669) designed to determine the association of lapatinib-induced fluoropyrimidine gene changes with efficacy of lapatinib plus capecitabine as first-line treatment for advanced gastric cancer or gastroesophageal junction adenocarcinoma independent of tumor HER2 status. Tumor biopsies obtained before and after 7-day lapatinib (1,250 mg) to analyze changes in gene expression, followed by a 14-day course of capecitabine (1,000 mg/m(2) twice daily, 14/21 days) plus lapatinib 1,250 mg daily. Blood samples were acquired for pharmacokinetic analysis. Primary clinical objectives were response rate (RR) and 5-month progression-free survival (PFS). Secondary objectives were overall survival (OS), PFS, time to response, duration of response, toxicity, and identification of associations between lapatinib pharmacokinetics and biomarker endpoints. Primary biomarker objectives were modulation of 5-FU-pathway genes by lapatinib, effects of germline SNPs on treatment outcome, and trough steady-state plasma lapatinib concentrations. Sixty-eight patients were enrolled; (75% gastric cancer, 25% gastroesophageal junction). Twelve patients (17.9%) had confirmed partial response, 31 (46.3%) had stable disease, and 16 (23.9%) had progressive disease. Median PFS and OS were 3.3 and 6.3 months, respectively. Frequent adverse events included diarrhea (45%), decreased appetite (39%), nausea (36%), and fatigue (36%). Lapatinib induced no changes in gene expression from baseline and no significant associations were found for SNPs analyzed. Elevated baseline HER3 mRNA expression was associated with a higher RR (33% vs. 0%; P = 0.008). Lapatinib plus capecitabine was well tolerated, demonstrating modest antitumor activity in patients with advanced gastric cancer. The association of elevated HER3 and RR warrants further investigation as an important player for HER-targeted regimens in combination with capecitabine. Mol Cancer Ther; 15(9); 2251-8. ©2016 AACR.
Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Stomach Neoplasms/drug therapy , Stomach Neoplasms/pathology , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Biomarkers , Capecitabine/administration & dosage , Disease Progression , ErbB Receptors/genetics , ErbB Receptors/metabolism , Gene Amplification , Humans , Lapatinib , Neoplasm Staging , Polymorphism, Single Nucleotide , Quinazolines/administration & dosage , Receptor, ErbB-2/genetics , Receptor, ErbB-2/metabolism , Signal Transduction , Stomach Neoplasms/metabolism , Stomach Neoplasms/mortality , Treatment OutcomeABSTRACT
The p53 protein is a cell cycle regulator. When the cell cycle progresses, p53 plays an important role in putting a brake on the G1 phase to prevent unwanted errors during cell division. Akt is a downstream kinase of receptor tyrosine kinase. Upon activation, Akt phorphorylates IKK that then phosphorylates IκB and releases NF-κB, leading to transcriptional activation of Dmp1. Dmp1 is a transcriptional activator of Arf. It has been known that oncogene activation stabilizes p53 through transcriptional activation of Arf, which then binds and inhibits Mdm2. In the current study, we show that myc-associated zinc finger protein (MAZ) is a transcriptional repressor of the p53 promoter. Akt phosphorylates MAZ at Thr385, and the phosphorylated MAZ is released from the p53 promoter, leading to transcriptional activation of p53, a new mechanism that contributes to increased p53 protein pool during oncogene activation.
Subject(s)
DNA-Binding Proteins/metabolism , Gene Expression Regulation, Neoplastic , Protein Processing, Post-Translational , Proto-Oncogene Proteins c-akt/physiology , Transcription Factors/metabolism , Tumor Suppressor Protein p53/genetics , Base Sequence , Cell Line, Tumor , Consensus Sequence , DNA-Binding Proteins/chemistry , ErbB Receptors/genetics , ErbB Receptors/metabolism , Gene Knockdown Techniques , Humans , Molecular Sequence Data , Mutation, Missense , Phosphoproteins/metabolism , Phosphorylation , Promoter Regions, Genetic , Protein Binding , Signal Transduction , Transcription Factors/chemistry , Transcription, Genetic , Transcriptional Activation , Tumor Suppressor Protein p53/metabolism , Up-RegulationABSTRACT
The X protein of hepatitis B virus (HBx) has been specifically implicated in the development of hepatocellular carcinoma (HCC). Clinical associations of HBx isoforms with chronic hepatitis and HCC have not been well studied. HBx has two roles in liver cells, namely pro-apoptotic and anti-apoptotic. In this report, we examined the role of Ser31-HBx in HCC and chronic hepatitis. Using the case-control study, we determined risks of chronic hepatitis and HCC conferred by hepatitis B virus (HBV) containing Ser31-HBx that was phosphorylated by Akt. Ser31-HBx isoforms conferred 3.23-fold risk of HCC in male and 3.36-fold risk in female. Ser31 isoforms were associated with 3.12-fold risk of chronic hepatitis and 3.43-fold risk of cirrhosis and also associated with higher HBV viral load and replication efficiency and lower rate of HBe loss. To determine the mechanism, we found that Ser31-HBx constituted an oncogenic circuit with Akt and cooperated with ras to transform NIH3T3 cells in contrast to non-Ser31-HBxs that did not transduce oncogenic signals. Our results give a clue to account for an underlying cause of HBx-mediated hepatocarcinogenesis. It appears that Ser31 phosphorylation of HBx by Akt plays an important role. The current study provides an example of association of HBV genome variations with risks of HCC and chronic hepatitis.
Subject(s)
Carcinoma, Hepatocellular/metabolism , Hepatitis B virus/metabolism , Hepatitis B, Chronic/metabolism , Liver Neoplasms/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Signal Transduction , Trans-Activators/metabolism , Animals , Carcinoma, Hepatocellular/genetics , Carcinoma, Hepatocellular/pathology , Carcinoma, Hepatocellular/virology , HEK293 Cells , Hep G2 Cells , Hepatitis B virus/genetics , Hepatitis B, Chronic/genetics , Hepatitis B, Chronic/pathology , Humans , Liver Neoplasms/genetics , Liver Neoplasms/pathology , Liver Neoplasms/virology , Mice , NIH 3T3 Cells , Protein Isoforms , Proto-Oncogene Proteins c-akt/genetics , Trans-Activators/genetics , Viral Regulatory and Accessory ProteinsABSTRACT
OBJECTIVE: To analyze the efficacy of gemcitabine with or without erlotinib for pancreatic cancer, and to determine the predictive role of epidermal growth factor receptor (EGFR) and KRAS mutations in these patients. METHODS: This was a single-center, randomized, open-label, prospective trial. Eighty-eight chemotherapy-naïve metastatic pancreatic cancer patients were randomized for treatment with gemcitabine or gemcitabine plus erlotinib. EGFR and KRAS mutations were analyzed, respectively. The primary endpoint was the disease control rate. RESULTS: Disease control rate (64% vs. 25%; P < 0.001), progression-free survival (median 3.8 vs. 2.4 months; P < 0.001), and overall survival (median 7.2 vs. 4.4 months; P < 0.001) were better in the gemcitabine plus erlotinib group than in the gemcitabine alone group. In the gemcitabine plus erlotinib group, disease control (85% vs. 33%; P = 0.001), progression-free survival (median 5.9 vs. 2.4 months; P = 0.004), and overall survival (median 8.7 vs. 6.0 months; P = 0.044) were better in patients with EGFR mutations than in those without EGFR mutations. KRAS mutation was not associated with treatment response or survival. CONCLUSIONS: Gemcitabine plus erlotinib is more effective than gemcitabine alone for treating metastatic pancreatic cancer patients, especially those with EGFR mutations. ClinicalTrials.gov number, NCT01608841.
Subject(s)
Antineoplastic Agents/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Deoxycytidine/analogs & derivatives , ErbB Receptors/antagonists & inhibitors , ErbB Receptors/genetics , Erlotinib Hydrochloride/therapeutic use , Mutation , Pancreatic Neoplasms/drug therapy , Protein Kinase Inhibitors/therapeutic use , Adult , Aged , Aged, 80 and over , Antineoplastic Agents/adverse effects , Antineoplastic Combined Chemotherapy Protocols/adverse effects , DNA Mutational Analysis , Deoxycytidine/adverse effects , Deoxycytidine/therapeutic use , Disease-Free Survival , ErbB Receptors/metabolism , Erlotinib Hydrochloride/adverse effects , Female , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Pancreatic Neoplasms/enzymology , Pancreatic Neoplasms/genetics , Pancreatic Neoplasms/mortality , Pancreatic Neoplasms/pathology , Prospective Studies , Protein Kinase Inhibitors/adverse effects , Proto-Oncogene Proteins p21(ras)/genetics , Taiwan , Time Factors , Treatment Outcome , GemcitabineABSTRACT
BACKGROUND AND AIM: Vitamin D3 improves portal hypertension (PH) through the activation of vitamin D receptor (VDR) and calcium-sensing receptor (CaSR) in cirrhotic rats. Propranolol is a non-selective ß-blocker that is recommended for the treatment of PH. The present study aims to investigate the detail systemic and hepatic mechanisms of vitamin D3 and propranolol, alone or in combination, in cirrhotic rats. METHODS: Common bile duct-ligated and thioacetamide cirrhotic rats were treated with vehicle, propranolol (30 mg/kg/day), vitamin D3 (0.5 µg/100 g/day, twice weekly), or propranolol + vitamin D3, separately. RESULTS: Significantly, propranolol and vitamin D3 produced a similar magnitude of reduction in portal venous pressure (PVP) in cirrhotic rats through different mechanisms: whereas propranolol decreased PVP by reducing splanchnic hyperemia and cardiac index, vitamin D3 decreased PVP by decreasing intrahepatic resistance (IHR). However, propranolol + vitamin D3 did not further decrease PVP in cirrhotic rats. Notably, a marked decrease in hepatic VDR and CaSR expressions was noted in cirrhotic human/rat livers compared with non-cirrhotic human/rat livers. In cirrhotic rats, vitamin D3 administration decreasing IHR by inhibiting the renin-angiotensin system, hepatic oxidative stress, inflammation/fibrosis, angiotensin II (ANGII) production, CaSR-mediated ANGII hyperresponsiveness, ANGII-induced hepatic stellate cells contraction, and correcting hepatic endothelial dysfunction through upregulation of hepatic VDR, CaSR, and endothelial nitric oxide synthase expressions. CONCLUSION: Chronic vitamin D3 treatment alone results in comparative portal hypotensive effects as propranolol alone in cirrhotic rats with PH. Taken together, chronic vitamin D3 administration was an ideal alternative strategy to effectively improve PH without unwanted systemic side-effects.
Subject(s)
Cholecalciferol/administration & dosage , Hypertension, Portal/drug therapy , Hypertension, Portal/etiology , Liver Cirrhosis/drug therapy , Liver Cirrhosis/physiopathology , Propranolol/administration & dosage , Propranolol/pharmacology , Vascular Resistance/drug effects , Adrenergic beta-Antagonists , Animals , Cholecalciferol/pharmacology , Disease Models, Animal , Drug Therapy, Combination , Humans , Liver Cirrhosis/complications , Liver Cirrhosis/metabolism , Rats , Receptors, Calcitriol/metabolism , Receptors, Calcium-Sensing/metabolism , Treatment OutcomeABSTRACT
BACKGROUND: The aim of this study was to investigate the impact of hMLH1 polymorphisms on treatment outcomes in patients with oral squamous cell carcinoma (OSCC). METHODS: Genotypings were performed by direct DNA sequencing in peripheral blood leukocytes from 185 male OSCC patients. Patients received primary surgery with or without adjuvant radiotherapy. Two hMLH1 tag single nucleotide polymorphisms (SNPs)-rs1800734 (-93G>A in the promoter) and rs1540354 (in the third intron)-were chosen from the HapMap project. Overall survival (OS) and disease-free survival (DFS) were compared between different genotypes. RESULTS: The hMLH1 rs1800734 and rs1540354 polymorphisms were in weak linkage disequilibrium (r (2) = 0.456). OSCC patients with the rs1800734 AA genotype had a significantly poor prognosis in both OS and DFS. This SNP can also predict the outcomes of OSCC patients with postoperative adjuvant radiotherapy, especially in advanced stage; however, no significant differences in patient outcomes were found for the hMLH1 rs1540354 genotypes. CONCLUSIONS: Our results demonstrate that the hMLH1 -93G>A SNP is found to be associated with patient outcomes in OSCC. This SNP can also predict their treatment outcome of radiotherapy.