Genetic polymorphisms of microsomal epoxide hydrolase and UDP-glucuronosyltransferase (UGT) and its effects on plasma carbamazepine levels and metabolic ratio in persons with epilepsy of South India: A cross-sectional genetic association study.

OBJECTIVES: Carbamazepine (CBZ), an anti-seizure drug, is widely prescribed for the management of focal seizures. At a given therapeutic dose, CBZ exhibits marked interindividual variation in the plasma CBZ levels. The aim wasto study the influence of EPHX1 c.337 T>C and UGT2B7*2 genetic polymorphisms on plasma carbamazepine (CBZ) levels in persons with epilepsy (PWE) from South India. METHODS: 115 PWE belong to South India origin who are on carbamazepine monotherapy were recruited. Genotyping of the two variants weredone using RT-PCR method. PWE who had seizure freedom for one year and their last dose which was not changed for one year duration were included and their plasma levels of CBZ and its active metabolite CBZ 10,11 epoxide were analysed by reverse phase HPLC. RESULTS: In EPHX1 c. 337 (T>C) polymorphism, the PWE carrying CC had lower plasma CBZ levels when compared to CT genotype (2.45 µg/ml vs 3.15 µg/ml. In UGT2B7*2, PWE carrying homozygous mutant TT had higher levels when compared with CT (3.09 µg/ml vs 2.74 µg/ml) genotype but found no statistical significance. Mutant genotype of EPHX1 (CC) had higher metabolic ratio compared to TT genotype (1.33 vs 1.17) but not found to be statistically significant. Mutant genotype of UGT2B7*2 (TT) was found to be having lower metabolic ratio when compared with CC genotype (1.18 vs 1.35; p value =0.08). CONCLUSION: PWE carrying EPHX1 c.337 T>C (rs1051740) and UGT2B7*2 (rs7439366) genetic polymorphisms did not affect the plasma CBZ levels and metabolic ratio of PWE of South Indian origin. However, this finding should be confirmed in a larger sample size which may help in optimization and personalized CBZ therapy in South Indians.

Il-6 and UGT1A1 variations may related to furosemide resistance in heart failure patients.

Furosemide is a diuretic and is used for the treatment of patients with heart failure (HF). It has been found that in some HF patients, the drug does not treat patients efficiently. This condition is named as furosemide resistance. In this study, it is aimed to investigate the relationship between UDP-glucuronosyltransferase 1 (UGT1A1) and interleukine-6 (IL-6) variations with furosemide resistance in HF patients. Sixty HF patients using furosemide (patient group) and 30 healthy individuals (control group) were enrolled in this study. Patients were divided into two subgroups as non-responders (furosemide resistant) group (n = 30) and the responders (non-resistant) group (n = 30) according to the presence of furosemide resistance (n = 30). Variations in the first exon of UGT1A1 and rs1800795 and rs1800796 variations in IL-6 were analyzed by direct sequencing and real-time polymerase chain reaction (RT-PCR), respectively. The effects of newly detected mutations on 3-D protein structure were analyzed by in silico analysis. At the end of the study, 11 variations were detected in UGT1A1, of which nine of them are novel and eight of them cause amino acid change. Also, rs1800795 and rs1800796 variations were detected in all the groups. When patient and control groups were compared with each other, rs1800796 mutation in IL-6 was found statistically high in the patient group (p = 0.027). When the three groups were compared with each other, similarly, rs1800796 mutation in IL-6 was found statistically high in the non-responders group (p = 0.043). When allele distributions were compared between the patient and control groups, the C allele of rs1800795 mutation in IL-6 was found statistically high in the patient group (p = 0.032). When allele distributions were compared between the three groups, 55T-insertion in UGT1A1 was found statistically high in the non-responders group (p = 0.017). According to in silico analysis results, two variations were found deleterious and six variations were detected as probably damaging to protein functions. Our study may contribute to the elucidation of pharmacogenetic features (drug response-gene relationship) and the development of individual-specific treatment strategies in HF patients using furosemide.

Molecular targeting of the UDP-glucuronosyltransferase enzymes in high-eukaryotic translation initiation factor 4E refractory/relapsed acute myeloid leukemia patients: a randomized phase II trial of vismodegib, ribavirin with or without decitabine.

Drug resistance underpins poor outcomes in many malignancies including refractory and relapsed acute myeloid leukemia (R/R AML). Glucuronidation is a common mechanism of drug inactivation impacting many AML therapies, e.g., cytarabine, decitabine, azacytidine and venetoclax. In AML cells, the capacity for glucuronidation arises from increased production of the UDP-glucuronosyltransferase 1A (UGT1A) enzymes. UGT1A elevation was first observed in AML patients who relapsed after response to ribavirin, a drug used to target the eukaryotic translation initiation factor eIF4E, and subsequently in patients who relapsed on cytarabine. UGT1A elevation resulted from increased expression of the sonic-hedgehog transcription factor GLI1. Vismodegib inhibited GLI1, decreased UGT1A levels, reduced glucuronidation of ribavirin and cytarabine, and re-sensitized cells to these drugs. Here, we examined if UGT1A protein levels, and thus glucuronidation activity, were targetable in humans and if this corresponded to clinical response. We conducted a phase II trial using vismodegib with ribavirin, with or without decitabine, in largely heavily pre-treated patients with high-eIF4E AML. Pre-therapy molecular assessment of patients' blasts indicated highly elevated UGT1A levels relative to healthy volunteers. Among patients with partial response, blast response or prolonged stable disease, vismodegib reduced UGT1A levels, which corresponded to effective targeting of eIF4E by ribavirin. In all, our studies are the first to demonstrate that UGT1A protein, and thus glucuronidation, are targetable in humans. These studies pave the way for the development of therapies that impair glucuronidation, one of the most common drug deactivation modalities. Clinicaltrials.gov: NCT02073838.

Efficacy and safety of high doses of irinotecan in patients with metastatic colorectal cancer treated with the FOLFIRI regimen based on the UGT1A1 genotype: A systematic review.

OBJECTIVE: The purpose of this systematic review is to analyze the published data on the efficacy and safety of doses higher than 180 mg/m2 of irinotecan recommended in the drug's summary of product characteristics in  metastatic colorectal cancer patients with genotypes UGT1A1*1/*1 or *1/*28  who are treated with the FOLFIRI regimen. METHOD: A systematic review of the literature was carried out in Medline and  Embase searching for articles published up to December 2021. The methods  used were based on the recommendations of the Preferred Reporting Items for  Systematic Reviews and Meta-Analyses (PRISMA) statement. The criteria  for the inclusion of studies were previously defined based on the two secondary goals addressed in this review: 1) To analyze the magnitude of the differences  in clinical responses and 2) To study the magnitude of the differences in  adverse effects of irinotecan at high doses, as compared to the doses  described in the summary of product characteristics corresponding to the  FOLFIRI regimen in patients with metastatic colorectal cancer with genotypes  UGT1A1*1/* 1 or *1/*28. RESULTS: The search yielded a total of 985 references, of which 13 were selected for analysis. Seven evaluated both efficacy and safety and six  only safety. With regard to the studies that evaluated both efficacy and safety,  six out of seven (85.7%) were in favor of increasing irinotecan dose according  to the objective response rate and progression-free survival. Two of them even  recommended dose increases based on overall survival. Irinotecan safety  studies suggest that doses higher than 180 mg/m2 are tolerated by  most UGT1A1*1/*1 and *1/*28 patients. CONCLUSIONS: The present systematic review shows the advisability of considering adjusting the dose of irinotecan when used as part of the FOLFIRI regimen based on the polymorphisms of the UGT1A1 gene as this may increase the likelihood of an adequate clinical response.

OBJETIVO: El objetivo de la presente revisión sistemática es analizar los datos  publicados sobre la eficacia y seguridad de las dosis superiores a los 180  mg/m2 de irinotecán recomendadas en la ficha técnica en pacientes con cáncer  colorrectal metastásico tratados con el esquema FOLFIRI y con  genotipo UGT1A1*1/*1 y *1/*28.Método: Se realizó una revisión sistemática mediante una búsqueda bibliográfica en Medline y Embase de los artículos publicados hasta diciembre de 2021. Los métodos utilizados se basaron en los  recomendados según Preferred Reporting Items for Systematic Reviews and  Meta-Analyses (PRISMA). Los criterios para la inclusión de los estudios se  definieron previamente en base a los dos objetivos secundarios que aborda  esta revisión: 1) Analizar la magnitud de la diferencia de la respuesta clínica y 2) estudiar la magnitud de la diferencia de los efectos  dversos a irinotecán a dosis altas, en comparación con las dosis descritas en la ficha técnica para el esquema FOLFIRI en pacientes con cáncer colorrectal metastásico con el genotipo UGT1A1*1/*1 o *1/*28. RESULTADOS: La estrategia de búsqueda reportó un total de 98 referencias, de  las que 13 fueron seleccionadas para el análisis, 7 (53,8%)  evaluando tanto  eficacia como seguridad y 6 (46,2%) únicamente seguridad. En relación con  los estudios que evaluaron eficacia y seguridad, 6 (85,7%) se mostraron  favorables al aumento de dosis en términos de tasa de respuesta objetiva y  supervivencia libre de progresión e, incluso, en 2 de ellos en supervivencia  global. Los estudios que evaluaron seguridad apuntan a que dosis de irinotecán  superiores a 180 mg/m2 son toleradas por la mayor parte de los  pacientes UGT1A1*1/*1 y *1/*28. CONCLUSIONES: La presente revisión sistemática muestra la conveniencia de  valorar el ajuste de dosis de irinotecán dentro del esquema FOLFIRI en función  de los polimorfismos del gen UGT1A1, con un potencial aumento de  las probabilidades de una adecuada respuesta clínica.

Eficacia y seguridad de dosis altas de irinotecán en pacientes con cáncer colorrectal metastásico tratados con el esquema FOLFIRI en función delgenotipo de UGT1A1: Revisión sistemática / Efficacy and safety of high doses of irinotecan in patients with metastatic colorectal cancer treated with the FOLFIRI regimen based on the UGT1A1 genotype: A systematic review

Objetivo: El objetivo de la presente revisión sistemática es analizar losdatos publicados sobre la eficacia y seguridad de las dosis superioresa los 180 mg/m2 de irinotecán recomendadas en la ficha técnica enpacientes con cáncer colorrectal metastásico tratados con el esquemaFOLFIRI y con genotipo UGT1A1*1/*1 y *1/*28.Método: Se realizó una revisión sistemática mediante una búsquedabibliográfica en Medline y Embase de los artículos publicados hastadiciembre de 2021. Los métodos utilizados se basaron en los recomendados según Preferred Reporting Items for Systematic Reviews and MetaAnalyses (PRISMA). Los criterios para la inclusión de los estudios se definieron previamente en base a los dos objetivos secundarios que abordaesta revisión: 1) Analizar la magnitud de la diferencia de la respuestaclínica y 2) estudiar la magnitud de la diferencia de los efectos adversosa irinotecán a dosis altas, en comparación con las dosis descritas en laficha técnica para el esquema FOLFIRI en pacientes con cáncer colorrectal metastásico con el genotipo UGT1A1*1/*1 o *1/*28.Resultados: La estrategia de búsqueda reportó un total de 98 referencias, de las que 13 fueron seleccionadas para el análisis, 7 (53,8%) evaluando tanto eficacia como seguridad y 6 (46,2%) únicamente seguridad. En relación con los estudios que evaluaron eficacia y seguridad,6 (85,7%) se mostraron favorables al aumento de dosis en términos detasa de respuesta objetiva y supervivencia libre de progresión e, incluso,en 2 de ellos en supervivencia global. Los estudios que evaluaron seguridad apuntan a que dosis de irinotecán superiores a 180 mg/m2 sontoleradas por la mayor parte de los pacientes UGT1A1*1/*1 y *1/*28. (AU)

Objective: The purpose of this systematic review is to analyze the published data on the efficacy and safety of doses higher than 180 mg/m2 ofirinotecan recommended in the drug’s summary of product characteristicsin metastatic colorectal cancer patients with genotypes UGT1A1*1/*1 or*1/*28 who are treated with the FOLFIRI regimen.Method: A systematic review of the literature was carried out in Medlineand Embase searching for articles published up to December 2021. Themethods used were based on the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.The criteria for the inclusion of studies were previously defined based on thetwo secondary goals addressed in this review: 1) To analyze the magnitudeof the differences in clinical responses and 2) To study the magnitude of thedifferences in adverse effects of irinotecan at high doses, as compared tothe doses described in the summary of product characteristics corresponding to the FOLFIRI regimen in patients with metastatic colorectal cancerwith genotypes UGT1A1*1/* 1 or *1/*28.Results: The search yielded a total of 985 references, of which 13 wereselected for analysis. Seven evaluated both efficacy and safety and six only safety. With regard to the studies that evaluated both efficacy andsafety, six out of seven (85.7%) were in favor of increasing irinotecan doseaccording to the objective response rate and progression-free survival.Two of them even recommended dose increases based on overall survival.Irinotecan safety studies suggest that doses higher than 180 mg/m2 aretolerated by most UGT1A1*1/*1 and *1/*28 patients. (AU)

Delayed Diagnosis of Clostridium difficile Colitis in a 48-Year-Old Woman with a Homozygous Mutation of the UGT1A1 Gene While on Chemotherapy for Colorectal Carcinoma.

BACKGROUND There are many causes of chronic colitis and diarrhea, including the effects of chemotherapy. Mutations in the UGT1A1 gene can be associated with increased toxicity from irinotecan-based chemotherapy. This report is of a case of delayed diagnosis of Clostridium difficile (C. difficile) colitis in a 48-year-old woman with a homozygous mutation of the UGT1A1 gene treated with chemotherapy for colorectal carcinoma. CASE REPORT A 48-year-old woman with a low-differentiated colonic adenocarcinoma was treated after surgery with irinotecan, 5 fluorouracil, and panitumumab and had a history of chronic and severe diarrhea. Genetic testing identified a mutation in the UGT1A1 gene associated with increased toxicity to irinotecan, and the EIA tests performed for evaluation of C. difficile toxins A and B showed repeatedly negative results. Replacement of irinotecan with oxaliplatin did not have significant therapeutic results, but these were achieved by the administration of active antibiotics against C. difficile (metronidazole, vancomycin, and fidaxomicin). CONCLUSIONS This report has shown that in complex cases where patients are treated with chemotherapy and have increased susceptibility to drug toxicity, chronic diarrhea may still have an infectious cause. Only when the diagnosis is correctly made can the patient be appropriately treated.

Sustained reduction of hyperbilirubinemia in Gunn rats after adeno-associated virus-mediated gene transfer of bilirubin UDP-glucuronosyltransferase isozyme 1A1 to skeletal muscle.

Crigler-Najjar syndrome is an autosomal recessive disorder with severe unconjugated hyperbilirubinemia due to deficiency of bilirubin UDP-glucuronosyltransferase isozyme 1A1 (UGT1A1) encoded by the UGT1A1 gene. Current therapy relies on phototherapy to prevent life-threatening elevations of serum bilirubin levels, but liver transplantation is the only permanent treatment. Muscle-directed gene therapy has several advantages, including easy and safe access through simple intramuscular injections, and has been investigated in human clinical trials. In this study, we have investigated the efficacy of adeno-associated viral (AAV) vector-mediated muscle-directed gene therapy in the preclinical animal model of Crigler-Najjar syndrome, that is the Gunn rat. Serotype 1 AAV vector expressing rat UGT1A1 under the control of muscle-specific creatine kinase promoter was injected at a dose of 3×10(12) genome copies/kg into the muscles of Gunn rats and resulted in expression of UGT1A1 protein and functionally active enzyme in injected muscles. AAV-injected Gunn rats showed an approximately 50% reduction in serum bilirubin levels as compared with saline-treated controls, and this reduction was sustained for at least 1 year postinjection. Increased excretion of alkali-labile metabolites of bilirubin in bile and urine was detected in AAV-injected animals. High-performance liquid chromatography analysis of bile from AAV-injected Gunn rats showed a metabolite with retention time close to that of bilirubin diglucuronide. Taken together, these data show that clinically relevant and sustained reduction of serum bilirubin levels can be achieved by simple and safe intramuscular injections in Gunn rats. AAV-mediated muscle directed gene therapy has potential for the treatment of patients with Crigler-Najjar syndrome type 1.

Amelioration of osteoarthritis by intra-articular hyaluronan synthase 2 gene therapy.

Osteoarthritis (OA) is a chronic, degenerative disorder of multifactorial aetiology, characterized by loss of articular cartilage and periarticular bone remodelling. Goals of managing OA include controlling pain, maintaining and improving function and health-related quality of life, and limiting functional impairment. Although several managements had been proved to ameliorate the symptoms of osteoarthritis, no methods could cure it thoroughly. High-molecular-weight hyaluronan (HMW-HA) is a major component of synovial joint fluids which physically acts as a viscous lubricant for slow joint movements and as an elastic shock absorber during rapid movements. It also has a variety of biologic effects in vivo, such as inhibiting the release of inflammatory factors and suppressing the degradation of cartilage matrix. Intra-articular injection of synthetic HMW-HA has been used as viscosupplement for knee OA and its therapeutic efficacy has been verified. However, repeated injections of HMW-HA which is needed to control symptoms increase the probability of infection and sometimes there will have acute joint pain with effusion, which requires aspiration to exclude sepsis. In order to overcome the disadvantages of repeated injections of HMW-HA, novel strategies should be developed. As HMW-HA is synthesized by hyaluronan synthase-2 (HAS2), we postulate that HAS2 gene could be delivered into intra-articular cells by methods of gene therapy to achieve long-lasting synthesis of HMW-HA. In our opinion, this strategy seems to hold interesting future prospects for the treatment of OA.

Successful treatment of UGT1A1 deficiency in a rat model of Crigler-Najjar disease by intravenous administration of a liver-specific lentiviral vector.

Treatment of congenital and acquired liver disease is one of the main issues in the field of gene therapy. Self-inactivating lentiviral vectors have several potential advantages over alternative systems. We have constructed a self-inactivating lentiviral vector (LV-ALBUGT) that expresses the human bilirubin UDP-glucuronosyltransferase (UGT1A1) from a liver-specific promoter. UGT1A1 is involved in the clearance of heme metabolites in the liver. This enzyme is deficient in Crigler-Najjar disease, a recessive inherited disorder in humans characterized by chronic severe jaundice, i.e., high plasma bilirubin levels. Gunn rats suffer from the same defect and are used as an animal model of this disease. We have treated juvenile Gunn rats by single intravenous injection with the LV-ALBUGT vector. Over 1 year after treatment with the highest dose (5 x 10(8) transducing units), we observed a stable reduction of bilirubin levels to near normal levels and normal secretion of bilirubin conjugates in the bile, in contrast to untreated animals. In situ hybridization showed expression of the therapeutic gene in more than 30% of liver parenchymal cells. Thus, we demonstrate stable and complete clinical remission of a congenital metabolic liver disease in an animal model, after systemic administration of a therapeutic lentiviral vector.

Therapeutic lentivirus-mediated neonatal in vivo gene therapy in hyperbilirubinemic Gunn rats.

Crigler-Najjar type 1 disease (CN-1) is a genetic disorder characterized by high levels of unconjugated bilirubin due to the absence of hepatic UDPglucuronosyltransferase (UGT1) activity. Here we show that in vivo neonatal hepatocyte transduction with a lentiviral vector expressing the defective enzyme resulted in long-term correction in Gunn rats, a model of CN-1. Lentiviral vectors harboring the human UGT1 cDNA (approved symbol UGT1A1) under the control of a liver-specific transthyretin promoter were produced. Two-day-old Gunn rats were injected with 50 microl of vector. Bilirubinemia was monitored at 6 weeks and monthly thereafter. At 6 weeks, bilirubinemia was completely normalized in treated animals, whereas it remained around 100 microM in control rats. The level of correction remained stable for up to 42 weeks. Large amounts of bilirubin conjugates were present in the bile of corrected animals. PCR and Western blots confirmed the presence and expression of UGT1 in liver. The estimated proportion of transduced hepatocytes was 40% and transduced cells were not detected in extrahepatic tissues except bone marrow in some animals. This work represents the first demonstration of a complete and permanent correction of hyperbilirubinemia in Gunn rats using lentiviral vectors.

Single hepatic venous injection of liver-specific naked plasmid vector expressing human UGT1A1 leads to long-term correction of hyperbilirubinemia and prevention of chronic bilirubin toxicity in Gunn rats.

Previously, we have demonstrated that hepatic venous injection of pcDNA3hUGT1A1 expressing human bilirubin glucuronosyl transferase 1A1 (hUGT1A1) under the control of the cytomegalovirus promoter results in excretion of bilirubin glucuronides in bile and significant decrease in serum bilirubin for at least 2 weeks in the Gunn rat, an animal model of Crigler-Najjar syndrome type I. In this study we compared repeat delivery of pcDNA3hUGT1A1 with single injection of pBShUGT1A1 expressing hUGT1A1 under liver-specific regulatory control, for treatment of hyperbilirubinemia in the Gunn rat. Although repeat injections of pcDNA3hUGT1A1 consistently reduced serum bilirubin levels, the effect did not exceed 2 weeks; hUGT1A1 was detectable in livers only for 2 weeks, despite the presence of vector and transcript for at least 1 month. In contrast, injection of pBShUGT1A1 resulted in persistence of vector, transcript, and recombinant protein and sustained correction of hyperbilirubinemia for at least 8 months; furthermore, renal tubular damage, the principal manifestation of chronic bilirubin toxicity in the Gunn rat, was prevented. Sera from animals treated with pBShUGT1A1 consistently contained anti-hUGT1A1 antibodies, but a significant increase in the number of hepatic CD4(+) and CD8(+) cells was seen only in the pcDNA3hUGT1A1 group; thus liver-specific expression of hUGT1A1 may attenuate immune response. Our results provide further evidence of the feasibility of long-term correction of hepatic enzyme deficiencies with plasmid vectors optimized for expression in the liver.

Long-term reduction of serum bilirubin levels in Gunn rats by retroviral gene transfer in vivo.

Conjugation with glucuronic acid, mediated by bilirubin-uridinediphosphoglucuronate glucuronosyltransferase (bilirubin-UGT), is essential for efficient biliary excretion of bilirubin. Inherited absence of this enzyme activity results in the potentially lethal Crigler-Najjar syndrome type I in humans and lifelong hyperbilirubinemia in Gunn rats. To develop a gene therapy for bilirubin-UGT deficiency, we constructed a high-titer replication-deficient amphotropic recombinant retrovirus (MFG-S hB-UGT1) capable of transferring the gene encoding bilirubin-UGT1, the principal bilirubin-UGT isoform in human liver. To stimulate hepatocyte proliferation, Gunn rats were subjected to 66% hepatectomy. After 24 hours, the portal vein, the hepatic artery, and the inferior vena cava above and below the hepatic vein were clamped, and the portal vein and the isolated segment of the vena cava were cannulated. The liver was perfused with the MFG-S hB-UGT1 preparation through the portal vein at 5 ml/min for 10 minutes, then circulation was restored. Control rat livers were perfused with a recombinant retrovirus expressing Escherichia coli beta-galactosidase. In MFG-S hB-UGT1-perfused rats, but not in controls, expression of human bilirubin-UGT1 was shown by immunotransblotting, bilirubin-UGT assay of liver homogenates, and biliary excretion of bilirubin diglucuronide and monoglucuronide. Mean serum bilirubin levels decreased by 20% to 25% in 3 weeks and remained at that level throughout the study period (18 months). This is the first report of long-term amelioration of inherited jaundice by retrovirus-directed gene therapy in an animal model for Crigler-Najjar syndrome.

The application of immobilized enzymes in an artificial liver support system.

A novel method of extracorporeal support for fulminant liver failure is reported whereby the most important detoxification processes of the liver are reproduced in an enzyme reactor. Most of the endogenous toxins involved in hepatic coma can be deactivated directly by conjugation with a hydrophilic residue such as glucuronic acid or glutathione, or by the neutralization of active groups through structural modification by methyl transfer. The enzymes responsible for these processes have been isolated and purified from rabbit liver, and covalently bound onto a hemocompatible form of agarose matrix. This system has been shown to be capable of catalyzing the desired reactions with endogenous toxins such as phenols and mercaptans in vitro, and phenols in rabbits in vivo.