This article has not been copyedited and formatted. The final version may differ from this version. Abstract Lapatinib, an oral tyrosine kinase inhibitor used for breast cancer, has been reported to cause idiosyncratic hepatotoxicity. Recently, it has been found that lapatinib forms a metabolite-inhibitor complex (MIC) with CYP3A4 via the formation of an alkylnitroso intermediate. As CYP3A5 is ...

The current study was a follow-up to an in vivo study in which atazanavir oral clearance was shown to be dependent on genetically determined CYP3A5 expression status, but only in non-African Americans. The aim of this study was to identify atazanavir metabolites generated by CYP3A5 and to evaluate this metabolite pattern in the African-American versus non-African-American CYP3A5 expressors from...

The members of the cytochrome P450 (CYP) 3A subfamily play an important role in the metabolism of more than 50% of the drugs metabolized by CYPs. Among the CYP3A members, CYP3A5 is known to exhibit polymorphic expression within the human liver. We hypothesized that a single nucleotide polymorphism (SNP) in the 5'-regulatory region of the CYP3A5 gene might be the cause of CYP3A5 polymorphic expr...

CYP3A5 is a cytochrome P450 protein that functions in the liver metabolism of many carcinogens and cancer drugs. However, it has not been thought to directly affect cancer progression. In this study, we challenge this perspective by demonstrating that CYP3A5 is downregulated in many hepatocellular carcinomas (HCC), where it has an important role as a tumor suppressor that antagonizes the malign...

Testosterone is needed for the growth and development of the prostate. Androgen deprivation therapy is used for the treatment of prostate cancer. CYP3A5 is a human drug-metabolizing cytochrome P450 enzyme that metabolizes testosterone to the inactive 6beta-hydroxylated metabolite. We identified CYP3A5 as a novel androgen-regulated gene in human prostate by GeneChip analysis of human prostate ti...

CYP3A5 is the major CYP3A form in the human lung, and it is inducible by dexamethasone in the human A549 lung adenocarcinoma cell line. In the present study, we characterized the nature and mechanism of this induction process. The induction of CYP3A5 mRNA was assessed by quantitative reverse transcriptase-polymerase chain reaction in A549 cells. About 4-fold induction was detected by nanomolar ...

This study was conducted to evaluate the effects of the CYP2D6 and CYP3A5 genotypes on the steady-state plasma levels of risperidone (RIS), 9-hydroxyrisperidone (9-OH-RIS), and the active moiety (RIS plus 9-OH-RIS) in Korean schizophrenic patients. Sixty-four Korean schizophrenic patients were enrolled. CYP2D6 and CYP3A5 genotypes were determined, and the plasma levels of RIS and 9-OH-RIS were ...

To the Editor: Therapeutic drug monitoring of immunosuppressants is well established as an aid to optimizing patient management after allograft transplantation. Most laboratories measure cyclosporin and tacrolimus by immunoassays. However, measured values may be affected by the presence of circulating metabolites because of the limited specificity of the antibodies used in these assays. Cyclosp...

The antipsychotic drug quetiapine is extensively metabolized by CYP3A4, but little is known about the possible influence of the polymorphic enzyme CYP3A5. This in vitro study investigated the relative importance of CYP3A4 and CYP3A5 in the metabolism of quetiapine and compared the metabolic pattern by the two enzymes, in the presence or absence of cytochrome b5. Intrinsic clearance (CLint) of q...

The antipsychotic drug quetiapine is extensively metabolized by CYP3A4, but little is known about the possible influence of the polymorphic enzyme CYP3A5. This in vitro study investigated the relative importance of CYP3A4 and CYP3A5 in the metabolism of quetiapine and compared the metabolic pattern by the two enzymes, in the presence or absence of cytochrome b5. Intrinsic clearance (CLint) of q...