Cytochrome P450 3A5 polymorphism affects the metabolism of sorafenib and its toxicity for hepatocellular carcinoma cells in vitro

Objective Cytochrome P450 3A5 ( CYP3A5) is a highly polymorphic gene and the encoded protein variants differ in catalytic activity, leading to inter-individual variation in metabolic ability. The aim of the current study was to investigate the effects of seven allelic variants on the ability of CYP3A5 to metabolize sorafenib in vitro and further explore the impacts of CYP3A5 polymorphism on the proliferation and apoptosis of hepatocellular carcinoma cell line (HepG2) induced by sorafenib. Methods Wild-type and variant CYP3A5 enzymes were expressed in Spodoptera frugiperda insect cells using a baculovirus dual-expression system, and protein expression was checked by western blot. The enzymes were incubated with sorafenib at 37°C for 30 min, and formation of the major metabolite sorafenib N-oxide was assayed using ultra-performance liquid chromatography and tandem mass spectrometry. Intrinsic clearance values (V max/ K m) were calculated for each enzyme. Additionally, recombinant HepG2 cells transfecting with CYP3A5 variants were used to investigate the effects of sorafenib on the proliferation of HepG2 cells. Results Intrinsic clearance of the six variants CYP3A5*2, CYP3A5*3A, CYP3A5*3C, CYP3A5*4, CYP3A5*5, and CYP3A5*7 was 26.41–71.04% of the wild-type ( CYP3A5*1) value. In contrast, the clearance value of the variant CYP3A5*6 was significantly higher (174.74%). Additionally, the decreased ATP levels and cell viability and the increased cell apoptosis in HepG2 cells transfected with CYP3A5*2, CYP3A5*3A, CYP3A5*3C, CYP3A5*4, CYP3A5*5, and CYP3A5*7 were observed, whereas, the increased ATP levels and cell viability and the reduced cell apoptosis in HepG2 cells transfected with CYP3A5*6 were also investigated when compared to CYP3A5*1. Conclusion Our results suggest that CYP3A5 polymorphism influences sorafenib metabolism and pharmacotherapeutic effect in hepatic carcinomas . These data may help explain differential response to drug therapy for hepatocellular carcinoma, and they support the need for individualized treatment.

The Impact of Cytochrome P450 3A5 Genotype on Early Tacrolimus Metabolism and Clinical Outcomes in Lung Transplant Recipients

Background Tacrolimus (Tac) is the cornerstone of immunosuppressant therapy after lung transplantation (LTx). It shows great inter-individual variability in pharmacokinetics, which could partly be explained by pharmacogenetic factors. Objective We aim to investigate the effect of cytochrome P450 3A5 (CYP3A5) (rs776746) genotypes on early post-operative Tac metabolism and clinical outcomes in LTx recipients. Methods 90 recipients who underwent LTx from 2017 to 2019 at our institution were enrolled in the study. The effect of CYP3A5 genotype on Tac concentration, dose, dose adjusted concentration (C/D) and interaction with azole antifungals were assessed during week 1–4 after transplantation. Associations between CYP3A5 genotype and the incidence of acute kidney injury (AKI), length of hospital stay and mortality were analyzed. Results CYP3A5*1 carriers had lower C/D than CYP3A5*3/*3 group at all time points (p < 0.05). To reach comparable blood concentrations, CYP3A5*1 carriers required higher doses compared with CYP3A5*3/*3 group (p < 0.05). Use of azole antifungals did not blunt the effect of CYP3A5 genotypes on Tac metabolism. Logistic regression showed Tac concentration at week 1, not CYP3A5 genotype, was associated with the incidence of AKI. No statistically significant difference was found between CYP3A5 genotypes and the length of hospital stay (48 (37–68) vs 46(32–57) days, p = 0.264). Kaplan–Meier analysis showed no statistically significant difference between 30-day or 1-year mortality and CYP3A5 genotype. Conclusion CYP3A5 genotype could affect Tac metabolism early after LTx. However, it has no influence on the incidence of AKI, length of hospital stay and mortality.

Study of CYP3A5 genetic polymorphism in Vietnamese Kinh ethnic group

Cytochrome P450 3A5 (CYP) belongs to the CYP3A cluster, which encode for several enzymes involved in metabolism of various drugs, endogenous substrates as well as exogenous compounds. Among the four genes of CY3A cluster, CYP3A5 plays an important role in pharmacogenetics since this enzyme metabolizes over 30% of the clinically prescribed drugs. The inter-individual variability in clearance of CYP3A substrates mainly depends on the genetic factors. In the present study, after collecting peripheral bloods samples from 100 unrelated healthy Kinh ethnic group in Vietnam, Sanger sequencing was used in order to determine the CYP3A5 variants responsible for enzyme activity alteration (*3, *6, *8 and *9). It was shown that CYP3A5*3 is the most prevalent variant with 67.5%, in which a haft of individuals carrying *3 were homozygous for this allele. In contrast, the variants *6, *8 and *9 were not found the study subjects. The data observed in current study would support dosing of drugs that metabolized by CYP3A5 and thereby increase treatment outcome.