Genetic polymorphisms of the CYP3A4, CYP3A5, CYP3A7 and CYP1A2 among the Jordanian population

Genetic association in CYP3A4 and CYP3A5 genes elevate the risk of prostate cancer

BACKGROUND

CYP3A4 and CYP3A5 are biologically potential genes responsible for prostate cancer.

AIM

We aimed to analyse the expression and association of CYP3A4 and CYP3A5 genes in prostate cancer.

SUBJECTS AND METHODS

Web-based bioinformatics tools were used to assess the association of CYP3A4 and CYP3A5 genes with prostate cancer risks. A case-control study of 210 prostate cancer cases and 207 controls was also approved to determine the allelic variants of the CYP3A4 gene- rs2740574 (CYP3A4*1B) and the variant of CYP3A5 gene-rs776746 (CYP3A5*3) using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP). The risk of prostate cancer was estimated as odds ratio (OR) and 95% confidence interval (CI) using unrestricted logistic regression models.

RESULTS

Our in silico data confirmed that both CYP3A4 and CYP3A5 genes are significantly associated with higher prostate cancer risks. In the case of CYP3A4*1B polymorphism, the heterozygote (*1 A/*1B), mutant (*1B/*1B), and combined heterozygote plus mutant (*1A/*1B+*1B/*1B) genotypes showed 3.52-fold, 3.90-fold, and 3.67-fold increased risk of prostate cancer, respectively. In the case of CYP3A5*3 polymorphism, the heterozygote (*1/*3), mutant (*3/*3), and combined (*1/*3+*3/*3) genotypes were found to be significantly associated with 5.11-, 5.49-, and 5.28-fold greater risk of prostate cancer, respectively.

CONCLUSION

Our results indicate that CYP3A4*1B and CYP3A5*3 are significantly associated with increased prostate cancer risk.KEY MESSAGESBioinformatics tools were used and concluded that the CYP3A4 and CYP3A5 genes were significantly associated with the development and progression of prostate cancer.CYP3A4 and CYP3A5 polymorphisms were significantly associated with an increased risk of prostate cancer.Polymerase Chain Reaction (PCR)-Restriction Fragment Length Polymorphism (RFLP) was used to estimate polymorphisms of prostate cancer progression in the Bangladeshi population.

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.

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.

Allele and genotype frequencies of CYP3A4, CYP3A5, CYP3A7, and GSTP1 gene polymorphisms among mainland Tibetan, Mongolian, Uyghur, and Han Chinese populations

Over 50% prescribed drugs are metabolised by cytochrome P450 3A (CYP3A) and glutathione S-transferase pi (GSTP1) adds a glutathione to the oxidative products by CYP3A, which increases the hydrophilic property of metabolites and facilitates the excretion. Single nucleotide polymorphisms (SNPs) of CYP3A and GSTP1 show a diverse allele and genotype frequencies distribution among the world populations. The present study aimed to investigate the genotype and allele frequency distribution patterns of CYP3A4, CYP3A5, CYP3A7 and GSTP1 polymorphisms among healthy participants in mainland Tibetan, Mongolian, Uyghur, and Han Chinese populations. Blood samples were collected from 842 unrelated healthy subjects (323 Tibetan, 134 Mongolian, 162 Uyghur, and 223 Han) for genotyping analysis. Variant allele frequencies of CYP3A4 rs2242480, CYP3A5 rs776746, CYP3A7 rs2257401, and GSTP1 Ile105Val were observed in Han (0.253, 0.686, 0.312 and 0.188), Tibetan (0.186, 0.819, 0.192 and 0.173), Mongolian (0.198, 0.784, 0.228 and 0.235) and Uyghur (0.179, 0.858, 0.182 and 0.250) respectively. The allele frequency of CYP3A7*1C in Uyghur (0.019) was higher than that in Tibetan (0.002, p < 0.01). There was a strong linkage disequilibrium between CYP3A4 rs2242480, CYP3A5 rs776746, and CYP3A7 rs2257401 among the four ethnic groups. The results might be useful for the precise medication in the Chinese populations.

Genetic variability of CYP2D6, CYP3A4 and CYP3A5 among the Egyptian population

Aim: This study investigated major allelic variants of CYP2D6, CYP3A4 and CYP3A5 in Egyptians, an Arabic population for which there is little information regarding these important pharmacogenes. Patients & methods: CYP2D6*2, *4, *5, *10, *41 and gene copy number variation, as well as CYP3A4*22 and CYP3A5*3 were determined with commercially available TaqMan assays in 145 healthy study participants. Results: The CYP2D6 alleles identified suggest that the prevalence of poor metabolizers is low as none were found among the 145 subjects investigated. The frequency for CYP3A5 nonexpressers was 74.5% and the CYP3A4*22 allele frequency was low at 2.0%. Conclusion: These preliminary findings indicate that pharmacogene variation in Egyptians is different from those of other Middle Eastern/Arabic populations and warrants further investigation.

Neonatal cytochrome P450 CYP3A7: A comprehensive review of its role in development, disease, and xenobiotic metabolism

The human cytochrome P450 CYP3A7, once thought to be an enzyme exclusive to fetal livers, has more recently been identified in neonates and developing infants as old as 24 months post-gestational age. CYP3A7 has been demonstrated to metabolize two endogenous compounds that are known to be important in the growth and development of the fetus and neonate, namely dehydroepiandrosterone sulfate (DHEA-S) and all-trans retinoic acid (atRA). In addition, it is also known to metabolize a variety of drugs and xenobiotics, albeit generally to a lesser extent relative to CYP3A4/5. CYP3A7 is an important component in the development and protection of the fetal liver and additionally plays a role in certain disease states, such as cancer and adrenal hyperplasia. Ultimately, a full understanding of the expression, regulation, and metabolic properties of CYP3A7 is needed to provide neonates with appropriate individualized pharmacotherapy. This article summarizes the current state of knowledge of CYP3A7, including its discovery, distribution, alleles, RNA splicing, expression and regulation, metabolic properties, substrates, and inhibitors.

Genetic polymorphism analysis of the drug-metabolizing enzyme CYP1A2 in a Uyghur Chinese population: a pilot study

1. CYP1A2 is a highly polymorphic gene and CYP1A2 enzyme results in broad inter-individual variability in response to certain pharmacotherapies, while little is known about the genetic variation of CYP1A2 in Uyghur Chinese population. The aim of the present study was to screen Uyghur volunteers for CYP1A2 genetic polymorphisms. 2. We used DNA sequencing to investigate promoter, exons, introns, and 3' UTR of the CYP1A2 gene in 96 unrelated healthy Uyghur individuals. We also used SIFT (Sorting Intolerant From Tolerant) and PolyPhen-2 (Polymorphism Phenotyping v2) to predict the protein function of the novel non-synonymous mutation in CYP1A2 coding regions. 3. We identified 20 different CYP1A2 polymorphisms in the Uyghur Chinese population, including two novel variants (119A > G and 2410G > A). Variant 119A > G was predicted to be probably damaging on protein function by PolyPhen-2, by contrast, 2410G > A was identified as benign. The allele frequencies of CYP1A2*1A, *1B, *1F, *1G, *1J, *1M, *4, and *9 were 23.4%, 53.1%, 3.7%, 2.6%, 2.6%, 13.5%, 0.5%, and 0.5%, respectively. The frequency of *1F, a putative high inducibility allele, was higher in our sample population compared with that in the Caucasian population (p < 0.05). The most common genotype combinations were *1A/*1B (46.9%) and *1B/*1M (27.1%). 4. Our results provide basic information on CYP1A2 polymorphisms in Uyghur individuals and suggest that the enzymatic activities of CYP1A2 may differ among the diverse ethnic populations of the world.

Genetic polymorphisms in promoter and intronic regions of CYP1A2 gene in Roma and Hungarian population samples

The purpose of this study was to determine the interethnic differences of four CYP1A2 drug metabolizing enzyme variants. A total of 404 Roma and 396 Hungarian healthy subjects were genotyped for -163C>A, -729C>T, -2467delT and -3860G>A variants of CYP1A2 by RT-PCR and PCR-RFLP technique. The -3860A and -729T allele were not detectable in Roma samples, while in Hungarian samples were present with 2.02% and 0.25% prevalence, respectively. There was a 1.5-fold difference in presence of homozygous -163AA genotype between Hungarian and Roma samples (49.5% vs. 31.9%, p<0.001). The -163A allele frequency was 68.6% in Hungarians and 56.9% in Romas (p=0.025). The -2467delT allele frequency was 6.81% in Roma group and 5.81% in Hungarians. The most frequent allelic constellation was -3860G/-2467T/-729C/-163A in both populations. In conclusion, Hungarians have markedly elevated chance for rapid metabolism of CYP1A2 substrates, intensified procarcinogen activation and increased risk for cancers.

Relationship between genotypes Sult1a2 and Cyp2d6 and tamoxifen metabolism in breast cancer patients

Tamoxifen is a pro-drug widely used in breast cancer patients to prevent tumor recurrence. Prior work has revealed a role of cytochrome and sulfotransferase enzymes in tamoxifen metabolism. In this descriptive study, correlations were examined between concentrations of tamoxifen metabolites and genotypes for CYP2D6, CYP3A4, CYP3A5, SULT1A1, SULT1A2 and SULT1E1 in 135 patients with estrogen receptor-positive breast cancer. Patients were genotyped using the Roche-AmpliChip® CYP450 Test, and Real-Time and conventional PCR-RFLP. Plasma tamoxifen, 4-hydroxy-tamoxifen, N-desmethyl-tamoxifen, endoxifen and tamoxifen-N-oxide were isolated and quantified using a high-pressure liquid chromatography-tandem mass spectrometry system. Significantly higher endoxifen levels were detected in patients with the wt/wt CYP2D6 compared to the v/v CYP2D6 genotype (p<0.001). No differences were detected in the remaining tamoxifen metabolites among CYP2D6 genotypes. Patients featuring the SULT1A2*2 and SULT1A2*3 alleles showed significantly higher plasma levels of 4-hydroxy-tamoxifen and endoxifen (p = 0.025 and p = 0.006, respectively), as likely substrates of the SULT1A2 enzyme. Our observations indicate that besides the CYP2D6 genotype leading to tamoxifen conversion to potent hydroxylated metabolites in a manner consistent with a gene-dose effect, SULT1A2 also seems to play a role in maintaining optimal levels of both 4-hydroxy-tamoxifen and endoxifen.