Gene Summary

Gene:CYP3A4; cytochrome P450 family 3 subfamily A member 4
Aliases: HLP, CP33, CP34, CYP3A, NF-25, CYP3A3, P450C3, CYPIIIA3, CYPIIIA4, P450PCN1
Summary:This gene encodes a member of the cytochrome P450 superfamily of enzymes. The cytochrome P450 proteins are monooxygenases that catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids and other lipids. This protein localizes to the endoplasmic reticulum and its expression is induced by glucocorticoids and some pharmacological agents. This enzyme is involved in the metabolism of approximately half the drugs in use today, including acetaminophen, codeine, cyclosporin A, diazepam and erythromycin. The enzyme also metabolizes some steroids and carcinogens. This gene is part of a cluster of cytochrome P450 genes on chromosome 7q21.1. Previously another CYP3A gene, CYP3A3, was thought to exist; however, it is now thought that this sequence represents a transcript variant of CYP3A4. Alternatively spliced transcript variants encoding different isoforms have been identified. [provided by RefSeq, Feb 2011]
Databases:OMIM, HGNC, Ensembl, GeneCard, Gene
Protein:cytochrome P450 3A4
Source:NCBIAccessed: 31 August, 2019


What does this gene/protein do?
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Pathways:What pathways are this gene/protein implicaed in?
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Cancer Overview

Research Indicators

Publications Per Year (1994-2019)
Graph generated 31 August 2019 using data from PubMed using criteria.

Literature Analysis

Mouse over the terms for more detail; many indicate links which you can click for dedicated pages about the topic.

Tag cloud generated 31 August, 2019 using data from PubMed, MeSH and CancerIndex

Specific Cancers (6)

Data table showing topics related to specific cancers and associated disorders. Scope includes mutations and abnormal protein expression.

Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).

Latest Publications: CYP3A4 (cancer-related)

Annalora AJ, Jozic M, Marcus CB, Iversen PL
Alternative splicing of the vitamin D receptor modulates target gene expression and promotes ligand-independent functions.
Toxicol Appl Pharmacol. 2019; 364:55-67 [PubMed] Related Publications
Alternative splicing modulates gene function by creating splice variants with alternate functions or non-coding RNA activity. Naturally occurring variants of nuclear receptor (NR) genes with dominant negative or gain-of-function phenotypes have been documented, but their cellular roles, regulation, and responsiveness to environmental stress or disease remain unevaluated. Informed by observations that class I androgen and estrogen receptor variants display ligand-independent signaling in human cancer tissues, we questioned whether the function of class II NRs, like the vitamin D receptor (VDR), would also respond to alternative splicing regulation. Artificial VDR constructs lacking exon 3 (Dex3-VDR), encoding part of the DNA binding domain (DBD), and exon 8 (Dex8-VDR), encoding part of the ligand binding domain (LBD), were transiently transfected into DU-145 cells and stably-integrated into Caco-2 cells to study their effect on gene expression and cell viability. Changes in VDR promoter signaling were monitored by the expression of target genes (e.g. CYP24A1, CYP3A4 and CYP3A5). Ligand-independent VDR signaling was observed in variants lacking exon 8, and a significant loss of gene suppressor function was documented for variants lacking exon 3. The gain-of-function behavior of the Dex8-VDR variant was recapitulated in vitro using antisense oligonucleotides (ASO) that induce the skipping of exon 8 in wild-type VDR. ASO targeting the splice acceptor site of exon 8 significantly stimulated ligand-independent VDR reporter activity and the induction of CYP24A1 above controls. These results demonstrate how alternative splicing can re-program NR gene function, highlighting novel mechanisms of toxicity and new opportunities for the use of splice-switching oligonucleotides (SSO) in precision medicine.

Veiga MG, Felizi RT, Reis DG, et al.
The Influence of CYP3A4 Polymorphism in Sex Steroids as a Risk Factor for Breast Cancer.
Rev Bras Ginecol Obstet. 2018; 40(11):699-704 [PubMed] Related Publications
OBJECTIVE:  Epidemiological studies have shown evidence of the effect of sex hormones in the pathogenesis of breast cancer, and have suggested a relationship of the disease with variations in genes involved in estrogen synthesis and/or metabolism. The aim of the present study was to evaluate the association between the
METHODS:  In the present case-control study, the frequency of the
RESULTS:  After adjusting for confounding variables, we have found that the polymorphism was not associated with the occurrence of breast cancer (odds ratio = 1.151; 95% confidence interval: 0.714-1.856;
CONCLUSION:  We have not observed a relationship between the

Valencia-Cervantes J, Huerta-Yepez S, Aquino-Jarquín G, et al.
Hypoxia increases chemoresistance in human medulloblastoma DAOY cells via hypoxia‑inducible factor 1α‑mediated downregulation of the CYP2B6, CYP3A4 and CYP3A5 enzymes and inhibition of cell proliferation.
Oncol Rep. 2019; 41(1):178-190 [PubMed] Free Access to Full Article Related Publications
Medulloblastomas are among the most frequently diagnosed pediatric solid tumors, and drug resistance remains as the principal cause of treatment failure. Hypoxia and the subsequent activation of hypoxia‑inducible factor 1α (HIF‑1α) are considered key factors in modulating drug antitumor effectiveness, but the underlying mechanisms in medulloblastomas have not yet been clearly understood. The aim of the present study was to determine whether hypoxia induces resistance to cyclophosphamide (CPA) and ifosfamide (IFA) in DAOY medulloblastoma cells, whether the mechanism is dependent on HIF‑1α, and whether involves the modulation of the expression of cytochromes P450 (CYP)2B6, 3A4 and 3A5 and the control of cell proliferation. Monolayer cultures of DAOY medulloblastoma cells were exposed for 24 h to moderate (1% O2) or severe (0.1% O2) hypoxia, and protein expression was evaluated by immunoblotting. Cytotoxicity was studied with the MTT assay and by Annexin V/PI staining and flow cytometry. Cell proliferation was determined by the trypan‑blue exclusion assay and cell cycle by propidium iodide staining and flow cytometry. Hypoxia decreased CPA and IFA cytotoxicity in medulloblastoma cells, which correlated with a reduction in the protein levels of CYP2B6, CYP3A4 and CYP3A5 and inhibition of cell proliferation. These responses were dependent on hypoxia‑induced HIF‑1α activation, as evidenced by chemical inhibition of its transcriptional activity with 2‑methoxyestradiol (2‑ME), which enhanced the cytotoxic activity of CPA and IFA and increased apoptosis. Our results indicate that by stimulating HIF‑1α activity, hypoxia downregulates the expression of CYP2B6, CYP3A4 and CYP3A5, that in turn leads to decreased conversion of CPA and IFA into their active forms and thus to diminished cytotoxicity. These results support that the combination of HIF‑1α inhibitors and canonical antineoplastic agents provides a potential therapeutic alternative against medulloblastoma.

Guo XG, Wang ZH, Dong W, et al.
Specific CYP450 Genotypes in the Chinese Population Affect Sorafenib Toxicity in HBV/HCV-associated Hepatocellular Carcinoma Patients.
Biomed Environ Sci. 2018; 31(8):586-595 [PubMed] Related Publications
OBJECTIVE: The purpose of this study was to screen for frequencies of different CYP450 genotypes in the Chinese population and explore the relationship between sorafenib toxicity and CYP450 polymorphism.
METHODS: A total of 600 peripheral blood samples were obtained from two groups for this study. The first group of 300 samples were from Chinese patients with HBV/HCV-associated HCC, while the remaining 300 samples were from a healthy population of recruited subjects. Allele-specific PCR and long-fragment gene sequencing was used to identify the frequencies of CYP450 polymorphism. Aflatoxin-induced HCC rat models expressing CYP3A4*1, CYP3A5*3, CYP2C19*2, and CYP2D6*10 were established and treated with sorafenib at certain time points. Hepatic and renal function, along with plasma concentration of sorafenib, were monitored regularly.
RESULTS: The most common forms of CYP mutations in the Chinese population were identified. The levels of sorafenib plasma concentration, as well as damage to hepatic and renal function in aflatoxin-induced HCC rat models varied significantly across the different CYP genotypes.
CONCLUSION: The mutational frequencies of CYP3A5, CYP3A4, CYP2C19, and CYP2D6 genotypes varied among different ethnic groups and populations. Individuals with CYP3A5*3 demonstrated minimal sorafenib metabolism, which led to severe hepatic and renal damage. Inter-individual variability in sorafenib-toxicity may be interpreted by CYP450 genetic polymorphisms, suggesting that identification of CYP polymorphism within a certain population should be considered in sorafenib therapy.

Liu X, Huang X, Zhang S, et al.
Correlations between CYP3A4 polymorphism and susceptibility to breast cancer in Chinese Han population.
Int J Clin Oncol. 2019; 24(2):179-188 [PubMed] Related Publications
BACKGROUND: CYP3A4 is a major enzyme catalyzing the metabolism of endogenous steroids that play an important role in the etiology of carcinogenesis. This study was designed to investigate the contribution of CYP3A4 polymorphism to breast cancer in Chinese Han female population.
METHODS: To examine whether variants of CYP3A4 contribute to breast cancer, 5 single-nucleotide polymorphisms (SNPs) of CYP3A4 were genotyped by Sequenom MassARRAY in 267 breast cancer patients and 302 healthy controls. Odds ratio (OR) and 95% confidence intervals (CIs) were calculated by unconditional logistic regression adjusted for age.
RESULTS: We found that the TT genotype of CYP3A4*1G (rs2242480) polymorphism was associated with increased risk of breast cancer using the fixed effects model (recessive model: OR = 2.34, p = 0.018). Stratified according to age, CYP3A4*1G increased the risk of breast cancer especially in less than 50-year-old group (codominant model OR = 3.68, p = 0.041; recessive model: OR = 3.55, p = 0.012). Furthermore, TT genotype of rs2242480 was associated with Cerb-B2 positive (recessive model: OR = 2.47, p = 0.025) and stage I/II (recessive model: OR = 2.32, p = 0.041). However, no statistically significant associations in other polymorphisms and haploview analysis were observed.
CONCLUSIONS: This study provides an evidence for polymorphism of CYP3A4 gene associated with the development of breast cancer, also a new insight into etiology of breast cancer. However, the underlying mechanism of the CYP3A4 gene in breast cancer is necessary for further study.

Wasiewicz T, Piotrowska A, Wierzbicka J, et al.
Antiproliferative Activity of Non-Calcemic Vitamin D Analogs on Human Melanoma Lines in Relation to VDR and PDIA3 Receptors.
Int J Mol Sci. 2018; 19(9) [PubMed] Free Access to Full Article Related Publications
Vitamin D is a precursor for secosteroidal hormones, which demonstrate pleiotropic biological activities, including the regulation of growth and the differentiation of normal and malignant cells. Our previous studies have indicated that the inhibition of melanoma proliferation by a short side-chain, low calcemic analog of vitamin D-21(OH)pD is not fully dependent on the expression of vitamin D receptor (VDR). We have examined the effects of classic vitamin D metabolites, 1,25(OH)₂D₃ and 25(OH)D₃, and two low calcemic vitamin D analogs, (21(OH)pD and calcipotriol), on proliferation, mRNA expression and vitamin D receptor (VDR) translocation in three human melanoma cell lines: WM98, A375 and SK-MEL-188b (subline b of SK-MEL-188, which lost responsiveness to 1,25(OH)₂D₃ and became VDR

Ren X, Ji Y, Jiang X, Qi X
Downregulation of CYP2A6 and CYP2C8 in Tumor Tissues Is Linked to Worse Overall Survival and Recurrence-Free Survival from Hepatocellular Carcinoma.
Biomed Res Int. 2018; 2018:5859415 [PubMed] Free Access to Full Article Related Publications
Objective: This study aimed to evaluate the links between CYP450 family genes in tumor tissues and hepatocellular carcinoma (HCC) outcomes.
Methods: Gene Expression Omnibus (GEO) databases GSE14520 and GSE36376 were used to identify differential expressed CYP450 genes between tumor and nontumor tissues and related to HCC clinicopathological features and survivals.
Results: Seven CYP450 genes including CYP1A2, CYP2A6, CYP2C8, CYP2C9, CYP2E1, CYP3A4, and CYP4A11 were downregulated in tumor tissues, which were validated in both GSE14520 and GSE36376. HCC patients with CYP2A6 and CYP2C8 low levels in tumor tissues suffered from poorer overall survival (OS) compared to those with high CYP2A6 and CYP2C8 in GSE14520 profile (log ranks
Conclusion: Downregulation of CYP2A6 and CYP2C8 in tumor tissues links to poorer OS and RFS in HCC patients.

Zheng Y, Xu Y, Zhou BY, et al.
CYP3A4*1B Polymorphism and Cancer Risk: A Meta-Analysis Based on 55 Case-control Studies.
Ann Clin Lab Sci. 2018; 48(4):538-545 [PubMed] Related Publications
Published data on the association between CYP3A4*1B polymorphism and cancer risk are inconclusive. To derive a more precise estimation of the association, we conducted a meta-analysis. A systematic search of the PubMed database was performed. A total of 55 separate studies including 22072 cancer cases and 25433 controls were involved in this meta-analysis. We found a significant association between CYP3A4*1B and cancer risk in the overall population in dominant model (AG+GG vs. AA: OR=1.142, 95% CI=1.006-1.295). No significant association was found in recessive model (GG vs. AG+AA: OR=1.156, 95% CI=0.941-1.419), heterozygous model (AG vs. AA: OR=1.109, 95% CI=0.977-1.259), or homozygous model (GG vs. AA: OR=1.213, 95% CI=0.950-1.549). We performed subgroup meta-analysis based on the difference of ethnicity and cancer type. Ethnic subgroup analyses revealed no significant associations of African or Caucasian ethnicities in any genetic models. In the subgroup analysis by Cancer types, we observed an increased risk for leukemia in dominant model and heterozygous model. Excluding studies with controls not in HWE, a significant association was found in dominant model and heterozygous model. In summary, this meta-analysis suggests that the CYP3A4*1B polymorphism might play a modest role in susceptibility to cancer, especially for leukemia.

Lepri SR, Sartori D, Semprebon SC, et al.
Genistein Affects Expression of Cytochrome P450 (CYP450) Genes in Hepatocellular Carcinoma (HEPG2/C3A) Cell Line.
Drug Metab Lett. 2018; 12(2):138-144 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Genistein (5,7-Dihydroxy-3-(4-hydroxyphenyl)-4H-1-benzopyran-4-one) is the most abundant isoflavone in soybean, which has been associated with a lower risk of development of cancer and cardiovascular diseases. Of particular interest regarding cancer preventive properties of flavonoids is their interaction with cytochrome P450 enzymes (CYPs). However, contradictory data report the effect of genistein on expression of СYPs enzymes.
OBJECTIVE: The aim of this study was to investigate the effects of genistein on cytochrome P450 (CYP) gene expression levels in human hepatocellular carcinoma (HepG2/C3A) and colon adenocarcinoma (HT29) cells.
METHODS: Real-time RT-PCR was used to examine the expression of genes families involved in xenobiotic metabolism, such as CYP1 (CYP1A1, CYP1B1), CYP2 (CYP2E1, CYP2D6), CYP3 (CYP3A4); and of a family involved in the catabolism of the all-trans-retinoic acid (ATRA), CYP26 (CYP26A1, CYP26B1).
RESULTS: RT-qPCR data analysis showed that after 12 h of exposure of HepG2/C3A cells to genistein (5 and 50 µM) there was an upregulation of CYP1A1 and CYP1B1 and downregulation of CYP2D6, CYP26A1 and CYP26B1 mRNA levels. There was no change in the mRNA levels of CYP P450 genes in HT29 cells.
CONCLUSION: Our results suggest that treatment with genistein in non-toxic concentrations may impact the expression level of CYPs involved in the biotransformation of xenobiotics and drug metabolizing enzymes. Moreover, the downregulation of ATRA metabolism-related genes opens a new research path for the study of genistein as retinoic acid metabolism blocking agent for treating cancer and other pathologies.

Yoshimaru S, Shizu R, Tsuruta S, et al.
Acceleration of murine hepatocyte proliferation by imazalil through the activation of nuclear receptor PXR.
J Toxicol Sci. 2018; 43(7):443-450 [PubMed] Related Publications
The nuclear receptor pregnane X receptor (PXR) plays a major role in the xenobiotic-induced expression of drug-metabolizing enzymes. PXR activation is also associated with several adverse events in the liver. Especially, the receptor enhances hepatocyte proliferation mediated by chemical liver tumor promoters, suggesting that exposure to PXR activators increases the risk of liver cancer. In this study, we have investigated the influences of food additives on PXR to understand their potential adverse effects when they are taken in combination with other chemical compounds. We first screened 25 food additives and related compounds for their PXR-activating ability using reporter assays in HepG2 cells expressing mouse PXR, and found that imazalil dose-dependently activated mouse PXR. Next, to investigate whether imazalil could activate mouse PXR in vivo, mice were treated with imazalil and we found that imazalil treatment increased hepatic mRNA levels of Cyp3a11, a PXR target gene. Finally, to investigate the influence of imazalil exposure on the hepatocyte proliferation induced by nuclear receptor constitutive active/androstane receptor (CAR), mice were treated with imazalil with or without mouse CAR activator TCPOBOP. Although imazalil alone did not induce hepatocyte proliferation, co-treatment with imazalil facilitated the TCPOBOP-dependent proliferation, indicated by the increases in cell proliferation marker levels, Ki-67-positive nuclei and Mcm2 mRNA levels. These results suggest that in mice imazalil activates PXR to enhance hepatocyte proliferation mediated by CAR-activating liver tumor promoters.

Liang Y, Han W, Yan H, Mao Q
Association of
J Cancer Res Ther. 2018; 14(Supplement):S463-S467 [PubMed] Related Publications
Aim of Study: The CYP3A5*3 allele (A6986G transition in intron 3) is the major member of cytochrome P450 subfamily, which plays a pivotal role in exogenous carcinogens of liver. Variation of the CYP3A5*3 (rs776746 A > G) can lead to oxidation and inactivation of testosterone, which may result in individual susceptibility to prostate cancer.
Methods: All eligible published studies about association between CYP3A5*3 polymorphisms and prostate cancer risk were searched in PubMed, Embase, Web of Science, and Cochrane Library, for the period up to August 2015. Odds ratios (ORs) together with 95% confidence intervals (95% CIs) were used to access the strength of the association.
Results: Six case-control studies including 2522 cancer patients and 2444 healthy controls were finally included. The meta-analysis results suggested that CYP3A5*3 polymorphisms were significantly associated with an increased risk of prostate cancer under two genetic models (GG + AG vs. AA: OR = 1.53, 95% CI = 1.23-1.90, P = 0.000; GG vs. AA: OR = 1.46, 95% CI = 1.14-1.87, P = 0.000). Further subgroup analysis according to ethnicity indicated that CYP3A5*3 polymorphism may increase the risks of prostate cancer among African (G allele vs. A allele: OR = 1.34, 95% CI = 1.14-1.57, P = 0.000; GG + AG vs. AA: OR = 1.606, 95% CI = 1.27-2.04, P = 0.000). Sensitivity analysis indicated a reliable result and publication bias suggested no strong publication bias under the genetic models.
Conclusion: Our data support that the CYP3A5*3 polymorphism may be associated with increased risk of prostate cancer, particularly in African populations. Large and well-designed studies are needed to validate this association.

Sági JC, Egyed B, Kelemen A, et al.
Possible roles of genetic variations in chemotherapy related cardiotoxicity in pediatric acute lymphoblastic leukemia and osteosarcoma.
BMC Cancer. 2018; 18(1):704 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: The treatment of acute lymphoblastic leukemia (ALL) and osteosarcoma (OSC) is very effective: the vast majority of patients recover and survive for decades. However, they still need to face serious adverse effects of chemotherapy. One of these is cardiotoxicity which may lead to progressive heart failure in the long term. Cardiotoxicity is contributed mainly to the use of anthracyclines and might have genetic risk factors. Our goal was to test the association between left ventricular function and genetic variations of candidate genes.
METHODS: Echocardiography data from medical records of 622 pediatric ALL and 39 OSC patients were collected from the period 1989-2015. Fractional shortening (FS) and ejection fraction (EF) were determined, 70 single nucleotide polymorphisms (SNPs) in 26 genes were genotyped. Multivariate logistic regression and multi-adjusted general linear model were performed to investigate the influence of genetic polymorphisms on the left ventricular parameters. Bayesian network based Bayesian multilevel analysis of relevance (BN-BMLA) method was applied to test for the potential interaction of the studied cofactors and SNPs.
RESULTS: Our results indicate that variations in ABCC2, CYP3A5, NQO1, SLC22A6 and SLC28A3 genes might influence the left ventricular parameters. CYP3A5 rs4646450 TT was 17% among ALL cases with FS lower than 28, and 3% in ALL patients without pathological FS (p = 5.60E-03; OR = 6.94 (1.76-27.39)). SLC28A3 rs7853758 AA was 12% in ALL cases population, while only 1% among controls (p = 6.50E-03; OR = 11.56 (1.98-67.45)). Patients with ABCC2 rs3740066 GG genotype had lower FS during the acute phase of therapy and 5-10 years after treatment (p = 7.38E-03, p = 7.11E-04, respectively). NQO1 rs1043470 rare T allele was associated with lower left ventricular function in the acute phase and 5-10 years after the diagnosis (p = 4.28E-03 and 5.82E-03, respectively), and SLC22A6 gene rs6591722 AA genotype was associated with lower mean FS (p = 1.71E-03), 5-10 years after the diagnosis.
CONCLUSIONS: Genetic variants in transporters and metabolic enzymes might modulate the individual risk to cardiac toxicity after chemotherapy.

Kvist AJ, Kanebratt KP, Walentinsson A, et al.
Critical differences in drug metabolic properties of human hepatic cellular models, including primary human hepatocytes, stem cell derived hepatocytes, and hepatoma cell lines.
Biochem Pharmacol. 2018; 155:124-140 [PubMed] Related Publications
Primary human hepatocytes (PHH), HepaRG™, HepG2, and two sources of induced pluripotent stem cell (iPSC) derived hepatocytes were characterized regarding gene expression and function of key hepatic proteins, important for the metabolic fate of drugs. The gene expression PCA analysis showed a distance between the two iPSC derived hepatocytes as well as the HepG2 and HepaRG™ cells to the three PHH donors and PHH pool, which were clustered more closely together. Correlation-based hierarchical analysis clustered HepG2 close to the stem cell derived hepatocytes both when the expression of 91 genes related to liver function or only cytochrome P450 (P450) genes were analyzed indicating the non-liver feature and a similar low P450 profile in these cell models. The specific P450 activities and the metabolic pattern of well-characterized drug substances in the cell models demonstrated that iPSC derived hepatocytes had modest levels of CYP3A and CYP2C9, while CYP1A2, 2B6, 2C8, 2C9, 2C19, and 2D6 were barely detectable. High expression of several extrahepatic P450s such as CYP1A1 and 1B1 detected in the stem cell derived hepatocytes may have significant effects on metabolite profiles. However, one of the iPSC derived hepatocytes demonstrated significant combined P450 and conjugating enzyme activity of certain drugs. HepaRG™ cells showed many metabolic properties similar to PHHs and will in many respects be a good model in studies of metabolic pathways and induction of drug metabolism whereas there is still ground to cover before iPSC derived hepatocytes will be seen as a substitute to PHH in drug metabolism studies.

Chen Y, Chen Q, Zou J, et al.
Construction and analysis of a ceRNA‑ceRNA network reveals two potential prognostic modules regulated by hsa‑miR‑335‑5p in osteosarcoma.
Int J Mol Med. 2018; 42(3):1237-1246 [PubMed] Free Access to Full Article Related Publications
Osteosarcoma is an aggressive cancer of the skeletal system, which is associated with a poor prognosis due to the high recurrence rate. Although previous studies have revealed that competitive endogenous RNAs (ceRNAs) are involved in various biological processes in the physiology and development of osteosarcoma, the roles of ceRNAs in osteosarcoma recurrence remain largely unexplored. The present study constructed a ceRNA‑ceRNA network for osteosarcoma by systematically integrating matched expression profiles for microRNAs (miRNAs/miRs) and mRNAs, and identified two ceRNA‑mediated modules that were associated with recurrence in patients with osteosarcoma. A multivariate Cox regression analysis demonstrated that the recurrence‑free prognosis associated with the expression of the two modules was independent of other clinical factors. In addition, hsa‑miR‑335‑3p was identified as an upstream regulating factor for both modules. In conclusion, the results of the present study suggested that ceRNAs may act as potential therapeutic biomarkers for predicting the recurrence of osteosarcoma, and may help to identify patients with osteosarcoma at a high risk of recurrence, who may benefit from adjuvant therapy.

Cortes J, Tamura K, DeAngelo DJ, et al.
Phase I studies of AZD1208, a proviral integration Moloney virus kinase inhibitor in solid and haematological cancers.
Br J Cancer. 2018; 118(11):1425-1433 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Proviral integration Moloney virus (PIM) kinases (PIM1, 2 and 3) are overexpressed in several tumour types and contribute to oncogenesis. AZD1208 is a potent ATP-competitive PIM kinase inhibitor investigated in patients with recurrent or refractory acute myeloid leukaemia (AML) or advanced solid tumours.
METHODS: Two dose-escalation studies were performed to evaluate the safety and tolerability, and to define the maximum tolerated dose (MTD), of AZD1208 in AML and solid tumours. Secondary objectives were to evaluate the pharmacokinetics, pharmacodynamics (PD) and preliminary efficacy of AZD1208.
RESULTS: Sixty-seven patients received treatment: 32 in the AML study over a 120-900 mg dose range, and 25 in the solid tumour study over a 120-800 mg dose range. Nearly all patients (98.5%) in both studies experienced adverse events, mostly gastrointestinal (92.5%). Dose-limiting toxicities included rash, fatigue and vomiting. AZD1208 was not tolerated at 900 mg, and the protocol-defined MTD was not confirmed. AZD1208 increased CYP3A4 activity after multiple dosing, resulting in increased drug clearance. There were no clinical responses; PD analysis showed biological activity of AZD1208.
CONCLUSIONS: Despite the lack of single-agent clinical efficacy with AZD1208, PIM kinase inhibition may hold potential as an anticancer treatment, perhaps in combination with other agents.

Abumiya M, Mita A, Takahashi S, et al.
Effects of polymorphisms in NR1I2, CYP3A4, and ABC transporters on the steady-state plasma trough concentrations of bosutinib in Japanese patient with chronic myeloid leukemia.
Med Oncol. 2018; 35(6):90 [PubMed] Related Publications
We investigated the effects of polymorphisms in NR1I2 (7635A>G, 8055C>T), CYP3A4 (20230G>A), ABCB1 (1199G>A, 1236C>T, 2677G>T/A, 3435C>T), and ABCG2 (421C>A) on the mean plasma trough concentrations (C

Molina-Ortiz D, Torres-Zárate C, Cárdenas-Cardós R, et al.
MDR1 not CYP3A4 gene expression is the predominant mechanism of innate drug resistance in pediatric soft tissue sarcoma patients.
Cancer Biomark. 2018; 22(2):317-324 [PubMed] Related Publications
BACKGROUND: Intratumoral up-regulation of genes coding for drug transporters and metabolizing enzymes, such as MDR1 and CYP3A4, after chemotherapy are linked to cancer drug resistance. However their expression in primary soft tissue sarcomas (STS) prior to drug treatment and their role in innate resistance remain unclear.
OBJECTIVE: The aim of this study was characterize MDR1 and CYP3A4 expression pattern before to chemotherapy and its clinical implication in pediatric STS.
METHODS: In this prospective study we analyzed MDR1 and CYP3A4 mRNA expression in both normal and tumor tissues from 28 newly diagnosed STS pediatric and then compared with patients' clinical-pathological data, including chemotherapy response.
RESULTS: Our data showed that the expression of the MDR1 gene was significantly higher in malignant tissue than in the normal tissues of patients with STS. In addition, high MDR1 expression was significantly associated with local advances, as well as poor response to treatment. In contrast, CYP3A4 expression level was negligible in both tumoral and non-tumoral tissues.
CONCLUSIONS: These results suggest that a significant mRNA level of MDR1 gene was intrinsically present in STS before exposure to chemotherapeutic drugs, suggesting that MDR1 may be important contributors of innate chemoresistance of this tumor type.

Nasr T, Bondock S, Rashed HM, et al.
Novel hydrazide-hydrazone and amide substituted coumarin derivatives: Synthesis, cytotoxicity screening, microarray, radiolabeling and in vivo pharmacokinetic studies.
Eur J Med Chem. 2018; 151:723-739 [PubMed] Related Publications
The current work presents the synthesis and biological evaluation of new series of coumarin hydrazide-hydrazone derivatives that showed in vitro broad spectrum antitumor activities against resistant pancreatic carcinoma (Panc-1), hepatocellular carcinoma (HepG2) and leukemia (CCRF) cell lines using doxorubicin as reference standard. Bromocoumarin hydrazide-hydrazone derivative (BCHHD) 11b showed excellent anticancer activity against all tested cancer cell lines. Enzyme assays showed that BCHHD 11b induced apoptosis due to activation of caspases 3/7. Moreover, 11b inhibited GST and CYP3A4 in a dose dependent manner and the induced cell death could be attributed to metabolic inhibition. Moreover, 11b microarray analysis showed significant up- and down-regulation of many genes in the treated cells related to apoptosis, cell cycle, tumor growth and suppressor genes. All of the above presents BCHHD 11b as a potent anticancer agent able to overcome drug resistance. In addition, compound 11b was able to serve as a chemical carrier for

Riera P, Salazar J, Virgili AC, et al.
Relevance of CYP3A4*20, UGT1A1*37 and UGT1A1*28 variants in irinotecan-induced severe toxicity.
Br J Clin Pharmacol. 2018; 84(6):1389-1392 [PubMed] Free Access to Full Article Related Publications
Severe irinotecan-induced toxicity is associated with UGT1A1 polymorphisms. However, some patients develop side-effects despite harbouring a normal UGT1A1 genotype. As CYP3A4 is also an irinotecan-metabolizing enzyme, our study aimed to elucidate the influence of the CYP3A4*20 loss-of-function allele in the toxicity profile of these patients. Three-hundred and eight metastatic colorectal cancer patients treated with an irinotecan-containing chemotherapy were studied. The presence of CYP3A4*20, UGT1A1*37 and UGT1A1*28 alleles was tested. Associations between these genetic variants and toxicity were evaluated. UGT1A1*28 was significantly associated with severe diarrhoea, neutropenia and asthenia (P = 0.002, P = 0.037 and P = 0.041, respectively). One patient with the UGT1A1*28/*37 genotype presented with grade IV neutropenia and lethal septic shock. One heterozygous UGT1A1 (*1/*28) patient also carried the CYP3A4*20 allele but did not develop toxicity. We confirm that UGT1A1*37 and UGT1A1*28 are associated with severe toxicity and suggest that the CYP3A4*20 allele does not play a role in irinotecan-induced toxicity.

Fiszer-Maliszewska Ł, Łaczmański Ł, Dolińska A, et al.
Polymorphisms of
Anticancer Res. 2018; 38(3):1455-1459 [PubMed] Related Publications
BACKGROUND/AIM: Ovarian cancer is a lethal gynecological malignancy, with 5-year survival of only about one third of patients. The ABCB1 gene encodes the P-glycoprotein which is one of the multidrug efflux pumps. Its decreased activity may result in multidrug resistance of cancer cells. Drug-metabolizing enzymes Cyp3A4 and Cyp3A5 may affect success of chemotherapy. In this study we attempted to examine the effects of 12 single nucleotide polymorphisms (SNPs) of the ABCB1 gene and one SNP in each of CYP3A4 and CYP3A5 genes on the incidence of ovarian cancer in Polish women and their response to treatment.
MATERIALS AND METHODS: Our study included 276 patients and 369 healthy control women.
RESULTS: The results showed no significant differences between patients and controls in allele frequencies of the tested SNPs, with one exception: rs2157926T allele decreased cancer risk by 99.4% (odds ratio, 0.006). Moreover, rs2032582T increased fourfold the risk of metastasis. Finally, rs1128503CC genotype prolonged survival (p=0.024778).
CONCLUSION: These findings may contribute to a better prediction of therapy outcome.

Thota K, Prasad K, Basaveswara Rao MV
Detection of Cytochrome P450 Polymorphisms in Breast Cancer Patients May Impact on Tamoxifen Therapy
Asian Pac J Cancer Prev. 2018; 19(2):343-350 [PubMed] Free Access to Full Article Related Publications
Background: Breast cancer is the most common cancer among women worldwide. Tamoxifen (TAM), a selective estrogen receptor modulator, is widely used in its treatment. TAM is metabolized by cytochrome P450 (CYP450) enzymes, including CYP2D6, CYP3A5 and CYP2C19, whose genetic variations may have clinicopathological importance. However, reports on the association of various P450 polymorphisms with certain cancers are contradictory. Methods: We here investigated whether the prevalence of the four most common polymorphism in the CYP2D6*4 (G1934A), CYP2D6*10 (C188T), CYP3A5*3 and CYP2C19*2 alleles has any link with breast cancer using genomic DNA and polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analysis. Results: Prevalences of CYP2D6*4, CYP2D6*10 and CYP2C19*2 genotypes were differed significantly (P = 0.01 and P = 0.004) between breast cancer patients and controls. The CYP3A5*3 genotype did not demonstrate statistically significant variation. Conclusion: Polymorphisms in CYP2 appear to be associated with breast cancer risk. Our data taken together with other reports indicates that drug resistance gene polymorphisms might be indicators of response to tamoxifen therapy in breast cancer cases.

Willis AJ, Indra R, Wohak LE, et al.
The impact of chemotherapeutic drugs on the CYP1A1-catalysed metabolism of the environmental carcinogen benzo[a]pyrene: Effects in human colorectal HCT116 TP53(+/+), TP53(+/-) and TP53(-/-) cells.
Toxicology. 2018; 398-399:1-12 [PubMed] Free Access to Full Article Related Publications
Polycyclic aromatic hydrocarbons such as benzo[a]pyrene (BaP) can induce cytochrome P450 1A1 (CYP1A1) via a p53-dependent mechanism. The effect of different p53-activating chemotherapeutic drugs on CYP1A1 expression, and the resultant effect on BaP metabolism, was investigated in a panel of isogenic human colorectal HCT116 cells with differing TP53 status. Cells that were TP53(+/+), TP53(+/-) or TP53(-/-) were treated for up to 48 h with 60 μM cisplatin, 50 μM etoposide or 5 μM ellipticine, each of which caused high p53 induction at moderate cytotoxicity (60-80% cell viability). We found that etoposide and ellipticine induced CYP1A1 in TP53(+/+) cells but not in TP53(-/-) cells, demonstrating that the mechanism of CYP1A1 induction is p53-dependent; cisplatin had no such effect. Co-incubation experiments with the drugs and 2.5 μM BaP showed that: (i) etoposide increased CYP1A1 expression in TP53(+/+) cells, and to a lesser extent in TP53(-/-) cells, compared to cells treated with BaP alone; (ii) ellipticine decreased CYP1A1 expression in TP53(+/+) cells in BaP co-incubations; and (iii) cisplatin did not affect BaP-mediated CYP1A1 expression. Further, whereas cisplatin and etoposide had virtually no influence on CYP1A1-catalysed BaP metabolism, ellipticine treatment strongly inhibited BaP bioactivation. Our results indicate that the underlying mechanisms whereby etoposide and ellipticine regulate CYP1A1 expression must be different and may not be linked to p53 activation alone. These results could be relevant for smokers, who are exposed to increased levels of BaP, when prescribing chemotherapeutic drugs. Beside gene-environment interactions, more considerations should be given to potential drug-environment interactions during chemotherapy.

Khan BA, Robinson R, Fohner AE, et al.
Cytochrome P450 Genetic Variation Associated with Tamoxifen Biotransformation in American Indian and Alaska Native People.
Clin Transl Sci. 2018; 11(3):312-321 [PubMed] Free Access to Full Article Related Publications
Despite evidence that pharmacogenetics can improve tamoxifen pharmacotherapy, there are few studies with American Indian and Alaska Native (AIAN) people. We examined variation in cytochrome P450 (CYP) genes (CYP2D6, CYP3A4, CYP3A5, and CYP2C9) and tamoxifen biotransformation in AIAN patients with breast cancer (n = 42) from the Southcentral Foundation in Alaska and the Confederated Salish and Kootenai Tribes in Montana. We tested for associations between CYP diplotypes and plasma concentrations of tamoxifen and metabolites. Only the CYP2D6 variation was significantly associated with concentrations of endoxifen (P = 0.0008) and 4-hydroxytamoxifen (P = 0.0074), tamoxifen's principal active metabolites, as well as key metabolic ratios. The CYP2D6 was also the most significant predictor of active metabolites and metabolic ratios in a multivariate regression model, including all four genes as predictors, with minor roles for other CYP genes. In AIAN populations, CYP2D6 is the largest contributor to tamoxifen bioactivation, illustrating the importance of validating pharmacogenetic testing for therapy optimization in an understudied population.

Cargnin S, Ravegnini G, Soverini S, et al.
Impact of SLC22A1 and CYP3A5 genotypes on imatinib response in chronic myeloid leukemia: A systematic review and meta-analysis.
Pharmacol Res. 2018; 131:244-254 [PubMed] Related Publications
Contrasting results have been reported on the role of rs628031 and rs683369 polymorphisms of SLC22A1 and rs776746 of CYP3A5 on imatinib treatment response in patients with chronic myeloid leukemia (CML). In the present study, we conducted a systematic review and meta-analysis of published studies to estimate the impact of the above-mentioned gene variants on major molecular response (MMR) or complete cytogenetic response (CCyR) in imatinib-treated CML patients. We performed a comprehensive search through PubMed, Web of Knowledge, and Cochrane databases up to September 2017. The pooled analyses showed association between carriers of SLC22A1 rs628031A allele (GA + AA vs GG, OR: 0.58, 95% CI: 0.38-0.88, P = 0.011) or rs683369G allele (CG + GG vs CC, OR: 0.64, 95% CI: 0.42-0.96, P = 0.032) and a lower MMR rate. The combined analyses also revealed a correlation between the dominant (GG + AG vs AA, OR: 2.43, 95%CI: 1.12-5.27, P = 0.024) or the allelic model (G vs A, OR: 1.72, 95% CI: 1.09-2.72, P = 0.020) of CYP3A5 rs776746 with higher CCyR rates. The subsequent sensitivity analysis confirmed the statistical significance of CYP3A5 rs776746 among Asian CML patients (dominant model OR: 3.90; 95%CI: 2.47-6.14, P < 0.001; allelic model OR: 2.08; 95% CI: 1.47-2.95, P < 0.001). In conclusion, the present meta-analysis supports the association of SLC22A1 and CYP3A5 genotypes with clinical imatinib response rates of CML patients, nevertheless further large studies, particularly in Caucasians, are still warranted to provide conclusive evidences.

Stewart MD, Zelin E, Dhall A, et al.
BARD1 is necessary for ubiquitylation of nucleosomal histone H2A and for transcriptional regulation of estrogen metabolism genes.
Proc Natl Acad Sci U S A. 2018; 115(6):1316-1321 [PubMed] Free Access to Full Article Related Publications
Missense mutations that disrupt the RING domain of the tumor suppressor gene

Endo-Tsukude C, Sasaki JI, Saeki S, et al.
Population Pharmacokinetics and Adverse Events of Erlotinib in Japanese Patients with Non-small-cell Lung Cancer: Impact of Genetic Polymorphisms in Metabolizing Enzymes and Transporters.
Biol Pharm Bull. 2018; 41(1):47-56 [PubMed] Related Publications
Determinants of interindividual variability in erlotinib pharmacokinetics (PK) and adverse events remain to be elucidated. This study with 50 Japanese non-small-cell lung cancer patients treated with oral erlotinib at a standard dose of 150 mg aimed to investigate whether genetic polymorphisms affect erlotinib PK and adverse events. Single nucleotide polymorphisms (SNPs) in genes encoding metabolizing enzymes (CYP1A1, CYP1A2, CYP2D6, CYP3A4, CYP3A5, UGT1A1, UGT2B7, GSTM1, and GSTT1) or efflux transporters (ABCB1, and ABCG2) were analyzed as covariates in a population PK model. The ABCB1 1236C>T (rs1128503) polymorphism, not ABCB1*2 haplotype (1236TT-2677TT-3455TT, rs1128503 TT-rs2032582 TT-rs1045642 TT), was a significant covariate for the apparent clearance (CL/F), with the TT genotype showing a 29.4% decrease in CL/F as compared with the CC and the CT genotypes. A marginally higher incidence of adverse events (mainly skin rash) was observed in the TT genotype group; however, patients with high plasma erlotinib exposure did not always experience skin rash. None of the other SNPs affected PK or adverse events. The ABCB1 genotype is a potential predictor for erlotinib adverse events. Erlotinib might be used with careful monitoring of adverse events in patients with ABCB1 polymorphic variants.

DiNardo CD, Rausch CR, Benton C, et al.
Clinical experience with the BCL2-inhibitor venetoclax in combination therapy for relapsed and refractory acute myeloid leukemia and related myeloid malignancies.
Am J Hematol. 2018; 93(3):401-407 [PubMed] Related Publications
INTRODUCTION: Venetoclax (VEN), a selective BCL2 inhibitor, has single-agent activity in relapsed and refractory (R/R) acute myeloid leukemia (AML), and efficacy in lower intensity combinations for treatment-naïve elderly AML patients. VEN treatment combinations in R/R AML have not been previously reported.
METHODS: All R/R myeloid patients (including AML, myelodysplastic syndrome (MDS), and blastic plasmacytoid dendritic cell neoplasm (BPDCN)) treated with VEN combinations in the salvage setting were reviewed.
RESULTS: Forty-three patients with median age 68 (range, 25-83) were treated for AML (91%), MDS (5%), or BPDCN (5%). Most (n = 36, 84%) were ≥ salvage-2 treatment status, including prior hypomethylating agent (HMA) in 77%. In combination with VEN, most patients received HMA therapy (n = 31, 72%); eight (19%) received low-dose cytarabine (LDAC). Patients received a median of 2 treatment cycles (range, 1-4). Objective response was observed in 9 (21%) patients, including 2 complete responses (CR), 3 CRi, and 4 morphologic leukemia-free state (MLFS). Median survival was 3.0 months (range, 0.5-8.0), and estimated 6-month survival was 24%. Responses were observed in five (24%) of 21 patients with intermediate-risk cytogenetics, 3 (27%) of 11 IDH1/2-mutant, and 4 (50%) of 8 RUNX1-mutated patients. Two (20%) of 10 TP53-mutated patients responded; both had concurrent RUNX1 mutations. Of the 3 (15%) responding patients with adverse cytogenetics, all had concurrent RUNX1 mutations.
CONCLUSION: Low-intensity chemotherapy, including HMAs or LDAC, in combination with VEN is a viable salvage option, even in multiply relapsed/refractory patients with AML, MDS, and BPDCN. Notable responses were identified in patients with diploid/intermediate cytogenetics, RUNX1, and/or IDH1/2 mutations.

Cliff J, Jorgensen AL, Lord R, et al.
The molecular genetics of chemotherapy-induced peripheral neuropathy: A systematic review and meta-analysis.
Crit Rev Oncol Hematol. 2017; 120:127-140 [PubMed] Related Publications
Chemotherapy-induced peripheral neuropathy (CIPN) can adversely affect completion of systemic anti-cancer treatment and cause long-term morbidity. Increasingly pharmacogenetic studies have been performed to explore susceptibility to this important adverse effect. A systematic review was conducted to identify pharmacogenetic studies, assess their quality and findings and undertake meta-analysis where possible. 93 studies were included. Notable methodological issues included lack of standardisation and detail in phenotype definition and acknowledgement of potential confounding factors. Insufficient data was presented in many studies meaning only a minority could be included in meta-analysis showing mainly non-significant effects. Nonetheless, SNPs in CYP2C8, CYP3A4, ARHGEF10, EPHA and TUBB2A genes (taxanes), FARS2, ACYP2 and TAC1 (oxaliplatin), and CEP75 and CYP3A5 (vincristine) are of potential interest. These require exploration in large cohort studies with robust methodology and well-defined phenotypes. Seeking standardisation of phenotype, collaboration and subsequently, individual-patient-data meta-analysis may facilitate identifying contributory SNPs which could be combined in a polygenic risk score to predict those most at risk of CIPN.

Skiles JL, Chiang C, Li CH, et al.
CYP3A5 genotype and its impact on vincristine pharmacokinetics and development of neuropathy in Kenyan children with cancer.
Pediatr Blood Cancer. 2018; 65(3) [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Vincristine (VCR) is a critical part of treatment in pediatric malignancies and is associated with dose-dependent peripheral neuropathy (vincristine-induced peripheral neuropathy [VIPN]). Our previous findings show VCR metabolism is regulated by the CYP3A5 gene. Individuals who are low CYP3A5 expressers metabolize VCR slower and experience more severe VIPN as compared to high expressers. Preliminary observations suggest that Caucasians experience more severe VIPN as compared to nonCaucasians.
PROCEDURE: Kenyan children with cancer who were undergoing treatment including VCR were recruited for a prospective cohort study. Patients received IV VCR 2 mg/m
RESULTS: The majority of subjects (91%) were CYP3A5 high-expresser genotype. CYP3A5 low-expresser genotype subjects had a significantly higher dose and body surface area normalized area under the curve than CYP3A5 high-expresser genotype subjects (0.28 ± 0.15 hr·m
CONCLUSION: Genetic factors are associated with VCR PK. Due to the minimal neuropathy observed in this cohort, there was no demonstrable association between genetic factors or VCR PK with development of VIPN. Further studies are needed to determine the role of genetic factors in optimizing dosing of VCR for maximal benefit.

Ashida R, Okamura Y, Ohshima K, et al.
Cancer Genomics Proteomics. 2017 Nov-Dec; 14(6):445-453 [PubMed] Free Access to Full Article Related Publications
BACKGROUND/AIM: Project HOPE (High-tech Omics-based Patient Evaluation) began in 2014 using integrated gene expression profiling (GEP) of cancer tissues as well as diathesis of each patient who underwent operation at our Institution. The aim of this study was to identify novel genes displaying altered gene expression related to the survival and early recurrence after hepatectomy for hepatocellular carcinoma (HCC) using the results of integrated GEP analysis.
MATERIALS AND METHODS: The present study included 92 patients. Genes with aberrant expression were selected by the difference of expression levels with ≥10-fold change between tumor and non-tumor tissues.
RESULTS: GEP analysis showed that down-regulation was frequently observed in the PRSS8 (64%), CYP3A4 (61%) and EPCAM (57%) genes. Multivariate analysis revealed tumor stage ≥II (p=0.008) and down-regulation of the CYP3A4 gene (p=0.036) as independent predictor for overall survival. Furthermore, multivariate analysis identified maximum tumor diameter ≥74mm (p=0.008), presence of intrahepatic-metastasis (p=0.020), and down-regulation of CYP3A4 gene (p=0.019) as independent predictors for early recurrence.
CONCLUSION: CYP3A4 was identified as a novel tumor suppressor gene related to a poor prognosis in HCC.

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