Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0027947 (neutropenia)
 17,527 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Etoposide is a substrate for P-glycoprotein, CYP3A4, CYP3A5, and UGT1A1. Glucocorticoids modulate CYP3A and P-glycoprotein in preclinical models, but their effect on clinical etoposide disposition is unknown. We studied the pharmacokinetics of etoposide and its catechol metabolite in children with acute lymphoblastic leukemia, along with polymorphisms in CYP3A4, CYP3A5, MDR1, GSTP1, UGT1A1, and VDR. Plasma pharmacokinetics were assessed at day 29, after 1 month of prednisone (n = 102), and at week 54, without prednisone (n = 44). On day 29, etoposide clearance was higher (47.4 versus 29.2 mL/min/m2, P <.0001) than at week 54. The day 29 etoposide or catechol area under the curve (AUC) was correlated with neutropenia (P =.027 and P =.0008, respectively). The relationship between genotype and etoposide disposition differed by race and by prednisone use. The MDR1 exon 26 CC genotype predicted higher day 29 etoposide clearance (P =.002) for all patients, and the CYP3A5 AA and GSTP1 AA genotypes predicted lower clearance in blacks (P =.02 and.03, respectively). The UGT1A1 6/6, VDR intron 8 GG, and VDR Fok 1 CC genotypes predicted higher week 54 clearance in blacks (P =.039,.036, and.052, respectively). The UGT1A1 6/6 genotype predicted lower catechol AUC. Prednisone strongly induces etoposide clearance, genetic polymorphisms may predict the constitutive and induced clearance of etoposide, and the relationship between genotype and phenotype differs by race.
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PMID:Effects of prednisone and genetic polymorphisms on etoposide disposition in children with acute lymphoblastic leukemia. 1296 65

Pharmacogenomics has largely been applied to the personalization of irinotecan-based treatment, focusing mainly on the study of genetic variants in adsorption, distribution, metabolism, and excretion (ADME) genes. The transcriptional control of ADME gene expression is mediated by a set of nuclear factors responding to cancer-related inflammation, which could have pharmacological implications. The aim of the present study was to uncover novel genetic predictors of neutropenia and gastrointestinal toxicity risk among 246 haplotype-tagging polymorphisms in 22 genes encoding inflammation-related cytokines and transcriptional regulators of ADME genes. The study comprised overall more than 400 metastatic colorectal cancer (mCRC) patients treated with first-line FOLFIRI, grouped in a discovery and a replication cohorts. A concordant protective effect of STAT-3 rs1053004 polymorphism against the risk of grade 3-4 gastrointestinal toxicity was observed in both the cohorts of patients (OR = 0.51, p = 0.045, q = 0.521 and OR = 0.39, p = 0.043, respectively). VDR rs11574077 polymorphism was demonstrated to affect both irinotecan biliary index (BI) and glucuronidation ratio (GR) by a pharmacokinetic analysis. This effect was consistent with an increased risk of grade 3-4 gastrointestinal toxicity in the discovery cohort (OR = 4.46, p = 0.010, q = 0.305). The association was not significant in the replication cohort (OR = 1.44, p = 0.601). These findings suggest an effect of STAT-3 and VDR polymorphisms on FOLFIRI-related gastrointestinal toxicity. If prospectively validated as predictive markers, they could be used to improve the clinical management of mCRC.
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PMID:Association of STAT-3 rs1053004 and VDR rs11574077 With FOLFIRI-Related Gastrointestinal Toxicity in Metastatic Colorectal Cancer Patients. 2970 92