Weinshilboum, R. M.

BACKGROUND Because acute exercise increases systemic catecholamines, we sought to determine whether exercise training would alter daily or exercise-related catecholamine release and inactivation. METHODS AND RESULTS In 24-hour urine collections, catecholamines and metabolites provided indexes of overall oxidative deamination, sulfation, and O-methylation. Plasma catecholamines, the sulfoconjugates of each, and chromogranin-A were determined at rest and during exercise in 10 well-trained male subjects and nine minimally trained male subjects (maximal oxygen uptake 55.2 and 42.5 ml/kg/min, respectively), and levels of activities of catechol-O-methyltransferase (COMT), monoamine oxidase B (MAO-B), and thermolabile phenolsulfotransferase (TL-PST) were also determined. Plasma-free catecholamines showed minimal differences between the two groups at submaximal exercise (4 minutes) but large differences at maximal exercise, reflecting the different exercise levels attained. Inactivation of plasma catecholamines by sulfation across rest and exercise tended to be greater in the well-trained group, with small increases in both plasma sulfoconjugated dopamine and sulfoconjugated norepinephrine. In the well-trained group, urinary metabolites demonstrated trends toward increased dopamine release (p less than 0.07) and small increases in the daily release of epinephrine and its sulfoconjugated metabolites. Indexes of deamination, sulfoconjugation, and O-methylation, with the exception of a reduced deamination of dopamine and the activities of COMT, MAO-B, and TL-PST were not different in the two groups. CONCLUSIONS Despite considerable differences in the exercise activities per week between well-trained and minimally trained individuals, there were minimal differences in the release and metabolism of catecholamines at rest or during exercise.

Abstract Background: NSABP P1 and P2 are the largest prevention trials of tamoxifen and raloxifene in women at high risk of developing breast cancer. Both agents have been shown to decrease, but not eliminate breast cancer risk in these women. The goal of our study was to identify single nucleotide polymorphisms (SNPs) associated with development of breast cancer in high-risk women treated with tamoxifen or raloxifene. Methods: We performed a nested matched case-control genome-wide association study (GWAS) in subjects entered on the P2, which included only postmenopausal women, and subjects at least 50 years old entered on the P1 phase III prevention trials who were treated with tamoxifen or raloxifene. Cases were defined as subjects who developed invasive breast cancer or ductal carcinoma in situ and each was matched to two controls based on trial (P1, P2), age at trial entry, Gail risk score, history of lobular carcinoma in situ, and time on study. The study was restricted to the 94% of subjects self-identified as Caucasian. Genotyping was performed with the Illumina Human610-Quad chip. Eigenstrat analyses were performed to control for population stratification. SNPs were imputed within 200 Kb on either side of regions containing SNPs with p ≤ 3E-05. CYP2D6 genotyping was performed on all subjects. Results: The GWAS included 592 cases and 1171 controls. 547,356 SNPs were used in the analyses after removing 14,019 for call rates less than 98%, 30,560 for minor allele frequencies <1%, and 301 with Hardy-Weinberg equilibrium p-value <1E-06. Eigenvectors did not alter the results when used as covariates. Eleven genotyped SNPs with p-values ranging from 2.12E-06 to 9.98E-06 (conditional logistic regression with eigenvector adjustment) were identified; and 22 SNPs with p < 4E-05 were identified by imputation around these SNPs on chromosomes (Chr) 4, 8, 9, 13, 16 and 22, which were then genotyped with the Invader platform. Following imputation and genotyping, initial functional genomic studies have focused on 8 SNPs on Chr 16 (p-values 1.81E-06 to 9.55E-06, with the lowest p-value for an imputed and fine mapped SNP), all of which were in ZNF423, a gene known to encode a protein that associates with SMAD family members. In lymphoblastoid cell lines genotyped for the 2 top SNPs in ZNF423 (rs8060157 and rs11076499) and stably transfected with estrogen receptor-α, the variant and wild type SNPs displayed striking differences in estradiol-induced expression of ZNF423, SMAD3, BRCA1, and BRCA2. Conclusions: This GWAS revealed SNPs associated with the development of breast cancer in high-risk women treated with tamoxifen or raloxifene. Genome-wide significance was not achieved, but SNPs in ZNF423 identified on Chr 16 were associated with differential expression of ZNF423, SMAD3, BRCA1, and BRCA2 in response to estradiol in vitro, providing direction for future research. (Supported in part by NIH grants U01GM61388, U01GM63173, P50CA116201, U10CA77202, U10CA37377, U10CA69974, U24CA114732, and the Biobank Japan Project funded by the Ministry of Education, Culture, Sports, Science and Technology, Japan) Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr PD05-02.

Abstract Abstract #6037 Background: Tamoxifen (Tam) is biotransformed to the potent antiestrogen, endoxifen, by the CYP2D6 enzyme. We previously demonstrated that patients (pts) receiving adjuvant TAM with impaired CYP2D6 metabolism due to CYP2D6 (*4) and/or concurrent administration of a CYP2D6 inhibitor had a higher risk of recurrence. Other studies suggest CYP2C19*17 (Schroth JCO 2007) and SULT1A1*2 (Nowell JNCI 2002) may be associated with treatment outcome. With extended follow-up, we sought to evaluate the importance of comprehensive CYP2D6 genotyping as well as the potential association between CYP2C19*17 and SULT1A1 copy number with clinical outcome in pts randomized to TAM in NCCTG 89-30-52.
 Methods: Using DNA derived from paraffin embedded sections, CYP2D6 and SULT1A1 genotype were determined using quantitative multiplex PCR and CYP2C19 by sequencing. Pts administered the following CYP2D6 inhibitors (fluoxetine, paroxetine, sertraline, cimetidine, amiodarone, doxepin, ticlopidine and haloperidol) were considered as intermediate (IM) or poor metabolizers (PM) based on the potency of CYP2D6 inhibition. CYP2D6 phenotype was defined as follows: extensive metabolizers (EM) were pts not administered an inhibitor who did not carry a null allele (*3, *4, *6) and who were not homozygous for an IM allele (*10, *17, *41). CYP2D6 IM were either heterozygous for a null allele or homozygous for an IM allele but not administered an inhibitor or CYP2D6 EM administered a weak inhibitor. PM were pts homozygous for a null allele, or any patient administered a potent inhibitor. The association between genotype or CYP2D6 phenotype and clinical outcome was determined using the log-rank test. Multivariate Cox modeling was performed using traditional prognostic factors.
 Results: The median follow-up of living pts is now 14.5 years. Of 256 pts. randomized to TAM, genotype was determined for CYP2D6 (n=210), CYP2C19*17 (n=170), and SULT1A1 (n=169) with the following allele frequencies: CYP2D6 *3 (.02), *4(.20), *6 (.01), *10 (.03), *17 (.00), *41(.08), and CYP2C19*17 (.22). The frequency of SULT1A1 copy number alleles (CNA) was 1 (4%), 2 (67%), 3 (20%), and 4+ (9%). 14/227 patients (6%) were administered an inhibitor. A multivariate analysis accounting for nodal status and tumor size demonstrated that compared to CYP2D6 EM, CYP2D6 PM had significantly shorter time to recurrence (TTR) (HR 4.0, p=0.001) and DFS (HR 2.0, p=0.02) and CYP2D6 IM tended to have shorter TTR (HR 1.8, p=0.08) and DFS (HR 1.4, p=0.10). DFS did not differ by SULT1A1 copy number (p=0.62) or CYP2C19 *17 (p=0.47)
 Conclusion: Long term follow-up of pts in NCCTG 89-30-52 confirms the importance of CYP2D6 metabolism and further demonstrates the importance of comprehensive genotyping and phenotyping with CYP2D6 inhibitors. We could not identify an association between CYP2C19*17 or SULT1A1 copy number with recurrence but further evaluation is needed in larger cohorts. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6037.

Clinical Pharmacology & Therapeutics (2003) 73, P29–P29; doi: