Selective estrogen receptor modulators and pharmacogenomic variation in ZNF423 regulation of BRCA1 expression: individualized breast cancer prevention.

Author(s): Ingle JN,  Liu M,  Wickerham DL,  Schaid DJ,  Wang L,  Mushiroda T,  Kubo M,  Costantino JP,  Vogel VG,  Paik S,  Goetz MP,  Ames MM,  Jenkins GD,  Batzler A,  Carlson EE,  Flockhart DA,  Wolmark N,  Nakamura Y,  Weinshilboum RM

Journal: Cancer Discov

Date: 2013 Jul

Major Program(s) or Research Group(s): COPTRG, NCORP

PubMed ID: 23764426

PMC ID: PMC3710533

Abstract: The selective estrogen receptor modulators (SERM) tamoxifen and raloxifene can reduce the occurrence of breast cancer in high-risk women by 50%, but this U.S. Food and Drug Administration-approved prevention therapy is not often used. We attempted to identify genetic factors that contribute to variation in SERM breast cancer prevention, using DNA from the NSABP P-1 and P-2 breast cancer prevention trials. An initial discovery genome-wide association study identified common single-nucleotide polymorphisms (SNP) in or near the ZNF423 and CTSO genes that were associated with breast cancer risk during SERM therapy. We then showed that both ZNF423 and CTSO participated in the estrogen-dependent induction of BRCA1 expression, in both cases with SNP-dependent variation in induction. ZNF423 appeared to be an estrogen-inducible BRCA1 transcription factor. The OR for differences in breast cancer risk during SERM therapy for subjects homozygous for both protective or both risk alleles for ZNF423 and CTSO was 5.71.