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Int J Clin Exp Pathol 2(5),463-475;2009

Original Article
Estrogen Regulates Vesicle Trafficking Gene Expression in EFF-3, EFM-19 and MCF-7
Breast Cancer Cells

Paul K. Wright, Felicity EB May, Steve Darby, Rehan Saif, Tom WJ Lennard and Bruce R Westley

Northern Institute for Cancer Research and School of Surgical and Reproductive Sciences, Medical School, Newcastle University, Framlington
Place, Newcastle upon Tyne, NE2 4HH, UK

Received 16 December 2008; Accepted 26 January 2009; Available online 30 January 2009

Abstract: Estrogens are critical mediators of breast tumorigenesis. This occurs via the action of estrogens on the estrogen receptor (ER),
which regulates the transcriptome of breast cancer cells. Despite the long history of the search for estrogen-regulated genes in breast cancer,
knowledge of the E2-regulated transcriptome and its effects is incomplete. We used Affymetrix GeneChips to profile the effects of estradiol on
the expression of genes in EFF-3, EFM-19 and MCF-7 cells. In addition to many well-characterized estrogen-regulated genes, this identified a
novel group of genes that have roles in vesicle trafficking, including exocytosis. Recent evidence in the literature supports a role for vesicle
trafficking in tumorigenesis. We focused on five genes (SYTL5, RAB27B, SNX24, GALNT4 and SLC12A2/NKCC1/BSC2) and confirmed their
estrogen-regulation using quantitative real-time PCR (qPCR). qPCR also demonstrated that these five genes were expressed in invasive
breast carcinoma tissue. Immunohistochemistry showed expression of SYTL5 in cells of normal breast ductal epithelium, ductal carcinoma
in-situ (DCIS) and invasive breast carcinoma. The results suggest that a significant effect of estrogens is to regulate the expression of genes
that affect diverse aspects of vesicle trafficking including exocytosis. (IJCEP812004).

Key Words: Breast cancer, vesicle, estrogen, synaptotagmin-like protein, RAB GTPase, exocytosis

Full text PDF, supplemental table 1

Address all correspondence to: Drs. Paul K. Wright, MB, ChB, BSc, MRCSEd, PhD or Felicity EB May, School of Surgical and Reproductive
Sciences, 3rd Floor, Leech Building, Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK. Tel:
0191-222-7067; Fax: 0191-222-8514; Email:
paulkwright1@gmail.com