title: Differential gene expression in tamoxifen-resistant breast cancer cells revealed by a new analytical model of RNA-Seq data.
abstract: Resistance to tamoxifen (Tam), a widely used antagonist of the estrogen receptor (ER), is a common obstacle to successful breast cancer treatment. While adjuvant therapy with Tam has been shown to significantly decrease the rate of disease recurrence and mortality, recurrent disease occurs in one third of patients treated with Tam within 5 years of therapy. A better understanding of gene expression alterations associated with Tam resistance will facilitate circumventing this problem. Using a next generation sequencing approach and a new bioinformatics model, we compared the transcriptomes of Tam-sensitive and Tam-resistant breast cancer cells for identification of genes involved in the development of Tam resistance. We identified differential expression of 1215 mRNA and 513 small RNA transcripts clustered into ERα functions, cell cycle regulation, transcription/translation, and mitochondrial dysfunction. The extent of alterations found at multiple levels of gene regulation highlights the ability of the Tam-resistant cells to modulate global gene expression. Alterations of small nucleolar RNA, oxidative phosphorylation, and proliferation processes in Tam-resistant cells present areas for diagnostic and therapeutic tool development for combating resistance to this anti-estrogen agent.
authors: Department of Pharmacology, The Penn State Cancer Institute, The Pennsylvania State University College of Medicine, Milton S. Hershey Medical Center, Hershey, Pennsylvania, United States of America.
authors: Kathryn J
authors: KJ
authors: Huber-Keener
authors: Xiuping
authors: X
authors: Liu
authors: Zhong
authors: Z
authors: Wang
authors: Yaqun
authors: Y
authors: Wang
authors: Willard
authors: W
authors: Freeman
authors: Song
authors: S
authors: Wu
authors: Maricarmen D
authors: MD
authors: Planas-Silva
authors: Xingcong
authors: X
authors: Ren
authors: Yan
authors: Y
authors: Cheng
authors: Yi
authors: Y
authors: Zhang
authors: Kent
authors: K
authors: Vrana
authors: Chang-Gong
authors: CG
authors: Liu
authors: Jin-Ming
authors: JM
authors: Yang
authors: Rongling
authors: R
authors: Wu
mesh_terms: D001943:Breast Neoplasms / Q000473:pathology*; D017024:Chemotherapy, Adjuvant; D016000:Cluster Analysis; D019295:Computational Biology / Q000379:methods*; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D061986:MCF-7 Cells; D010641:Phenotype; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D022661:RNA, Untranslated / Q000235:genetics; D015203:Reproducibility of Results; D017423:Sequence Analysis, RNA; D013629:Tamoxifen / Q000494:pharmacology*; D059467:Transcriptome / Q000187:drug effects*
chemical_list: D012333:RNA, Messenger; D022661:RNA, Untranslated; D013629:Tamoxifen