Integrated quantitative analysis of the phosphoproteome and transcriptome in tamoxifen-resistant breast cancer.
Quantitative phosphoproteome and transcriptome analysis of ligand-stimulated MCF-7 human breast cancer cells was performed to understand the mechanisms of tamoxifen resistance at a system level. Phosphoproteome data revealed that WT cells were more enriched with phospho-proteins than tamoxifen-resistant cells after stimulation with ligands. Surprisingly, decreased phosphorylation after ligand perturbation was more common than increased phosphorylation. In particular, 17β-estradiol induced down-regulation in WT cells at a very high rate. 17β-Estradiol and the ErbB ligand heregulin induced almost equal numbers of up-regulated phospho-proteins in WT cells. Pathway and motif activity analyses using transcriptome data additionally suggested that deregulated activation of GSK3β (glycogen-synthase kinase 3β) and MAPK1/3 signaling might be associated with altered activation of cAMP-responsive element-binding protein and AP-1 transcription factors in tamoxifen-resistant cells, and this hypothesis was validated by reporter assays. An examination of clinical samples revealed that inhibitory phosphorylation of GSK3β at serine 9 was significantly lower in tamoxifen-treated breast cancer patients that eventually had relapses, implying that activation of GSK3β may be associated with the tamoxifen-resistant phenotype. Thus, the combined phosphoproteome and transcriptome data set analyses revealed distinct signal transcription programs in tumor cells and provided a novel molecular target to understand tamoxifen resistance.
Medical Proteomics Laboratory, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan. moyama@ims.u-tokyo.ac.jp
Masaaki
M
Oyama
Takeshi
T
Nagashima
Takashi
T
Suzuki
Hiroko
H
Kozuka-Hata
Noriko
N
Yumoto
Yuichi
Y
Shiraishi
Kazuhiro
K
Ikeda
Yoko
Y
Kuroki
Noriko
N
Gotoh
Takanori
T
Ishida
Satoshi
S
Inoue
Hiroaki
H
Kitano
Mariko
M
Okada-Hatakeyama
D001943:Breast Neoplasms / Q000235:genetics* / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D019008:Drug Resistance, Neoplasm / Q000187:drug effects / Q000235:genetics*; D020869:Gene Expression Profiling / Q000379:methods*; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism; D000071679:Glycogen Synthase Kinase 3 beta; D006801:Humans; D008024:Ligands; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D020543:Proteome / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D013629:Tamoxifen / Q000494:pharmacology*; D018808:Transcription Factor AP-1 / Q000378:metabolism; D014158:Transcription, Genetic; D016896:Treatment Outcome
D017362:Cyclic AMP Response Element-Binding Protein; D008024:Ligands; D010750:Phosphoproteins; D020543:Proteome; D018808:Transcription Factor AP-1; D013629:Tamoxifen; C000605506:GSK3B protein, human; D000071679:Glycogen Synthase Kinase 3 beta; D020928:Mitogen-Activated Protein Kinases; D038362:Glycogen Synthase Kinase 3