title: ADA3 regulates normal and tumor mammary epithelial cell proliferation through c-MYC.
abstract: We have established the critical role of ADA3 as a coactivator of estrogen receptor (ER), as well as its role in cell cycle progression. Furthermore, we showed that ADA3 is predominantly nuclear in mammary epithelium, and in ER+, but is cytoplasmic in ER- breast cancers, the latter correlating with poor survival. However, the role of nuclear ADA3 in human mammary epithelial cells (hMECs), and in ER+ breast cancer cells, as well as the importance of ADA3 expression in relation to patient prognosis and survival in ER+ breast cancer have remained uncharacterized.
  
  
  
  We overexpressed ADA3 in hMECs or in ER+ breast cancer cells and assessed the effect on cell proliferation. The expression of ADA3 was analyzed then correlated with the expression of various prognostic markers, as well as survival of breast cancer patients.
  
  
  
  Overexpression of ADA3 in ER- hMECs as well as in ER+ breast cancer cell lines enhanced cell proliferation. These cells showed increased cyclin B and c-MYC, decreased p27 and increased SKP2 levels. This was accompanied by increased mRNA levels of early response genes c-FOS, EGR1, and c-MYC. Analysis of breast cancer tissue specimens showed a significant correlation of ADA3 nuclear expression with c-MYC expression. Furthermore, nuclear ADA3 and c-MYC expression together showed significant correlation with tumor grade, mitosis, pleomorphism, NPI, ER/PR status, Ki67 and p27 expression. Importantly, within ER+ cases, expression of nuclear ADA3 and c-MYC also significantly correlated with Ki67 and p27 expression. Univariate Kaplan Meier analysis of four groups in the whole, as well as the ER+ patients showed that c-MYC and ADA3 combinatorial phenotypes showed significantly different breast cancer specific survival with c-MYC-high and ADA3-Low subgroup had the worst outcome. Using multivariate analyses within the whole cohort and the ER+ subgroups, the significant association of ADA3 and c-MYC expression with patients' outcome was independent of tumor grade, stage and size, and ER status.
  
  
  
  ADA3 overexpression enhances cell proliferation that is associated with increased expression of c-MYC. Expression patterns with respect to ADA3/c-MYC can divide patients into four significantly different subgroups, with c-MYC High and ADA3 Low status independently predicting poor survival in patients.
authors.affiliation: Departments of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, 985805 Nebraska Medical Center, Omaha, NE, 68198, USA.
authors.forename: Nicolas I
authors.initials: NI
authors.lastname: Griffin
authors.affiliation: Departments of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, 985805 Nebraska Medical Center, Omaha, NE, 68198, USA.
authors.forename: Gayatri
authors.initials: G
authors.lastname: Sharma
authors.affiliation: Departments of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, 985805 Nebraska Medical Center, Omaha, NE, 68198, USA.
authors.forename: Xiangshan
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Departments of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, 985805 Nebraska Medical Center, Omaha, NE, 68198, USA.
authors.forename: Sameer
authors.initials: S
authors.lastname: Mirza
authors.affiliation: Departments of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, 985805 Nebraska Medical Center, Omaha, NE, 68198, USA.
authors.forename: Shashank
authors.initials: S
authors.lastname: Srivastava
authors.affiliation: Departments of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, 985805 Nebraska Medical Center, Omaha, NE, 68198, USA.|Departments of Human Genetics Laboratories, Munroe Meyer Institute for Genetics and Rehabilitation, University of Nebraska Medical Center, 985805 Nebraska Medical Center, Omaha, NE, 68198, USA.|Departments of Pathology & Microbiology, College of Medicine, University of Nebraska Medical Center, 985805 Nebraska Medical Center, Omaha, NE, 68198, USA.
authors.forename: Bhavana J
authors.initials: BJ
authors.lastname: Dave
authors.affiliation: School of Molecular Medical Sciences and Cellular Pathology, University of Nottingham and Nottingham University Hospital, Nottingham City Hospital, Hucknall Road, Nottingham, NG5 1PB, USA.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Aleskandarany
authors.affiliation: School of Molecular Medical Sciences and Cellular Pathology, University of Nottingham and Nottingham University Hospital, Nottingham City Hospital, Hucknall Road, Nottingham, NG5 1PB, USA.
authors.forename: Emad
authors.initials: E
authors.lastname: Rakha
authors.affiliation: Departments of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, 985805 Nebraska Medical Center, Omaha, NE, 68198, USA.
authors.forename: Shakur
authors.initials: S
authors.lastname: Mohibi
authors.affiliation: Departments of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, 985805 Nebraska Medical Center, Omaha, NE, 68198, USA.|Departments of Pathology & Microbiology, College of Medicine, University of Nebraska Medical Center, 985805 Nebraska Medical Center, Omaha, NE, 68198, USA.|Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, 985805 Nebraska Medical Center, Omaha, NE, 68198, USA.|Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, 985805 Nebraska Medical Center, Omaha, NE, 68198, USA.
authors.forename: Hamid
authors.initials: H
authors.lastname: Band
authors.affiliation: Departments of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, 985805 Nebraska Medical Center, Omaha, NE, 68198, USA. vband@unmc.edu.|Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, 985805 Nebraska Medical Center, Omaha, NE, 68198, USA. vband@unmc.edu.
authors.forename: Vimla
authors.initials: V
authors.lastname: Band
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D014408:Biomarkers, Tumor; D001940:Breast / Q000378:metabolism*; D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D002453:Cell Cycle / Q000235:genetics; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D002461:Cell Line, Transformed; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics; D049109:Cell Proliferation; D050760:Cyclin-Dependent Kinase Inhibitor p27 / Q000378:metabolism; D004195:Disease Models, Animal; D004847:Epithelial Cells / Q000378:metabolism*; D005260:Female; D015870:Gene Expression; D015972:Gene Expression Regulation, Neoplastic; D055785:Gene Knockdown Techniques; D016259:Genes, myc; D064593:Heterografts; D006801:Humans; D053208:Kaplan-Meier Estimate; D059785:Karyotype; D051379:Mice; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D010641:Phenotype; D011379:Prognosis; D016016:Proportional Hazards Models; D012307:Risk Factors; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism*; D047368:Tumor Burden
chemical_list: D014408:Biomarkers, Tumor; D018797:Cell Cycle Proteins; C444103:TADA3 protein, human; D014157:Transcription Factors; D050760:Cyclin-Dependent Kinase Inhibitor p27
keywords: ADA3; breast cancer; c.-MYC; cell cycle; proliferation