title: Overexpression of major CDKN3 transcripts is associated with poor survival in lung adenocarcinoma.
abstract: BACKGROUND
  The cyclin-dependent kinase inhibitor 3 (CDKN3) has been perceived as a tumour suppressor. Paradoxically, CDKN3 is often overexpressed in human cancer. It was unclear if CDKN3 overexpression is linked to alternative splicing variants or mutations that produce dominant-negative CDKN3.
  
  
  METHODS
  We analysed CDKN3 expression and its association with patient survival in three cohorts of lung adenocarcinoma. We also examined CDKN3 mutations in the Cancer Genome Atlas (TCGA) and the Moffitt Cancer Center's Total Cancer Care (TCC) projects. CDKN3 transcripts were further analysed in a panel of cell lines and lung adenocarcinoma tissues. CDKN3 mRNA and protein levels in different cell cycle phases were examined.
  
  
  RESULTS
  CDKN3 is overexpressed in non small cell lung cancer. High CDKN3 expression is associated with poor overall survival in lung adenocarcinoma. Two CDKN3 transcripts were detected in all samples. These CDKN3 transcripts represent the full length CDKN3 mRNA and a normal transcript lacking exon 2, which encodes an out of frame 23-amino acid peptide with little homology to CDKN3. CDKN3 mutations were found to be very rare. CDKN3 mRNA and protein were elevated during the mitosis phase of cell cycle.
  
  
  CONCLUSIONS
  CDKN3 overexpression is prognostic of poor overall survival in lung adenocarcinoma. CDKN3 overexpression in lung adenocarcinoma is not attributed to alternative splicing or mutation but is likely due to increased mitotic activity, arguing against CDKN3 as a tumour suppressor.
authors.affiliation: Department of Molecular Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA.|Department of General Surgery, Tangdu Hospital, the Fourth Military Medical University, Xi'an, 710032 China.
authors.forename: Chao
authors.initials: C
authors.lastname: Fan
authors.affiliation: Department of Molecular Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA.
authors.forename: Lu
authors.initials: L
authors.lastname: Chen
authors.affiliation: Department of Molecular Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA.
authors.forename: Qingling
authors.initials: Q
authors.lastname: Huang
authors.affiliation: Department of Molecular Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA.|Cancer Biology Program, Peggy and Charles Stephenson Cancer Center, University of Oklahoma Health Sciences Center, 975 North East 10th Street, Oklahoma City, OK 73104, USA.|Department of Pathology, University of Oklahoma Health Sciences Center, 975 North East 10th Street, Oklahoma City, OK 73104, USA.
authors.forename: Tao
authors.initials: T
authors.lastname: Shen
authors.affiliation: Department of Biostatistics and Bioinformatics, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA.
authors.forename: Eric A
authors.initials: EA
authors.lastname: Welsh
authors.affiliation: Department of Biostatistics and Bioinformatics, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA.|Department of Oncologic Sciences, University of South Florida College of Medicine, Tampa, FL 33612, USA.
authors.forename: Jamie K
authors.initials: JK
authors.lastname: Teer
authors.affiliation: Department of Chemistry, University of South Florida, Tampa, FL 33612, USA.
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Cai
authors.affiliation: Department of Molecular Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA.|Department of Oncologic Sciences, University of South Florida College of Medicine, Tampa, FL 33612, USA.
authors.forename: W Douglas
authors.initials: WD
authors.lastname: Cress
authors.affiliation: Department of Molecular Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA.|Cancer Biology Program, Peggy and Charles Stephenson Cancer Center, University of Oklahoma Health Sciences Center, 975 North East 10th Street, Oklahoma City, OK 73104, USA.|Department of Pathology, University of Oklahoma Health Sciences Center, 975 North East 10th Street, Oklahoma City, OK 73104, USA.|Department of Oncologic Sciences, University of South Florida College of Medicine, Tampa, FL 33612, USA.
authors.forename: Jie
authors.initials: J
authors.lastname: Wu
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics*; D000595:Amino Acid Sequence; D015331:Cohort Studies; D050756:Cyclin-Dependent Kinase Inhibitor Proteins / Q000737:chemistry / Q000235:genetics*; D054637:Dual-Specificity Phosphatases / Q000737:chemistry / Q000235:genetics*; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics*; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000235:genetics*; D016019:Survival Analysis
chemical_list: D050756:Cyclin-Dependent Kinase Inhibitor Proteins; D012333:RNA, Messenger; C084429:CDKN3 protein, human; D054637:Dual-Specificity Phosphatases