title: Expression of Derlin-1 and its effect on expression of autophagy marker genes under endoplasmic reticulum stress in lung cancer cells.
abstract: BACKGROUND
  Recent findings indicated that Derlin-1 has an important function in tumour progression. In this study, we aimed to determine whether Derlin-1 has an oncogene function as a cross-talk molecule with autophagy.
  
  
  METHODS
  Cancer cells were treated with tunicamycin (TM) for 8 and 24 h. The expression of Derlin-1 and autophagy-related genes was determined by western blot. Autophagy was analysed by fluorescence microscopy after staining the cancer cells with monodansylcadaverine. The interaction between Derlin-1 and other proteins was identified using co-immunoprecipitation assay.
  
  
  RESULTS
  Our study demonstrated high Derlin-1 expression levels in most non-small lung cancer cell lines. Derlin-1 expression was enhanced under endoplasmic reticulum (ER) stress. Previous studies revealed that TM triggers the initiation of autophagy by activating Beclin 1, converting LC3I to LC3II and degrading p62. Knockdown of Derlin-1 did not affect Beclin 1 and LC3II expression but disrupted the degradation of p62 under ER stress, which resulted in the blockage of autophagy flux. Furthermore, Derlin-1 and p62 were observed to interact under ER stress.
  
  
  CONCLUSIONS
  This study is the first report about the interaction between Derlin-1 and p62. Derlin-1 may function in tumour progression partially by interacting with p62.
authors.affiliation: Department of Respiratory Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, P.R. China.
authors.forename: Li
authors.initials: L
authors.lastname: Xu
authors.affiliation: Department of Obstetrics and Gynecology, The Shanxi Da Yi Hospital, Taiyuan 030001, P.R. China.
authors.forename: Zan-Hong
authors.initials: ZH
authors.lastname: Wang
authors.affiliation: Center for Disease Control and Prevention, Gaoxin/Xinshi, District of Urumqi, Xinjiang Province, P.R. China.
authors.forename: Dong
authors.initials: D
authors.lastname: Xu
authors.affiliation: Center for Disease Control and Prevention, Gaoxin/Xinshi, District of Urumqi, Xinjiang Province, P.R. China.
authors.forename: Gang
authors.initials: G
authors.lastname: Lin
authors.affiliation: Department of Respiratory Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, P.R. China.
authors.forename: Dai-Rong
authors.initials: DR
authors.lastname: Li
authors.affiliation: Department of Respiratory Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, P.R. China.
authors.forename: Tao
authors.initials: T
authors.lastname: Wan
authors.affiliation: Department of Respiratory Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, P.R. China.
authors.forename: Shu-Liang
authors.initials: SL
authors.lastname: Guo
keywords: Autophagy; Derlin-1; ER stress; p62