title: Long non-coding RNA DBCCR1-003 regulate the expression of DBCCR1 via DNMT1 in bladder cancer.
abstract: BACKGROUND
  Many long non coding RNAs have been identified as key modulators in cancer development. A lncRNA, DBCCR1-003, derived from the locus of tumor suppressor gene DBCCR1 (deleted in bladder cancer chromosome region 1), has unknown function. In the present study, we explored function and molecular mechanism of DBCCR1-003 in bladder cancer (BC) development.
  
  
  METHODS
  We evaluated the expression levels of DBCCR1-003 in tissues and cells with western blot and quantitative real-time polymerase chain reaction. Multiple approaches including chromatin immunoprecipitation assay and RNA immunoprecipitation were used to confirm the direct binding of DBCCR1-003 to DNMT1. The recombinant vector overexpressing DBCCR1-003 was constructed. Cell proliferation assay, colony formation assay and flow cytometric analysis were employed to measure the role of DBCCR1-003 in regulation of cell proliferation, cycle and apoptosis.
  
  
  RESULTS
  Firstly we detected the expression of DBCCR1-003, DBCCR1, DNMT1 (DNA methyltransferase 1) and DNA methylation in the promoter of DBCCR1. We found low expression of DBCCR1-003, same as DBCCR1, while high expression of DNMT1 and hypermethylation of DBCCR1 gene promoter in BC tissues and T24 cells line. Further studies revealed that treatment of DNMT inhibitor, 5-aza-2-deoxycytidine(DAC), or overexpression of DBCCR1-003 led to increased DBCCR1 expression by reversion of promoter hypermethylation and DNMT1 binding to DBCCR1 promoter in T24 cells. Importantly, RNA immunoprecipitation (RIP) showed that DBCCR1-003 physically associates with DNMT1. The binding of them was increased with the inhibition of DBCCR1 promoter methylation, indicating that DBCCR1-003 may bind to DNMT1 and prevent DNMT1-mediated the methylation of DBCCR1. Furthermore, overexpression of DBCCR1-003 resulted in significant inhibition of T24 cells growth through the inducing G0/G1 arrest and apoptosis.
  
  
  CONCLUSIONS
  Taken together, these findings demonstrated that a novel tumor suppressor DBCCR1-003 regulates the expression of DBCCR1 via binding to DNMT1 and preventing DNMT1-mediated the methylation of DBCCR1 in BC. LncRNA DBCCR1-003 may serve as a novel biomarker and therapeutic target for BC in future cancer clinic.
authors: Guangdong Key Laboratory of Urology, Department of Urology, Minimally Invasive Surgery Center, The First Affiliated Hospital of Guangzhou Medical University, Kangda Road 1#, Haizhu District, Guangzhou, 510230 Guangdong China.
authors: Defeng
authors: D
authors: Qi
authors: Guangdong Key Laboratory of Urology, Department of Urology, Minimally Invasive Surgery Center, The First Affiliated Hospital of Guangzhou Medical University, Kangda Road 1#, Haizhu District, Guangzhou, 510230 Guangdong China.|The Affiliated Hospital of School of Medicine of Ningbo University, Zhejiang, 315000 China.
authors: Jinhui
authors: J
authors: Li
authors: Guangdong Key Laboratory of Urology, Department of Urology, Minimally Invasive Surgery Center, The First Affiliated Hospital of Guangzhou Medical University, Kangda Road 1#, Haizhu District, Guangzhou, 510230 Guangdong China.
authors: Biao
authors: B
authors: Que
authors: Guangdong Key Laboratory of Urology, Department of Urology, Minimally Invasive Surgery Center, The First Affiliated Hospital of Guangzhou Medical University, Kangda Road 1#, Haizhu District, Guangzhou, 510230 Guangdong China.|The First Affiliated Hospital, Center for Translational Medicine, Sun Yat-sen University, Guangzhou, 510080 China.
authors: Jialin
authors: J
authors: Su
authors: Guangdong Key Laboratory of Urology, Department of Urology, Minimally Invasive Surgery Center, The First Affiliated Hospital of Guangzhou Medical University, Kangda Road 1#, Haizhu District, Guangzhou, 510230 Guangdong China.
authors: Mengxi
authors: M
authors: Li
authors: Guangdong Key Laboratory of Urology, Department of Urology, Minimally Invasive Surgery Center, The First Affiliated Hospital of Guangzhou Medical University, Kangda Road 1#, Haizhu District, Guangzhou, 510230 Guangdong China.
authors: Chaofeng
authors: C
authors: Zhang
authors: Breast Disease Center, Guangdong Women and Children Hospital of Guangzhou Medical University, Guangzhou, 510010 Guangdong China.|Department of General Surgery, General Hospital of Guangzhou Military Command of PLA, Guangzhou, 510010 Guangdong China.
authors: Mei
authors: M
authors: Yang
authors: Department of Medical Oncology, Jiangsu Cancer Hospital, Nanjing, 210009 Jiangsu China.
authors: Guoren
authors: G
authors: Zhou
authors: The First Affiliated Hospital, Center for Translational Medicine, Sun Yat-sen University, Guangzhou, 510080 China.
authors: Weidong
authors: W
authors: Ji
keywords: Bladder cancer; DBCCR1; DBCCR1-003; DNMT1; lncRNA