title: Molecular mechanism of G1arrest and cellular senescence induced by LEE011, a novel CDK4/CDK6 inhibitor, in leukemia cells.
abstract: BACKGROUND
  Overexpression of cyclin D1 dependent kinases 4 and 6 (CDK4/6) is a common feature of many human cancers including leukemia. LEE011 is a novel inhibitor of both CDK4 and 6. To date, the molecular function of LEE011 in leukemia remains unclear.
  
  
  METHODS
  Leukemia cell growth and apoptosis following LEE011 treatment was assessed through CCK-8 and annexin V/propidium iodide staining assays. Cell senescence was assessed by β-galactosidase staining and p16INK4aexpression analysis. Gene expression profiles of LEE011 treated HL-60 cells were investigated using an Arraystar Human LncRNA array. Gene ontology and KEGG pathway analysis were then used to analyze the differentially expressed genes from the cluster analysis.
  
  
  RESULTS
  Our studies demonstrated that LEE011 inhibited proliferation of leukemia cells and could induce apoptosis. Hoechst 33,342 staining analysis showed DNA fragmentation and distortion of nuclear structures following LEE011 treatment. Cell cycle analysis showed LEE011 significantly induced cell cycle G1arrest in seven of eight acute leukemia cells lines, the exception being THP-1 cells. β-Galactosidase staining analysis and p16INK4aexpression analysis showed that LEE011 treatment can induce cell senescence of leukemia cells. LncRNA microarray analysis showed 2083 differentially expressed mRNAs and 3224 differentially expressed lncRNAs in LEE011-treated HL-60 cells compared with controls. Molecular function analysis showed that LEE011 induced senescence in leukemia cells partially through downregulation of the transcriptional expression of MYBL2.
  
  
  CONCLUSIONS
  We demonstrate for the first time that LEE011 treatment results in inhibition of cell proliferation and induction of G1arrest and cellular senescence in leukemia cells. LncRNA microarray analysis showed differentially expressed mRNAs and lncRNAs in LEE011-treated HL-60 cells and we demonstrated that LEE011 induces cellular senescence partially through downregulation of the expression of MYBL2. These results may open new lines of investigation regarding the molecular mechanism of LEE011 induced cellular senescence.
authors.affiliation: Institute of Pediatrics, Children's Hospital of Soochow University, Suzhou, China.
authors.forename: Yan-Fang
authors.initials: YF
authors.lastname: Tao
authors.affiliation: Department of Hematology and Oncology, Children's Hospital of Soochow University, Suzhou, China.
authors.forename: Na-Na
authors.initials: NN
authors.lastname: Wang
authors.affiliation: Institute of Pediatrics, Children's Hospital of Soochow University, Suzhou, China.
authors.forename: Li-Xiao
authors.initials: LX
authors.lastname: Xu
authors.affiliation: Institute of Pediatrics, Children's Hospital of Soochow University, Suzhou, China.
authors.forename: Zhi-Heng
authors.initials: ZH
authors.lastname: Li
authors.affiliation: Institute of Pediatrics, Children's Hospital of Soochow University, Suzhou, China.
authors.forename: Xiao-Lu
authors.initials: XL
authors.lastname: Li
authors.affiliation: Institute of Pediatrics, Children's Hospital of Soochow University, Suzhou, China.
authors.forename: Yun-Yun
authors.initials: YY
authors.lastname: Xu
authors.affiliation: Institute of Pediatrics, Children's Hospital of Soochow University, Suzhou, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Fang
authors.affiliation: Institute of Pediatrics, Children's Hospital of Soochow University, Suzhou, China.
authors.forename: Mei
authors.initials: M
authors.lastname: Li
authors.affiliation: Institute of Pediatrics, Children's Hospital of Soochow University, Suzhou, China.
authors.forename: Guang-Hui
authors.initials: GH
authors.lastname: Qian
authors.affiliation: Institute of Pediatrics, Children's Hospital of Soochow University, Suzhou, China.
authors.forename: Yan-Hong
authors.initials: YH
authors.lastname: Li
authors.affiliation: Institute of Pediatrics, Children's Hospital of Soochow University, Suzhou, China.
authors.forename: Yi-Ping
authors.initials: YP
authors.lastname: Li
authors.affiliation: Institute of Pediatrics, Children's Hospital of Soochow University, Suzhou, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Department of Hematology and Oncology, Children's Hospital of Soochow University, Suzhou, China.
authors.forename: Jun-Li
authors.initials: JL
authors.lastname: Ren
authors.affiliation: Department of Hematology and Oncology, Children's Hospital of Soochow University, Suzhou, China.
authors.forename: Wei-Wei
authors.initials: WW
authors.lastname: Du
authors.affiliation: Department of Hematology and Oncology, Children's Hospital of Soochow University, Suzhou, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Lu
authors.affiliation: Institute of Pediatrics, Children's Hospital of Soochow University, Suzhou, China.
authors.forename: Xing
authors.initials: X
authors.lastname: Feng
authors.affiliation: Institute of Pediatrics, Children's Hospital of Soochow University, Suzhou, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.affiliation: CAM-SU Genomic Resource Center, Soochow University, Suzhou, China.
authors.forename: Wei-Qi
authors.initials: WQ
authors.lastname: He
authors.affiliation: Department of Hematology and Oncology, Children's Hospital of Soochow University, Suzhou, China.
authors.forename: Shao-Yan
authors.initials: SY
authors.lastname: Hu
authors.affiliation: Institute of Pediatrics, Children's Hospital of Soochow University, Suzhou, China.
authors.forename: Jian
authors.identifier: 0000-0002-0292-5141
authors.initials: J
authors.lastname: Pan
keywords: Arraystar Human LncRNA array; CDK4/6; Cellular senescence; LEE011; Leukemia