title: Dehydroglyasperin D Inhibits the Proliferation of HT-29 Human Colorectal Cancer Cells Through Direct Interaction With Phosphatidylinositol 3-kinase.
abstract: BACKGROUND
  Despite recent advances in therapy, colorectal cancer still has a grim prognosis. Although licorice has been used in East Asian traditional medicine, the molecular properties of its constituents including dehydroglyasperin D (DHGA-D) remain unknown. We sought to evaluate the inhibitory effect of DHGA-D on colorectal cancer cell proliferation and identify the primary signaling molecule targeted by DHGA-D.
  
  
  METHODS
  We evaluated anchorage-dependent and -independent cell growth in HT-29 human colorectal adenocarcinoma cells. The target protein of DHGA-D was identified by Western blot analysis with a specific antibody, and direct interaction between DHGA-D and the target protein was confirmed by kinase and pull-down assays. Cell cycle analysis by flow cytometry and further Western blot analysis was performed to identify the signaling pathway involved.
  
  
  RESULTS
  DHGA-D significantly suppressed anchorage-dependent and -independent HT-29 colorectal cancer cell proliferation. DHGA-D directly suppressed phosphatidylinositol 3-kinase (PI3K) activity and subsequent Akt phosphorylation and bound to the p110 subunit of PI3K. DHGA-D also significantly induced G1 cell cycle arrest, together with the suppression of glycogen synthase kinase 3β and retinoblastoma phosphorylation and cyclin D1 expression.
  
  
  CONCLUSIONS
  DHGA-D has potent anticancer activity and targets PI3K in human colorectal adenocarcinoma HT-29 cells. To our knowledge, this is the first report to detail the molecular basis of DHGA-D in suppressing colorectal cancer cell growth.
authors.affiliation: Research Group of Nutraceuticals for Metabolic Syndrome, Korea Food Research Institute, Seongnam, Keimyung University, Daegu, Korea; Food Biotechnology Program, Korea University of Science and Technology, Daejeon, Keimyung University, Daegu, Korea.
authors.forename: Sung Keun
authors.initials: SK
authors.lastname: Jung
authors.affiliation: College of Pharmacy, Keimyung University, Daegu, Korea.
authors.forename: Chul-Ho
authors.initials: CH
authors.lastname: Jeong
keywords: Cell cycle; Colorectal neoplasms; Dehydroglyasperin D; PI3K; Proliferation