title: MicroRNA-26a regulates glucose metabolism by direct targeting PDHX in colorectal cancer cells.
abstract: BACKGROUND
  Reprogramming energy metabolism has been an emerging hallmark of cancer cells. MicroRNAs play important roles in glucose metabolism.
  
  
  METHODS
  The targets of microRNA-26a (miR-26a) were predicted by bioinformatics tools. The efficacy of miR-26a binding the 3'-untranslated region (UTR) of pyruvate dehydrogenase protein X component (PDHX) mRNA was evaluated using a dual-luciferase reporter assay. The PDHX expression at the mRNA and protein level in several colon cancer cell lines was quantified with real-time PCR and Western blot analysis respectively. The effects of miR-26a on glucose metabolism were determined by detecting the content of glucose consumption, production of lactate, pyruvate, and acetyl-coenzyme A.
  
  
  RESULTS
  The expression of miR-26a is inversely associated with the level of its targeting protein PDHX in several colon cancer cell lines with different malignancy potentials. MiR-26a inhibits PDHX expression by direct targeting the 3'-UTR of PDHX mRNA. The glucose consumption and lactate concentration were both greatly increased in colon cancer cells than the normal colon mucosal epithelia under physiological conditions. The overexpression of miR-26a in HCT116 cells efficiently improved the accumulation of pyruvate and decreased the production of acetyl coenzyme A. Meanwhile the inhibition of miR-26a expression induced inverse biological effects.
  
  
  CONCLUSIONS
  MiR-26a regulates glucose metabolism of colorectal cancer cells by direct targeting the PDHX, which inhibits the conversion of pyruvate to acetyl coenzyme A in the citric acid cycle.
authors.forename: Bing
authors.initials: B
authors.lastname: Chen
authors.forename: Yuling
authors.initials: Y
authors.lastname: Liu
authors.forename: Xuewen
authors.initials: X
authors.lastname: Jin
authors.forename: Weiliang
authors.initials: W
authors.lastname: Lu
authors.forename: Jingjing
authors.initials: J
authors.lastname: Liu
authors.forename: Zijing
authors.initials: Z
authors.lastname: Xia
authors.forename: Qiong
authors.initials: Q
authors.lastname: Yuan
authors.forename: Xia
authors.initials: X
authors.lastname: Zhao
authors.forename: Ningzhi
authors.initials: N
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Biotherapy/Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, No,17, the third section of Renmin South Road, Chengdu 610041, P, R, China. zizi2006@scu.edu.cn.
authors.forename: Shufang
authors.initials: S
authors.lastname: Liang
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D045744:Cell Line, Tumor; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000378:metabolism*; D019295:Computational Biology; D015972:Gene Expression Regulation, Neoplastic; D005947:Glucose / Q000378:metabolism*; D045325:HCT116 Cells; D006801:Humans; D019344:Lactic Acid / Q000096:biosynthesis; D035683:MicroRNAs / Q000737:chemistry / Q000235:genetics*; D011768:Pyruvate Dehydrogenase Complex / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics
chemical_list: D005947:Glucose; D019344:Lactic Acid; D035683:MicroRNAs; D011768:Pyruvate Dehydrogenase Complex; D012333:RNA, Messenger; C528163:MIRN26 microRNA, human; C045867:PDHX protein, human