title: miR-20a mediates temozolomide-resistance in glioblastoma cells via negatively regulating LRIG1 expression.
abstract: Resistance to temozolomide (TMZ) is a major obstacle in the treatment of glioblastoma multiforme (GBM). MiRNAs is considered as an important modulator of drug resistance in many cancers. Here, we aimed to elucidate the relationship between miR-20a, its predicted target genes leucine-rich repeats and immunoglobulin-like domains 1 (LRIG1) and TMZ resistance in GBM.
  
  
  
  Real-time PCR or western blot was used to measure the levels of miR-20a and LRIG1. The cell viability was obtained to investigate the sensitivity of U251 cells and TMZ-resistant U251 (U251/TMZ) cells to TMZ. MiR-20a inhibitor or miR-20a mimic was used to down-regulate or up-regulate miR-20a expression. The interaction between miR-20a and its predicted target gene LRIG1 was confirmed by 3'-UTR dual-luciferase reporter assay. pcDNA-LRIG1 was used to overexpress LRIG1 [corrected]. A xenograft tumor model was used to investigate the in vivo antitumor activity.
  
  
  
  MiR-20a was highly expressed and LRIG1 lowly expressed in U251/TMZ cells. Knockdown of miR-20a by treatment with miR-20a inhibitor restored sensitivity of U251/TM cells to TMZ in vivo and in vitro, whereas overexpression of miR-20a by treatment with miR-20a mimic resulted in increased TMZ resistance. The levels of LRIG1 were inversely related to miR-20a levels. And the luciferase reporter assays showed that miR-20a directly targeted the 3'UTR of LRIG1. In addition, functional knock-down of LRIG1 by gene specific siRNA reversed the effect of miR-20a inhibitor.
  
  
  
  MiR-20a mediated TMZ-resistance in glioblastoma cells through negatively regulating LRIG1 expression, which suggesting that miR-20a and LRIG1 would be potential therapeutic targets for glioma therapy.
authors.affiliation: Department of Intensive Care Unit, Sir Run Run Shaw Hospital, College of Medical Sciences, Zhejiang University, Hangzhou 310016, China.
authors.forename: Junhua
authors.initials: J
authors.lastname: Wei
authors.affiliation: Department of Neurosurgery, Sir Run Run Shaw Hospital, College of Medical Sciences, Zhejiang University, Hangzhou 310016, China.
authors.forename: Xuchen
authors.initials: X
authors.lastname: Qi
authors.affiliation: Department of Reproductive Endocrinology, Women's Hospital, College of Medical Sciences, Zhejiang University, Hangzhou 310006, China.
authors.forename: Qitao
authors.initials: Q
authors.lastname: Zhan
authors.affiliation: Department of Emergency, Sir Run Run Shaw Hospital, College of Medical Sciences, Zhejiang University, Hangzhou 310016, China.
authors.forename: Daoyang
authors.initials: D
authors.lastname: Zhou
authors.affiliation: College of Life Science, Zhejiang University, Hangzhou 310058, China.
authors.forename: Qingfeng
authors.initials: Q
authors.lastname: Yan
authors.affiliation: Department of Neurosurgery, Sir Run Run Shaw Hospital, College of Medical Sciences, Zhejiang University, Hangzhou 310016, China.
authors.forename: Yirong
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Neurosurgery, Sir Run Run Shaw Hospital, College of Medical Sciences, Zhejiang University, Hangzhou 310016, China.
authors.forename: Lianjie
authors.initials: L
authors.lastname: Mo
authors.affiliation: Department of Neurosurgery, Sir Run Run Shaw Hospital, College of Medical Sciences, Zhejiang University, Hangzhou 310016, China.
authors.forename: Yingfeng
authors.initials: Y
authors.lastname: Wan
authors.affiliation: Department of Neurosurgery, Sir Run Run Shaw Hospital, College of Medical Sciences, Zhejiang University, Hangzhou 310016, China.
authors.forename: Dajiang
authors.initials: D
authors.lastname: Xie
authors.affiliation: Department of Neurosurgery, Sir Run Run Shaw Hospital, College of Medical Sciences, Zhejiang University, Hangzhou 310016, China.
authors.forename: Jixi
authors.initials: J
authors.lastname: Xie
authors.affiliation: Department of Neurosurgery, Sir Run Run Shaw Hospital, College of Medical Sciences, Zhejiang University, Hangzhou 310016, China. Electronic address: yang.sx@163.com.
authors.forename: Shuxu
authors.initials: S
authors.lastname: Yang
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D001932:Brain Neoplasms / Q000235:genetics* / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D003606:Dacarbazine / Q000031:analogs & derivatives* / Q000494:pharmacology; D019008:Drug Resistance, Neoplasm / Q000187:drug effects* / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D005909:Glioblastoma / Q000235:genetics* / Q000473:pathology; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics* / Q000378:metabolism; D008819:Mice, Nude; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D000077204:Temozolomide
chemical_list: D000970:Antineoplastic Agents; C484445:LRIG1 protein, human; C534451:MIRN20a microRNA, human; D008562:Membrane Glycoproteins; D035683:MicroRNAs; D003606:Dacarbazine; D000077204:Temozolomide
keywords: Glioblastoma cells; Leucine-rich repeats and immunoglobulin-like domains 1 (LRIG1); Temozolomide; miR-20a