miR-29c contribute to glioma cells temozolomide sensitivity by targeting O6-methylguanine-DNA methyltransferases indirectely

Oncotarget. 2016 Aug 2;7(31):50229-50238. doi: 10.18632/oncotarget.10357.

Abstract

Temozolomide (TMZ) is the most commonly used alkylating agent in glioma chemotherapy. However growing resistance to TMZ remains a major challenge to clinicians. The DNA repair protein O6-methylguanine-DNA methytransferase (MGMT) plays critical roles in TMZ resistance. Promoter methylation can inhibit MGMT expression and increase chemosensitivity. Here, we described a novel mechanism regulating MGMT expression. We showed that miR-29c suppressed MGMT expression indirectly via targeting specificity protein 1 (Sp1). MiR-29c overexpression increased TMZ efficacy in cultured glioma cells and in mouse xenograft models. The miR-29c levels were positively correlated with patient outcomes. Our data suggest miR-29c may be potential therapeutic targets for glioma treatment.

Keywords: MGMT; TMZ; chemoresistance; glioblastoma; miR-29c.

MeSH terms

  • Alkylating Agents / pharmacology
  • Animals
  • Brain Neoplasms / metabolism
  • Cell Line, Tumor
  • Cell Survival
  • DNA Repair
  • Dacarbazine / analogs & derivatives*
  • Dacarbazine / pharmacology
  • Drug Resistance, Neoplasm*
  • Drug Synergism
  • Glioma / drug therapy*
  • Glioma / metabolism*
  • Humans
  • Mice
  • MicroRNAs / metabolism*
  • Neoplasm Transplantation
  • O(6)-Methylguanine-DNA Methyltransferase / antagonists & inhibitors*
  • O(6)-Methylguanine-DNA Methyltransferase / metabolism
  • Sp1 Transcription Factor / metabolism
  • Temozolomide
  • Treatment Outcome

Substances

  • Alkylating Agents
  • MIRN29a microRNA, human
  • MicroRNAs
  • Sp1 Transcription Factor
  • SP1 protein, human
  • Dacarbazine
  • O(6)-Methylguanine-DNA Methyltransferase
  • Temozolomide