RCC2 promotes proliferation and radio-resistance in glioblastoma via activating transcription of DNMT1

Biochem Biophys Res Commun. 2019 Aug 27;516(3):999-1006. doi: 10.1016/j.bbrc.2019.06.097. Epub 2019 Jul 2.

Abstract

Regulator of chromosome condensation 2 (RCC2) is a regulator of cell-cycle progression linked in multiple cancers to pro-tumorigenic phenomena including promotion of tumor growth, tumor metastases and poorer patient prognoses. However, the role of RCC2 in GBM remains under-investigated. Here, we sought to determine the relevance of RCC2 in GBM, as well as its roles in GBM development, progression and prognosis. Initial clinical evaluation determined significant RCC2 enrichment in GBM when compared to normal brain tissue, and elevated expression was closely associated with a poorer prognosis in glioma patients. Via shRNA inhibition, we determined that RCC2 is essential to tumor proliferation and tumorigenicity in vitro and in vivo. Additionally, RCC2 was determined to promote radioresistance of GBM tumor cells. Investigation of the underlying mechanisms implicated DNA mismatch repair, JAK-STAT pathway and activated transcription of DNA methyltransferase 1 (DNMT1). For validation, pharmacologic inhibition via administration of a DNMT1 inhibitor demonstrated attenuated GBM tumor growth both in vitro and in vivo. Collectively, this study determined a novel therapeutic target for GBM in the form of RCC2, which plays a pivotal role in GBM proliferation and radio-resistance via regulation of DNMT1 expression in a p-STAT3 dependent manner.

Keywords: DNMT1; Glioblastoma; RCC2; Radio-resistance; Tumorigenesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brain Neoplasms / genetics*
  • Brain Neoplasms / mortality
  • Brain Neoplasms / pathology
  • Brain Neoplasms / therapy
  • Carcinogenesis / genetics
  • Carcinogenesis / metabolism
  • Carcinogenesis / pathology
  • Cell Line, Tumor
  • Cell Proliferation / radiation effects
  • Chromosomal Proteins, Non-Histone / antagonists & inhibitors
  • Chromosomal Proteins, Non-Histone / genetics*
  • Chromosomal Proteins, Non-Histone / metabolism
  • DNA (Cytosine-5-)-Methyltransferase 1 / antagonists & inhibitors
  • DNA (Cytosine-5-)-Methyltransferase 1 / genetics*
  • DNA (Cytosine-5-)-Methyltransferase 1 / metabolism
  • Decitabine / pharmacology
  • Disease Progression
  • Enzyme Inhibitors / pharmacology
  • Gene Expression Regulation, Neoplastic*
  • Glioblastoma / genetics*
  • Glioblastoma / mortality
  • Glioblastoma / pathology
  • Glioblastoma / therapy
  • Guanine Nucleotide Exchange Factors / antagonists & inhibitors
  • Guanine Nucleotide Exchange Factors / genetics*
  • Guanine Nucleotide Exchange Factors / metabolism
  • Heterografts
  • Humans
  • Janus Kinase 1 / genetics
  • Janus Kinase 1 / metabolism
  • Mice
  • Mice, SCID
  • Neoplasm Grading
  • Neuroglia / metabolism
  • Neuroglia / pathology
  • Neuroglia / radiation effects
  • Prognosis
  • RNA, Small Interfering / genetics
  • RNA, Small Interfering / metabolism
  • Radiation Tolerance / genetics*
  • STAT Transcription Factors / genetics
  • STAT Transcription Factors / metabolism
  • Signal Transduction
  • Survival Analysis
  • Transcription, Genetic

Substances

  • Chromosomal Proteins, Non-Histone
  • Enzyme Inhibitors
  • Guanine Nucleotide Exchange Factors
  • RCC2 protein, human
  • RNA, Small Interfering
  • STAT Transcription Factors
  • Decitabine
  • DNA (Cytosine-5-)-Methyltransferase 1
  • DNMT1 protein, human
  • JAK1 protein, human
  • Janus Kinase 1