Histone Acetyltransferase KAT6A Upregulates PI3K/AKT Signaling through TRIM24 Binding

Cancer Res. 2017 Nov 15;77(22):6190-6201. doi: 10.1158/0008-5472.CAN-17-1388. Epub 2017 Oct 11.

Abstract

Lysine acetyltransferase KAT6A is a chromatin regulator that contributes to histone modification and cancer, but the basis of its actions are not well understood. Here, we identify a KAT6A signaling pathway that facilitates glioblastoma (GBM), where it is upregulated. KAT6A expression was associated with GBM patient survival. KAT6A silencing suppressed cell proliferation, cell migration, colony formation, and tumor development in an orthotopic mouse xenograft model system. Mechanistic investigations demonstrated that KAT6A acetylates lysine 23 of histone H3 (H3K23), which recruits the nuclear receptor binding protein TRIM24 to activate PIK3CA transcription, thereby enhancing PI3K/AKT signaling and tumorigenesis. Overexpressing activated AKT or PIK3CA rescued the growth inhibition due to KAT6A silencing. Conversely, the pan-PI3K inhibitor LY294002 abrogated the growth-promoting effect of KAT6A. Overexpression of KAT6A or TRIM24, but not KAT6A acetyltransferase activity-deficient mutants or TRIM24 mutants lacking H3K23ac-binding sites, promoted PIK3CA expression, AKT phosphorylation, and cell proliferation. Taken together, our results define an essential role of KAT6A in glioma formation, rationalizing its candidacy as a therapeutic target for GBM treatment. Cancer Res; 77(22); 6190-201. ©2017 AACR.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blotting, Western
  • Brain Neoplasms / genetics
  • Brain Neoplasms / metabolism
  • Brain Neoplasms / pathology
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Cell Line, Tumor
  • Cell Proliferation / genetics
  • Gene Expression Regulation, Neoplastic
  • Glioblastoma / genetics
  • Glioblastoma / metabolism
  • Glioblastoma / pathology
  • Histone Acetyltransferases / genetics
  • Histone Acetyltransferases / metabolism*
  • Humans
  • Mice, Nude
  • Phosphatidylinositol 3-Kinases / metabolism*
  • Phosphorylation
  • Protein Binding
  • Proto-Oncogene Proteins c-akt / metabolism*
  • RNA Interference
  • Reverse Transcriptase Polymerase Chain Reaction
  • Signal Transduction*
  • Transplantation, Heterologous

Substances

  • Carrier Proteins
  • TRIM24 protein, human
  • Histone Acetyltransferases
  • KAT6A protein, human
  • Phosphatidylinositol 3-Kinases
  • Proto-Oncogene Proteins c-akt