KAT6A, a novel regulator of β-catenin, promotes tumorigenicity and chemoresistance in ovarian cancer by acetylating COP1

Theranostics. 2021 Apr 15;11(13):6278-6292. doi: 10.7150/thno.57455. eCollection 2021.

Abstract

Background: Ovarian cancer is a fatal gynecologic malignancy that is found worldwide and exhibits an insidious onset and a lack of early warning symptoms. Despite ongoing studies, the mechanistic basis of the aggressive phenotypes of ovarian cancer remains unclear. Lysine acetyltransferase 6A (KAT6A) is a MYST-type histone acetyltransferase (HAT) enzyme identified as an oncogene in breast cancer, glioblastoma and leukemia. However, the specific functions of KAT6A in ovarian cancer remain unclear. Methods: Immunohistochemistry (IHC) staining and western blotting were performed to characterize KAT6A protein expression in ovarian cancer tissues and cell lines. The biological functions of KAT6A in ovarian cancer were evaluated by cell proliferation, wound healing and transwell invasion assays in vitro. Tumorigenesis and metastasis assays were performed in nude mice to detect the role of KAT6A in vivo. Mass spectrometry and immunoprecipitation assays were performed to detect the KAT6A-COP1 interaction. An in vivo ubiquitination assay was performed to determine the regulation of β-catenin by KAT6A. Results: In the present study, we revealed that KAT6A expression is upregulated in ovarian cancer and is associated with patient overall survival. Downregulation of KAT6A markedly inhibited the proliferation and migration abilities of ovarian cancer cells in vivo and in vitro. Additionally, the inhibition of KAT6A induced apoptosis and enhanced the sensitivity of ovarian cancer cells to cisplatin. Furthermore, KAT6A bound to and acetylated COP1 at K294. The acetylation of COP1 impaired COP1 function as an E3 ubiquitin ligase and led to the accumulation and enhanced activity of β-catenin. Conclusions: Our findings suggest that the KAT6A/COP1/β-catenin signaling axis plays a critical role in ovarian cancer progression and that targeting the KAT6A/COP1/β-catenin signaling axis could be a novel strategy for treating ovarian cancer.

Keywords: COP1; KAT6A; acetylation; ovarian cancer; β-catenin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylation
  • Animals
  • Antineoplastic Agents, Alkylating / therapeutic use
  • Apoptosis
  • Cell Line, Tumor
  • Cell Transformation, Neoplastic
  • Cisplatin / therapeutic use
  • Disease Progression
  • Drug Resistance, Neoplasm
  • Female
  • Gene Expression Regulation, Enzymologic
  • Gene Expression Regulation, Neoplastic
  • Gene Knockout Techniques
  • Heterografts
  • Histone Acetyltransferases / antagonists & inhibitors
  • Histone Acetyltransferases / genetics
  • Histone Acetyltransferases / physiology*
  • Humans
  • Mice
  • Mice, Nude
  • Neoplasm Proteins / antagonists & inhibitors
  • Neoplasm Proteins / genetics
  • Neoplasm Proteins / physiology*
  • Ovarian Neoplasms / drug therapy
  • Ovarian Neoplasms / metabolism*
  • Prognosis
  • Protein Interaction Mapping
  • Protein Processing, Post-Translational
  • Signal Transduction
  • Tumor Stem Cell Assay
  • Ubiquitin-Protein Ligases / antagonists & inhibitors
  • Ubiquitin-Protein Ligases / metabolism*
  • Ubiquitination
  • beta Catenin / metabolism

Substances

  • Antineoplastic Agents, Alkylating
  • CTNNB1 protein, human
  • Neoplasm Proteins
  • beta Catenin
  • Histone Acetyltransferases
  • KAT6A protein, human
  • COP1 protein, human
  • Ubiquitin-Protein Ligases
  • Cisplatin