HNF1β Drives Glutathione (GSH) Synthesis Underlying Intrinsic Carboplatin Resistance of Ovarian Clear Cell Carcinoma (OCCC)

Tumour Biol. 2016 Apr;37(4):4813-29. doi: 10.1007/s13277-015-4290-5. Epub 2015 Oct 31.

Abstract

Chemoresistance to platinum-based antineoplastic agents is a consistent feature among ovarian carcinomas; however, whereas high-grade serous carcinoma (OSC) acquires resistance during chemotherapy, ovarian clear cell carcinoma (OCCC) is intrinsically resistant. The main objective of this study was to explore, in vitro and in vivo, if hepatocyte nuclear factor 1β (HNF1β) and glutaminolysis contribute for the resistance of OCCC to carboplatin through the intrinsically increased GSH bioavailability. To disclose the role of HNF1β, experiments were also performed in an OSC cell line, which does not express HNF1β. Metabolic profiles, GSH quantification, HNF1β, and γ-glutamylcysteine ligase catalytic subunit (GCLC) and modifier subunit (GCLM) expression, cell cycle, and death were assessed in ES2 cell line (OCCC) and OVCAR3 cell line (OSC); HNF1β knockdown was performed in ES2 and murine model of subcutaneous and peritoneal OCCC tumors was established to test buthionine sulphoxamine (BSO), as a sensitizer to carboplatin. Glutaminolysis is activated in ES2 and OVCAR3, though ES2 exclusively synthesizes amino acids and GSH. ES2 cells are more resistant to carboplatin than OVCAR3 and the abrogation of GSH production by BSO sensitizes ES2 to carboplatin. HNF1β regulates the expression of GCLC, but not GCLM, and consequently GSH production in ES2. In vivo, BSO prior to carboplatin reduces dramatically subcutaneous tumor size and GSH levels, as well as peritoneal dissemination. Our study discloses HNF1β as the mediator of intrinsic OCCC chemoresistance and sheds a light to re-explore a cancer adjuvant therapeutic approach using BSO to overcome the lack of efficient therapy in OCCC.

Keywords: Buthionine sulphoxamine (BSO); Chemoresistance to carboplatin; Clear cell carcinoma (OCCC); Glutathione (GSH); Hepatocyte nuclear factor 1β (HNF1β); γ-Glutamylcysteine ligase catalytic and modifier subunits (GCLC/M).

MeSH terms

  • Adenocarcinoma, Clear Cell / drug therapy*
  • Adenocarcinoma, Clear Cell / genetics
  • Adenocarcinoma, Clear Cell / pathology
  • Animals
  • Carboplatin / administration & dosage
  • Cell Line, Tumor
  • Cisplatin / administration & dosage
  • Drug Resistance, Neoplasm / genetics
  • Female
  • Gene Expression Regulation, Neoplastic / drug effects
  • Glutamate-Cysteine Ligase / biosynthesis*
  • Glutamate-Cysteine Ligase / blood*
  • Glutamate-Cysteine Ligase / genetics
  • Glutathione / biosynthesis
  • Hepatocyte Nuclear Factor 1-beta / biosynthesis*
  • Hepatocyte Nuclear Factor 1-beta / genetics
  • Humans
  • Mice
  • Ovarian Neoplasms / drug therapy*
  • Ovarian Neoplasms / genetics
  • Ovarian Neoplasms / pathology
  • Xenograft Model Antitumor Assays

Substances

  • HNF1B protein, human
  • Hepatocyte Nuclear Factor 1-beta
  • Carboplatin
  • GCLC protein, human
  • Glutamate-Cysteine Ligase
  • glutamate-cysteine ligase modifier subunit, human
  • Glutathione
  • Cisplatin