RUNX3 Transcript Variants Have Distinct Roles in Ovarian Carcinoma and Differently Influence Platinum Sensitivity and Angiogenesis

  • Cancers (Basel). 2021 Jan 26;13(3):476. doi: 10.3390/cancers13030476.
Karolin Heinze  1 ,  Martin Hölzer  2 ,  Martin Ungelenk  3 ,  Melanie Gerth  3 ,  Jürgen Thomale  4 ,  Regine Heller  5 ,  Claire R Morden  6 ,  Kirk J McManus  6 ,  Alexander S Mosig  7 ,  Matthias Dürst  1 ,  Ingo B Runnebaum  1 ,  Norman Häfner  1
Affiliations
  • 1. Department of Gynecology and Reproduction Medicine, Jena University Hospital, 07747 Jena, Germany.
  • 2. RNA Bioinformatics and High-Throughput Analysis, Faculty of Mathematics and Computer Science, University of Jena, 07743 Jena, Germany.
  • 3. Institute for Human Genetics, Jena University Hospital, 07747 Jena, Germany.
  • 4. Institute for Cell Biology (Cancer Research), Essen University Hospital, 45122 Essen, Germany.
  • 5. Institute for Molecular Cell Biology, Jena University Hospital, 07747 Jena, Germany.
  • 6. Research Institute in Oncology and Hematology, University of Manitoba, Winnipeg, MB R3E 0V9, Canada.
  • 7. Department of Biochemistry II, Jena University Hospital, 07747 Jena, Germany.
PMID: 33530588 DOI: 10.3390/cancers13030476
Abstract

The prognosis of late-stage epithelial ovarian Cancer (EOC) patients is affected by chemotherapy response and the malignant potential of the tumor cells. In earlier work, we identified hypermethylation of the runt-related transcription factor 3 gene (RUNX3) as a prognostic biomarker and contrary functions of transcript variants (TV1 and TV2) in A2780 and SKOV3 cells. The aim of the study was to further validate these results and to increase the knowledge about RUNX3 function in EOC. New RUNX3 overexpression models of high-grade serous ovarian Cancer (HGSOC) were established and analyzed for phenotypic (IC50 determination, migration, proliferation and angiogenesis assay, DNA damage analysis) and transcriptomic consequences (NGS) of RUNX3 TV1 and TV2 overexpression. Platinum sensitivity was affected by a specific transcript variant depending on BRCA background. RUNX3 TV2 induced an increased sensitivity in BRCA1wt cells (OVCAR3), whereas TV1 increased the sensitivity and induced a G2/M arrest under treatment in BRCA1mut cells (A13-2-12). These different phenotypes relate to differences in DNA repair: homologous recombination deficient A13-2-12 cells show less γH2AX foci despite higher levels of Pt-DNA adducts. RNA-Seq analyses prove transcript variant and cell-line-specific RUNX3 effects. Pathway analyses revealed another clinically important function of RUNX3-regulation of angiogenesis. This was confirmed by thrombospondin1 analyses, HUVEC spheroid sprouting assays and proteomic profiling. Importantly, conditioned media (CM) from RUNX3 TV1 overexpressing A13-2-12 cells induced an increased HUVEC sprouting. Altogether, the presented data support the hypothesis of different functions of RUNX3 transcript variants related to the clinically relevant processes-platinum resistance and angiogenesis.

Keywords
RUNX3; angiogenesis; epithelial ovarian cancer; platinum resistance; transcript variants.