Physical Poster + E-Poster Presentation 34th Lorne Cancer Conference 2022

Disabled-2 (DAB2), a novel target of Hyaluronan (HA) signalling in ovarian cancerĀ  (#222)

Zoe Price 1 , Noor Lokman 1 , Mai Sugiyama 2 , Yoshihiro Koya 2 , Masato Yoshihara 2 , Hiroki Kajiyama 2 , Carmela Ricciardelli 1 , Martin Oehler 3
  1. University of Adelaide, Adelaide, SA, Australia
  2. Nagoya University, Nagoya, Japan
  3. Department of Gynaecological Oncology, Royal Adelaide Hospital, Adelaide, SA, Australia

A sugar molecule, hyaluronan (HA) promotes growth, invasion and therapy resistance in ovarian cancer cells. HA has been shown to promote and maintain cancer stem cell (CSC) populations in a range of cancers. The Notch3 signaling pathway also promotes and maintains CSC populations and is associated with poor prognosis in ovarian cancer patients. For this study, we determined the effects of different molecular weight HA on ovarian cancer cells overexpressing notch3 intracellular domain (NICD3). NICD3 overexpression enhanced spheroid expression of ES-2 cells. We assessed the effects of different molecular weight HA in spheroids containing ES-2-Lv-NICD3 cells combined with normal ES-2 cells at a ratio of 3:1. 1000kDa HA significantly enhanced spheroid formation. We analysed protein expression in the spheroids using mass spectrometry and identified a protein of interest, disabled homolog 2 (DAB2) enhanced by 1000kDa HA. DAB2 expression is associated with poor outcome in patients with late stage serous ovarian cancer (KmPlot.org database). DAB2 expression was significantly enhanced in ovarian cancer patient tissues at relapse compared to diagnosis. We assessed correlation between expression of DAB2 and epithelial to mesenchymal (EMT) or stem cell associated genes in cell lines from cancers commonly treated with carboplatin using the CellMiner database. DAB2 expression was positively correlated with ZEB2, CHD2, FN1, TGFB1, ZEB1, HAS2, VIM, CTNNB1 and CD44 expression and negatively correlated with CDH1. Interestingly, ZEB2 expression was also increased 10.4 fold (p-value = 0.02) in 1000kDa treated ES-2:ES-2-Lv-NICD3 (1:3) combination spheroids. In HGSOC tissues DAB2 protein and gene expression is highly positively correlated with VIM, CD44, FN1 and TGFB1 (cBioportal, TGCA, n=174-551). We have identified DAB2 as a potential target of 1000kDa HA signaling and EMT regulation.