DEAD-Box Helicase 4 (Ddx4)⁺ Stem Cells Sustain Tumor Progression in Non-Serous Ovarian Cancers

• Main Authors: Stella D’Oronzo, Erica Silvestris, Domenica Lovero, Paola Cafforio, Loren Duda, Gennaro Cormio, Angelo Paradiso, Raffaele Palmirotta, Franco Silvestris
• Format: Article
• Language: English
• Published: MDPI AG 2020-08-01
• Series: International Journal of Molecular Sciences
• Subjects: Ddx4; follicle-stimulating hormone; non-serous epithelial ovarian cancer, gene expression; next-generation sequencing
• Online Access: https://www.mdpi.com/1422-0067/21/17/6096

DEAD-Box Helicase 4 (Ddx4)⁺ ovarian stem cells are able to differentiate into several cell types under appropriate stimuli. Ddx4 expression has been correlated with poor prognosis of serous ovarian cancer (OC), while the potential role of Ddx4⁺ cells in non-serous epithelial OC (NS-EOC) is almost unexplored. The aim of this study was to demonstrate the presence of Ddx4⁺ cells in NS-EOC and investigate the effect of follicle-stimulating hormone (FSH) on this population. Increased Ddx4 expression was demonstrated in samples from patients with advanced NS-EOC, compared to those with early-stage disease. Under FSH stimulation, OC-derived Ddx4⁺ cells differentiated into mesenchymal-like (ML) cells, able to deregulate genes involved in cell migration, invasiveness, stemness and chemoresistance in A2780 OC cells. This effect was primarily induced by ML-cells deriving from advanced NS-EOC, suggesting that a tumor-conditioned germ cell niche inhabits its microenvironment and is able to modulate, in a paracrine manner, tumor cell behavior through transcriptome modulation.