Transcription factor ZIC2 regulates tumorigenic phenotypes in epithelial ovarian cancer in a context-dependent manner
Transcription factor ZIC2 plays a pro-tumorigenic role in several human cancers. Herein, we demonstrate that elevated ZIC2 expression was associated with lower overall and post-progression survival of epithelial ovarian cancer (EOC) patients. Knockout of ZIC2 in EOC cells attenuated tumorigenic phenotypes in vitro and in vivo, indicating a pro-tumorigenic role for ZIC2 in EOC. On the other hand, however, overexpression of ZIC2 in EOC cells that do not express endogenous ZIC2 promoted cell migration and sphere formation, but inhibited cell growth and colony formation in vitro and tumor growth in vivo, indicating a context-dependent function for ZIC2 in EOC. Transcriptomic study showed that ZIC2-regulated genes were involved in multiple biological processes and signaling pathways associated with tumor progression and that ZIC2 regulated common or distinct genes in ZIC2 knockout and overexpression models, which explains the consistency and discrepancy in ZIC2 functions observed in the two models. In conclusion, our findings reveal a context-dependent role for ZIC2 in regulating tumorigenic phenotypes in EOC, providing evidence that ZIC2 can be a potential therapeutic target for EOCs that express a high level of ZIC2. Overall design: Gene expression profiling analysis of RNA-seq data for SKOV3 ZIC2 WT, SKOV3 ZIC2 KO, OVCAR3 EV, and OVCAR3 ZIC2 OE