Background: Despite the recent research implicating E2F8 (E2F Transcription Factor 8) in cancer, the role of E2F8 in the progression of ovarian cancer has remained unclear. Hence, we explored the bio-functional effects of E2F8 knockdown on ovarian cancer cell lines in vitro and in vivo. Methods: The expression of E2F8 was compared between ovarian cancer and noncancer tissues, and its association with the progression-free survival of ovarian cancer patients was analyzed. To demonstrate the function of E2F8 in cell proliferation, migration, and invasion, we employed RNA interference to suppress E2F8 expression in ovarian cancer cell lines. Finally, the effect of E2F8 knockdown was investigated in a xenograft mouse model of ovarian cancer. Results: Ovarian cancer tissue exhibited significantly higher E2F8 expression compared to that of normal ovarian tissue. Clinical data showed that E2F8 was a significant predictor of progression-free survival. Moreover, the prognosis of the ovarian cancer patients with high E2F8 expression was poorer than that of the patients with low E2F8 expression. In vitro experiments using E2F8-knockdown ovarian cancer cell lines demonstrated that E2F8 knockdown inhibited cell proliferation, migration, and tumor invasion. Additionally, E2F8 was a potent inducer and modulator of the expression of epithelial–mesenchymal transition and Notch signaling pathway-related markers. We confirmed the function of E2F8 in vivo, signifying that E2F8 knockdown was significantly correlated with reduced tumor size and weight. Conclusions: Our findings indicate that E2F8 is highly correlated with ovarian cancer progression. Hence, E2F8 can be utilized as a prognostic marker and therapeutic target against ovarian malignancy.

Head and neck squamous cell carcinomas (HNSCC) affect more than 800,000 people annually worldwide, causing over 15,000 deaths in the US. Among HNSCC cancers, human papillomavirus (HPV)-negative HNSCC has the worst outcome, motivating efforts to improve therapy for this disease. The most common mutational events in HPV-negative HNSCC are inactivation of the tumor suppressors TP53 (>85%) and CDKN2A (>57%), which significantly impairs G1/S checkpoints, causing reliance on other cell cycle checkpoints to repair ongoing replication damage. We evaluated a panel of cell cycle-targeting clinical agents in a group of HNSCC cell lines to identify a subset of drugs with single-agent activity in reducing cell viability. Subsequent analyses demonstrated potent combination activity between the CHK1/2 inhibitor LY2606268 (prexasertib), which eliminates a G2 checkpoint, and the WEE1 inhibitor AZD1775 (adavosertib), which promotes M-phase entry, in induction of DNA damage, mitotic catastrophe, and apoptosis, and reduction of anchorage independent growth and clonogenic capacity. These phenotypes were accompanied by more significantly reduced activation of CHK1 and its paralog CHK2, and enhanced CDK1 activation, eliminating breaks on the mitotic entry of cells with DNA damage. These data suggest the potential value of dual inhibition of CHK1 and WEE1 in tumors with compromised G1/S checkpoints.

Cell cycle profiles of Fadu parental and AfaR cell models after 1, 3, or 5 days treatment with VIC-1911

Signaling consequences in Fadu parental, AfaR, or ErlR cells of treatment with VIC-1911 alone or in combination with erlotinib or afatinib

Signaling consequences in Cal27 parental, AfaR, or ErlR cells of treatment with VIC-1911 alone or in combination with erlotinib or afatinib

Characterization of baselines and biological response to AURKA inhibition in parental, AfaR, and ErlR HNSCC cell lines.