ONC201 demonstrates anti-tumorigenic and anti-metastatic activity in uterine serous carcinoma in vitro

Uterine serous carcinoma (USC) represents an aggressive histologic subtype of endometrial cancer. It is associated with a poor prognosis, and improved therapies for women battling USCs are greatly needed. ONC201 is an orally bioavailable, first-in-class small molecule that induces tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) independent of p53. ONC201 has demonstrated anti-tumorigenic activity in pre-clinical models of solid tumors through induction of apoptosis and inactivation of the AKT/MAPK pathways. Recent phase I and II clinical trials have shown that ONC201 is well tolerated and may have single agent activity in high grade glioma patients among others. We sought to determine the effects of ONC201 on cell proliferation in USC and identify the mechanisms by which ONC201 inhibits cell growth in this disease. ONC201 inhibited cell proliferation in a dose-dependent manner in ARK1, ARK2 and SPEC-2 cell lines. The anti-proliferative activity of ONC201 in ARK1 and SPEC-2 cells was associated with induction apoptosis independent of p53 via both a TRAIL mediated apoptotic pathway and a mitochondrial apoptosis pathway. Treatment with ONC201 resulted in significant reduction in adhesion and invasion as well as inhibition of the AKT and MAPK pathways. In addition, ONC201 markedly potentiated the anti-tumorigenic effects of paclitaxel in USC cells. Our results suggest that ONC201 has significant anti-proliferative and anti-metastatic effects in USC cells through both induction of apoptosis and inhibition of the AKT and MAPK pathways. ONC201 and paclitaxel are a promising therapeutic combination in USC cells. Thus, ONC201 should be evaluated as a single agent and as a therapeutic partner with paclitaxel in future clinical trials of USC.