AKR1C3 Overexpression Mediates Methotrexate Resistance in Choriocarcinoma Cells

Background: Chemotherapy is typically used to treat choriocarcinoma, but a small proportion of tumors develop resistance to chemotherapy. Similarly, methotrexate (MTX) is a first-line chemotherapy used to treat choriocarcinoma; although ~30% of patients are drug-resistant for MTX mono-therapy. Thus, we sought to elucidate the mechanism of chemotherapeutic-resistance of MTX. Methods: RNA interference technology, colony formation, and MTT assays were used to investigate the role of aldo-keto reductase family 1, member C3 (AKR1C3) in MTX resistance in choriocarcinoma cells. Results: AKR1C3 expression was higher in JeG-3R cells compared to JeG-3 cells and targeted inhibition of AKR1C3 expression with shRNA suppresses growth of choriocarcinoma cells as measured by colony formation and MTT assays. Overexpression of AKR1C3 increased chemotherapeutic resistance in JeG-3 cells. Furthermore, AKR1C3 silencing increases sensitivity to MTX in JeG-3R choriocarcinoma cells. Increasing MTX sensitivity spears to be related to DNA damage induction by increased reactive oxygen species (ROS), apoptosis, and cell cycle arrest. Conclusions: Data show that AKR1C3 is critical to the development of methotrexate resistance in choriocarcinoma and suggest that AKR1C3 may potentially serve as a therapeutic marker for this disease.