Role of G protein-coupled receptor 1 in choriocarcinoma progression.

Choriocarcinoma is characterized by malignant proliferation and transformation of trophoblasts and is currently treated with systemic chemotherapeutic agents. The lack of specific targets for chemotherapeutic agents results in indiscriminate drug distribution. In our study, we aimed to delineate the mechanism by which G protein-coupled receptor 1 (GPR1) regulates the development of choriocarcinoma and thus investigated GPR1 as a prospective chemotherapeutic target. In this study, GPR1 expression levels were examined in several trophoblast cell lines. We found significantly higher GPR1 expression in choriocarcinoma cells (JEG3 and BeWo) than in normal trophoblast cells (HTR-8/SVneo). Additionally, we studied the role of GPR1 in choriocarcinoma in vitro and in vivo. GPR1 knockdown suppressed proliferation, invasion, and Akt and ERK phosphorylation in vitro and slowed tumor growth in vivo. Interestingly, GPR1 overexpression promoted increased proliferation, invasion, and Akt and ERK phosphorylation in vitro. Furthermore, we identified a specific GPR1-binding seven-amino acid peptide, LRH7-G3, that might also suppress choriocarcinoma in vitro and in vivo through phage display. Our study is the first to report that GPR1 may play a role in regulating choriocarcinoma progression through the Akt and ERK pathways. GPR1 could be a promising potential pharmaceutical target for choriocarcinoma.