ARG1 is a potential prognostic marker in metastatic and recurrent endometrial cancer.

Endometrial cancer (EC) is the most common gynecologic malignancy. While the majority of patients present with early-stage and low-grade EC and have an excellent prognosis, a subset has metastatic disease at presentation, or develops distant recurrence after initial treatment of the primary. However, the lack of prognostic biomarkers for metastatic EC is a critical barrier. Arginase 1 (ARG1) regulates the last step of the urea cycle, and an increase in ARG1 has been correlated as a poor prognostic factor in a variety of cancers. In the present study, ARG1 expression was evaluated as a potential prognostic marker for metastatic EC in endometrial hyperplasia and cancer of mice with mutation as well as double mutations. While mutation in the uterus is not sufficient for distant metastasis, mice with concurrent ablation of and develop distant metastasis. Our immunostaining and RT-qPCR analysis revealed that the expression of ARG1 in early stage of EC as well as endometrial hyperplasia from mice deficient in and mutations significantly increased compared to mutation in the uterus. The results suggest that a high level of ARG1 is associated with poor prognosis in association with EC of mouse.