Forkhead box transcription factor, forkhead box A 1, shows negative association with lymph node status in endometrial cancer, and represses cell proliferation and migration of endometrial cancer cells

Endometrial cancer is the most common malignancy of the female genital tract and is associated with poor prognosis. It is primarily a hormone‐dependent cancer that is regulated by steroid hormones, including estrogen and progesterone. Forkhead box A 1 ( FOXA 1) is a member of the forkhead box transcription factor family and functions as a pioneer factor in estrogen receptor ( ER )‐positive breast cancer. In the present study, we investigated the expression of FOXA 1 in endometrial cancers by immunohistochemical analysis. Nuclear immunoreactivity for FOXA 1 was detected in 40 of 109 cases (37%), and was found to be negatively associated with lymph node status ( P  = 0.033). In ER ‐positive I shikawa endometrial cancer cells, small interfering RNA ‐mediated downregulation of FOXA 1 promoted cell proliferation and migration. Furthermore, exogenously introduced FOXA 1 suppressed both proliferation and migration of I shikawa cells. These results suggest that FOXA 1 functions as a tumor suppressor through modulation of proliferation and migration of endometrial cancer cells. ( Cancer Sci 2012; 103: 806–812)