SPAG9 May Be a Potential Prognostic Marker of Endometrial Hyperplasia and Grade 1 Endometrioid Adenocarcinoma Treated with Progestin

Abstract

Background: Sperm-associated antigen 9 (SPAG9), a recently characterized oncogene, may serve as a marker for the early diagnosis of endometrial cancer. However, whether SPAG9 can be a prognostic marker of complex atypical endometrial hyperplasia (CAEH) or grade 1 endometrioid adenocarcinoma (EA) treated with progestin is still unknown. Methods: Progestin therapy was performed in 27 women diagnosed with CAEH (19/27, CAEH group) or grade 1 EA (8/27, EA group). The expression of SPAG9 was measured in pre and post progestin-treated endometrial specimens by immunohistochemistry. The expression of SPAG9 was also examined by real-time polymerase chain reaction (PCR) and Western blot in Ishikawa cells and ECC-1 cells with or without progestin treatment. Results: (1) CAEH showed a significantly better therapeutic efficacy than EA. (2) The expression of SPAG9 was lower in CAEH than in EA. (3) SPAG9 expression significantly declined in the endometrial tissues of women responding to progestin. (4) Significant downregulations of SPAG9 were validated by reverse transcription PCR (RT-PCR) and Western blot both in Ishikawa cells and ECC-1 cells treated with progestin. Conclusion: SPAG9 may be associated with the efficacy of progestin treatment in CAEH and grade 1 EA. It may help to distinguish CAEH from grade 1 EA and serve as a new prognostic marker of CAEH or grade 1 EA treated with progestin.