Estrogen regulation of phosphoserine phosphatase during regression and recrudescence of female reproductive organs

Phosphoserine phosphatase (PSPH) is a well-known mediator of l-serine biosynthesis in a variety of tissues and its dysregulation causes various diseases, specifically most cancers. However, little is known about the expression and hormonal regulation of PSPH gene in the female reproductive tract. Therefore, in the current study, we focused on relationships between PSPH expression and estrogen during growth, development, differentiation, remodeling and recrudescence of the chicken oviduct and in the progression of epithelial-derived ovarian carcinogenesis in laying hens. The results revealed that PSPH mRNA and protein levels increased in the glandular (GE) and luminal epithelial (LE) cells in the developing oviduct of chicks treated with exogenous estrogen. Additionally, PSPH mRNA and protein expression was up-regulated in GE and LE of the oviduct in response to endogenous estrogen during the recrudescence phase after induced molting. Furthermore, PSPH mRNA and protein were predominantly detected in GE of cancerous, but not normal ovaries. In conclusion, PSPH is a novel estrogen-responsive gene involved in development of the oviduct of chicks and recrudescence of the oviduct of laying hens after molting. PSPH is also a potential target molecule that may help elucidate mechanism responsible for the progression of epithelial cell-derived ovarian carcinogenesis and be of use in therapeutic applications as a biomarker for early diagnosis of epithelial cell-derived ovarian cancer in laying hen as well as women.