Placenta-specific protein 9 (PLAC9)

Placenta-specific protein 9 (PLAC9) is a novel, secreted protein most abundantly expressed in the placenta, with additional roles in embryonic development, particularly in liver and airway epithelial cells[1][3][4]. It is localized to the cytoplasm and secreted via the classical endoplasmic reticulum–Golgi pathway[1][3]. PLAC9 negatively regulates cell proliferation by inducing cell cycle arrest at G2/M or S phase, through modulation of cell cycle proteins, including cyclin B1, cdc2, c-Myc, and p21^Waf/Cip1^[2][3][4]. In cancer biology, especially lung adenocarcinoma, PLAC9 expression is diminished, suggesting a protective role against tumorigenesis via its effects on cell proliferation and motility[2]. Current research focuses on its function in cell growth and differentiation; however, further investigation is necessary to define its molecular partners and therapeutic potential[1][2][3][4].

Other names

Placenta associated 9PLAC9placenta-specific protein 9placenta specific 9

no drugs currently target this protein, but mechanistically, overexpression causes cell cycle arrest through regulation of cyclin/CDK pathways