ABSTRACT
BACKGROUND: Paracrine signaling of the hepatocyte growth factor (HGF) cytokine plays an important role in survival and invasion ability of placental trophoblasts. However, the intracellular factors and biological pathways underlying these responses remain unclear. METHODS: This study investigated whether HGF affected the expression of homeobox gene HLX1, which is principally expressed in reproductive tissues and in some immune cells, and evaluated the implications of such in the HGF-induced human trophoblast cell line HTR-8/SVneo. RESULTS: HGF was found to up-regulate both HLX1 mRNA and protein levels. Transient transfection of small interfering RNA (siRNA) targeting HLX1 abrogated its induction by HGF. Functionally, HLX1 siRNA not only reduced the growth and invasion capacities of HTR-8/SVneo cells at the basal level, but also inhibited these responses induced by HGF treatment. CONCLUSIONS: HLX1 is an essential downstream signaling component of HGF that leads to growth and invasiveness of trophoblast cells.