Effect of FGF2 on the activity of SPRYs/DUSP6/ERK signaling pathway in endometrial glandular epithelial cells of endometriosis.

OBJECTIVE: We aimed at exploring the positive feedback loop in eutopic and ectopic endometrial glandular epithelial cells (EuECs and EECs) in endometriosis. MATERIALS AND METHODS: Normal epithelial cells (NECs), EuECs and EECs were treated with fibroblast growth factor (FGF)2, FGF2 neutralizing antibody, mitogen-activated protein kinases (MAPKs) inhibitors U0126 and PD98059. FGF2 protein level was detected by enzyme-linked immunosorbent assay (ELISA). The expressions of FGF2, FGF receptor 1 (FGFR1), extracellular signal-regulated kinase (ERK)1/2/pERK1/2 and Sproutys (SPRYs) (Sprouty1, Sprouty2, Sprouty4) and dual specificity phosphatase 6 (DUSP6) were detected by Western blot. The mRNA levels of FGF2, FGFR1 (FGF receptor 1), SPRYs (Sprouty1, Sprouty2, Sprouty4) and DUSP6 mRNA were detected by RT-PCR. RESULTS: Among treatment groups, the content of FGF2 in EuECs and EECs was significantly higher than that in NECs (p < 0.05). The mRNA and protein levels of FGF2, FGFR1, SPRYs (Sprouty1, Sprouty2, Sprouty4) and DUSP6 in EuECs and EECs were increased after adding FGF2 (p 0.05). The inhibitory effect of PD9805 on NECs was not significantly different from that of U0126 (p > 0.05); however, the inhibitory effects of PD9805 on EuECs and EECs were significantly lower than those of U0126 (p< 0.05). CONCLUSIONS: The positive feedback loop existed in EuECs and EECs, but maybe not in NECs. The results may provide the guideline to treat endometriosis patients.