Role of epidermal growth factor in pathogenesis of uterine leiomyomas

Objective:To investigate the role of epidermal growth factor(EGF) in the pathogenesis of uterine leiomyomas.Methods:Human myometrial smooth muscle cells(HM-SMCs) and smooth muscle cells of human uterine leiomyomas(HL-SMCs) were separated from patients' specimens and cultured.After processed by EGF or PD98059(inhibitor of MKK/MEK) +EGF,the proliferation rate of both SMCs was detected by BrdU method and the phosphorylation level of p44/42 mitogen-activated protein kinase(MAPK) was determined by Western-blot.After different processing time by EGF,the phosphorylation levels of p44/42 MAPK and AKT and p27 expression level in both SMCs were detected by Western-blot.Results:EGF could significantly promote HL-SMCs proliferation and PD98059 could inhibit this effect(P<0.05);besides,PD98059 could inhibit the increase of the phosphorylation level of p44/42 MAPK in both SMCs induced by EGF.When the processing time by EGF was over 15 min,the phosphorylation levels of p44/42 MAPK and AKT in both SMCs decreased sharply and were close to zero:p27 expression in HM-SMCs raised significantly while the upregulation in HL-SMCs was little.Conclusions:EGF could not cause activation of EGFR because of the dephosphorylation of p44/42 MAPK and AKT in HL-SMCs,which caused p27 expression insufficiently and cell cycle dysregulation.