ABSTRACT
AIM: To discuss the effects of phytoestrogenic-genistein on cathepsin K (CK) expression stimulated by interleukin-1α (IL-1α) in osteoclast-like cells (OCLs) . METHODS: The OCLs were isolated from tissue of human giant cell tumor of bone (GCT) . The cells treated with reagents were divided into 7 groups including control (treated with phenol red-free-DMEM), vehicle (treated with 1.2 nmol· L-1 IL- 1α), 10-10-10-6genistein, genistein+ ICI 182.780, and 17[β-estrodiol (17β-E2) group. The cells were treated with 1.2 nmol· L-1IL-1α after pre-treated with genistein or 17β-E2 for 48 h (excluded the control group) . Expression of CK wasdetermined by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot in OCLs stimulated by IL-1α in the presence of genistein or 17[β-E2. RESULTS: The obvious increase of expression of CK by IL1α in vehicle group was noted in comparing with control group (P ＜ 0.01 ) . Genistein down-regulated CK gene expression stimulated by IL-1α at the transcription level in a dose-dependent manner (r = 0.68, P ＜ 0.01 ) .Genistein down-regulated CK protein expression stimulated by IL-1α also in a dose-dependent manner (r = 0.61,P ＜ 0.01 ). The effects of genistein were abrogated partly after treatment with the estrogen receptor antagonist ICI 182.780. CONCLUSION: Genistein inhibits CK expression stimulated by IL-1α partly through estrogen receptor in OCLs.