4-羟基他莫昔芬对体外培养前列腺平滑肌细胞的作用

目的 研究4-羟基他莫昔芬(OHT)对原代培养的前列腺平滑肌细胞增殖与凋亡以及雌、雄激素受体表达的影响.方法 以不同浓度的雌二醇(E2)、乙烯雌酚(DES)和OHT分别作用于原代培养的前列腺平滑肌细胞,采用流式细胞术检测增殖和凋亡,免疫细胞化学检测雌、雄激素受体表达.结果 DES和E2在一定浓度范围内起促增殖作用(均P<0.05),但未发现明显的浓度相关性(DES:r=-0.101,P=0.328;E2:r=-0.115,P=0.188).OHT浓度在1×10-8moL/L时,前列腺平滑肌细胞增殖率为5.04%±0.65%,随着浓度由1×10-6mol/L升高为1×10-5mol/L,细胞增殖率由2 79%±0 54%下降为0.93%±0.40%.在更高浓度下显示与浓度相关的促凋亡作用(5.83%±0.78%、13.70%±0.71%、19.53%±0.90%),以上作用不能被相同甚至更高浓度的E2所逆转.OHT对雌、雄激素受体表达的影响与雌激素相近.结论 OHT在一定浓度范围内对原代培养的前列腺平滑肌细胞具有明显的抑制增殖和促凋亡作用,且该作用可能不依赖于雌激素受体途径.口服他莫昔芬后OHT血药浓度较低和OHT上调雄激素受体表达可能是他莫昔芬治疗前列腺增生效果不佳的原因.

Effects of 4-hydroxytamoxifen on prostate smooth muscle cells: an in vitro experiment

Objective To investigate the effects of 4- hydroxytamoxifen (OHT) on the proliferation and apoptosis of prostate smooth muscle cells and the expression of estrogen receptor (ER) and androgen receptor (AR). Methods Prostate smooth muscle cells were isolated from the reseeted specimens of prostate glands of 10 patients with benign prostatic hypertrophy (BPH) , cultured, and exposed to estradiol (E2), diethylstilbestrol (DES), and OHT of different concentrations (1 ×10-8 - 1×10-5 mol/L) or mixture of E2(1×10-8 - 1×10-6 tool/L) with OHT (1×10-7 mol/L). Flow eytometry was used to test the proliferation and apoptosis of the cells, and immunoeytochemistry was used to test the expression of estrogen and androgen receptors. Results E2 and DES promoted the proliferation of the prostate smooth muscle cells in a certain concentration range, but not dose-dependently, and OHT at the concentration of 1×10-8 mol/L slightly increased the G2-M peak rate of the prostate smooth muscle cells, but suppressed the G2-M peak rate dose-dependently when its concentration was ≥1×10-7 mol/L (P < 0. 05) and this suppression effect was dose-dependently (r = - 0. 312, P = 0. 011). E2 at the concentration ≥1×10-5 mol/ L and DES at the concentration ≥ 1×10-6 mol/L slightly promoted the apoptosis of the prostate smooth muscle cells, but not dose-dependently, and OHT at the concentrations from 1×10-8 mol/L to 1×10-5 mol/L promoted the apoptosis of the prostate smooth muscle cells dose-dependently (r =0. 363, P =0. 021) and this effect could not be reversed by administration of E2 at the concentration 1×10-8 - 1×10-6 mol/L (P>0. 05). E2, DES, and OHT of different concentrations all increased the ERα and AR positive staining rates of the prostate smooth muscle cells (all P < 0. 05). Contusions OHT suppresses the proliferation and promotes the apoptosis of prostate smooth muscle cells, and these functions do not depend on the estrogen receptor pathway. Low blood OHT concentration after oral administration of TAM and up-regulation of estrogen receptors by OHT may be the caused of the inefficiency of TAM for treatment of BPH.