Isaksson E, Wang H, Sahlin L, von Schoultz B, Masironi B, von Schoultz E, Cline J M
Department of Oncology, Radiumhemmet, Karolinska Hospital, Stockholm, Sweden.
Breast. 2002 Aug;11(4):295-300. doi: 10.1054/brst.2002.0422.
The novel estrogen receptor ERbeta could be a key factor for proliferation and breast cancer risk. In a primate model for long-term HRT, surgically postmenopausal cynomolgus macaques were treated for 35 months with conjugated equine estrogens (CEE), medroxyprogesterone acetate (MPA), CEE+MPA and tamoxifen (n=5 in all groups). The immunohistochemical expression of ERalpha, ERbeta and IGF-I in breast tissue was quantified by image analysis. Overall the levels of ERbeta were higher than for ERalpha. In untreated animals, the median area of positive cells was 58% and 21%. The lowest levels for ERbeta were seen during treatment with CEE/MPA (3%) and in this group the expression of ERbeta was lower than for ERalpha. Tamoxifen had effects similar to estrogen. ERbeta may have a role to modulate the proliferative response following activation of ERalpha. The results suggest that hormonal treatments have a different influence on the balance ERbeta/ERalpha in breast tissue.
新型雌激素受体ERβ可能是增殖和乳腺癌风险的关键因素。在长期激素替代疗法（HRT）的灵长类动物模型中，对手术绝经后的食蟹猴进行35个月的治疗，治疗药物分别为结合马雌激素（CEE）、醋酸甲羟孕酮（MPA）、CEE + MPA和他莫昔芬（所有组n = 5）。通过图像分析对乳腺组织中ERα、ERβ和IGF-I的免疫组化表达进行定量。总体而言，ERβ水平高于ERα。在未治疗的动物中，阳性细胞的中位面积分别为58%和21%。在用CEE/MPA治疗期间观察到ERβ的最低水平（3%），且在该组中ERβ的表达低于ERα。他莫昔芬具有与雌激素相似的作用。ERβ可能在ERα激活后调节增殖反应中发挥作用。结果表明，激素治疗对乳腺组织中ERβ/ERα平衡有不同影响。
