Roan Cherng-Jau, Chuang Jiin-Haur, Hsu Te-Yao, Tsai Hong-Yuan, Pan Lin-Lin, Cheng Jiin-Tsuey
Graduate Institute of Clinical Medical Sciences, Chang Gung University, Kaohsiung Hsien, Taiwan.
J Formos Med Assoc. 2005 Dec;104(12):920-6.
Studies on the expression of estrogen receptors (ERs) in uterine leiomyomata have yielded conflicting results. A controlled study focusing on leiomyomal nodules with same clinical presentations and hormonal milieu was conducted to investigate the role of ER beta (ERbeta) on leiomyomal growth.
Thirty pairs of leiomyomal and myometrial tissues were included in the study. The specimens were obtained from 30 premenopausal women (40-45 years old) with parity 2, and were sampled during the proliferative menstrual phase. All of the leiomyomal nodules were unifocal, medium sized (4-5 cm), intramurally located, and without progressive enlargement for 6 months. The expressions of ERbeta mRNA and protein in leiomyomata and their adjacent myometria were analyzed by reverse transcriptase-polymerase chain reaction and immunohistochemistry using ERbeta-specific antibody, respectively. ER alpha (ERalpha) was simultaneously studied using similar methods. The results were digitally quantified and compared with each other.
All paired tissues (30/30, 100%) showed a higher ERalpha expression level (paired t test, p < 0.05). In most leiomyomal nodules (27/30, 90%), both ERbeta and ERalpha exhibited no differences in mRNA levels compared to their adjacent myometria (p > 0.05), but the ratio of ERbeta/ERalpha (expression index) was lower (p < 0.05) in leiomyomal tissue. Although the immunoreactivity scores for ERbeta were similar in paired tissues, more ERbeta-positive cells were detected in myometrial specimens than in their leiomyoma counterparts (mean of 62% vs 56%). Furthermore, the distribution pattern of ERbeta in leiomyoma (nuclear and cytoplasmic) was different from that in the corresponding myometrium (nuclear). The lower ERbeta/ERalpha expression index in stationary leiomyoma suggests that the relative abundance of ERbeta and ERalpha, rather than their individual amounts, determines the existence and development of leiomyoma.
This study demonstrated that in premenopausal women, ERbeta is not increasingly expressed in the leiomyomal nodules which show no progressive enlargement. The distinctive ERbeta-to-ERalpha ratio rather than their individual amounts, is associated with the stationary status of the leiomyomal nodule.
关于子宫平滑肌瘤中雌激素受体（ERs）表达的研究结果相互矛盾。本研究通过聚焦具有相同临床表现和激素环境的平滑肌瘤结节，探讨雌激素受体β（ERβ）在平滑肌瘤生长中的作用。
本研究纳入30对平滑肌瘤组织和肌层组织标本。标本取自30名绝经前、40 - 45岁、孕次为2次的女性，于增殖期月经阶段采集。所有平滑肌瘤结节均为单发病灶、中等大小（4 - 5cm）、位于肌壁间且6个月内无进行性增大。分别采用逆转录 - 聚合酶链反应和免疫组织化学方法，使用ERβ特异性抗体分析平滑肌瘤及其相邻肌层中ERβ mRNA和蛋白的表达。同时采用类似方法研究雌激素受体α（ERα）。对结果进行数字化定量并相互比较。
所有配对组织（30/30，100%）显示ERα表达水平较高（配对t检验，p < 0.05）。在大多数平滑肌瘤结节（27/30，90%）中，与相邻肌层相比，ERβ和ERα的mRNA水平均无差异（p > 0.05），但平滑肌瘤组织中ERβ/ERα（表达指数）较低（p < 0.05）。尽管配对组织中ERβ的免疫反应评分相似，但在肌层标本中检测到的ERβ阳性细胞多于其对应的平滑肌瘤（平均分别为62%和56%）。此外，ERβ在平滑肌瘤中的分布模式（核内和胞质）与其相应肌层（核内）不同。静止性平滑肌瘤中较低的ERβ/ERα表达指数表明，ERβ和ERα的相对丰度而非其各自的量，决定了平滑肌瘤的存在和发展。
本研究表明，在绝经前女性中，无进行性增大的平滑肌瘤结节中ERβ并非过度表达。ERβ与ERα的独特比例而非其各自的量，与平滑肌瘤结节的静止状态相关。
