乳腺癌和癌旁组织雌激素受体β亚型构成比分析

Ratio analysis of ERβ isoforms in paired cancerous and adjacent normal breast tissues

目的 探讨乳腺癌和癌旁组织中雌激素受体（ER）β亚型构成比变化.方法 收集87例乳腺癌患者癌和癌旁组织,采用实时荧光定量聚合酶链反应定量测定成对组织中ERβ亚型（ERβ 1、ERβ2和ERβ5）相对表达水平,最终获得各亚型在癌变中的比例.结果 癌组织中ERβ 1、ERβ2和ERβ5的表达水平均较癌旁组织低（P=0.00）.在癌组织和癌旁组织,ERβ5在3种主要亚型中所占阳性比例均最高（54.02％和75.84％）,尤以癌旁组织为甚,而ERβ 1阳性比例均最低（6.77％和9.74％）.ERβ 1和ERβ2在癌旁组织中阳性比例低于癌组织（Z=-2.24,P=0.025和Z=-4.85,P＜0.01）,而ERβ5在癌旁组织中阳性比例明显高于癌组织（Z=-5.32,P＜0.01）.结论 乳腺癌变过程中ERβ各亚型表达水平均明显下调,但下调幅度差异显著,亚型构成比变化明显,提示ERβ各亚型在癌变过程中表达调控的差异性机制将成为乳腺癌发病机制研究新的突破口.

Objective To illustrate the composition ratio of ERβ isoforms in paired cancerous and adjacent normal tissues from breast cancer patients.Methods Eighty-seven pairs of cancerous and adjacent normal tissues were obtained from breast cancer patients.RT-qPCR was used to determine the relative mRNA expression levels of ERβ isoforms （ER[β1,ERβ2 and ERβ5）,and the composition ratios of ERβ isoforms were analyzed.Results The expression levels of all tested ERβ isoforms （ERβ1,ERβ2 and ERβ5） in breast cancer tissues were much lower than those in adjacent normal breast tissues （P 〈 0.01）.Isoform ratio analysis showed that ERβ5 was the dominant isoform in both cancerous and adjacent normal tissues with a positive detection rate of 54.02 % and 75.84 %,respectively.Meanwhile,ERβ1 had the lowest detection rate （9.74 % and 6.77 % in cancerous and adjacent normal tissues,respectively）.The positive rates for both ERβ1 and ERβ2 were much lower in adjacent normal tissues than those in cancer tissues （Z =-2.24,P =0.025 and Z =-4.85,P 〈 0.01,separately）,while more cancerous tissues were ERβ5-positive in comparison to adjacent normal tissues （Z =-5.32,P 〈 0.01）.Conclusions The expression levels of all the ERβ isoforms are differentially down-regulated with significant alterations in their composition ratios during breast carcinogenesis.Further understanding on molecular mechanisms underlying the differential down-regulation of ER[β isoforms will shed new light on breast carcinogenesis.