Differential miRNA expression profiles of primary and relapse lesions of breast cancer patients receiving tamoxifen

Long-term tamoxifen treatment significantly improves the survival of hormone receptor-positive (HR+) breast cancer (BC) patients. However, tamoxifen resistance remains a big challenge for endocrine therapy. We aimed to identify prognostic biomarkers for tamoxifen treatment and explore their role in tamoxifen resistance. We used Exiqon miRCURY™ LNA Array (v.18.0) to detect the miRNA expression profiles in the primary tumors and their matched recurrent/metastatic lesions from six HR+ breast cancer patients who relapsed after TAM treatment. Fold changes ≥ 2 and P values < 0.05 were defined as differential expression. We found that 28 miRNAs were significantly downregulated in recurrent/metastatic lesions compared to primary tumors, and 54 miRNAs were significantly upregulated. In this study, 6 primary tumor samples and 6 matched recurrent/metastatic lesion samples from six HR+ breast cancer patients who relapsed after TAM treatment were analyzed by microRNA array.

长期他莫昔芬（tamoxifen）治疗可显著改善激素受体阳性（hormone receptor-positive, HR+）乳腺癌（breast cancer, BC）患者的生存预后。然而，他莫昔芬耐药仍是内分泌治疗面临的重大挑战。本研究旨在筛选与他莫昔芬治疗相关的预后生物标志物，并探究其在他莫昔芬耐药中的作用机制。

本研究采用Exiqon miRCURY™ LNA芯片（v.18.0），对6名经他莫昔芬（TAM）治疗后复发的HR+乳腺癌患者的原发肿瘤及其配对复发/转移病灶的microRNA (miRNA)表达谱进行检测。以倍数变化≥2且P值<0.05作为差异表达的判定标准。结果显示，相较于原发肿瘤，复发/转移病灶中有28个miRNA显著下调、54个miRNA显著上调。本研究通过microRNA芯片分析了6名经他莫昔芬治疗后复发的HR+乳腺癌患者的6份原发肿瘤样本及6份配对复发/转移病灶样本。