Kurozumi Sasagu, Yamaguchi Yuri, Kurosumi Masafumi, Ohira Miki, Matsumoto Hiroshi, Horiguchi Jun
Division of Breast Surgery, Saitama Cancer Center, Saitama, Japan.
Department of Thoracic and Visceral Organ Surgery, Gunma University Graduate School of Medicine, Gunma, Japan.
J Hum Genet. 2017 Jan;62(1):15-24. doi: 10.1038/jhg.2016.89. Epub 2016 Jul 21.
MicroRNAs (miRNAs) are short non-coding RNAs that regulate the function of target genes at the post-transcriptional phase. miRNAs are considered to have roles in the development, progression and metastasis of cancer. Recent studies have indicated that particular miRNA signatures are correlated with tumor aggressiveness, response to drug therapy and patient outcome in breast cancer. On the other hand, in routine clinical practice, the treatment regimens for breast cancer are determined based on the intrinsic subtype of the primary tumor. Previous studies have shown that miRNA expression profiles of each intrinsic subtypes of breast cancer differ. In hormone receptor-positive/human epidermal growth factor receptor 2 (HER2)-negative breast cancer, miRNA expressions are found to be correlated with endocrine therapy resistance, progesterone receptor expression and heat shock protein activity. Some miRNAs are associated with resistance to HER2-targeted therapy and HER3 expression in HER2-positive breast cancer. In triple-negative breast cancer, miRNA expressions are found to be associated with BRCA mutations, immune system, epithelial-mesenchymal transition, cancer stem cell properties and androgen receptor expression. As it has been clarified that the expression levels and functions of miRNA differ among the various subtypes of breast cancer, and it is necessary to take account of the characteristics of each breast cancer subtype during research into the roles of miRNA in breast cancer. In addition, the discovery of the roles played by miRNAs in breast cancer might provide new opportunities for the development of novel strategies for diagnosing and treating breast cancer.
微小RNA（miRNA）是短链非编码RNA，可在转录后阶段调节靶基因的功能。miRNA被认为在癌症的发生、发展和转移中发挥作用。最近的研究表明，特定的miRNA特征与乳腺癌的肿瘤侵袭性、对药物治疗的反应以及患者预后相关。另一方面，在常规临床实践中，乳腺癌的治疗方案是根据原发性肿瘤的内在亚型来确定的。先前的研究表明，乳腺癌各内在亚型的miRNA表达谱不同。在激素受体阳性/人表皮生长因子受体2（HER2）阴性乳腺癌中，发现miRNA表达与内分泌治疗耐药性、孕激素受体表达和热休克蛋白活性相关。在HER2阳性乳腺癌中，一些miRNA与对HER2靶向治疗的耐药性和HER3表达相关。在三阴性乳腺癌中，发现miRNA表达与BRCA突变、免疫系统、上皮-间质转化、癌症干细胞特性和雄激素受体表达相关。由于已经明确miRNA的表达水平和功能在乳腺癌的不同亚型中存在差异，因此在研究miRNA在乳腺癌中的作用时，有必要考虑每种乳腺癌亚型的特征。此外，miRNA在乳腺癌中所起作用的发现可能为开发乳腺癌诊断和治疗的新策略提供新的机会。
