High-throughput RNA sequencing on circular RNA profiles of human triple-negative breast cancer and adjacent normal tissues

In an attempt to search for metastasis-associated circRNAs, we performed RNA-sequencing on ribosomal RNA-depleted total RNA from three pairs of triple-negative breast cancer (TNBC) and adjacent normal tissues. A computational pipeline based on the anchor alignment of unmapped reads was used to identify circular RNAs. Taken together, 69,815 distinct circRNAs were found in this study and 87% were derived from exons, and the others were derived from introns, intergenic region and 3′ or 5′ UTR, etc. We further identified 5,033 differentially expressed circRNAs (fold change ≥ 2 and p < 0.05). Among them, 3,726 circRNAs were significantly down-regulated and 1,307 circRNAs were significantly up-regulated in TNBC tissues compared with adjacent normal tissues. These data indicate that circRNAs are abundant in human breast tissues and dysregulation of circRNAs may contribute to breast cancer progression. Circular RNAs profiles of three pairs of triple-negative breast cancer (TNBC) and adjacent normal tissues were generated by RNA deep-sequencing, using HiSeq3000, Illumina.

为探寻与转移相关的环状RNA（circular RNA, circRNA），本研究对三对三阴性乳腺癌（triple-negative breast cancer, TNBC）组织及其配对癌旁正常组织的去除核糖体RNA的总RNA开展了RNA测序。本研究采用基于未比对读段锚定比对的计算分析管线鉴定环状RNA。综上，本研究共鉴定得到69815种不同的环状RNA，其中87%源自外显子，其余分别来自内含子、基因间区以及3'或5'非翻译区等区域。本研究进一步鉴定得到5033个差异表达环状RNA（倍数变化≥2且p<0.05）。相较于配对癌旁正常组织，三阴性乳腺癌组织中有3726个环状RNA显著下调，1307个环状RNA显著上调。上述数据表明，环状RNA在人类乳腺组织中分布广泛，其表达失调可能参与乳腺癌的发生与进展。本研究采用Illumina HiSeq3000平台开展RNA深度测序，构建了三对三阴性乳腺癌组织及其配对癌旁正常组织的环状RNA表达谱。