Noncoding RNAs in breast cancer

Abstract

The mammalian transcriptome has recently been revealed to encompass a large number of noncoding RNAs (ncRNAs) that play a variety of important regulatory roles in gene expression and other biological processes. MicroRNAs (miRNAs), the best studied of the short noncoding RNAs (sncRNAs), have been extensively characterized with regard to their biogenesis, function and importance in tumorigenesis. Another class of sncRNAs called piwi-interacting RNAs (piRNAs) has also gained attention recently in cancer research owing to their critical role in stem cell regulation. Long noncoding RNAs (lncRNAs) of >200 nucleotides in length have recently emerged as key regulators of developmental processes, including mammary gland development. lncRNA dysregulation has also been implicated in the development of various cancers, including breast cancer. In this review, we describe and discuss the roles of sncRNAs (including miRNAs and piRNAs) and lncRNAs in the initiation and progression of breast tumorigenesis, with a focus on outlining the molecular mechanisms of oncogenic and tumor-suppressor ncRNAs. Moreover, the current and potential future applications of ncRNAs to clinical breast cancer research are also discussed, with an emphasis on ncRNA-based diagnosis, prognosis and future therapeutics.

WITHDRAWN: Identification of a novel lncRNA‑miRNA‑mRNA competing endogenous RNA network associated with prognosis of breast cancer

“…Breast cancer is a global health threat with its increasing incidence in female population [13]. In spite of recent advances in early detection and cancer therapeutics of breast cancer, contributing to decrease in breast cancer mortality rates, it still remains the main cause for public health concern [14]. Thus, it is of great importance to unveil the molecular switch controlling malignant transformation of breast cancer, which may also contribute to excavate novel prognostic indicators.…”

The novel long non‑coding RNA PRNCR1‑2 is involved in breast cancer cell proliferation, migration, invasion and cell cycle progression

“…Non-coding components that account for large volumes of the human genome have long been predicted to have important roles in various physiological and pathological processes (19). Various types of ncRNAs, including microRNAs, siRNAs, Piwi-interacting RNAs, small nucleolar RNAs and lncRNAs critically contribute to cancer initiation and progression, much more than previously expected (8,(10)(11)(12)20). Increasing evidence has suggested that lncRNAs may be involved in tumor pathogenesis, thus promoting trials of their application in breast cancer diagnosis and prognosis.…”

“…Previous studies have revealed that the pathogenesis of breast cancer is accompanied and driven by a series of successive mutations in genetic and epigenetic networks in breast cells, finally resulting in activation of various hallmarks, malignant transformation and metastasis (5,6). In recent years, it has been suggested that noncoding RNAs (ncRNAs) are responsible for genetic and epigenetic dysregulation, which is associated with various developmental and pathological processes, including tumorigenesis (7,8). However, the specific roles of ncRNAs in breast cancer remain to be investigated.…”

“…Long ncRNAs (lncRNAs) refer to ncRNA transcripts containing >200 nucleotides, which are involved in post-transcriptional regulation of gene expression by interfering with microRNA functioning (9). Through modulating gene expression at the transcriptional, post-transcriptional and epigenetic levels, lncRNAs have been reported to be associated with various physiological and pathological processes, including stem cell development, neurogenesis and oncogenesis (8,9). In various types of human cancer, lncRNAs act as promoters and…”

Knockdown of long noncoding RNA TP73‐AS1 suppresses the malignant progression of breast cancer cells in vitro through targeting miRNA‐125a‐3p/metadherin axis

“…LncRNAs are a class of endogenous transcripts with more than 200 nucleotides, whereas microRNAs (miRNAs) are transcripts which consist of approximately 22 nucleotides. In breast cancer, both lncRNAs and miRNAs participate in the initiation and development of malignant breast tumors . Many ncRNAs have been identified and histopathologically linked to breast cancer; however, only a few have been implicated in key cellular function .…”