Abstract P2-03-07: Rhythmic time oscillations of microRNAs in human breast epithelial normal and cancer cell lines

Abstract

Abstract BACKGROUND: Diverse molecular mechanisms are being reported in human breast cancer (BC), which can affect the biochemical functions throughout malignant cells development. The microRNAs (miRNAs) are an emerging class of modulators of gene expression with relevant roles in several biological processes, as oncogenic, tumor-suppressive, and metastatic-influencing in BC cells. Recently, a few reports have implied the possible pattern of expression (time oscillation) of miRNAs in time that may be related to molecular changes in mammalian cells. These findings suggest a biological connection among normal and cancer cells, and rhythmic regulation of some miRNAs, but such connection has not yet been studied. In this study, we aimed to identify and compare the rhythmic expression of miRNAs in human breast epithelial normal and cancer cell lines. METHODS: We used cell culture to explore three cell lines, one breast epithelial normal (MCF10A) and two cancer (MCF-7 and MDA-MB-231) cell lines under standard growth conditions in vitro. The cells were synchronized by serum shock (50% horse serum for 2 h), and we collected sample cells (triplicate) for intervals of 4 hours during 48 hours. Collected cells at 12h to 40h (8 time-points) were genome-wide analyzed of miRNA expression using high-throughput Agilent Human miRNA microarray of 2006 human miRNAs. Analysis for identification of rhythmic miRNAs was developed by cosine analysis in R software. RESULTS: We observed diverse oscillation patterns (minimum 6 patterns, i.e. cosine or sine oscillation) of miRNAs in cell lines. Each cell line shows approximately 85 miRNAs with rhythmic oscillation. These also showed distinct phases between cell lines, which could suggest as part of molecular changes in breast normal and cancer cell lines. CONCLUSIONS: Our results suggest that miRNAs may present rhythmic oscillation in the regulation of molecular changes of human breast normal and cancer cells. Citation Format: Chacolla RJ, Trevino VM, Scott SP, Moreno JE. Rhythmic time oscillations of microRNAs in human breast epithelial normal and cancer cell lines. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-03-07.