In vitro methods for analyzing miRNA roles in cancer cell proliferation, invasion, and metastasis

Abstract

MicroRNAs (miRNAs) are small noncoding, single-stranded RNAs consisting of 20–24 nucleotides (Bartel, Cell 116:281–297, 2004), which regulate target genes expression by interacting with 3′-untranslated regions (3′-UTRs) of target mRNAs, leading to translation repression or mRNA degradation (Filipowicz et al., Nat Rev Genet 9:102–114, 2008; Nilsen, Trends Genet 23:243–249, 2007). Accumulating evidence has elucidated them as oncogenes or tumor suppressors in cancers such as hepatocellular carcinoma, breast cancer, and lung cancer (Liu et al., Gastroenterology 136:683–693, 2009; Yu et al., Cell 131:1109–1123, 2007; Zhou et al., Sci Rep 7:42680, 2017; Iorio and Croce, Carcinogenesis 33:1126–1133, 2012). MiRNAs are involved in various biological processes, including cell proliferation (Liu et al., Mol Cancer Res 11:1314–1325, 2013), differentiation (Liu et al., Mol Cancer Res 11:1314–1325, 2013), apoptosis (Pan et al., Oncol Res 24:429–435, 2016), invasion and metastasis (Liu et al., Nat Commun 8:14270, 2017). Understanding the role of miRNAs in tumor gives new perspective on cancer diagnosis and therapy (Rupaimoole and Slack, Nat Rev Drug Discov 16:203–222, 2017; Berindan-Neagoe et al., CA Cancer J Clin 64:311–336, 2014). This chapter will focus on the in vitro methods for identifying miRNAs roles in cell proliferation, invasion, and metastasis in tumor development, which includes CCK-8 assay, Wound Healing assay, and Transwell assay.