Читать книгу Genomic and Epigenomic Biomarkers of Toxicology and Disease - Группа авторов - Страница 77

Uncontrolled cell cycle is one of the key steps in tumorigenesis. Almost all tumor cells have cell cycle regulation defects, and MM is no exception. MicroRNAs can regulate the process of cell cycle by targeting key regulators that promote or inhibit cell cycle, such as cyclin-cyclin-dependent protein kinase (CDK) complex or other cell growth regulatory genes. Kubo et al. (2011) and Maki et al. (2012) found that the expression level of miR-34b/c in MM cell lines (H2052 and H28) decreased. After the level of miR-34 in cells was increased by transfection, the expression of the cell cycle-related proteins CDK4, CDK6, and CCND1 was inhibited and the proportion of G1 phase cells was significantly increased. When normal pleural cells (LP-9) were transfected with miR-34 inhibitor, the number of G1 phase cells decreased significantly and the expression levels of miR-34 target genes c-MET and Bcl-2 were significantly upregulated. This indicates that miR-34b/c plays an important role in regulating G1 cell cycle arrest (Tanaka et al. 2013). Some studies have also found that tumor cells are inhibited and in S phase by transfecting miR-31 into MM cell HP-1 or inhibiting the expression of endogenous miR-31 in MM cell H2461 (Ivanov et al. 2010).