Department of Ophthalmology, Duke University, Durham, North Carolina 27710, USA.
J Biol Chem. 2010 Feb 19;285(8):5461-71. doi: 10.1074/jbc.M109.037127. Epub 2009 Nov 24.
MicroRNA 183 (miR-183) has been reported to inhibit tumor invasiveness and is believed to be involved in the development and function of ciliated neurosensory organs. We have recently found that expression of miR-183 increased after the induction of cellular senescence by exposure to H(2)O(2). To gain insight into the biological roles of miR-183 we investigated two potential novel targets: integrin beta1 (ITGB1) and kinesin 2alpha (KIF2A). miR-183 significantly decreased the expression of ITGB1 and KIF2A measured by Western blot. Targeting of the 3'-untranslated region (3'-UTR) of ITGB1 and KIF2A by miR-183 was confirmed by luciferase assay. Transfection with miR-183 led to a significant decrease in cell invasion and migration capacities of HeLa cells that could be rescued by expression of ITGB1 lacking the 3'-UTR. Although miR-183 had no effects on cell adhesion in HeLa cells, it significantly decreased adhesion to laminin, gelatin, and collagen type I in normal human diploid fibroblasts and human trabecular meshwork cells. These effects were also rescued by expression of ITGB1 lacking the 3'-UTR. Targeting of KIF2A by miR-183 resulted in some increase in the formation of cells with monopolar spindles in HeLa cells but not in human diploid fibroblast or human trabecular meshwork cells. The regulation of ITGB1 expression by miR-183 provides a new mechanism for the anti-metastatic role of miR-183 and suggests that this miRNA could influence the development and function in neurosensory organs, and contribute to functional alterations associated with cellular senescence in human diploid fibroblasts and human trabecular meshwork cells.
miR-183(微小 RNA 183)已被报道能抑制肿瘤侵袭性,且可能参与纤毛状感觉神经器官的发育和功能。我们最近发现,H₂O₂诱导细胞衰老后,miR-183 的表达增加。为了深入了解 miR-183 的生物学作用,我们研究了两个潜在的新靶点:整合素β1(ITGB1)和驱动蛋白 2α(KIF2A)。Western blot 检测表明,miR-183 显著降低了 ITGB1 和 KIF2A 的表达。miR-183 对 ITGB1 和 KIF2A 的 3′非翻译区(3′UTR)的靶向作用通过荧光素酶测定得到了证实。转染 miR-183 导致 HeLa 细胞的侵袭和迁移能力显著降低,而缺失 3′UTR 的 ITGB1 的表达可使这种降低得到挽救。虽然 miR-183 对 HeLa 细胞的黏附没有影响,但它显著降低了正常二倍体成纤维细胞和人小梁网细胞对层粘连蛋白、明胶和胶原 I 的黏附。缺失 3′UTR 的 ITGB1 的表达也可使这些作用得到挽救。miR-183 对 KIF2A 的靶向作用导致 HeLa 细胞中形成单极纺锤体的细胞略有增加,但在二倍体成纤维细胞或人小梁网细胞中则没有。miR-183 对 ITGB1 表达的调控为 miR-183 的抗转移作用提供了新的机制,并提示该 miRNA 可能影响感觉神经器官的发育和功能,并导致与二倍体成纤维细胞和人小梁网细胞中细胞衰老相关的功能改变。