- 學位論文
微型核糖核酸mir-30a抑制乳癌細胞移動之探討
Inhibitory effect of mir-30a on motility of breast cancer cells
摘要
MicroRNA (miRNA)是一段長度約23個鹼基對的微型核醣核酸，其透過抑制基因轉譯來達成調節基因功能的目的。miRNA已被證實在腫瘤發展過程中扮演重要角色，其參與腫瘤細胞的生長、癌化、藥物感受性、侵襲及轉移..等影響範圍非常廣泛。近年文獻指出在癌細胞轉移過程中特異性的miRNA會影響上皮和間質細胞轉變 (epithelial-mesenchymal transition, EMT)機制，造成癌細胞運動能力的改變。但是miRNA影響EMT的機制尚未完全清楚，基於此目的，本篇研究主要是想瞭解是否有特殊的miRNA參與EMT過程而影響乳癌細胞轉移?我們利用生物資訊技術在Targetscan資料庫中推測出hsa-mir-30a是vimentin(VIM)的調控者；當我們將hsa-mir-30a轉殖到MDA-MB-231或Hs578T時，證實其的確會抑制VIM蛋白的表現；在共軛焦顯微鏡觀察也得到相同結果；在生物冷光(luciferase)報導基因實驗中，我們證實hsa-mir-30a會結合到VIM的三端不轉譯區(3'UTR)而降低冷光表現；當利用慢病毒(lentivirus)感染MDA-MB-231及Hs578T，使其本身持續大量表達hsa-mir-30a，細胞的轉移和侵襲能力明顯降低。本篇研究，證實在乳癌細胞株中hsa-mir-30a會直接結合到VIM的3'端不轉譯區序列上，導致VIM功能被抑制，最終讓乳癌細胞的轉移能力降低。
關鍵字
微型核糖核酸並列摘要
MicroRNAs (miRNAs), a family of small moleculer of RNAs transcripts, are important gene regulators that play a crucial role in cell tumorigenesis. Recently, it has been reported that miRNA can affect epithelial-mesenchymal transition (EMT) during tumor cell progression. However, the underlying mechanism that regulation of EMT through specific miRNA regarding to prognostic evaluation in breast cancer remains unclear. To this aim, we examined whether there existed a novel biomarker of miRNA in predicting tumor worsen of breast cancer. In the present study, we identified that vimentin(VIM) is a putative target of hsa-mir-30a. Ectopic expression of hsa-mir-30a in the breast cancer cell lines, MDA-MB-231 or Hs578T, VIM protein level is downregulated by hsa-mir-30a. Moreover, we proved that VIM 3'UTR is directly bound by hsa-mir-30a. Further, study in vitro has been shown that both capabilities of tumor invasiveness and motility were significantly inhibited by often induction of hsa-mir-30a in breast cancer cell. Our findings provide support for the prognostic role of hsa-mir-30a in breast cancer progression and may be used to develop a therapeutic target for treatment of breast cancer.