探討miR-449b促進前列腺癌細胞侵襲轉移之機制

前列腺癌(Prostate cancer；CaP)是與男性相關的癌症，也是台灣癌症十大死因之一。過去研究顯示大部分的前列腺癌與男性荷爾蒙有密切的關係，臨床上對於前列腺癌的治療方式有荷爾蒙療法、手術、放射線治療等。然而近年來，有許多研究指出異常之微型核糖核酸(MicroRNA；miRNA)表達與腫瘤的惡化有關，在腫瘤發展進程中miRNA扮演著一個極為重要的角色，miRNA是一段長度約21-23個鹼基對的非編碼RNA分子，透過抑制基因轉譯，達到基因功能的調節。在先前研究發現miR-449b在乳癌中是扮演致癌基因的角色，但在前列腺癌中的功能仍尚未清楚。利用Targetscan和microRNA.org網站上的生物資訊比對分析，預測出膀胱癌缺失基因1 (Deleted in bladder cancer protein 1；簡稱DBC1、DBCCR1)之3′-UTR有miR-449b標的的位置。本研究透過雙重冷光報導基因分析(dual-luciferase reporter assay)，發現miR-449b會結合在DBC1-3′-UTR上，進一步利用西方墨點法(western blot)分析結果也顯示miR-449b抑制DBC1蛋白表現。為了更進一步探討miR-449b是否與人類前列腺癌細胞之生長，轉移和侵襲能力有關，我們首先建立穩定表達miR-449b之前列腺癌細胞(PC3)，以MTT試驗和流式細胞儀發現miR-449b抑制DBC1後會促進PC3和22Rv的細胞生長，另外由細胞移動和侵襲實驗結果證實抑制DBC1會促進PC3和22Rv細胞移動與侵襲能力。然而利用miR-449b抑制劑的方式抑制PC3細胞內miR-449b的表現得到相反的結果。綜合以上實驗結果顯示miR-449b在前列腺癌的生長與侵襲中扮演了一個重要的角色，亦可當作一個新的前列腺癌診斷與治療的方法。

關鍵字

微型核醣核酸

並列摘要

Prostate cancer is male-related cancer of worldwide, als one of the cancer leading cause of death in Taiwan. In previous studies show that prostate cancer was associated with androgen. Clinically, the ways of prostate cancer treatment therapy method such us androgen, surgical and radiation therapy. However, many studies show that aberration of miRNA was correlated with tumor progression and it is also a pivotal role in it. Micro-RNAs (miRNAs) are small (approximately 21-23 bases), non–protein-coding RNAs that recognize target sequences of imperfect complementarity in cognate mRNAs and either destabilize them or inhibit protein translation. MicroRNAs can posttranscriptionally regulate the expression of hundreds of their target genes. In a previos study revealed miR-449b be an oncogene role in breast cancer, but it was unclear in prostate cancer. We used both TargetScan and microRNA.org. The two software analysis that jointly indentified Deleted in bladder cancer protein 1 3′-UTR has consequencial pairing of target region for miR-449b.We have identified miR-449b as a regulator of DBC1, acting through direct binding to the DBC1 3′ untranslated region by dual-luciferase reporter assay and found the DBC1 level was downregulated by western blot. Alterations of growth and apoptosis of prostate cancer cells, PC3 and 22Rv by stably expressing miR-449b by MTT assay and flowcytomestry. Functional analyses showed that increased miR-449b expression promotes invasion and migration in prostate cancer cells, PC3 and 22Rv cells. Cnoversly, decreased miR-449b expression by its inhibitor could decrease invasion in prostate cancer cells, PC3 cells. Overall, these results indicate that miR-449b functions as a tumor suppressor role by targeting DBC1 and a potential therapeutic target in prostate cancer cells.

並列關鍵字

miR-449b

參考文獻

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探討miR-449b促進前列腺癌細胞侵襲轉移之機制

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