Abstract
摘要：微核醣核酸是一個非譯碼的小單股核醣核酸，藉由與信息核醣核酸的 3’端未轉譯區發生鍵結，來調控細胞的生理與病理過程，包括細胞週期、凋亡和腫瘤生成。 我們前導的微陣列研究，發現 7個微核醣核酸標幟是兒童白血病的復發危險因；另外也使用流式細胞儀，來分析微量殘留癌細胞量來當作細胞級的疾病復發危險因子。在同時交互比對驗證時，發現在這 7個微核醣核酸中，miR-30d更具有顯著的預測效果。因此我們在前期國科會 3年計畫中，使用基因工程成功選殖特有的 miR-30d基因剔除鼠。 已有三種化學物引起小鼠腫瘤的動物模式被建立以研究人類腫瘤機制，最近的研究發現它們都屬與發炎有關的癌症生成模式，有著非常相似的分子訊息傳遞路，雖然同樣的基因在不同的細胞或不同的癌症模式，有著不同的功能。 miR-30d 基因剔除鼠的表現型分析和 DEN 引起的肝癌模式完全吻合。因此我們假設miR-30d應該會調控與這個訊息傳遞途徑相關的基因；我們也假設 miR-30d 在另外兩個與發炎有關的癌症生成模式(大腸癌、皮膚癌)中，也會調控與這個信號途徑相關的基因。越多的研究顯示 IL-6/STAT3 連結著發炎和癌症生成、miR-30d 在三種人類常見的癌症(肝癌，黑色瘤，卵巢瘤)被發現是致癌的微核醣核酸以及 IL-6與 miR-30d有可相鍵結的位置等資料更加強我們的假設。 另外，miR-30d基因剔除鼠在接受放射線照射後，有些組織會有比野生型鼠更嚴重的細胞凋亡，因此我們假設小鼠特有的 miR-30d，應該會調控小鼠的細胞凋亡途徑相關的基因。已有研究顯示有些物種 (人、斑馬魚、大鼠) 的 miR-30d 會直接作用在 p53，來調控細胞凋亡，更堅定我們的假設。 基於上述的進展，我們將持續的研究計畫為： 第一部分： (1) 確認在這三種化學物引起腫瘤生成的模式中， miR-30d所扮演致癌微核醣核酸的角色。 (2) 鑑定並驗證 miR-30d 在上述這三種與發炎有關的癌症生成模式中各自的目標基因，因在不同的細胞或不同的癌症模式中，會有著不同的目標基因。 第二部分： (1) 闡明、鑑定並驗證小鼠特有的 miR-30d在小鼠正常細胞的凋亡信號途徑所作用的目標基因以及扮演的角色。 (2) 闡明、鑑定並驗證小鼠特有的 miR-30d，在上述三種化學物所引起的腫瘤細胞的凋亡信號途徑所調控的目標基因以及扮演的角色。 第三部分： (1) 證實 miR-30d在慢性 B型肝炎引起的肝癌生成中，是致癌的微核醣核酸。 (2) 證實miR-30d在慢性 B型肝炎引起的肝癌和上述三種與發炎有關的癌症生成模式中可作為分子治療標的。
Abstract: MicroRNAs are small non-coding single-stranded RNA molecules that regulate a variety of physiological and pathological processes including cell cycle, apoptosis and tumorigenesis by partially complementary binding to the site in the 3' UTR of its target messenger RNA. Yu et al. (2008) had already reported one novel 5-miR signature could predict survival and relapse in non-small-cell-lung cancer. Our pilot Microarray study has identified another 7-miR signature as the novel molecular relapse risk factor for childhood ALL, the most common malignancy among the childhood cancers. We have also analyzed minimal residual disease (MRD) by using flow cytometry as the cellular relapse risk factor for newly diagnosed ALL. Among this 7-miR signature, we identified one with more significant prediction hazard ratio, miR-30d, by validation with its expression patterns in positive MRD patients as the target to generate genetically engineered mouse model for further function analysis. Under the NSC (98-2628-B-002-007-MY3) grant, we have bred the unique miR-30d-/- mice with important progress. Three chemical-induced tumors in mice have been well established as the animal models of human tumors for study. Recent reports reveal these 3 murine cancer models share the similar molecular pathogenesis signal pathways and all are described as inflammation-associated carcinogenesis, although the impact of same gene(s) on different cancer development is cell type or model specific. Based on our preliminary evidence that the phenotype of miR-30d-/- mice completely match the recent discovered molecular pathogenesis pathway in DEN-induced HCC, we hypothesize the miR-30d should target and regulate the gene(s) involved in this pathway. We further hypothesize the miR-30d may also target and regulate the gene(s) involved in other two carcinogens-induced tumorigenesis with similar signaling to that of DEN-induced HCC. The growing information of IL-6/STAT3 as a link and miR-30d as an oncomiR in three popular human tumors, HCC, melanoma and ovary CA as well as there is putative binding site in IL-6 for miR-30d further strengthen our hypothesis. Based on our preliminary demonstration with enhanced γ-irradiation-induced apoptosis in some tissues of miR-30d-/- mice, we hypothesize the mmu-miR-30d should target and regulate the gene(s) involved in the mmu-miR-30d-mediated apoptotic pathway. The increasing reports reveal the miR-30d of species other than mouse (human, zebrafish and rat) directly targets the p53 to regulate the apoptosis process further reinforce our hypothesis. As the above progress, we continue elucidating the novel role of miR-30d as the following: Part I: (1) To further confirm the role of miR-30d as oncomiR in these 3 chemical-induced carcinogenesis models. (2) To identify and validate the target gene(s) of miR-30d in these 3 tumor models through the similar inflammation-associated carcinogenesis but may target different gene(s) in different cells or cancer models. Part II: (1) To elucidate the novel role as well as identify and validate the target gene(s) of mmu-miR-30d in normal (non-tumor) mouse cell-specific apoptotic pathway. (2) To elucidate the novel role as well as identify and validate the target gene(s) of mmu-miR-30d in 3 murine induced -tumor apoptotic pathways. Part III: (1) To prove the miR-30d as an oncomiR in the pathogenesis of chronic HBV-induced HCC. (2) To elucidate the role of miR-30d as a molecular therapeutic target in chronic HBV-induced HCC and 3 chemical-induced cancers.
Keyword(s)
微核醣核酸
目標基因
第一部分：發炎相關的致癌機轉
人類腫瘤的動物模
式
致癌微核醣核酸
第二部分：微核醣核酸調控的凋亡路徑
第三部分：分子標靶治
療
microRNA
target gene(s)
Part I: inflammation-associated carcinogenesis
animal models of human tumors
oncomiR
Part II: microRNA-mediated apoptotic pathway
Part III: molecular target therapy
