miRNA在許多癌症基因調控，都參與並且扮演著重要的角色，先前有研究指出，在mitogen-activated protein kinases pathway (MAPK pathway)過度活化的惡性黑色素腫瘤當中， miR-524-5p與miR-596這兩個miRNA的表現量異常的降低，且當重新增強這兩個miRNA的表現量之後，會抑制黑色素腫瘤的增值、爬行和侵襲等諸多細胞功能。是非常具有效力的腫瘤抑制miRNA。但是至目前為止，此二種miRNA在黑色素腫瘤細胞當中所受到的下調機制依舊是未知，找出在黑色素腫瘤當中此二種miRNA之調控機制便是此研究所要探討之主軸 p53是一個週知的腫瘤抑制蛋白，通過轉錄的調控，活化或抑制多種與癌症相關的基因轉錄，也有諸多研究顯示p53也會調控許多癌症相關miRNA的轉錄。在此研究當中，我們假設p53可能為調控miR-524-5p與miR-596這兩個miRNA的轉錄因子。在研究中我們發現，當p53的表現量在黑色素腫瘤細胞中上升時，miR-524-5p與miR-596的表現量便有隨之上升之趨勢，而p53表現受到抑制時，miR-524-5p與miR-596的表現量也有下調的趨勢，p53與這兩個miRNA之表現，是有著正相關的關聯性，且在miR-524-5p當中最為明顯，所以，為了驗證p53是否會直接調控其轉錄，我們也預測了miR-524-5p的啟動子序列，進一步發現此序列上可能有潛在p53連接位點。最後通過建立miR-524-5p的啟動子序列之冷光報導基因，試圖證明與了解p53是否直接的與miR-524-5p的啟動子序列進行連接並調控其轉錄。 ;miRNAs are involved in an important role in the regulation of many cancer-related genes. It has been found that the expression levels of miRNA miR-524-5p and miR-596 were significantly low in melanoma with high activated mitogen-activated protein kinases pathway （MAPK pathway）. When the expression levels of the two miRNAs are overexpressed, cell functions such as proliferation, migration, and invasion of melanoma tumors are repressed. However, the down-regulation mechanism of these two miRNAs in melanoma is still unclear. Therefore, the aim of this study is to identify how these two miRNAs are regulated in melanoma. p53 is a well-known tumor suppressor protein that activates or inhibits the transcription of many cancer-associated genes through transcriptional regulation. Many studies have also shown that p53 as well regulates the transcription of many cancer-associated miRNAs. In this study, we hypothesized that p53 may be a transcription factor that regulates two miRNAs, miR-524-5p and miR-596. The increase of MAPK pathway in melanoma may cause the inhibition of p53 activity, which may result in decrease of miR-524-5p and miR-596 in melanoma. Our results indicated that the expression levels of p53 can affect the expressions of miR-524-5p and miR-596. The expressions of p53 and the two miRNAs were positively correlated. In order to verify whether p53 is directly regulator for miR-524-5p transcription, we predicted the promoter sequence of miR-524-5p according data base or web and further cloned the potential p53 binding sites on luciferase reporter plasmid. Finally, we try to test whether or not p53 is directly binding to the promoter sequence of miR-524-5p and regulates its transcription.
