Aptamer是一種短片段單股的DNA、RNA或胜肽分子，利用其形成二級結構的特性，可以專一性的與蛋白質的特定位置做鍵結，而對蛋白質的功能造成影響，並且可以透過專一性aptamer來研究蛋白質的功能、交互作用，具有類似抗體的功能。Galectin-1是一種具有carbohydrate recognition domains(Earl et al.)可與細胞表面之β-galactosides結合，屬於lectin家族之一。galectin-1對於生長調節、腫瘤形成、免疫、以及細胞貼附、移動扮演一個重要的角色。本實驗室先前的研究即指出，galectin-1能增進口腔癌細胞的增生、貼附與移動。動物實驗方面也發現到，galectin-1基因剔除小鼠可延緩口腔癌前病變及口腔癌的形成。因此本研究希望篩選出專一性的galectin-1 DNA aptamers，以改善口腔癌診斷與治療。目前我們已經利用重組galectin-1從隨機的DNA aptamer序列庫中去篩選特定的aptamer，並經由PCR放大後重複篩選。經由反覆的篩選得到了一些有潛力的aptamer，透過多重序列比對的方式去分析這些經過篩選的核酸適體。挑選出有興趣的產物之後，進一步利用了即時定量PCR (real-time PCR)確認aptamer對於galectin-1蛋白親和力。根據結合能力測試，選定了具有高親和力的AP-27、AP-39、AP-74進行PCR及化學合成。針對galectin-1本身及其對於細胞的生理功能，我們測試了血球凝集實驗，初步發現三個候選aptamer並沒有明顯的抑制galectin-1的血球凝集活性。而在aptamer是否影響galectin-1對於口腔癌細胞OC2的貼附實驗，我們驗證了AP-27與AP-39能有效的抑制galectin-1所促進的OC2細胞貼附，而在OC2細胞移行實驗中，我們亦發現aptamer能抑制OC2細胞移行。綜合以上所述，本研究利用重組蛋白SELEX篩選出galectin-1專一性aptamer，並發現能有效抑制OC2細胞的貼附及移行。

Aptamer is a short DNA or RNA fragment that can form complex secondary structure to confer high degree of specificity for its target molecule. According to this property, aptamer can bind to the specific site of proteins and affect the function of proteins. Galectin-1 is one of the lectin families with carbohydrate recognition domains (CRD) which can bind to β-galactosides. In previous studies, galectin-1 play an important role in growth regulation, tumorigenesis, cell adhesion, and migration. Our group had shown that galectin-1 can promote proliferation, adhesion, and migration in oral cancer cell. On the other hand, galectin-1 knockout can delay the development of oral leukoplakia and formation of oral cancer. Thereby, we want to select galectin-1 specific aptamers to improve diagnosis and therapy of oral cancer. We used galectin-1 to select aptamer from random library and amplified the aptamer product by PCR previously. Then, we analysis the aptamer candidates by multiple alignment, and amplify the aptamer candidates by PCR. After getting the aptamer product, we analyze the binding affinity by real-time PCR. According to qPCR binding assay, AP-27, AP-39, and AP-74 may be potential aptamers that targeting galectin-1. We confirm the function of those aptamers by hemoagglutination assay, adhesion and migration assay at oral cancer cell lines. In hemoagglutination assay, we found that AP-39 and AP-74 inhibit hemoagglutination slightly. In cell functional assay, AP-27, and AP-39 dose-dependently block galectin-1 promoted OC2 cells adhesion. On other hand, we also found these three aptamer candidates inhibit galectin-1 promoted OC2 cell migration.

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