前言：在台灣口腔癌與嚼食檳榔是有相關的，放射治療是其中重要的一種治療方式。過去的研 究證實微核醣核酸17-5p（microRNAs 17-5p；miR 17-5p，一種RNA的分子）在經由放射線照射 過後的鱗狀癌細胞株OC3（長期嚼食檳榔但不抽菸之口腔鱗狀細胞癌之細胞株）之中會表現出 來，還發現miR 17-5p 會抑制下游蛋白p21的表現並增加放射線的敏感度。本篇研究中，我們利 用了數組人類凋亡蛋白釐清了相關蛋白對於微核醣核酸17-5p 的調控。 材料和方法：細胞溶解產物均來自於具有小干擾RNA或微核醣核酸17-5p 鱗狀癌細胞株OC3， 並分析其凋亡蛋白的表現。微核醣核酸17-5p 相關之凋亡蛋白會再利用西方墨點法Western blotting 來確認。利用放射線照射無 p53 和有高度的 p53 鱗狀癌細胞株OC3，再接受碘化與流式 細胞儀的檢驗。 結果：使用人類凋亡蛋白組（R&D Systems; catalog # ARY009），我們觀察到在放射線照射後的 鱗狀癌細胞株 OC3 中，在微核醣核酸 17-5p 相對反義寡核甘酸或控制組寡核甘酸的調控鱗狀癌 細胞株 OC3 下有 35 種凋亡蛋白具有其相對應的反應。其中一些蛋白質，包括 p21, p53, TNF RI, FADD, cIAP-1, HIF-1α, 與 TRAIL R1，這些模組的增強與減弱表現方式與使用西方墨點法確認後 是相同的。於此我們更進一步釐清 p53 在鱗狀癌細胞株 OC3 經放射線照射過後的角色，我們將 p53 過度表現，證實鱗狀癌細胞株 OC3 中 p53 的表現增加會阻斷癌細胞進入 G2/M 周期的效果 是顯著的。 結論： 在鱗狀癌細胞 OC3 中， 凋亡蛋白 p21 、p53 、TNF RI、FADD、cIAP-1 、HIF-1α 和 TRAIL R1 表現是會受到微核醣核酸 17-5p 調控的。對於鱗狀癌細胞株 OC3 中，調控促進 p53 蛋白表現，對於因嚼食檳榔引起的口腔癌細胞放射線敏感度的調節是有影響的。

Background and purpose : Betel nut chewing is associated with oral cavity cancer in Taiwan. Radiotherapy is one of the therapeutic approaches. Our previous study demonstrated that microRNA (miR)-17-5p (one of the miR-17-92 polycistronic miRNAs) was enhanced in the irradiated OC3 cancer cell line (which was established from oral squamous cell carcinoma in a long-term betel nut chewer who did not smoke), and miR-17-5p was also found to inhibit downstream protein p21 expression and induce radiosensitivity. In this study, we used a human apoptosis protein array to clarify which apoptosis-related proteins are modulated by miR-17-5p. Materials and Methods : Total cell lysates from OC3 cells with control small interfering (si)RNA or miR-17-5p were used to analyze apoptosis-related proteins. A specific miR- 17-5p effector apoptosis-related protein was confirmed by Western blotting. To confirm the role of p53 in irradiated OC-3 cells, OC3 cells without or with a p53-overexpressing clone were irradiated and examined by propidium iodide staining and flow cytometry. Results : Using a human apoptosis protein array analysis (R&D Systems; catalog # ARY009), we simultaneously detected the relative expressions of 35 apoptosis-related proteins in OC3 cells that were treated with an miR-17-5p antisense oligonucleotide (AS-ODN) or a control ODN. Several proteins, including p21, p53, TNF RI, FADD, cIAP-1, HIF-1α, and TRAIL R1, were found to be up- or downregulated by miR-17-5p in OC3 cells; their expression patterns were also confirmed by Western blotting. We further clarified the role of p53 in irradiated OC3 cells, using a p53 overexpression strategy, and results revealed that enhancement of p53 expression significantly enhanced radiation-induced G2/M arrest of OC3 cells. Conclusions : miR-17-5p regulated the apoptosis-related proteins of p21, p53, TNF RI, FADD, cIAP-1, HIF-1α, and TRAIL R1 in OC3 cells; interestingly, its effect on p53 protein expression contributed to modulating the cell cycle arrest of OC3 cells.