卵巢癌在所有的婦科癌症中擁有最高的死亡率，由於其抗藥性與復發率較高的特性使得卵巢癌一直以來都是必須重視的問題。特別是卵巢透明細胞癌（OCCC）的女性患者其預後能力比起其他種類的卵巢癌的亞型來得更差。我們先前的實驗已經研究過FXYD2可以作為OCCC在預後時的標誌物或治療時的標靶。在阻斷FXYD2的功能時可能會誘導自噬形式的細胞死亡。在本篇研究中，我們研究了FXYD2上調時所調控的機制和OCCC中調控FXYD2的機制，並對FXYD2的特異性適體進行了探討。 我們已經知道IL-6可以調控FXYD2的表達，而HNF1B是FXYD2上游的轉錄因子。為了確定FXYD2在OCCC中的轉錄調控機制，我們預測了FXYD2基因得啟動子區域上轉錄因子的結合位點，並使用特定轉錄因子抑制在OCCC中來研究對FXYD2和HNF1B基因表達的影響。我們發現STAT3的抑制劑S31-201和NF-κB的抑制劑Bay11-7082抑制了OCCC細胞中HNF1B和FXYD2的表達，並通過自噬形式的細胞死亡降低了細胞活性，而AP-1抑制劑SR11302並沒有這種結果。然後我們利用OCCC細胞系中的TOV21G建立可誘導的tet-on shFXYD2系統，並確認在OCCC中FXYD2表現量降低可能導致自噬形式的細胞死亡。最後我們根據實驗室先前研究發現的FXYD2特異性適體APF2-38設計了一種較短的適體（APF2-38s）。通過分析其對OCCC細胞結合的親和力和細胞毒性，我們還探討了APF2-38s在OCCC的早期診斷和治療中的應用。我們發現較短的FXYD2特異性適體APF2-38s與OCCC細胞具有高度的親和力，但是它並不影響OCCC細胞的細胞活力。根據本篇研究OCCC中的STAT3和NF-κB能調控FXYD2及其轉錄因子HNF1B，而通過STAT3、NF-κB或shRNA抑制劑抑制FXYD2的表達將導致OCCC產生自噬形式的細胞死亡，這也使得FXYD2成為OCCC治療的潛在標靶。此外，FXYD2特異性適體可用於開發更有效的早期診斷方式在OCCC患者上。

Ovarian cancer has the highest morality rate in gynecological cancers and continues to be a significant problem because of the resistant and relapsed disease. Especially, women with ovarian clear cell carcinoma (OCCC) have poorest prognosis than other subtypes in ovarian cancer. We have previously reported that FXYD2 may serve as a prognostic marker and therapeutic target in OCCC. Blocking FXYD2 function may induce autophagic cell death. Here, we studied the regulating mechanisms for FXYD2 upregulation and the FXYD2-regulated mechanisms for OCCC and characterized the FXYD2-specific aptamers. We have known that IL-6 could regulate the expression of FXYD2 and HNF1B is a transcription factor regulating the FXYD2 expression. To identify the transcriptional regulation of FXYD2, we predicted the binding sites of transcription factors on promoter region of FXYD2 gene and studied the effect of the specific transcription factor inhibitors on the expression of FXYD2 and HNF1B in OCCC. We found that the STAT3 inhibitor S31-201 and the NF-κB inhibitor Bay11-7082, but not the AP-1 inhibitor SR11302, suppressed the expression of HNF1B and FXYD2 in OCCC cells as well as decreased cell viability via autophagic cell death. Then we established the inducible tet-on shFXYD2 system in an OCCC cell line, TOV21G, and confirmed that FXYD2 knockdown in OCCC may cause autophagic cell death. Finally, we designed a shorten aptamer (APF2-38s) derived from the FXYD2-specific aptamer APF2-38, found from our lab’s previous work. We characterized APF2-38s for the applications of OCCC diagnosis and therapy by analyzing its cell binding affinity and cytotoxicity for OCCC. We found the shorten FXYD2-specific aptamer APF2-38s with high affinity to OCCC cells. However, it did not affect the cell viability in OCCC cells. According to this study, FXYD2 and its transcription factor HNF1B are regulated in OCCC via STAT3 and NF-κB. Blocking FXYD2 expression by inhibitors of STAT3 and NF-κB or shRNA would cause autophagic cell death in OCCC, making FXYD2 as a potential target for OCCC therapy. Moreover, FXYD2-specific aptamer may be applied to develop a useful early diagnosis for OCCC patients.

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