長鏈非編碼核醣核酸-SLCO4A1-AS1在肺癌進展的角色

Abstract

轉移過程涉及癌細胞遷移和侵襲的多種步驟過程，是癌症惡性腫瘤的重要特徵。在細胞內，無法轉譯成蛋白質且長度大於兩百鹼基的長鏈非編碼RNA (Long non-coding RNAs; lncRNA) 已經被證實在癌細胞轉移調節中發揮著關鍵作用。本研究發現lncRNA Solute carrier organic anion transporter family member 4A1- antisense 1 (SLCO4A1-AS1) 具有腫瘤抑制因子的功能，在肺癌細胞中表現出抗轉移性與抑制癌幹細胞族群的擴增。此外SLCO4A1-AS1也能夠抑制磷酸化FAK與paxillin的表現量以及細胞骨架 (cytoskeleton filaments)，進而減少癌細胞遷移和侵襲，並與肺腺癌患者更長的總生存期相關。經次世代定序及功能分析發現SLCO4A1-AS1會影響與細胞運動能力相關的基因。並且透過RNA pull-down、蛋白質質譜分析以及RNA immunoprecipitation發現SLCO4A1-AS1直接與DNA結合蛋白 TOX High Mobility Group Box Family Member 4 (TOX4) 相互作用，並且限制由TOX4誘導的遷移和侵襲能力。另外建立SLCO4A1-AS1 與TOX4過表達的細胞株並且執行次世代定序分析發現，neurotensin receptor 1 (NTSR1) 為SLCO4A1-AS1 和 TOX4 的一個新的重要下游標的。從機制上來看，SLCO4A1-AS1作為TOX4的誘餌 (decoy) 並且通過阻斷TOX4與NTSR1啟動子的相互作用進而阻止NTSR1轉錄。從功能上來說，NTSR1通過細胞骨架重塑促進癌細胞遷移和侵襲，NTSR1的沉默顯著的抑制由TOX4誘導的遷移和侵襲能力。綜上所述，這證據顯示了SLCO4A1-AS1拮抗TOX4/NTSR1信號傳導，並在抑制肺癌細胞遷移和侵襲中發揮關鍵作用。 本研究的目標在於肺腺癌中開發未知的lncRNA並探討其在腫瘤調控中的生理功能。同時，我們還希望釐清癌症、基因及生物訊息之間複雜的關係，並且期望研究成果除了能成為癌症早期診斷的生物標誌，並對癌症治療提供分子標的。希望最終能應用於臨床上抗癌藥物的開發及拓展新的治療策略。

Metastasis is a multistep process involving the migration and invasion of cancer cells, which is a hallmark of cancer malignancy. Recently, it has been discovered that long non-coding RNAs (lncRNAs), which are RNA molecules longer than two hundred base pairs and cannot be translated into proteins, play crucial roles in regulating the metastasis of cancer cells. This study discovered that the lncRNA solute carrier organic anion transporter family member 4A1-antisense 1 (SLCO4A1-AS1) acts as a tumor suppressor. It exhibits anti-metastatic properties and inhibits the expansion of cancer stem cell population in lung cancer cells. Additionally, SLCO4A1-AS1 has the ability to reduce cancer cell migration and invasion by inhibiting the phospho-FAK and phosphor-paxillin, as well as disrupting cytoskeleton filaments. This lncRNA is also associated with longer overall survival in lung adenocarcinoma patients. Through next-generation sequencing and functional analysis, it was found that SLCO4A1-AS1 affects genes related to cell movement. Furthermore, using techniques such as RNA pull-down, protein mass spectrometry analysis, and RNA immunoprecipitation, it was discovered that SLCO4A1-AS1 directly interacts with the DNA-binding protein TOX High Mobility Group Box Family Member 4 (TOX4) thereby restricting TOX4-induced migration and invasion. Furthermore, the establishment of cell lines overexpressing SLCO4A1-AS1 and TOX4, followed by next-generation sequencing analysis, revealed that neurotensin receptor 1 (NTSR1) is a novel and convergent downstream target of SLCO4A1-AS1 and TOX4. Mechanistically, SLCO4A1-AS1 acts as a decoy for TOX4 and blocks the interaction between TOX4 and the NTSR1 promoter, thereby inhibiting NTSR1 transcription. Functionally, NTSR1 promotes cancer cell migration and invasion by remodeling the cytoskeleton, and silencing NTSR1 significantly inhibits the migration and invasion induced by TOX4. In summary, this evidence shows that SLCO4A1-AS1 antagonizes the TOX4/NTSR1 signaling pathway and plays a key role in inhibiting lung cancer cell migration and invasion. The purpose of this study is to develop unknown lncRNAs in lung adenocarcinoma and explore their physiological functions in tumor regulation. Additionally, we aim to understand the intricate connections between cancer, genes, and biological information, with the goal of identifying potential biomarkers for early cancer detection and molecular targets for cancer therapy. Ultimately, these findings could contribute to the development of anticancer drugs and the exploration of novel treatment approaches in clinical settings.