Abstract
摘要:肺癌在台灣與世界各國都高居癌症死亡率的榜首。數十年來,對於肺癌的形成過程有了很大的進展,但是肺癌病患的5年存活率依舊很差,病人仍然會因肺癌轉移到其他器官而死亡。在亞洲肺腺癌病患的檢體中發現到表皮生長素受體(EGFR)會大量表現以及過度活化,藉此促進腫瘤的生長。這使得表皮生長素受體抑制劑(EGFR TKIs)成為這類病患的首選藥物。但不可避免的,表皮生長素受體會發生抗藥性突變造成這類標靶藥物失去效果。我們先前的研究顯示癌細胞侵襲能力的增加會促使肺癌轉移與標靶藥物的抗藥性,這也是病患存活率偏低的主因。 細胞中,無法轉譯成蛋白質且長度大於200bp的長鏈非編碼核醣核酸(long non-coding RNAs, lncRNAs)已經被證實和腫瘤形成有關。我們發現長鏈非編碼核醣核酸Solute carrier organic anion transporter family member 4A1- antisense 1 (SLCO4A1-AS1)在高轉移能力細胞中的表現量會被抑制。實驗顯示SLCO4A1-AS1會抑制細胞的移動、侵襲與癌幹細胞族群的擴增。此外,SLCO4A1-AS1也能夠抑制FAK與 paxillin的磷酸化以及破壞細胞骨架(cytoskeleton filaments),這顯示出SLCO4A1-AS1會抑制板狀偽足(lamellipodia)與絲狀偽足(filopodia)進而造成細胞移動能力減緩。 在此計畫中,除了探討SLCO4A1-AS1是否會抑制細胞的移動、侵襲與癌幹細胞的擴增外,由於這些作用也會影響表皮生長素受體抑制劑的敏感性,所以我們也想進一步探討SLCO4A1-AS1是否會影響細胞對於表皮生長素受體抑制劑的敏感性,並且利用病患檢體檢測SLCO4A1-AS1能否當成肺癌進展與藥效反應的指標。最終期望能對表皮生長素受體抑制劑抗藥性之病患的治療找出一條新的方向。 在此研究,將完成下列的目標:(1) 確認SLCO4A1-AS1會抑制細胞的移動、侵襲、癌幹細胞族群的擴增以及增加表皮生長素受體抑制劑的敏感性。(2) 找到SLCO4A1-AS1的作用標的與調控機轉。(3) 利用臨床病患的檢體確認SLCO4A1-AS1和SLCO4A1-AS1下游標的與癌細胞轉移、癌幹細胞特徵與表皮生長素受體抑制劑抗藥性的關聯性。
Abstract: Lung cancer remains the leading cause of cancer-related death around world. Over the past decade, a huge advance in human knowledge of lung cancer progression, but the 5-year survival rate is still poor. Patients still die of cancer metastases even in the era of personalized therapy. Epidermal growth factor receptor (EGFR) is a representative oncogene in lung adenocarcinomas (LUAD). Molecular-targeted therapy (EGFR tyrosine kinase inhibitor, TKI) is the first choice for activating EGFR mutations, but acquired resistance develops and limits its application. Our previous work demonstrated that cancer invasion promoted metastases and EGFR TKI resistance. Cancer metastasis and resistance to treatment are two major causes for the poor survival of lung cancer patients. Long non-coding RNA (lncRNA) is a class of non-coding transcripts with lengths greater than 200 nucleotides and players in the development of cancers. We identified that a non-coding transcript- Solute carrier organic anion transporter family member 4A1- antisense 1 (SLCO4A1-AS1) was down-regulated in highly metastatic cancer cells. We demonstrated that SLCO4A1-AS1 reduced cell migration and invasion in PC9/gef, CL1-5, and H1299 cell lines. Importantly, SLCO4A1-AS1 inhibited phosphorylation status of FAK, paxillin and disrupted cytoskeleton filaments, which reduced cell motility. SLCO4A1-AS1 also reduced sphere-forming ability and inhibited aldehyde dehydrogenase (ALDH) activity, suggesting SLCO4A1-AS1 was involved in the maintenance of cancer stem cells. Because cell motility and cancer cell stemness are crucial steps in tumor progression and drug resistance, we suggest that SLCO4A1-AS1 may play an important role in regulating tumor progression and EGFR TKI resistance. In this project, we will investigate the role of SLCO4A1-AS1 in regulation of metastasis, stemness, and EGFR TKI resistance in lung cancer and evaluate whether SLCO4A1-AS1 is a useful signature in predicting patient's prognosis. Through the study of the role of SLCO4A1-AS1, we hope to understand the process of tumor progression and resistant mechanism to EGFR TKIs in NSCLC patients.In this project, we'd accomplish the following aims:Aim 1:Confirm the role of SLCO4A1-AS1 in motility, stemness, and EGFR TKI resistance.Aim 2:Identify the potential targets of SLCO4A1-AS1 and investigate whether the downstream targets of SLCO4A1-AS1 are involved in tumor progression and EGFR TKI resistance.Aim 3:Confirm the association of SLCO4A1-AS1 and potential targets of SLCO4A1-AS1 and the role of SLCO4A1-AS1 on lung cancer stemness, metastasis and EGFR TKI resistance in patients’ samples.
Keyword(s)
長鏈非編碼核醣核酸
肺癌
細胞骨架
抗藥性
Long non-coding RNA
lung cancer
cytoskeleton
resistance