摘要:甲狀腺未分化癌的腫瘤細胞增殖迅速且易轉移,因為此類細胞失去凋亡調控機制而且迅速的去分化(De-differentaition),因此甲狀腺未分化癌的病人會因為癌細胞迅速增生轉移,平均存活超過六個月,這是內分泌臨床醫師心中的痛。因為過去的臨床報告顯示,合併手術、放射線治療及化學藥物治療顯示這是一種治療成功率極低且致命的癌症。我們於 1999年開始有關甲狀腺未分化癌的研究,早期我們使用腫瘤壞死因子(tumor necrosis factor-α, TNF-α)處理甲狀腺未分化癌的細胞株(ARO cell line),我們在掃描電子顯微鏡下觀察到,TNF-α 可以誘導甲狀腺未分化癌細胞產生型態學上的分化現象,就是細胞膜上的絨毛(Microvilli)會明顯增加,也發現細胞上澄液中的甲狀腺球蛋白濃度成正相關的增加,而血管內皮生長因子(Vascular endothelial growth factor, VEGF)會有意的降低,這是甲狀腺未分化癌細胞再分化 (Re-differentation)的現象。2001年起,我們開始降膽固醇藥物史達汀 (statins, lovastatin)處理甲狀腺未分化癌細胞的實驗,我們發現較低濃度(25μM)的史達汀可以誘導癌細胞產生再分化現象,但在較高濃度下(50 μM),則可以導致癌細胞產生細胞凋亡。其分子機轉都在於史達汀改變了細胞膜上的G-蛋白,特別是 Rho,相關史達汀抑制細胞膜 G-蛋白質,降低甲狀腺未分化癌細胞的侵襲性的研究結果刊登於國外重要期刊 (J Clin Endocrinol & Metab、Endocrinology及Endocrine Related Cancer)。2006年我們進入裸鼠動物實驗模型,我們將 ARO 細胞株植入裸鼠的皮下組織,並且在腫瘤成長後,我們發現使用 5 及 10 毫克/每公斤/每日時,史達汀可以明顯的抑制腫瘤生長,並使腫瘤萎縮,但是使用 1毫克/每公斤/每日時,卻發生腫瘤明顯加速成長的現象,我們稱為『雙元效應』(duality effects) ,本研究成果已被 2010 International Journal of Cancer (IF: 5.444)。此外,我們使用蛋白質體學發現閥蛋白(FLOT1)是史達汀引導甲狀腺未分化癌細胞分化的重要控制因子,而本篇研究刊登於 2012 Journal of Proteomis (IF: 4.878)。爾後,我們發現甲狀腺未分化癌的生長的過程導源於醣類代謝 Pentose Phosphate pathway途徑中的轉酮脢 (transketolase)活化效應,而可以藉由氧化硫胺素 (Oxythiamine, OXT) 造成甲狀腺未分化癌的凋亡,目前論文撰寫中。而基於在甲狀腺細胞的分化中,Dipeptidyl peptidase-IV (DPP-IV, 二肽基肽酶-Ⅳ)只表現在甲狀腺癌細胞,正常的甲狀腺細胞並不會表現 DPP-IV,這將與sodium iodide symptor (NIS)的屌線與唪相關。因此,二肽基肽酶-Ⅳ抑制劑,一個臨床廣泛使用的糖尿病治療藥物,可以抑制未分化癌細胞的二肽基肽酶-Ⅳ表現,引導細胞再分化的機制。 而未來三年中,我們將進一步針對甲狀腺未分化癌細胞再分化 (Re-differentation)的方向,使用 DPP-IV (二肽基肽酶-Ⅳ)的抑制劑 Vildagliptin 來誘導甲狀腺未分化癌細胞分化,希望同步與氧化硫胺素(OXT)、史達汀透過轉酮脢/血管內皮生長因子調控甲狀腺未分化癌細胞(ARO 細胞)凋亡的機制,以蛋白質體學確認不同濃度的 Vildagliptin及史達汀誘導細胞再分化的蛋白質 (第一年);進一步以蛋白質體學分析ARO及 SW579細胞,加上氧化硫胺素 (Oxythiamine, OXT)抑制轉酮脢調控的途徑,觀察合併使用多種藥物,包括 Vildagliptin / Lovastatin /OXT 同時誘導甲狀腺未分化癌細胞凋亡及分化的成果 (第二年);動物實驗部份,我們將 Vildagliptin / Lovastatin /OXT 的口服劑型治療植入 ARO及 SW579細胞株的裸鼠(第三年)。在完成這項基礎應用的研究後,我們將申請進行甲狀腺未分化癌患者的人體臨床試驗,希望可以合併 Vildagliptin / Lovastatin /OXT治療此類病患,製造甲狀腺未分化癌細胞的凋亡,並利用細胞再分化後,增加吸收 I-131同位素的特性,同步進行大劑量 I-131 放射碘。
Abstract: Anaplastic thyroid cancer (ATC) is a fatal malignancy, and it usually progressed rapidly with distant metastasis due to deficiency of apoptotic regulation with de-differentiation, and the average survival would be less than six months. Clinical practitioners knew that this disease canno be cured in combination with operation, radiotherapy and chemotherapy. Since 1999, we initially treated ATC cell line (ARO cells) with TNF-α, the evidences of re-differentiation were firstly observed via scanning electron microscopy, and increasing thyroglobulin levels with decreasing vascular endothelial growth factor (VEGF) were also observed in ARO culture medium after treatment of lovastatin . In 2001, we further used statins (lovastatin), a lipid-lowering drug, to treat ATC cells. Apoptosis could be found in ARO cells treated with higher concentrations, however, re-differentiation was noted in cells treated with lower concentrations (25 μM), while re-differentiation with higher concentration (50 μM). Molecular mechanism revealed that small G-protein (prenylated proteins) in cell membrane, especially for Rho. They paly the pivotal roles for increasing cellular apoptosis and invasiveness and re-differentiation via the treatment of lovastatin. These results were published in Journal of Clinical Endocrinology & Metabolism, Endocrinology and Endocrine Related Cancer, respectively. In 2006, our animal model was carried out, nude mice implanting with ARO cells was established for lovastatin treatment. We found that tumor growth was prominent suppressed in nude mice treated with lovastatin, 5 and 10 mg/kg/day in comparison (higher dose) in comparison] with positive control group. Meanwhile, tumor growth was significantly promoted in mice treated with 1 mg/kg/day as unexpected finding. Lovastatin showed the “duality effects” for tumor apoptosis and progression. Such results were published in 2010 International Journal of Cancer (IF: 5.444). In addition, we use proteomic analysis to prove up-regulation of FLOT1 to be the pivotal role in re-differentiation of ATC cells. This findings were published in 2012 Journal of Proteomis (IF: 4.878). In this study, we found the duality effects could be due to activation transketolase (TKT), an important and non-oxidative part of Pentose Phosphate pathway (PPP), and Oxythiamine (OXT) could inhibit TKT and induce apoptosis of ATC cells. These results will be submitted in the near future. On the other hand, Dipeptidyl peptidase-IV (DPP-IV) will not present in normal thyroid follicular cells, but will be up-regulated in thyroid cancer cell, which was noted closely to be related to sodium iodide symptor (NIS) expression. Therefore, DPP-IV inhibitor, Vildagliptin, one of the widely used anti-diabetic agents, could inhibit DPP-IV expression in ATC cells, thereafter, result in re-differentiation of ATC cells. In the next future three years, we will focus on re-differentiation therapy in ATC cell. We will use Vildagliptin powder, one DPP-IV inhibitor, to inhibit DPP-IV and induce re-differentiation of ATC cells. We hope Vildagliptin could be used together with Lovastatin (inhibition of VEGF) and Oxythiamine (inhibition of TKT). We will use proteomics to confirm proteins changes in various concentrations of treatment of Vildagliptin in ATC cells (year 1); furthermore, we will use ARO cells with SW579 cells, treated with Vildagliptin / Lovastatin /OXT simultaneously for observation synchronization of apoptosis and re-differentiation in ATC/SW579 cells, via proteomics (year 2); We further will implant the ARO cells/SW579 cells in nude mice, then treated with Vildagliptin / Lovastatin /OXT (year 3). After complete preparation for ten years since 2002, we will apply clinical trial for treatment of ATC patients with simultaneous Vildagliptin / Lovastatin /OXT. Our goal in this ten-year series studies will be induce ATC cellular apoptosis together with increasing large dose radioactive iodine (I-131) uptake in ATC after re-differentiation of sodium iodide symptor (NIS) expression.