肝癌標的胜肽之尋找及其在標的化療之應用

Identification of a Novel Peptide Ligand for Targeted Drug Delivery against Hepatocellular Carcinoma

羅元駿(Albert Lo)

指導教授 ： 吳漢忠 ； 林欽塘

國立臺灣大學/醫學院/病理學研究所/碩士(2007年)

https://doi.org/10.6342/NTU.2007.01117

摘要

肝癌在世界上的發生率排行為第五位，而導致癌症病患死亡排行為第四位。在美國，罹患肝癌的病人即使在接受傳統治療，五年存活率也僅有8.9%，使得肝癌為致死率第二高的癌症。在台灣，肝癌為造成癌症病患死亡的主因之一，每年約奪走6000~8000人的生命。目前有許多新興的治療策略持續的被發展來治療這個疾病。利用噬菌體顯現法(phage display)的方法，我們找到一種肝癌細胞的標的胜肽。在活體外，藉由ELISA與flow cytometry分析，此PC94噬菌體顯現的標的胜肽具有與肝癌細胞專一性結合的能力。在活體內，PC94噬菌體也可以和異體移植的肝癌細胞有專一性的結合，而不與正常組織結合；同時，PC94噬菌體專一性結合到異體移植的肝癌細胞的能力會被相對應的標的胜肽SP94競爭抑制。而免疫染色也證實此表現標的胜肽的PC94噬菌體只聚集在異體移植的肝癌細胞卻不聚集於正常組織。當標的胜肽SP94與微脂體包裹化學治療藥物連結後，可應用於引導抗癌藥物至異體移植的肝癌細胞，有效地殺死肝癌細胞。同時，PC94噬菌體表現之標的胜肽與其合成之標的胜肽SP94具有與肝癌病人檢體專一性結合的能力。因此，該標的胜肽亦可被應用於作為開發肝癌檢驗試劑，同時對於未來在臨床肝癌病患的治療方面也具有極大的潛力。

關鍵字

肝癌 ； 噬菌體顯現法 ； 標的治療

並列摘要

Hepatocellular carcinoma (HCC) is the fifth most common cancer and ranks the forth leading cause of cancer death worldwide. The 5-year survival rate of individuals with liver cancer in the United States is only 8.9% despite aggressive conventional therapy, marking this malignancy as the second most lethal cancer. In Taiwan, liver cancers cause 6000~8000 deaths annually and rank the leading cause of cancer death. Novel treatment strategies derived from increased knowledge of molecular oncology are constantly being developed to cure this disease. In this study, we describe the identification of a novel peptide (SP94) which could bind specifically to HCC cells using in vitro phage display. In vitro, the phage clone PC94 was able to bind to HCC cell lines but not normal cells by ELISA and flow cytometry analysis. In vivo, PC94 has homing ability to tumor tissues but not normal visceral organs in human HCC xenografts model. In addition, the homing ability of PC94 could be competitively inhibited by synthetic peptide SP94. Immunohistochemical staining also confirmed that the localization of PC94 were found in the tumor tissues but not in SP94 competed tumor tissues nor in the normal organs. Furthermore, with conjugation of the targeting peptide SP94 and liposomes containing doxorubicin, the targeting drug delivery system enhanced the therapeutic efficacy against human HCC xenografts through decreased tumor vessels density and enhanced tumor apoptosis. Moreover, PC94 and biotin-labeled SP94 could recognize the unknown target protein expressed on the cell surface in surgical specimens from HCC patients. Our results indicate that this targeting peptide has a strong clinical potential as a drug delivery guider in the treatment of HCC.

並列關鍵字

Hepatocellular carcinoma ； Phage display ； Targeted therapy

參考文獻

Al-Batran, S.E., Bischoff, J., von Minckwitz, G., Atmaca, A., Kleeberg, U., Meuthen, I., Morack, G., Lerbs, W., Hecker, D., Sehouli, J., et al. (2006). The clinical benefit of pegylated liposomal doxorubicin in patients with metastatic breast cancer previously treated with conventional anthracyclines: a multicentre phase II trial. British journal of cancer 94, 1615-1620.

Allen, T.M. (1994). Long-circulating (sterically stabilized) liposomes for targeted drug delivery. Trends in pharmacological sciences 15, 215-220.

Allen, T.M. (2002). Ligand-targeted therapeutics in anticancer therapy. Nature reviews 2, 750-763.

Allen, T.M., and Cullis, P.R. (2004). Drug delivery systems: entering the mainstream. Science 303, 1818-1822.

Arap, W., Pasqualini, R., and Ruoslahti, E. (1998). Cancer treatment by targeted drug delivery to tumor vasculature in a mouse model. Science 279, 377-380.