抗MCF-7人類乳腺癌幹細胞之藥物篩選

Specific Targeting of MCF-7 Breast Cancer Stem Cells

陳喬依(Chiau-Yi Chen)

指導教授 ： 曾昭能

共同指導教授 ： 王惠君(Hui - Chun Wang)

高雄醫學大學/藥學院/天然藥物研究所碩士班/碩士(2012年)

摘要

幹細胞對於正常人體生理功能扮演重要角色，正因幹細胞在正常組織扮演重要的角色，所以科學家推論癌症細胞也有類似正常幹細胞之癌症幹細胞，其具有自我更新，持續分裂及分化的能力，來促使癌症增生。癌症幹細胞被認為可以控制癌症的開始形成與維持生長，因此目前都轉變研究方針，改以消滅癌症幹細胞為主要對策。而本研究的主要實驗藥物5-azacytidine，其被篩選出來具有抑制癌症幹細胞的生長，為DNA methyltransferase inhibitor (DNMTI)癌症幹細胞可在無血清培養條件下生長，我們建立幹細胞與癌症幹細胞分離培養技術，可展現癌症幹細胞的特性，而往後的實驗皆以此培養方式，確立癌症幹細胞的平台。首先，以MTT assay 測定5-azacytidine對人類乳腺癌細胞MCF-7的毒殺作用以及存活率，得知此藥物的IC50約為10 μΜ，接著觀察5-azacytidine是否抑制癌症細胞形成mammosphere的能力。此外我們研究藥物對癌症細胞在體外傷口癒合實驗和明膠蛋白酵素遷移的抑制作用，接著觀察藥物抑制細胞生長成細胞群的能力，最後以西方點墨法觀察相關蛋白質的表現。癌症幹細胞具相當高度的化療與放療抗性，所以須先逮住真正的禍首，才有機會治癒癌症，綜合實驗結果可得知，5-azacytidine對於癌症幹細胞有專一性的毒殺作用且能抑制細胞轉移，因此5-azacytidine為治癒癌症指引了新的方向

關鍵字

癌症幹細胞 ； 乳癌 ； 凋亡 ； DNA甲基轉移酶抑制劑

並列摘要

Stem cell plays important roles in the physiological functions of normal human. It is believed that cancer stem cell also contribute heavily to tumor formation. Cancer stem cells can also be found in established cancer cell lines, albeit in low frequency. It’s capable of self-renewal, continuous division and differentiation, thereby promote cancer proliferation. Therefore current research tends to focus on finding therapeutic agents that can eliminate cancer stem cells. In this study we tested the effect of 5-azacytidine, a DNA methyltransferase inhibitor (DNMTI). Cancer stem cells were grown in serum-free culture conditions as tumorspheres. Cytotoxicity of 5-azacytidine in MCF-7 human breast cancer stem cells survival rate was determined by MTT assay. IC50 of this drug to be approximately 10 μΜ. Cancer stem cells display a very high degree of resistance to chemotherapy and radiotherapy. This study suggests that 5-azacytidine has therapeutic potential treating in human breast cancer cell in MCF-7 by selectively targeting cancer stem cells and may provide a more effective therapeutic strategy.
5-azacytidine at this concentration significantly inhibited MCF-7 mammosphere formation, wound healing ability and MMP-9 production. Western blotting indicated 5-azacytidine induced cleavage of caspase-7 and PARP indicative of apoptosis.

並列關鍵字

Cancer stem cell ； Breast cancer ； Apoptosis ； DNA methyltransferase inhibitor

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