![](https://static.penana.com/images/chapter/500206/Jg_ct1.png)
這系列的第一集,我們講解了PD1/PDL1的運作原理。488Please respect copyright.PENANAfZNOi75SXt
Link: https://www.penana.com/article/471125488Please respect copyright.PENANA5gA566mQku
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第二集我們講述CTLA4與T cell功用的關係。488Please respect copyright.PENANAvIf3uLMBKw
Link:https://www.penana.com/article/472480488Please respect copyright.PENANANKEtmNnSHv
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第三集我們講述增加T cell順利到達癌細胞位置的其中一種手段。488Please respect copyright.PENANA2au9NpgXrs
https://www.penana.com/article/479229488Please respect copyright.PENANAufkyNlMtjr
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而這一集我們將講解一道關於檢測阻擋PD1的抗體Pembrolizumab成效的研究。488Please respect copyright.PENANAX4QpoHSoyL488Please respect copyright.PENANAFCF6wEWv1Y
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關於阻檔PD1的原理及初心,可參閱第一集,其後可直接跳過第二第三集來到第四集本集。488Please respect copyright.PENANAJmblXAnmXD
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(圖2)現今約只有20%的病人能夠從免疫治療中獲取長遠且持續的正面效果。488Please respect copyright.PENANAQ43mq5G176488Please respect copyright.PENANAtXs4sEeoBE
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其有效的程度實屬可圈可點,如果有方法能夠盡快得知免疫治療沒有預期成效的話,那就可以即時轉用其他治療手段,把握時候嘗試用第二種方法入手打擊癌症。488Please respect copyright.PENANAw5zknX5ToS
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對此,有科學家嘗試量度血液中癌細胞的DNA含量,觀察能否藉此方法預判免疫治療的效果(Ref1)。488Please respect copyright.PENANAgFLjlj0Cnu
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(圖3)癌細胞DNA之所以會出現在血液中,主要由兩大途徑所成。488Please respect copyright.PENANAfX6HfKInwB488Please respect copyright.PENANA95vSxjje2o
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1.癌細胞會利用血液循環系統或者淋巴系統轉移到第二個位置,488Please respect copyright.PENANA4pYEhNcx61
因此血液會有癌細胞的DNA。488Please respect copyright.PENANAXjXpxRQmMP
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2.癌細胞亦會往外釋出名Exosome的物質,裡頭亦含有癌細胞的DNA。488Please respect copyright.PENANAkqta06j1zK
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在這裡,我們暫稱癌細胞在血液中的DNA為ctDNA,Circulating Tumor DNA。488Please respect copyright.PENANA363pSXAgaX
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(圖4)圖中為利用阻擋PD1的抗體Pembrolizumab作治療的兩名病人結果。488Please respect copyright.PENANARb2BseiQXb488Please respect copyright.PENANA4oNlxRmrpx
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紅線為電腦斷層掃描觀察癌細胞大小的影像,而黑線為量度癌細胞在血液(ctDNA)的含量,可見黑線(量度ctDNA的含量)能夠更快預判免疫治療結果成效。488Please respect copyright.PENANAAZoDX8WPMW
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而且,有另外10名接受免疫治療的病人在初期(服用藥物後6-7星期)錄得ctDNA完全下降,亦同樣能夠比電腦斷層掃描觀察更早一步預判成效。488Please respect copyright.PENANAxIQ0KjTvuv
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而研究中有45名免疫治療的病人在初期沒有錄得任何的ctDNA跌幅,癌細胞的體積在其後亦沒有明顯縮細。488Please respect copyright.PENANAZIvgsUhYxl
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對比含放射性的電腦斷層掃描,量度血液的ctDNA只需抽取病人的血液便可,明顯簡單且快捷。488Please respect copyright.PENANAI4m8X8GZTR
只不過每名病人的ctDNA排組均不一樣,先前需要拿取部份癌細胞組織,才能夠有效設計檢測ctDNA的方針。488Please respect copyright.PENANAJ7AjqyTGVs
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無論如何,若然日後能有研究進一步確立此方法的成效及可信性,定必大可增加對抗癌症的效益。488Please respect copyright.PENANAMTqD7CgtVU
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另一方面,透過檢測血液的DNA來預先得知癌細胞的存在,亦是日後檢驗及預防癌症的主流大方向。488Please respect copyright.PENANA0mOlw8mQmo
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如果想我快啲出文的話,請入去Penana網站科普專欄–薯不揀單俾一個like以及Bookmark,這對我非常之重要。488Please respect copyright.PENANADt3ShTeoev
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Link: https://www.penana.com/story/66244/%E7%A7%91%E6%99%AE%E5%B0%88%E6%AC%84-%E8%96%AF%E4%B8%8D%E6%8F%80%E5%96%AE/toc488Please respect copyright.PENANAmdAmOIQ0Ka
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同時亦可以在Penana網站裡按「買一嚿/半嚿薯仔」,以課金的方式推動我繼續搜羅資料寫文,多謝。488Please respect copyright.PENANAe62zcrFPxK
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Link:488Please respect copyright.PENANAQTAe555BQl
https://www.penana.com/user/27349/%E8%96%AF%E4%BB%94%E8%81%9E%E8%8C%B1%E8%8E%89/portfolio488Please respect copyright.PENANA7O1k7tStLY
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有興趣接收科學資訊的話,歡迎follow IG: potatopigtongue。488Please respect copyright.PENANANVq7yEsobb
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Ref1:https://www.nature.com/articles/s43018-020-009488Please respect copyright.PENANAlpG6RRoQNx