以免疫治療(Immunotherapy)手段醫治癌症,絕對是人類在醫學界踏出的「月球一小步」;2131Please respect copyright.PENANAz7tycjSwdn
2018年的醫學諾貝爾得獎者,亦是因為對免疫治療方面作出了無比重要的貢獻因而獲獎。2131Please respect copyright.PENANA8gbEpstAqH
2131Please respect copyright.PENANACuX6q8sNT1
對比傳統的化療,免疫治療不但不會引起脫髮等副作用,病人的存活率更會比傳統化療的顯著為長,但略為遺憾的是並不是所有人及所有的癌症也能從免疫治療中獲益。2131Please respect copyright.PENANAUFZ4ocyIlY
2131Please respect copyright.PENANA4Rs5Mak61V
今次的深入淺出,將會為大家講解免疫治療的原理及解釋箇中的好處。2131Please respect copyright.PENANAC6Pikf63DX
2131Please respect copyright.PENANAGXx8JT8MrH
(圖1)正常細胞(Normal Cell)進行繁殖的時候,無可避免會出現DNA變異。我們的細胞雖有著完善的機制可即時修正錯誤,但隨著年紀歲數的增長,修正DNA錯誤的效率亦會相對減低,最終造就DNA出現變異。2131Please respect copyright.PENANAN0DlOMjxHa2131Please respect copyright.PENANAK9coWlYxo7
2131Please respect copyright.PENANAJV1Uagumm1
而當細胞DNA出現變異後,我們的免疫細胞T cell會將其視作為外來物,把變異細胞殲滅。2131Please respect copyright.PENANAH8NXbWhLSY
2131Please respect copyright.PENANAWO6yIpq5yP
可是,若然變異細胞發展出躲避免疫系統的機制,而又累積一定程度的基因變異,便會獲得無驅無束般繁殖的能力,形成腫瘤。2131Please respect copyright.PENANAIaxmuJQGSU
2131Please respect copyright.PENANAshGXQTKgQw
(圖2)癌細胞躲避免疫系統機制的方法有很多種,較為常見的是PD1(Programmed cell death protein1)系統。2131Please respect copyright.PENANAefkKbZK7142131Please respect copyright.PENANAzYrmCfO1yU
2131Please respect copyright.PENANApQQ4JGzPsY
2131Please respect copyright.PENANA5qhFD27esj
我們的T cell會依靠癌細胞與別不同的蛋白質(Neoantigen)來作出辨認,並將變異細胞殲滅。2131Please respect copyright.PENANAC1hFG4Milv
2131Please respect copyright.PENANA37Z1whACRz
但是若果變異細胞的表面產生名為PDL1的蛋白質,它便能夠與T Cell的PD1作出合併,因此觸發一系列的機制,大幅度銳弱T cell殺滅變異細胞的能力,導致T cell再也不能消滅自己。2131Please respect copyright.PENANADdYrL5Wuhk
2131Please respect copyright.PENANAYVtk9C259T
形象化的來說,若果癌細胞穿上「我愛警察」的衣服(PDL1)後,擁有PD1警棍的黑警便會立刻手軟,放生癌細胞離開,讓癌細胞繼續任意妄為。2131Please respect copyright.PENANA8SNhBGnZ28
2131Please respect copyright.PENANAjk0N7WZ2Hx
換句話說,癌細胞只要能夠產生PDL1,就能夠逃避T cell的追捕及殺滅;2131Please respect copyright.PENANANe8Gbs0NYP
相對上,皮膚癌及肺癌的癌細胞較大機會出現PDL1。2131Please respect copyright.PENANAbP2MmPbM06
2131Please respect copyright.PENANAU44wmjSrma
2131Please respect copyright.PENANAXWdBA5aEQY
(圖3)既然了解得到PDL1/PD1的關係,那麼對付的方法顯然變得非常簡單,只要把對應的抗體送到體內,阻截PDL1及PD1合併便可。2131Please respect copyright.PENANAV9zxCFe4lU
2131Please respect copyright.PENANA7TBmsjXD6y2131Please respect copyright.PENANAiycmRZMqwC
2131Please respect copyright.PENANAEVtli3i7Yu
以下為現今運用在治療中及臨床研究中的抗體整理。2131Please respect copyright.PENANAHPn0rtGIya
2131Please respect copyright.PENANAjn9m9LRrlS
阻擋PD1的抗體:2131Please respect copyright.PENANANJTsTgE2ek
1.Nivolumab (FDA approved)2131Please respect copyright.PENANAdguXt1tRt5
2.Pembrolizumab (FDA approved)2131Please respect copyright.PENANAEEih9Pwi9M
3.Pidilizumab2131Please respect copyright.PENANAB4ekcCtNY8
4.MEDI-06802131Please respect copyright.PENANABCPVBpu2uM
4.PDR0012131Please respect copyright.PENANAHjRtrQlrsg
5.REGN28102131Please respect copyright.PENANATqbNVFIQ3q
2131Please respect copyright.PENANAqq1OkzpdYg
阻擋PDL1的抗體:2131Please respect copyright.PENANAelsEf0aONr
1.Atezolimumab2131Please respect copyright.PENANA3KHBtjCTKe
2.Durvalumab2131Please respect copyright.PENANA8aXgkvpugb
3.Avelumab2131Please respect copyright.PENANAyDsHZepGHp
4.MDX-11052131Please respect copyright.PENANA6BcbgmYkMs
2131Please respect copyright.PENANARZavPdLGqo
2131Please respect copyright.PENANAEddVciYSG2
簡單來說,就是利用抗體來阻截PD1/PDL1,促使癌細胞無法逃避免疫細胞的追捕,被迫接收免疫細胞的制裁。2131Please respect copyright.PENANAdHGpf1Kc3P
2131Please respect copyright.PENANApQcRsnLRR3
2131Please respect copyright.PENANAAhoHKOQxSj
(圖4)為突顯Immunotherapy(免疫系統治療)的好處,我們可以找一個Chemotherapy(化療)的例子作出比較。2131Please respect copyright.PENANAinMbmfXj2F2131Please respect copyright.PENANA3SG4ihkbm4
2131Please respect copyright.PENANAagd0lwdOTZ
針對癌細胞出現X變異,我們便用上針對X變異的化療藥物醫治。2131Please respect copyright.PENANAbHqwBFwWcc
2131Please respect copyright.PENANAy7eRv4Ocl5
在初期,此方法可能會有奇效,但是隨著時間推進,沒有死去的話癌細胞便會發展出不同抗藥機制,導致藥物失效。2131Please respect copyright.PENANAQyVcfQlWj6
2131Please respect copyright.PENANArXuGJ9z8sa
譬如說,X變異變成Y變異,導致只針對X變異的藥物再也沒能針對自己。2131Please respect copyright.PENANAYKbrv0YTLA
2131Please respect copyright.PENANAusLN5CfdwK
又或者,癌細胞會產生蛋白質將藥物帶出細胞外,現今有著不同真實例子顯示出還有各種不同的機制,在這裡不便詳列。2131Please respect copyright.PENANACHQbFVLUDE
2131Please respect copyright.PENANAvIgeG3ihSN
(圖5)但是,在免疫系統治療方面來說,無論癌細胞如何變異也好,它們始終亦會被T cell界定為外來之物,成為被殲滅的目標。2131Please respect copyright.PENANAEvMuxfT4CA
甚之乎,越多的變異反而會更容易令T cell被認出為外來之物,更易被成為T cell的目標。2131Please respect copyright.PENANAe6PSWKLJI2
2131Please respect copyright.PENANAfMGdgpPmd92131Please respect copyright.PENANA9OXNdZqChB
2131Please respect copyright.PENANAj0lOsAheU8
在這裡,我們可以看得出免疫治療的精髓所在。2131Please respect copyright.PENANAL61yA2d2uv
2131Please respect copyright.PENANAnvYaQHvWux
免疫治療的方針並不是在針對癌細胞自身,而是針對癌細胞逃避免疫系統細胞的機制。2131Please respect copyright.PENANAxnIE7lHqs2
2131Please respect copyright.PENANAJWsILCRZkU
在此,我們只是讓免疫系統回復正常運作,糾正它們懂得把癌細胞辨認為外來物,並把外來物消除。2131Please respect copyright.PENANAj18Gaboq6S
2131Please respect copyright.PENANA3C94DKkD3F
這方法根本上沒有額外改動身體的機制,有部份病人可能會出現輕微作嘔感覺,但大部份人士並不會遭受脫髮、食慾不振、手軟腳軟、血球細胞出現問題等等會在化療時候遭受得到的副作用!2131Please respect copyright.PENANASGtR1aTXid
2131Please respect copyright.PENANADzykUd0AAS
2131Please respect copyright.PENANAqs9gvfvvv9
只不過的是,普遍來說一整個免疫治療至少需要美金150,000才能進行,而且若然癌細胞並沒有產生大量PDL1的話,這方法亦不會太過有效。2131Please respect copyright.PENANAgwR5myYhcx
2131Please respect copyright.PENANADZnKWs9noD
對此,現時科學家亦研發出不同手段針對這個問題,若然大家對這話題有興趣的話,請正評以及回覆此Post,我會視乎反應寫出下集講解現時免疫治療的最新發展、成果及所面對著的問題。2131Please respect copyright.PENANAh6C4EI8W9h
2131Please respect copyright.PENANAbCqFfLlwsn
希望大家看完這篇文章後,會領略得到免疫治療的原理及與化療手段的根本性分別。2131Please respect copyright.PENANAVuMtmDiNko
2131Please respect copyright.PENANALn6WJhrERp
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。2131Please respect copyright.PENANADFDlIzCkda
2131Please respect copyright.PENANAZuCBoY2kTg
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/toc2131Please respect copyright.PENANADlMpsoumJ3
2131Please respect copyright.PENANAjchNExOgev
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。2131Please respect copyright.PENANAFaaj2zRFI9
2131Please respect copyright.PENANAxywPEyfPx6
Link:2131Please respect copyright.PENANA8hXouCYmja
https://www.penana.com/user/27349/%E8%96%AF%E4%BB%94%E8%81%9E%E8%8C%B1%E8%8E%89/portfolio2131Please respect copyright.PENANAmTBJ42AhMs
2131Please respect copyright.PENANAfH1GIR0VbF
2131Please respect copyright.PENANAMGzIJY5cmR
有興趣接收科普資訊的話,歡迎follow IG: potatopigtongue。2131Please respect copyright.PENANAqzZ2w3UT6Q