透過進食,我們能夠從食物中獲取身體所需的能量。這過程亦稱之為新陳代謝。516Please respect copyright.PENANAl7F0Oc7WnG516Please respect copyright.PENANAQWzPWwJ9fI
516Please respect copyright.PENANALkEWEb9huM
有無數證據顯示,癌細胞的新陳代謝與正常的細胞有著顯著的分別。516Please respect copyright.PENANAJcrYi4x0Db
正因如此,有不少科學家抱有一個信念,希望透過針對癌細胞的新陳代謝來抑止癌細胞的生長,甚至是達消滅癌細胞之效。516Please respect copyright.PENANAXI9yjjsVik
516Please respect copyright.PENANAPZrd193yOa
(圖2)半胱胺酸 (Cysteine)是氨基酸的一種,亦即是組成蛋白質的基本單元。516Please respect copyright.PENANAneTi2bBctN516Please respect copyright.PENANAW51ZqKU5Ar
516Please respect copyright.PENANAMFHrv7EDw8
我們可以透過直接進食來攝取Cysteine,又或者依靠肝臟將特定兩隻氨基酸(Methionine及Serine)轉化成為Cysteine供我們所用。516Please respect copyright.PENANAEAl2wtVokm
516Please respect copyright.PENANAfP178yM38m
有科學家嘗試從飼養癌細胞的營養液中剔除Cysteine,發覺部份癌細胞的生長速度有所減慢,而有部份的癌細胞則趨向死亡(Ref1)。516Please respect copyright.PENANAdA0IKTnFxe
516Please respect copyright.PENANAQaQRolRA0A
(圖3)從營養液剔除Cysteine後,身體攝取Cysteine的辦法便只剩下依靠肝臟將同為氨基酸的Methionine及Serine轉化成為Cysteine。516Please respect copyright.PENANAEqUpeCRhNn516Please respect copyright.PENANAX3TziUetHm
516Please respect copyright.PENANAy8PjKXZGbz
而各種剔除Cysteine便會死亡的癌細胞的共通點,就是缺乏一隻名為5-methylthioadenosine phosphorylase(MTAP)的蛋白酶。516Please respect copyright.PENANAGL9hk4nGjl
516Please respect copyright.PENANAIDhhneqLYN
失去MTAP後,細胞會傾向將Methionine轉化成為一系列名為Polyamine的物質,導致身體失去製作Cysteine的手段。516Please respect copyright.PENANAxLrCtyVmcx
516Please respect copyright.PENANABJp5QPsCTt
更甚的是,產生Polyamine的過程中將會產生游離基,而制衡游離基的Glutathione卻則依靠Cysteine作為原材料。516Please respect copyright.PENANAII9zaymHVT
516Please respect copyright.PENANAdmr8O3Y3SD
因此,缺乏MTAP的癌細胞若然沒有外來Cysteine供應的話,便會因游離基數量過多而導致死亡。516Please respect copyright.PENANAVSFKNiOgtN
516Please respect copyright.PENANAfikx89kLLw
環觀各種癌細胞,膠質母細胞瘤(Glioblastoma)有較大的機會因基因變異而失去MTAP基因。516Please respect copyright.PENANApygus8N0sW
516Please respect copyright.PENANAFWzj8iA6LB
根據上述研究結果,若癌症病人的癌細胞證實缺乏MTAP基因的話,在餐單中剔除進食Cysteine氨基酸或許是一個副作用相對上為微的理性選擇。516Please respect copyright.PENANAb2EP6NPgga
516Please respect copyright.PENANAPWWYEkw66z
516Please respect copyright.PENANAOvEylO19IN
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。516Please respect copyright.PENANAyKfnPXmOyv
516Please respect copyright.PENANApSmRW44wxj
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/toc516Please respect copyright.PENANAiW03ZkvGRU
516Please respect copyright.PENANARfzaM13J1V
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。516Please respect copyright.PENANAKdiOYZJCtp
516Please respect copyright.PENANApJxSzkmaey
Link:516Please respect copyright.PENANAA8uqkZVd9j
https://www.penana.com/user/27349/%E8%96%AF%E4%BB%94%E8%81%9E%E8%8C%B1%E8%8E%89/portfolio516Please respect copyright.PENANAzhVfLlFIqi
516Please respect copyright.PENANAbihJ641M7l
有興趣接收科學資訊的話,歡迎follow IG: potatopigtongue。516Please respect copyright.PENANAjTfzgBstYC
516Please respect copyright.PENANAlumNiKGT1c
https://www.instagram.com/potatopigtongue/516Please respect copyright.PENANAUnacylUXjl
516Please respect copyright.PENANAT6OEzyQRZU
516Please respect copyright.PENANAeGQYneehx8
Ref1:https://www.nature.com/articles/s42255-020-0253-2