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。477Please respect copyright.PENANAf2kNIsQec4477Please respect copyright.PENANAV2rhMIy66B
477Please respect copyright.PENANAye3kD2qq4N
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。477Please respect copyright.PENANA8D0SPspfni
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。477Please respect copyright.PENANAPU51GvNPjW
477Please respect copyright.PENANAEGZU3RK52T
(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。477Please respect copyright.PENANAWApEPbNOLp477Please respect copyright.PENANAKXTZtt1Cmn
477Please respect copyright.PENANAV94Bxk0bcj
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。477Please respect copyright.PENANA40MQkFQu47
477Please respect copyright.PENANApXMhOpJVyl
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)。477Please respect copyright.PENANARZ5NlOYDDR
477Please respect copyright.PENANAyYS4TCfGjn
(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。477Please respect copyright.PENANA8IoObDVI5C477Please respect copyright.PENANAm0KlpoyQiV
477Please respect copyright.PENANAZGLDbs3dGg
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。477Please respect copyright.PENANAUP4hdw5Lre
477Please respect copyright.PENANAn5MwSTqy1u
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。477Please respect copyright.PENANAwudMyf0wB1
477Please respect copyright.PENANATnKmBKnWZa
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。477Please respect copyright.PENANAo8COQefziT
477Please respect copyright.PENANAhlfkkshPj9
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。477Please respect copyright.PENANAZtVCHTfebG
477Please respect copyright.PENANAGiwIrCT9RA
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。477Please respect copyright.PENANARFbb9w1XxI
477Please respect copyright.PENANAg3rGICHmoT
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。477Please respect copyright.PENANA1y0QSNBRaG
477Please respect copyright.PENANAmJ1imCoMjw
477Please respect copyright.PENANAqu4I3lTUvB
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。477Please respect copyright.PENANAkR4unfoJ9x
477Please respect copyright.PENANApg4QoyPZnP
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/toc477Please respect copyright.PENANAIb5vlkZyJU
477Please respect copyright.PENANAIIShmlBPbM
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。477Please respect copyright.PENANABRZviVLwns
477Please respect copyright.PENANAX8wdb8TYxY
Link:477Please respect copyright.PENANAmUHcn9fysJ
https://www.penana.com/user/27349/%E8%96%AF%E4%BB%94%E8%81%9E%E8%8C%B1%E8%8E%89/portfolio477Please respect copyright.PENANAcOlck9UhYy
477Please respect copyright.PENANAslpX6L3Spt
有興趣接收科學資訊的話,歡迎follow IG: potatopigtongue。477Please respect copyright.PENANAkG2AohJ999
477Please respect copyright.PENANAkYa1uQqQQo
https://www.instagram.com/potatopigtongue/477Please respect copyright.PENANAinfsY42jaC
477Please respect copyright.PENANAYPexOqX0b6
477Please respect copyright.PENANAAzTls2jgxH
Ref1:https://www.nature.com/articles/s42255-020-0253-2