上兩集簡述了癌細胞缺氧的成因,以及缺氧導致癌細胞相對上更為依賴葡萄糖作新陳代謝用途。597Please respect copyright.PENANAxMvpsTDHQL597Please respect copyright.PENANAYnojD6qd7X
597Please respect copyright.PENANAJhleCnCGgd
三十秒科學–腫瘤的周遭環境597Please respect copyright.PENANAIbkVEOmVLz
https://lih.kg/gFPfPS597Please respect copyright.PENANA4331U5t1v6
597Please respect copyright.PENANAT34UBUGfG2
三十秒科學–癌細胞嗜糖的原因597Please respect copyright.PENANA6QzJsbEPrs
https://lih.kg/2416199597Please respect copyright.PENANAfhsxKRXJEt
597Please respect copyright.PENANArakLRttEPA
今集我們會講述缺氧對癌細胞自身發展的其中一道好處。597Please respect copyright.PENANAYmty2mQYfs
597Please respect copyright.PENANAti6PczN41B
(圖2)當DNA出現異變的時候,細胞裡名為p53的蛋白質便會出手幫忙,號令細胞停止生長(Cell cycle arrest),給予時間讓其他蛋白質幫忙協助修復DNA。597Please respect copyright.PENANADgo0GeWtDy597Please respect copyright.PENANAdxesCCheSx
597Please respect copyright.PENANAAYTRFVDJmw
若果細胞最後還是無法處理修復DNA的工作,p53便會指示細胞趨向死亡程序(Apoptosis)。597Please respect copyright.PENANA7yy37OfHMJ
597Please respect copyright.PENANAzc7LdEfmfA
腫瘤的出現,是無數DNA變異得出來的成果。因此在這方面來看,p53是防止癌細胞出現的好幫手,因為p53會確保細胞的DNA不會出現變異,或指令出現DNA變異的細胞消失。597Please respect copyright.PENANAQn1bvdFJLz
597Please respect copyright.PENANAYyyhkex7q0
但是,有一點非常矛盾的是,大部份普通細胞的p53蛋白質表達率非常低,它能否防止癌細胞出現這一點使人存疑。597Please respect copyright.PENANASTmHOm2w0M
597Please respect copyright.PENANASKjoVvFVr3
(圖3)事實上,非常諷刺的是,氧氣含量越低的話,P53蛋白質的表達率便會越高。597Please respect copyright.PENANAdrLqNt3UGi597Please respect copyright.PENANAPOWfyG9dHG
597Please respect copyright.PENANA9EdKsRujW6
而在缺氧的環境下,擁有p53的蛋白質的細胞便會自動進行死亡。597Please respect copyright.PENANAx7N9BaKAiO
597Please respect copyright.PENANAa2aHacoH3h
(圖4)重大的問題是,有部份缺氧的癌細胞會發展出變異版本的p53,失去原有的功能。597Please respect copyright.PENANAalRhVLrlw1
在缺氧施加的壓力下,擁有正常p53版本的細胞會一一死去,變相幫忙篩選出擁有變異版本p53的細胞,使它們逐漸成為大多數。597Please respect copyright.PENANAmEpMdLmaLQ597Please respect copyright.PENANAGQddWog4C4
597Please respect copyright.PENANAYIklxN2DTS
而這些擁有變異版本p53的細胞,修復DNA的能力會大幅度被削弱,因而加劇了DNA變異速度,促成腫瘤繼續長大。597Please respect copyright.PENANAmvUXksj92S
597Please respect copyright.PENANAxPxFWEoezq
(圖5)圖中為腫瘤形成的其中一道概論,癌細胞自製的缺氧環境,變相提供了一道挑選擁有更強DNA變異能力細胞的環境。597Please respect copyright.PENANAKD0mHosfar
597Please respect copyright.PENANARmb6isixVy
597Please respect copyright.PENANAOlXyUudFlH
現實中大部分的的癌細胞均擁有p53變異,而擁有p53變異的細胞更具抵抗化療藥物cis-platin的能力。597Please respect copyright.PENANAb6t5cA6Roy
597Please respect copyright.PENANAS9NQpbkklU
除缺氧外,大陽的紫外光亦是促使p53變異的好幫手,不少皮膚癌細胞均出現至少一處的p53變異。597Please respect copyright.PENANAFrNOexmnLB
597Please respect copyright.PENANAOrQIahecaR
那些不塗防曬便與陽光玩遊戲的人,一直是在玩命。597Please respect copyright.PENANAkddMnVTKhy
597Please respect copyright.PENANAF5tCL9fGil
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。597Please respect copyright.PENANAAIw1S0ovoD
597Please respect copyright.PENANAKjOkpuQ3BE
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/toc597Please respect copyright.PENANAfEMQPX7NrT
597Please respect copyright.PENANA7liJnzMsdF
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。597Please respect copyright.PENANAtQhkuByseI
597Please respect copyright.PENANAkX3j3ZdZXN
Link:597Please respect copyright.PENANA5T4jBxXf8c
https://www.penana.com/user/27349/%E8%96%AF%E4%BB%94%E8%81%9E%E8%8C%B1%E8%8E%89/portfolio597Please respect copyright.PENANAHhyLyAsyRI
597Please respect copyright.PENANAL69qfCN8ES
597Please respect copyright.PENANAhBqECSzXPv
除非Facebook及IG重開侵侵的account,否則我的IG將不會再作更新,只會寄居本土LIHKG及Penana。597Please respect copyright.PENANAcr72zEBPPI
597Please respect copyright.PENANAaNU76BSj8K
Ref1:https://pubmed.ncbi.nlm.nih.gov/8538748/597Please respect copyright.PENANA2VcT8Vy9T6