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。380Please respect copyright.PENANA1XsXE46189
380Please respect copyright.PENANAz7anNVtEkO
380Please respect copyright.PENANAkh4lmhzIwD
三十秒科學–腫瘤的周遭環境380Please respect copyright.PENANAWuFVfrJM6o
https://lih.kg/gFPfPS380Please respect copyright.PENANAWShz5hC49D
380Please respect copyright.PENANA1Iv8NtPii4
三十秒科學–癌細胞嗜糖的原因380Please respect copyright.PENANAbKPTVCYPdN
https://lih.kg/2416199380Please respect copyright.PENANAnuFADgwoQo
380Please respect copyright.PENANAmqvD0lHo0U
今集我們會講述缺氧對癌細胞自身發展的其中一道好處。380Please respect copyright.PENANA2uzd6jDviC
380Please respect copyright.PENANALpwN2pUcgT
(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。380Please respect copyright.PENANAoSWqTDnoxk
380Please respect copyright.PENANAOauDMFbO7g
380Please respect copyright.PENANA1RXctOIX2R
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)。380Please respect copyright.PENANA7virpiKhMJ
380Please respect copyright.PENANAIy0Uyidqb0
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。380Please respect copyright.PENANADg47yGRhSQ
380Please respect copyright.PENANA05JH4bjC1L
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。380Please respect copyright.PENANAV5KMAP5pcs
380Please respect copyright.PENANAIRWXPkqNn7
(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。380Please respect copyright.PENANAurbPRjhnZn
380Please respect copyright.PENANAgDDb1Z2kjz
380Please respect copyright.PENANAU4fsjq24e5
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。380Please respect copyright.PENANAR8VLqOqBvL
380Please respect copyright.PENANAKf6UIkq9xW
(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。380Please respect copyright.PENANAH6F5dx59sX
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。380Please respect copyright.PENANAzEvpBL2uGt
380Please respect copyright.PENANAOvK6WPD1hW
380Please respect copyright.PENANAbLAlXzRPkK
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。380Please respect copyright.PENANAsNMAhwE0J5
380Please respect copyright.PENANA1PHvaOwWhO
(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。380Please respect copyright.PENANAMcOfvzRILb
380Please respect copyright.PENANAKWCiN1ppp1
380Please respect copyright.PENANAfYPbtuOtaw
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。380Please respect copyright.PENANAZ0QMqIRi7v
380Please respect copyright.PENANAGRUoQgOpYq
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。380Please respect copyright.PENANAJabCMsBP2y
380Please respect copyright.PENANAdza18VRdSH
那些不塗防曬便與陽光玩遊戲的人,一直是在玩命。380Please respect copyright.PENANAheWOPCCZf5
380Please respect copyright.PENANAmQqKtXjCLg
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。380Please respect copyright.PENANAVq7TqJcrdR
380Please respect copyright.PENANABcx14EOrMg
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/toc380Please respect copyright.PENANASm2EQ8SlzB
380Please respect copyright.PENANAdetOpNz4sM
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。380Please respect copyright.PENANAQfIiW9U14o
380Please respect copyright.PENANAR0kmrb9CGb
Link:380Please respect copyright.PENANAEqdcxT6ey8
https://www.penana.com/user/27349/%E8%96%AF%E4%BB%94%E8%81%9E%E8%8C%B1%E8%8E%89/portfolio380Please respect copyright.PENANA7cF5rWVC5R
380Please respect copyright.PENANALHYoLsRwDs
380Please respect copyright.PENANAXnbXKcFNsV
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。380Please respect copyright.PENANAV7BCxIguc5
380Please respect copyright.PENANAygmTgb8jWt
Ref1:https://pubmed.ncbi.nlm.nih.gov/8538748/380Please respect copyright.PENANA4BQ1djbfQl