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。610Please respect copyright.PENANAM9tGg6t1Tk610Please respect copyright.PENANAGedQeRDhb5
610Please respect copyright.PENANA5AIXLFDOgg
三十秒科學–腫瘤的周遭環境610Please respect copyright.PENANAw05Q0FCmfp
https://lih.kg/gFPfPS610Please respect copyright.PENANAiucekj1Awb
610Please respect copyright.PENANAcFHLGGL95S
三十秒科學–癌細胞嗜糖的原因610Please respect copyright.PENANAlPH3IMS5O3
https://lih.kg/2416199610Please respect copyright.PENANAVgpIG2N3vr
610Please respect copyright.PENANAhJ6EBhSqo5
今集我們會講述缺氧對癌細胞自身發展的其中一道好處。610Please respect copyright.PENANAUwNTZGTK9u
610Please respect copyright.PENANAQSzdCscE51
(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。610Please respect copyright.PENANAgjda6nIovy610Please respect copyright.PENANAWeQKAO3QwS
610Please respect copyright.PENANAzJEPAHotEf
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)。610Please respect copyright.PENANAY2H0nIdYwk
610Please respect copyright.PENANATKtDj0CkJg
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。610Please respect copyright.PENANAvZNMzhPxSW
610Please respect copyright.PENANAcM1AUIalJZ
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。610Please respect copyright.PENANAFjneiu4Hhg
610Please respect copyright.PENANAU8fiSfhaOL
(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。610Please respect copyright.PENANATZnW6FlBjc610Please respect copyright.PENANAVf5ReU5NH1
610Please respect copyright.PENANA1xGv0zNSrd
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。610Please respect copyright.PENANAqYGnpfDGUx
610Please respect copyright.PENANAklT20oWV6p
(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。610Please respect copyright.PENANAYVR2FCfS6m
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。610Please respect copyright.PENANAp0m7Rcn7pJ610Please respect copyright.PENANAzWfchatkYX
610Please respect copyright.PENANAQZZqGlMasO
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。610Please respect copyright.PENANAykwvyehTpY
610Please respect copyright.PENANAQafrrbsXcG
(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。610Please respect copyright.PENANAPmbxSKekZr
610Please respect copyright.PENANA1IQEH8HxPA
610Please respect copyright.PENANA8JduX2GzhY
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。610Please respect copyright.PENANA2TW94LAXx5
610Please respect copyright.PENANA11ENVCNq9m
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。610Please respect copyright.PENANA5KUamdwhPn
610Please respect copyright.PENANABQdaH3RGWr
那些不塗防曬便與陽光玩遊戲的人,一直是在玩命。610Please respect copyright.PENANATto6rWnRBE
610Please respect copyright.PENANAHwGiGc8Yno
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。610Please respect copyright.PENANA2vixXF3KCr
610Please respect copyright.PENANAVPOaAmKz7c
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/toc610Please respect copyright.PENANAMZCehPAPj5
610Please respect copyright.PENANANeHkizPuza
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。610Please respect copyright.PENANAcAL3MqEHK0
610Please respect copyright.PENANAvWNrvAVQgG
Link:610Please respect copyright.PENANAnnfeqGr4Z7
https://www.penana.com/user/27349/%E8%96%AF%E4%BB%94%E8%81%9E%E8%8C%B1%E8%8E%89/portfolio610Please respect copyright.PENANAG4sGQbQ9ES
610Please respect copyright.PENANAVXgdt0QQZS
610Please respect copyright.PENANAVCFQ8SDuJG
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。610Please respect copyright.PENANAJiuidgyAbN
610Please respect copyright.PENANAO7rG54oexe
Ref1:https://pubmed.ncbi.nlm.nih.gov/8538748/610Please respect copyright.PENANAx6ljlrbz15