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。579Please respect copyright.PENANAzSBC34vmbR579Please respect copyright.PENANAkyrp5l6nXq
579Please respect copyright.PENANAuOifR0MoXZ
三十秒科學–腫瘤的周遭環境579Please respect copyright.PENANA1qPqo9x5tG
https://lih.kg/gFPfPS579Please respect copyright.PENANA1DHUXlcVp2
579Please respect copyright.PENANAnLsM1dkttk
三十秒科學–癌細胞嗜糖的原因579Please respect copyright.PENANAtnR7xGxiL8
https://lih.kg/2416199579Please respect copyright.PENANAaKl1JRFQow
579Please respect copyright.PENANAQ60wCiHNXp
今集我們會講述缺氧對癌細胞自身發展的其中一道好處。579Please respect copyright.PENANAb5izAcl6DM
579Please respect copyright.PENANAhFMQJ47gxF
(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。579Please respect copyright.PENANATL848ZZfg8579Please respect copyright.PENANAvortWHlRbA
579Please respect copyright.PENANAjSeeC0Nn6q
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)。579Please respect copyright.PENANACti3yQLDwm
579Please respect copyright.PENANAMLLoCIIwEG
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。579Please respect copyright.PENANAH7g7l66k55
579Please respect copyright.PENANAYigaziwhe5
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。579Please respect copyright.PENANAydrGyUbuyG
579Please respect copyright.PENANACDyTAzu9Sr
(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。579Please respect copyright.PENANAc4z4l4b07a579Please respect copyright.PENANAIpRrWnxnsW
579Please respect copyright.PENANAtzzZ80Rc60
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。579Please respect copyright.PENANA3V6O2usiVm
579Please respect copyright.PENANAmORPAFhBtT
(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。579Please respect copyright.PENANAFkAzMS2KWs
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。579Please respect copyright.PENANABfFbjtxmI7579Please respect copyright.PENANAXIFja87B5G
579Please respect copyright.PENANAjS2nqdnkWc
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。579Please respect copyright.PENANA8XML5Om0Mv
579Please respect copyright.PENANAo6cf6gycp1
(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。579Please respect copyright.PENANAQiL9l4R5rL
579Please respect copyright.PENANAXoRy5OUof8
579Please respect copyright.PENANA2YsFIkIyZk
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。579Please respect copyright.PENANAbXdAF6y91V
579Please respect copyright.PENANAzfEQt6Y1lZ
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。579Please respect copyright.PENANArmegpjTbWq
579Please respect copyright.PENANAk2NLoxprn4
那些不塗防曬便與陽光玩遊戲的人,一直是在玩命。579Please respect copyright.PENANA0Plc1NbAUG
579Please respect copyright.PENANAel0ySjtfv9
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。579Please respect copyright.PENANAcLgEmVxbry
579Please respect copyright.PENANAp5WPzHxVov
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/toc579Please respect copyright.PENANApRqhHZ1RsK
579Please respect copyright.PENANA4bkHxNWXKi
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。579Please respect copyright.PENANAw5mFUcnbCt
579Please respect copyright.PENANACuA0FNEVrl
Link:579Please respect copyright.PENANABUqKsWjzGr
https://www.penana.com/user/27349/%E8%96%AF%E4%BB%94%E8%81%9E%E8%8C%B1%E8%8E%89/portfolio579Please respect copyright.PENANA5wp2N3mo1u
579Please respect copyright.PENANAWHvN3vOgiG
579Please respect copyright.PENANA7qJqp1lO5u
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。579Please respect copyright.PENANARoUQ0FPhdr
579Please respect copyright.PENANACEjKSOCAZa
Ref1:https://pubmed.ncbi.nlm.nih.gov/8538748/579Please respect copyright.PENANAE6AymtbCXf