科普專欄–薯不揀單 - 分半鐘科學–缺氧對癌細胞的好處

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。829Please respect copyright.ＰＥＮＡＮＡ3GcRBxEu4T
829Please respect copyright.ＰＥＮＡＮＡVQ7Nyd7xfx
829Please respect copyright.ＰＥＮＡＮＡwaLV4u6hOB
三十秒科學–腫瘤的周遭環境829Please respect copyright.ＰＥＮＡＮＡFhbNXVSR8O
https://lih.kg/gFPfPS829Please respect copyright.ＰＥＮＡＮＡjJOEgMslPu
829Please respect copyright.ＰＥＮＡＮＡ8UasAcohDD
三十秒科學–癌細胞嗜糖的原因829Please respect copyright.ＰＥＮＡＮＡYWKZFXHeu3
https://lih.kg/2416199829Please respect copyright.ＰＥＮＡＮＡ9np0evmXeF
829Please respect copyright.ＰＥＮＡＮＡtLx8tLOtA7
今集我們會講述缺氧對癌細胞自身發展的其中一道好處。829Please respect copyright.ＰＥＮＡＮＡcEzKdzpimn
829Please respect copyright.ＰＥＮＡＮＡew51gwMR6j
（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。829Please respect copyright.ＰＥＮＡＮＡmhFDIajAT3
829Please respect copyright.ＰＥＮＡＮＡyfa946rdl5
829Please respect copyright.ＰＥＮＡＮＡxZck8tiSTp
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)。829Please respect copyright.ＰＥＮＡＮＡ00fNw6UerL
829Please respect copyright.ＰＥＮＡＮＡbbBzAK2pTa
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。829Please respect copyright.ＰＥＮＡＮＡvTQ3Ok82Gs
829Please respect copyright.ＰＥＮＡＮＡ0hrRUsve0V
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。829Please respect copyright.ＰＥＮＡＮＡyhNOpTgw5T
829Please respect copyright.ＰＥＮＡＮＡGDO29zJqoo
（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。829Please respect copyright.ＰＥＮＡＮＡwwi3TC5qIy
829Please respect copyright.ＰＥＮＡＮＡi3fF7GZ4vB
829Please respect copyright.ＰＥＮＡＮＡq52RtnJBSm
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。829Please respect copyright.ＰＥＮＡＮＡ0Samyyzinr
829Please respect copyright.ＰＥＮＡＮＡcbnk5n8Qe9
（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。829Please respect copyright.ＰＥＮＡＮＡ2VFAw9RfIB
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。829Please respect copyright.ＰＥＮＡＮＡFlo5MtHJdv
829Please respect copyright.ＰＥＮＡＮＡVbwFu5Qj7T
829Please respect copyright.ＰＥＮＡＮＡjwDxTGVjsm
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。829Please respect copyright.ＰＥＮＡＮＡ1CdAj5GASL
829Please respect copyright.ＰＥＮＡＮＡN5gle3l1GO
（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。829Please respect copyright.ＰＥＮＡＮＡo6DqzxR75r

829Please respect copyright.ＰＥＮＡＮＡz41YJYGc7O
829Please respect copyright.ＰＥＮＡＮＡmIfemNuQgb
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。829Please respect copyright.ＰＥＮＡＮＡhhKBQz378u
829Please respect copyright.ＰＥＮＡＮＡJvy7cb6s4C
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。829Please respect copyright.ＰＥＮＡＮＡEC8f6vYlUB
829Please respect copyright.ＰＥＮＡＮＡ3dl1BMAzJm
那些不塗防曬便與陽光玩遊戲的人，一直是在玩命。829Please respect copyright.ＰＥＮＡＮＡ8zQzecchWo
829Please respect copyright.ＰＥＮＡＮＡMDdWcjtykV
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。829Please respect copyright.ＰＥＮＡＮＡiNseAoKD8u
829Please respect copyright.ＰＥＮＡＮＡbQxXmMFEmW
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/toc829Please respect copyright.ＰＥＮＡＮＡjd4dwPv7YM
829Please respect copyright.ＰＥＮＡＮＡ95BHiIl5w5
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。829Please respect copyright.ＰＥＮＡＮＡ63yxrTKltR
829Please respect copyright.ＰＥＮＡＮＡOWGDnxW2iq
Link:829Please respect copyright.ＰＥＮＡＮＡCgIDnRUp0n
https://www.penana.com/user/27349/%E8%96%AF%E4%BB%94%E8%81%9E%E8%8C%B1%E8%8E%89/portfolio829Please respect copyright.ＰＥＮＡＮＡo0ehRPnsDx
829Please respect copyright.ＰＥＮＡＮＡMSywFR9nvf
829Please respect copyright.ＰＥＮＡＮＡVMwokA6Z7G
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。829Please respect copyright.ＰＥＮＡＮＡuiE64cEowm
829Please respect copyright.ＰＥＮＡＮＡiL357kdnuG
Ref1:https://pubmed.ncbi.nlm.nih.gov/8538748/829Please respect copyright.ＰＥＮＡＮＡ5nqOLjRUW5

ns216.73.216.217da2

Reading Theme:

Font Size:

Line Spacing:

Paragraph Spacing:

Load the next issue automatically