7.抗癌藥物5-Fluorouracil經癌細胞代謝成5-FdUMP後,此代謝物可抑制下列何種酶,進而抑制DNA複製?
(A)Dihydrofolate reductase
(B)Hypoxanthine-guanine phosphoribosyltransferase
(C)Topoisomerase II
(D)Thymidylate synthase
答案:登入後查看
統計: A(580), B(244), C(107), D(2694), E(0) #415049
統計: A(580), B(244), C(107), D(2694), E(0) #415049
詳解 (共 10 筆)
#895482
Capecitabine、Fluoxuridine、 Tegafur為5-FU的前驅藥,同樣會抑制thymidylate synthase
5-FU有手口足症及骨髓抑制副作用; 產生抗藥性原因為癌症細胞降低對藥品的活性化
常用來治療乳房癌及大腸直腸癌
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3
#1426905
間接會直接抑制Thymidylate synthase稱為thymineless death。
直接抑制:5-FU
間接抑制:MTX、Trimethoprim,都是先抑制dihydrofolate reductase
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2
#1411940
5-FU產生抗藥性原因:Uridine kinase減少
45.下列何者為5-fluorouracil在癌細胞產生抗藥性的原因?
(A)癌細胞減低對藥品的攝取(uptake)
(B)癌細胞增加對藥品的排出(efflux)
(C)癌細胞減低對藥品的活性化(activation)
(D)癌細胞增加對藥品的不活性化(inactivation)
(A)癌細胞減低對藥品的攝取(uptake)
(B)癌細胞增加對藥品的排出(efflux)
(C)癌細胞減低對藥品的活性化(activation)
(D)癌細胞增加對藥品的不活性化(inactivation)
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1
#1242905
(A)Dihydrofolate reductase-Methotrexate
(B)Hypoxanthine-guanine phosphoribosyltransferase-6-Mercaptopurine
(C)Topoisomerase II-Quinolone、Doxorubicin、Bleomycin、Eptoside
(B)Hypoxanthine-guanine phosphoribosyltransferase-6-Mercaptopurine
(C)Topoisomerase II-Quinolone、Doxorubicin、Bleomycin、Eptoside
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1
#1099015
(B) 6-MP 必須進入目標細胞中並經由HGPRT 催化轉換成核苷酸衍生物6-thioinosinate 此衍生物具抗癌活性。
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0
#849084
Fluorouracil or 5-FU is a drug that is a pyrimidine analog which is used in the treatment of cancer. It is a suicide inhibitor and works through irreversible inhibition of thymidylate synthase. It belongs to the family of drugs called antimetabolites.
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#849087
Thymidylate synthase抑制dUMP變成dTMP 意志DNA thymine
6
2
#4957962
5-FU
| IV途徑 | 機轉 |
| Continuous iv infusion | 抑制thymidylate synthase |
| Intermittent iv bolus | 嵌入DNA |
(A)MTX
(B)6-MP
(C)-rubicin、bleomycin、podophyllotoxin類、FQs
0
0