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question

A Clinical Trial Of A New Chemotherapy Protocol Is Performed Involving Patients With Lung Carcinoma. It Is Observed That A Response Occurs That Leads To Dna Strand Breakage And Carcinoma Cell Death. The Primary Carcinomas Are Initially Observed To Decrease In Size Following Therapy. However, After 3 Months, The Carcinoma Is No Longer Regressing With This Therapy.

Altered Expression Of Which Of The Following By The Neoplastic Cells Has Most Likely Resulted In This Reduced Response?



A Vimentin

B Leukocyte Common Antigen

C Laminin Receptor

D Actin

E Dna Topoisomerase Ii

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answer / Explanation:

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(e) Correct.

This Is A Nuclear Enzyme Which Untangles Dna At The End Of Mitosis. The Drugs That Target Topoisomerase Ii Freeze The Enzyme As It Is Cutting Dna Strands. This Leads To Dna Strand Breakage And Cell Death. Resistant Cells In Culture Show Alterations In The Topoisomerase Ii Protein.
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