What happens when you inhibit topoisomerase?
Topoisomerase inhibitors block the ligation step of the cell cycle, which generates DNA single- and double-strand breaks, leading to apoptotic cell death. Topoisomerase I inhibitors include irinotecan, topotecan, and camptothecin, and topoisomerase II inhibitors include etoposide, doxorubicin, and epirubicin.
Does bleomycin inhibit topoisomerase?
Antitumor antibiotics or topoisomerase inhibitors include doxorubicin, daunorubicin, epirubicin, idarubicin, mitoxantrone, and bleomycin.
What happens if topoisomerase II is inhibited?
Inhibitors of topoisomerases I and II freeze these enzymes as protein-DNA complexes at various steps in their reaction pathways (31, 49). Topoisomerase-DNA-inhibitor complexes (cleavable complexes) are poisoned and are unable to execute a complete enzymatic cycle.
How does etoposide inhibit topoisomerase?
Etoposide kills cells by stabilizing a covalent enzyme-cleaved DNA complex (known as the cleavage complex) that is a transient intermediate in the catalytic cycle of topoisomerase II. If these breaks overwhelm the cell, they can initiate death pathways.
Why is vinblastine an effective anticancer drug?
How vinblastine works. Vinblastine works by stopping the cancer cells from separating into 2 new cells. So it blocks the growth of the cancer.
How does bleomycin cause pulmonary fibrosis?
The lung injury seen following bleomycin comprises an interstitial oedema with an influx of inflammatory and immune cells. This may lead to the development of pulmonary fibrosis, characterized by enhanced production and deposition of collagen and other matrix components.
How do topoisomerase II inhibitors work?
Inhibitors of the mammalian enzymes are widely used antitumor drugs. They stabilize topoisomerase-DNA cleavable complexes by hindering the DNA relegating step of the catalytic reaction, thus resulting in DNA cleavage stimulation.
