“…As a result, the structural and functional studies on Top I have provided a reliable platform for the development of Top I inhibitors, which block the DNA synthesis and malignant cell proliferation during many pivotal cellular processes such as transcriptions, replication, chromosome condensation, and are considered as important antineoplastic chemotherapeutic agents with the mechanism of DNA interaction1920. In clinic, Top I inhibitors have been successfully applied for the treatment of colorectal, lung and ovarian cancers nowadays21, such as camptothecin (CPT) families, particularly the two CPT derivatives topotecan (TPT) and irinotecan (IFL), the only two Top I inhibitors approved by the FDA for the treatments of ovarian, colorectal and lung cancer, have displayed significant anticancer effects192223.…”