A class of anticancer medications known as topoisomerase I inhibitors targets an important enzyme involved in DNA replication and repair. These inhibitors function by disrupting the activity of topoisomerase I, which causes a build-up of breaks in DNA strands and, in the end, causes cancer cells that are proliferating quickly to die. Stabilization of the cleavage complex generated by topoisomerase I and DNA is one of the main mechanisms by which topoisomerase I inhibitors work against cancer. Normally, during processes like transcription and replication, topoisomerase I releases torsional strain by momentarily disrupting one strand of the DNA double helix. This allows the DNA to unwind. Topoisomerase I inhibitors, on the other hand, stop these DNA breaks from closing, which causes a build-up of damage to DNA and the start of apoptosis in cancer cells. Among the most well-known and frequently utilized topoisomerase I inhibitors are camptothecin and its derivatives, including irinotecan and topotecan of course. Numerous malignancies, including as lung, ovarian, and colorectal tumors, have been effectively treated with these medications. For instance, iminotecan is frequently included in combination chemotherapy regimens for colorectal cancer and has demonstrated efficacy when used as a first- and second-line treatment. Topoisomerase I inhibitors can have serious side effects even though they work well. Common side effects include gastrointestinal toxicity, myelosuppression, and, in the case of irinotecan, potentially fatal diarrhea. New formulations and combination medicines have been developed as a result of efforts to reduce these side effects and raise the therapeutic index of topoisomerase I inhibitors. Topoisomerase I inhibitors have been studied for their possible application in treating viral infections and autoimmune diseases in addition to their role as anticancer medicines. Investigations into these inhibitors' methods of action and resistance continue to yield important information about the biology of cancer and the creation of cutting-edge treatment approaches.To sum up, topoisomerase I inhibitors are a significant family of anticancer medications that have been shown to be effective in treating a variety of cancers. Notwithstanding the toxicities they are linked to, these agents remain indispensable in the oncologist's toolbox and have the potential to enhance cancer treatment even further.
