Belotecan is a drug used in

chemotherapy Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs (chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemother ...

. It is a semi-synthetic

camptothecin Camptothecin (CPT) is a topoisomerase inhibitor. It was discovered in 1966 by M. E. Wall and M. C. Wani in systematic screening of natural products for anticancer drugs. It was isolated from the bark and stem of '' Camptotheca acuminata'' (Campt ...

analogue indicated for

small-cell lung cancer Small-cell carcinoma is a type of highly malignant cancer that most commonly arises within the lung, although it can occasionally arise in other body sites, such as the cervix, prostate, and gastrointestinal tract. Compared to non-small cell ca ...

and

ovarian cancer Ovarian cancer is a cancerous tumor of an ovary. It may originate from the ovary itself or more commonly from communicating nearby structures such as fallopian tubes or the inner lining of the abdomen. The ovary is made up of three different ...

, approved in South Korea under the trade name Camtobell, presented in 2 mg vials for injection. The drug has been marketed by ChongKunDang Pharmaceuticals since 2003.

Mechanism of action

Belotecan blocks topoisomerase I with a pIC₅₀ of 6.56, stabilizing the cleavable complex of topoisomerase I-DNA, which inhibits the religation of single-stranded DNA breaks generated by topoisomerase I; lethal double-stranded DNA breaks occur when the topoisomerase I-DNA complex is encountered by the DNA replication machinery, DNA replication is disrupted, and the tumor cell undergoes apoptosis. Topoisomerase I is an enzyme that mediates reversible single-strand breaks in DNA during DNA replication.

References

Topoisomerase inhibitors Delta-lactams Delta-lactones Nitrogen heterocycles Oxygen heterocycles Heterocyclic compounds with 5 rings Isopropyl compounds {{antineoplastic-drug-stub