This is how cyclopeptides help cancer cells proliferate

An international team led by scientists from the Israel Institute of technology has found out how cyclopeptides inhibit cancer and promote protein decomposition, thus promoting the growth and reproduction of cancer cells The researchers believe that the strategy they developed will pave the way for a new anti-cancer therapy based on cyclopeptides This research achievement is regarded as a milestone in the application of ubiquitin system, and relevant papers are published in the latest journal of nature chemistry Scientists in Israel and the United States have previously found that ubiquitin (or ubiquitin protein) can mark defective proteins with "death marks" and make them decompose under the action of protease, thus winning the Nobel Prize in chemistry in 2004 Ubiquitin system is essential for the health of organism The interruption of ubiquitin system will cause various cancers, amyotrophic lateral sclerosis, cystic fibrosis, Parkinson's disease and other neurodegenerative diseases At present, ubiquitin research plays a key role in understanding and treating the cell division process of a certain type of cancer The first stage of normal activity of ubiquitin system is to produce ubiquitin chain, which then marks the protein to be decomposed However, as cancer develops in the body, cancer cells know how to operate in the ubiquitin system to maintain their own survival and proliferation The strategy developed by the team led by Professor Ashraf brick, director of cyclopeptide anticancer research, Israel Institute of technology, aims to counteract the ability of malignant tumors to operate in the ubiquitin system, which is based on the combination of ubiquitin chain chemical production technology and large cyclopeptide molecular library In the study, they found how cyclopeptides bind to ubiquitin chains, preventing ubiquitin from properly labeling cancer promoting proteins, thereby inhibiting their breakdown The team said that they used highly uniform ubiquitin chains obtained by chemical synthesis of protein technology to screen trillions of molecules in a large cyclopeptide library, and found and confirmed new cyclopeptides that can closely bond with the ubiquitin chain of K48 These cyclopeptides protect the K48 linked ubiquitin chain from the influence of de ubiquitinase and prevent the ubiquitin labeled protein from being degraded by protease Professor brick said that the progress of ubiquitin system application research and related drug development is very slow The team believes that a highly synthetic method with the ability of in vitro protein target generation and cyclopeptide discovery will allow other well-developed targets to be used for drug discovery and pave the way for the development of new cyclopeptide based anticancer therapies.