ABSTRACT
The development of targeted chemotherapeutic agents against colorectal cancer (CRC), one of the most common cancers with a high mortality rate, is in a constant need. Nannocystins are a family of myxobacterial secondary metabolites featuring a 21-membered depsipeptide ring. The in vitro anti-CRC activity of natural and synthetic nannocystins was well documented, but little is known about their in vivo efficacy and if positive, the underlying mechanism of action. In this study we synthesized a nitroaromatic nannocystin through improved preparation of a key fragment, and characterized its in vitro activity and in vivo efficacy against CRC. We first described the total synthesis of compounds 2-4 featuring Heck macrocyclization to forge their 21-membered macrocycle. In a panel of 7 cancer cell lines from different tissues, compound 4 inhibited the cell viability with IC values of 1-6 nM. In particular, compound 4 (1, 2, 4 nM) inhibited the proliferation of CRC cell lines (HCT8, HCT116 and LoVo) in both concentration and time dependent manners. Furthermore, compound 4 concentration-dependently inhibited the colony formation and migration of CRC cell lines. Moreover, compound 4 induced cell cycle arrest at sub-G1 phase, apoptosis and cellular senescence in CRC cell lines. In three patient-derived CRC organoids, compound 4 inhibited the PDO with IC values of 3.68, 28.93 and 11.81 nM, respectively. In a patient-derived xenograft mouse model, injection of compound 4 (4, 8 mg/kg, i.p.) every other day for 12 times dose-dependently inhibited the tumor growth without significant change in body weight. We conducted RNA-sequencing, molecular docking and cellular thermal shift assay to elucidate the anti-CRC mechanisms of compound 4, and revealed that it exerted its anti-CRC effect at least in part by targeting AKT1.
Subject(s)
Antineoplastic Agents , Cell Proliferation , Colorectal Neoplasms , Depsipeptides , Macrocyclic Compounds , Proto-Oncogene Proteins c-akt , Animals , Humans , Mice , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Apoptosis/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival/drug effects , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/pathology , Colorectal Neoplasms/metabolism , Depsipeptides/pharmacology , Depsipeptides/therapeutic use , Depsipeptides/chemistry , Depsipeptides/chemical synthesis , Drug Discovery , Drug Screening Assays, Antitumor , Proto-Oncogene Proteins c-akt/metabolism , Proto-Oncogene Proteins c-akt/antagonists & inhibitors , Structure-Activity Relationship , Xenograft Model Antitumor AssaysABSTRACT
The State Transition Equation (STE) based method to automatically generate the parallel CRC circuits for any generator polynomial or required amount of parallelism is presented. The parallel CRC circuit so generated is partially optimized before being fed to synthesis tools and works properly in our LAN transceiver. Compared with the cascading method, the proposed method gives better timing results and significantly reduces the synthesis time, in particular.