1. Improving Selectivity, Proteolytic Stability, and Antitumor Activity of Hymenochirin-1B: A Novel Glycosylated Staple Strategy
Yulei Li, Yihan Zhang, Minghao Wu, Qi Chang, Honggang Hu, Xia Zhao ACS Chem Biol. 2019 Mar 15;14(3):516-525. doi: 10.1021/acschembio.9b00046. Epub 2019 Mar 1.
As a host defense peptide, hymenochirin-1B has attracted increasing attention for its strong cytotoxic activities. However, its poor selectivity and proteolytic stability remain major obstacles for clinical application. To solve these problems, we designed and synthesized a series of peptide analogues of hymenochirin-1B based on cationic residue substitution and stapling combined with a glycosylation strategy. Some analogues showed improvement not only in selectivity and proteolytic stability but also in antitumor activity. Among them, the glycosylated stapled peptide H-58 was identified as the most potential antitumor peptide. Flow cytometry and a competitive binding assay revealed that H-58 displayed significant antitumor selectivity. Confocal microscopy and nuclear staining with Hoechst dye demonstrated that H-58 entered the nucleus and caused DNA damage. In summary, the strategy of glycosylated stapled peptides is a promising approach for improving the antitumor selectivity, proteolytic stability, and antitumor activity of hymenochirin-1B, which can be used for other bioactive peptide modifications.
2. Host defense peptide Hymenochirin-1B induces lung cancer cell apoptosis and cell cycle arrest through the mitochondrial pathway
Yihan Zhang, Changning Sun, Guokai Xiao, Yuchao Gu Biochem Biophys Res Commun. 2019 Apr 30;512(2):269-275. doi: 10.1016/j.bbrc.2019.03.029. Epub 2019 Mar 15.
The antineoplastic activity of host defense peptide Hymenochirin-1B, has been extensively studied. However, the mechanism still remains unknown. In this study, linear peptide, Hymenochirin-1B, was synthesized via solid-phase peptide synthesis and evaluated for its anticancer efficacy. We found Hymenochirin-1B induced lung cancer cell apoptosis and cell cycle arrest at the G0/G1 phase. Moreover, Hymenochirin-1B could enter the cells and colocalized with mitochondria. Furthermore, decrease of mitochondrial membrane potential, increase of reactive oxygen species and the expression of apoptosis-associated protein (Bax/Bcl-2 ratio and activated Caspase-3) were observed in NCI-H1299 and A549 cells after Hymenochirin-1B treatment, suggesting that Hymenochirin-1B induced apoptosis via mitochondrial pathway. Our results provide new insights on the anticancer mechanism of Hymenochirin-1B, which may contribute to its further development into an antineoplastic drug in the future.
3. Stapling strategy enables improvement of antitumor activity and proteolytic stability of host-defense peptide hymenochirin-1B
Yulei Li, Minghao Wu, Qi Chang, Xia Zhao RSC Adv. 2018 Jun 19;8(39):22268-22275. doi: 10.1039/c8ra03446j. eCollection 2018 Jun 13.
Hymenochirin-1B is a cationic, amphipathic, α-helical host-defense peptide with 29 residues, which was isolated from skin secretions of the Congo clawed frog and showed potent cytotoxic activities against a range of tumor cell lines. However, the application of hymenochirin-1B as a drug is limited due to its conformational flexibility and poor proteolytic stability. In this research, a series of hydrocarbon-stapled analogs of hymenochirin-1B were designed, synthesized, and tested. Some analogs showed remarkable improvement not only in α-helicity, but also in antitumor activity and protease resistance when compared to the parent peptide. The results indicated that most stapled peptide analogues possessed improved activities against a series of tumor cells; in particular, the bicyclic stapled peptide H-10 showed promising prospects for novel anti-tumor drug development. Our data demonstrated the important impacts of the all-hydrocarbon crosslink stapling strategy on the biological activity, proteolytic stability and helicity of hymenochirin-1B.
