Antitumor Activity and Mechanism of Action of Hormonotoxin, an LHRH Analog Conjugated to Dermaseptin-B2, a Multifunctional Antimicrobial Peptide

Mickael Couty (1) , Marie Dusaud (1) , Micka Miro-Padovani (1) , Liuhui Zhan (1) , Patricia Zadigue (1) , Loussiné Zargarian (2) , Olivier Lequin (3) , Alexandre de La Taille (1) , Jean Delbe (1) , Yamina Hamma-Kourbali (1) , Mohamed Amiche (4, 5, 1)

1 IMRB - Institut Mondor de Recherche Biomédicale
2 LBPA - Laboratoire de biologie et pharmacologie appliquée
3 LBM UMR 7203 - Laboratoire des biomolécules
4 IBPS - Institut de Biologie Paris Seine
5 IBPS-BIOSIPE - Biosynthèse des Signaux Peptidiques [IBPS]

Prostate cancer is the most common cancer in men. For patients with advanced or metastatic prostate cancer, available treatments can slow down its progression but cannot cure it. The development of innovative drugs resulting from the exploration of biodiversity could open new therapeutic alternatives. Dermaseptin-B2, a natural multifunctional antimicrobial peptide isolated from Amazonian frog skin, has been reported to possess antitumor activity. To improve its pharmacological properties and to decrease its peripheral toxicity and lethality we developed a hormonotoxin molecule composed of dermaseptin-B2 combined with d-Lys6-LHRH to target the LHRH receptor. This hormonotoxin has a significant antiproliferative effect on the PC3 tumor cell line, with an IC50 value close to that of dermaseptin-B2. Its antitumor activity has been confirmed in vivo in a xenograft mouse model with PC3 tumors and appears to be better tolerated than dermaseptin-B2. Biophysical experiments showed that the addition of LHRH to dermaseptin-B2 did not alter its secondary structure or biological activity. The combination of different experimental approaches indicated that this hormonotoxin induces cell death by an apoptotic mechanism instead of necrosis, as observed for dermaseptin-B2. These results could explain the lower toxicity observed for this hormonotoxin compared to dermaseptin-B2 and may represent a promising targeting approach for cancer therapyY

Keywords: anticancer drug; antimicrobial peptide (AMP); dermaseptin; frog skin peptides; LHRH; prostate cancer; Phyllomedusa bicolor; therapeutic peptides; anticancer drug

Domains: Pharmacology; Cancer; Urology and Nephrology

Mickael Couty, Marie Dusaud, Micka Miro-Padovani, Liuhui Zhan, Patricia Zadigue, et al.. Antitumor Activity and Mechanism of Action of Hormonotoxin, an LHRH Analog Conjugated to Dermaseptin-B2, a Multifunctional Antimicrobial Peptide. International Journal of Molecular Sciences, 2021, 22 (21), pp.11303. ⟨10.3390/ijms222111303⟩. ⟨hal-03388092⟩