A retro-inverso cell-penetrating peptide for siRNA delivery

Liu

et al. 2020

Preprint

Background: Most cancers favor glycolytic-based glucose metabolism. Hexokinase-2 (HK2), the first glycolytic rate-limiting enzyme, shows limited expression in normal adult tissues but is overexpressed in many tumor tissues, including ovarian cancer. HK2 has been shown to be correlated with the progression and chemoresistance of ovarian cancer and could be a therapeutic target. However, the systemic toxicity of HK2 inhibitors has limited their clinical use. Since follicle-stimulating hormone (FSH) receptor (FSHR) is overexpressed in ovarian cancer but not in nonovarian healthy tissues, we designed FSHR-mediated nanocarriers for HK2 shRNA delivery to increase tumor specificity and decrease toxicity. Results: HK2 shRNA was encapsulated in a polyethylene glycol-polyethylenimine copolymer modified with the FSH β 33-53 or retro-inverso FSH β 33-53 peptide. The nanoparticle complex with FSH peptides modification effectively depleted HK2 expression and facilitated a shift towards oxidative glucose metabolism, with evidence of increased oxygen consumption rates, decreased extracellular acidification rates, and decreased extracellular lactate and glucose consumption in A2780 ovarian cancer cells and cisplatin-resistant A2780CP counterpart cells. Consequently, cell proliferation, invasion and migration were significantly inhibited, and tumor growth was suppressed even in cisplatin-resistant ovarian cancer. No obvious systemic toxicity was observed in mice. Moreover, the nanoparticle complex modified with retro-inverso FSH peptides exhibited the strongest antitumor effects and effectively improved cisplatin sensitivity by regulating cisplatin transport proteins and increasing apoptosis through the mitochondrial pathway. Conclusions: These results established HK2 as an effective therapeutic target even for cisplatin-resistant ovarian cancer and suggested a promising targeted therapeutic approach.

Section: Preparation and Characterization Of Nanoparticle Complexessupporting

confidence: 64%

Enhanced Antitumor Effects of Follicle-Stimulating Hormone Receptor-Mediated Hexokinase-2 Depletion on Ovarian Cancer Mediated by A Shift in Glucose Metabolism

Liu

et al. 2020

Preprint

“…But CPP made up of natural L amino acids are susceptible to proteolysis. The retroinverso version CADY-K peptide has been tried which has been successful in protecting it from proteolysis as well as retaining the capacity for cell penetration and self-assembly in form of nanoparticle with siRNA (Obasse, Taylor, Fullwood, & Allsop, 2017;Vaissière et al, 2017). The retroinverso analog of 18 residue long peptide PYC98 not only has fivefold more inhibition of the activity of JNK1 toward c-Jun but it also inhibits JNK1 activity toward EGFR-derived peptide (Ngoei, Catimel, Milech, Watt, & Bogoyevitch, 2013).…”

Section: Attempts Of Mimetics Using Retroinverso and Modified Analogsmentioning

confidence: 99%

Peptide and protein mimetics by retro and retroinverso analogs

Rai

2019

Chem Biol Drug Des

Retroinverso analog of a natural polypeptide can sometimes mimic the structure and function of the natural peptide. The additional advantage of using retroinverso analog is that it is resistant to proteolysis. The retroinverso analogs have peptide sequence in reverse direction with respect to natural peptide and also have chirality of amino acid inverted from L to D. The D amino acids cannot be recognized by common proteases of the body; therefore, these peptides will not be degraded easily and have a longer‐lasting effect as vaccine and inhibitor drugs. There have been many contested propositions about the geometric relationship between a peptide and its retro, inverso, or retroinverso analog. A retroinverso analog sometimes fails to adopt the structure that can mimic the function of the natural peptide. In such cases, partial retroinverso analog and other modifications can help in achieving the desired structure and function. Here, we review the theory, major experimental attempts, prediction methods, and alternative strategies related to retroinverso peptidomimetics.

Artificial Cells, Nanomedicine, and Biotechnology

“…Among the diverse class of peptides, cell-penetrating peptides (CPPs) have been extensively utilized for delivery of therapeutics [13]. Different CPPs including TP10, MPG, CADY, PepFect 6 (PF6), PF14, TAT, R9, R9-hLF, RV peptides, LAH4, RICK were reported for siRNA delivery [14][15][16][17][18][19][20][21][22][23][24]. Among CPPs, RICK was reported to form self-assembled structure.…”

Section: Introductionmentioning

confidence: 99%

Cyclic peptide-based nanostructures as efficient siRNA carriers

Panigrahi

Singh

Mishra

et al. 2018

RNA interference shows a great strategy for biological studies; however, delivering of small interfering RNA (siRNA) remains challenging. Although several delivery vehicles, including cell-penetrating peptides, have been developed, their implementation is often restricted because of their endosomal entrapment. Herein, we report the formation of self-assembled nanostructures from rationally designed cyclic peptides and explore them for efficient delivery of functional biomacromolecules such as siRNA into mammalian cells. The newly obtained soft materials make stable complexes with siRNAs, thereby increasing their stability and deliver fluorescent labelled siRNA inside the cells as evident from confocal microscopy analysis. Flow cytometry analysis reveals that significant uptake of FAM-siRNA occurs in the presence of peptide nanostructures compared with siRNA alone. Peptide nanostructure-mediated delivery of very low concentration of siRNA causes significant knockdown of the target gene as observed at protein level by Western blot analysis, which is comparable to lipofectamine, commercially available transfection agent.