Anti-Prostate Cancer Mechanisms Of AAP-H Oligopeptide From Anthopleura Anjunae

Prostate Cancer(PCa)is one of the most common malignant tumors in the male genitourinary system and is the leading cause of cancer death in men.In recent years,the incidence and mortality of PCa has not only increased in Western countries,but also rapidly among Asian populations.The traditional methods of treating PCa mainly include hormone therapy,orchiectomy,radiotherapy and chemotherapy.Surgical resection,chemotherapy,and radiation are often accompanied by many side effects such as low survival rates,poor drug resistance,neurotoxicity,and adverse events in the blood system.Androgen deprivation therapy for luteinizing hormone releasing hormone(LHRH)analogues or orchiectomy is usually effective initially for organ-limited prostate cancer,but patients inevitably develop from androgen-dependent to anti-castration and hormone-refractory Phenotype.These patients currently mainly rely on cytotoxic drugs,including vinblastine,etoposide,paclitaxel,estramustine and mitoxantrone.However,the treatment of these drugs is limited,and their toxicity and serious adverse reactions are worrying.With the understanding of the pathophysiology of prostate cancer,molecular targeted therapy has gradually become a new therapeutic strategy.Recent studies have shown that bioactive peptides extracted from natural products generally have low toxicity and anticancer activity.Therefore,there is an urgent need to develop a highly toxic and effective anti-prostate cancer peptide from natural products and to elucidate its anticancer mechanism.In this study,RNA transcriptome sequencing method was used.After treatment with Anthopleura anjunae oligopeptide(AAP-H,YVPGP),the expression of 80 genes was significantly different.The GO annotation,statistics and KEGG enrichment analysis of these genes were found.Compared with the control group,there were significant differences in 18 signaling pathways,including MAPK,PI3K/AKT,mTOR and apoptosis.The anti-tumor mechanism of AAP-H in prostate cancer DU-145 cells was further studied in vitro and in vivo.The results indicated that AAP-H is non-toxic and has anti-tumor activity.Cell cycle analysis indicated that AAP-H can block DU-145 cells from S phase to G2 phase.Western Blot(WB)method detected the role of phosphatidylinositol3-kinase/protein kinase B/mammalian Rapamycin target protein(PI3K/AKT/mTOR)signaling pathway in APP-H anti-tumor mechanism from protein level.The results showed that AAP-H resulted in a dose-dependent decrease in p-AKT(Ser473),p-PI3K(p85)and p-mTOR(Ser2448)levels,whereas compared to untreated DU-145 cells,the t-AKT,t-PI3 K level remains unchanged.Inhibition of PI3K/AKT/mTOR signaling pathway in DU-145 cells by using the inhibitor LY294002(10 μM)or rapamycin(20 nM)showed that the AAP-H-induced phosphorylation of AKT and mTOR was effectively attenuated.At the same time,the addition of inhibitors further increased AAP-H-induced Cleaved-Caspase-3levels.In addition,the effect of AAP-H on tumor growth and the role of the PI3K/AKT/mTOR signaling pathway in nude mice models are the same.Immunohistochemical analysis showed that activated AKT,PI3 K and mTOR levels were reduced in DU-145 xenograft tumors.WB showed that AAP-H treatment resulted in a dose-dependent decrease in p-AKT(Ser473),p-PI3K(p85)and p-mTOR(Ser2448)levels,while t-AKT and t-PI3 K levels remained unchanged.Similarly,BcL-xL levels were reduced after AAP-H treatment,while Bax levels were elevated.AAP-H also increased the levels of the promoter proteins Caspase 8,9 and the caspase 3,7 protein.Thus,the anti-tumor mechanism of APP-H on DU-145 cells may be involved in the regulation of the PI3K/AKT/mTOR signaling pathway,ultimately promoting apoptosis through the mitochondrial and death receptor pathways.Thus,the hydrophobic oligopeptide(YVPGP)can be used as an adjuvant for preventing or treating prostate cancer.