Apoptosis-like death-inducing property of tachyplesin I in Escherichia coli

pDNA-tachyplesin treatment stimulates the immune system and increases the probability of apoptosis in MC4-L2 tumor cells

Breast cancer is the most common cancer among women worldwide, and marine creatures are the most abundant reservoir of anticancer medicines. Tachyplesin peptides have shown antibacterial capabilities, but their potential to inhibit cancer growth and trigger cancer cell death has not been investigated. A synthetic tachyplesin nucleotide sequence was generated and inserted into the pcDNA3.1( +) Mammalian Expression Vector. PCR analysis and enzyme digesting procedures were used to evaluate the vectors' accuracy. The transfection efficiency of MCF-7 and MCF10-A cells was 57% and 65%, respectively. The proliferation of MCF-7 cancer cells was markedly suppressed. Administration of plasmid DNA (pDNA) combined with tachyplesin to mice with tumors did not cause any discernible morbidity or mortality throughout treatment. The final body weight curves revealed a significant reduction in weight among mice treated with pDNA/tachyplesin and tachyplesin at a dose of 100 µg/ml (18.4 ± 0.24 gr, P < 0.05; 11.4 ± 0.24 gr P < 0.01) compared to the control group treated with PBS (22 ± 0.31 gr). Animals treated with pDNA/tachyplesin and tachyplesin exhibited a higher percentage of CD4 + Foxp3 + Tregs, CD8 + Foxp3 + Tregs, and CD4 + and CD8 + T cell populations expressing CTLA-4 in their lymph nodes and spleen compared to the PBS group. The groups that received pDNA/tachyplesin exhibited a substantial upregulation in the expression levels of caspase-3, caspase-8, BAX, PI3K, STAT3, and JAK genes. The results offer new possibilities for treating cancer by targeting malignancies using pDNA/tachyplesin and activating the mTOR and NFκB signaling pathways.

Urechistachykinin I induced ferroptosis by accumulating reactive oxygen species in Vibrio vulnificus

Antimicrobial peptides (AMPs), such as urechistachykinin I (LRQSQFVGSR-NH2), derived from urechis unicinctus, have demonstrated antimicrobial activities. It exhibits low cytotoxicity and selectivity between microbial and mammalian cells suggesting its potent antimicrobial ability. However, the underlying antimicrobial mechanisms remain unknown. Herein, we elucidated the antibacterial action against Vibrio vulnificus, focusing on the reactive oxygen species (ROS). ROS is crucial for antibiotic-mediated killing and oxidative stress. After treatment with urechistachykinin I, superoxide anions and hydroxyl radicals increase, and the overproduction of ROS leads to oxidative damage and destruction of the redox system. Oxidation of the defense system like glutathione or glutathione peroxidase 4 illustrates the dysfunction of cellular metabolism and induces lipid peroxidation attributed to depolarization and integrity brokerage. Cell death demonstrated these properties, and additional experiments, including iron accumulation, liperfluo, and DNA fragmentation, were promoted. The results demonstrated that urechistachykinin I-induced ferroptosis-like death in Vibrio vulnificus is dependent on ROS production. KEY POINTS: • Urechistachykinin I induce reactive oxygen species production • Urechistachykinin I cause oxidative damaged on the V. vulnificus • Urechistachykinin I ferroptosis-like death in V. vulnificus.

Tachyplesin I and its derivatives: A pharmaco-chemical perspective on their antimicrobial and antitumor potential

INTRODUCTION

Increasing evidence suggests that intratumor microbiota are an intrinsic component in the tumor microenvironment across multiple cancer types, and that there is a close relationship between microbiota and tumor progression. Therefore, how to address the interaction between bacteria and malignances has become a growing concern. Tachyplesin I (TPI), a peptide with dual antimicrobial and antitumor effects, holds great promise as a therapeutic alternative for the aforementioned diseases, with the advantage of broad-spectrum activities, quick killing efficacy, and a low tendency to induce resistance.

AREAS COVERED

This review comprehensively summarizes the pharmacological mechanisms of TPI with an emphasis on its antimicrobial and antitumor potential. Furthermore, it presents advances in TPI derivatives and gives a perspective on their future development. The article is based on literature searches using PubMed and SciFinder to retrieve the most up-to-date information of TPI.

EXPERT OPINION

Bacterial infections and cancer both pose a serious threat to health due to their symbiotic interactions and drug resistance. TPI is anticipated to be a novel agent to control pathogenic bacteria and various tumors through multiple mechanisms of action. Indeed, the continuous advancements in chemical modification and innovative applications of TPI give hope for future improvements in therapeutic efficacy.