Fatty Acid Modification of the Anticancer Peptide LVTX-9 to Enhance Its Cytotoxicity against Malignant Melanoma Cells.

Fengjiao Li,Saizhi Wu,Ninglin Chen,Xinxin Zhao,Youlin Zeng,Jingyu Zhu,Zhonghua Liu,Peng Zhang

doi:10.3390/toxins13120867

Abstract

Spider venom is a valuable resource for the development of novel anticancer drugs. In this study, we focused on novel linear amphipathic α-helical anticancer peptide LVTX-9, which was derived from the cDNA library of the venom gland of the spider Lycosa vittata. The cytotoxicity of LVTX-9 against murine melanoma cells in the range of 1.56–200 μM was tested and found to be significantly lower than those of most anticancer peptides reported. Its IC50 was determined to be 59.2 ± 19.8 μM in a serum or 76.3 ± 12.7 μM in serum-free medium. Fatty acid modification is a promising strategy for improving peptide performance. Therefore, to enhance the cytotoxic activity of LVTX-9, fatty acid modification of this peptide was performed, and five different carbon chain length lipopeptides named LVTX-9-C12-C20 were produced. Among them, the lipopeptide LVTX-9-C18 showed the highest cytotoxic activity in relation to B16-F10 cells, whether in a serum or serum-free medium. Most importantly, the cytotoxic activity of LVTX-9-C18 was improved by about 12.9 times in a serum medium or 19.3 times in a serum-free medium compared to that of LVTX-9. Subsequently, assays including scanning electron microscopy, trypan blue staining, lactate dehydrogenase leakage assay, and hemolytic activity could indicate that the potential direct cell membrane disruption is the main mechanism of LVTX-9-C18 to induce cancer cell death. Furthermore, the LVTX-9-C18 also showed strong cytotoxicity in relation to 3D B16-F10 spheroids, which indicates it might be a promising lead for developing anticancer drugs.

Highlights

Despite current scientific and technological progress as well as the continuous improvement of medical standards, cancer remains a major public health problem worldwide, and the mortality rate for cancer is increasing year to year [1]
B16-F10 cells were chosen to investigate the cytotoxic activity of LVTX-9 using a cell counting Kit-8 (CCK-8) assay
LVTX-9 has the characteristics of anticancer peptides, it demonstrated low cytotoxic activity in cancer cells

Summary

Introduction

Despite current scientific and technological progress as well as the continuous improvement of medical standards, cancer remains a major public health problem worldwide, and the mortality rate for cancer is increasing year to year [1]. It is important to exploit novel, safe, and efficient anticancer drugs. Anticancer peptides (ACPs) and their derivatives have a broad anticancer spectrum and strong and rapid anticancer effects, which means they can be considered good candidate precursor molecules for cancer therapy. Natural toxins from venomous animals such as snakes, spiders, bees, scorpions, and conus, are precious resources for developing novel anticancer drugs [2,3,4,5,6,7,8]. Lycosin-I, isolated from the spider Lycosa singoriensis, with a linear amphipathic alpha-helical conformation, can effectively suppress tumor growth in vitro and in vivo [9]

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Conclusion