Comparison of Cytotoxic Activity in Leukemic Lineages Reveals Important Features of β‐Hairpin Antimicrobial Peptides

Abstract

Several reports described different modes of cell death triggered by antimicrobial peptides (AMPs) due to direct effects on membrane disruption, and more recently by apoptosis and necrosis-like patterns. Cytotoxic curves of four β-hairpin AMPs (gomesin, protegrin, tachyplesin, and polyphemusin) were obtained from several human leukemic lineages and normal monocytes and Two cell lines were then selected based on their cytotoxic sensitivity. One was sensitive to AMPs (K562) and the other resistant (KG-1) and their effect compared between these lineages. Thus, these lineages were chosen to further investigate biological features related with their cytotoxicities to AMPs. Stimulation with AMPs produced cell death, with activation of caspase-3, in K562 lineage. Increase on the fluidity of plasmatic membrane by reducing cholesterol potentiated cytotoxicity of AMPs in both lineages. Quantification of internal and external gomesin binding to the cellular membrane of both K562 and KG-1 cells showed that more peptide is accumulated inside of K562 cells. Additionally, evaluation of multi-drug resistant pumps activity showed that KG-1 has more activity than K562 lineage. A comparison of intrinsic gene patterns showed great differences between K562 and KG-1, but stimulation with gomesin promoted few changes in gene expression patterns. Differences in internalization process through the plasma membrane, multidrug resistance pumps activity, and gene expression pattern are important features to AMPs regulated cell death. J. Cell. Biochem. 118: 1764-1773, 2017. © 2016 Wiley Periodicals, Inc.

Comparative in vitro study on cytotoxicity of recombinant β‐hairpin peptides

“…Comparison of our results with those reported previously indicated that synthetic and modified at N‐ and C‐terminus AMPs demostrate a higher cytotoxic propensity. In particular, the IC 50 values determined by Rodrigues et al for the synthetic gomesin bearing the N‐terminal pyroglutamic acid and the amidated C‐terminus averaged out at 2.87 and 8.13 μ m against HeLa and SKBR‐3 cell lines, respectively.…”

“…IC 50 values for lactoferricin B in case of human neuroblastoma cell lines ranged from 15 to 60 μ m ; α‐defensins 1–3 at a concentration of 15 μ m decreased the metabolic activity of lung cancer cells by 2.5 times . Synthetic protegrin caused death of 50% of erythroleukemia cells at concentrations of 12 μ m . It is noteworthy that the synthetic protegrin was amidated at the C‐terminus of the polypeptide chain.…”

“…This lactoferricin of bovine origin causes human leukemia and carcinoma cell death via apoptosis but kills neuroblastoma cells via necrosis . Protegrin‐1, a β‐hairpin AMP isolated from porcine leukocytes, demonstrated strong anticancer activity against leukemia and hepatocellular carcinoma cell lines …”

The Biological and Biophysical Properties of the Spider Peptide Gomesin

“…The in-vitro anti-cancer activity of Gm has been demonstrated in a number of studies using a range of murine and human cancer cell lines [ 3 , 9 , 12 , 13 , 14 , 15 , 16 ], as well as cells from devil facial tumour disease (DFTD) [ 18 ]. Table 2 summarises the anti-cancer activity of Gm on the most commonly tested cell lines.…”

“…Like many other AMPs, Gm shows cytotoxic activity against a wide range of pathogens, including clinically-relevant Gram-positive and Gram-negative bacteria, fungi and yeast, as well as demonstrating anti-malarial [ 3 , 4 ], anti-cryptococcal [ 5 ], and anti- Leishmania activity [ 1 , 3 , 6 , 7 , 8 , 9 , 10 , 11 ]. Gm also has in-vivo anti-cancer activity in a mouse model of melanoma [ 12 ], and in-vitro activity against a number of other human cancers [ 3 , 9 , 12 , 13 , 14 , 15 , 16 , 17 ]. In addition, Gm shows cytotoxic and anti-proliferative activity against devil facial tumour disease [ 18 ], a “parasitic” form of cancer that threatens the extinction of the Tasmanian devil ( Sarcophilus harrisii ), a unique Australian animal.…”