Is LukS-PV a novel experimental therapy for leukemia?

Cytotoxic and apoptotic effects of chemically synthesized silver nanoparticles loaded with recombinant Staphylococcus LukS-PV toxin

Chronic myeloid leukemia (CML) accounts for approximately 15% of leukemias. LukS-PV, a Panton-Valentine leucocidin (PVL) component, is secreted by Staphylococcus aureus. Silver nanoparticles have increasingly been used for different purposes, most notably for drug delivery and anticancer agents. In this work, the cytotoxicity effect of recombinant LukS-PV protein, chemically synthesized AgNPs, and recombinant LukS-PV protein-loaded silver nanoparticles was investigated on human Chronic myeloid leukemia K562 cells and human normal embryonic kidney HEK293 cells. Cell apoptosis was investigated by staining with Annexin V/propidium iodide. The recombinant LukS-PV protein-loaded silver nanoparticles exhibited dose-dependent cytotoxicity and induced apoptosis in the K562 cells but had little effect on normal HEK293 cells. After 24 h of exposure to recombinant LukS-PV protein-loaded silver nanoparticles (IC50 concentration), flow cytometry showed that 31.17% of K562 cells were apoptotic. These results indicate that recombinant LukS-PV protein-loaded silver nanoparticles maybe are a potential chemotherapeutic agent candidate against K562 cells. Hence, silver nanoparticles could be used as drug carriers for toxin release to cancer cells.

The anticancer effect of recombinant LukS-PV protein and silver nanoparticles loaded with this protein

LukS-PV is a component of Panton-Valentine leucocidin (PVL) and is secreted by Staphylococcus aureus. Silver nanoparticles exhibit considerable potential as anticancer agents and drug delivery systems. Drug delivery is a way to deliver medicinal combinations to achieve a beneficial therapeutic effect. In the current study, recombinant LukS-PV protein-loaded silver nanoparticles were prepared and their cytotoxicity effect was analyzed on human breast cancer cells and human normal embryonic kidneys cells by MTT assay. Apoptosis was investigated by staining with Annexin V/propidium iodide. The recombinant LukS-PV protein-loaded silver nanoparticles showed dose-dependent cytotoxicity and induced apoptosis in the MCF7 cells and had a lesser effect on HEK293 cells. After 24 h exposure to the recombinant LukS-PV protein-loaded silver nanoparticles (IC50), Annexin V-FITC/PI FCM revealed that 33.2% of MCF7 cells were apoptotic. In conclusion, recombinant LukS-PV protein-loaded silver nanoparticles probably cannot be a better alternative for the targeted healing approaches to cancer therapies. Hence, it is suggested that silver nanoparticles could be utilized as a delivery system for releasing toxins into cancer cells.

Host immune genetic variations influence the risk of developing acute myeloid leukaemia: results from the NuCLEAR consortium

The purpose of this study was to conduct a two-stage case control association study including 654 acute myeloid leukaemia (AML) patients and 3477 controls ascertained through the NuCLEAR consortium to evaluate the effect of 27 immune-related single nucleotide polymorphisms (SNPs) on AML risk. In a pooled analysis of cohort studies, we found that carriers of the IL13_rs1295686A/A genotype had an increased risk of AML (P_Corr = 0.0144) whereas carriers of the VEGFA_rs25648T allele had a decreased risk of developing the disease (P_Corr = 0.00086). In addition, we found an association of the IL8_rs2227307 SNP with a decreased risk of developing AML that remained marginally significant after multiple testing (P_Corr = 0.072). Functional experiments suggested that the effect of the IL13_rs1295686 SNP on AML risk might be explained by its role in regulating IL1Ra secretion that modulates AML blast proliferation. Likewise, the protective effect of the IL8_rs2227307 SNP might be mediated by TLR2-mediated immune responses that affect AML blast viability, proliferation and chemorresistance. Despite the potential interest of these results, additional functional studies are still warranted to unravel the mechanisms by which these variants modulate the risk of AML. These findings suggested that IL13, VEGFA and IL8 SNPs play a role in modulating AML risk.