Interleukin (IL) 24 is a pro-inflammatory and tumor suppressor cytokine capable of inducing selective apoptosis in various cancer cells. BR2, on the other hand, is an anti-microbial peptide with selective penetrability to the cancer cells. In this study, we aimed to produce and purify a fusion protein containing IL24 as the toxic moiety fused to BR2, as targeting moiety, and then to evaluate its cytotoxic activities. For this purpose, the coding sequence of IL24-BR2 fusion protein and IL24 were cloned into the pET28a vector and used to transform E. coli BL21 (DE3) cells. Following induction of expression, protein purification performed using Ni-NTA chromatography. SDS-PAGE and western blotting were performed to confirm the expression and purification. Finally, cytotoxic effects of the purified proteins were evaluated on MCF-7 and HUVEC cell lines. Analysis of crude lysate of induced recombinant E. coli BL21 (DE3) bacteria and also purified proteins showed a band of approximately 22 and 18 KDa on SDS-PAGE and western blotting for IL24-BR2 and IL24, respectively. Finally, statistical analysis showed significant cytotoxic effects of IL24-BR2 on MCF-7 cells at 10, 20, and 40 μ g/mL concentrations compared to IL24 alone, which showed no significant cytotoxic effects on cancer cells except in the highest concentration. In conclusion, production and purification of IL24-BR2 fusion protein with potential specific toxicity toward cancer cells was successfully achieved. However, further investigation of the cytotoxic effects of this fusion protein on other cell lines and in vivo cancer models must be performed.

Purpose: In the previous studies, we designed an anticancer immunotoxin containing the catalytic and translocation domains of diphtheria toxin fused to BR2, a buforin II-derived antimicrobial peptide as a cancer-specific cell penetrating peptide, in order to target various cancer cells. The aim of this study was to evaluate the in vitro cytotoxicity of DT386– BR2 against K-562 cells as the most famous cell line for leukemia. Materials and Methods: MTT and flow-cytometry assays were used for determining the cytotoxic effects and cell death mechanism of DT386– BR2, respectively, against K-562 cell line. The recombinant DT386 and synthetic BR2 were used as the negative control in cytotoxicity assay. Results: The results of this study showed a significant reduction in survival of K-562 cells caused by DT386– BR2 as compared with BR2 and DT386 fragments. On the contrary, the flow-cytometry results showed apoptosis induction by DT386– BR2 after 12 h in a dose-and time-dependent manner. Conclusion: DT386– BR2 fusion protein can be used for further preclinical studies for determining its pharmacokinetic/ pharmacodynamic profiles and evaluating its anticancer efficacy in suitable animal models.

The important question, does bromine atom free radical, Br ., undergo a chemical reaction with a substrate before it dimerizes to dibromine Br 2, is investigated through electrochemical oxidation of bromide ion Br -. Cyclic voltammetry and spectrophotometry were used as electro-oxidation and monitoring devices. Simulation of cyclic voltammogram was used to obtain information about the mechanism of electro-oxidation process as well as reaction with substrates. It is shown that the primary electro-oxidation product (PEOP) of Br -, Br . (bromine atom-free radical), reacts with chemicals like chloroform, glycine, cytosine, etc. It can also dimerize, for example in acetonitrile. Reactions of PEOP Br . with substrate chloroform, acetone, DNA components adenine, cytosine, thymine and amino acid glycine were studied and their kinetics are reported here.

Background: Breast cancer is one of the most common diseases among women worldwide. The triple negative subtype is the most aggressive, with low tumor-free survival and the worst clinical evolution, requiring the development of more effective and targeted therapies. The present study investigated the in vitro pharmacological effects of the association of BR2 peptide with 2-aminoethyl dihydrogen phosphate (2-AEH2P) on MDA-MB-231 and 4T1 triple-negative breast cancer cells. Methods: The physical-chemical analysis of the peptide was performed using the Heliquest software, the cell viability was assessed using the MTT colorimeter method and the predictive pharmacological effect was evaluated using the Synergy Finder software. Results: The results showed the BR2 tumor penetration peptide and the 2-AEH2P+BR2 association significantly increased cytotoxicity in the MDA MB-231 and 4T1 tumor lines, without compromising the viability of the normal fibroblastic cells. The results also showed that depending on the time and concentration, a synergistic effect was observed for the association with tumor cells, with a therapeutic window between 0. 8 and 50μ, m for MDA-MB-231 tumor cells in 48h. Conclusion: The results demonstrated in vivo antitumor and antiproliferative efficiency for MDA-MB-231 and 4T1 tumor cells with low toxicity for normal fibroblast cells, with MDA MB-231 cells being more sensitive to treatments.