Targeting MCF-7 Cell Line by Listeriolysin O Pore Forming Toxin Fusion with AHNP Targeted Peptide

Area of Science:

• Biotechnology
• Molecular Biology
• Cancer Therapy

Background:

• Tumor-targeting peptides are crucial for delivering therapeutic agents to specific cancer sites.
• Recombinant listeriolysin O (LLO) was engineered with a genetically fused Anti-HER2/neu peptide (AHNP) at its C-terminus.
• The goal was to enhance the specificity of this pore-forming toxin for tumor cells.

Purpose of the Study:

• To create a novel recombinant listeriolysin O (LLO) fused with an Anti-HER2/neu peptide (AHNP).
• To evaluate the cytotoxicity and tumor-targeting specificity of the engineered AHNP-LLO fusion toxin.
• To determine the optimal site for peptide modification on the LLO toxin for cancer therapy.

Main Methods:

• Two forms of LLO (with and without AHNP) were subcloned into a bacterial expression plasmid using PCR-based methods.
• Recombinant proteins were expressed in BL21 DE3 cells and purified using Ni-NTA affinity chromatography.
• Cytotoxicity and specificity were assessed by treating MDA-MB-231 and MCF-7 cell lines with the toxins.

Main Results:

• The engineered AHNP-LLO toxin exhibited a 9-fold decrease in cytotoxicity compared to wild-type LLO.
• The specificity of the AHNP-LLO toxin was reduced, as indicated by altered IC50 values on different cell lines.
• IC50 values for LLO were 21 ng/ml (MDA-MB-231) and 5 ng/ml (MCF-7); for AHNP-LLO, they were 140 ng/ml and 60 ng/ml, respectively.

Conclusions:

• Modifying the C-terminal of listeriolysin O (LLO) with peptides like AHNP is not optimal for enhancing tumor-targeting specificity.
• The N-terminal region of LLO appears to be a more suitable site for engineering and attaching peptide modules for improved cancer therapy applications.
• Further research should explore N-terminal modifications for developing more effective tumor-specific LLO-based therapeutics.