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Background

The vaccine-mediated therapy is one interesting option to treat lung cancer. This research introduces a novel therapeutic vaccine based on nanoliposomes containing multi-epitopes of MAGE-A3, TGF-β2, and VEGF-A to enhance immune responses against lung cancer cells.

Materials and methods

A bioinformatics approach was used to select antigens and to design a peptide-based vaccine. Nanoliposomes containing the multi-epitope peptide were synthesized and characterized. In the next step, Balb/c mice were randomly distributed into 2 groups receiving the peptide vaccine with doses of 10 and 100 mg/ml. In week 4, we assessed the antibody titers and cytokine secretion. The vaccine’s effects on A549 lung cancer cells were evaluated using MTT and Annexin V/PI assays, while Real-time PCR measured the expression of the apoptosis-related genes, Bax and Bcl2. Additionally, the vaccine’s efficacy was tested in a Humanized PDX model.

Results

Based on several bioinformatics analyses, such as Gene analysis by UALCAN, the protein-protein interactions by Zs Revelen, and the tumor purity by TIMER, we found that MAGE-A3, TGF-β2, and VEGF-A were good targets for vaccine design. The synthesized nanoliposomes exhibited a size range of 65–190 nm (mean size 110 nm) and a zeta potential of + 30 mV, with approximately 98% peptide loading. It was demonstrated the IgG antibodies against the merged peptide in both doses, even up to 10,000 times serum dilution. Also, the increased level of cytokines including, interleukin 4, interleukin 6, interleukin 10, tumor necrosis factor, and interferon-gamma has been shown in vaccinated mice. Our results showed that A549 cell viability decreased and apoptotic cells increased at both doses and exposure times. The real-time PCR analysis indicated a decrease in Bcl2 gene expression and an increase of Bax gene expression in lung cancer cells treated with serum of vaccinated mice. Importantly, the cancer volume significantly decreased in the immunized PDX models, from approximately 500 mm³ to 50 mm³ after 5 weeks.

Conclusions

This study suggests that nanoliposomal vaccines containing multi-epitope peptides may represent a promising therapeutic approach for lung cancer, eliciting robust immune and anti-tumor responses.

Graphical Abstract