MUC1-Driven Guanylin Gene Delivery via Succinylated PEI-9 Nanocarriers for Colorectal Cancer Treatment: An In Silico and In Vitro Study

Purpose: Addressing colorectal cancer (CRC) poses a significant challenge, demanding the precise delivery of therapeutic agents to eliminate cancer cells while minimizing the impact on healthy cells. The strategic selection of therapeutic targets, the utilization of nanocarriers with optimal efficacy and low toxicity, and the development of gene constructs with targeted expression in cancer cells are crucial aspects of this pursuit. Methods: This study employed a systems biology approach to comprehensively investigate the guanylin hormone-encoding gene (GUCA2A). Exploration encompassed expression patterns across tissues and single-cell, clinical endpoints, methylation profiles, mutations, and immune and functional analyses. Subsequently, GUCA2A was identified as a potential target for gain-of-function studies, leading to its amplification and cloning into gene constructs featuring both a robust CMV promoter and a cancer-specific MUC1 promoter. The succinylated PEI-9, characterized by low toxicity and high gene transfer efficiency, was then fabricated and characterized on HCT-116 cancer cells and normal Vero cell lines. Results: Systems biology studies revealed guanylin’s aberrant expression patterns, methylation variations, and mutational changes as well as its remarkable association with immune engagement and poor survival outcomes in CRC. Moreover, SPEI-9 was introduced as a highly efficient and safe nanocarrier for gene delivery purposes. Additionally, In vitro, both guanylin-expressing constructs inhibited cell growth and proliferation, induced apoptosis, suppressed migration, and reduced colony formation. Notably, these effects were more robust but non-specific in cancer cells treated with constructs containing the CMV general promoter, while induction via the MUC1 promoter was more specific. Conclusion: A genetic construct featuring strong universal CMV and specific MUC1 promoter, expressing the guanylin peptide hormone, demonstrated highly effective and specific anticancer effects when transfected with nanocarriers characterized by high efficiency and low cytotoxicity. This nano-system holds promising implications for future targeted CRC therapy clinical trials.