Design and in vivo evaluation of a multi-epitope vaccine that suppresses tumour growth in a murine colorectal cancer model

Harnessing the immune system through cancer vaccines offers a promising strategy to overcome tumour heterogeneity, which remains one of the most significant challenges in achieving effective treatment for colorectal cancer (CRC). In this study, we designed and validated a novel multi-epitope vaccine against CRC using integrated computational and experimental approaches. The final construct was developed through <i>in silico</i> prediction and optimisation, followed by recombinant expression and <i>in vivo</i> testing in a CRC mouse model. Mice receiving the multi-dose vaccine exhibited a mean tumour volume approximately 80% lower than that of the untreated cancer group. Additionally, IL-4 levels were significantly elevated (<i>p</i> < 0.0001), consistent with activation of humoral immune responses. Histopathological assessment showed largely preserved tissue architecture in the spleen, kidney, and liver. The multi-dose vaccine group achieved 100% survival, compared with 60% survival in the untreated cancer group. These results suggest the vaccine can suppress tumour progression, enhance immune responses, and provide systemic protection, supporting further preclinical development.