Ex vivo modelling of human colorectal cancer liver metastasis by normothermic machine perfusion.

BACKGROUND Colorectal cancer liver metastasis (CRLM) is associated with poor survival, primarily due to acquired therapy resistance. While novel therapies arise, translation is limited by the lack of tumor models accurately representing dynamic microenvironmental interplay. Here, we show that ex vivo normothermic machine perfusion (NMP) offers a novel preclinical framework to study the intratumoral dynamics of CRLM biology. METHODS Six resected metastatic human livers were preserved for two days and subjected to multi-omic profiling of serially sampled adjacent liver and metastatic tissue using single-cell RNA sequencing (scRNA-seq) and spatial transcriptomics (ST). Tissue integrity was assessed and cross-validated by immunofluorescence (IF), high-resolution respirometry (HRR) and flow-cytometry. RESULTS NMP was successfuly applied to metastatic livers with minimal surgical adaptations, preserving both intrinsic hepatic properties and tissue viability over an extended duration. Single-cell and spatial mapping confirmed preservation of CRLM phenotypic properties and demonstrated high clinical translatability by applicability of the intrinsic epithelial consensus molecular subtypes to metastasis. Spatially deconvoluted pathway activities reflected functional tissue-microenvironments. Transcriptomic profiles - including those of tumor-associated myeloid cells - were preserved during NMP. Finally, we demonstrate tumor-associated myeloid cell persistence as a driver of disease progression and poor survival in colorectal cancer. CONCLUSION Our findings represent the basis for future innovative applications adopting NMP in the context of CRLM, providing a new preclinical tumor model avenue.