Ex vivo assay for organ-specific cancer cell invasion

Metastasis is the leading cause of cancer-related mortality, yet experimental models often fail to recapitulate the tissue-specific microenvironments shaping metastatic dissemination. While in vivo systems provide physiological relevance, they remain challenging for mechanistic studies. Conversely, conventional in vitro assays lack the organ-specific extracellular matrix (ECM) that regulates invasive behavior. Accessible models that balance biological relevance with experimental feasibility are thus needed.

We developed an ex vivo invasion platform based on mild detergent decellularization of mouse organs followed by vibratome slicing. This approach generates optically transparent lung, liver, and intestine ECM scaffolds that preserve native matrix architecture, mechanical properties, and retain biochemical hallmarks of their tissues of origin. Organ-derived matrices were integrated into standard microfluidic channels and analyzed using conventional fluorescence microscopy to enable quantitative assessment of cancer cell invasion. Benchmarking with breast cancer cell lines of defined invasive capacity, we could demonstrate the robustness and biological relevance of the system. Non-invasive MCF7 cells failed to infiltrate any scaffold. In turn, highly invasive MDA-MB-231 cells successfully invaded permissive soils (lung/liver) but were unable to colonize the non-permissive soil (intestine). Our platform enabled quantitative assessment of invasion rates, and revealed organ-specific transcriptional programs associated with invasive adaptation by RNA-seq.

The ex vivo organ-derived ECM framework presented here provides a scalable, cost-effective, and experimentally accessible system to study ECM-driven determinants of metastatic invasion. Preserving tissue-specific matrix cues while reducing reliance on animal models, it enables interrogation of ECM-driven metastasis mechanisms and therapeutic evaluation.