Differential osteo-specific invasion of patient-derived cancer cells in a microfluidic co-culture model

Cancer cell invasion to the surrounding extracellular matrix contributes to distant metastasis. There are no predictive models that focus on the accuracy of secondary site-infiltrative pattern. The degree of cancer invasion is regulated by receptive pre-metastatic niche. Herein, we show the feasibility of real time three-dimensional (3D) tissue-specific invasion of cancer stem like-cells (CSCs) from two different primary tumors employing a microfluidic device. An osteo-specific matrix (Osteomatrix-Collagen I, Os-Col) allows 3D osteogenic culture proven by differentiation of human adipose derived mesenchymal cells (ADSCs) into an osteoblastic lineage. In vitro enriched CSC-like cells (EpCAM+/CD44+/CD24- phenotype) derived from primary culture of oral squamous carcinoma and breast adenocarcinoma were used to demonstrate the differential strategy adopted for tumor progression. Morphological and viability parameters of the CSCs were monitored to assess the robustness as a realistic platform for in vitro osteotropic assay. Spatio-temporal elevated invasion into the osteo-specific matrix was evident in Os-Col compared to conventional collagen gel. Drug screening on co-cultures of CSClike cells and osteoblasts exhibited drug resistance. Overall, this work demonstrates that the proposed microfluidic chip with bone-specific ECM can efficiently replicate in vitro biochemical conditions for distinguishing tissue-specific invasive phenotype and screening drug resistance. This may serve as a tool to systematically examine the contribution of the bone microenvironment on the progression of various primary cancers to predict its invasive form, advancing personalized therapies.