Current treatments focused on eradicating metastatic tumors have proven unsuccessful due to cancer's ability to quickly undergo epithelial-to-mesenchymal transition (EMT) and metastasize to secondary sites. Using human triple negative breast cancer cells (BCCs) as a model system, this work establishes a platform for the study of aggressive cancer phenotypes by demonstrating the inhibition of human metastatic cancer cells with 3D cultured embryonic stem cells (ESCs) encapsulated in alginate microstrands (ESC-microstrands), which mimic the embryonic microenvironment and recapitulate pluripotent signaling. Coculture with ESC-microstrands significantly decreases triple negative BCC proliferation and survival and reverses abnormal cancer metabolism. In particular, coculture with ESC-microstrands markedly restricts the metastatic potential of highly aggressive cancer cells, demonstrated as decreased migration and invasion, and reversed EMT marker expression. This indicates that pluripotent signaling from 3D ESC-microstrands could restrict cancer metastasis through restriction and reversion of EMT. Furthermore, two soluble factors associated with dysregulated oncogenic signaling were identified which display altered relative mRNA expression following coculture with ESC-microstrands. Future application of this model to mechanistic studies will enable a better understanding of cancer metastasis and the discovery of therapeutic targets for metastatic diseases.
Keywords: 3D coculture; alginate; breast cancer restriction; embryonic stem cell (ESC); epithelial-to-mesenchymal transition (EMT); metastasis.