Abstract
Recent studies have begun to highlight the diverse and tumor-specific microbiomes across multiple cancer types. We believe this work raises the important question of whether the classical "Hallmarks of Cancer" should be expanded to include tumor microbiomes. To answer this question, the causal relationships and co-evolution of these microbiotic tumor ecosystems must be better understood. Because host-microbe interactions should be studied in a physiologically relevant context, animal models have been preferred. Yet these models are often poor mimics of human tumors and are difficult to interrogate at high spatiotemporal resolution. We believe that in vitro tissue engineered platforms could provide a powerful alternative approach that combines the high-resolution of in vitro studies with a high degree of physiological relevance. This review will focus on tissue engineered approaches to study host-microbe interactions and to establish their role as an emerging hallmark of cancer with potential as a therapeutic target.