3D microengineered vascularized tumor spheroid for drug delivery and efficacy testing

Tumor angiogenesis is regarded as a promising target for limiting cancer progression because tumor-associated vasculature supplies blood and provides a path for metastasis. Thus, in vitro recapitulation of vascularized tumors is critical to understand the pathology of cancer and identify the mechanisms by which tumor cells proliferate, metastasize, and respond to drugs. In this study, we microengineered a vascularized tumor spheroid (VTS) model to reproduce the pathological features of solid tumors. We first generated tumor cell-EC hybrid spheroids with self-assembled intratumoral vessels, which enhanced the uniformity of the spheroids and peritumoral angiogenic capacity compared to spheroids comprised only with cancer cells. Notably, the hybrid spheroid also exhibited expression profiles associated with aggressive behavior. The blood vessels sprouting around the hybrid spheroids on the VTS chip were interconnected with intratumoral vessels and displayed the distinctive characteristics of leaky tumor vessels. With the VTS chip showing a progressive tumor phenotype, we validated the suppressive effects of axitinib on tumor growth and angiogenesis, which depended on exposure dose and time, highlighting the significance of tumor vascularization to predict the efficacy of anticancer drugs. Ultimately, we effectively induced both lymphangiogenesis and angiogenesis around the tumor spheroid by promoting interstitial flow. Thus, our VTS model is a valuable platform with which to investigate the interactions between tumor microenvironments and explore therapeutic strategies in cancer. Overall design: Comparative gene expression profiling analysis of RNA-seq data for tumor spheroids consisting of HepG2 cells and tumor-EC hybrid spheroids in a different ratio.