Reconstructing the tumor architecture into organoids

Cancer remains a leading health burden worldwide. One of the challenges hindering cancer therapy development is the substantial discrepancies between the existing cancer models and the tumor microenvironment (TME) of human patients. Constructing tumor organoids represents an emerging approach to recapitulate the pathophysiological features of the TME in vitro. Over the past decade, various approaches have been demonstrated to engineer tumor organoids as in vitro cancer models, such as incorporating multiple cellular populations, reconstructing biophysical and chemical traits, and even recapitulating structural features. In this review, we focus on engineering approaches for building tumor organoids, including biomaterial-based, microfabrication-assisted, and synthetic biology-facilitated strategies. Furthermore, we summarize the applications of engineered tumor organoids in basic cancer research, cancer drug discovery, and personalized medicine. We also discuss the challenges and future opportunities in using tumor organoids for broader applications.