FIGURE 2.
Examples of multi-organ interactions that cannot be modeled with single organoid systems. (a) Migration and metastasis of tumor cells from one organ or organoid site to another, demonstrated in vitro in a metastasis-on-a-chip device in which colorectal carcinoma metastasizes from the colon to the liver [64]. (b) Reliance of a prodrug therapy, such as the anticancer 5-fluorouracil (5-FU) prodrug tegafur, on liver metabolism to activate the drug to generate a positive effect by successfully targeting tumor cells. (c) Inflammatory molecules secreted from organs such as the liver and lung upon drug injury can cause detrimental inflammatory responses and cell injury in downstream tissues. Abbreviations: IL, interleukin; TNF, tumor necrosis factor.