A systematic review on the culture methods and applications of 3D tumoroids for cancer research and personalized medicine

Abstract

Cancer is a highly heterogeneous disease, and thus treatment responses vary greatly between patients. To improve therapy efficacy and outcome for cancer patients, more representative and patient-specific preclinical models are needed. Organoids and tumoroids are 3D cell culture models that typically retain the genetic and epigenetic characteristics, as well as the morphology, of their tissue of origin. Thus, they can be used to understand the underlying mechanisms of cancer initiation, progression, and metastasis in a more physiological setting. Additionally, co-culture methods of tumoroids and cancer-associated cells can help to understand the interplay between a tumor and its tumor microenvironment. In recent years, tumoroids have already helped to refine treatments and to identify new targets for cancer therapy. Advanced culturing systems such as chip-based fluidic devices and bioprinting methods in combination with tumoroids have been used for high-throughput applications for personalized medicine. Even though organoid and tumoroid models are complex in vitro systems, validation of results in vivo is still the common practice. Here, we describe how both animal- and human-derived tumoroids have helped to identify novel vulnerabilities for cancer treatment in recent years, and how they are currently used for precision medicine.

Keywords: 3D models; Bioprinting; Cancer; Co-culture; Fluidic devices; Organoids; Precision medicine; Preclinical models; Tumoroids.

Fig. 1

3D model systems in cancer research. Applications of both human- and animal-derived tumoroids in cancer research (top). Tumoroids can be used for either cancer modeling with a focus on the tumor microenvironment (TME), or as a tool for personalized medicine and drug discovery based on the mutational landscape of patients. Comparison of different 3D model systems, including organoids, co-culture models, microfluidic devices, and in vivo models, highlighting the advantages and disadvantages of each model (bottom). Created with BioRender.com

Fig. 2

Co-culture techniques for tumoroid models. (A) Overview of state-of-the-art co-culture techniques in cancer research. (B) ALI tumoroid models of different cancer types for TME studies on day 30. Phase contrast (top), H&E (middle), and immunofluorescent staining (bottom) of ALI PDTs for DAPI (purple) and VIM, CA9, S100 or CK7, respectively (green) [183]. (C) Schematic depicting the generation of a bioprinted tumoroid co-culture model including fibroblasts and endothelial cells (top) [184]. Immunofluorescent staining of sections of bioprinted tumoroids stained for CD31 (yellow), VIM (red) and KRT8/18 (green) (bottom) [185]. (D) Schematic (middle) and immunofluorescence stainings (left, right) of a vascularized BrCa tumoroid-on-a-chip model for studying the TME and drug sensibility of cancer cells [186]. B. Copyright Elsevier, C. Copyright Wiley-VCH GmbH, D. Copyright Royal Society of Chemistry. Reproduced with permission. Created with BioRender.com

Fig. 3

In vivo methods for tumoroid models. (A) Overview of in vivo applications of both human and murine tumoroids. (B) Light microscopy pictures of tumoroids with different phenotypes (Scale bar 200 μm) and H&E staining of corresponding tumors after re-inoculation of subcutaneous tumor-derived tumoroids (Scale bar 50 μm) [237]. (C) Pearson correlation coefficient plots of gene expression between prostate tumors and matched tumoroid lines [238]. (D) Dynamic changes of immune cell populations during early, middle, and late stages in a novel tumoroid-based liver metastasis model [239]. (E) Real-time treatment of patient-derived xenograft mice representing a pretreatment tumor with either patient-matched neoadjuvant therapy (includes the drugs doxorubicin hydrochloride (Adriamycin) and cyclophosphamide, followed by treatment with paclitaxel (Taxol) = AC-T) (left) or with drugs selected from a xenograft-derived tumoroid screen (right) [108]. B, C, E adapted from corresponding citations; Springer Nature (Creative Commons Attribution 4.0 International). D adapted from Wiley (Creative Commons Attribution 4.0 International). Created with BioRender.com