Recent advances in organotypic tissue slice cultures for anticancer drug development

Abstract

Organotypic tissue slice culture is established from animal or patient tissues and cultivated in an in vitro ecosystem. This technique has made countless contributions to anticancer drug development due to the vast number of advantages, such as the preservation of the cell repertoire and immune components, identification of invasive ability of tumors, toxicity determination of compounds, quick assessment of therapeutic efficacy, and high predictive performance of drug responses. Importantly, it serves as a reliable tool to stratify therapeutic responders from nonresponders and select the optimal standard-of-care treatment regimens for personalized medicine, which is expected to become a potent platform and even the gold standard for anticancer drug screening of individualization in the near future.

Keywords: anticancer drug discovery; individualized treatment; organotypic tissue slice culture; precision oncology.

Figure 1

Milestones in discovery and development of organotypic tissue slice culture. Key milestones in the prototype of organotypic tissue slice culture and the establishment of three-dimentional tumor slice culture are shown in light green. In 2011, US FDA approved the first immune checkpoint blockade drug, ipilimumab, in the clinical setting. Key milestones in the evaluation of drug efficacy, chemotherapy efficacy, immune checkpoint blockade efficacy, and chimeric antigen receptor T cell therapy efficacy are shown in purple. Abbreviations: CT, chemotherapy; ICB, immune checkpoint blockade; CAR-T, chimeric antigen receptor T cell; 3D-TSC, three-dimentional tumor slice culture.

Figure 2

Flow diagram of the organotypic tissue slice culture system for anticancer drug discovery. The organotypic tissue slice culture platform can be used to assess the tumoricidal efficacy of anticancer drugs. A. In the left panel, animal or patient-derived organotypic tissues are cut into the same figurate slices for the antitumor activity assessment of cancer drugs. Tumor slices are employed to evaluate the tumoricidal efficacy of anticancer drugs whereas normal tissue slices are used to observe the invasive ability of tumors and the efficacy of drugs against tumor invasiveness. Drug treatment is immediately initiated after the generation of the organotypic tissue slice culture system. The cell viability of slices is assessed on the 2-7th day of cultivation. B. The 3D-tumor slice culture (3D-TSC) system preserves the architecture and cell repertoire of the original tumor. This platform maximizes the retention of inter-tumor and intratumor heterogeneity, cellular-stromal interactions, and the complexity of the original tumor. The blood vessels on the slices will collapse within a short period after the cessation of blood circulation. Abbreviations: 3D-TSC, three-dimentional tumor slice culture; ECM, extracellular matrix; MSC, Mesenchymal cell; CAF, cancer-associated fibroblast; NK cell, natural killer cell; CSC, cancer stem cell.

Figure 3

3D-tumor slice culture increases the number of live cells and maintains the immune components of their original tumors. This figure was modified from our previous publication and gained approval from the correspondence authorship. A. Observation of tumor growth in 3D-TSCs derived from primary tumors formed by B477-GFP cells injected into the mammary fat pad of nude mice. Scale bar: 1 mm. B. Time-lapse of cell viability in 3D-TSCs derived from B477-GFP mouse tumors. C. Immunofluorescence staining of immune biomarkers derived from genetically engineered Brca1Co/Co; MMTV-Cre mouse in immunocompetent hosts. Blue is nuclear counterstaining by hematoxylin, and brown staining is positive protein staining by DAB. CD3e/CD8a: T lymphocytes; CD11b, macrophages and microglia marker; CD45, T, NK, dendritic, and lymphokine-activated killer cells marker; Scale bar: 100 µm. D. Pearson correlation coefficient identifying the correlation of gene expression between Day 1 to Day 8 with Day 0 in T cells and B cells.