Investigating the response of paediatric leukaemia-propagating cells to BCL-2 inhibitors.

Relapse of paediatric acute lymphoblastic leukaemia (ALL) may occur due to persistence of resistant cells with leukaemia-propagating ability (LPC). In leukaemia, the balance of B-cell lymphoma-2 (BCL-2) family proteins is disrupted, promoting survival of malignant cells and possibly LPC. A direct comparison of BCL-2 inhibitors, navitoclax and venetoclax, was undertaken on LPC subpopulations from B-cell precursor (BCP) and T-cell ALL (T-ALL) cases in vitro and in vivo. Responses were compared to BCL-2 levels detected by microarray analyses and Western blotting. In vitro, both drugs were effective against most BCP-ALL LPC, except CD34- /CD19- cells. In contrast, only navitoclax was effective in T-ALL and CD34- /CD7- LPC were resistant to both drugs. In vivo, navitoclax was more effective than venetoclax, significantly improving survival of mice engrafted with BCP- and T-ALL samples. Venetoclax was not particularly effective against T-ALL cases in vivo. The proportions of CD34+ /CD19- , CD34- /CD19- BCP-ALL cells and CD34- /CD7- T-ALL cells increased significantly following in vivo treatment. Expression of pro-apoptotic BCL-2 genes was lower in these subpopulations, which may explain the lack of sensitivity. These data demonstrate that some LPC were resistant to BCL-2 inhibitors and sustained remission will require their use in combination with other therapeutics.

Drug Sensitivity Assays of Human Cancer Organoid Cultures.

Drug sensitivity testing utilizing preclinical disease models such as cancer cell lines is an important and widely used tool for drug development. Importantly, when combined with molecular data such as gene copy number variation or somatic coding mutations, associations between drug sensitivity and molecular data can be used to develop markers to guide patient therapies. The use of organoids as a preclinical cancer model has become possible following recent work demonstrating that organoid cultures can be derived from patient tumors with a high rate of success. A genetic analysis of colon cancer organoids found that these models encompassed the majority of the somatic variants present within the tumor from which it was derived, and capture much of the genetic diversity of colon cancer observed in patients. Importantly, the systematic sensitivity testing of organoid cultures to anticancer drugs identified clinical gene-drug interactions, suggestive of their potential as preclinical models for testing anticancer drug sensitivity. In this chapter, we describe how to perform medium/high-throughput drug sensitivity screens using 3D organoid cell cultures.

Erratum to: Drug Sensitivity Assays of Human Cancer Organoid Cultures.

The protocol Drug Sensitivity Assays of Human Cancer Organoid Cultures has now been made available open access under a CC BY 4.0 license.

Organoid cultures recapitulate esophageal adenocarcinoma heterogeneity providing a model for clonality studies and precision therapeutics.

Esophageal adenocarcinoma (EAC) incidence is increasing while 5-year survival rates remain less than 15%. A lack of experimental models has hampered progress. We have generated clinically annotated EAC organoid cultures that recapitulate the morphology, genomic, and transcriptomic landscape of the primary tumor including point mutations, copy number alterations, and mutational signatures. Karyotyping of organoid cultures has confirmed polyclonality reflecting the clonal architecture of the primary tumor. Furthermore, subclones underwent clonal selection associated with driver gene status. Medium throughput drug sensitivity testing demonstrates the potential of targeting receptor tyrosine kinases and downstream mediators. EAC organoid cultures provide a pre-clinical tool for studies of clonal evolution and precision therapeutics.