CRISPR screens in cancer spheroids identify 3D growth-specific vulnerabilities

• Published in: Nature (London) Vol. 580; no. 7801; pp. 136 - 141
• Main Authors: Han, Kyuho, Pierce, Sarah E., Li, Amy, Spees, Kaitlyn, Anderson, Gray R., Seoane, Jose A., Lo, Yuan-Hung, Dubreuil, Michael, Olivas, Micah, Kamber, Roarke A., Wainberg, Michael, Kostyrko, Kaja, Kelly, Marcus R., Yousefi, Maryam, Simpkins, Scott W., Yao, David, Lee, Keonil, Kuo, Calvin J., Jackson, Peter K., Sweet-Cordero, Alejandro, Kundaje, Anshul, Gentles, Andrew J., Curtis, Christina, Winslow, Monte M., Bassik, Michael C.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.04.2020; Nature Publishing Group
• Subjects: 13; 13/106; 45/41; 631/208; 631/67; Adenocarcinoma - genetics; Adenocarcinoma - metabolism; Adenocarcinoma - pathology; Amino Acid Motifs; Animals; Cancer; Carboxypeptidase D; Carboxypeptidases - antagonists & inhibitors; Carboxypeptidases - deficiency; Carboxypeptidases - genetics; Carboxypeptidases - metabolism; Cell Culture Techniques - methods; Cell Proliferation - genetics; CRISPR; CRISPR-Cas Systems - genetics; Diagnosis; DNA sequencing; Female; Genes; Genetic aspects; Genetic engineering; Genome, Human - genetics; Genomes; Genomics; Growth factors; Humanities and Social Sciences; Humans; Insulin; Insulin-like growth factors; Lung cancer; Lung diseases; Lung Neoplasms - genetics; Lung Neoplasms - metabolism; Lung Neoplasms - pathology; Methods; Mice; Molecular Targeted Therapy; multidisciplinary; Mutation; Nucleotide sequencing; Phenotype; Phenotypes; Receptor, IGF Type 1 - chemistry; Receptor, IGF Type 1 - metabolism; Receptors; Science; Science (multidisciplinary); Signal Transduction; Spheroids; Spheroids, Cellular - metabolism; Spheroids, Cellular - pathology; Three dimensional models; Tumors; Two dimensional models; Xenograft Model Antitumor Assays; United States
• ISSN: 0028-0836; 1476-4687; 1476-4687
• DOI: 10.1038/s41586-020-2099-x

Cancer genomics studies have identified thousands of putative cancer driver genes 1 . Development of high-throughput and accurate models to define the functions of these genes is a major challenge. Here we devised a scalable cancer-spheroid model and performed genome-wide CRISPR screens in 2D monolayers and 3D lung-cancer spheroids. CRISPR phenotypes in 3D more accurately recapitulated those of in vivo tumours, and genes with differential sensitivities between 2D and 3D conditions were highly enriched for genes that are mutated in lung cancers. These analyses also revealed drivers that are essential for cancer growth in 3D and in vivo, but not in 2D. Notably, we found that carboxypeptidase D is responsible for removal of a C-terminal RKRR motif 2 from the α-chain of the insulin-like growth factor 1 receptor that is critical for receptor activity. Carboxypeptidase D expression correlates with patient outcomes in patients with lung cancer, and loss of carboxypeptidase D reduced tumour growth. Our results reveal key differences between 2D and 3D cancer models, and establish a generalizable strategy for performing CRISPR screens in spheroids to reveal cancer vulnerabilities. CRISPR screens in a 3D spheroid cancer model system more accurately recapitulate cancer phenotypes than existing 2D models and were used to identify carboxypeptidase D, acting via the IGF1R, as a 3D-specific driver of cancer growth.