Abstract A61: A novel image-guided genomics approach to dissect the mechanisms of collective cancer cell invasion

Abstract

Abstract During tumor metastasis, cancer cells invade as a collective pack to navigate the tumor microenvironment. In experimental models, this collective pack is phenotypically heterogenous and contains leader cells which pioneer invasion into the microenvironment and follower cells that immediately attach to and follow the leaders. To dissect the molecular mechanisms underlying this phenotypic heterogeneity, we developed a technique termed spatiotemporal genomic and cellular analysis (SAGA), which uses image-guided genomics to precisely select living, rare cell populations that are maintained within a physiologically relevant environment for downstream genomic and molecular analyses. In this manner, we can select, isolate, and amplify any living cell based upon phenotypic criteria. Using 3-D H1299 lung cancer cell spheroids, we precisely selected as few as 10 leader cells using the SAGA technique and extracted them from the bulk of a multicellular cancer spheroid embedded within a 3-D matrix. These isolated cells were used to create the first leader and follower purified cell cultures. The purified leader cell cultures continually show dynamic invasive patterns over time, while follower cells alone have limited invasive capabilities. Reintroducing limited numbers of leader cells, or even leader cell conditioned media, into follower cell cultures promoted invasion and motility in the follower cells. Genomic analysis comparing leader versus follower cell lines show significant enrichment in cell adhesion and vascular endothelial growth factor (VEGF) signaling pathways in leader cells. This was confirmed by protein analysis showing that leader cells secrete significantly higher levels of VEGF compared to follower cells, and VEGF inhibition abolished leader-follower collective invasion. Overall, our data show that SAGA can precisely select living cells based upon dynamic behaviors for genomic analysis and can amplify rare cell populations for subsequent molecular, cellular, and proteomic analyses. Therefore, this image-guided method has the potential to impact the field of tumor heterogeneity by uncovering genomic signatures of rare yet dynamic subpopulations within a heterogeneous cancer population. Citation Format: Jessica Konen, Bhakti Dwivedi, Jeanne Kowalski, Adam Marcus. A novel image-guided genomics approach to dissect the mechanisms of collective cancer cell invasion. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Metastasis; 2015 Nov 30-Dec 3; Austin, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(7 Suppl):Abstract nr A61.