Genetic heterogeneity within collective invasion packs drives leader and follower cell phenotypes

Abstract

Collective invasion, the coordinated movement of cohesive packs of cells, has become recognized as a major mode of metastasis for solid tumors. These packs are phenotypically heterogeneous and include specialized cells that lead the invasive pack and others that follow behind. To better understand how these unique cell types cooperate to facilitate collective invasion, we analyzed transcriptomic sequence variation between leader and follower populations isolated from the H1299 non-small cell lung cancer cell line using an image-guided selection technique. We now identify 14 expressed mutations that are selectively enriched in leader or follower cells, suggesting a novel link between genomic and phenotypic heterogeneity within a collectively invading tumor cell population. Functional characterization of two phenotype-specific candidate mutations showed that ARP3 enhances collective invasion by promoting the leader cell phenotype and that wild-type KDM5B suppresses chain-like cooperative behavior. These results demonstrate an important role for distinct genetic variants in establishing leader and follower phenotypes and highlight the necessity of maintaining a capacity for phenotypic plasticity during collective cancer invasion.

Epigenetically heterogeneous tumor cells direct collective invasion through filopodia-driven fibronectin micropatterning

“…We next performed RNA-seq on isolated leader and follower cells and the parental population to assess gene expression differences (13). Principal component analysis showed that parental, leader, and follower cells each had distinct gene expression patterns ( fig.…”

“…RNA-seq was performed in triplicate on H1299 parental, leader, and follower cells. RNA library preparation and sequencing were performed by the Emory Integrated Genomics Core and Omega BioTek Inc., as previously described (13). Data processing, read alignment, quality control, and statistical analyses were performed by the Emory Biostatistics and Bioinformatics Shared Resource, as previously described (13).…”

“…Competing interests: The authors declare no competing interests with this work. Data and materials availability: RNA-seq data have been deposited in the Sequence Read Archive (SRA) with the BioProject accession number PRJNA542374 ( 13 ). DNA methylation data have been deposited into the GEO archive with accession number GSE147153.…”

Prognostic significance of an invasive leader cell–derived mutation cluster on chromosome 16q

“…Because leader cells are crucial for collective invasion in 3‐dimensional assays, 11 we hypothesized that patients with NSCLC with genetic evidence of leader cells within the primary tumor could be at higher risk for disease progression and recurrence. Our previous data showed that H1299 leader and follower cells contain distinct mutational profiles 16 . Additional inclusion of known variants from the dbSNP database 23 resulted in 17 leader‐specific mutations and 18 follower‐specific mutations (Fig.…”

“…Furthermore, point mutations could affect protein function without affecting gene expression. For example, we previously showed that a leader‐specific mutation in ARP3, while not affecting messenger RNA expression in leader cells, conferred leader cell behavior when it was introduced into follower cells 16 …”