bioRxiv · 10.1101/2020.11.12.368522
Extracellular signal-regulated kinase mediates chromatin rewiring and lineage transformation in lung cancer
Abstract
SummaryLineage transformation between lung cancer subtypes is a poorly understood phenomenon associated with resistance to treatment and poor patient outcomes. Here, we aimed to model this transition to define underlying biological mechanisms and identify potential avenues for therapeutic intervention. Small cell lung cancer (SCLC) is neuroendocrine in origin and, in contrast to non-SCLC (NSCLC), rarely contains mutations that drive the MAPK pathway. Likewise, NSCLCs that transform to SCLC concomitantly with development of therapy resistance downregulate MAPK signaling, suggesting an inverse relationship between pathway activation and lineage state. To test this, we activated MAPK in SCLC through conditional expression of mutant KRAS or EGFR, which revealed suppression of the neuroendocrine differentiation program via ERK. We found that ERK induces the expression of ETS factors that mediate transformation into a NSCLC-like state. ATAC-seq demonstrated ERK-driven changes in chromatin accessibility at putative regulatory regions and global chromatin rewiring at neuroendocrine and ETS transcriptional targets. Further, ERK-mediated induction of ETS factors as well as suppression of neuroendocrine differentiation were dependent on histone acetyltransferase activities of CBP/p300. Overall, we describe how the ERK-CBP/p300-ETS axis promotes a lineage shift between neuroendocrine and non-neuroendocrine lung cancer phenotypes and provide rationale for the disruption of this program during transformation-driven resistance to targeted therapy.
Source connections
Explore related subjects
Keep this discovery
Explore connections, maps & timelines
Inoue, Y., Nikolic, A., Farnsworth, D., Liu, A., Ladanyi, M., Somwar, R., Gallo, M., Lockwood, W.. 2020-11-13. Extracellular signal-regulated kinase mediates chromatin rewiring and lineage transformation in lung cancer. https://doi.org/10.1101/2020.11.12.368522
Cite the original work for its findings. Save a collection to share your selection of sources.