ABSTRACT
Cellular invasion is a key part of development, immunity and disease. Using an in vivo model of Caenorhabditis elegans anchor cell invasion, we characterize the gene regulatory network that promotes cell invasion. The anchor cell is initially specified in a stochastic cell fate decision mediated by Notch signaling. Previous research has identified four conserved transcription factors, fos-1 (Fos), egl-43 (EVI1/MEL), hlh-2 (E/Daughterless) and nhr-67 (NR2E1/TLX), that mediate anchor cell specification and/or invasive behavior. Connections between these transcription factors and the underlying cell biology that they regulate are poorly understood. Here, using genome editing and RNA interference, we examine transcription factor interactions before and after anchor cell specification. Initially, these transcription factors function independently of one another to regulate LIN-12 (Notch) activity. Following anchor cell specification, egl-43, hlh-2 and nhr-67 function largely parallel to fos-1 in a type I coherent feed-forward loop with positive feedback to promote invasion. Together, these results demonstrate that the same transcription factors can function in cell fate specification and differentiated cell behavior, and that a gene regulatory network can be rapidly assembled to reinforce a post-mitotic, pro-invasive state.
Footnotes
Author contributions
Conceptualization: T.N.M., D.Q.M.; Methodology: T.N.M., D.Q.M.; Validation: T.N.M., D.Q.M.; Formal analysis: T.N.M., J.J.S., N.J.P., D.Q.M.; Investigation: T.N.M., J.J.S., N.J.P., D.Q.M.; Resources: T.N.M., J.J.S., N.J.P., S.T., W.Z., D.Q.M.; Data curation: T.N.M., J.J.S., D.Q.M.; Writing - original draft: T.N.M., D.Q.M.; Writing - review & editing: T.N.M., J.J.S., N.J.P., D.Q.M.; Visualization: T.N.M., J.J.S., N.J.P., D.Q.M.; Supervision: W.Z., D.Q.M.; Project administration: D.Q.M.; Funding acquisition: D.Q.M.
Funding
This work was funded by the National Institutes of Health (NIH) National Cancer Institute [5R00CA154870-05 to D.Q.M.] and National Institute of General Medical Sciences (NIGMS) [1R01GM121597-01 to D.Q.M.]. D.Q.M. is also a Damon Runyon-Rachleff Innovator supported (in part) by the Damon Runyon Cancer Research Foundation [DRR-47-17]. T.N.M.-K. is supported by the NIH Eunice Kennedy Shriver National Institute of Child Health and Human Development [F31HD100091-01]. J.J.S. is supported by NIGMS [3R01GM121597-02S1] and N.J.P. is supported by the American Cancer Society [132969-PF-18-226-01-CSM]. Deposited in PMC for release after 12 months.