The tyrosine kinase inhibitor Gefitinib reduces C. elegans stress-induced sleep, but not likely via LET-23/EGFR inhibition.

The anticancer drug Gefitinib is a tyrosine kinase inhibitor with selectivity for the Epidermal Growth Factor Receptor (EGFR/ErbB1). As the C. elegans EGF receptor LET-23 shares notable structural homology over its kinase domain with human EGFR, we wished to examine whether Gefitinib treatment can interfere with LET-23-dependent processes. We show that Gefitinib disrupts C. elegans stress-induced sleep (SIS) but does not impact EGF overexpression-induced sleep nor vulva induction. These findings indicate that Gefitinib does not interfere with LET-23 signaling and impairs SIS through an off-target mechanism.