Figure 7.

Our proposed EGFR expression regulation and spatial dynamics in low risk (NIFTP) and malignant (PTC) thyroid neoplasms. In NIFTP, EGFR transcripts are abundant in association with reduced level of miR-7-5p. EGFR protein at the plasma membrane binds to its ligand, activates the ERK pathway to stimulate proliferation. The activated receptor is then internalized into the endosomal network where it is destined for degradation. Active p38 favors internalization and represses recycling of EGFR to the plasma membrane. In PTC, EGFR transcript level is low in association with high level of miR-146b-5p and high stress levels. The stress activated EGFR gets internalized, evades lysosomal degradation and accumulates in endosomes/exosomes. The ERK pathway is not active. Inhibition of p38 possibly by miR-146b-5p supports recycling of EGFR to the plasma membrane. Created using BioRender.com.