Critical roles for EGFR and EGFR-HER2 clusters in EGF binding of SW620 human carcinoma cells.
J R Soc Interface
; 19(190): 20220088, 2022 05.
Article
in En
| MEDLINE
| ID: mdl-35612280
ABSTRACT
Epidermal growth factor (EGF) signalling regulates normal epithelial and other cell growth, with EGF receptor (EGFR) overexpression reported in many cancers. However, the role of EGFR clusters in cancer and their dependence on EGF binding is unclear. We present novel single-molecule total internal reflection fluorescence microscopy of (i) EGF and EGFR in living cancer cells, (ii) the action of anti-cancer drugs that separately target EGFR and human EGFR2 (HER2) on these cells and (iii) EGFR-HER2 interactions. We selected human epithelial SW620 carcinoma cells for their low level of native EGFR expression, for stable transfection with fluorescent protein labelled EGFR, and imaged these using single-molecule localization microscopy to quantify receptor architectures and dynamics upon EGF binding. Prior to EGF binding, we observe pre-formed EGFR clusters. Unexpectedly, clusters likely contain both EGFR and HER2, consistent with co-diffusion of EGFR and HER2 observed in a different model CHO-K1 cell line, whose stoichiometry increases following EGF binding. We observe a mean EGFR EGF stoichiometry of approximately 4 1 for plasma membrane-colocalized EGFR-EGF that we can explain using novel time-dependent kinetics modelling, indicating preferential ligand binding to monomers. Our results may inform future cancer drug developments.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Epidermal Growth Factor
/
ErbB Receptors
Type of study:
Prognostic_studies
Limits:
Humans
Language:
En
Journal:
J R Soc Interface
Year:
2022
Document type:
Article
Affiliation country: