Multi-kinase compensation rescues EGFR knockout in a cell line model of head and neck squamous cell carcinoma.

Abstract

BACKGROUND:

Head and neck squamous cell carcinoma (HNSCC) is a debilitating disease with poor survival rates. While the epidermal growth factor receptor (EGFR)-targeting antibody Cetuximab is approved for treatment, responses are limited and the molecular mechanisms driving resistance remain incompletely understood.

METHODS:

To better understand how cells survive without EGFR activity, we developed an EGFR knockout derivative of the UM-SCC-92 cell line using CRISPR/Cas9 technology. We then characterized changes to the transcriptome with RNAseq and changes in response to kinase inhibitors with resazurin cell viability assays. Finally, we tested if inhibitors with activity in the EGFR knockout model also had synergistic activity in combination with EGFR inhibitors in either wild type UM-SCC-92 cells or a known Cetuximab-resistant model.

RESULTS:

Functional and molecular analysis showed that knockout cells had decreased cell proliferation, upregulation of FGFR1 expression, and an enhanced mesenchymal phenotype. In fact, expression of common EMT genes including VIM, SNAIL1, ZEB1 and TWIST1 were all upregulated in the EGFR knockout. Surprisingly, EGFR knockout cells were resistant to FGFR inhibitor monotherapies, but sensitive to combinations of FGFR and either XIAP or IGF-1R inhibitors. Accordingly, both wild type UM-SCC-92 and Cetuximab-resistant UM-SCC-104 cells with were sensitive to combined inhibition of EGFR, FGFR and either XIAP or IGF-1R.

CONCLUSIONS:

These data offer insights into EGFR inhibitor resistance and show that resistance to EGFR knockout likely occurs through a complex network of kinases. Future studies of cetuximab-resistant HNSCC tumors are warranted to determine if this EMT phenotype and/or multi-kinase resistance is observed in patients.

• Authors: Megan L Ludwig, Nicole L Michmerhuizen, Jiayu Wang, Andrew C Birkeland, Behirda K Majchrowski, Sai Nimmagadda, Jingyi Zhai, Apurva Bhangale, Aditi Kulkarni, Hui Jiang, Paul L Swiecicki, J Chad Brenner
• Journal: Archives of oral biology (Arch Oral Biol) Vol. 156 Pg. 105822 (Dec 2023) ISSN: 1879-1506 [Electronic] England
• PMID: 37844343 (Publication Type: Journal Article)
• Copyright: Copyright © 2023. Published by Elsevier Ltd.

Chemical References

• Cetuximab
• EGFR protein, human
• ErbB Receptors

Topics

• Humans
• Cell Line, Tumor
• Cetuximab (pharmacology)
• ErbB Receptors
• Head and Neck Neoplasms (drug therapy, genetics)
• Squamous Cell Carcinoma of Head and Neck (drug therapy, genetics)