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Updated: Nov 26, 2025
Profiling Sensitivity to Targeted Therapies in EGFR-Mutant NSCLC Patient-Derived Organoids
Published on: November 22, 2021
Altered Regulation of HIF-1α in Naive- and Drug-Resistant EGFR-Mutant NSCLC: Implications for a Vascular Endothelial
Monique B Nilsson1, Jacqulyne Robichaux1, Matthew H Herynk1
1Department of Thoracic/Head and Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
Introduction:
The treatment of patients with EGFR-mutant NSCLC with vascular endothelial growth factor (VEGF) inhibitors in combination with EGFR inhibitors provides a greater benefit than EGFR inhibition alone, suggesting that EGFR mutation status may define a patient subgroup with greater benefit from VEGF blockade. The mechanisms driving this potentially enhanced VEGF dependence are unknown.
Methods:
We analyzed the effect of EGFR inhibition on VEGF and HIF-1α in NSCLC models in vitro and in vivo. We determined the efficacy of VEGF inhibition in xenografts and analyzed the impact of acquired EGFR inhibitor resistance on VEGF and HIF-1α.
Results:
NSCLC cells with EGFR-activating mutations exhibited altered regulation of VEGF compared with EGFR wild-type cells. In EGFR-mutant cells, EGFR, not hypoxia, was the dominant regulator of HIF-1α and VEGF. NSCLC tumor models bearing classical or exon 20 EGFR mutations were more sensitive to VEGF inhibition than EGFR wild-type tumors, and a combination of VEGF and EGFR inhibition delayed tumor progression. In models of acquired EGFR inhibitor resistance, whereas VEGF remained overexpressed, the hypoxia-independent expression of HIF-1α was delinked from EGFR signaling, and EGFR inhibition no longer diminished HIF-1α or VEGF expression.
Conclusions:
In EGFR-mutant NSCLC, EGFR signaling is the dominant regulator of HIF-1α and VEGF in a hypoxia-independent manner, hijacking an important cellular response regulating tumor aggressiveness. Cells with acquired EGFR inhibitor resistance retained elevated expression of HIF-1α and VEGF, and the pathways were no longer EGFR-regulated. This supports VEGF targeting in EGFR-mutant tumors in the EGFR inhibitor-naive and refractory settings.
Insights
EGFR-mutant non-small cell lung cancer (NSCLC) shows increased dependence on vascular endothelial growth factor (VEGF). Targeting VEGF alongside EGFR inhibitors benefits patients, even after resistance develops.
Area of Science:
- Oncology
- Molecular Biology
- Cancer Research
Background:
- Epidermal growth factor receptor (EGFR) inhibitors improve outcomes in EGFR-mutant non-small cell lung cancer (NSCLC).
- Combination therapy with vascular endothelial growth factor (VEGF) inhibitors and EGFR inhibitors shows greater benefit than EGFR inhibition alone in NSCLC.
- The mechanisms underlying enhanced VEGF dependence in EGFR-mutant NSCLC are not fully understood.
Purpose of the Study:
- To investigate the role of EGFR signaling in regulating VEGF and HIF-1α in NSCLC.
- To determine the efficacy of VEGF inhibition in EGFR-mutant NSCLC models.
- To analyze the impact of acquired resistance to EGFR inhibitors on VEGF and HIF-1α pathways.
Main Methods:
- Analysis of VEGF and HIF-1α expression in NSCLC models with and without EGFR mutations.
- In vitro and in vivo studies assessing EGFR inhibition effects.
- Evaluation of VEGF inhibition efficacy in xenograft models.
- Investigation of acquired EGFR inhibitor resistance mechanisms.
Main Results:
- EGFR-mutant NSCLC cells exhibit altered VEGF regulation, with EGFR as the dominant regulator of HIF-1α and VEGF, independent of hypoxia.
- EGFR-mutant tumors are more sensitive to VEGF inhibition than wild-type tumors.
- Combination therapy of VEGF and EGFR inhibitors delayed tumor progression.
- Acquired resistance to EGFR inhibitors led to sustained VEGF overexpression, but HIF-1α and VEGF expression became independent of EGFR signaling.
Conclusions:
- EGFR signaling is a key regulator of HIF-1α and VEGF in EGFR-mutant NSCLC, irrespective of hypoxia.
- Elevated HIF-1α and VEGF persist in acquired resistance settings but are no longer EGFR-dependent.
- VEGF targeting is a viable strategy for EGFR-mutant NSCLC in both treatment-naive and refractory cases.
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