EPHA2 blockade reverses acquired resistance to afatinib induced by EPHA2-mediated MAPK pathway activation in gastric cancer cells and avatar mice.
Zuhua ChenZhentao LiuMengqi ZhangWenwen HuangZhongwu LiShubin WangCheng ZhangBin DongJing GaoLin ShenPublished in: International journal of cancer (2019)
Afatinib is a pan-HER inhibitor approved for specific types of lung cancer. We explored antitumor activity, predictive biomarkers and the potential mechanisms underlying antitumor effect and acquired resistance of afatinib in gastric cancer (GC) in vitro and in vivo. Five human GC cell lines and eight patient-derived xenograft (PDX) models with clear molecular profiling were used to evaluate the antitumor activity and mechanisms of afatinib. The ErbB family and downstream PI3K/AKT/mTOR and mitogen-activated protein kinase (MAPK) pathways were evaluated before and after afatinib treatment. An afatinib-resistant PDX model was established to explore both the potential mechanisms of drug resistance and reversal strategies. We found that afatinib exerted a strong tumor suppression in EGFR/HER2 highly amplified (copy number >6) or overexpressed (IHC 3+) PDX models and a moderate tumor suppression in EGFR/HER2 moderately expressed (IHC 2+) PDX models. Afatinib selectively inhibited the proliferation of HER2 highly amplified GC cells in a dose-dependent manner in vitro. Afatinib also exerted its antitumor effect by inducing cell apoptosis and cell arrest at G1 phase. Diminished activation of the ErbB family and downstream PI3K/AKT/mTOR and MAPK pathways was also observed. Erythropoietin-producing hepatocellular receptor A2 (EPHA2) upregulation and phosphorylation might be involved in afatinib-acquired resistance, and EPHA2 blockade could restore afatinib sensitivity. GC patients with amplification (copy number >6) or overexpression (IHC 3+) of EGFR/HER2 were most likely to benefit from afatinib treatment and EPHA2 blockade reversed acquired resistance to afatinib treatment, which could provide solid evidences for future clinical trials.
Keyphrases
- epidermal growth factor receptor
- advanced non small cell lung cancer
- tyrosine kinase
- copy number
- clinical trial
- mitochondrial dna
- small cell lung cancer
- cell proliferation
- endothelial cells
- mesenchymal stem cells
- randomized controlled trial
- single cell
- poor prognosis
- gene expression
- stem cells
- climate change
- transcription factor
- mass spectrometry
- endoplasmic reticulum stress
- adipose tissue
- smoking cessation
- current status
- double blind
- long non coding rna
- human health