Loss of an EGFR-amplified chromosome 7 as a novel mechanism of acquired resistance to EGFR-TKIs in EGFR-mutated NSCLC cells

e18091 Background: The epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) show notable effects for non-small cell lung cancers (NSCLC) harboring EGFR activating mutations. However, almost all patients eventually acquire resistance to EGFR-TKIs within several years. The major mechanisms of acquired resistance are acquisition of a secondary EGFR mutation T790M and amplification of MET. However, the mechanisms of other resistance remain unclear. In this study, we established novel erlotinib-resistant NSCLC cells and examined their resistant mechanism. Methods: Resistant cells were established by continuously exposing EGFR mutated NSCLC cells HCC827 to 0.1, 1 or 10 μM of erlotinib in 96 well plates for three months. The resistant mechanisms were determined by direct sequence analysis and EGFR FISH analysis. Results: Resistant cells were emerged from 14/96 and 3/96 wells by 0.1 μM and 1 μM of erlotinib exposure, respectively. No resistant cells appeared in the wells of 10 μM of erlotinib. The IC50 values of these resistant cells were more than 100-fold higher than that of parental cells. No secondary mutation of T790M was detected in any of the resistant cells. Instead, we found that 13/17 resistant cells were dominated by EGFR not amplified cells and one of resistant cells B10 consisted of more than 99.9% of them, while the parental cells consisted of 2.5% of EGFR not amplified cells. Then, we isolated EGFR not amplified clone 4D8 from parental cells and found that this clone also had a resistance to erlotinib comparable to the resistant cells B10. Metaphase FISH analysis showed that EGFR amplified cells in parental cells had a chromosome 7 containing multiple copies of EGFR, while EGFR not amplified cells in B10 did not have it. Furthermore, we found that EGFR not amplified cells were constantly emerged from EGFR amplified clone isolated from parental cells under normal cell culture condition. Conclusions: Loss of a chromosome 7 containing multiple copies of EGFR causes acquired resistance in HCC827 cells when exposed to relatively low concentration of erlotinib, while high concentration of erlotinib deprives HCC827 cells of the chance of emergence of resistant cells.

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Loss of Amplified Egfr Gene with Mutation as a Novel Mechanism of Acquired Resistance to Egfr-Tkis in Egfr Mutated Nsclc Cells

Annals of Oncology ◽

10.1016/s0923-7534(20)33781-9 ◽

2012 ◽

Vol 23 ◽

pp. ix390-ix391

Author(s):

K. Furugaki ◽

T. Iwai ◽

Y. Moriya ◽

K. Fujimoto-Ouchi

Keyword(s):

Acquired Resistance ◽

Egfr Gene ◽

Egfr Mutated ◽

Egfr Tkis

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Mechanism of Resistance to Epidermal Growth Factor Receptor-Tyrosine Kinase Inhibitors and a Potential Treatment Strategy

Cells ◽

10.3390/cells7110212 ◽

2018 ◽

Vol 7 (11) ◽

pp. 212 ◽

Cited By ~ 49

Author(s):

Tatsuya Nagano ◽

Motoko Tachihara ◽

Yoshihiro Nishimura

Keyword(s):

Lung Cancer ◽

Growth Factor ◽

Kinase Inhibitors ◽

Acquired Resistance ◽

Growth Factor Receptor ◽

T790m Mutation ◽

Epidermal Growth ◽

Egfr Mutated ◽

Egfr Tki ◽

Egfr Tkis

Treatment with epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) improves the overall survival of patients with EGFR-mutated non-small-cell lung cancer (NSCLC). First-generation EGFR-TKIs (e.g., gefitinib and erlotinib) or second-generation EGFR-TKIs (e.g., afatinib and dacomitinib) are effective for the treatment of EGFR-mutated NSCLC, especially in patients with EGFR exon 19 deletions or an exon 21 L858R mutation. However, almost all cases experience disease recurrence after 1 to 2 years due to acquired resistance. The EGFR T790M mutation in exon 20 is the most frequent alteration associated with the development of acquired resistance. Osimertinib—a third-generation EGFR-TKI—targets the T790M mutation and has demonstrated high efficacy against EGFR-mutated lung cancer. However, the development of acquired resistance to third-generation EGFR-TKI, involving the cysteine residue at codon 797 mutation, has been observed. Other mechanisms of acquired resistance include the activation of alternative pathways or downstream targets and histological transformation (i.e., epithelial–mesenchymal transition or conversion to small-cell lung cancer). Furthermore, the development of primary resistance through overexpression of the hepatocyte growth factor and suppression of Bcl-2-like protein 11 expression may lead to problems. In this report, we review these mechanisms and discuss therapeutic strategies to overcome resistance to EGFR-TKIs.

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SHP2 Inhibition Benefits Epidermal Growth Factor Receptor mutated Non-Small Cell Lung Cancer Therapy

Mini-Reviews in Medicinal Chemistry ◽

10.2174/1389557520666201127104104 ◽

2020 ◽

Vol 20 ◽

Author(s):

Leiming Xia ◽

Lu Wen ◽

Siying Wang

Keyword(s):

Stem Cells ◽

Synergistic Effects ◽

Growth Factor Receptor ◽

Egfr Mutations ◽

Combination Strategies ◽

Lung Cancer Therapy ◽

Src Homology ◽

Nsclc Patients ◽

Egfr Mutated ◽

Egfr Tkis

: EGFR-TKIs are facing a big challenge of everlasting activated EGFR mutations which lack of effective binding sites, this barrier confers the dark sides that largely limited the outcome of NSCLC patients in clinic. Combination strategies show impressive anti-tumor efficacy comparing with EGFR-TKI mono-treatment, especially targeting both stem cells and non-stem cells. SHP2 (Src homology 2-containing phosphotyrosine phosphatase 2) plays an important role in regulating various malignant biology through hyper-activating intracellular pathways due to either over expression or catalytical mutation. Some pathways that SHP2 involved in were overlaps with EGFR downstream, and others were not subject to EGFR. Interestingly, SHP2 suppression was reported that can destroy the stemness of cancer. Therefore, we hypothesize SHP2 inhibitor might be an promising drug that could synergistically enhance or sensitize the anti-tumor efficacy of EGFR-TKIs in EGFR mutated NSCLC patients. Here, we summarized the mechanisms of SHP2 in regulating EGFR mutated NSCLC patients, attempted to reveal the potential synergistic effects of SHP2 inhibitor combined with EGFR-TKIs.

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439O Tracking spatiotemporal T790M heterogeneity in patients with EGFR-mutant advanced NSCLC after acquired resistance to EGFR TKIs

Annals of Oncology ◽

10.1016/s0923-7534(21)00597-4 ◽

2016 ◽

Vol 27 ◽

pp. ix140

Author(s):

Y.-C. Zhang ◽

C. Pi ◽

E.-E. Ke ◽

Z.-H. Chen ◽

J. Su ◽

...

Keyword(s):

Advanced Nsclc ◽

Acquired Resistance ◽

Egfr Mutant ◽

Egfr Tkis

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Acquired Resistance to Osimertinib Plus Savolitinib Is Mediated by MET-D1228 and MET-Y1230 Mutations in EGFR-Mutated MET-Amplified Lung Cancer

JTO Clinical and Research Reports ◽

10.1016/j.jtocrr.2020.100071 ◽

2020 ◽

Vol 1 (4) ◽

pp. 100071

Author(s):

Andrew J. Piper-Vallillo ◽

Brian T. Halbert ◽

Deepa Rangachari ◽

Susumu S. Kobayashi ◽

Daniel B. Costa

Keyword(s):

Lung Cancer ◽

Acquired Resistance ◽

Egfr Mutated

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High expression of hypoxia inducible factor 1α related with acquired resistant to EGFR tyrosine kinase inhibitors in NSCLC

Scientific Reports ◽

10.1038/s41598-020-79801-1 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Qian Jin ◽

Feihua Huang ◽

Xianrong Xu ◽

Haidong He ◽

Yingqing Zhang

Keyword(s):

First Generation ◽

Kinase Inhibitors ◽

Acquired Resistance ◽

Hypoxia Inducible Factor ◽

High Expression ◽

Normal Lung ◽

Nsclc Tissue ◽

T790m Mutation ◽

Level Group ◽

Egfr Tkis

AbstractThe acquired resistance of the first generation epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) is a main factor leading to poor prognosis of non-small cell lung cancer (NSCLC), so we researched whether the high expression of hypoxia-inducible factor-1α (HIF-1α) in EGFR-TKIs sensitive NSCLC tissue tends to induce the acquired resistance. We detected the HIF-1α in normal lung tissue, EGFR-TKIs sensitive NSCLC tissue, the first generation EGFR-TKIs acquired resistant NSCLC tissue and acquired EGFR T790M mutation NSCLC tissue with the method of immunohistochemistry. Then, we compared the expression of HIF-1α in these tissues, and evaluate the effect of HIF-1α expression to the occurrence of acquired resistance. The expression of HIF-1α was much higher in the EGFR-TKIs sensitive NSCLC tissue than that in normal lung tissue. HIF-1α level became higher after the occurrence acquired resistance. There was negative correlation between HIF-1α level before receiving treatment and the time of acquired resistance occurring as well as the acquired EGFR T790M mutation occurring. As the treatment going on, EGFR-TKIs sensitivity rate of low HIF-1α level group was much higher than that of high level group. The high expression of HIF-1α related with the acquired resistance of the first generation EGFR-TKIs, and HIF-1α can be a biomarker to predict the early occurrence of acquired resistance.

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Efficacy of the CDK4/6 Dual Inhibitor Abemaciclib in EGFR-Mutated NSCLC Cell Lines with Different Resistance Mechanisms to Osimertinib

Cancers ◽

10.3390/cancers13010006 ◽

2020 ◽

Vol 13 (1) ◽

pp. 6

Author(s):

Silvia La Monica ◽

Claudia Fumarola ◽

Daniele Cretella ◽

Mara Bonelli ◽

Roberta Minari ◽

...

Keyword(s):

Cell Lines ◽

Kinase Inhibitor ◽

Acquired Resistance ◽

Growth Factor Receptor ◽

Resistance Mechanisms ◽

Resistant Cell ◽

Nsclc Cell ◽

Dual Inhibitor ◽

Nsclc Patients ◽

Egfr Mutated

Abemaciclib is an inhibitor of cyclin-dependent kinases (CDK) 4 and 6 that inhibits the transition from the G1 to the S phase of the cell cycle by blocking downstream CDK4/6-mediated phosphorylation of Rb. The effects of abemaciclib alone or combined with the third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) osimertinib were examined in a panel of PC9 and HCC827 osimertinib-resistant non-small cell lung cancer (NSCLC) cell lines carrying EGFR-dependent or -independent mechanisms of intrinsic or acquired resistance. Differently from sensitive cells, all the resistant cell lines analyzed maintained p-Rb, which may be considered as a biomarker of osimertinib resistance and a potential target for therapeutic intervention. In these models, abemaciclib inhibited cell growth, spheroid formation, colony formation, and induced senescence, and its efficacy was not enhanced in the presence of osimertinib. Interestingly, in osimertinib sensitive PC9, PC9T790M, and H1975 cells the combination of abemaciclib with osimertinib significantly inhibited the onset of resistance in long-term experiments. Our findings provide a preclinical support for using abemaciclib to treat resistance in EGFR mutated NSCLC patients progressed to osimertinib either as single treatment or combined with osimertinib, and suggest the combination of osimertinib with abemaciclib as a potential approach to prevent or delay osimertinib resistance in first-line treatment.

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