Characterizing Acquired Resistance to TKIs in EGFR Mutant Lung Adenocarcinoma Cell Lines

2013 ◽  
Vol 9 ◽  
Author(s):  
Jing Sun
Keyword(s):  
Epithelial To Mesenchymal Transition ◽  
Kinase Inhibitors ◽  
Acquired Resistance ◽  
Growth Factor Receptor ◽  
Resistance Mechanisms ◽  
Resistant Cell ◽  
Egfr Mutations ◽  
Mesenchymal Transition ◽  
Major Mechanism ◽  
Egfr Mutant

Traditional treatments for non-small cell lung adenocarcinomas do produce impressive improvements in patient health. Newly developed biologically based treatments exploit the drug-sensitivity conferred by mutations in the epidermal growth factor receptor (EGFR). In adenocarcinomas, cell proliferation and survival depend on mutant EGFR activity. For patients with certain EGFR mutations, treatment with tyrosine kinase inhibitors (TKIs) rather than chemotherapy improves patient survival. However, almost every patient acquires resistance to TKI treatment. About 50% of acquired resistance is because of a secondary mutation in EGFR. MET gene amplification, which allows cells to use MET to activate downstream signals, is another established mechanism. A third known mechanism is epithelial to mesenchymal transition (EMT). About 30% of all resistance mechanisms still remain unknown. This semester, the HCC2279 EGFR-mutant human adenocarcinoma line was characterized in hopes of discovering new models of resistance. Growth inhibition assays and immunoblotting were used to analyze the effects of treatments and to examine the status of signaling molecules. The HCC2279 resistant line appeared to have an EGFR-independent mechanism and did not seem to use MET as a major mechanism of resistance. The resistant cells continued to grow in the presence of TKI and TKI plus MET inhibitor, and immunoblotting showed that TKIs were capable of completely inhibiting the activation and phosphorylation of EGFR and MET. Signs of EMT were detected via immunoblotting due to a loss of E-cadherin and gain of vimentin, and EMT was corroborated by histological changes such as a loss in resistant cell polarity.

scholarly journals Efficacy and acquired resistance for EGFR-TKI plus thoracic SBRT in patients with advanced EGFR-mutant non–small-cell lung cancer: a propensity-matched retrospective study

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xia Wang ◽  
Zhimin Zeng ◽  
Jing Cai ◽  
Peng Xu ◽  
Pingan Liang ◽  
...  
Keyword(s):  
Retrospective Study ◽  
Kinase Inhibitors ◽  
Acquired Resistance ◽  
Growth Factor Receptor ◽  
Progression Free Survival ◽  
Resistance Mechanisms ◽  
Egfr Mutations ◽  
Control Group ◽  
Real World Data ◽  
Baseline Characteristics

Abstract Background This retrospective study aimed to evaluate the efficacy of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) with stereotactic body radiation therapy (SBRT) and to elucidate potential mechanisms of acquired resistance. Methods Patients with advanced NSCLC harboring positive EGFR mutations after initial TKI therapy for at least 8 weeks were eligible for SBRT between August 2016 and August 2019. Eligible patients were treated with thoracic SBRT, and TKI was continued after SBRT until it was considered ineffective. The control group was treated with TKIs monotherapy. Propensity score matching (PSM, ratio of 1:2) was used to account for differences in baseline characteristics. Overall survival (OS), progression-free survival (PFS), treatment safety and resistance mechanisms were evaluated. Results Three hundred eight patients were included in the study population. Among them, 262 patients received TKIs alone, and 46 patients received TKIs with SBRT. Baseline characteristics were not significantly different between the two cohorts after PSM. The median PFS was 19.4 months in the TKIs +SBRT group compared to 13.7 months in the TKIs group (p = 0.034). An influence on OS has not yet been shown (p = 0.557). Of the 135 patients evaluated after PSM, 28 and 71 patients in the TKIs and TKIs +SBRT cohorts, respectively, had plasma cell-free DNA (cfDNA) next-generation sequencing (NGS) performed at baseline and disease progression. In the TKIs +SBRT cohort, the NGS results showed that T790M mutations were detected in 64.3% (18/28) of patients. Patients in the TKIs cohort exhibited fewer T790M-positive mutations (40.8%, p = 0.035) compared to patients in the TKIs +SBRT cohort. Conclusion Real world data prove that TKIs plus thoracic SBRT significantly extend PFS with tolerable toxicity. The mutation ratio of T790M was increased in the TKIs +SBRT group compared to the TKIs only group. Further randomized studies are warranted.

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

Cancers ◽  
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.

scholarly journals Understanding the Mechanisms of Resistance in EGFR-Positive NSCLC: From Tissue to Liquid Biopsy to Guide Treatment Strategy

2019 ◽  
Vol 20 (16) ◽  
pp. 3951 ◽  
Author(s):  
Marzia Del Re ◽  
Stefania Crucitta ◽  
Giulia Gianfilippo ◽  
Antonio Passaro ◽  
Iacopo Petrini ◽  
...  
Keyword(s):  
Treatment Strategy ◽  
Liquid Biopsy ◽  
Kinase Inhibitors ◽  
Growth Factor Receptor ◽  
Gene Mutations ◽  
Phosphatidyl Inositol ◽  
Egfr Mutations ◽  
Mechanisms Of Resistance ◽  
Alternative Source ◽  
Egfr Mutant

Liquid biopsy has emerged as an alternative source of nucleic acids for the management of Epidermal Growth Factor Receptor (EGFR)-mutant non-Small Cell Lung Cancer (NSCLC). The use of circulating cell-free DNA (cfDNA) has been recently introduced in clinical practice, resulting in the improvement of the identification of druggable EGFR mutations for the diagnosis and monitoring of response to targeted therapy. EGFR-dependent (T790M and C797S mutations) and independent (Mesenchymal Epithelial Transition [MET] gene amplification, Kirsten Rat Sarcoma [KRAS], Phosphatidyl-Inositol 4,5-bisphosphate 3-Kinase Catalytic subunit Alpha isoform [PI3KCA], and RAF murine sarcoma viral oncogene homolog B1 [BRAF] gene mutations) mechanisms of resistance to EGFR tyrosine kinase inhibitors (TKIs) have been evaluated in plasma samples from NSCLC patients using highly sensitive methods (i.e., digital droplet PCR, Next Generation Sequencing), allowing for the switch to other therapies. Therefore, liquid biopsy is a non-invasive method able to detect the molecular dynamic changes that occur under the pressure of treatment, and to capture tumor heterogeneity more efficiently than is allowed by tissue biopsy. This review addresses how liquid biopsy may be used to guide the choice of treatment strategy in EGFR-mutant NSCLC.

scholarly journals Triple Trouble: A Case of Multiple Resistance Mechanisms after First Generation EGFR-TKI in NSCLC

2019 ◽  
Vol 12 (2) ◽  
pp. 625-630 ◽  
Author(s):  
Mike Ralki ◽  
Brigitte Maes ◽  
Karin Pat ◽  
Jokke Wynants ◽  
Kristof Cuppens
Keyword(s):  
Kinase Inhibitor ◽  
Acquired Resistance ◽  
Growth Factor Receptor ◽  
Standard Of Care ◽  
Resistance Mechanisms ◽  
First Line ◽  
T790m Mutation ◽  
Her2 Mutation ◽  
Egfr Mutant ◽  
Egfr Tki

Epidermal growth factor receptor (EGFR)-targeted therapy has become standard of care in advanced stages EGFR-mutant non-small cell lung cancer. Acquired resistance to first-line EGFR-tyrosine kinase inhibitor (TKI) and subsequent disease progression is a common problem and mostly due to a secondary mutation (T790M) in EGFR. We report a case of a patient with EGFR-mutated lung adenocarcinoma who developed a complex resistance profile: T790M mutation, HER2 mutation and HER2 amplification after first-line EGFR-TKI. This patient was safely treated with a combination of osimertinib and trastuzumab and achieved a clinically meaningful and clear molecular response.This is the first reported case of acquired resistance to first-line EGFR-TKI based on three resistance mechanisms, treated with molecular targeted combination therapy.

Surrogate Predictive Biomarkers for Response to Anti-EGFR Agents: State of the Art and Challenges

2007 ◽  
Vol 22 (1_suppl4) ◽  
pp. 10-23 ◽  
Author(s):  
F. Cappuzzo ◽  
L. Toschi ◽  
G. Finocchiaro ◽  
C. Ligorio ◽  
A. Santoro
Keyword(s):  
Kinase Inhibitors ◽  
Acquired Resistance ◽  
Growth Factor Receptor ◽  
Predictive Biomarkers ◽  
Smoking History ◽  
Egfr Mutations ◽  
Gene Gain ◽  
Biological Variables ◽  
Drug Receptor ◽  
Exon 20

The epidermal growth factor receptor (EGFR) plays a key role in cancer development and progression in several human malignancies including non-small cell lung cancer (NSCLC). Several strategies aimed at inhibiting the EGFR have been investigated in the last years, including the use of small tyrosine kinase inhibitors (TKIs) directed against the intracellular domain of the receptor and monoclonal antibodies targeting its extracellular portion. Subgroups of patients who are more likely to respond to TKIs have been identified based on both clincal and biological features. Never-smoking history has emerged as the most relevant clinical characteristic predictive of response to TKIs in NSCLC, while presence of drug-sensitive EGFR mutations and EGFR gene gain represent critical biological variables associated with an improved outcome for patients exposed to these agents. Recent studies have highlighted the existence of biological factors involved in intrinsic and acquired resistance to TKIs, including k-ras, HER-2 and EGFR exon 20 mutations. Increasing knowledge of EGFR biology and drug-receptor interactions will allow to identify individuals who are likely to derive a clinical benefit from the proposed targeted therapy, sparing refractory patients expensive and potentially toxic treatment.

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