• Biomolecules & Therapeutics
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• v.30 no.1
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• pp.19-27
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• 2022

Epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase widely expressed in many cancers such as non-small cell lung cancer (NSCLC), pancreatic cancer, breast cancer, and head and neck cancer. Mutations such as L858R in exon 21, exon 19 truncation (Del19), exon 20 insertions, and others are responsible for aberrant activation of EGFR in NSCLC. First-generation EGFR tyrosine kinase inhibitors (TKIs) such as gefitinib and erlotinib have clinical benefits for EGFR-sensitive (L858R and Del19) NSCLC patients. However, after 10-12 months of treatment with these inhibitors, a secondary T790M mutation at the gatekeeper position in the kinase domain of EGFR was identified, which limited the clinical benefits. Second-generation EGFR irreversible inhibitors (afatinib and dacomitinib) were developed to overcome this T790M mutation. However, their lack of selectivity toward wild-type EGFR compromised their clinical benefits due to serious adverse events. Recently developed third-generation irreversible EGFR TKIs (osimertinib and lazertinib) are selective toward driving mutations and the T790M mutation, while sparing wild-type EGFR activity. The latest studies have concluded that their efficacy was also compromised by additional acquired mutations, including C797S, the key residue cysteine that forms covalent bonds with irreversible inhibitors. Because second- and third-generation EGFR TKIs are irreversible inhibitors, they are not effective against C797S containing EGFR triple mutations (Del19/T790M/C797S and L858R/T790M/C797S). Therefore, there is an urgent unmet medical need to develop next-generation EGFR TKIs that selectively inhibit EGFR triple mutations via a non-irreversible mechanism.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.18
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• pp.8191-8196
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• 2016

Inhibition of EGFR-EGF interactions forms an important therapeutic rationale in treatment of non-small cell lung carcinoma. Established inhibitors have been successful in reducing proliferative processes observed in NSCLC, however patients suffer serious side effects. Considering the narrow therapeutic window of present EGFR inhibitors, the present study centred on identifying high efficacy EGFR inhibitors through structure based virtual screening strategies. Established inhibitors - Afatinib, Dacomitinib, Erlotinib, Lapatinib, Rociletinib formed parent compounds to retrieve similar compounds by linear fingerprint based tanimoto search with a threshold of 90%. The compounds (parents and respective similars) were docked at the EGF binding cleft of EGFR. Patch dock supervised protein-protein interactions were established between EGF and ligand (query and similar) bound and free states of EGFR. Compounds ADS103317, AKOS024836912, AGN-PC-0MXVWT, GNF-Pf-3539, SCHEMBL15205939 were retrieved respectively similar to Afatinib, Dacomitinib, Erlotinib, Lapatinib, Rociletinib. Compound-AGN-PC-0MXVWT akin to Erlotinib showed highest affinity against EGFR amongst all the compounds (parent and similar) assessed in the study. Further, AGN-PC-0MXVWT brought about significant blocking of EGFR-EGF interactions in addition showed appreciable ADMET properties and pharmacophoric features. In the study, we report AGN-PC-0MXVWT to be an efficient and high efficacy inhibitor of EGFR-EGF interactions identified through computational approaches.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.8
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• pp.4485-4494
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• 2013

Epidermal growth factor receptor (EGFR) is considered to be one of the key driver genes in non-small cell lung cancer (NSCLC). Several clinical trials have shown great promise of EGFR tyrosine kinase inhibitors (TKIs) in the first-line treatment of NSCLC. Many advances have been made in the understanding of EGFR signal transduction network and the interaction between EGFR and tumor microenvironment in mediating cancer survival and development. The concomitant targeted therapy and radiation is a new strategy in the treatment of NSCLC. A number of preclinical studies have demonstrated synergistic anti-tumor activity in the combination of EGFR inhibitors and radiotherapy in vitro and in vivo. In the present review, we discuss the rationale of the combination of EGFR inhibitors and radiotherapy in the treatment of NSCLC.

• Tuberculosis and Respiratory Diseases
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• v.75 no.5
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• pp.188-198
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• 2013

Over the past decade, several kinase inhibitors have been approved based on their clinical benefit in cancer patients. Unfortunately, in many cases, patients develop resistance to these agents via secondary mutations and alternative mechanisms. To date, several major mechanisms of acquired resistance, such as secondary mutation of the epidermal growth factor receptor (EGFR) gene, amplification of the MET gene and overexpression of hepatocyte growth factor, have been reported. This review describes the recent findings on the mechanisms of primary and acquired resistance to EGFR tyrosine kinase inhibitors and acquired resistance to anaplastic lymphoma kinase inhibitors, primarily focusing on non-small cell lung carcinoma.

• Molecular & Cellular Toxicology
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• v.3 no.3
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• pp.159-164
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• 2007

Stimulation of epidermal growth factor receptor (EGFR) is essential in signaling pathway of tumor cells. Thus, EGFR has intensely studied as an anticancer target. We developed hologram quantitative structure activity relationship (HQSAR) models for data set which consists of tricyclic azepine derivatives showing inhibitory activities for EGFR. The optimal HQSAR model was generated with fragment size of 6 to 7 while differentiating fragments having different atom and connectivity. The model showed cross-validated $q^2$ value of 0.61 and non-cross-validated $r^2$ value of 0.93. When the model was validated with an external set excluding one outlier, it gave predictive $r^2$ value of 0.43. The contribution maps generated from this model were used to interpret the atomic contribution of each atom to the overall inhibition activity. This can be used to find more efficient EGFR inhibitors.

• Bulletin of the Korean Chemical Society
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• v.31 no.12
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• pp.3525-3529
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• 2010

Tyrosine kinase inhibitors (TKIs) are currently used in the treatment of patients with advanced lung cancer. Recent studies on non-small cell lung cancer have shown that some patients carry somatic mutations in the epidermal growth factor receptor (EGFR) gene. Such mutations correlate with the effectiveness of certain TKIs. To detect a small amount of mutant EGFR among an abundance of wild-type EGFR, we have developed a highly sensitive and simple method using PNA-mediated real-time PCR clamping. The PNA-mediated real-time PCR clamping enables detection of EGFR mutants down to approximately 1% mutant -to- wild type. The total assay time was short as it required only 2.0 hr. Thus, PNA-mediated real-time PCR clamping can easily be applied to clinical samples for identification of DNA carrying EGFR mutations and also appear to be the best assay to detect somatic mutations.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.2
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• pp.695-700
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• 2013

Background: Mutations affecting the epidermal growth factor receptor (EGFR) are good predictors of clinical efficacy of EGFR tyrosine kinase inhibitors (TKI) in patients with non-small cell lung cancer. Serum carcinoembryonic antigen (CEA) levels are also regarded as predictive for the efficacy of EGFR-TKI and EGFR gene mutations. This study analyzed the association between EGFR gene mutations and clinical features, including serum tumor marker levels in lung adenocarcinomas patients. Patients and Methods: A total of 70 lung adenocarcinoma patients with complete clinical data and pathological specimens were investigated. EGFR gene mutations at exons 19 and 21 were assessed. Serum tumor markers were detected by protein chip-chemiluminescence at the corresponding time, and correlations were analyzed. Results: Mutations of the EGFR gene were detected in 27 of the 70 patients and the serum CEA and CA242 concentrations were found to be significantly associated with the incidence of EGFR gene mutations (P<0.05). The AUCs for CEA and CA242 were 0.724 (95% CI: 0.598~0.850, P<0.05) and 0.769 (95% CI: 0.523~0.800, P<0.05) respectively. Conclusions: Serum CEA and CA242 levels are associated with mutations of the EGFR gene in patients with lung adenocarcinomas.

• Proceedings of the Korean Society of Life Science Conference
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• 2008.10a
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• pp.56.1-56.1
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• 2008

• Nuclear Medicine and Molecular Imaging
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• v.42 no.3
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• pp.185-191
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• 2008

While indirect targeting strategies using reporter-genes are taking center stage in current molecular imaging research, another vital strategy has long involved direct imaging of specific receptors using radiolabeled ligands. Recently, there is renewal of immense interest in this area with particular attention to the epidermal growth factor receptor (EGFR), a transmembrane glycoprotein critically involved in the regulation of many cellular functions and malignancies. Recently, two novel classes of EGFR-targeting anticancer drugs have entered clinical trials with great expectations. These are monoclonal antibodies such as cetuximab that target the extracellular domain, and small molecule tyrosine kinase inhibitors such as gefitinib (lressa) and erlotinib (Tarceva) that target the catalytic domain of the receptor. However, early results have showed disappointing survival benefits, disclosing a major challenge for this therapeutic strategy; namely, the need to identify tumors that are most likely to respond to the agents. To address this important clinical issue, several noninvasive imaging techniques are under investigation including radiolabeled probes based on small molecule tyrosine kinase inhibitors, anti-EGFR antibodies, and EGF peptides. This review describes the current status, limitations, and future prospects in the development of radiotracer methods for EGFR imaging.

• Journal of the Korean Applied Science and Technology
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• v.25 no.2
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• pp.240-251
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• 2008

The central role of tyrosine phosphorylation in cell proliferative signaling mechanisms provides another target for chemotherapy. The aim of this research is to develop new quinazoline derivatives that possess the inhibitory activity for depidermal growth factor receptor (EGFR) tyrosine kinase (TK) as protein kinase inhibitors. In this work, a series of new 4-anilino-6-guanidino-7-methoxyquinazoline derivatives (12a-l) were synthesized by the introduction of guanidine moiety at C-6 of quinazoline nucleus and evaluated for their EGFR TK inhibitory activities.