• Proceedings of the PSK Conference
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• 2000.04a
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• pp.162.1-162.1
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• 2000

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.1
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• pp.255-260
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• 2012

Patients with non-small cell lung cancer (NSCLC) who have activating epidermal growth factor receptor (EGFR) mutations derive clinical benefit from treatment with EGFR-tyrosine kinase inhibitors ((EGFR-TKIs)-namely gefitinib and erlotinib. However, these patients eventually develop resistance to EGFR-TKIs. Despite the fact that this acquired resistance may be the result of a secondary mutation in the EGFR gene, such as T790M or amplification of the MET proto-oncogene, there are other mechanisms which need to be explored. MicroRNAs (miRs) are a class of small non-coding RNAs that play pivotal roles in tumorigenesis, tumor progression and chemo-resistance. In this study, we firstly successfully established a gefitinib resistant cell line-HCC827/GR, by exposing normal HCC827 cells (an NSCLC cell line with a 746E-750A in-frame deletion of EGFR gene) to increasing concentrations of gefitinib. Then, we found that miR-214 was significantly up-regulated in HCC827/GR. We also showed that miR-214 and PTEN were inversely expressed in HCC827/GR. Knockdown of miR-214 altered the expression of PTEN and p-AKT and re-sensitized HCC827/GR to gefitinib. Taken together, miR-214 may regulate the acquired resistance to gefitinib in HCC827 via PTEN/AKT signaling pathway. Suppression of miR-214 may thus reverse the acquired resistance to EGFR-TKIs therapy.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.11
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• pp.4493-4497
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• 2014

Background: Epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer (NSCLC) can predict the clinical response to tyrosine kinase inhibitor (TKI) therapy. However, EGFR mutations may be different in primary tumors (PT) and metastatic lymph nodes (MLN). The aim of this study was to compare EGFR mutations between PT and the corresponding MLN in NSCLC patients, and provide some guidelines for clinical treatment using TKI therapy. Materials and Methods: A systematic review and meta-analysis was performed with several research databases. Relative risk (RR) with the 95% confidence interval (CI) were used to investigate the EGFR mutation status between PT and the corresponding MLN. A random-effects model was used. Results: 9 publications involving 707 patients were included in the analysis. It was found that activation of EGFR mutations identified in PT and the corresponding MLN was 26.4% (187/707) and 19.9% (141/707), respectively. The overall discordance rate in our meta-analysis was 12.2% (86/707). The relative risk (RR) for EGFR mutation in PT relative to MLN was 1.33 (95%CI: 1.10-1.60; random-effects model). There was no significant heterogeneity between the studies ($I^2$=5%, p=0.003). Conclusions: There exists a considerable degree of EGFR mutation discrepancy in NSCLC between PT and corresponding MLN, suggesting that tumor heterogeneity might arise at the molecular level during the process of metastasis.

• Tuberculosis and Respiratory Diseases
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• v.71 no.4
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• pp.259-265
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• 2011

Background: Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors, gefitinib and erlotinib, are effective therapies for non-small cell lung cancer (NSCLC) patients whose tumors harbor somatic mutations in EGFR. The mutations are, however, only found in about 30% of Asian NSCLC patients and all patients ultimately develop resistance to these agents. Ionizing radiation has been shown to induce autophosphorylation of EGFR and activate its downstream signaling pathways. In the present study, we have tested whether the effect of gefitinib treatment can be enhanced after ionizing radiation. Methods: We compared the PC-9 and A549 cell line with its radiation-resistant derivatives after gefitinib treatment with cell proliferation and apoptosis assay. We also analyzed the effect of gefitinib after ionizing radiation in PC-9, A549, and NCI-H460 cells. Cell proliferation was determined by MTT assay and induction of apoptosis was evaluated by flow cytometry. Caspase 3 activation and PARP cleavage were evaluated by western blot analysis. Results: PC-9 cells having mutated EGFR and their radiation-resistant cells showed no significant difference in cell viability. However, radiation-resistant A549 cells were more sensitive to gefitinib than were their parental cells. This was attributable to an increased induction of apoptosis. Gefitinib-induced apoptosis increased significantly after radiation in cells with wild type EGFR including A549 and NCI-H460, but not in PC-9 cells with mutated EGFR. Caspase 3 activation and PARP cleavage accompanied these findings. Conclusion: The data suggest that gefitinib-induced apoptosis could increase after radiation in cells with wild type EGFR, but not in cells with mutated EGFR.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.5
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• pp.396-402
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• 2011

Introduction: Epidermal growth factor is a single-chain polypeptide consisting of 53 amino acids with potent mitogenic activity that stimulates the proliferation of a range of normal and neoplastic cells through an interaction with its specific receptor (epidermal growth factor receptor, EGFR). This interaction plays a key role in tumor progression including the induction of tumor cell proliferation. An increased EGFR copy number have been associated with a favorable response to EGFR tyrosine kinase inhibitors therapy. In contrast, K-ras mutations tend to predict a poor response to such therapy. The aim of this study was to determine the correlation between the clinicopathological factors and the up-regulation of EGFR expression and Kras mutations in oral squamous cell carcinoma. Materials and Methods: This study examined the immunohistochemical staining of EGFR, K-ras mutation detection with peptide nucleic acid (PNA)-based real-time polymerase chain reaction (PCR) clamping in 20 specimens from 20 patients with oral squamous cell carcinoma. Results: 1. In the immunohistochemical study of poorly differentiated and invasive oral squamous cell carcinoma, a high level of EGFR staining was observed. The correlation between immunohistochemical EGFR expression and histological differentiation, as well as the tumor size of the specimens was significant (Pearson correlation analysis, significance [r] >0.5, P<0.05). 2. In PNA-based real-time PCR clamping analysis, a K-ras mutation was not detected in all specimens. Conclusion: These findings suggest that the up-regulation of the EGFR may play a role in the progression and invasion of oral squamous cell carcinoma that is, independent of a K-ras mutation.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.16
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• pp.7071-7076
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• 2015

Epidermal growth factor receptor (EGFR) is one of the targeted molecular markers in many cancers including lung malignancies. Gefitinib and erlotinib are two available therapeutics that act as specific inhibitors of tyrosine kinase (TK) domains. We performed a case-control study with formalin-fixed paraffin-embedded tissue blocks (FFPE) from tissue biopsies of 167 non-small cell lung carcinoma (NSCLC) patients and 167 healthy controls. The tissue biopsies were studied for mutations in exons 18-21 of the EGFR gene. This study was performed using PCR followed by DNA sequencing. We identified 63 mutations in 33 men and 30 women. Mutations were detected in exon 19 (delE746-A750, delE746-T751, delL747-E749, delL747-P753, delL747-T751) in 32 patients, exon 20 (S786I, T790M) in 16, and exon 21 (L858R) in 15. No mutations were observed in exon 18. The 63 patients with EFGR mutations were considered for upfront therapy with oral tyrosine kinase inhibitor (TKI) drugs and have responded well to therapy over the last 15 months. The control patients had no mutations in any of the exons studied. The advent of EGFR TKI therapy has provided a powerful new treatment modality for patients diagnosed with NSCLC. The study emphasizes the frequency of EGFR mutations in NSCLC patients and its role as an important predictive marker for response to oral TKI in the south Indian population.

• Tuberculosis and Respiratory Diseases
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• v.78 no.4
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• pp.315-320
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• 2015

Background: The efficacy of epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) therapy can be measured based on the rate of treatment response, based on the Response Evaluation Criteria in Solid Tumors (RECIST) criteria or progression-free survival (PFS). However, there are some patients harboring sensitive EGFR mutations who responded poorly to EGFR-TKI therapy. In addition, there is variability in the PFS after EGFR-TKI treatment. Methods: We performed a retrospective analysis of the medical records of 85 patients with non-small cell lung cancer, who had achieved a stable disease or better response at the first evaluation of treatment response, after receiving a 2-month course of gefitinib. We calculated the tumor shrinkage rate (TSR) by measuring the longest and perpendicular diameter of the main mass on computed tomography before, and 2 months after, gefitinib therapy. Results: There was a significant positive correlation between the TSR and PFS (R=0.373, p=0.010). In addition, a simple linear regression analysis showed that the TSR might be an indicator for the PFS ($B{\pm}standard$ error, $244.54{\pm}66.79$; p=0.001). On univariate analysis, the sex, histologic type, smoking history and the number of prior chemotherapy regimens, were significant prognostic factors. On multivariate regression analysis, both the TSR (${\beta}$=0.257, p=0.029) and adenocarcinoma (${\beta}$=0.323, p=0.005) were independent prognostic factors for PFS. Conclusion: Our results showed that the TSR might be an early prognostic indicator for PFS in patients receiving EGFRTKI therapy.

• Tuberculosis and Respiratory Diseases
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• v.55 no.1
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• pp.21-30
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• 2003

Background : Mucin synthesis in airways has been reported to be regulated by the epidermal growth factor receptor (EGFR) system. Epidermal growth factor receptor transactivation was identified as a critical element in G-protein-coupled receptors (GPCRs)-induced mitogenic signaling. EGF receptor transactivation by G-protein-coupled receptors requires metalloproteinase cleavage of proHB-EGF. This study was hypothesized that lipopolysaccharide (LPS)-induced mucin production associates with epidermal growth factor receptor transactivation, and MUC5AC production associates with epidermal growth factor receptor transactivation by G-protein-coupled receptors that regulates by metalloproteinase. Method : MUC5AC mucin production was examined in NCI-H292 cells and MUC5AC protein synthesis was assessed using ELISA. For the evaluation of mechanism of LPS-induced MUC5AC production, $TNF{\alpha}$ was measured using ELISA with or without pretreatment of heterotrimeric G-protein inhibitor, mastoparan. MUC5AC protein was measure with pretreatment of polyclonal $TNF{\alpha}$ antibody or mastoparan on LPS-induced MUC5AC production. For the evaluation of relation of G-protein and MUC5AC production, G-protein stimulant, mastopara-7, or matrix metalloproteinase, ADAM10, was added to NCI-H292 cells. MUC5AC protein was measure with pretreatment of polyclonal EGF antibody on mastoparan-7-induced MUC5AC production. Results : LPS alone did not increase significantly MUC5AC production. LPS with $TNF{\alpha}$ induced dose-dependently MUC5AC production in NCI-H292 cells. LPS increased dose-dependently $TNF{\alpha}$ secretion, which was inhibited by mastoparan. LPS with $TNF{\alpha}$-induced MUC5AC production was inhibited by neutralizing polyclonal $TNF{\alpha}$ antibody, mastoparan or AG 1472. Mastoparan-7 or ADAM10 increased dose-dependently MUC5AC production, which was inhibited by polyclonal neutralizing EGF antibody. Conclusion : In LPS-induced MUC5AC synthesis, LPS causes $TNF{\alpha}$ secretion, which induces EGFR expression. EGFR tyrosine kinase phosphorylation result in MUC5AC production. EGF-R transactivation by G-protein-coupled receptors requires matrix metalloproteinase cleavage of proHB-EGF.

• The Journal of the Korean life insurance medical association
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• v.31 no.1
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• pp.34-36
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• 2012

Lung cancer such as small cell lung cancer(SCLC) and non small cell lung cancer(NSCLC) have high mortality rate, so, we insurance doctors have little interest in their risk. But nowadays there's a lot of development in targeted therapy of NSCLC. Screening by CT scanning and early resection strategy also shows better prognosis. It is helpful for underwriters and insurance doctors to review the current development of targeted therapy of NSCLC and estimation of extra-risk of early lung cancer. The preferred treatment option for patients whose tumors contain EGFR-activating mutations are one of the EGFR-directed tyrosine kinase inhibitors, such as gefitinib or erlotinib. In patients with NSCLC whose tumors harboured an ALK rearrangement, there was 61% objective response rate to crizotinib in the phase 1 study. The median survival progression-free survival was 10 months. Mortality analysis of early lung cancer who were detected by CT screening, MR of 105% and EDR of 1‰ were calculated.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.4
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• pp.2413-2419
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• 2013

Background: Use of epidermal growth factor receptor inhibitors (EGFR-TKIs ) is now standard for non-small-cell lung cancer (NSCLC). However, the effects of EGFR-TKIs in maintenance therapy for advanced NSCLC patients are still unclear. The preent meta-analysis was performed to examine pooled data of randomized control trials (RCT) where EGFR-TKIs were compared against placebo in maintenance regimens for patients with advanced NCSLC to quantify potential benefits and determine safety. Methods: Several data bases were searched, including PubMed, EMBASE and CENTRAL, and we performed an internet search of conference literature. The endpoints were objective response rates (ORR), progression-free survival (PFS) and overall survival (OS). We performed a meta-analysis of the published data, using Comprehensive Meta Analysis software (Version 2.0). with a fixed effects model and an additional random effects model, when applicable. The results of the meta-analysis are expressed as hazard ratios (HRs) or risk ratios (RRs), with their corresponding 95% confidence intervals (95%CIs). Results: The final analysis included six trials, covering 3,758 patients. Compared with placebo, EGFR-TKIs maintenance therapy improved ORR and PFS for patients with advanced NSCLC, the difference being statistically significant (P<0.05), but proved unable to prolong patients' OS. The main adverse reactions were diarrhea and rashes. Conclusion: EGFR-TKIs demonstrated encouraging efficacy, safety and survival when delivered as maintenance therapy for patients with advanced NSCLC after first-line chemotherapy, especially for the patients who had adenocarcinomas, were female, non-smokers and patients with EGFR gene mutations.