• Bulletin of the Korean Chemical Society
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• 제34권6호
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• pp.1917-1920
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• 2013

• International Journal of Oral Biology
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• 제46권4호
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• pp.176-183
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• 2021

Oral squamous cell carcinoma (OSCC) metastasis is characterized by distant metastasis and local recurrence. Combined chemotherapy with cisplatin and 5-fluorouracil is routinely used to treat patients with OSCC, and the combined use of gefitinib with cytotoxic drugs has been reported to enhance the sensitivity of cancer cells in vitro. However, the development of drug resistance because of prolonged chemotherapy is inevitable, leading to a poor prognosis. Therefore, understanding alterations in signaling pathways and gene expression is crucial for overcoming the development of drug resistance. However, the altered characterization of Ca²⁺ signaling in drug-resistant OSCC cells remains unclear. In this study, we investigated alterations in intracellular Ca²⁺ ([Ca²⁺]_i) mobilization upon the development of gefitinib resistance in human tongue squamous carcinoma cell line (HSC)-3 and HSC-4 using ratiometric analysis. This study demonstrated the presence of altered epidermal growth factor- and purinergic agonist-mediated [Ca²⁺]_i mobilization in gefitinib-resistant OSCC cells. Moreover, Ca²⁺ content in the endoplasmic reticulum, store-operated calcium entry, and lysosomal Ca²⁺ release through the transient receptor potential mucolipin 1, were confirmed to be significantly reduced upon the development of apoptosis resistance. Consistent with [Ca²⁺]_i mobilization, we identified modified expression levels of Ca²⁺ signaling-related genes in gefitinib-resistant cells. Taken together, we propose that the regulation of [Ca²⁺]_i mobilization and related gene expression can be a new strategy to overcome drug resistance in patients with cancer.

• Biomolecules & Therapeutics
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• 제31권2호
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• pp.200-209
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• 2023

Patients with non-small-cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) amplification or sensitive mutations initially respond to the tyrosine kinase inhibitor gefitinib, however, the treatment becomes less effective over time by resistance mechanism including mesenchymal-epithelial transition (MET) overexpression. A therapeutic strategy targeting MET and EGFR may be a means to overcoming resistance to gefitinib. In the present study, we found that picropodophyllotoxin (PPT), derived from the roots of Podophyllum hexandrum, inhibited both EGFR and MET in NSCLC cells. The antitumor efficacy of PPT in gefitinib-resistant NSCLC cells (HCC827GR), was confirmed by suppression of cell proliferation and anchorage-independent colony growth. In the targeting of EGFR and MET, PPT bound with EGFR and MET, ex vivo, and blocked both kinases activity. The binding sites between PPT and EGFR or MET in the computational docking model were predicted at Gly772/Met769 and Arg1086/Tyr1230 of each ATP-binding pocket, respectively. PPT treatment of HCC827GR cells increased the number of annexin V-positive and subG1 cells. PPT also caused G2/M cell-cycle arrest together with related protein regulation. The inhibition of EGFR and MET by PPT treatment led to decreases in the phosphorylation of the downstream-proteins, AKT and ERK. In addition, PPT induced reactive oxygen species (ROS) production and GRP78, CHOP, DR5, and DR4 expression, mitochondrial dysfunction, and regulated involving signal-proteins. Taken together, PPT alleviated gefitinib-resistant NSCLC cell growth and induced apoptosis by reducing EGFR and MET activity. Therefore, our results suggest that PPT can be a promising therapeutic agent for gefitinib-resistant NSCLC.

• International Journal of Oral Biology
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• 제48권1호
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• pp.1-7
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• 2023

Oral squamous cell carcinoma (OSCC), which accounts for approximately 90% of oral cancers, has a high rate of local recurrence and a poor prognosis despite improvements in treatment. Exosomes released from OSCC cells promote cell proliferation and metastasis. Although it is clear that the biogenesis of exosomes is mediated by the endosomal sorting complex required for transport (ESCRT) machinery, the gene expression pattern of ESCRT, depending on the cell type, remains elusive. The exosomal release from the human OSCC cell lines, HSC-3 and HSC-4, and their corresponding gefitinib-resistant sub-cell lines, HSC-3/GR and HSC-4/GR, was assessed by western blot and flow cytometry. The levels of ESCRT machinery proteins, including Hrs, Tsg101, and Alix, and whole-cell ubiquitination were evaluated by western blot. We observed that the basal level of exosomal release was higher in HSC-3/GR and HSC-4/GR cells than in HSC-3 and HSC-4 cells, respectively. Long-term gefitinib exposure of each cell line and its corresponding gefitinib-resistant sub-cell line differentially induced the expression of the ESCRT machinery. Furthermore, whole-cell ubiquitination and autophagic flux were shown to be increased in gefitinib-treated HSC-3 and HSC-4 cells. Our data indicate that the expression patterns of the ESCRT machinery genes are differentially regulated by the characteristics of cells, such as intracellular energy metabolism. Therefore, the expression patterns of the ESCRT machinery should be considered as a key factor to improve the treatment strategy for OSCC.

• 종양간호연구
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• 제9권2호
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• pp.77-85
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• 2009

Purpose: The purpose of this study was to identify symptom cluster experienced by patients with advanced non-small cell lung cancer (NSCLC) on gefitinib treatment. In addition, this study assessed the patterns in severity of the symptom cluster and differences in quality of life (QOL) and function among subgroups by the severity of symptom cluster. Methods: This study was conducted as a secondary analysis of symptoms of 72 patients from a mother study. Factor analysis was used to identify symptom clusters measured with EORTC QLQ-C30 and LC13 symptom related items. Results: Three symptom clusters were identified: cluster 1 was comprised of fatigue, anorexia and dysphagia; cluster 2 of dyspnea, cough and insomnia; and cluster 3 of pain, constipation and nausea/vomiting. These three symptom clusters were improved one week after gefitinib administration. The group with more severe symptom clusters showed significantly lower QOL and function than the group with less severe symptom clusters. Conclusion: Since symptom clusters experienced by the patients with advanced NSCLC influenced on the QOL and function, it is important for nurses to understand and observe their symptom clusters. In addition, there is an necessity to develop nursing interventions to effectively care patients with the symptom clusters.

• Asian Pacific Journal of Cancer Prevention
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• 제14권7호
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• pp.4205-4208
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• 2013

Objective: The aim of this study was to explore change and significance of serum carcino-embryonic antigen (CEA) before and after gefitinib therapy in patients with advanced non-small-cell lung cancer (NSCLC). Methods: Forty patients with advanced NSCLCs in III~IV stages were selected as study objects given gefitinib therapy combined with routine local radiotherapy until tumor progression or intolerable toxicity. After treatment, all patients were divided into control and non-control groups according to the results of evaluation based on RECIST 1.1 (Response Evaluation Criteria in Solid Tumors in 2009). Peripheral fasting blood from all patients was collected in the early morning and serum CEA was assessed by electro-chemiluminescence immunoassay (ECLIA) before and after treatment. Before treatment, patients were divided into high CEA group (CEA level > 50 ng/mL) and low CEA group (CEA level ${\leq}$ 50 ng/mL). Adverse reactions were noted and progression-free survival (PFS) in both groups was recorded after long-term follow-up that ended in December, 2012. Results: There was no difference between control and non-control groups in CEA level before treatment (P>0.05), whereas serum CEA decreased more markedly lower in the control group after treatment (P<0.01). All patients were divided into high CEA group (26) and low CEA group (14) according to serum CEA level. There was no statistically significant difference between two groups in adverse reactions (P>0.05) but the rate in former group was lower. Additionally, survival rates at 9 and 12 months in high CEA group were clearly higher than in the low CEA group (P<0.01). Conclusions: Serum CEA level can serve as a biochemical index to evaluate the prognosis with gefitinib treatment for NSCLC.

• 대한약침학회지
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• 제19권3호
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• pp.259-263
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• 2016

Lung cancer has a high mortality rate and is often diagnosed at the metastatic stage. Gefitinib is a targeted molecular therapeutic drug used to treat patients with non-small-cell lung cancer (NSCLC). Korean herbal medicines may also have therapeutic efficacy against lung cancer, reduce the side effects associated with chemotherapy, and improve patient quality of life (QOL). This case report describes the effects of a Korean herbal medicine regimen combined with gefitinib in a patient with NSCLC and bone metastasis. The Korean herbal medicine regimen included woohwanggeosa-dan, hwanggibujeong-dan and geonchilgyebok-jeong. The computed tomography (CT) findings showed that following combination treatment, the size of the tumor was markedly decreased without serious adverse events. Moreover, the Eastern Cooperative Oncology Group (ECOG) performance status was improved and cancer-related pain was decreased. These results suggest that a combination of Korean herbal medicines and gefitinib may be an effective therapeutic option for patients with advanced NSCLC and bone metastasis. Further studies are needed to examine the mechanism and the clinical efficacy of Korean herbal medicines against NSCLC.

• Bulletin of the Korean Chemical Society
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• 제34권12호
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• pp.3782-3786
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• 2013

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer and that accounts for 85% of lung cancer patients. Although several EGFR-targeted drugs have been developed in the treatment of NSCLC, the clinical efficacy of EGFR-targeted drugs in NSCLC is limited by the occurrence of drug resistance. In this regard, Hsp90 represents great promise as a therapeutic target of cancer due to its potential to simultaneously disable multiple signaling pathways. In this study, we discovered that a natural product, flavokawain B disrupted Hsp90 chaperoning function and impaired the growth of gefitinib-resistant non-small cell lung cancer (H1975). The result suggested that flavokawain B could serve as a potential lead compound to overcome the drug resistance in cancer chemotherapy.

• Tuberculosis and Respiratory Diseases
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• 제73권6호
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• pp.303-311
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• 2012

Background: This study was designed to analyze the efficacy of gefitinib as a second-line therapy, according to the clinical characteristics in Korean patients with non-small-cell lung cancer (NSCLC). Methods: In this Phase IV observational study, we recruited patients, previously failed first-line chemotherapy, who had locally advanced or metastatic NSCLC, and who were found to be either epidermal growth factor receptor (EGFR) mutation-positive or satisfied 2 or more of the 3 characteristics: adenocarcinoma, female, and non-smoker. These patients were administered with gefitinib 250 mg/day, orally. The primary endpoints were to evaluate the objective response rate (ORR) and to determine the relationship of ORRs, depending on each patient's characteristics of modified intent-to-treat population. Results: A total of 138 patients participated in this study. One subject achieved complete response, and 42 subjects achieved partial response (ORR, 31.2%). The subgroup analysis demonstrated that the ORR was significantly higher in patients with EGFR mutation-positive, compared to that of EGFR mutation-negative (45.8% vs. 14.0%, p=0.0004). In a secondary efficacy variable, the median progression-free survival (PFS) was 5.7 months (95% confidence interval, 3.9~8.4 months) and the 6-month PFS and overall survival were 49.6% and 87.9%, respectively. The most common reported adverse events were rash (34.4%), diarrhea (26.6%), pruritus (17.5%), and cough (15.6%). Conclusion: Gefitinib was observed in anti-tumor activity with favorable tolerability profile as a second-line therapy in these selected patients. When looking at EGFR mutation status, EGFR mutation-positive showed strong association with gefitinib by greater response and prolonged PFS, compared with that of EGFR mutation-negative.

• Journal of Yeungnam Medical Science
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• 제33권1호
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• pp.64-67
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• 2016

We report on a 64-year-old man with leptomeningeal metastasis (LM) from an epidermal growth factor receptor (EGFR)-mutated adenocarcinoma of the lung. He was treated with paclitaxel, cisplatin. After completion of chemotherapy, he complained of headache, nausea, and vomiting. EGFR-mutated tumor cells were identified from the cerebrospinal fluid (CSF). Second-line therapy with gefitinib, methotrexate was started. After receiving gefitinib for 4 weeks, he had no more headaches or vomiting. Eleven months after initiation of gefitinib, he developed headache and nausea. Chest computed tomography showed aggravation of bone metastasis. Third-line therapy was started with gemcitabine and carboplatin. Two weeks later, he experienced disorientation. After a fourth relapse within the central nervous system, the therapy was switched to erlotinib and significant improvement of LM was achieved. This case shows that LM can be diagnosed by detecting EGFR mutation in CSF and EGFR tyrosine kinase inhibitors are effective for LM from EGFR mutant non-small cell lung cancer.