• 동의생리병리학회지
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• 제35권4호
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• pp.117-123
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• 2021

Gefitinib, a first generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI), provides obvious clinical benefit in patients with EGFR-mutant non-small cell lung cancer (NSCLC). However, patients ultimately develop gefitinib resistance which mainly caused by EGFR T790M secondary mutation. In the current study, we investigated whether the root extract of Scutellaria baicalensis (SB) overcomes gefitinib resistance. Gefitinib-resistant H1975 human NSCLC cells (EGFR L858R/T790M double mutant) were treated with gefitinib and/or ethanol extract of SB (ESB) to evaluate the effect of ESB on the gefitinib sensitivity. The cell viability was measured by MTT assay and trypan blue exclusion assay. The colony-forming ability was evaluated by anchorage-dependent colony formation assay. Combined treatment with gefitinib and ESB markedly decreased the cell viability and colony formation than single treatment with gefitinib or ESB in H1975 cells. In addition, cells treated with both gefitinib and ESB exhibited a significant increase of sub-G1 DNA content which indicates apoptotic cells compared with those treated with gefitinib or ESB alone. As a molecular mechanism, combined treatment with gefitinib and ESB strongly downregulated the phosphorylation of ERK and JNK than single treatment with gefitinib or ESB. Taken together, our results demonstrate that ESB sensitizes H1975 cells to gefitinib treatment. We cautiously propose that ESB can be used in combination with gefitinib for the advanced NSCLC patients with acquired resistance to EGFR TKIs.

• Asian Pacific Journal of Cancer Prevention
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• 제13권3호
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• pp.909-914
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• 2012

Background: Gefitinib, a tyrosine kinase inhibitor (TKI) of epidermal growth factor receptor (EGFR), is used both as a single drug and concurrently with whole brain radiotherapy (WBRT) the standard treatment for brain metastases (BM), and is reported to be effective in a few small studies of patients with BM from non-small-cell lung cancer (NSCLC). However, no study has compared the two treatment modalities. This retrospective analysis was conducted to compare the efficacy of gefitinib alone with gefitinib plus concomitant WBRT in treatment of BM from NSCLC. Methods: We retrospectively reviewed 90 patients with BM from NSCLC who received gefitinib alone (250mg/day, gefitinib group) or with concomitant WBRT (40Gy/20f/4w, gefitinib-WBRT group) between September 2005 and September 2009 at Sun Yat-Sen University Cancer Center. Forty-five patients were in each group. Results: The objective response rate of BM was significantly higher in gefitinib-WBRT group (64.4%) compared with gefitinib group (26.7%, P<0.001). The disease control rate of BM was 71.1% in gefitinib-WBRT group and 42.2% in gefitinib group (P=0.006). The median time to progression of BM was 10.6 months in gefitinib-WBRT group and 6.57 months in gefitinib group (P<0.001). The median overall survival(OS) of gefitinib-WBRT and gefitinib alone group was 23.40 months and 14.83 months, respectively (HR, 0.432, P=0.002). Conclusion: Gefitinib plus concomitant WBRT had higher response rate of BM and significant improvement in OS compared with gefitinib alone in treatment of BM from NSCLC.

• Asian Pacific Journal of Cancer Prevention
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• 제15권3호
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• pp.1391-1396
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• 2014

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer and the most common cause of lung cancer death. Currently, the epidermal growth factor receptor inhibitor gefitinib is used for its treatment; however, drug resistance is a major obstacle. Expression of Met has been associated with both primary and acquired resistance to gefitinib, but the mechanisms regulating its expression are not fully understood. Recently, miRNAs such as miR-130a have been shown to play a role in gefitinib resistance, but importance in NSCLC and relationships with Met have not been fully explored. Here we show that miR-130a is over-expressed in gefitinibsensitive NSCLC cell lines, but is low in gefitinib-resistant NSCLC cell lines. Moreover, miR-130a expression was negatively correlated with that of Met. Further analysis revealed that over-expression of miR-130a increased cell apoptosis and inhibited proliferation of NSCLC cells treated with gefitinib, whereas lowering the expression of miR-130a decreased cell apoptosis and promoted cell proliferation after treatment with gefitinib in both gefitinib-sensitive and -resistant NSCLC cell lines, suggesting that miR-130a overcomes gefitinib resistance. We also demonstrated that miR-130a binds to the 3'-UTR of Met and significantly suppresses its expression. Finally, our results showed that over-expressing Met could "rescue" the functions of miR-130a regarding cell apoptosis and proliferation after cells are treated with gefitinib. These findings indicate that the miR-130a/Met axis plays an important role in gefitinib resistance in NSCLC. Thus, the miR-130a/Met axis may be an effective therapeutic target in gefitinib-resistant lung cancer patients.

• BMB Reports
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• 제57권2호
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• pp.104-109
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• 2024

Gefitinib exerts anticancer effects on various types of cancer, such as lung, ovarian, breast, and colon cancers. However, the therapeutic effects of gefitinib on cervical cancer and the underlying mechanisms remain unclear. Thus, this study aimed to explore whether gefitinib can be used to treat cervical cancer and elucidate the underlying mechanisms. Results showed that gefitinib induced a caspase-dependent apoptosis of HeLa cells, which consequently became round and detached from the surface of the culture plate. Gefitinib induced the reorganization of actin cytoskeleton and downregulated the expression of p-FAK, integrin β1 and E-cadherin, which are important in cell-extracellular matrix adhesion and cell-cell interaction, respectively. Moreover, gefitinib hindered cell reattachment and spreading and suppressed interactions between detached cells in suspension, leading to poly (ADP-ribose) polymerase cleavage, a hallmark of apoptosis. It also induced detachment-induced apoptosis (anoikis) in C33A cells, another cervical cancer cell line. Taken together, these results suggest that gefitinib triggers anoikis in cervical cancer cells. Our findings may serve as a basis for broadening the range of anticancer drugs used to treat cervical cancer.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제35권5호
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• pp.287-293
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• 2009

Cell survival is the result of a balance between programmed cell death and cellular proliferation. Cell membrane receptors and their associated signal transducing proteins control these processes. Of the numerous receptors and signaling proteins, epidermal growth factor receptor (EGFR) is one of the most important receptors involved in signaling pathways implicated in the proliferation and survival of cancer cells. EGFR is often highly expressed in human tumors including oral squamous cell carcinomas, and there is increasing evidence that high expression of EGFR is correlated with poor clinical outcome of common human cancers. Therefore, we examined the antiproliferative activity of gefitinib, epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI), in head and neck cancer cell lines. SCC-9, KB cells were cultured and growth inhibition activity of gefitinib was measured with MTT assay. To study influence of gefitinib in cell cycle, we performed cell cycle analysis with flow cytometry. Western blot was done to elucidate the expression of EGFR in cell lines and phosphorylation of EGFR and downstream kinase protein, Erk and Akt. Significant growth inhibition was observed in SCC-9 cells in contrast with KB cells. Also, flow cytometric analysis showed G1 phase arrest only in SCC-9 cells. In Western blot analysis for investigation of EGFR expression and downstream molecule phosphorylation, gefitinib suppressed phosphorylation of EGFR and downstream protein kinase Erk, Akt in SCC-9. However, in EGFR positive KB cells, weak expression of active form of Erk and Akt and no inhibitory activity of phosphorylation in Erk and Akt was observed. The antiproliferative activity of gefitinib was not correlated with EGFR expression and some possibility of phosphorylation of Erk and Akt as a predictive factor of gefitinib response was emerged. Further investigations on more reliable predictive factor indicating gefitinib response are awaited to be useful gefitinib treatment in head and neck cancer patients.

• Tuberculosis and Respiratory Diseases
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• 제61권2호
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• pp.150-156
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• 2006

배 경: 최근 폐암 환자에서 사용하는 표적치료 항암약물인 gefitinib (Iressa)은 종양세포의 표피성장인자 수용체의 티로신 키나아제 활동을 선택적으로 억제하여 종양 세포의 성장에 관여하는 신호를 차단함으로써 치료효과를 나타낸다. Gefitinib 복용에 의한 피부 부작용으로 여드름양 발진, 피부 건조증, 모발 변화 등이 알려져 있다. 대상 및 방법: 2004년 10월부터 2005년 9월까지 화순전남대병원에서 비소세포 폐암으로 진단받고 gefitinib을 복용 중인 환자들 중 피부 부작용이 발생하여 피부과에 의뢰된 환자 23명을 대상으로 임상 양상을 분석하였다. 결 과: 나이는 23-72세였고, 비소세포 폐암의 종류는 선암 17명, 편평상피세포 폐암 5명이었고, 여자 6명, 남자 17명이었다. 가장 흔한 부작용은 여드름양 발진으로 15명(65.2%)에서 발생하였으며, 주로 두피, 얼굴, 가슴, 등 부위에 무증상의 홍반성 구진으로 나타나며 대부분 gefitinib 복용 1달 이내에 발생하였다. 여드름양 발진의 빈도는 gefitinib 치료에 대한 반응과 유의한 상관관계를 보이지 않았고, 조직 형에 따른 차이도 관찰되지 않았다. 피부 소양증은 9명(39.1%)에서 발생하였으며 경도의 전신 소양증이 가장 많았고, 특히 눈 주변의 소양증을 호소하였다. 인설을 동반한 피부 건조증이 6명(26.1%)에서 발생하였고, 손발바닥의 홍반과 표피 박탈이 5명(21.7%), 손톱이나 발톱주변에 조갑주위염이 5명(21.7%)에서 발생하였다. 드물게 모발이 부러지거나 겨드랑이, 오금에 간찰진이 발생하였다. 결 론: 본 연구에서 gefitinib에 의한 다양한 피부 부작용들을 관찰할 수 있었다. Gefitinib을 처방하는 의사들은 피부 부작용에 대한 관심이 필요하며 환자들에게 피부 관리에 대한 교육과 필요한 경우 피부과 의사와 함께 피부 부작용을 치료함으로써 부작용을 경감시킬 수 있었다.

• Tuberculosis and Respiratory Diseases
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• 제71권4호
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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.

• Tuberculosis and Respiratory Diseases
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• 제62권2호
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• pp.144-148
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• 2007

저자 등은 gefitinib 투약 중 발생한 급성호흡곤란으로 사망한 2 예를 경험하였기에 이를 보고하는 바이다.

• Journal of Yeungnam Medical Science
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• 제28권1호
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• pp.31-44
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• 2011

Background: The optimal timing of treatment with EGFR-tyrosine kinase inhibitors (EGFR-TKI) in NSCLC patients has not yet been determined. Methods: We separated 228 patients with advanced /metastatic NSCLC treated with gefitinib into an early gefitinib group (patients who received gefitinib as first- or second-line treatment) and a delayed gefitinib group (patients who received gefitinib as third or fourth-line treatment) and attempted to determine whether the timing of gefitinib treatment affected clinical outcomes. Results: Median overall survival (OS), progression free survival (PFS), and median OS from first-line treatment of advanced/metastatic disease (OSt) for 111 patients in the early gefitinib group were 6.2 months, 3.3 months, and 11.6 months. However, median OS, PFS, and OSt for 84 patients in the delayed gefitinib group were 7.8 months, 2.3 months, and 22.7 months. No differences in OS and PFS were observed between the 2 groups. However, OSt was significantly longer in the delayed gefitnib group. Timing of gefitinib therapy was one of the independent predictors of OSt. Hb ${\geq}$ 10 g/dl, and having never smoked, and ECOG performance status ${\leq}1$ were independent predictors of better PFS. Conclusion：Deferral of gefitinib therapy in patientswith advanced ormetastatic NSCLC may be preferable if they are able to tolerate chemotherapy.

• Tuberculosis and Respiratory Diseases
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• 제66권4호
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• pp.280-287
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• 2009

연구배경: 표피성장인자수용체(epidermal growth factor receptor, EGFR) 티로신 활성효소 억제제(tyrosine kinase inhibitor, TKI)는 진행성 비소세포폐암의 새로운 치료제이다. 몇몇 연구 결과 gefitinib와 erlotinib에 대한 반응률과 반응 예측인자에 차이가 있을 가능성을 제시하였다. 저자들은 한국인 진행성 비소세포폐암에서 gefitinib와 erlotinib의 효과 및 독성을 비교하고 각 약제에 대해 서로 다른 반응 예측인자가 있는지 평가하였다. 방 법: 2003년 7월부터 2009년 2월까지 이화여자대학 교부속병원에서 진행성 비소세포폐암으로 gefitinib 또는 erlotinib로 치료 받은 환자들의 임상정보를 수집하였다. 중앙 생존기간은 Kaplan-Meier법으로 계산하였다. 결 과: 대상 환자는 총 86명이었다(gefitinib군 52명 대 erlotinib군 34명). 나이의 중앙값은 64세였고 53명(62%)이 남자였다. 86명 중 83명에서 반응평가가 가능했으며, 83명 중 35명이 반응을 보였고 12명이 안정성 질환이었으며 36명이 진행성 질환으로, 치료 반응률이 42%였고 질병 조절률이 57%였다. 중앙 추적관찰기간 502일 동안, 진행까지의 중앙기간은 129일이었으며 중앙 생존기간은 259일이었다. 치료 반응률(gefitinib 44% 대 erlotinib 39%, p=0.678), 중앙 생존기간(gefitinib 301일 대 erlotinib 202일, p=0.151) 및 병의 진행까지 기간의 중앙값(gefitinib 136일 대 erlotinib 92일, p=0.672)은 두 군 사이에 차이가 없었다. 두 약제는 비슷한 독성을 보였다. Cox 회귀모형을 이용한 다변수분석에서 선암이 생존과 관련된 독립적인 예후인자였다(상대위험도: 0.487, 95% 신뢰구간: 0.292~0.811, p=0.006). 아집단 분석 결과 두 약제에 대한 서로 다른 반응 예측인자는 없었다. 결 론: Gefitinib와 erlotinib 사이에 반응률, 생존기간, 진행까지의 기간 및 독성에 차이는 없었다. 각 약제에 대한 특이적인 반응 예측인자도 없었다.