• Tuberculosis and Respiratory Diseases
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• 제51권2호
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• pp.122-134
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• 2001

연구배경 : 종양 세포들이 항암제에 대하여 저항을 나타내는 기전인 'apoptosis에 대한 저항'에 NF-${\kappa}B$의 활성이 중요한 역할을 하리라 생각되고 있다. 즉, NF-${\kappa}B$가 종양세포의 apoptosis를 억제하는 작용을 일으킴으로써 종양 세포의 생존에 유리하게 작용하고 있음이 제시되 고 있다. 방 법 : 본 연구에서는 비소세포폐암에 대한 항암 치료의 내성에 대하여 외부 자극으로 분해되지 않는 $I{\kappa}B{\alpha}$-SR의 삽입으로 NF-${\kappa}B$의 활성을 억제시키고 이로 인해 항암제에 대한 폐암세포주의 감수성이 증가하는지 여부를 밝혀 보고자 하였다. 결 과 : 비소세포폐암 세포주로 NCI H157, NCI H460 세포주를 이용하였고, Ad-$I{\kappa}B{\alpha}$-SR를 transduction 한 후 cisplatin을 처치한 군에서 NF-${\kappa}B$의 핵 내로의 이동이 억제되었으며 대조군과 비교시 $IC_{50}$이 2-3배 정도 유의하게 낮아짐을 관찰하였다. 또한 paclitaxel의 경우에도 Ad-$I{\kappa}B{\alpha}$-SR로 감염된 폐암세포주는 대조군과 비교시 IC50이 2배 정도 유의하게 낮아짐을 관찰하였다. 이러한 항암제에 대한 감수성의 증가의 기전으로 cisplatin의 경우는 $I{\kappa}B{\alpha}$-SR의 이입이 NF-${\kappa}B$의 활성을 억제 함으로 인한 apoptosis의 증대 때문인 것으로보인다. 결 론 : 폐암세포주에서 Ad-$I{\kappa}B{\alpha}$-SR transduction은 Clsplatin, paclitaxel에 대한 폐암세포주의 감수성을 증가시킴으로 앞으로 폐암을 치료하는데 있어 새로운 치료 방법이 될 수 있을 것으로 보인다.

• Tuberculosis and Respiratory Diseases
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• 제75권3호
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• pp.95-103
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• 2013

Background: Small cell lung cancer (SCLC) transformation during epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) treatment in lung cancer has been suggested as one of possible resistance mechanisms. Methods: We evaluated whether SCLC transformation or neuroendocrine (NE) differentiation can be found in the cell line model. In addition, we also investigated its effect on responses to conventional chemotherapeutic drugs of the SCLC treatment. Results: Resistant cell lines to various kinds of EGFR-TKIs such as gefitinib, erlotinib, CL-387,785 and ZD6474 with A549, PC-9 and HCC827 lung adenocarcinoma cell lines were established. Among them, two resistant cell lines, A549/GR (resistant to gefitinib) and PC-9/ZDR (resistant to ZD6474) showed increased expressions of CD56 while increased synaptophysin, Rb, p16 and poly(ADP-ribose) polymerase were found only in A549/GR in western blotting, suggesting that NE differentiation occurred in A549/GR. A549/GR cells were more sensitive to etoposide and cisplatin, chemotherapeutic drugs for SCLC, compared to parental cells. Treatment with cAMP and IBMX induced synaptophysin and chromogranin A expression in A549 cells, which also made them more sensitive to etoposide and cisplatin than parental cells. Furthermore, we found a tissue sample from a patient which showed increased expressions of CD56 and synaptophysin after development of resistance to erlotinib. Conclusion: NE differentiation can occur during acquisition of resistance to EGFR-TKI, leading to increased chemosensitivity.

• Asian Pacific Journal of Cancer Prevention
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• 제15권17호
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• pp.7303-7307
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• 2014

Objective: To explore the clinical efficacy of gemcitabine concomitant with nedaplatin and drug resistance in the treatment of non-small cell lung cancer (NSCLC) and associated molecular predicators. Materials and Methods: A total of 68 patients diagnosed with NSCLC by histology served as the study objects and were randomly divided into an observation group treated with gemcitabine concomitant with nedaplatin and a control group with cisplatin concomitant with gemcitabine, 34 cases for each group. Short-term and long-term efficacies, adverse responses as well as the expression of nucleotide excision repair cross complementing 1 (ERCC1), ribonucleotide reductase subunit M1 (RRM1) and lung resistance-related protein (LRP) in NSCLC tissues in both groups were assessed. Results: The short-term objective response rate (ORR) and disease control rate (DCR) were 35.3% (12/34) and 76.5% (26/34) in the observation group and 38.2% (13/34) and 85.3% (29/34) in the control group, respectively, the differences not being statistically significant. The time to progression (TTP) in both groups were 1~12 months, while the median TTP was 135 d and 144 d, respectively. Though the survival was slightly higher in the control group, there were no significant differences in TTP and survival time. The rates of decreased hemoglobin, vomiting and nausea as well as renal toxicity were evidently lower in the observation group, while other adverse responses demonstrated no significant difference. The positive expression rates of ERCC1, RRM1 and LRP were 47.1% (16/34), 61.8% (21/34) and 64.7% (22/34) in the observation group, respectively. Compared with negative ERCC1 expression, ORR had decreasing trend and the overall survival time (OS) decreased significantly in patients with positive ERCC1 expression, which were markedly decreased by the positive expressions of RRM1 and LRP. Conclusions: Gemcitabine concomitant with nedaplatin has significant effects in the treatment of NSCLC, with an adverse response rate obviously lower than for cisplatin concomitant with gemcitabine, suggesting that wider use in the clinic is warranted. Additionally, the positive expressions of ERCC1, RRM1 and LRP may increase patient drug resistance, so they can be applied as the chemotherapeutic predicators to guide individualized therapy of NSCLC patients.

• Molecules and Cells
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• 제42권3호
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• pp.270-283
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• 2019

This study was aimed to explore if lncRNA MALAT1 would modify chemo-resistance of non-small cell lung cancer (NSCLC) cells by regulating miR-197-3p and p120 catenin (p120-ctn). Within this investigation, we totally recruited 326 lung cancer patients, and purchased 4 NSCLC cell lines of A549, H1299, SPC-A-1 and H460. Moreover, cisplatin, adriamycin, gefitinib and paclitaxel were arranged as chemotherapies, and half maximal inhibitory concentration (IC50) values were calculated to evaluate the chemo-resistance of the cells. Furthermore, mice models of NSCLC were also established to assess the impacts of MALAT1, miR-197-3p and p120-ctn on tumor growth. Our results indicated that MALAT1 and miR-197-3p were both over-expressed within NSCLC tissues and cells, when compared with normal tissues and cells (P < 0.05). The A549, H460, SPC-A-1 and SPC-A-1 displayed maximum resistances to cisplatin ($IC50=15.70{\mu}g/ml$), adriamycin ($IC50=5.58{\mu}g/ml$), gefitinib ($96.82{\mu}mol/L$) and paclitaxel (141.97 nmol/L). Over-expression of MALAT1 and miR-197-3p, or under-expression of p120-ctn were associated with promoted viability and growth of the cancer cells (P < 0.05), and they could significantly strengthen the chemo-resistance of cancer cells (P < 0.05). MALAT1 Wt or p120-ctn Wt co-transfected with miR-197-3p mimic was observed with significantly reduced luciferase activity within NSCLC cells (P < 0.05). Finally, the NSCLC mice models were observed with larger tumor size and weight under circumstances of over-expressed MALAT1 and miR-197-3p, or under-expressed p120-ctn (P < 0.05). In conclusion, MALAT1 could alter chemo-resistance of NSCLC cells by targeting miR-197-3p and regulating p120-ctn expression, which might assist in improvement of chemo-therapies for NSCLC.

• Asian Pacific Journal of Cancer Prevention
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• 제14권12호
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• pp.7375-7379
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• 2013

The main aim of this study was to investigate the roles of GST-${\pi}$ and $pol{\beta}$ genes in the chemoresistance of esophageal carcinoma cells. Eukaryotic expression vectors containing each gene were constructed and transfected into EC9706 cells, and the biological effects of the two genes assessed based on a resistance index. We additionally investigated the in vitro and in vivo anti-resistance effects of GST-${\pi}$ and $pol{\beta}$ genes using recombinant lentiviruses carrying siRNAs against the two genes. Our results showed that upregulation of GST-${\pi}$ and $pol{\beta}$ genes suppresses chemosensitivity of esophageal carcinoma cells to cisplatin, while downregulation of these two genes with RNAi technology reverses this chemoresistance. Multi-site injection of recombinant lentivirus targeting the GST-${\pi}$ gene into transplanted cDDP tumors effectively reversed their chemoresistant phenotype. However, the same treatment against the $pol{\beta}$ gene did not lead to significant efficacy against chemoresistance.

• Journal of Microbiology and Biotechnology
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• 제27권8호
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• pp.1367-1378
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• 2017

Epigenetic alterations such as DNA methylation, histone acetylation, and chromatin remodeling can control gene expression by regulating gene transcription. DNA methylation is one of the frequent epigenetic events that play important roles in cancer development. Cancer cells can gain significant resistance to anticancer drugs and escape programmed cell death through major epigenetic changes, including DNA methylation. To date, several research groups have identified instances of both (i) hypermethylation of tumor suppressor genes, and (ii) global hypomethylation of oncogenes. These changes in DNA methylation status could be used as biomarkers for the diagnosis and prognosis of cancer patients undergoing chemotherapies or other clinical therapies. Herein, we describe genes for which methylation is dependent upon anticancer drug resistance in patients with gastric cancer; we then suggest a significant epigenetic target to focus on for overcoming anticancer drug resistance.

• 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.

• The Korean Journal of Physiology and Pharmacology
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• 제22권5호
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• pp.513-523
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• 2018

The tumor microenvironment greatly influences cancer cell characteristics, and acidic extracellular pH has been implicated as an essential factor in tumor malignancy and the induction of drug resistance. Here, we examined the characteristics of gastric carcinoma (GC) cells under conditions of extracellular acidity and attempted to identify a means of enhancing treatment efficacy. Acidic conditions caused several changes in GC cells adversely affecting chemotherapeutic treatment. Extracellular acidity did inhibit GC cell growth by inducing cell cycle arrest, but did not induce cell death at pH values down to 6.2, which was consistent with down-regulated cyclin D1 and up-regulated p21 mRNA expression. Additionally, an acidic environment altered the expression of atg5, HSPA1B, collagen XIII, collagen XXAI, slug, snail, and zeb1 genes which are related to regulation of cell resistance to cytotoxicity and malignancy, and as expected, resulted in increased resistance of cells to multiple chemotherapeutic drugs including etoposide, doxorubicin, daunorubicin, cisplatin, oxaliplatin and 5-FU. Interestingly, however, acidic environment dramatically sensitized GC cells to apoptosis induced by tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). Consistently, the acidity at pH 6.5 increased mRNA levels of DR4 and DR5 genes, and also elevated protein expression of both death receptors as detected by immunoblotting. Gene silencing analysis showed that of these two receptors, the major role in this effect was played by DR5. Therefore, these results suggest that extracellular acidity can sensitize TRAIL-mediated apoptosis at least partially via DR5 in GCs while it confers resistance to various type of chemotherapeutic drugs.

• 대한의생명과학회지
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• 제2권2호
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• pp.153-158
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• 1996

Verapamil은 항암제에 대한 내성을 극복하기 위하여 실험적으로 사용하는 대표적인 약제로 알려져 있다 본 연구에서는 부인과 종양중 자궁경부암 치료시에 발생하는 항암 화학요법제에 대한 내성을 극복하기 위한 기초적인 실험으로 인체 자궁경부암 유래의 HeLa 및 Caski 세포주를 이용, MTT법으로 verapamil과 5-FU 및 DDP를 단독 혹은 병용 처리하여 세포독성 상승효과를 측정하였다. Verapamil 단독투여시 각 세포주는 용량에 비례하여 세포독성이 증가하였으며, 각 항암제와의 병용 투여시에 세포독성의 상승효과가 관찰이 되었으며, HeLa세포주에서 그 효과가 가장 높았다. 이러한 결과를 바탕으로 세포내 내성발현의 기전의 탐구가 필요하며 자궁경부암 화학요법에 verapamil사용의 이론적인 가능성을 제시하고 있다

• 한국미생물·생명공학회지
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• 제32권1호
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• pp.47-51
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• 2004

암세포가 특정 항암제에 의해 내성을 획득하면 구조가 상이한 타 항암제에도 교차내성을 나타내는 이른바 암세포의 다약제 내성이 암 화학요법에 있어서 가장 심각한 문제가 되고 있다. 본 연구에서는 다약제 내성 암세포주인 CL02 세포를 이용하여 cellulose 용해성 점액세균인 Sorangium cellulosum의 60여종의 균주를 대상으로 다약재 내성 암세포에 유효한 항암물질을 탐색하는 과정에서, 균주 JW1006의 대사산물에서 강한 증식억제 활성을 발견하고 그 활성 본체로서 macrolide계 화합물인 Disorazoles $A_1$과 $A_2$를 분리하였다 Disorazoles $A_1$과 $A_2$는 인체기원의 암세포에 대해 모두 강한 세포독성($IC_{50}$ ＜0.04 ng/$m\ell$)을 나타낼 뿐 아니라 다약제내성 세포주인 CL02와 cisplatin내성 세포주인 CP70에 대해서 감수성 세포주와 동일한 활성을 나타내어 다약제 내성을 극복하는 우수한 활성 물질임을 확인하였다