• BMB Reports
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• 제52권3호
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• pp.208-213
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• 2019

Chemoresistance is the primary obstacle in the treatment of locally advanced and metastatic nasopharyngeal carcinoma (NPC). Recent evidence suggests that the transcription factor forkhead box M1 (FoxM1) is involved in chemoresistance. Our group previously confirmed that FoxM1 is overexpressed in NPC. In this study, we investigated the role of FoxM1 in cisplatin resistance of the cell lines 5-8F and HONE-1 and explored its possible mechanism. Our results showed that FoxM1 and NBS1 were both overexpressed in NPC tissues based on data from the GSE cohort (GSE12452). Then, we measured FoxM1 levels in NPC cells and found FoxM1 was overexpressed in NPC cell lines and could be stimulated by cisplatin. MTT and clonogenic assays, flow cytometry, ${\gamma}H2AX$ immunofluorescence, qRT-PCR, and western blotting revealed that downregulation of FoxM1 sensitized NPC cells to cisplatin and reduced the repair of cisplatin-induced DNA double-strand breaks via inhibition of the MRN (MRE11-RAD50-NBS1)-ATM axis, which might be related to the ability of FoxM1 to regulate NBS1. Subsequently, we demonstrated that enhanced sensitivity of FoxM1 knockdown cells could be reduced by overexpression of NBS1. Taken together, our data demonstrate that downregulation of FoxM1 could improve the sensitivity of NPC cells to cisplatin through inhibition of MRN-ATM-mediated DNA repair, which could be related to FoxM1-dependent regulation of NBS1.

• Asian Pacific Journal of Cancer Prevention
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• 제15권2호
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• pp.917-923
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• 2014

Chondrosarcomas are malignant cartilage-forming tumors of bone which exhibit resistance to both chemotherapy and radiation treatment. miRNAs have been well demonstrated to regulate gene expression and play essential roles in a variety of biological processes, including proliferation, differentiation, migration, cell cycling and apoptosis. In this study, we obtained evidence that miR-100 acts as a tumor suppressor in human chondrosarcomas. Interestingly, cisplatin resistant chondrosarcoma cells exhibit decreased expression of miR-100 compared with parental cells. In addition, we identified mTOR as a direct target of miR-100. Overexpression of miR-100 complementary pairs to the 3' untranslated region (UTR) of mTOR, resulted in sensitization of cisplatin resistant cells to cisplatin. Moreover, recovery of the mTOR pathway by overexpression of S6K desensitized the chondrosarcoma cells to cisplatin, suggesting the miR-100-mediated sensitization to cisplatin dependent on inhibition of mTOR. In summary, the present studies highlight miR-100 as a tumor suppressor in chondrosarcoma contributing to anti-chemoresistance. Overexpression of miR-100 might be exploited as a therapeutic strategy along with cisplatin-based combined chemotherapy for the treatment of clinical chondrosarcoma patients.

• Journal of Microbiology and Biotechnology
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• 제12권5호
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• pp.711-715
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• 2002

Telomerase adds telomeric repeats to chromosomal ends and is known to play an important role in carcinogenesis through cellular immortalization. Since telomerase is an essential pathogenomic factor in malignant tumors, inhibiting telomerase activity is thought to be possible to make telomerase positive tumors more sensitive to cisplatin treatment, which is effective in ovarian cancers, but clinical success Is limited by chemo-resistance. In the present study, cisplatin-sensitive ovarian cancer cell line A2780 and cisplatin-resistant A2780/cp70 cell line were infected with antisense telomerase adenovirus Ad-OA. It was found that the Ad-OA suppressed ovarian cancer cell growth and this effect was mainly due to the induction of caspase-dependent apoptosis. Next, we infected the cisplatin resistant ovarian cancer cell line A2780/ cp70 with Ad-OA and cisplatin concurrently. Interestingly, cisplatin treatment with Ad-Oh was more effective to cisplatin-induced cell death in A2780/cp70 cells compared to cisplatin or the vector group only. These data suggest that cisplatin treatment with Ad-OA may be a new chemo-sensitizer for cisplatin resistant ovarian cancer.

• Asian Pacific Journal of Cancer Prevention
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• 제14권8호
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• pp.4635-4639
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• 2013

Multi-drug resistance (MDR) is an essential aspect of human lung cancer chemotherapy failure. Recent studies have shown that vinorelbine is involved in underlying processes in human tumors, reversing the MDR inseveral types of cancer cells. However, the roles and potential mechanism are not fully clear. In this study, we explored effects of vinorelbine in multi-drug resistance reversal of human lung cancer A549/DDP cells. We found that vinorelbine increased drug sensitivity to cisplatin and intracellular accumulation of rhodamine-123, while decreasing expression of P-glycoprotein (P-gp), multi-drug resistance-associated protein (MRP1) and glutathione-S-transferase ${\pi}$ (GST-${\pi}$) in A549/DDP cells. At the same time, we also established downregulation of p-Akt and decreased transcriptional activation of NF-${\kappa}B$ and twist after vinorelbine treatment. The results indicated that vinorelbine might be used as a potential therapeutic strategy in human lung cancer.

• Tuberculosis and Respiratory Diseases
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• 제62권1호
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• pp.33-42
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• 2007

연구배경: 다양한 고형암에서 HO-1의 높은 발현이 알려져 있고, 그것의 항산화와 항세포고사의 역할로 인해 빠른 암종의 성장에 중요한 역할이 있음이 보고되고 있다. 대표적인 활성산소종 생성 항암제인 Cisplatin은 현재까지 폐암치료에 가장 광범위하게 사용되고 있으나, 여러 내성발생이 임상치료의 주요문제로 대두되고 있다. 저자들은 A549 폐암세포주에서 HO-1의 발현이 증가되었고 HO-1 활성억제제나 siRNA 방법을 통해 생존율의 의미 있는 감소와 세포고사가 유도됨을 보고한 바 있다. 이 연구의 목적은 A549 폐암세포주에 cisplatin 처리시 HO-1의 발현의 증가유무와 기전을 규명하고 실제 HO-1의 억제가 cisplatin에 의한 항암제 감수성을 증가시키는지를 알아보는데 있다. 방 법: 비소세포폐암세포주인 A549, NCI-H23, NCIH157, NCI-H460을 이용하였다. 세포독성은 MTT 방법으로 구하였고, HO-1, Nrf2, MAPK의 발현은 Western blotting으로 확인하였다. 또한 MAPK억제제들을 전처치한 후 cisplatin에 의해 유도된 Nrf2와 HO-1의 발현에 미치는 영향을 역시 Western blotting으로 관찰하였다. A549세포에 활성억제제인 ZnPP나 HO-1 small interfering RNA (siRNA)을 주입하여 cisplatin과의 병합요법시 생존율의 배가효과 유무를 MTT 방법으로 확인하였고, 이러한 효과가 ROS 형성과 HO-1의 발현변화와 관련되는지를 알아보기 위해 $carboxy-H_2DCFDA$ 방법과 Western blotting을 통해 각각 확인하였다. 결 과: Cisplatin 처리시 다른 세포주에 비해 A549 세포가 의의 있게 내성을 보였다. $10{\mu}M$의 농도에서 시간 의존적으로 HO-1, Nrf2, MAPK의 발현이 증가하였고, MAPK 억제제들을 전 처치하였을 때 cisplatin에 의해 유도된 HO-1과 Nrf2의 발현이 억제됨을 확인하였다. HO-1의 활성억제제인 ZnPP와 HO-1 siRNA를 통해 HO-1 mRNA를 직접 억제하는 방법으로 cisplatin과 병합치료시 단독치료에 비해 의의 있는 생존율의 감소를 보였다. 이러한 효과는 활성산소종의 생성 증가와 HO-1의 발현억제에 의한 결과임을 확인하였다. 결 론: Cisplatin 처리시 HO-1의 발현은 MAPKNrf2-HO-1의 경로를 통해 증가하였고, 부분적으로 치료에 대한 내성과 관련이 있었으며, ZnPP 등의 활성억제제나 siRNA를 통한 knock-down 방법으로 HO-1 을 표적으로 억제하는 치료방법을 통해 cisplatin의 항암제 감수성을 증가시켰다.

• Asian Pacific Journal of Cancer Prevention
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• 제13권2호
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• pp.625-631
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• 2012

In order to investigate whether SKI-II could reverse drug resistance and its possible mechanisms, we treated SGC7901/DDP cells with SKI-II or SKI-II in combination with DDP. Then cell growth, apoptosis, micromorphological changes, and expression of SphK1, P-gp, NF-${\kappa}B$, Bcl-2 and Bax were assessed by MTT assay, flow cytometry, electron microscopy, immunocytochemistry and Western blot assay respectively. SGC7901/DDP cells were insensitive to cisplatin 2.5mg/L, but when pretreated with SKI-II, their proliferation was inhibited by cisplatin 2.5mg/L significantly, the inhibition rate increasing with time and dose. The apoptosis rate was also significantly elevated. Expression of SphK1 and P-gp was decreased significantly, Pearson correlation analysis showing significant correlation between the two (r=0.595, P<0.01). Expression of NF-${\kappa}B$ and Bcl-2 was decreased significantly,while that of Bax was increased, compared to the control group. There were significant correlations between SphK1 and NF-${\kappa}B$(r=0.723, P<0.01), NF-${\kappa}B$ and Bcl-2(r=0.768, P<0.01). All these data indicated that SKI-II could reverse drug resistance of SGC7901/DDP to cisplatin by down-regulating expression of P-gp and up-regulating apoptosis through down-regulation of SphK1. The increased apoptotic sensitivity of SGC7901/DDP to cisplatin was due to the decreasing proportion of Bcl-2/Bax via down-regulating NF-${\kappa}B$.

• Journal of Chest Surgery
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• 제34권5호
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• pp.377-385
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• 2001

배경: Cisplain과 같은 세포돗성 약제에 대한 내성은 폐암 치료 실패의 중요한 원인이다. 이러한 항암제에 대한 내성의 발생기전은 복잡하고 아직 완전히 알려져 있지 않지만 불량한 예후의 원인으로 생각된다. 특히 약제 내성이 발생한 환자의 경우 기존의 종양의 급속한 성장뿐 아니라 새로운 전이 병소가 급속히 발생 및 진단됨은 약제 내성을 가진 종양이 전이에의 용이성을 획득하는게 아닌가 의심케한다. 이를 규명하기 위해 Cisplatin에 내성을 지닌 비소세포폐암 세포주 H460/CISm이 전이 능력을 Cisplatin에 민감한 비소세포폐암 세로주 H460과 비교하고자 한다. 대상 및 방법: 약제 내성 세포주를 확보하기 위하여 H460세포에 cisplatin을 점차적으로 증가시켜 처리한 후 배양하였다. H460 세포와 H460/CIS 세로에서의 혈관신생인자와 성장관련인 자의 발현양상, gelatin zymography 분석 그리고 in vivo 실험으로 nude 마우스에서의 자발적 전이 능력의 차이를 비교하였다. 결과: H460 세포를 이식한 마우스에 폐에서는 종양이 형성되지 않았으나 H460/CIS세포를 이식한 마우스 10마리중 8마리에서 종양이 형성되었다. 또한 H460/CIS 세포주에서 전이 관련 유전자로 알려진 angiopoietin-1, vascular endothelial growth factor, basic fibroblast growth factor, matrix metalloproteinase 2 등이 더 발현되었고, 전이의 침습성을 유발하는 gelatinase의 활성이 증가된 것을 확인할 수 있었다. 결론: 본 여구 결과를 통해 cisplatin에 내성을 가진 비소세포폐암세포에서 전이 능력이 증가될 수 있다고 여겨지며 이러한 사실을 토대로 초기 비소세포폐암 환자의 수술 전 항암약물요법의 타당성에 대해서 이야기 하기 위해서는 많은 임상적 연구가 필요하리라 생각된다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권1호
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• pp.237-242
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• 2013

Cervical cancer is the second most common cause of cancer in women and has a high mortality rate. Cisplatin, an antitumor agent, is generally used for its treatment. However, the administration of cisplatin is associated with side effects and intrinsic resistance. Morinda citrifolia (Noni), a natural plant product, has been shown to have anti-cancer properties. In this study, we used Noni, cisplatin, and the two in combination to study their cytotoxic and apoptosis-inducing effects in cervical cancer HeLa and SiHa cell lines. We demonstrate here, that Noni/Cisplatin by themselves and their combination were able to induce apoptosis in both these cell lines. Cisplatin showed slightly higher cell killing as compared to Noni and their combination showed additive effects. The observed apoptosis appeared to be mediated particularly through the up-regulation of p53 and pro-apoptotic Bax proteins, as well as down-regulation of the anti-apoptotic Bcl-2, Bcl-$X_L$ proteins and survivin. Augmentation in the activity of caspase-9 and -3 was also observed, suggesting the involvement of the intrinsic mitochondrial pathway of apoptosis for both Noni and Cisplatin in HeLa and SiHa cell lines.

• Journal of Yeungnam Medical Science
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• 제9권1호
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• pp.75-89
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• 1992

복합약제내성암세포주의 출현은 암의 화학 요법에 있어서 중요한 문제점중의 하나이며 이 복합내성 암세포의 출현에 대한 정확한 기전은 아직 밝혀져 있지 않다. 본 실험에서는 약제내성 암세포의 다른 항암제에 대한 복합내성 형성정도와 calcium 길항제인 verapamil에 의한 내성극복 정도를 비교하고 내성 암세포의 세포막 단백질의 변화를 관찰하였다. 사람의 위암 세포주 SNU-1을 cisplatin 농도 $0.001{\mu}M$에서 시작하여 $10{\mu}M$까지 증가시켜 내성세포 SNU-1/$Cis_5$를 얻었으며, MTT assay로 세포성장을 관찰한 결과 doubling time은 SNU-1이 약 29 시간, SNU-1/$Cis_5$는 약 38시간으로 내성세포가 감수성세포보다 성장속도가 느린 것을 관찰하였다. 약제 감수성 검사를 위해서 4일간의 MTT assay로 대조군에 대한 50% 세포 생존시의 약제농도 $IC_{50}$를 비교하여 상대적 내성도 (Relative Resistance, RR)를 측정하였는데 cisplatin, 81.4; vinblastine, > 43.0; epirubicin, 22.9 ; dactinomycin, 16.0 ; etoposide, 15.0 ; vincristine, 9.2 ; adriamycin, 5.7 ; aclarubicin, 5.3으로 관찰되었고 그외의 약제인 cyclophosphamide, 5-fluorouracil, methotrexate, daunorubicin에서는 낮게 나타났다. $10{\mu}M$의 verapamil에 의한 내성 억제 효과는 vincristine, 13.1 ; epirubicin, 10.0 ; etoposide, 6.3 ; vinblastine, 4.4 ; dactinomycin, 3.6 ; daunorubicin, 2.4로 나타났다. Radioiodination을 이용한 SDS-PAGE로 SNU-1/$Cis_5$에서 항암제 내성과 관련된 것으로 여겨지는 51,400와 81,300 dalton의 막단백질의 발현을 관찰하였다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권23호
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• pp.10439-10444
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• 2015

Many chemotherapeutic agents have been successfully used to treat hepatocellular carcinoma (HCC); however, the development of chemoresistance in liver cancer cells usually results in a relapse and worsening of prognosis. It has been demonstrated that DNA methylation and histone modification play crucial roles in chemotherapy resistance. Currently, extensive research has shown that there is another potential mechanism of gene expression control, which is mediated through the function of short noncoding RNAs, especially for microRNAs (miRNAs), but little is known about their roles in cancer cell drug resistance. In present study, by taking advantage of miRNA effects on the resistance of human hepatocellular carcinoma cells line to cisplatin, it has been demonstrated that miR-340 were significantly downregulated whereas Nrf2 was upregulated in HepG2/CDDP (cisplatin) cells, compared with parental HepG2 cells. Bioinformatics analysis and luciferase assays of Nrf2-3'-untranslated region-based reporter constructor indicated that Nrf2 was the direct target gene of miR-340, miR-340 mimics suppressing Nrf2-dependent antioxidant pathway and enhancing the sensitivity of HepG2/CDDP cells to cisplatin. Interestingly, transfection with miR-340 mimics combined with miR-340 inhibitors reactivated the Nrf2 related pathway and restored the resistance of HepG2/CDDP cells to CDDP. Collectively, the results first suggested that lower expression of miR-340 is involved in the development of CDDP resistance in hepatocellular carcinoma cell line, at least partly due to regulating Nrf2-dependent antioxidant pathway.