• Asian Pacific Journal of Cancer Prevention
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• v.14 no.9
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• pp.5361-5365
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• 2013

The objective of this study was to evaluate the influence of a genetic variant in the multidrug resistance 1 gene (MDR1) on hepatocellular carcinoma (HCC) risk. This case-control study was conducted in a Chinese population of 645 HCC cases and 658 cancer-free controls. The genotype of the c.3751G>A genetic variant in the MDR1 gene was investigated by created restriction site-polymerase chain reaction (CRS-PCR) and DNA sequencing methods. Our data demonstrated significantly differences detected in the allelic and genotypic frequencies between HCC cases and those of cancer-free controls. Association analyses indicated that there were statistically increased risk of HCC in the homozygote comparison (AA versus (vs.) GG: OR=2.22, 95% CI 1.51-3.27, ${\chi}^2$=16.90, P<0.001), dominant model (AA/GA vs. GG: OR=1.25, 95% CI 1.00-1.55, ${\chi}^2$=3.98, P=0.046), recessive model (AA vs. GA/GG: OR=2.14, 95% CI 1.47-3.09, ${\chi}^2$=16.68, P<0.001) and allele comparison (A vs. G: OR=1.33, 95% CI 1.13-1.57, ${\chi}^2$=11.66, P=0.001). The allele-A and genotype-AA may contribute to HCC susceptibility. These preliminary findings suggest that the c.3751G>A genetic variant in the MDR1 gene is potentially related to HCC susceptibility in a Chinese Han population, and might be used as a molecular marker for evaluating HCC susceptibility.

• The Korean Journal of Nuclear Medicine
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• v.38 no.2
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• pp.180-189
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• 2004

Although the outcome of cancer patients after cytotoxic chemotherapy is related diverse mechanisms, multidrug resistance (MDR) for chemotherapeutic drugs due to cellular P-glycoprotein (Pgp) or multidrug-resistance associated protein (MRP) is most important factor in the chemotherapy failure to cancer. A large number of pharmacologic compounds, including verapamil, quinidine, tamoxifen, cyclosporin A and quinolone derivatives have been reported to overcome MDR. Single photon emission computed tomography (SPECT) and positron emission tomography (PET) are available for the detection of Pgp and MRP-mediated transporter. $^{99m}Tc$-MIBI and other $^{99m}Tc$-radiopharmaceuticals are substrates for Pgp and MRP, and have been used in clinical studies for tumor imaging, and to visualize blockade of PgP-mediated transport after modulation of Pgp pump. Colchicine, verapamil and daunorubicin labeled with $^{11}C$ have been evaluated for the quantification of Pgp-mediated transport with PET in vivo and reported to be feasible substrates with which to image Pgp function in tumors. Leukotrienes are specific substrates for MRP and $N-[^{11}C]acetyl-leukotriene$ E4 provides an opportunity to study MRP function non-invasively in vivo. SPECT and PET pharmaceuticals have successfully used to evaluate pharmacologic effects of MDR modulators. Imaging of MDR and reversal of MDR with bioluminescence in a living animal is also evaluated for future clinical trial. We have described recent advances in molecular imaging of MDR and reviewed recent publications regarding feasibility of SPECT and PET imaging to study the functionality of MDR transporters in vivo.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.24
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• pp.10597-10601
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• 2015

Up-regulation of multidrug resistance-associated protein 1 (MRP1) is regarded as one of the main causes for multidrug resistance (MDR) of tumor cells, leading to failure of chemotherapy-based treatment for a multitude of cancers. However, whether silencing the overexpressed MRP1 is sufficient to reverse MDR has yet to be validated. This study demonstrated that RNAi-based knockdown of MRP1 reversed the increased efflux ability and MDR efficiently. Two different short haipin RNAs (shRNAs) targeting MRP1 were designed and inserted into pSilence-2.1-neo. The shRNA recombinant plasmids were transfected into cis-dichlorodiamineplatinum-resistant A549 lung (A549/DDP) cells, and then shRNA expressing cell clones were collected and maintained. Real time PCR and immunofluorescence staining for MRP1 revealed a high silent efficiency of these two shRNAs. Functionally, shRNA-expressing cells showed increased rhodamine 123 retention in A549/DDP cells, indicating reduced efflux ability of tumor cells in the absence of MRP1. Consistently, MRP1-silent cells exhibited decreased resistance to 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) and DDP, suggesting reversal of MDR in these tumor cells. Specifically, MRP1 knockdown increased the DDP-induced apoptosis of A549/DDP cells by increased trapping of their cell cycling in the G2 stage. Taken together, this study demonstrated that RNAi-based silencing of MRP1 is sufficient to reverse MDR in tumor cells, shedding light on possible novel clinical treatment of cancers.

• Tuberculosis and Respiratory Diseases
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• v.58 no.2
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• pp.135-141
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• 2005

배경 및 목적 : Multidrug Resistance-1 (MDR1) 유전자는 다약제내성에 관여하는 P-glycoprotein을 암호화한다. MDR1 유전자의 다형성은 P-glycoprotein의 발현과 기능의 차이를 일으켜 항암화학요법 반응에 영향을 미칠 수 있을 것이다. 저자들은 소세포폐암 환자에서 MDR1 유전자의 다형성과 일배체형에 따른 항암화학요법에 대한 반응을 조사하였다. 대상 및 방법 : 경북대학병원에서 병리적으로 소세포폐암으로 진단받고 etoposide-cisplatin 항암화학요법을 받은 54명을 대상으로 하였다. 전혈 5cc에서 DNA를 추출하고 PCR-RFLP법을 통해 MDR1 유전자 엑손 21의 2677G>T 다형성과, 엑손 26의 3435C>T 다형성을 조사하고 다형성과 일배체형에 따른 항암화학요법의 반응을 조사하였다. 결 과 : 2677G>T 유전자형에 따른 항암화학요법의 반응은 유의한 차이가 없었다. 3435 CC 유전자형은 3435 CT+TT 형에 비해 치료 반응율이 유의하게 높았다 (P = 0.025). 유전자형 분석 결과와 일치되게 2677G/3435C 일배체형은 다른 일배체형에 비해 치료반응을 보이는 경우가 유의하게 많았다 (P = 0.015). 결 론 : 소세포폐암에서 MDR1 유전자의 2677G>T와 3435C>T 다형성 및 이들 다형성의 일배체형은 etoposide-cisplatin 항암화학요법의 반응을 예측할 수 있는 지표로 사용될 수 있을 것으로 생각된다.

• YAKHAK HOEJI
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• v.49 no.1
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• pp.38-43
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• 2005

The occurrence of resistance to chemotherapeutic drugs is a major problem for successful cancer treatment. This resistant phenotype of cancer cell frequently reveals a broad spectrum to structurally and/or functionally unrelated anticancer drugs, termed multidrug resistance (MDR). Overexpression of P-glycoprotein (P-gp), a transmembrane drug efflux pump, is a major mechanism of MDR. Accordingly, considerable effort has been directed towards to development of compounds that inhibit P-gp, reverse the MDR phenotype and sensitize cancer cells to conventional chemotherapy without undesired toxicological effects. In an effort to search for novel MDR reversal agent, we tested the cytotoxicity of paclitaxel, a well-known substrate of P-gp, against P-gp-expressing HCT15 and HCT15/CL02 human colorectal cancer cells in the presence or absence of benzotriazepin analogues, as well as against P-gp-negative A549 human non-small cell lung and SK-OV-3 human ovarian cancer cells in vitro. Among the compounds tested, the agents that have phenyl amide moiety at 3 position remarkably increased the cytotoxicity of paclitaxel against P-gp-expressing cancer cells, but not against P-gp-negative cancer cells. BTZ-15 and BTZ-16 at $4\;{\mu}M$ revealed similar MDR reversal activity to $10\;{\mu}M$ verapamil, a well-known MDR reversal agent.

• Korean Journal of Microbiology
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• v.54 no.1
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• pp.53-59
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• 2018

The objective of this study was to investigate the plasmid profiling of multi-drug resistant (MDR) Vibrio in influent (inflow) and effluent (discharged) water samples of fish farms in Jeju, South Korea. MDR isolates identified through disc diffusion susceptibility tests, were subjected to plasmid profiling. One hundred fifty Vibrio isolates were obtained from each influent and effluent water sample. All MDR isolates were subjected to plasmid profiling. Greater number of bacteria were enumerated from effluents (61%) comparing to influents (39%). High incidence of neomycin, sulfamethoxazole, amoxicillin and oxytetracycline resistance was observed among the isolates, which was higher in effluent samples. In contrast, Vibrio isolates were more susceptible to florfenicol, chloramphenicol, ciprofloxacin, and nalidixic acid. Among 99 (influent 39 and effluent 60) MDR isolates, a total of 58 (influent 38 and effluent 20) were found to bear plasmids ranging from 1.7 kb to >10 kb and showed 19 different antibiograms according to the size of plasmids. MDR isolates showed six and four distinct plasmid profiles in influent and effluent, respectively. Effluent samples contained more plasmid-carrying MDR Vibrio isolates with more diverse plasmid profiles and antibiograms, suggesting that fish farm tanks may serve as a reservoir of antibiotic resistance genes. The presence of plasmid-carrying MDR Vibrio isolates in fish farm effluent water may contribute to the dissemination of antibiotic resistance genes to the environments, which ultimately poses threat to human health.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.3
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• pp.1009-1014
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• 2016

It is not clear how gene polymorphisms affecting drugs can contributes totheir efficacy in multiple myeloma (MM). We here aimed to explore associations among gene polymorphisms of tumor necrosis factor alpha (TNFalpha), nitric oxide synthesis 3 (NOS3) and multi-drug resistance 1 (MDR1), clinical parameters, prognosis and survival in MM patients treated with VAD (vincristine-adriamycine-dexamethasone), MP (mephalane-prednisolone), autolougus stem cell transplantation (ASCT), BODEC (bortezomib-dexamethasone-cyclophosphamide) and TD (thalidomide-dexamethasone). We analyzed TNFalpha, NOS 3 and MDR1 in 77 patients with MM and 77 healthy controls. The genotyping was performed with PCR and/or PCR-RFLP. There was no clinically significant difference between MM and control groups when TNFalpha (-238) and (-857) and MDR1 gene polymorphisms were studied. However, the TNFalpha gene polymorphism (-308) GG genotype (p=0.012) and NOS3 (+894) TT genotype (p=0.008) were more common in the MM group compared to healthy controls. NOS3 (VNTR) AA (p=0.007) and NOS3 (+894) GG genotypes (p=0.004) were decreased in the MM group in contrast. In conclusion, the NOS3 (+894) TT and TNFalpha (-308) GG genotypes may have roles in myeloma pathogenesis.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.5
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• pp.2285-2289
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• 2012

Multidrug resistance (MDR) is a main cause of failure in the chemotherapeutic treatment of malignant disorders. One of the well-known genes responsible for drug resistance encodes the multidrug resistance-associated protein (MRP1). The association of MRP1 with clinical drug resistance has not systematically been investigated in Iranian pediatric leukemia patients. We therefore applied real-time RT-PCR technology to study the association between the MRP1 gene and MDR phenotype in Iranian pediatric leukemia patients. We found that overexpression of MRP1 occurred in most Iranian pediatric leukemia patients at relapse. However, no relation between MRP1 mRNA levels and other clinical characteristics, including cytogenetic subgroups and FAB subtypes, was found.

• Tuberculosis and Respiratory Diseases
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• v.61 no.1
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• pp.13-19
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• 2006

Background: Acinetobacter baumannii has emerged as an important nosocomial pathogen worldwide. The incidence of these infections has recently begun to increase. The mortality rate associated with these infections is high (bacteremia; 52%, pneumonia: 23%~73%) and multidrug resistance has been reported. For the effective control of multidrug-resistant Acinetobacter baumannii(MDR-AB), the impact of these organisms in clinical practice should be determined. This study compared the clinical characteristics, mortality and morbidity of Acinetobacter nosocomial pneumonia between MDR strain and non-MDR strain. Methods: From Jan. 1, 2002 to Nov. 1. 2004, 47 adult patients with Acinetobacter nosocomial pneumonia in Chuncheon Sacred Heart Hospital were recruited and analyzed retrospectively. MDR-AB was defined as showing in vitro resistance to all commercially available antibiotics against A. baumannii. Results: There were 47 patients with Acinetobacter nosocomial pneumonia. MDR-AB and non MDR-AB was the cause of the pneumonia in 17 and 30 patients, respectively. Mean age of the former was $69{\pm}11$ years old and the latter was $70{\pm}13$ years old. The mean APCHE II score, ICU days and mortality were not different between the two groups ($16.1{\pm}5.4$ vs. $14.9{\pm}4.8$, P=0.43, $25.1{\pm}13.6$ vs. $39.1{\pm}31.0$, P=0.2, 58.8% vs. 40%, P=0.21). Conclusion: There are no significant differences in mortality and morbidity between MDR and non-MDR Acinetobacter baumannii. The mortality of the two groups is surprisingly high, therefore proper infection control practices are essential.

• Journal of Yeungnam Medical Science
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• v.14 no.1
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• pp.67-76
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• 1997

The occurrence of multidrug resistance (MDR) is one of the main obstacles in the successful chemotherapeutic treatment of cancer. In this study The gene expressions of multidrug resistance-associated protein (MRP), c-myc and c-fos were investigated in L1210 cells. Adriamycin- or vincristine-resistant L1210 cells, L1210AdR or L1210VcR, respectively, has been identified to overexpression of mdr1 gene. The expression leve of MRP gene in L1210AdR and L1210Cis was more decreased than that in L1210 cells. The c-myc and c-fos genes were expressed both in L1210 and resistant sublines. In L1210AdR, the expressions level of c-myc and c-fos genes were decreased than in L1210. However, in L1210VcR and L1210Cis, c-myc and c-fosgene expressionwere rather increased than L1210. These results suggested that MRP does not contribute in resistance of drug-resistant L1210 cells and there is no relations between MRP and mdr1 gene expression. The expression of c-myc and c-fos gene may be changed during transformation of L1210 to drug-resistant sublines.