• Asian Pacific Journal of Cancer Prevention
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• 제13권5호
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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.

• Journal of Yeungnam Medical Science
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• 제14권1호
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• pp.67-76
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• 1997

항암제에 대한 내성은 내인성 또는 획득한 내성 모두가 암의 치료에 장애가 된다. P-당단백질을 encode하고있는 mdr1 유전자의 발현이 항암제에 대해 내성을 가지고 있는 암세포에서 많이 관찰되고 있으며, 최근에는 시험관적으로 항암제에 대한 내성이 유도된 암세포주들에서 mdr1 유전자가 발현되지 않는 암세포들이 보고되고 있다. 다제내성에 관계하는 또 하나의 유전자인 MRP 발현정도를 L1210세포와 내성인 L1210변이주들에서 조사하였으며, c-myc과 c-fos 유전자의 발현변화를 관찰하였다. RT-PCR을 시행하여 L1210, L1210AdR, L1210VcR에서 MRP 유전자발현을 확인하였으며, Northern hybridization한 결과 L1210세포에 비하여 L1210AdR은 유전자 발현이 40% 정도 감소하였으며, L12l0Cis는 90% 정도의 유전자 발현감소가 관찰되었다. c-myc과 c-fos유전자의 Northern hybridization한 결과 L1210에 비하여 L1210AdR은 발현감소가 나타났으나, L1210VcR과 L1210Cis의 경우는 오히려 발현증가가 관찰되었다.

• 미생물학회지
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• 제49권2호
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• pp.126-130
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• 2013

원유시료에서 분리한 장알균속 세균 245균주의 항생제 내성에 관여하는 다중약물 유출 펌프 유전자 분포도와 항생제 내성 패턴을 연구하였다. 그 결과 245 장알균속 균주의 ampicillin에 대한 내성률은 44.1%, erythromycin에 대한 내성률은 79.2%, tetracycline에 대한 내성률은 76.3%, chloramphenicol에 대한 내성률은 36.3%였으며 vancomycin과 ciprofloxacin에 대해서는 모두 감수성임을 알 수 있었다. 내성 관련 유전자 중 MFS타입의 eme(A)는 82.1%의 장알균에 분포하였으며, ABC 타입의 유전자인 efr(A)는 72.7%, efr(B)는 77.1%, lsa는 71.8%의 장알균에 분포하였다. 특히 이러한 유전자의 기원 세균인 Enterococcus faecalis의 경우 eme(A)는 92.5%, efr(A)는 87.4%, efr(B)는 88.4%, lsa는 88.4%의 분포도를 나타내었다. 한편 동일한 장알균속이지만 종이 다른 장알균에서 eme(A)는 E. faecium 4균주, E. avium 7균주, E. durans 4균주 및 E. raffinosus 2균주에 분포하고 있었다. efr(A)는 E. faecium 2균주와 E. durans 2균주에 분포하였으며, efr(B)는 E. faecium 4균주, E. avium 5균주 및 E. durans 4균주에 분포하였다. 본 연구는 우리나라 원유시료에서 분리한 장알균속의 여러 종의 세균에서 동일한 다중약물 유출 펌프(multidrug efflux pump)의 분포에 대한 첫 번째 보고라 사료되며 E. faecalis 이외의 장알균속에서 이러한 유전자의 분포는 서로 다른 종간의 유전자의 수평적인 이동의 가능성을 시사한다.

• Journal of Microbiology
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• 제45권3호
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• pp.272-274
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• 2007

During May to July 2004, three strains of Providencia spp. with multidrug-resistance (MDR) were isolated from urinary specimen of three patients hospitalized with a same hospital room. By PCR analysis, all three strains have been found to carry both VIM-2 type $metallo-{\beta}-lactamase$ gene and PER-1 type extended spectrum ${\beta}-lactamase$ gene. One out of three strains carried additional resistance gene, armA, 16S rRNA methylase gene responsible for high level resistance to aminoglycosides. To our knowledge, this is the first report on the identification of Providencia spp. simultaneously carrying $bla_{VIM-2},\;bla_{PER-1}$, and armA genes.

• Journal of Veterinary Science
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• 제24권6호
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• pp.82.1-82.12
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• 2023

Background: The current conventional serotyping based on antigen-antisera agglutination could not provide a better understanding of the potential pathogenicity of Salmonella enterica subsp. enterica serovar Brancaster. Surveillance data from Malaysian poultry farms indicated an increase in its presence over the years. Objective: This study aims to investigate the virulence determinants and antimicrobial resistance in S. Brancaster isolated from chickens in Malaysia. Methods: One hundred strains of archived S. Brancaster isolated from chicken cloacal swabs and raw chicken meat from 2017 to 2022 were studied. Two sets of multiplex polymerase chain reaction (PCR) were conducted to identify eight virulence genes associated with pathogenicity in Salmonella (invasion protein gene [invA], Salmonella invasion protein gene [sipB], Salmonella-induced filament gene [sifA], cytolethal-distending toxin B gene [cdtB], Salmonella iron transporter gene [sitC], Salmonella pathogenicity islands gene [spiA], Salmonella plasmid virulence gene [spvB], and inositol phosphate phosphatase gene [sopB]). Antimicrobial susceptibility assessment was conducted by disc diffusion method on nine selected antibiotics for the S. Brancaster isolates. S. Brancaster, with the phenotypic ACSSuT-resistance pattern (ampicillin, chloramphenicol, streptomycin, sulphonamides, and tetracycline), was subjected to PCR to detect the corresponding resistance gene(s). Results: Virulence genes detected in S. Brancaster in this study were invA, sitC, spiA, sipB, sopB, sifA, cdtB, and spvB. A total of 36 antibiogram patterns of S. Brancaster with a high level of multidrug resistance were observed, with ampicillin exhibiting the highest resistance. Over a third of the isolates displayed ACSSuT-resistance, and seven resistance genes (β-lactamase temoneira [bla_TEM], florfenicol/chloramphenicol resistance gene [floR], streptomycin resistance gene [strA], aminoglycoside nucleotidyltransferase gene [ant(3")-Ia], sulfonamides resistance gene [sul-1, sul-2], and tetracycline resistance gene [tetA]) were detected. Conclusion: Multidrug-resistant S. Brancaster from chickens harbored an array of virulence-associated genes similar to other clinically significant and invasive non-typhoidal Salmonella serovars, placing it as another significant foodborne zoonosis.

• 대한골관절종양학회지
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• 제3권1호
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• pp.9-17
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• 1997

Resistance to combination chemotherapy remains challenge in the treatment of osteosarcoma. One of the mechanisms of multiple drug resistance is an increased expression of the multidrug resistance gene(mdr1). Expression of the P-glycoprotein(mdr-1 gene product) was studied immunohistochemically and the mdr-1 gene by in situ hybridization in 33 osteosarcomas relating to various prognostic factors. Thirty cases out of 33 osteosarcomas(90.9%) showed positive cytoplasmic reactions with P-glycoprotein and nineteen instances(57.6%) were strong positive(2+). The older(>20 years) and female patients revealed more intense immunohistochemical reactions rather than those of the younger and male patients. Osteoblastic and chondroblastic osteosarcomas revealed more strong immunohistochemical reactions compared to fibroblastic types. There were no significant staining differences between the type of bony involvement, Broder's grade and the presence of necrosis. On follow-up, the mean survival rate was decreased in the strong positive group, however, this was not statistically significant. In situ hybridization for mdr-1 gene revealed positive signals in 22 cases out of 29 osteosarcomas(75.9%). Chemotherapy was done in 15 cases out of 28 patients(53.6%). The results of immunohistochemistry and in situ hybridization were not correlated with the protocols for chemotherapy. However, this result should be confirmed by a larger scale study about mdr1 mRNA expression.

• 한국미생물·생명공학회지
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• 제31권3호
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• pp.230-234
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• 2003

Small multidrug resistance(SMR) family(TC #2.A.7.1)에 속하는 막단백질 중 하나를 coding하는 Bacillus subtilis의 yvaE유전자의 발현을 유도한 결과, 발현된 YvaE단백질에 의해 대장균세포내에서 살균제를 포함한 다양한 양이온 약제에 대한 efflux활성을 촉매하는 것으로 확인되었다. 같은 operon내에 인접한 yaD유전자의 동시발현을 유도한 결과, 이러한 efflux활성은 억제가 되는 것으로 나타났다. Ethidium bromide를 기질로 하여 fluorimeter를 이용한 efflux transport실험결과, YvaE 단백질이 발현된 대장균세포의 경우 vector만을 함유한 대조세포에 비해 현저히 빠른 efflux활성을 보여주었다 따라서 YvaE 막단백질은 multidrug export를 촉매하는 SMR-type efflux pump임을 확인하였다.

• Archives of Pharmacal Research
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• 제21권3호
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• pp.344-347
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• 1998

To overcome multidrug resistance (MDR) in cancer chemotherapy, we prepared various plant extracts and searched for a component which is effective for inhibition of MDR. MDR inhibition activity was determined by measuring cytotoxicity to MDR cells using multidrug resistant human fibrocarcinoma KB V20C, which is resistant to 20 nM vincristine and expresses high level of mdr1 gene. Of various plant extracts, the MeOH extract of the root of Aconitum pseudo-laeve var. erectum was found to have potent inhibitory activity on MDR. The bioassayguided fractionation of the MeOH extract of the plant led to the isolation of an alkaloid, lycaconitine, as an active principle. And the $IC_{50}$ of lycaconitne for KB V20C cells was $74\mu{g}$/ml.

• Archives of Pharmacal Research
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• 제19권3호
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• pp.213-218
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• 1996

Multidrug resistance (MDR) has been a major problem in cancer chemotherapy. To overcome this problem, we prepared minor ginsenosides stereoselectively from ginseng saponins and searched for a ginseng component which is effective for inhibition of MDR. MDR inhibition activity was determined by measuring cytotoxicity to MDR cells using multidrug resistant human fibrocarcinoma KB V20C, which is resistant to 20 nM vincristine and expresses high level of mdr1 gene. Of several ginseng components, 20(S)-ginsenoside Rg_3$, a red ginseng saponin, was found to have the most potent inhibitory activity on MDR and it's concentration capable of inhibiting 50% growth was $82\muM$.

• Asian Pacific Journal of Cancer Prevention
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• 제16권18호
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• pp.8467-8471
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• 2016

Background: One of the major mechanisms for drug resistance is associated with altered anticancer drug transport, mediated by the human-adenosine triphosphate binding cassette (ABC) transporter superfamily proteins. The overexpression of adenosine triphosphate binding cassette, sub-family B, member 1 (ABCB1) by multidrug-resistant cancer cells is a serious impediment to chemotherapy. In our study we have studied the possibility that structural single-nucleotide polymorphisms (SNP) are the mechanism of ABCB1 overexpression. Materials and Methods: A total of 101 gastric cancer multidrug resistant cases and 100 controls were genotyped with sequence-specific primed PCR (SSP-PCR). Gene expression was evaluated for 70 multidrug resistant cases and 54 controls by real time PCR. The correlation between the two groups was based on secondary structures of RNA predicted by bioinformatics tool. Results: The results of genotyping showed that among 3 studied SNPs, rs28381943 and rs2032586 had significant differences between patient and control groups but there were no differences in the two groups for C3435T. The results of real time PCR showed over-expression of ABCB1 when we compared our data with each of the genotypes in average mode. Prediction of secondary structures in the existence of 2 related SNPs (rs28381943 and rs2032586) showed that the amount of ${\Delta}G$ for original mRNA is higher than the amount of ${\Delta}G$ for the two mentioned SNPs. Conclusions: We have observed that 2 of our studied SNPs (rs283821943 and rs2032586) may elevate the expression of ABCB1 gene, through increase in mRNA stability, while this was not the case for C3435T.