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Sample records for abcb1 mdr1 expression

  1. A synonymous polymorphism in a common MDR1 (ABCB1) haplotype shapes protein function

    OpenAIRE

    Fung, King Leung; Gottesman, Michael M.

    2009-01-01

    The MDR1 (ABCB1) gene encodes a membrane-bound transporter that actively effluxes a wide range of compounds from cells. The overexpression of MDR1 by multidrug-resistant cancer cells is a serious impediment to chemotherapy. MDR1 is expressed in various tissues to protect them from the adverse effect of toxins. The pharmacokinetics of drugs that are also MDR1 substrates also influence disease outcome and treatment efficacy. Although MDR1 is a well conserved gene, there is increasing evidence t...

  2. Expression of multidrug resistance markers ABCB1 (MDR-1/P-gp) and ABCC1 (MRP-1) in renal cell carcinoma.

    LENUS (Irish Health Repository)

    Walsh, Naomi

    2009-01-01

    BACKGROUND: Renal cell carcinoma patients respond poorly to conventional chemotherapy, this unresponsiveness may be attributable to multidrug resistance (MDR). The mechanisms of MDR in renal cancer are not fully understood and the specific contribution of ABC transporter proteins which have been implicated in the chemoresistance of various cancers has not been fully defined in this disease. METHODS: In this retrospective study the expression of two of these transporter efflux pumps, namely MDR-1 P-gp (ABCB1) and MRP-1 (ABCC1) were studied by immunohistochemistry in archival material from 95 renal cell carcinoma patients. RESULTS: In the first study investigating MDR-1 P-gp and MRP-1 protein expression patterns in renal cell carcinoma patients, high levels of expression of both efflux pumps are observed with 100% of tumours studied showing MDR-1 P-gp and MRP-1 positivity. CONCLUSION: Although these findings do not prove a causal role, the high frequency of tumours expressing these efflux pumps suggests that they may be important contributors to the chemoresistance of this tumour type.

  3. Beta-Amyloid Downregulates MDR1-P-Glycoprotein (Abcb1 Expression at the Blood-Brain Barrier in Mice

    Directory of Open Access Journals (Sweden)

    Anja Brenn

    2011-01-01

    Full Text Available Neurovascular dysfunction is an important component of Alzheimer's disease, leading to reduced clearance across the blood-brain barrier and accumulation of neurotoxic β-amyloid (Aβ peptides in the brain. It has been shown that the ABC transport protein P-glycoprotein (P-gp, ABCB1 is involved in the export of Aβ from the brain into the blood. To determine whether Aβ influences the expression of key Aβ transporters, we studied the effects of 1-day subcutaneous Aβ1-40 and Aβ1-42 administration via Alzet mini-osmotic pumps on P-gp, BCRP, LRP1, and RAGE expression in the brain of 90-day-old male FVB mice. Our results demonstrate significantly reduced P-gp, LRP1, and RAGE mRNA expression in mice treated with Aβ1-42 compared to controls, while BCRP expression was not affected. The expression of the four proteins was unchanged in mice treated with Aβ1-40 or reverse-sequence peptides. These findings indicate that, in addition to the age-related decrease of P-gp expression, Aβ1-42 itself downregulates the expression of P-gp and other Aβ-transporters, which could exacerbate the intracerebral accumulation of Aβ and thereby accelerate neurodegeneration in Alzheimer's disease and cerebral β-amyloid angiopathy.

  4. IPEC-J2 MDR1, a Novel High-Resistance Cell Line with Functional Expression of Human P-glycoprotein (ABCB1) for Drug Screening Studies

    DEFF Research Database (Denmark)

    Saaby, Lasse; Helms, Hans Christian Cederberg; Brodin, Birger

    2016-01-01

    The P-glycoprotein (P-gp) efflux pump has been shown to affect drug distribution and absorption in various organs and to cause drug resistance in cancer therapy. The aim of this work was to develop a cell line to serve as a screening system for potential substrates of P-gp. This requires a cell...... line with high paracellular tightness, low expression of nonhuman ABC transporters, and high expression of functional human P-gp (ABCB1). The porcine intestinal epithelial cell line, IPEC-J2, was selected as a transfection host, due to its ability to form extremely high-resistance monolayers (>10,000 Ω......·cm(2)) and its low endogenous expression of ABC-type efflux transporters. The IPEC-J2 cells were transfected with a plasmid that contained the sequence of the human MDR1 gene, which encodes P-gp, followed by a selection of successfully transfected cells with geneticin and puromycin. The resulting cell...

  5. ABCB1 (MDR1) polymorphisms and ovarian cancer progression and survival

    DEFF Research Database (Denmark)

    Johnatty, Sharon E; Beesley, Jonathan; Gao, Bo;

    2013-01-01

    ABCB1 encodes the multi-drug efflux pump P-glycoprotein (P-gp) and has been implicated in multi-drug resistance. We comprehensively evaluated this gene and flanking regions for an association with clinical outcome in epithelial ovarian cancer (EOC)....

  6. Rapid genotyping assays for the 4-base pair deletion of canine MDR1/ABCB1 gene and low frequency of the mutant allele in Border Collie dogs.

    Science.gov (United States)

    Mizukami, Keijiro; Chang, Hye-Sook; Yabuki, Akira; Kawamichi, Takuji; Hossain, Mohammad A; Rahman, Mohammad M; Uddin, Mohammad M; Yamato, Osamu

    2012-01-01

    P-glycoprotein, encoded by the MDR1 or ABCB1 gene, is an integral component of the blood-brain barrier as an efflux pump for xenobiotics crucial in limiting drug uptake into the central nervous system. Dogs homozygous for a 4-base pair deletion of the canine MDR1 gene show altered expression or function of P-glycoprotein, resulting in neurotoxicosis after administration of the substrate drugs. In the present study, the usefulness of microchip electrophoresis for genotyping assays detecting this deletion mutation was evaluated. Mutagenically separated polymerase chain reaction (MS-PCR) and real-time PCR assays were newly developed and evaluated. Furthermore, a genotyping survey was carried out in a population of Border Collies dogs in Japan to determine the allele frequency in this breed. Microchip electrophoresis showed advantages in detection sensitivity and time saving over other modes of electrophoresis. The MS-PCR assay clearly discriminated all genotypes. Real-time PCR assay was most suitable for a large-scale survey due to its high throughput and rapidity. The genotyping survey demonstrated that the carrier and mutant allele frequencies were 0.49% and 0.25%, respectively, suggesting that the mutant allele frequency in Border Collies is markedly low compared to that in the susceptible dog breeds such as rough and smooth Collies. PMID:22362942

  7. Analysis of genotype and haplotype effects of ABCB1 (MDR1) polymorphisms in the risk of medically refractory epilepsy in an Indian population.

    Science.gov (United States)

    Vahab, Saadi Abdul; Sen, Supratim; Ravindran, Nivedita; Mony, Sridevi; Mathew, Anila; Vijayan, Neetha; Nayak, Geetha; Bhaskaranand, Nalini; Banerjee, Moinak; Satyamoorthy, Kapaettu

    2009-01-01

    The transmembrane P-glycoprotein that functions as a drug-efflux transporter coded by ATP-binding cassette, subfamily B, member 1/Multidrug Resistance 1 (ABCB1/MDR1) gene is considered relevant to drug absorption and elimination, with access to the central nervous system. Effects of three ABCB1 single nucleotide polymorphisms (SNPs) in genotypic and haplotypic combination have been evaluated in a south Indian population for risk of pediatric medically refractory epilepsy. The study included age and sex matched medically refractory (N=113) cases and drug responsive epilepsy patients (N=129) as controls, belonging to the same ethnic population recruited from a tertiary referral centre, of Karnataka, Southern India. The genotype frequencies of SNPs c.1236C>T, c.2677G>T/A, and c.3435C>T were determined from genomic DNA of the cases and controls by PCR- RFLP and confirmatory DNA sequencing. 256 normal population samples of the same ethnicity were genotyped for the three loci to check for population stratification. Results indicate that there was no statistically significant difference between allele and genotype frequencies of refractory and drug responsive epilepsy patients. The predicted haplotype frequencies of the three polymorphisms did not show significant difference between cases and controls. The results confirm earlier observations on absence of association of ABCB1 polymorphisms with medically refractory epilepsy. PMID:19571437

  8. Impact of Genetic Polymorphisms of ABCB1 (MDR1, P-Glycoprotein) on Drug Disposition and Potential Clinical Implications: Update of the Literature.

    Science.gov (United States)

    Wolking, Stefan; Schaeffeler, Elke; Lerche, Holger; Schwab, Matthias; Nies, Anne T

    2015-07-01

    ATP-binding cassette transporter B1 (ABCB1; P-glycoprotein; multidrug resistance protein 1) is an adenosine triphosphate (ATP)-dependent efflux transporter located in the plasma membrane of many different cell types. Numerous structurally unrelated compounds, including drugs and environmental toxins, have been identified as substrates. ABCB1 limits the absorption of xenobiotics from the gut lumen, protects sensitive tissues (e.g. the brain, fetus and testes) from xenobiotics and is involved in biliary and renal secretion of its substrates. In recent years, a large number of polymorphisms of the ABCB1 [ATP-binding cassette, sub-family B (MDR/TAP), member 1] gene have been described. The variants 1236C>T (rs1128503, p.G412G), 2677G>T/A (rs2032582, p.A893S/T) and 3435C>T (rs1045642, p.I1145I) occur at high allele frequencies and create a common haplotype; therefore, they have been most widely studied. This review provides an overview of clinical studies published between 2002 and March 2015. In summary, the effect of ABCB1 variation on P-glycoprotein expression (messenger RNA and protein expression) and/or activity in various tissues (e.g. the liver, gut and heart) appears to be small. Although polymorphisms and haplotypes of ABCB1 have been associated with alterations in drug disposition and drug response, including adverse events with various ABCB1 substrates in different ethnic populations, the results have been majorly conflicting, with limited clinical relevance. Future research activities are warranted, considering a deep-sequencing approach, as well as well-designed clinical studies with appropriate sample sizes to elucidate the impact of rare ABCB1 variants and their potential consequences for effect sizes.

  9. MDR1 gene expression in primary colorectal carcinomas.

    OpenAIRE

    Pirker, R; Wallner, J.; Gsur, A; Götzl, M.; Zöchbauer, S; Scheithauer, W.; Depisch, D

    1993-01-01

    The expression of the MDR1 gene, a multidrug resistance gene, was prospectively determined in 113 primary colorectal carcinoma specimens and correlated with clinical data including survival durations of the patients. MDR1 RNA was detected in 65% of the carcinomas. No expression of the MDR2 gene was seen, MDR1 gene expression was independent of age and sex of the patients, size and histologic grading of the tumour, lymph node involvement and distant metastasis. Kaplan-Meier analysis revealed t...

  10. Functional expression of mouse mdr1 in Escherichia coli.

    OpenAIRE

    Bibi, E; Gros, P.; Kaback, H R

    1993-01-01

    We describe functional expression of the mouse multidrug-resistance protein (P-glycoprotein; P-gp) in an Escherichia coli mutant defective in the outer membrane protease ompT. Heterologously expressed mdr1 appears as an unglycosylated species with an apparent molecular mass of 140 kDa in the membrane of the mutant. Unglycosylated mdr1 retains the ability to bind the photoactivatable drug analog [125I]iodoarylazidoprazosin and confers resistance to tetraphenylphosphonium (TPP+) and tetraphenyl...

  11. High frequency of a single nucleotide substitution (c.-6-180T>G) of the canine MDR1/ABCB1 gene associated with phenobarbital-resistant idiopathic epilepsy in Border Collie dogs.

    Science.gov (United States)

    Mizukami, Keijiro; Yabuki, Akira; Chang, Hye-Sook; Uddin, Mohammad Mejbah; Rahman, Mohammad Mahbubur; Kushida, Kazuya; Kohyama, Moeko; Yamato, Osamu

    2013-01-01

    A single nucleotide substitution (c.-6-180T>G) associated with resistance to phenobarbital therapy has been found in the canine MDR1/ABCB1 gene in Border Collies with idiopathic epilepsy. In the present study, a PCR-restriction fragment length polymorphism assay was developed for genotyping this mutation, and a genotyping survey was carried out in a population of 472 Border Collies in Japan to determine the current allele frequency. The survey demonstrated the frequencies of the T/T wild type, T/G heterozygote, and G/G mutant homozygote to be 60.0%, 30.3%, and 9.8%, respectively, indicating that the frequency of the mutant G allele is extremely high (24.9%) in Border Collies. The results suggest that this high mutation frequency of the mutation is likely to cause a high prevalence of phenobarbital-resistant epilepsy in Border Collies. PMID:24302812

  12. High Frequency of a Single Nucleotide Substitution (c.-6-180T>G of the Canine MDR1/ABCB1 Gene Associated with Phenobarbital-Resistant Idiopathic Epilepsy in Border Collie Dogs

    Directory of Open Access Journals (Sweden)

    Keijiro Mizukami

    2013-01-01

    Full Text Available A single nucleotide substitution (c.-6-180T>G associated with resistance to phenobarbital therapy has been found in the canine MDR1/ABCB1 gene in Border Collies with idiopathic epilepsy. In the present study, a PCR-restriction fragment length polymorphism assay was developed for genotyping this mutation, and a genotyping survey was carried out in a population of 472 Border Collies in Japan to determine the current allele frequency. The survey demonstrated the frequencies of the T/T wild type, T/G heterozygote, and G/G mutant homozygote to be 60.0%, 30.3%, and 9.8%, respectively, indicating that the frequency of the mutant G allele is extremely high (24.9% in Border Collies. The results suggest that this high mutation frequency of the mutation is likely to cause a high prevalence of phenobarbital-resistant epilepsy in Border Collies.

  13. Quantitative analysis of MDR1 (multidrug resistance) gene expression in human tumors by polymerase chain reaction

    Energy Technology Data Exchange (ETDEWEB)

    Noonan, K.E.; Beck, C.; Holzmayer, T.A.; Chin, J.E.; Roninson, I.B. (Univ. of Illinois, Chicago (USA)); Wunder, J.S.; Andrulis, I.L. (Mount Sinai Hospital, Toronto, Ontario (Canada)); Gazdar, A.F. (National Cancer Inst., Bethesda, MD (USA)); Willman, C.L.; Griffith, B. (Univ. of New Mexico, Albuquerque (USA)); Von Hoff, D.D. (Univ. of Texas, San Antonio (USA))

    1990-09-01

    The resistance of tumor cells ot chemotheraprutic drugs is a major obstacle to successful cancer chemotherapy. In human cells, expression of the MDR1 gene, encoding a transmembrane efflux pump (P-glycoprotein), leads to decreased intracellular accumulation and resistance to a variety of lipophilic drugs (multidrug resistance; MDR). The levels of MDR in cell lines selected in bitro have been shown to correlate with the steady-state levels of MDR1 mRNA and P-glycoprotein. In cells with a severalfold increase in cellular drug resistance, MDR1 expression levels are close to the limits of detection by conventional assays. MDR1 expression has been frequently observed in human tumors after chemotherapy and in some but not all types of clinically refactory tumors untreated with chemotherapeutic drugs. The authors have devised a highly sensitive, specific, and quantitative protocol for measuring the levels of MDR1 mRNA in clincal samples, based on the polymerase chain reaction. They have used this assay to measure MDR1 gene expression in MDR cell lines and >300 normal tissues, tumor-derived cell lines, and clinical specimens of untreated tumors of the types in which MDR1 expression was rarely observed by standard assays. Low levels of MDR1 expression were found by polymerase chain reaction in most solid tumors and leukemias tested. The frequency of samples without detectable MDR1 expression varied among different types of tumors; MDR1-negative samples were ost common among tumor types known to be relatively responsive to chemotherapy.

  14. Detection of MDR1 mRNA expression with optimized gold nanoparticle beacon

    Science.gov (United States)

    Zhou, Qiumei; Qian, Zhiyu; Gu, Yueqing

    2016-03-01

    MDR1 (multidrug resistance gene) mRNA expression is a promising biomarker for the prediction of doxorubicin resistance in clinic. However, the traditional technical process in clinic is complicated and cannot perform the real-time detection mRNA in living single cells. In this study, the expression of MDR1 mRNA was analyzed based on optimized gold nanoparticle beacon in tumor cells. Firstly, gold nanoparticle (AuNP) was modified by thiol-PEG, and the MDR1 beacon sequence was screened and optimized using a BLAST bioinformatics strategy. Then, optimized MDR1 molecular beacons were characterized by transmission electron microscope, UV-vis and fluorescence spectroscopies. The cytotoxicity of MDR1 molecular beacon on L-02, K562 and K562/Adr cells were investigated by MTT assay, suggesting that MDR1 molecular beacon was low inherent cytotoxicity. Dark field microscope was used to investigate the cellular uptake of hDAuNP beacon assisted with ultrasound. Finally, laser scanning confocal microscope images showed that there was a significant difference in MDR1 mRNA expression in K562 and K562/Adr cells, which was consistent with the results of q-PCR measurement. In summary, optimized MDR1 molecular beacon designed in this study is a reliable strategy for detection MDR1 mRNA expression in living tumor cells, and will be a promising strategy for in guiding patient treatment and management in individualized medication.

  15. THE CLINICAL SIGNIFICANCE OF MULTIDRUG RESISTANCE GENE (mdr1) EXPRESSION IN ACUTE LEUKEMIA

    Institute of Scientific and Technical Information of China (English)

    Dong Zuoren; Cong Bin; Luo Jianmin; Xu Wenxin; Wang Fuxu; Guo Xiaonan; Zhang Xuejun; Yao Ergu; Xu Shirong; Ren Jinhai

    1998-01-01

    Objective: To study the clinical significance of multidrug resistance gene expression in acute leukemia.Methods: The relationships between drug resistance of leukemia cells and prognosis, multidrug resistance gene (mdr1) were examined in 85 patients with acute leukemia and 20 normal controls by reverse transcriptase polymerase chain reaction (RT-PCR). Results: The mdr1 positive rate in untreated group was 44.7 %. The complete remission (CR) rate of mdr1 positive patients (23.9 %) was significantly lower than that of mdr1 negative patients(88.5 %) (P<0.005). The mdr1 expression level in relapsedrefractory group was higher than that of CR group. A gradually increased mdr1 mRNA level in CR patients indicated early relapse. Conclusion: The mdr1 positive rate in normal control and long-term survival patients was very low. The mdr1 expression was correlated with French-American-British Cooperative Group (FAB)classification. The mdr1 expression level was correlated with chemotherapeutic effect and prognosis. It is an unfavorable prognostic factor for patients with acute leukemia.

  16. Prognostic significance of MDR-1 P-glycoprotein expression in breast cancer

    Institute of Scientific and Technical Information of China (English)

    Huilin Zhang; Wandong Zhang; Fengshan Li

    2008-01-01

    Objective: To investigate the expression of MDR-1 P-glycoprotein(MDR-1 Pgp) in breast cancer and analyze its correlation to the biological behavior and prognosis of the disease. Methods:The expression of MDR-1 Pgp was examined in 75 cases of breast cancer patients by using three different monoclonal antibodies0SBl, C219 and C494) with S-P immunohistochemisty. These patients were followed up for 5 years, and the correlation between MDR-1 Pgp expression, survival rate and lymph metastasis was analyzed. Results:Positive detection of MDR-1 Pgp by JSB 1, C219 and C494 in 75 cases of breast cancer was 86.7%, 48% and 85.3%, respectively.MDR-1 Pgp expression was not related to ages of patients (P>0.05). JSB 1-detected expression of MDR-1 Pgp was related to lymph node metastasis(P<0.05); while C219 and (2494 were not(P>0.05). The patients with MDR-1 Pgp expression positively detected by either two of the three antibodies, had five-year survival rate that was significantly higher than those positively detected by all the three antibodies(P<0.05). Conclusion:Three antibodies should be used simultaneously to detect MDR-1 Pgp expression in breast cancer.Positive MDR-1 Pgp expression in breast cancer detected by all the three antibodies may represent a poor prognosis; while positive MDR-1 Pgp detection by JSB1 and C494 is associated with lymph metastasis.

  17. EFFECTS OF NEOADJUVANT CHEMOTHERAPY ON MDR1 AND MRP GENE EXPRESSION IN PRIMARY BREAST CANCER

    Institute of Scientific and Technical Information of China (English)

    刘杏娥; 孙晓东; 吴金民

    2004-01-01

    Objective: To investigate the effects of neoadjuvant chemotherapy on the expression of drug resistance genes,multidrug resistance-1 (MDR1) and multidrug resistance-associated protein (MRP), in patients with primary breast cancer. Methods: MDR1 and MRP expression were detected by semi-quantitative RT-PCR in 20 patients with primary breast cancer, before and after chemotherapy.Results: Before chemotherapy, MDR1 and MRP expression can be detected in 15 cases (75%) and 18 cases (90%)respectively. After chemotherapy, expression of MDR1 is not significantly different from that before chemotherapy, but expression of MRP is significantly different from that before chemotherapy. Conclusion: Expression of drug resistance gene MRP, but not MDR1, is enhanced in patients with primary breast cancer submitted to neoadjuvant chemotherapy.

  18. THE DETECTION OF MDR1 GENE EXPRESSION USING FLUOROGENIC PROBE QUANTITATIVE RT-PCR METHOD

    Institute of Scientific and Technical Information of China (English)

    高劲松; 马刚; 仝明; 陈佩毅; 王传华; 何蕴韶

    2001-01-01

    Objective: To establish a fluoregenic probe quantitative RT-PCR (FQ-RT-PCR) method for detection of the expression of MDR1 gene in tumor cells and to investigate the expression of MDR1 gene in patients with lung cancer. Methods: The fluorogenic quantitative RT-PCR method for detection of the expression of MDR1 gene was established. K562/ADM and K562 cell lines or 45 tumor tissues from patients with lung cancer were examined on PE Applied Biosystems 7700 Sequence Detection machine. Results: the average levels of MDR1 gene expression in K562/ADM cells and K562 cells were (6.86±0.65)× 107copies/mg RNA and (8.49±0.67)×105 copies/mg RNA, respectively. The former was 80.8 times greater than the latter. Each sample was measured 10 times and the coefficient variation (CV) was 9.5% and 7.9%, respectively. Various levels of MDR1 gene expression were detected in 12 of 45 patients with lung cancer. Conclusion: Quantitative detection of MDR1 gene expression in tumor cells was achieved by using FQ-RT-PCR. FQ-RT-PCR is an accurate, and sensitive method and easy to perform. Using this method, low levels of MDR1 gene expression could be detected in 24% of the patients with lung cancer.

  19. A new model for studying tissue-specific mdr1a gene expression in vivo by live imaging

    OpenAIRE

    Gu, Long; Tsark, Walter M.; Brown, Donna A.; Blanchard, Suzette; Synold, Timothy W.; Kane, Susan E

    2009-01-01

    Multidrug resistance continues to be a major impediment to successful chemotherapy in cancer patients. One cause of multidrug resistance is enhanced expression of the mdr1 gene, but the precise factors and physiological conditions controlling mdr1 expression are not entirely known. To gain a better understanding of mdr1 transcriptional regulation, we created a unique mouse model that allows noninvasive bioimaging of mdr1 gene expression in vivo and in real time. The model uses a firefly lucif...

  20. Paclitaxel sensitivity in relation to ABCB1 expression, efflux and single nucleotide polymorphisms in ovarian cancer

    OpenAIRE

    Gao, Bo; Russell, Amanda; Beesley, Jonathan; Chen, Xiao Qing; Healey, Sue; Henderson, Michelle; Wong, Mark; Emmanuel, Catherine; Johnatty, Sharon E.; ,; Bowtell, David; Gertig, Dorota; Green, Adle; Webb, Penelope; Hung, Jillian

    2014-01-01

    ABCB1 (adenosine triphosphate-binding cassette transporter B1) mediates cellular elimination of many chemotherapeutic agents including paclitaxel, which is commonly used to treat ovarian cancer. A significant association between common single nucleotide polymorphisms (SNPs) in ABCB1 and progression-free survival has been reported in patients with ovarian cancer. Variable paclitaxel clearance due to genotype specific differences in ABCB1 activity in cancer cells and/or normal tissues may under...

  1. Quantitative analysis of MDR1 (multidrug resistance) gene expression in human tumors by polymerase chain reaction.

    OpenAIRE

    Noonan, K E; Beck, C.; Holzmayer, T A; Chin, J E; Wunder, J.S.; Andrulis, I.L.; Gazdar, A F; Willman, C.L.; Griffith, B.; Von Hoff, D. D.

    1990-01-01

    The resistance of tumor cells to chemotherapeutic drugs is a major obstacle to successful cancer chemotherapy. In human cells, expression of the MDR1 gene, encoding a transmembrane efflux pump (P-glycoprotein), leads to decreased intracellular accumulation and resistance to a variety of lipophilic drugs (multidrug resistance; MDR). The levels of MDR in cell lines selected in vitro have been shown to correlate with the steady-state levels of MDR1 mRNA and P-glycoprotein. In cells with a severa...

  2. Significant activity of ecdysteroids on the resistance to doxorubicin in mammalian cancer cells expressing the human ABCB1 transporter.

    Science.gov (United States)

    Martins, Ana; Tóth, Noémi; Ványolós, Attila; Béni, Zoltán; Zupkó, István; Molnár, József; Báthori, Mária; Hunyadi, Attila

    2012-06-14

    Multidrug resistance (MDR) is a major cause of failure of cancer chemotherapy. Fifty-eight ecdysteroids, herbal analogues of the insect molting hormone and their semisynthetic derivatives, were tested for their activity against L5178 mouse T-cell lymphoma cells (non-MDR) and their subcell line transfected with pHa MDR1/A retrovirus overexpressing the human ABCB1 efflux pump (MDR cell line). The compounds showed very low antiproliferative activities but modulated the efflux of rhodamine 123 mediated by the ABCB1 transporter. Roughly depending on the polarity, mild to strong synergism or antagonism was observed by combining ecdysteroids with doxorubicin, and specific structure-activity relationships were also found. Our results show the effect of ecdysteroids on MDR cancer cells for the first time. Less polar derivatives may serve as valuable leads toward a potent and safe resistance modulator. Biological significance of the resistance-increasing activity of the most abundant phytoecdysteroids including 20-hydroxyecdysone is yet to be clarified. PMID:22578055

  3. ESTABLISHMENT OF CRITERIA FOR MEASURING MDR-1 GENE EXPRESSION LEVEL IN BREAST CANCER BY RT-PCR

    Institute of Scientific and Technical Information of China (English)

    Liu Xiaoqing; Song Santai; Shi Chenghua; Xu Jianming; Tang Zhongming; Jiang Zefei

    1998-01-01

    Objective: To formulate criteria of multidrug resistance (mdr-1) gene expression for predicting chemotherapy response and prognosis. Methods: Using reverse transcription-polymerase chain reaction (RTPCR) assay, the expression of mdr-1 gene in 82 breast cancer samples were detected. Results: The data were treated by statistic analysis system (SAS)-singlevariate analysis. It showed that the level of mdr-1 gene expression clearly deviated from normal to right distribution (P<0.0001), and thus might be divided by quantiles P50(mdr-1/β 2-MG=0.2) and P75 (mdr-1/β 2-MG=0.6), which were taken as the preliminary criteria for analyzing 56 patients' chemosensitivity to ADM、 VDS and VCR in vitro and 32 relapsed metastatic patients' chemotherapy response in vivo, seperately. When mdr-1/β 2-MG<0.2, the ratios of resistance gradually escalated, but there were about 30%~50% of the cases who showed sensitive to the drugs in vitro and effective to chemotherapy in vivo. When mdr-1/β 2-MG≥0.6, the most of patients showed drug resistance both in vitro and in vivo. Conclusion:According to the above-mentioned results, criteria of evaluating mdr-1 gene expression level was formulated:the mdr-1/β 2-MG<0.2 (P50) was considered as negative expression, the ratio≥0.2~<0.6 (P75) was weakly positive expression, ≥0.6 was strongly positive expression. This indicated that different levels of mdr-1 gene expression may reflect objectively drug resistance in vitro and chemotherapy response in vivo.

  4. OCT-1, ABCB1, and ABCG2 Expression in Imatinib-Resistant Chronic Myeloid Leukemia Treated with Dasatinib or Nilotinib

    OpenAIRE

    Kim, Yeo-Kyeoung; Lee, Seung-Shin; Jeong, Sung-Hoon; Ahn, Jae-Sook; Yang, Deok-Hwan; Lee, Je-Jung; Shin, Myung-Geun; Kim, Hyeoung-Joon

    2014-01-01

    This study explored drug transporter expression levels and their impact on clinical response to imatinib and second-generation tyrosine kinase inhibitors (TKIs) in imatinib- resistant chronic myeloid leukemia (CML). Imatinib-resistant chronic phase CML patients treated with dasatinib (n=10) and nilotinib (n=12) were enrolled. The mRNA expression of the OCT-1, ABCG2, and ABCB1 genes was quantified by using paired bone marrow samples obtained before administering imatinib and at the point of de...

  5. Reversal of MDR1 gene-dependent multidrug resistance using short hairpin RNA expression vectors

    Institute of Scientific and Technical Information of China (English)

    GAN Hui-zhu; ZHENG De-ming; ZHANG Gui-zhen; ZHAO Ji-sheng; ZHANG Feng-chun; BU Li-sha; YANG Shao-juan; PIAO Song-lan; DU Zhen-wu; GAO Shen

    2005-01-01

    Background RNA interference using short hairpin RNA (shRNA) can mediate sequence-specific inhibition of gene expression in mammalian cells. A vector-based approach for synthesizing shRNA has been developed recently. Overexpression of P-glycoprotein (P-gp), the MDR1 gene product, confers multidrug resistance (MDR) to cancer cells. In this study, we reversed MDR using shRNA expression vectors in a multidrug-resistant human breast cancer cell line (MCF-7/AdrR). Methods The two shRNA expression vectors were constructed and introduced into MCF-7/AdrR cells. Expression of MDR1 mRNA was assessed by RT-PCR, and P-gp expression was determined by Western Blot and immunocytochemistry. Apoptosis and sensitization of the breast cancer cells to doxorubicin were quantified by flow cytometry and methyl thiazolyl tetrazolium (MTT) assays, respectively. Cellular daunorubicin accumulation was assayed by laser confocal scanning microscopy (LCSM). Statistical significance of differences in mean values was evaluated by Student's t tests. P<0.05 was considered statistically significant.Results In MCF-7/AdrA cells transfected with MDR1-A and MDR1-B shRNA expression vectors, RT-PCR showed that MDR1 mRNA expression was reduced by 40.9% (P<0.05), 30.1% (P<0.01) (transient transfection) and 37.6 % (P<0.05), 28.0% (P<0.01) (stable transfection), respectively. Western Blot and immunocytochemistry showed that P-gp expression was significantly and specifically inhibited. Resistance against doxorubicin was decreased from 162-fold to 109-fold (P<0.05), 54-fold (P<0.01) (transient transfection) and to 108-fold (P<0.05), 50-fold (P<0.01) (stable transfection). Furthermore, shRNA vectors significantly enhanced the cellular daunorubicin accumulation. The combination of shRNA vectors and doxorubicin significantly induced apoptosis in MCF-7/AdrR cells. Conclusions shRNA expression vectors effectively reduce MDR expression in a sustained fashion and can restore the sensitivity of drug-resistant cancer

  6. Validation of a P-Glycoprotein (P-gp Humanized Mouse Model by Integrating Selective Absolute Quantification of Human MDR1, Mouse Mdr1a and Mdr1b Protein Expressions with In Vivo Functional Analysis for Blood-Brain Barrier Transport.

    Directory of Open Access Journals (Sweden)

    Muhammad Waqas Sadiq

    Full Text Available It is essential to establish a useful validation method for newly generated humanized mouse models. The novel approach of combining our established species-specific protein quantification method combined with in vivo functional studies is evaluated to validate a humanized mouse model of P-gp/MDR1 efflux transporter. The P-gp substrates digoxin, verapamil and docetaxel were administered to male FVB Mdr1a/1b(+/+ (FVB WT, FVB Mdr1a/1b(-/- (Mdr1a/1b(-/-, C57BL/6 Mdr1a/1b(+/+ (C57BL/6 WT and humanized C57BL (hMDR1 mice. Brain-to-plasma total concentration ratios (Kp were measured. Quantitative targeted absolute proteomic (QTAP analysis was used to selectively quantify the protein expression levels of hMDR1, Mdr1a and Mdr1b in the isolated brain capillaries. The protein expressions of other transporters, receptors and claudin-5 were also quantified. The Kp for digoxin, verapamil, and docetaxel were 20, 30 and 4 times higher in the Mdr1a/1b(-/- mice than in the FVB WT controls, as expected. The Kp for digoxin, verapamil and docetaxel were 2, 16 and 2-times higher in the hMDR1 compared to the C57BL/6 WT mice. The hMDR1 mice had 63- and 9.1-fold lower expressions of the hMDR1 and Mdr1a proteins than the corresponding expression of Mdr1a in C57BL/6 WT mice, respectively. The protein expression levels of other molecules were almost consistent between C57BL/6 WT and hMDR1 mice. The P-gp function at the BBB in the hMDR1 mice was smaller than that in WT mice due to lower protein expression levels of hMDR1 and Mdr1a. The combination of QTAP and in vivo functional analyses was successfully applied to validate the humanized animal model and evaluates its suitability for further studies.

  7. ΔNp73α regulates MDR1 expression by inhibiting p53 function

    Science.gov (United States)

    Vilgelm, A; Wei, JX; Piazuelo, MB; Washington, MK; Prassolov, V; El-Rifai, W; Zaika, A

    2014-01-01

    The p73 protein is a transcription factor and member of the p53 protein family that expresses as a complex variety of isoforms. ΔNp73α is an N-terminally truncated isoform of p73. We found that ΔNp73 protein is upregulated in human gastric carcinoma suggesting that ΔNp73 may play an oncogenic role in these tumors. Although it has been shown that ΔNp73α inhibits apoptosis and counteracts the effect of chemotherapeutic drugs, the underlying mechanism by which this p73 isoform contributes to chemotherapeutic drug response remains to be explored. We found that ΔNp73α upregulates MDR1 mRNA and p-glycoprotein (p-gp), which is involved in chemotherapeutic drug transport. This p-gp upregulation was accompanied by increased p-gp functional activity in gastric cancer cells. Our data suggest that upregulation of MDR1 by ΔNp73α is mediated by interaction with p53 at the MDR1 promoter. PMID:17952118

  8. DeltaNp73alpha regulates MDR1 expression by inhibiting p53 function.

    Science.gov (United States)

    Vilgelm, A; Wei, J X; Piazuelo, M B; Washington, M K; Prassolov, V; El-Rifai, W; Zaika, A

    2008-04-01

    The p73 protein is a transcription factor and member of the p53 protein family that expresses as a complex variety of isoforms. DeltaNp73alpha is an N-terminally truncated isoform of p73. We found that DeltaNp73 protein is upregulated in human gastric carcinoma suggesting that DeltaNp73 may play an oncogenic role in these tumors. Although it has been shown that DeltaNp73alpha inhibits apoptosis and counteracts the effect of chemotherapeutic drugs, the underlying mechanism by which this p73 isoform contributes to chemotherapeutic drug response remains to be explored. We found that DeltaNp73alpha upregulates MDR1 mRNA and p-glycoprotein (p-gp), which is involved in chemotherapeutic drug transport. This p-gp upregulation was accompanied by increased p-gp functional activity in gastric cancer cells. Our data suggest that upregulation of MDR1 by DeltaNp73alpha is mediated by interaction with p53 at the MDR1 promoter.

  9. Expression of MDR1, HIF-1α and MRP1 in sacral chordoma and chordoma cell line CM-319

    Directory of Open Access Journals (Sweden)

    Ma Baoan

    2010-12-01

    Full Text Available Abstract Background Chordoma was a typically slow-growing tumor. The therapeutic approach to chordoma had traditionally relied mainly on surgical therapy. And the main reason for therapeutic failure was resistance to chemotherapy and radiotherapy. However the refractory mechanism was not clear. The aim of this study was to investigate the expression of three genes (MDR1, HIF-1α and MRP1 associated with resistance to chemotherapy and radiotherapy in chordoma and chordoma cell line CM-319. Materials and methods Using immunohistochemical techniques, the expression of MDR1, HIF-1α and MRP1 was investigated in 50 chordoma specimen. Using RT-PCR and Western blot, the expression of MDR1, HIF-1α and MRP1 was investigated in chordoma and chordoma cell line CM-319. Results Expression of MDR1, HIF-1α and MRP1 was observed in 10%, 80% and 74% of all cases, respectively. Expression of MRP1 was correlated with HIF-1α. On the other hand, expression of MDR1 was not correlated with the expression of HIF-1α or MRP1. The expression of HIF-1α and MRP1 was observed, but MDR1 was not observed in chordoma and CM-319. Conclusion Expression of HIF-1α and MRP1 was observed in most chordoma specimen and CM-319 cell line; expression of HIF-1α correlated with MRP1. HIF-1α and MRP1 may play a role in the multidrug resistance of chordoma to chemotherapy.

  10. Downregulation of gene MDR1 by shRNA to reverse multidrug-resistance of ovarian cancer A2780 cells

    Directory of Open Access Journals (Sweden)

    Hongyi Zhang

    2012-01-01

    Full Text Available Background: To explore the effects of downregulated multidrug-resistance P-glycoprotein (MDR1/ABCB1 and reversed multidrug-resistance in human A2780 ovarian cancer cells. Materials and Methods: Three shRNAs targeting the MDR1 gene were synthesized, and cloned into plasmid pSUPER-enhanced green fluorescent protein 1 (EGFP1. The formed pSUPER-EGFP1-MDR1-shRNAs were transfected into the A2780 cells, respectively, and the quantitative reverse transcription polymerase chain reaction and western blot were used respectively to determine the MDR1 expression. The multidrug-resistance (MDR of the MDR1-shRNAs transfected A2780 cells to chemotherapy drugs in vitro and in tumor-bearing nude mice were respectively evaluated. Results: The MDR1 shRNA expression resulted in decreased P-glycoprotein expression in the transfected A2780 cells. The MDR1-shRNA2 transfected cells showed that the sensitivities to chemotherapy drugs were higher than other shRNAs transfected A2780 cells, and that the formed tumor in mice grew slower than those of other mice after paclitaxel was injected into tumor-bearing nude mice. Conclusions: Our data demonstrates that the RNA interference could knock down gene MDR1 and reduce the P-glycoprotein expression, and partly reverse the MDR of A2780 cells in vitro and in vivo. These results suggest that MDR-1 is an effective therapeutic target for human ovarian caner treatment.

  11. Expression of GST-pi and MDR1 genes in operative specimens of ovarian cancer%卵巢癌组织中GST-π和MDR1基因的表达及其意义

    Institute of Scientific and Technical Information of China (English)

    卞丽红; 黄长江; 陈高明; 孙丽娅; 李春海; 傅才英; 李亚里

    2001-01-01

    Objectives:To study the expression of GST-pi and MDR1 genes in operative specimens of ovarian cancer,and to analyze the possible clinical role of GST-pi and MDR1. Methods:Eighteen frozen specimens of ovarian carcinoma and ten specimens of normal ovarian tissues from patients were examined for the expression of GST-pi and MDR1 genes by means of RT-PCR, and quantitative analysis was performed using β-actin as internal contrast.Results: Positive expression rate of GST-pi and MDR1 in ovarian carcinoma were 61.1% and 33.3%,respectively,and in contrast, 20% and 10% in normal ovarian tissues respectively. The level of GST-pi gene expression in ovarian carcinoma was obviously higher than that in normal ovarian tissue (P<0.05)and MDR1 gene also had high level expression in ovarian carcinoma, but had no statistical significantance. Four patients with ovarian carcinoma had GST-pi and MDR1 coexpression. Expression levels of GST-pi mRNA were lower than that of protein. Conclusions: (1) GST-pi and MDR1 had higher level expression in ovarian carcinoma than in normal ovarian tissues. (2) GST-pi and MDR1 may have same regulating factors but different mechanisms of action. (3)Processing after transcription and/or regulation of translation level may exist in GST-pi expression.%目的:观察两种耐药基因谷胱甘肽S-转移酶-pi(GST-π)和MDR1在卵巢癌组织中mRNA水平的表达情况,探讨其表达的意义及应用价值.方法:采用逆转录PCR方法检测了18例卵巢癌和10例正常卵巢组织中GST-π和MDR1的表达,应用β-肌动蛋白作为内对照进行定量分析比较.结果:GST-π和MDR1在正常卵巢组织中表达的阳性率分别是20%和10%,在卵巢癌中的阳性表达率分别是61.1%和33.3%.GST-π在癌组织表达高于正常组织,两者比较P<0.05;而MDR1在癌组织表达虽高于正常组织但无统计学意义;在癌组织中有4例同时出现了GST-π和MDR1的共表达;GST-π mRNA水平的表达低于蛋白水平的表达.结论:(1

  12. Tissue Distribution, Gender-Divergent Expression, Ontogeny, and Chemical Induction of Multidrug Resistance Transporter Genes (Mdr1a, Mdr1b, Mdr2) in Mice

    OpenAIRE

    Cui, Yue Julia; Cheng, Xingguo; Weaver, Yi Miao; Klaassen, Curtis D.

    2008-01-01

    Multidrug resistance (Mdr) transporters are ATP-binding cassette transporters that efflux amphipathic cations from cells and protect tissues from xenobiotics. Unfortunately, Mdr transporters also efflux anticancer drugs from some tumor cells, resulting in multidrug resistance. There are two groups of Mdrs in mice: group I includes Mdr1a and Mdr1b that transport xenobiotics, whereas group II is Mdr2, a flipase that facilitates phospholipid excretion into bile. Little is...

  13. Comparison of mdr1, ERCC2,and MGMT Expression in Human Glioma%人脑胶质瘤耐药基因mdr1、ERCC2、MGMT的表达及相关性分析

    Institute of Scientific and Technical Information of China (English)

    王爱东; 黄强; 罗良生; 陈忠平

    2001-01-01

    目的:探讨人脑胶质瘤组织中三种耐药基因mdr1、ERCC2和MGMTmRNA表达之间的相关性。方法:采用双管RT-PCR方法检测14例正常脑组织和56例人脑胶质瘤组织中mdr1、ERCC2和MGMTmRNA水平,并分析其相关性。结果:正常脑组织中mdr1、ERCC2和MGMT的表达量分别为(0.75±0.36),(1.43±0.92)和(2.48±1.83),mdr1和ERCC2、ERCC2和MGMT之间具相关性(P<0.01和P<0.001);胶质瘤组织中三种基因表达量分别为(0.53±0.42),(1.75±1.16)和(2.88±1.92),ERCC2和MGMT之间具极显著相关性(P<0.001)。结论:ERCC2和MGMT基因的表达之间可能具有内在的联系,共同参与细胞对DNA损伤的修复,并形成耐药;而mdr1与上述两者之间不具有这种关系。%Objective: This study was designed to evaluate the relationship among mdr1, ERCC2,and MGMT expression in human glioma. Methods: RT-PCR method was used to determine the mRNA levels of mdr1, ERCC2, and MGMT gene in 14 normal brain tissues and 56 human gliomas,and the relationship between these gene expression was analyzed. Results: In normal brain tissues, there was significant concordance between ERCC2 expression and mdr1 (P<0.01) expression or MGMT (P<0.001) expression. A significant correlation was also found between the expression of ERCC2 and MGMT in glioma specimens (P<0.001). Conclusion: The results suggest that there may be intrinsic relationship between ERCC2 and MGMT expression in human gliomas which affect DNA repair resulting in drug resistance.

  14. P-Glycoprotein/MDR1 Regulates Pokemon Gene Transcription Through p53 Expression in Human Breast Cancer Cells

    OpenAIRE

    Wei Xu; Yuyang Jiang; Xuyu Zu; Shengnan He; Zhenhua Xie; Feng Liu(Central China Normal University)

    2010-01-01

    P-glycoprotein (Pgp), encoded by the multidrug resistance 1 (MDR1) gene, is an efflux transporter and plays an important role in pharmacokinetics. In this study, we demonstrated that the pokemon promoter activity, the pokemon mRNA and protein expression can be significantly inhibited by Pgp. Chromatin immunoprecipitation assay showed that Pgp can bind the pokemon prompter to repress pokemon transcription activity. Furthermore, Pgp regulated pokemon transcription activity through expression of...

  15. THE AMPLIFICATION AND EXPRESSION OF MDR1 GENE IN ADRIAMYCINE RESISTANT CELL LINE OF COLON CANCER CELL HR8348

    Institute of Scientific and Technical Information of China (English)

    周中军; 罗贤懋; 林晨; 陈凤

    1996-01-01

    P-glycoprotein plays an important role in highly drug resistant cells. But its high expression cannot be acheived by chemotherapy. In order to study the effect of P-glycoprotein on clinical tumors, wo ostablished a low ADM resistant colon cancer ceil line HR/ADM and determined the amplification and expression of mdr-1 gene. The GLC/ADM showed a resistant pattern similar to classical MDR and the transcription of mdr-1 gene determined by RT-PCR increased. The immunocytcchemical analysis showed strong positive staining with monoelonal antibozly. The gene amplification of mdr-l was dearly demonstrated by southern blot. Our results suggested that moderate expression of P-glycoprotein might be enough for a high resistant pattern.

  16. Effects of Momordica charantia Extract on the Expression of MDR 1 Gene in Human Lung Cancer Cells

    Directory of Open Access Journals (Sweden)

    T Yuan

    2014-10-01

    Full Text Available Objectives: Multi-drug resistance (MDR is a major hurdle in treatment of cancer, contributing to the failure of chemotherapy. Drug resistance is found to be linked to the overexpression of ATP-binding cassette (ABC drug transporter proteins that include P-glycoprotein (P-gp, causing a reduction in drug accretion inside the cancer cells. In the present study, the effect of the extracts from the fruit peel and pulp of Momordica charantia (MCFPE fruit in modulating the function of P-gp in human small-cell lung cancer (SCLC cell lines was assessed. Methods: The effects of MCFPE were tested on drug-sensitive (H69 and multi-drug resistant (H69/LX4 human SCLC cells. The cell survival percentage was assessed by MTT cytotoxicity assay. The percentage of drug accumulation and drug efflux were assessed by using [3H]-paclitaxel. The expression of MDR1 gene was analysed by reverse transcription polymerase chain reaction (RT-PCR, and P-gp by western blot analysis. Results: The extract was able to induce death of cancer cells as measured by cell survival percentage as well as improve drug accumulation, as evidenced by intracellular paclitaxel retention. Prior exposure of cells to MCFPE reversed resistance to paclitaxel. Treatment with MCFPE was found to have a significant impact on MDR 1 gene expression in H69/LX4 cell line by decreasing its expression. The extract had no influence on expression of MDR 1 gene in the drug-sensitive SCLC cell lines. Western blot analysis of P-gp protein in H69 and H69/LX4 cells revealed that the treatment with the extract modulates the expression of MDR 1 in H69/LX4 and had negligible effect on H69 cells. Conclusion: The results indicate that MCFPE was able to effectively reverse multi-drug resistance and improve cancer chemotherapy.

  17. Preferential cytotoxicity of bortezomib toward highly malignant human liposarcoma cells via suppression of MDR1 expression and function

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Yamei; Wang, Lingxian; Wang, Lu; Wu, Xuefeng; Wu, Xudong [State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210093 (China); Gu, Yanhong; Shu, Yongqian [Department of Clinical Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029 (China); Sun, Yang [State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210093 (China); Shen, Yan, E-mail: shenyan@nju.edu.cn [State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210093 (China); Xu, Qiang, E-mail: molpharm@163.com [State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210093 (China)

    2015-02-15

    Liposarcoma is the most common soft tissue sarcoma with a high risk of relapse. Few therapeutic options are available for the aggressive local or metastatic disease. Here, we report that the clinically used proteasome inhibitor bortezomib exhibits significantly stronger cytotoxicity toward highly malignant human liposarcoma SW872-S cells compared with its parental SW872 cells, which is accompanied by enhanced activation of apoptotic signaling both in vitro and in vivo. Treatment of cells with Jun-N-terminal kinase (JNK) inhibitor SP60015 or the translation inhibitor cycloheximide ameliorated this enhanced apoptosis. Bortezomib inhibited MDR1 expression and function more effectively in SW872-S cells than in SW872 cells, indicating that the increased cytotoxicity relies on the degree of proteasome inhibition. Furthermore, the pharmacological or genetic inhibition of sarco/endoplasmic reticulum calcium-ATPase (SERCA) 2, which is highly expressed in SW872-S cells, resulted in partial reversal of cell growth inhibition and increase of MDR1 expression in bortezomib-treated SW872-S cells. These results show that bortezomib exhibits preferential cytotoxicity toward SW872-S cells possibly via highly expressed SERCA2-associated MDR1 suppression and suggest that bortezomib may serve as a potent agent for treating advanced liposarcoma. - Highlights: • We compare the cytotoxicity of different drugs between SW872-S and SW872 cells. • Highly malignant liposarcoma cells SW872-S show hypersensitivity to bortezomib. • Apoptotic signaling is robustly enhanced in bortezomib-treated SW872-S cells. • Bortezomib has strong suppression on MDR1 expression and function in SW872-S cells. • Inhibition of SERCA2 protects SW872-S cells from bortezomib.

  18. Decreased P-glycoprotein (P-gp/MDR1) expression in inflamed human intestinal epithelium is independent of PXR protein levels

    NARCIS (Netherlands)

    Blokzijl, Hans; Vander Borght, Sara; Bok, Lisette I. H.; Libbrecht, Louis; Geuken, Mariska; Van den Heuvel, Fiona A. J.; Dijkstra, Gerard; Roskams, Tonia A. D.; Moshage, Han; Jansen, Peter L. M.; Faber, Klaas Nico

    2007-01-01

    Background: Altered P-glycoprotein expression (P-gp/MDR1) and/or function may contribute to the pathogenesis of gastrointestinal inflammatory disorders. Low intestinal mRNA levels of the pregnane X receptor (PXR) have been linked to low MDR1 mRNA levels in patients with ulcerative colitis (UC). Here

  19. Sinomenine sensitizes multidrug-resistant colon cancer cells (Caco-2 to doxorubicin by downregulation of MDR-1 expression.

    Directory of Open Access Journals (Sweden)

    Zhen Liu

    Full Text Available Chemoresistance in multidrug-resistant (MDR cells over expressing P-glycoprotein (P-gp encoded by the MDR1 gene, is a major obstacle to successful chemotherapy for colorectal cancer. Previous studies have indicated that sinomenine can enhance the absorption of various P-gp substrates. In the present study, we investigated the effect of sinomenine on the chemoresistance in colon cancer cells and explored the underlying mechanism. We developed multidrug-resistant Caco-2 (MDR-Caco-2 cells by exposure of Caco-2 cells to increasing concentrations of doxorubicin. We identified overexpression of COX-2 and MDR-1 genes as well as activation of the NF-κB signal pathway in MDR-Caco-2 cells. Importantly, we found that sinomenine enhances the sensitivity of MDR-Caco-2 cells towards doxorubicin by downregulating MDR-1 and COX-2 expression through inhibition of the NF-κB signaling pathway. These findings provide a new potential strategy for the reversal of P-gp-mediated anticancer drug resistance.

  20. Glucosylceramide synthase upregulates MDR1 expression in the regulation of cancer drug resistance through cSrc and β-catenin signaling

    Directory of Open Access Journals (Sweden)

    Cabot Myles C

    2010-06-01

    Full Text Available Abstract Background Drug resistance is the outcome of multiple-gene interactions in cancer cells under stress of anticancer agents. MDR1 overexpression is most commonly detected in drug-resistant cancers and accompanied with other gene alterations including enhanced glucosylceramide synthase (GCS. MDR1 encodes for P-glycoprotein that extrudes anticancer drugs. Polymorphisms of MDR1 disrupt the effects of P-glycoprotein antagonists and limit the success of drug resistance reversal in clinical trials. GCS converts ceramide to glucosylceramide, reducing the impact of ceramide-induced apoptosis and increasing glycosphingolipid (GSL synthesis. Understanding the molecular mechanisms underlying MDR1 overexpression and how it interacts with GCS may find effective approaches to reverse drug resistance. Results MDR1 and GCS were coincidently overexpressed in drug-resistant breast, ovary, cervical and colon cancer cells; silencing GCS using a novel mixed-backbone oligonucleotide (MBO-asGCS sensitized these four drug-resistant cell lines to doxorubicin. This sensitization was correlated with the decreased MDR1 expression and the increased doxorubicin accumulation. Doxorubicin treatment induced GCS and MDR1 expression in tumors, but MBO-asGCS treatment eliminated "in-vivo" growth of drug-resistant tumor (NCI/ADR-RES. MBO-asGCS suppressed the expression of MDR1 with GCS and sensitized NCI/ADR-RES tumor to doxorubicin. The expression of P-glycoprotein and the function of its drug efflux of tumors were decreased by 4 and 8 times after MBO-asGCS treatment, even though this treatment did not have a significant effect on P-glycoprotein in normal small intestine. GCS transient transfection induced MDR1 overexpression and increased P-glycoprotein efflux in dose-dependent fashion in OVCAR-8 cancer cells. GSL profiling, silencing of globotriaosylceramide synthase and assessment of signaling pathway indicated that GCS transfection significantly increased globo series

  1. Prognostic Significance of Multidrug Resistance Gene 1 (MDR1), Multidrug Resistance-related Protein (MRP) and Lung Resistance Protein (LRP) mRNA Expression in Acute Leukemia

    OpenAIRE

    Huh, Hee Jin; Park, Chan-Jeoung; Jang, Seongsoo; Seo, Eul-Ju; Chi, Hyun-Sook; Lee, Je-Hwan; Lee, Kyoo-Hyung; Seo, Jong Jin; Moon, Hyung Nam; Ghim, Thad

    2006-01-01

    The prognostic significance of multidrug resistance (MDR) gene expression is controversial. We investigated whether multidrug resistance gene 1 (MDR1), multidrug resistance-related protein (MRP) and lung resistance protein (LRP) mRNA expression are associated with outcomes in acute leukemia patients. At diagnosis we examined MDR1, MRP and LRP mRNA expression in bone marrow samples from 71 acute leukemia patients (39 myeloid, 32 lymphoblastic) using nested RT-PCR. The expression of each of the...

  2. Involvement of CtBP1 in the Transcriptional Activation of the MDR1 Gene in Human Multidrug Resistant Cancer Cells

    OpenAIRE

    Jin, Wei; Scotto, Kathleen W.; Hait, William N.; Yang, Jin-Ming

    2007-01-01

    Drug resistance caused by overexpression of P-glycoprotein (P-gp), the MDR1 (ABCB1) gene product, limits the therapeutic outcome. Expression of MDR1 can be induced by divergent stimuli, and involves a number of transcriptional factors. We found that the expression of CtBP1 (C-terminal-binding protein 1), a transcriptional co-regulator, was increased (~4 – fold) in human multidrug resistant (MDR) cancer cell lines, NCI/ADR-RES and A2780/DX, as compared to their sensitive counterparts. Silencin...

  3. Decreased expression of the amplified mdr1 gene in revertants of multidrug-resistant human myelogenous leukemia K562 occurs without loss of amplified DNA.

    OpenAIRE

    Sugimoto, Y.; Roninson, I B; Tsuruo, T.

    1987-01-01

    Amplification and increased expression of the mdr1 gene associated with multidrug resistance in human tumors were found in multidrug-resistant sublines of human myelogenous leukemia K562 selected with vincristine (K562/VCR) or adriamycin (K562/ADM). In two revertant cell lines of K562/ADM, amplification of the mdr1 gene was maintained at the same level as in K562/ADM, but expression of the 4.5-kilobase mdr1 mRNA was greatly decreased, indicating that amplified genes may be inactivated at the ...

  4. Wallichinine reverses ABCB1-mediated cancer multidrug resistance.

    Science.gov (United States)

    Lv, Min; Qiu, Jian-Ge; Zhang, Wen-Ji; Jiang, Qi-Wei; Qin, Wu-Ming; Yang, Yang; Zheng, Di-Wei; Chen, Yao; Huang, Jia-Rong; Wang, Kun; Wei, Meng-Ning; Cheng, Ke-Jun; Shi, Zhi

    2016-01-01

    Overexpression of ABCB1 in cancer cells is one of the main reasons of cancer multidrug resistance (MDR). Wallichinine is a compound isolated from piper wallichii and works as an antagonist of platelet activiating factor receptor to inhibit the gathering of blood platelet. In this study, we investigate the effect of wallichinine on cancer MDR mediated by ABCB1 transporter. Wallichinine significantly potentiates the effects of two ABCB1 substrates vincristine and doxorubicin on inhibition of growth, arrest of cell cycle and induction of apoptosis in ABCB1 overexpressing cancer cells. Furthermore, wallichinine do not alter the sensitivity of non-ABCB1 substrate cisplatin. Mechanistically, wallichinine blocks the drug-efflux activity of ABCB1 to increase the intracellular accumulation of rhodamine 123 and doxorubicin and stimulates the ATPase of ABCB1 without alteration of the expression of ABCB1. The predicted binding mode shows the hydrophobic interactions of wallichinine within the large drug binding cavity of ABCB1. At all, our study of the interaction of wallichinine with ABCB1 presented herein provides valuable clues for the development of novel MDR reversal reagents from natural products. PMID:27508017

  5. MDR1 Gene Polymorphisms and Clinical Relevance%MDR1基因多态性及其临床相关性研究进展

    Institute of Scientific and Technical Information of China (English)

    李艳红; 王永华; 李燕; 杨凌

    2006-01-01

    体内外研究证明,人体中P-gp在药物的吸收、分布、代谢和排泄(ADME)过程中发挥了非常重要的作用.多药耐药基因MDR1(ABCB1)是P-gp的编码基因.药物基因组学和遗传药理学研究发现在不同个体中MDR1基因多态性与P-gp表达和功能的改变密切相关,而且这些多态位点存在基因型分布和等位基因频率的种族差异性.近几年,已陆续发现在MDR1基因中有50处单核苷酸多态性(SNPs)和3处插入与缺失多态性.随后,大量文献报道某些位点的SNPs如C3435T会使个体患病的易感性增加.因此人们相信,深入研究MDR1基因多态性与P-gp的生理和生化方面的相关性将对个体医疗有着非常深远的意义.文章总结了国外最新的研究进展并结合本实验室的工作着重讨论了4个方面:1)P-gp对药代动力学性质的影响;2)MDR1基因多态性及其对遗传药理学性质的影响;3)MDR1C3435T的单核苷酸多态性与P-gp表达和功能之间的相关性;4)MDR1基因多态性与人类某些疾病之间的相关性.%In vivo and in vitro studies have demonstrated that P-glycoprotein (P-gp) plays a very significant role in the ADME processes (absorption, distribution, metabolism, excretion) and drug-drug interaction (DDI) of drugs in humans. P-gp is the product of multidrug resistance gene (MDR1/ABCB1). Pharmacogenomics and pharmacogenetics studies have revealed that genetic polymorphisms of MDR1 are associated with alteration in P-gp expression and function in different ethnicities and subjects. By now, 50single nucleotide polymorphisms (SNPs) and 3 insertion/deletion polymorphisms have been found in the MDR1 gene. Some of them, such as C3435T, have been identified to be a risk factor for numerous diseases. It is believed that further understanding of the physiology and biochemistry of P-gp with respect to its genetic variations may be important for individualized pharmacotherapy.Therefore, based on the latest public information

  6. Sestamibi is a substrate for MDR1 and MDR2 P-glycoprotein genes

    Energy Technology Data Exchange (ETDEWEB)

    Joseph, Brigid; Malhi, Harmeet; Gupta, Sanjeev [Marion Bessin Liver Research Center, Albert Einstein College of Medicine, Ullmann 625, 1300 Morris Park Avenue, NY 10461, Bronx (United States); Bhargava, Kuldeep K.; Palestro, Christopher J. [Division of Nuclear Medicine, Long Island Jewish Medical Center, New York (United States); Schilsky, Michael L. [Division of Liver Diseases, Mount Sinai School of Medicine, New York (United States); Jain, Diwakar [Division of Nuclear Cardiology, MCP-Hahnemann University School of Medicine, Philadephia (United States)

    2003-07-01

    Technetium-99m sestamibi has attracted interest for assessment of the function of P-glycoproteins, which are well expressed in the liver and have roles in biliary transport and the removal of chemotherapeutic drugs. To further examine the cross-reactivity of {sup 99m}Tc-sestamibi for P-glycoprotein family members, we conducted studies in animals. Hepatobiliary secretion of {sup 99m}Tc-sestamibi was determined in normal FVB/N mice, mutant mice with specific P-glycoprotein deficiencies in the FVB/N background, normal Long-Evans Agouti (LEA) rats, and Long-Evans Cinnamon (LEC) rats with abnormal copper transport and liver disease but intact P-glycoprotein expression. After intrasplenic injection, {sup 99m}Tc-sestamibi was rapidly incorporated in the mouse and rat liver, with maximal accumulation after 102{+-}31 and 109{+-}16 s, respectively (P=NS). In normal mice and rats, 55%{+-}11% and 55%{+-}6%, respectively, of the maximal sestamibi activity was retained in the liver after 1 h (P=NS). In double knockout mice lacking both mdr1a and mdr1b homologs of the human MDR1 (ABCB1) gene, 88%{+-}11% of maximal sestamibi activity was retained in the liver after 1 h (P<0.001). In knockout mice deficient in either mdr1a gene or mdr2 (ABCB4) gene, biliary sestamibi excretion was also impaired, although this impairment was relatively less pronounced in ABCB4-deficient mice than in double knockout mice lacking both ABCB1 gene homologs (P<0.03). Hepatobiliary sestamibi excretion in LEC rats was not different from that in control normal rats, despite the presence of significant liver disease in the former. Hepatobiliary sestamibi excretion requires P-glycoproteins and is unperturbed in chronic liver disease. Sestamibi appears to be a substrate for both ABCB1 and ABCB4 genes, although the former utilizes it far more efficiently. Assessment of P-glycoprotein activity with sestamibi should consider how regulation of ABCB1 and related family members might modulate sestamibi incorporation

  7. The Transcription Factor Mrr1p Controls Expression of the MDR1 Efflux Pump and Mediates Multidrug Resistance in Candida albicans

    OpenAIRE

    Joachim Morschhäuser; Katherine S. Barker; Liu, Teresa T.; Julia BlaB-Warmuth; Ramin Homayouni; P David Rogers

    2007-01-01

    Constitutive overexpression of the MDR1 (multidrug resistance) gene, which encodes a multidrug efflux pump of the major facilitator superfamily, is a frequent cause of resistance to fluconazole and other toxic compounds in clinical Candida albicans strains, but the mechanism of MDR1 upregulation has not been resolved. By genome-wide gene expression analysis we have identified a zinc cluster transcription factor, designated as MRR1 (multidrug resistance regulator), that was coordinately upregu...

  8. Epigenetic mechanisms involved in differential MDR1 mRNA expression between gastric and colon cancer cell lines and rationales for clinical chemotherapy

    Directory of Open Access Journals (Sweden)

    Kim Kyung-Jong

    2008-08-01

    Full Text Available Abstract Background The membrane transporters such as P-glycoprotein (Pgp, the MDR1 gene product, are one of causes of treatment failure in cancer patients. In this study, the epigenetic mechanisms involved in differential MDR1 mRNA expression were compared between 10 gastric and 9 colon cancer cell lines. Methods The MDR1 mRNA levels were determined using PCR and real-time PCR assays after reverse transcription. Cytotoxicity was performed using the MTT assay. Methylation status was explored by quantification PCR-based methylation and bisulfite DNA sequencing analyses. Results The MDR1 mRNA levels obtained by 35 cycles of RT-PCR in gastric cancer cells were just comparable to those obtained by 22 cycles of RT-PCR in colon cancer cells. Real-time RT-PCR analysis revealed that MDR1 mRNA was not detected in the 10 gastric cancer cell lines but variable MDR1 mRNA levels in 7 of 9 colon cancer cell lines except the SNU-C5 and HT-29 cells. MTT assay showed that Pgp inhibitors such as cyclosporine A, verapamil and PSC833 sensitized Colo320HSR (colon, highest MDR1 expression but not SNU-668 (gastric, highest and SNU-C5 (gastric, no expression to paclitaxel. Quantification PCR-based methylation analysis revealed that 90% of gastric cancer cells, and 33% of colon cancer cells were methylated, which were completely matched with the results obtained by bisulfite DNA sequencing analysis. 5-aza-2'-deoxcytidine (5AC, a DNA methyltransferase inhibitor increased the MDR1 mRNA levels in 60% of gastric cells, and in 11% of colon cancer cells. Trichostatin A (TSA, histone deacetylase inhibitor increased the MDR1 mRNA levels in 70% of gastric cancer cells and 55% of colon cancer cells. The combined treatment of 5AC with TSA increased the MDR1 mRNA levels additively in 20% of gastric cancer cells, but synergistically in 40% of gastric and 11% of colon cancer cells. Conclusion These results indicate that the MDR1 mRNA levels in gastric cancer cells are significantly

  9. The proliferative effect on silencing of endogenetic mdr1 gene expression by RNA interference in ovarian cancer resistant strain SKOV3/TAXOL%RNAi沉默卵巢癌耐药细胞株SKOV3/TAXOL内源mdr1基因对细胞增生的影响

    Institute of Scientific and Technical Information of China (English)

    冯继良; 王红梅; 姚焕玲; 马传侠; 杜秀平

    2009-01-01

    Objective To construct the short hairpin RNA recombinant plasmids targeting mdr1 gene which expresses highly in ovarian cancer resistance strain SKOV3/TAXOL to silence endogenefic mdr1 gene expression and investigate the role of mdr1 gene in the development of resistant ovarian cancer. Methods The pGPU6/GFP/Neo-mdr1 were constructed by gene clone technology. The influence on proliferation and apoptosis were investigated by CCK-8 in SKOV3/TAXOL after transfected pGPU6/GFP/Neo-mdr1. Results The expression against mdr1 proteins were inhibited by pGPU6/GFP/Neo-mdr1. The cell proliferation were inhibited after transfected pGPU6/GFP/Neo-mdr1 by CCK-8. The apoptosis were observed in DAB experiments and the apoptosis rate increased. Conclusion mdr1 plays an important role in proliferation of resistant ovarian cancer and the short hairpin RNA of mdr1 can efficiently suppress mdr1 expression and enhance the apoptosis in SKOV3/ATAXOL.%目的 构建靶向于卵巢癌耐药细胞株中高表达的mdr1基因的短发夹状RNA重组质粒,研究其沉默卵巢癌耐药细胞株SKOV3/TAXOL内源mdr1基因对细胞增生的抑制作用.方法 运用基因克隆技术构建靶向于mdr1基因的重组质粒pGPU6/GFP/Neo-mdr1并转染至卵巢癌耐药细胞株SKOV3/TAXOL,CCK-8检测对SKOV3/TAXOL细胞增生的抑制作用.结果 构建的重组质粒pGPU6/GFP/Neo-mdr1能明显抑制mdr1基因的表达.CCK-8检测结果表明,转染重组质粒pGPU6/GFP/Neo-mdr1的SKOV3/TAXOL靶细胞的抑制率比对照组显著提高(P<0.05).pGPU6/GFP/Neo-mdr1明显抑制SKOV3/TAXOL细胞的增生.细胞凋亡检测显示,pGPU6/GFP/Neo-mdr1转染SKOV3/T后细胞凋亡增加,通过pGPU6/GFP/Neo-mdr1转染SKOV3/T促进凋亡的发生.结论 mdr1基因在耐药的卵巢癌细胞增生与凋亡过程中发挥作用,重组质粒pGPU6/GFP/Neo-mdr1可有效地抑制SKOV3/TAXOL细胞内源mdr1基因的表达和mRNA的转录,并抑制细胞的增生和促进凋亡的发生.

  10. P-Glycoprotein/MDR1 Regulates Pokemon Gene Transcription Through p53 Expression in Human Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    Wei Xu

    2010-08-01

    Full Text Available P-glycoprotein (Pgp, encoded by the multidrug resistance 1 (MDR1 gene, is an efflux transporter and plays an important role in pharmacokinetics. In this study, we demonstrated that the pokemon promoter activity, the pokemon mRNA and protein expression can be significantly inhibited by Pgp. Chromatin immunoprecipitation assay showed that Pgp can bind the pokemon prompter to repress pokemon transcription activity. Furthermore, Pgp regulated pokemon transcription activity through expression of p53 as seen by use of p53 siRNA transfected MCF-7 cells or p53 mutated MDA-MB-231 cells. Moreover, p53 was detected to bind with Pgp in vivo using immunoprecipitation assay. Taken together, we conclude that Pgp can regulate the expression of pokemon through the presence of p53, suggesting that Pgp is a potent regulator and may offer an effective novel target for cancer therapy.

  11. P-Glycoprotein/MDR1 regulates pokemon gene transcription through p53 expression in human breast cancer cells.

    Science.gov (United States)

    He, Shengnan; Liu, Feng; Xie, Zhenhua; Zu, Xuyu; Xu, Wei; Jiang, Yuyang

    2010-01-01

    P-glycoprotein (Pgp), encoded by the multidrug resistance 1 (MDR1) gene, is an efflux transporter and plays an important role in pharmacokinetics. In this study, we demonstrated that the pokemon promoter activity, the pokemon mRNA and protein expression can be significantly inhibited by Pgp. Chromatin immunoprecipitation assay showed that Pgp can bind the pokemon prompter to repress pokemon transcription activity. Furthermore, Pgp regulated pokemon transcription activity through expression of p53 as seen by use of p53 siRNA transfected MCF-7 cells or p53 mutated MDA-MB-231 cells. Moreover, p53 was detected to bind with Pgp in vivo using immunoprecipitation assay. Taken together, we conclude that Pgp can regulate the expression of pokemon through the presence of p53, suggesting that Pgp is a potent regulator and may offer an effective novel target for cancer therapy. PMID:20957096

  12. ABCB1 gene polymorphisms is not associated with drug-resistant epilepsy in Romanian children

    Directory of Open Access Journals (Sweden)

    Butila Anamaria Todoran

    2015-12-01

    Full Text Available Background: P-glycoprotein (P-gp, a drug efflux transporter, encoded by the gene MDR1 ABCB1 multidrug resistant, reduces the penetration through the brain by the AEDs. Overexpression of Pgp in blood-brain barrier in epileptic patients play an important rol in pharmacoresistance. The aim of this study was to evaluate a possible association between C1236T and G2677T ABCB1 gene polymorphisms and drug-resistant epilepsy in Romanian children.

  13. Protein phosphatase complex PP5/PPP2R3C dephosphorylates P-glycoprotein/ABCB1 and down-regulates the expression and function.

    Science.gov (United States)

    Katayama, Kazuhiro; Yamaguchi, Miho; Noguchi, Kohji; Sugimoto, Yoshikazu

    2014-04-01

    P-glycoprotein (P-gp)/ABCB1 is a key molecule of multidrug resistance in cancer. Protein phosphatase (PP) 2A, regulatory subunit B, gamma (PPP2R3C), which is a regulatory subunit of PP2A and PP5, was identified as a binding candidate to P-gp. Immunoprecipitation-western blotting revealed that PP5 and PPP2R3C were coprecipitated with P-gp, while PP2A was not. PP5/PPP2R3C dephosphorylated protein kinase A/protein kinase C-phosphorylation of P-gp. Knockdown of PP5 and/or PPP2R3C increased P-gp expression and lowered the sensitivity to vincristine and doxorubicin. Consequently, our results indicate that PP5/PPP2R3C negatively regulates P-gp expression and function.

  14. Opioid-induced respiratory depression: ABCB1 transporter pharmacogenetics.

    Science.gov (United States)

    Sadhasivam, S; Chidambaran, V; Zhang, X; Meller, J; Esslinger, H; Zhang, K; Martin, L J; McAuliffe, J

    2015-04-01

    Opioid-related respiratory depression (RD) is a serious clinical problem as it causes multiple deaths and anoxic brain injuries. Morphine is subject to efflux via P-glycoprotein transporter encoded by ABCB1, also known as MDR1. ABCB1 polymorphisms may affect blood-brain barrier transport of morphine and therefore individual response to its central analgesic and adverse effects. This study aimed to determine specific associations between common ABCB1 genetic variants and clinically important outcomes including RD and RD resulting in prolonged stay in hospital with intravenous morphine in a homogenous pediatric surgical pain population of 263 children undergoing tonsillectomy. Children with GG and GA genotypes of ABCB1 polymorphism rs9282564 had higher risks of RD resulting in prolonged hospital stays; adding one copy of the minor allele (G) increased the odds of prolonged hospital stay due to postoperative RD by 4.7-fold (95% confidence interval: 2.1-10.8, P=0.0002). PMID:25311385

  15. Expression of a full-length cDNA for the human MDR1 gene confers resistance to colchicine, doxorubicin, and vinblastine

    International Nuclear Information System (INIS)

    Intrinsic and acquired multidrug resistance (MDR) is an important problem in cancer therapy. MDR in human KB carcinoma cells selected for resistance to colchicine, vinblastine, or doxorubicin (former generic name adriamycin) is associated with overexpression of the MDR1 gene, which encodes P-glycoprotein. The authors previously have isolated an overlapping set of cDNA clones for the human MDR1 gene from multidrug-resistant KB cells. Here they report the construction of a full-length cDNA for the human MDR1 gene and show that this reconstructed cDNA, when inserted into a retroviral expression vector containing the long terminal repeats of Moloney leukemia virus or Harvey sarcoma virus, functions in mouse NIH 3T3 and human KB cells to confer the complete multidrug-resistance phenotype. These results suggest that the human MDR1 gene may be used as a positive selectable marker to introduce genes into human cells and to transform human cells to multidrug resistance without introducing nonhuman antigens

  16. UMMS-4 enhanced sensitivity of chemotherapeutic agents to ABCB1-overexpressing cells via inhibiting function of ABCB1 transporter.

    Science.gov (United States)

    Qiao, Dongjuan; Tang, Shangjun; Aslam, Sana; Ahmad, Matloob; To, Kenneth Kin Wah; Wang, Fang; Huang, Zhencong; Cai, Jiye; Fu, Liwu

    2014-01-01

    Multidrug resistance (MDR) mediated by ATP-binding cassette (ABC) transporters through efflux of antineoplastic agents from cancer cells is a major obstacle to successful cancer chemotherapy. The inhibition of these ABC transporters is thus a logical approach to circumvent MDR. There has been intensive research effort to design and develop novel inhibitors for the ABC transporters to achieve this goal. In the present study, we evaluated the ability of UMMS-4 to modulate P-glycoprotein (P-gp/ABCB1)-, breast cancer resistance protein (BCRP/ABCG2)- and multidrug resistance protein (MRP1/ABCC1)-mediated MDR in cancer cells. Our findings showed that UMMS-4, at non-cytotoxic concentrations, apparently circumvents resistance to ABCB1 substrate anticancer drugs in ABCB1-overexpressing cells. When used at a concentration of 20 μmol/L, UMMS-4 produced a 17.53-fold reversal of MDR, but showed no effect on the sensitivity of drug-sensitive parental cells. UMMS-4, however, did not significantly alter the sensitivity of non-ABCB1 substrates in all cells and was unable to reverse ABCG2- and ABCC1-mediated MDR. Additionally, UMMS-4 profoundly inhibited the transport of rhodamine 123 (Rho 123) and doxorubicin (Dox) by the ABCB1 transporter. Furthermore, UMMS-4 did not alter the expression of ABCB1 at the mRNA and protein levels. In addition, the results of ATPase assays showed that UMMS-4 stimulated the ATPase activity of ABCB1. Taken together, we conclude that UMMS-4 antagonizes ABCB1-mediated MDR in cancer cells through direct inhibition of the drug efflux function of ABCB1. These findings may be useful for the development of safer and more effective MDR modulator. PMID:24660104

  17. Novel understanding of ABC transporters ABCB1/MDR/P-glycoprotein, ABCC2/MRP2, and ABCG2/BCRP in colorectal pathophysiology

    DEFF Research Database (Denmark)

    Andersen, Vibeke; Svenningsen, Katrine; Knudsen, Lina Almind;

    2015-01-01

    transporter proteins, inflammatory bowel disease, ulcerative, colitis, Crohns disease, colorectal cancer, colitis, intestinal inflammation, intestinal carcinogenesis, ABCB1/P-glycoprotein (P-gp/CD243/MDR1), ABCC2/multidrug resistance protein 2 (MRP2) and ABCG2/breast cancer resistance protein (BCRP), Abcb1....../Mdr1a, abcc2/Mrp2, abcg2/Bcrp, knock-out mice, tight junction, membrane lipid function. RESULTS: Recently, human studies reported that changes in the levels of ABC transporters were early events in the adenoma-carcinoma sequence leading to CRC. A link between ABCB1, high fat diet and gut microbes...

  18. 化疗对小鼠腹水S180细胞及外周血淋巴细胞获得性MDR1表达的相关研究%The study of obtained cellular MDR1expression and apoptosis of mouse ascites S180 cell and its peripheral lymphocytestimulated by chemotherapy

    Institute of Scientific and Technical Information of China (English)

    尹格平; 陈铭; 陈诵芬; 朱彤宇; 刘艳梅

    2001-01-01

    目的:建立获得性多药耐药(MDR)表达小鼠腹水模型,探讨检测S180细胞和外周血淋巴细胞MDR1表达水平及凋亡指标的意义。方法:给予S180细胞荷瘤小鼠反复定量联合化疗刺激,用流式细胞术动态检测S180细胞和同期外周血淋巴细胞MDR1表达水平及凋亡指标结果:(1)实验组小鼠S180自化疗后1周MDR1表达逐渐增高,第5周后显著增加(P<0.05);而细胞凋亡率、细胞杀伤率及Fas因子表达率则随化疗时间的延长而逐渐下降,且MDR1表达显著增加时,S180细胞凋亡率等则显著降低(P<0.05);(2)实验组外周血淋巴细胞MDR1、细胞凋亡水平与S180细胞显著相关。结论:小鼠S180细胞多药耐药模型有助于获得在体研究MDR1表达的经验,经数疗程化疗后外周血淋巴细胞MDR1表达能够反映S180细胞MDR1表达的水平。%Objective:To establish the mouse model of MDR1 expression in ascites with S180cell and study the method to indicate the MDR1 expression(P170) and apoptotic parameters in ascites with S180 cells and the peripheral lymphocyte.Methods:The mice with S180 cell in ascites were stimulated with repeated-combined-chemotherapy(RCC),the contents of MDR1 expression(P170)and apoptotic parameters were repeatedly assayed by flow cytometry.The above parameters of peripheral lymphocyte(PL)were assayed at the same time.Results: (1)The cellular MDR1 expression(p170 content)of mice in study group were gradually improved after one week's RCC,and there was statistically differenceafter five weeks from that in control group;By the mean time,the cellular apoptotic rate,cellular-killed rate and Fas factor expression were gradually decreased along with the progress of RCC;(2)In study group the MDR1 expression and apoptotic rate of PL of mice were statistically correlated with those of S180 cells. Conclusions:The mouse model with obtained(secondary)cellular MDR1 expression of S180 cell line is helpful to study the

  19. Expressions of MDR1, MRP, and Fas in acute leukemia and their clinical significance%急性白血病中MDR1 MRP和Fas表达及其临床意义

    Institute of Scientific and Technical Information of China (English)

    李拴明; 叶芳; 郭宏锋; 麻生文

    2006-01-01

    目的研究多药耐药基因(MDR1)、多药耐药相关蛋白基因(MRP)和诱导凋亡的因子Fas在急性白血病(AL)的表达及它们与临床耐药的关系.方法采用流式细胞仪(FCM)直接免疫荧光法和半定量多聚酶链反应(RT-PCR)测定51例AL患者骨髓单个核细胞三种指标的表达情况.结果51例AL患者中MDR1/MRP/Fas三者共表达阳性率为11.76%,MDR1/MRP/Fas三者表达均阴性发生率为23.53%.三指标表达全阴性的患者75%获得完全缓解(CR),MDR+/MRP+/Fas+的患者84.21%获得CR,MDR+/MRP+/Fas-或MDR+/MRP+无一人CR(P<0.01).单指标分析表明MDR1、MRP和Fas表达阳性率分别为21.15%、32.69%和65.38%.MDR1阳性者CR率18.18%,明显低于MDR1阴性者72.50%(P<0.01);MRP阳性者CR率29.41%,明显低于MRP阴性者76.47%(P<0.01);Fas阳性者CR率63.64%,略高于Fas阴性者55.56%,但二者无显著性差异.结论MDR1+/MRP+或MDR1+/MRP+/Fas-者不易获CR,白血病患者的耐药除了与MDR1高表达密切相关外,还与非P-糖蛋白(P-gp)介导的MRP及Fas表达等因素相关.

  20. Evaluation of mRNA Expression Levels of cyp51A and mdr1, Candidate Genes for Voriconazole Resistance in Aspergillus flavus

    OpenAIRE

    Fattahi, Azam; Zaini, Farideh; Kordbacheh, Parivash; Rezaie, Sasan; Safara, Mahin; Fateh, Roohollah; Farahyar, Shirin; Kanani, Ali; Heidari, Mansour

    2015-01-01

    Background: Voriconazole Resistance (VRC-R) in Aspergillus flavus isolates impacts the management of aspergillosis, since azoles are the first choice for prophylaxis and therapy. However, to the best of our knowledge, the mechanisms underlying voriconazole resistance are poorly understood. Objectives: The present study was designed to evaluate mRNA expression levels of cyp51A and mdr1 genes in voriconazole resistant A. flavus by a Real-Time Reverse Transcriptase Polymerase Chain Reaction (RT-...

  1. Changes of Tc-99m sestamibi uptake in P-glycoprotein expressing leukaemia cells treated in vivo with antisense oligodeoxynucleotide complementary to mdr1 mRNA

    International Nuclear Information System (INIS)

    We examined the feasibility of Tc-99m sestamibi to monitor changes of mRNA expression of MDRl/P-glycoprotein (Pgp) following antisense oligodeoxynucleotide (AS-ODN) treatment in vivo. Three days after the intraperitoneal inoculation of murine leukaemia P388/R cells expressing MDR1/P-gp in CDFI mice, 15-mer phosphorothioate ASODN to the initiation codon of mouse mdr1 mRNA was administered intraperitoneally at 10 mg/kg daily for 3 or 4 days. Cells collected from ascites were suspended in medium for Tc-99m sestamibi uptake studies. To know the duration of antisense effects, cells were harvested 2 days later after the 3-day treatment. AS-ODN treatment increased Tc-99m sestamibi uptake. Effects of 3-day treatment and 4-day treatment were the same. Treatment effects were not detected when uptake was observed 2 days after 3-day treatment. Based on the results it was concluded that in vivo treatment with AS-ODN specific to the coding portion of mdr1 mRNA increased Tc-99m sestamibi uptake in leukaemia cells possessing MDR function. (author)

  2. Expression of LRP and MDR1 in locally advanced breast cancer predicts axillary node invasion at the time of rescue mastectomy after induction chemotherapy

    International Nuclear Information System (INIS)

    Axillary node status after induction chemotherapy for locally advanced breast cancer has been shown on multivariate analysis to be an independent predictor of relapse. However, it has been postulated that responders to induction chemotherapy with a clinically negative axilla could be spared the burden of lymphadenectomy, because most of them will not show histological nodal invasion. P-glycoprotein expression in the rescue mastectomy specimen has finally been identified as a significant predictor of patient survival. We studied the expression of the genes encoding multidrug resistance associated protein (MDR1) and lung cancer associated resistance protein (LRP) in formalin-fixed, paraffin-embedded tumor samples from 52 patients treated for locally advanced breast cancer by means of induction chemotherapy followed by rescue mastectomy. P-glycoprotein expression was assessed by means of immunohistochemistry before treatment in 23 cases, and by means of reverse-transcriptase-mediated polymerase chain reaction (RT-PCR) after treatment in 46 (6 failed). LRP expression was detected by means of immunohistochemistry, with the LRP-56 monoclonal antibody, in 31 cases before treatment. Immunohistochemistry for detecting the expression of c-erb-B2, p53, Ki67, estrogen receptor and progesterone receptor are routinely performed in our laboratory in every case, and the results obtained were included in the study. All patients had received between two and six cycles of standard 5-fluorouracil, doxorubicin and cyclophosphamide (FAC) chemotherapy, with two exceptions [one patient received four cycles of a docetaxel-adriamycin combination, and the other four cycles of standard cyclophosphamide-methotrexate-5-fluorouracil (CMF) polychemotherapy]. Response was assessed in accordance with the Response Evaluation Criteria In Solid Tumors (RECIST). By these, 2 patients achieved a complete clinical response, 37 a partial response, and the remaining 13 showed stable disease. This makes a

  3. GFAP、Vim、MDR-1与EGFR在颅内星形细胞肿瘤中的表达及意义%The significance of the expression of GFAP、Vim、MDR-1 and EGFR in intracranial astrocytic tumor

    Institute of Scientific and Technical Information of China (English)

    楼善贤; 王利霞; 刘庆伟

    2003-01-01

    目的探讨颅内星形细胞肿瘤的GFAP、Vim和MDR-1、EGFR的表达及意义.方法采用S-P法对101例颅内星形细胞肿瘤进行GFAP、Vim、和MDR-1、EGFR免疫组化标记,并对临床和病理资料及免疫组化结果进行统计分析.结果免疫组化标记能帮助区别星形细胞肿瘤的组织类型和分化程度.间变性星形细胞瘤和胶质母细胞瘤GFAP表达减弱,而Vim、MDR-1、EGFR的表达增强,恶性程度增加,术后生存率低(P<0.005).结论免疫组化标记对星形细胞肿瘤术后化疗方案的制定及预后估计具有重要意义.间变性和肥胖细胞性星形细胞瘤更具恶性,易复发.胶质母细胞瘤恶性程度最高,预后差.

  4. Construction of Multi-ribozyme Expression System and Its Characterization of Cleavage on the MDR1/MRP1 Double Target Substrate in vitro

    Institute of Scientific and Technical Information of China (English)

    TIAN Sheng-li; ZHENG Suo; LIU Shi-de; ZHANG Jian-hua; XU Dong-ping; OHNUMA Takao

    2009-01-01

    To improve catalytic activity of ribozyme on its substrate,the multi-ribozyme expression system was designed and constructed from 20 cis-acting hammerhead ribozymes undergoing self-cleavage with 10 trans-acting hammerhead ribozymes inserted altematively regularly and the plasmid of pGEM-MDRI/MRPI used to transcribe the M DRI/MRPI(196/210) substrate containing double target sites was also constructed by DNA recombination.Endonuclease digestion analysis and DNA sequencing indicate all the recombinant plasmids were correct.The cleavage activities were evaluated for the multi-ribozyme expression system on the MDR1/MRP1 substrate in the cell free system.The results demonstrate that the cis-acting hammerhead ribozymes in the multi-ribozyme expression system were able to cleave themselves and the 72 nt of 196Rz and the 71 nt of 210Rz trans-acting hammerhead ribozymes were liberated effectively,and the trans-acting hammerhead ribozymes released were able to act on the MDR1/MRP1 double target RNA substrate and cleave the target RNA at specific sites effectively.The multiribozyme expression system of the [Coat'A196Rz/Coat'B210Rz]5 is more significantly superior to that of the [Coat'A 196Rz/Coat'B210Rz]1 in cleavage of RNA substrate.The fractions cleaved by [Coat'A196Rz/Coat'B210Rz]5 on the MDR1/MRP1 substrate for 8 h at observed temperatures showed no marked difference.The studies of Mg2+ on cleavage efficiency indicate that cleavage reaction is dependent on Mg2+ ions concentration.The plot of Ig(kobs) vs.Igc(Mg2+) displays a linear relationship between 2.5 mmol/L and 20 mmol/L Mg2..It suggests that Mg2+ ions play a crucial role in multi-ribozyme cleavage on the substrate.

  5. Selective reversal of drug resistance in drug-resistant lung adenocarcinoma cells by tumor-specific expression of MDR1 ribozyme gene mediated by retrovirus

    Institute of Scientific and Technical Information of China (English)

    高振强; 高志萍; 刘喜富; 张涛

    1997-01-01

    According to the fact that CEA gene expressed only in lung adenocarcinoma and not in normal lung cells, a retroviral vector (pCEAMR) was constructed which carried the CEA promoter coupled to MDR1 ribozyme gene. pCEAMR was introduced into drug-resistant lung adenocarcinoma cells GAOK with CEA expression and HeLaK without CEA expression; the expression of pCEAMR and drug resistance in the infected cells were analyzed in vitro and in vivo ; pCEAMR expressed only in CEA-producing GAOK cells and not in non-CEA-producing HeLa cells. The drug resistance to doxorubicin (DOX) decreased 91.5% in the infected GAOK cells and did not change in the infected HeLa cells. In nude mice, DOX could obviously inhibit the growth of the infected GAOK tumors, and had no effect on the growth of the infected HeLa cells. These results indicated that MDR1 ribozyme gene regulated by CEA promoter expressed only in human adenocarcinoma cells and reversed their drug resistance selectively. This gene-drug therapy might serve as an effe

  6. Casein Kinase 2 (CK2)-mediated Phosphorylation of Hsp90β as a Novel Mechanism of Rifampin-induced MDR1 Expression.

    Science.gov (United States)

    Kim, So Won; Hasanuzzaman, Md; Cho, Munju; Heo, Ye Rang; Ryu, Min-Jung; Ha, Na-Young; Park, Hyun June; Park, Hyung-Yeon; Shin, Jae-Gook

    2015-07-01

    The P-glycoprotein (P-gp) encoded by the MDR1 gene is a drug-exporting transporter located in the cellular membrane. P-gp induction is regarded as one of the main mechanisms underlying drug-induced resistance. Although there is great interest in the regulation of P-gp expression, little is known about its underlying regulatory mechanisms. In this study, we demonstrate that casein kinase 2 (CK2)-mediated phosphorylation of heat shock protein 90β (Hsp90β) and subsequent stabilization of PXR is a key mechanism in the regulation of MDR1 expression. Furthermore, we show that CK2 is directly activated by rifampin. Upon exposure to rifampin, CK2 catalyzes the phosphorylation of Hsp90β at the Ser-225/254 residues. Phosphorylated Hsp90β then interacts with PXR, causing a subsequent increase in its stability, leading to the induction of P-gp expression. In addition, inhibition of CK2 and Hsp90β enhances the down-regulation of PXR and P-gp expression. The results of this study may facilitate the development of new strategies to prevent multidrug resistance and provide a plausible mechanism for acquired drug resistance by CK2-mediated regulation of P-gp expression. PMID:25995454

  7. Drug resistance to paclitaxel is not only associated with ABCB1 mRNA expression but also with drug accumulation in intracellular compartments in human lung cancer cell lines.

    Science.gov (United States)

    Shimomura, Masanori; Yaoi, Takeshi; Itoh, Kyoko; Kato, Daishiro; Terauchi, Kunihiko; Shimada, Junichi; Fushiki, Shinji

    2012-04-01

    In order to clarify the mechanisms of resistance to paclitaxel in lung cancer, three human lung cancer cell lines which exhibit different sensitivity to paclitaxel were investigated from the following viewpoints: overexpression of ATP-binding cassette, sub-family B, member 1 (ABCB1), mutations on paclitaxel binding site of β-tubulin genes, quantity of polymerized tubulin and the intracellular localization of paclitaxel. ABCB1 expression was evaluated by real-time RT-PCR. No correlations were noted between the ABCB1 expression in the sensitive and resistant cell lines at the mRNA level. No mutations on the paclitaxel binding site of the β-tubulin genes were detected in either the resistant or sensitive cells. Live cell images obtained by confocal laser microscopy revealed that the resistant cell line, RERF-LC-KJ, had more accumulation of Oregon Green® 488 conjugated paclitaxel in the lysosomal and extra-lysosomal compartments of cytoplasm than other cell lines. The results obtained in this study indicated that the changes in the subcellular localization could contribute to the production of paclitaxel resistance in lung cancer cell lines. Further studies should be conducted to elucidate the molecular mechanisms that differentiate the intracellular localization of paclitaxel. PMID:22179563

  8. The putative P-gp inhibitor telmisartan does not affect the transcellular permeability and cellular uptake of the calcium channel antagonist verapamil in the P-glycoprotein expressing cell line MDCK II MDR1

    DEFF Research Database (Denmark)

    Saaby, Lasse; Tfelt-Hansen, Peer; Brodin, Birger

    2015-01-01

    Verapamil is used in high doses for the treatment of cluster headache. Verapamil has been described as a P-glycoprotein (P-gp, ABCB1) substrate. We wished to evaluate in vitro whether co administration of a P-gp inhibitor with verapamil could be a feasible strategy for increasing CNS uptake...... of verapamil. Fluxes of radiolabelled verapamil across MDCK II MDR1 monolayers were measured in the absence and presence of the putative P-gp inhibitor telmisartan (a clinically approved drug compound). Verapamil displayed a vectorial basolateral-to-apical transepithelial efflux across the MDCK II MDR1...... monolayers with a permeability of 5.7 × 10−5 cm sec−1 compared to an apical to basolateral permeability of 1.3 × 10−5 cm sec-1. The efflux could be inhibited with the P-gp inhibitor zosuquidar. Zosuquidar (0.4 μmol/L) reduced the efflux ratio (PB-A/PA-B) for verapamil 4.6–1.6. The presence of telmisartan...

  9. JNK1/2 Activation by an Extract from the Roots of Morus alba L. Reduces the Viability of Multidrug-Resistant MCF-7/Dox Cells by Inhibiting YB-1-Dependent MDR1 Expression

    Directory of Open Access Journals (Sweden)

    Youn Kyung Choi

    2013-01-01

    Full Text Available Cancer cells acquire anticancer drug resistance during chemotherapy, which aggravates cancer disease. MDR1 encoded from multidrug resistance gene 1 mainly causes multidrug resistance phenotypes of different cancer cells. In this study, we demonstrate that JNK1/2 activation by an extract from the root of Morus alba L. (White mulberry reduces doxorubicin-resistant MCF-7/Dox cell viability by inhibiting YB-1 regulation of MDR1 gene expression. When MCF-7 or MCF-7/Dox cells, where MDR1 is highly expressed were treated with an extract from roots or leaves of Morus alba L., respectively, the root extract from the mulberry (REM but not the leaf extract (LEM reduced cell viabilities of both MCF-7 and MCF-7/Dox cells, which was enhanced by cotreatment with doxorubicin. REM but not LEM further inhibited YB-1 nuclear translocation and its regulation of MDR1 gene expression. Moreover, REM promoted phosphorylation of c-Jun NH2-terminal kinase 1/2 (JNK1/2 and JNK1/2 inhibitor, SP600125 and rescued REM inhibition of both MDR1 expression and viabilities in MCF-7/Dox cells. Consistently, overexpression of JNK1, c-Jun, or c-Fos inhibited YB-1-dependent MDR1 expression and reduced viabilities in MCF-7/Dox cells. In conclusion, our data indicate that REM-activated JNK-cJun/c-Fos pathway decreases the viability of MCF-7/Dox cells by inhibiting YB-1-dependent MDR1 gene expression. Thus, we suggest that REM may be useful for treating multidrug-resistant cancer cells.

  10. Hernandezine, a Bisbenzylisoquinoline Alkaloid with Selective Inhibitory Activity against Multidrug-Resistance-Linked ATP-Binding Cassette Drug Transporter ABCB1.

    Science.gov (United States)

    Hsiao, Sung-Han; Lu, Yu-Jen; Yang, Chun-Chiao; Tuo, Wei-Cherng; Li, Yan-Qing; Huang, Yang-Hui; Hsieh, Chia-Hung; Hung, Tai-Ho; Wu, Chung-Pu

    2016-08-26

    The overexpression of ATP-binding cassette (ABC) drug transporter ABCB1 (P-glycoprotein, MDR1) is the most studied mechanism of multidrug resistance (MDR), which remains a major obstacle in clinical cancer chemotherapy. Consequently, resensitizing MDR cancer cells by inhibiting the efflux function of ABCB1 has been considered as a potential strategy to overcome ABCB1-mediated MDR in cancer patients. However, the task of developing a suitable modulator of ABCB1 has been hindered mostly by the lack of selectivity and high intrinsic toxicity of candidate compounds. Considering the wide range of diversity and relatively nontoxic nature of natural products, developing a potential modulator of ABCB1 from natural sources is particularly valuable. Through screening of a large collection of purified bioactive natural products, hernandezine was identified as a potent and selective reversing agent for ABCB1-mediated MDR in cancer cells. Experimental data demonstrated that the bisbenzylisoquinoline alkaloid hernandezine is selective for ABCB1, effectively inhibits the transport function of ABCB1, and enhances drug-induced apoptosis in cancer cells. More importantly, hernandezine significantly resensitizes ABCB1-overexpressing cancer cells to multiple chemotherapeutic drugs at nontoxic, nanomolar concentrations. Collectively, these findings reveal that hernandezine has great potential to be further developed into a novel reversal agent for combination therapy in MDR cancer patients. PMID:27504669

  11. 愈痫灵方对KA致痫大鼠海马及颞叶皮质多药耐药基因MDR1b表达的影响%Effects of Yuxianling Decoction on the Expression of Multiple Drug Resistant Gene MDR1b in Hippocampusand Temporal Lobe Cortex of Epileptic Rats Induced by Kainic Acid

    Institute of Scientific and Technical Information of China (English)

    李振光; 宋祖丽; 王净净; 李智雄; 谢静涛; 左亚杰; 张曦; 肖瑶

    2015-01-01

    〔Abstract〕 Objective To investigate the effects of Yuxianling Decoction (YXLD) on expression of multiple drug resistant gene MDR1b in hippocampus and temporal lobe cortex of epileptic rats induced by kaicic acid (KA). Methods (1) Making models:The Hippocampus in rats located by brain stereotactic apparatus was microinjected 1μg KA (1.0 μg/μL) to kindle seizures models. The rats at above seizure behavior surpass Ⅳ level were intragastric administration interfered by sodium valproate and carbamazepine for 14 days, and rekindled 0.5 μL. The rats second attacked seizure at above Ⅳ level and with persistent state were selected.Moreover, the rats with epileptiform discharge wave were selected to be successful resistant refractory epilepsy model rats. (2) Grouping and treatment: The Successful model rats were randomly divided into YXLD group, lamotrigine control group and model group, rats were also assigned into sham operation group and normal control group, 12 rats in each group. The rats were intragastric administration interfered by the same volume of distilled water, lamotrigine and YXLD respectively for 30 days (2 mL/d). (3) Selecting and detecting specimens: The expression of MDR 1b in hippocampus area and temporal lobe cortex was detected by real-time fluorescent quantitative polymerase chain reaction (RT-PCR) method. Results Compared with sham operation control group and normal blank control group, the expression level of MDR1b in hippocampus area was increased obviously (P0.05); The MDR1b expression in hippocampus area of all model groups was higher than that in temporal lobe cortex, the differences have statistical significance (P0.05); MDR1b expression level intemporal lobe cortex between all groups have no statistical significance (P>0.05). Conclusion The expression of multiple drug resistant gene MDR1b in the hippocampus of KA epileptic rats was increased significantly than that in temporal lobe cortex. One of mechanisms of YXLD on anti

  12. 甲胎蛋白对耐药基因MDR1表达及肝癌细胞化疗敏感性的影响%Influence of alpha-fetoprotein on the expression of drug-resistance gene MDR1 and chemotherapeutic sensitivity in hepatocellular carcinoma cells

    Institute of Scientific and Technical Information of China (English)

    吴超; 杨健; 张金玲; 金涛; 何前进; 李常海

    2015-01-01

    Objective To explore the influence of alpha-fetoprotein (AFP) on the expression of drug-resistance gene MDR1 and chemotherapeutic sensitivity in hepatocellular carcinoma (HCC) cells.Methods A HCC cell line SMMC-7721/AFP, which was stably transfected with AFP gene, was established.mRNA and protein expressions of AFP and MDR1 were detected by real-time PCR and Western Blot,respectively.The sensitivity of SMMC-7721/AFP and SMMC-7721/EGFP cells with or without MDR1 silencing by siRNA to doxorubicin was tested by MTT assay.Immunohistochemistry was used to detect the expression of MDR1 genes-coded protein Pgp in 60 cases of HCC tissues, and the relationship between Pgp expression and serum AFP levels was analyzed.Results AFP mRNA and protein could be detected in SMMC-7721/AFP cells, but not in control cells, indicating that the AFP stably transfected cell line was successfully established.MDR1 mRNA and protein levels were higher in SMMC-7721/AFP cells than those in SMMC-7721/EGFP cells.MDR1 mRNA level in SMMC-7721/AFP cells was (52.7 ± 1.5) times as high as that in SMMC-7721/EGFP cells (P < 0.05).The resistance to doxorubicin was increased by (12.8 ± 1.1) times after AFP transfection (P < 0.05).The chemosensitivity to doxorubicin was increased after the expression of MDR1 was knocked down by siRNA.The expression of Pgp in HCC tissues was positively correlated with the serum AFP levels.Conclusion AFP could induce drug-resistance to doxorubicin in HCC cells by increasing the expression of MDR1.%目的 探讨甲胎蛋白(AFP)对耐药基因MDR1表达和肝癌细胞化疗敏感性的影响.方法 建立稳定表达AFP的肝癌细胞系SMMC-7721/AFP,分别通过Real-time PCR和蛋白印迹检测转染前后AFP和MDR1的表达.MTT法测定SMMC-7721/AFP和SMMC-7721/EGFP细胞对阿霉素的化疗敏感性.siRNA沉默SMMC-7721/AFP细胞中MDR1的表达,观察细胞对阿霉素化疗敏感性的变化.采用免疫组织化学染色法检测60例肝癌组织中MDR1编码蛋

  13. Downregulation of gene MDR1 by shRNA to reverse multidrug-resistance of ovarian cancer A2780 cells

    OpenAIRE

    Hongyi Zhang; Jing Wang; Kai Cai; Longwei Jiang; Dandan Zhou; Cuiping Yang,; Junsong Chen,; Dengyu Chen,; Jun Dou

    2012-01-01

    Background: To explore the effects of downregulated multidrug-resistance P-glycoprotein (MDR1/ABCB1) and reversed multidrug-resistance in human A2780 ovarian cancer cells. Materials and Methods: Three shRNAs targeting the MDR1 gene were synthesized, and cloned into plasmid pSUPER-enhanced green fluorescent protein 1 (EGFP1). The formed pSUPER-EGFP1-MDR1-shRNAs were transfected into the A2780 cells, respectively, and the quantitative reverse transcription polymerase chain reaction and west...

  14. Inhibition of mTORC2 Induces Cell-Cycle Arrest and Enhances the Cytotoxicity of Doxorubicin by Suppressing MDR1 Expression in HCC Cells

    Science.gov (United States)

    Chen, Bryan Wei; Chen, Wei; Liang, Hui; Liu, Hao; Liang, Chao; Zhi, Xiao; Hu, Li-qiang; Yu, Xia-Zhen; Wei, Tao; Ma, Tao; Xue, Fei; Zheng, Lei; Zhao, Bin; Feng, Xin-Hua; Bai, Xue-li; Liang, Ting-bo

    2016-01-01

    mTOR is aberrantly activated in hepatocellular carcinoma (HCC) and plays pivotal roles in tumorigenesis and chemoresistance. Rapamycin has been reported to exert antitumor activity in HCC and sensitizes HCC cells to cytotoxic agents. However, due to feedback activation of AKT after mTOR complex 1 (mTORC1) inhibition, simultaneous targeting of mTORC1/2 may be more effective. In this study, we examined the interaction between the dual mTORC1/2 inhibitor OSI-027 and doxorubicin in vitro and in vivo. OSI-027 was found to reduce phosphorylation of both mTORC1 and mTORC2 substrates, including 4E-BP1, p70S6K, and AKT (Ser473), and inhibit HCC cell proliferation. Similar to OSI-027 treatment, knockdown of mTORC2 induced G0–G1 phase cell-cycle arrest. In contrast, rapamycin or knockdown of mTORC1 increased phosphorylation of AKT (Ser473), yet had little antiproliferative effect. Notably, OSI-027 synergized with doxorubicin for the antiproliferative efficacy in a manner dependent of MDR1 expression in HCC cells. The synergistic antitumor effect of OSI-027 and doxorubicin was also observed in a HCC xenograft mouse model. Moreover, AKT was required for OSI-027–induced cell-cycle arrest and downregulation of MDR1. Our findings provide a rationale for dual mTORC1/mTORC2 inhibitors, such as OSI-027, as monotherapy or in combination with cytotoxic agents to treat HCC. PMID:26026051

  15. Inhibition of mTORC2 Induces Cell-Cycle Arrest and Enhances the Cytotoxicity of Doxorubicin by Suppressing MDR1 Expression in HCC Cells.

    Science.gov (United States)

    Chen, Bryan Wei; Chen, Wei; Liang, Hui; Liu, Hao; Liang, Chao; Zhi, Xiao; Hu, Li-Qiang; Yu, Xia-Zhen; Wei, Tao; Ma, Tao; Xue, Fei; Zheng, Lei; Zhao, Bin; Feng, Xin-Hua; Bai, Xue-Li; Liang, Ting-Bo

    2015-08-01

    mTOR is aberrantly activated in hepatocellular carcinoma (HCC) and plays pivotal roles in tumorigenesis and chemoresistance. Rapamycin has been reported to exert antitumor activity in HCC and sensitizes HCC cells to cytotoxic agents. However, due to feedback activation of AKT after mTOR complex 1 (mTORC1) inhibition, simultaneous targeting of mTORC1/2 may be more effective. In this study, we examined the interaction between the dual mTORC1/2 inhibitor OSI-027 and doxorubicin in vitro and in vivo. OSI-027 was found to reduce phosphorylation of both mTORC1 and mTORC2 substrates, including 4E-BP1, p70S6K, and AKT (Ser473), and inhibit HCC cell proliferation. Similar to OSI-027 treatment, knockdown of mTORC2 induced G0-G1 phase cell-cycle arrest. In contrast, rapamycin or knockdown of mTORC1 increased phosphorylation of AKT (Ser473), yet had little antiproliferative effect. Notably, OSI-027 synergized with doxorubicin for the antiproliferative efficacy in a manner dependent of MDR1 expression in HCC cells. The synergistic antitumor effect of OSI-027 and doxorubicin was also observed in a HCC xenograft mouse model. Moreover, AKT was required for OSI-027-induced cell-cycle arrest and downregulation of MDR1. Our findings provide a rationale for dual mTORC1/mTORC2 inhibitors, such as OSI-027, as monotherapy or in combination with cytotoxic agents to treat HCC. Mol Cancer Ther; 14(8); 1805-15. ©2015 AACR. PMID:26026051

  16. ABCB1 in children's brain tumours.

    Science.gov (United States)

    Coyle, Beth; Kessler, Maya; Sabnis, Durgagauri H; Kerr, Ian D

    2015-10-01

    Tumours of the central nervous system are the most common solid tumour, accounting for a quarter of the 1500 cases of childhood cancer diagnosed each year in the U.K. They are the most common cause of cancer-related death in children. Treatment consists of surgery followed by adjuvant chemotherapy and/or radiotherapy. Survival rates have generally increased, but many survivors suffer from radiotherapy-related neurocognitive and endocrine side effects as well as an increased risk of secondary cancer. Adjuvant chemotherapy is normally given in combination to circumvent chemoresistance, but several studies have demonstrated it to be ineffective in the absence of radiotherapy. The identification of children with drug-resistant disease at the outset could allow stratification of those that are potentially curable by chemotherapy alone. Ultimately, however, what is required is a means to overcome this drug resistance and restore the effectiveness of chemotherapy. Medulloblastomas and ependymomas account for over 30% of paediatric brain tumours. Advances in neurosurgery, adjuvant radiotherapy and chemotherapy have led to improvements in 5-year overall survival rates. There remain, however, significant numbers of medulloblastoma patients that have intrinsically drug-resistant tumours and/or present with disseminated disease. Local relapse in ependymoma is also common and has an extremely poor prognosis with only 25% of children surviving first relapse. Each of these is consistent with the acquisition of drug and radiotherapy resistance. Since the majority of chemotherapy drugs currently used to treat these patients are transport substrates for ATP-binding cassette sub-family B member 1 (ABCB1) we will address the hypothesis that ABCB1 expression underlies this drug resistance. PMID:26517917

  17. Purvalanol A, olomoucine II and roscovitine inhibit ABCB1 transporter and synergistically potentiate cytotoxic effects of daunorubicin in vitro.

    Directory of Open Access Journals (Sweden)

    Daniela Cihalova

    Full Text Available Cyclin-dependent kinase inhibitors (CDKi have high potential applicability in anticancer therapy, but various aspects of their pharmacokinetics, especially their interactions with drug efflux transporters, have not yet been evaluated in detail. Thus, we investigated interactions of five CDKi (purvalanol A, olomoucine II, roscovitine, flavopiridol and SNS-032 with the ABCB1 transporter. Four of the compounds inhibited efflux of two ABCB1 substrates, Hoechst 33342 and daunorubicin, in MDCKII-ABCB1 cells: Olomoucine II most strongly, followed by roscovitine, purvalanol A, and flavopiridol. SNS-032 inhibited ABCB1-mediated efflux of Hoechst 33342 but not daunorubicin. In addition, purvalanol A, SNS-032 and flavopiridol lowered the stimulated ATPase activity in ABCB1 membrane preparations, while olomoucine II and roscovitine not only inhibited the stimulated ATPase but also significantly activated the basal ABCB1 ATPase, suggesting that these two CDKi are ABCB1 substrates. We further revealed that the strongest ABCB1 inhibitors (purvalanol A, olomoucine II and roscovitine synergistically potentiate the antiproliferative effect of daunorubicin, a commonly used anticancer drug and ABCB1 substrate, in MDCKII-ABCB1 cells as well as in human carcinoma HCT-8 and HepG2 cells. We suggest that this pronounced synergism is at least partly caused by (i CDKi-mediated inhibition of ABCB1 transporter leading to increased intracellular retention of daunorubicin and (ii native cytotoxic activity of the CDKi. Our results indicate that co-administration of the tested CDKi with anticancer drugs that are ABCB1 substrates may allow significant dose reduction in the treatment of ABCB1-expressing tumors.

  18. Epigenetic modulation of the drug resistance genes MGMT, ABCB1 and ABCG2 in glioblastoma multiforme

    Science.gov (United States)

    2013-01-01

    Background Resistance of the highly aggressive glioblastoma multiforme (GBM) to drug therapy is a major clinical problem resulting in a poor patient’s prognosis. Beside promoter methylation of the O 6 -methylguanine-DNA-methyltransferase (MGMT) gene the efflux transporters ABCB1 and ABCG2 have been suggested as pivotal factors contributing to drug resistance, but the methylation of ABCB1 and ABCG2 has not been assessed before in GBM. Methods Therefore, we evaluated the proportion and prognostic significance of promoter methylation of MGMT, ABCB1 and ABCG2 in 64 GBM patient samples using pyrosequencing technology. Further, the single nucleotide polymorphisms MGMT C-56 T (rs16906252), ABCB1 C3435T (rs1045642) and ABCG2 C421A (rs2231142) were determined using the restriction fragment length polymorphism method (RFLP). To study a correlation between promoter methylation and gene expression, we analyzed MGMT, ABCB1 and ABCG2 expression in 20 glioblastoma and 7 non-neoplastic brain samples. Results Despite a significantly increased MGMT and ABCB1 promoter methylation in GBM tissue, multivariate regression analysis revealed no significant association between overall survival of glioblastoma patients and MGMT or ABCB1 promoter methylation. However, a significant negative correlation between promoter methylation and expression could be identified for MGMT but not for ABCB1 and ABCG2. Furthermore, MGMT promoter methylation was significantly associated with the genotypes of the MGMT C-56 T polymorphism showing a higher methylation level in the T allele bearing GBM. Conclusions In summary, the data of this study confirm the previous published relation of MGMT promoter methylation and gene expression, but argue for no pivotal role of MGMT, ABCB1 and ABCG2 promoter methylation in GBM patients’ survival. PMID:24380367

  19. Targeting ABCB1-mediated tumor multidrug resistance by CRISPR/Cas9-based genome editing

    Science.gov (United States)

    Yang, Yang; Qiu, Jian-Ge; Li, Yong; Di, Jin-Ming; Zhang, Wen-Ji; Jiang, Qi-Wei; Zheng, Di-Wei; Chen, Yao; Wei, Meng-Ning; Huang, Jia-Rong; Wang, Kun; Shi, Zhi

    2016-01-01

    The RNA-guided clustered regularly interspaced short palindromic (CRISPR) in combination with a CRISPR-associated nuclease 9 (Cas9) nuclease system is a new rapid and precise technology for genome editing. In the present study, we applied the CRISPR/Cas9 system to target ABCB1 (also named MDR1) gene which encodes a 170 kDa transmembrane glycoprotein (P-glycoprotein/P-gp) transporting multiple types of chemotherapeutic drugs including taxanes, epipodophyllotoxins, vinca alkaloids and anthracyclines out of cells to contribute multidrug resistance (MDR) in cancer cells. Our data showed that knockout of ABCB1 by CRISPR/Cas9 system was succesfully archieved with two target sgRNAs in two MDR cancer cells due to the alteration of genome sequences. Knockout of ABCB1 by CRISPR/Cas9 system significantly enhances the sensitivity of ABCB1 substrate chemotherapeutic agents and the intracellular accumulation of rhodamine 123 and doxorubicin in MDR cancer cells. Although now there are lots of limitations to the application of CRISPR/Cas9 for editing cancer genes in human patients, our study provides valuable clues for the use of the CRISPR/Cas9 technology in the investigation and conquest of cancer MDR. PMID:27725879

  20. Cetuximab enhanced the efficacy of chemotherapeutic agent in ABCB1/P-glycoprotein-overexpressing cancer cells.

    Science.gov (United States)

    Wang, Fang; Chen, Yifan; Huang, Lihua; Liu, Tao; Huang, Yue; Zhao, Jianming; Wang, Xiaokun; Yang, Ke; Ma, Shaolin; Huang, Liyan; To, Kenneth Kin Wah; Gu, Yong; Fu, Liwu

    2015-12-01

    The overexpression of ATP-binding cassette (ABC) transporters is closely associated with the development of multidrug resistance (MDR) in certain types of cancer, which represents a formidable obstacle to the successful cancer chemotherapy. Here, we investigated that cetuximab, an EGFR monoclonal antibody, reversed the chemoresistance mediated by ABCB1, ABCG2 or ABCC1. Our results showed that cetuximab significantly enhanced the cytotoxicity of ABCB1 substrate agent in ABCB1-overexpressing MDR cells but had no effect in their parental drug sensitive cells and ABCC1, ABCG2 overexpressing cells. Furthermore, cetuximab markedly increased intracellular accumulation of doxorubicin (DOX) and rhodamine 123 (Rho 123) in ABCB1-overexpressing MDR cancer cells in a concentration-dependent manner. Cetuximab stimulated the ATPase activity but did not alter the expression level of ABCB1 or block phosphorylation of AKT and ERK. Interestingly, cetuximab decreased the cell membrane fluidity which was known to decrease the function of ABCB1. Our findings advocate further clinical investigation of combination chemotherapy of cetuximab and conventional chemotherapeutic drugs in ABCB1 overexpressing cancer patients.

  1. Contribution of the murine mdr1a P-glycoprotein to hepatobiliary and intestinal elimination of cationic drugs as measured in mice with an mdr1a gene disruption

    NARCIS (Netherlands)

    Smit, J.W; Schinkel, A.H; Muller, M; Weert, B; Meijer, D.K F

    1998-01-01

    In the mouse, both the mdr1a and the mdr1b gene encode drug-transporting P-glycoproteins, The mdr1a P-glycoprotein is expressed in epithelial cells of, among others, the liver and the intestine, Furthermore, the mdr1b gene product is found in the liver but is not detectable in the intestine, To esta

  2. Die Bedeutung der ABC-Transportsysteme ABCB1 und Abcb11 in der Arzneimitteltherapie und bei cholestatischen Lebererkrankungen

    OpenAIRE

    Gerloff, Thomas

    2004-01-01

    ABC-Transmembrantransporter sind an der Aufnahme, Verteilung und Ausscheidung vieler Arznei- und Fremdstoffe beteiligt. Sie spielen eine Schlüsselrolle in der Pharmakokinetik und in der Ausscheidung toxischer endogener oder exogener Substanzen. Das Ziel der hier präsentierten Untersuchungen war deshalb, den Einfluss genetischer Polymorphismen des bekanntesten Vertreters dieser Proteinfamilie, MDR1 (ABCB1) zu untersuchen. Darüberhinaus sollte der ebenfalls zur ABC-Transporterfamilie gehörende ...

  3. Dual regulation of P-glycoprotein expression by Trichostatin A in cancer cell lines

    Directory of Open Access Journals (Sweden)

    Balaguer Trinidad

    2012-07-01

    Full Text Available Abstract Background It has been reported that the histone deacetylase inhibitor (iHDAc trichostatin A (TSA induces an increase in MDR1 gene transcription (ABCB1. This result would compromise the use of iHDACs in combination with other cytotoxic agents that are substrates of P-glycoprotein (Pgp. It has also been reported the use of alternative promoters by the ABCB1 gene and the existence of a translational control of Pgp protein. Finally, the ABCB1 gene is located in a genetic locus with the nested gene RUNDC3B in the complementary DNA strand, raising the possibility that RUNDC3B expression could interfere with ABCB1 alternative promoter regulation. Methods A combination of RT-PCR, real time RT-PCR, Western blot and drug accumulation assays by flow cytometry has been used in this study. Results The iHDACs-induced increase in MDR1 mRNA levels is not followed by a subsequent increase in Pgp protein levels or activity in several pancreatic and colon carcinoma cell lines, suggesting a translational control of Pgp in these cell lines. In addition, the MDR1 mRNA produced in these cell lines is shorter in its 5′ end that the Pgp mRNA produced in cell lines expressing Pgp protein. The different size of the Pgp mRNA is due to the use of alternative promoters. We also demonstrate that these promoters are differentially regulated by TSA. The translational blockade of Pgp mRNA in the pancreatic carcinoma cell lines could be related to alterations in the 5′ end of the MDR1 mRNA in the Pgp protein expressing cell lines. In addition, we demonstrate that the ABCB1 nested gene RUNDC3B expression although upregulated by TSA is independent of the ABCB1 alternative promoter used. Conclusions The results show that the increase in MDR1 mRNA expression after iHDACs treatment is clinically irrelevant since this mRNA does not render an active Pgp protein, at least in colon and pancreatic cancer cell lines. Furthermore, we demonstrate that TSA in fact, regulates

  4. Expression of a full-length cDNA for the human "MDR1" gene confers resistance to colchicine, doxorubicin, and vinblastine.

    OpenAIRE

    Ueda, K; Cardarelli, C; Gottesman, M M; Pastan, I

    1987-01-01

    Intrinsic and acquired multidrug resistance (MDR) is an important problem in cancer therapy. MDR in human KB carcinoma cells selected for resistance to colchicine, vinblastine, or doxorubicin (former generic name adriamycin) is associated with overexpression of the "MDR1" gene, which encodes P-glycoprotein. We previously have isolated an overlapping set of cDNA clones for the human MDR1 gene from multidrug-resistant KB cells. Here we report the construction of a full-length cDNA for the human...

  5. Changes in the expression of miR-381 and miR-495 are inversely associated with the expression of the MDR1 gene and development of multi-drug resistance.

    Directory of Open Access Journals (Sweden)

    Yan Xu

    Full Text Available Multidrug resistance (MDR frequently develops in cancer patients exposed to chemotherapeutic agents and is usually brought about by over-expression of P-glycoprotein (P-gp which acts as a drug efflux pump to reduce the intracellular concentration of the drug(s. Thus, inhibiting P-gp expression might assist in overcoming MDR in cancer chemotherapy. MiRNAome profiling using next-generation sequencing identified differentially expressed microRNAs (miRs between parental K562 cells and MDR K562 cells (K562/ADM induced by adriamycin treatment. Two miRs, miR-381 and miR-495, that were strongly down-regulated in K562/ADM cells, are validated to target the 3'-UTR of the MDR1 gene. These miRs are located within a miR cluster located at chromosome region 14q32.31, and all miRs in this cluster appear to be down-regulated in K562/ADM cells. Functional analysis indicated that restoring expression of miR-381 or miR-495 in K562/ADM cells was correlated with reduced expression of the MDR1 gene and its protein product, P-gp, and increased drug uptake by the cells. Thus, we have demonstrated that changing the levels of certain miR species modulates the MDR phenotype in leukemia cells, and propose further exploration of the use of miR-based therapies to overcome MDR.

  6. ATP-binding cassette subfamily B member 1 (ABCB1) and subfamily C member 10 (ABCC10) are not primary resistance factors for cabazitaxel

    Institute of Scientific and Technical Information of China (English)

    Rishil J Kathawala; Yi-Jun Wang; Suneet Shukla; Yun-Kai Zhang; Saeed Alqahtani; Amal Kaddoumi; Suresh V Ambudkar; Charles R Ashby Jr; Zhe-Sheng Chen

    2015-01-01

    Introduction:ATP-binding cassette subfamily B member 1 (ABCB1) and subfamily C member 10 (ABCC10) proteins are efflux transporters that couple the energy derived from ATP hydrolysis to the translocation of toxic substances and chemotherapeutic drugs out of cells. Cabazitaxel is a novel taxane that differs from paclitaxel by its lower affinity for ATP-binding cassette (ABC) transporters. Methods:We determined the effects of cabazitaxel, a novel tubulin-binding taxane, and paclitaxel on paclitaxel-resistant, ABCB1-overexpressing KB-C2 and LLC-MDR1-WT cells and paclitaxel-resistant, ABCC10-overexpressing HEK293/ABCC10 cells by calculating the degree of drug resistance and measuring ATPase activity of the ABCB1 transporter. Results:Decreased resistance to cabazitaxel compared with paclitaxel was observed in KB-C2, LLC-MDR1-WT, and HEK293/ABCC10 cells. Moreover, cabazitaxel had low efficacy, whereas paclitaxel had high efficacy in stimulating the ATPase activity of ABCB1, indicating a direct interaction of both drugs with the transporter. Conclusion:ABCB1 and ABCC10 are not primary resistance factors for cabazitaxel compared with paclitaxel, suggesting that cabazitaxel may have a low affinity for these efflux transporters.

  7. Saracatinib (AZD0530) is a potent modulator of ABCB1-mediated multidrug resistance in vitro and in vivo.

    Science.gov (United States)

    Liu, Ke-Jun; He, Jie-Hua; Su, Xiao-Dong; Sim, Hong-May; Xie, Jing-Dun; Chen, Xing-Gui; Wang, Fang; Liang, Yong-Ju; Singh, Satyakam; Sodani, Kamlesh; Talele, Tanaji T; Ambudkar, Suresh V; Chen, Zhe-Sheng; Wu, Hai-Ying; Fu, Li-Wu

    2013-01-01

    Saracatinib, a highly selective, dual Src/Abl kinase inhibitor, is currently in a Phase II clinical trial for the treatment of ovarian cancer. In our study, we investigated the effect of saracatinib on the reversal of multidrug resistance (MDR) induced by ATP-binding cassette (ABC) transporters in vitro and in vivo. Our results showed that saracatinib significantly enhanced the cytotoxicity of ABCB1 substrate drugs in ABCB1 overexpressing HeLa/v200, MCF-7/adr and HEK293/ABCB1 cells, an effect that was stronger than that of gefitinib, whereas it had no effect on the cytotoxicity of the substrates in ABCC1 overexpressing HL-60/adr cells and its parental sensitive cells. Additionally, saracatinib significantly increased the doxorubicin (Dox) and Rho 123 accumulation in HeLa/v200 and MCF-7/adr cells, whereas it had no effect on HeLa and MCF-7 cells. Furthermore, saracatinib stimulated the ATPase activity and inhibited photolabeling of ABCB1 with [(125)I]-iodoarylazidoprazosin in a concentration-dependent manner. In addition, the homology modeling predicted the binding conformation of saracatinib within the large hydrophobic drug-binding cavity of human ABCB1. However, neither the expression level of ABCB1 nor the phosphorylation level of Akt was altered at the reversal concentrations of saracatinib. Importantly, saracatinib significantly enhanced the effect of paclitaxel against ABCB1-overexpressing HeLa/v200 cancer cell xenografts in nude mice. In conclusion, saracatinib reverses ABCB1-mediated MDR in vitro and in vivo by directly inhibiting ABCB1 transport function, without altering ABCB1 expression or AKT phosphorylation. These findings may be helpful to attenuate the effect of MDR by combining saracatinib with other chemotherapeutic drugs in the clinic. PMID:22623106

  8. The effect of ABCB1 polymorphisms on the outcome of breast cancer treatment

    Directory of Open Access Journals (Sweden)

    Tulsyan S

    2016-04-01

    Full Text Available Sonam Tulsyan,1 Rama Devi Mittal,2 Balraj Mittal1 1Department of Genetics, 2Department of Urology and Renal Transplant, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, IndiaAbstract: The ABCB1 gene encodes a permeability glycoprotein, which is one of the most extensively studied human adenosine-triphosphate (ATP-dependent efflux transporters. Permeability glycoprotein is expressed in the apical membranes of tissues such as intestine, liver, blood–brain barrier, kidney, placenta, and testis and contributes to intracellular drug disposition. It is also highly expressed in tumor cells conferring drug resistance, which is one of the major problems in the efficacy of cancer chemotherapy treatment. ABCB1 is highly polymorphic, and three well-known single-nucleotide polymorphisms such as 1236C>T, 2677G>T/A, and 3435C>T have been found to be associated with altered messenger RNA levels, protein folding, and drug pharmacokinetics. Many association studies and meta-analyses have demonstrated the clinical impact of ABCB1 polymorphisms in breast cancer treatment outcomes with respect to therapeutic response, chemotoxicity, and overall survival. Therefore, the aim of this review was to evaluate the effects of ABCB1 polymorphisms on the outcome of breast cancer treatment which, in future, would be important for tailoring individualized anticancer therapy.Keywords: ABCB1, P-glycoprotein, polymorphisms, breast cancer treatment, chemotherapy, response, drug resistance

  9. Regulation of ABCB1/PGP1-catalysed auxin transport by linker phosphorylation

    DEFF Research Database (Denmark)

    Henrichs, Sina; Wang, Bangjun; Fukao, Yoichiro;

    2012-01-01

    Polar transport of the plant hormone auxin is controlled by PIN-and ABCB/PGP-efflux catalysts. PIN polarity is regulated by the AGC protein kinase, PINOID (PID), while ABCB activity was shown to be dependent on interaction with the FKBP42, TWISTED DWARF1 (TWD1). Using co-immunoprecipitation (co......-IP) and shotgun LC-MS/MS analysis, we identified PID as a valid partner in the interaction with TWD1. In-vitro and yeast expression analyses indicated that PID specifically modulates ABCB1-mediated auxin efflux in an action that is dependent on its kinase activity and that is reverted by quercetin binding...... and thus inhibition of PID autophosphorylation. Triple ABCB1/PID/TWD1 co-transfection in tobacco revealed that PID enhances ABCB1-mediated auxin efflux but blocks ABCB1 in the presence of TWD1. Phospho-proteomic analyses identified S634 as a key residue of the regulatory ABCB1 linker and a very likely...

  10. MDR1 mediated chemoresistance: BMI1 and TIP60 in action.

    Science.gov (United States)

    Banerjee Mustafi, Soumyajit; Chakraborty, Prabir Kumar; Naz, Sarwat; Dwivedi, Shailendra Kumar Dhar; Street, Mark; Basak, Rumki; Yang, Da; Ding, Kai; Mukherjee, Priyabrata; Bhattacharya, Resham

    2016-08-01

    Chemotherapy-induced emergence of drug resistant cells is frequently observed and is exemplified by the expression of family of drug resistance proteins including, multidrug resistance protein 1 (MDR1). However, a concise mechanism for chemotherapy-induced MDR1 expression is unclear. Mechanistically, mutational selection, epigenetic alteration, activation of the Wnt pathway or impaired p53 function have been implicated. The present study describes that the surviving fraction of cisplatin resistant cells co- upregulate MDR1, BMI1 and acetyl transferase activity of TIP60. Using complementary gain and loss of function approaches, we demonstrate that the expression of MDR1 is positively regulated by BMI1, a stem-cell factor classically known as a transcriptional repressor. Our study establishes a functional interaction between TIP60 and BMI-1 resulting in upregulation of MDR1 expression. Chromatin immunoprecipitation (ChIP) assays further establish that the proximal MDR1 promoter responds to cisplatin in a BMI1 dependent manner. BMI1 interacts with a cluster of E-box elements on the MDR1 promoter and recruits TIP60 resulting in acetylation of histone H2A and H3. Collectively, our data establish a hitherto unknown liaison among MDR1, BMI1 and TIP60 and provide mechanistic insights into cisplatin-induced MDR1 expression resulting in acquired cross-resistance against paclitaxel, doxorubicin and likely other drugs. In conclusion, our results advocate utilizing anti-BMI1 strategies to alleviate acquired resistance to chemotherapy. PMID:27295567

  11. Identification of multi-drug resistance gene (MDR1 in equine ileum

    Directory of Open Access Journals (Sweden)

    Natalini Cláudio Corrêa

    2006-01-01

    Full Text Available P-glycoprotein (P-gp is a membrane transporter encoded in the Multi-drug Resistance (MDR1 gene expressed in several normal tissues and over expressed in tumor cells. P-gp was already identified in different species but not yet in equine. MDR1 gene and P-gp are able to interfere with bioavailability and disposition of several drugs, altering pharmacokinetic and pharmacodinamic of drugs. The presence of the MDR1 and P-gp in the central nervous system blocks the entry of certain drugs in this tissue and reduces drug absorption and enhances drug elimination when P-gp and MDR1 are presented in the gastrointestinal tract. This study showed that the MDR1 gene is present in equine ileum. Future studies on the impact of the P-glycoprotein encoded gene MDR1 on drugs pharmacologic effects in horses are granted.

  12. Human-Mouse Chimeras with Normal Expression and Function Reveal That Major Domain Swapping Is Tolerated by P-Glycoprotein (ABCB1).

    Science.gov (United States)

    Pluchino, Kristen M; Hall, Matthew D; Moen, Janna K; Chufan, Eduardo E; Fetsch, Patricia A; Shukla, Suneet; Gill, Deborah R; Hyde, Stephen C; Xia, Di; Ambudkar, Suresh V; Gottesman, Michael M

    2016-02-23

    The efflux transporter P-glycoprotein (P-gp) plays a vital role in the transport of molecules across cell membranes and has been shown to interact with a panoply of functionally and structurally unrelated compounds. How human P-gp interacts with this large number of drugs has not been well understood, although structural flexibility has been implicated. To gain insight into this transporter's broad substrate specificity and to assess its ability to accommodate a variety of molecular and structural changes, we generated human-mouse P-gp chimeras by the exchange of homologous transmembrane and nucleotide-binding domains. High-level expression of these chimeras by BacMam- and baculovirus-mediated transduction in mammalian (HeLa) and insect cells, respectively, was achieved. There were no detectable differences between wild-type and chimeric P-gp in terms of cell surface expression, ability to efflux the P-gp substrates rhodamine 123, calcein-AM, and JC-1, or to be inhibited by the substrate cyclosporine A and the inhibitors tariquidar and elacridar. Additionally, expression of chimeric P-gp was able to confer a paclitaxel-resistant phenotype to HeLa cells characteristic of P-gp-mediated drug resistance. P-gp ATPase assays and photo-cross-linking with [(125)I]iodoarylazidoprazosin confirmed that transport and biochemical properties of P-gp chimeras were similar to those of wild-type P-gp, although differences in drug binding were detected when human and mouse transmembrane domains were combined. Overall, chimeras with one or two mouse P-gp domains were deemed functionally equivalent to human wild-type P-gp, demonstrating the ability of human P-gp to tolerate major structural changes.

  13. Association of ABCB1 genetic variants with renal function in Africans and in Caucasians

    Directory of Open Access Journals (Sweden)

    Elston Robert C

    2008-06-01

    Full Text Available Abstract Background The P-glycoprotein, encoded by the ABCB1 gene, is expressed in human endothelial and mesangial cells, which contribute to control renal plasma flow and glomerular filtration rate. We investigated the association of ABCB1 variants with renal function in African and Caucasian subjects. Methods In Africans (290 subjects from 62 pedigrees, we genotyped the 2677G>T and 3435 C>T ABCB1 polymorphisms. Glomerular filtration rate (GFR was measured using inulin clearance and effective renal plasma flow (ERPF using para-aminohippurate clearance. In Caucasians (5382 unrelated subjects, we analyzed 30 SNPs located within and around ABCB1, using data from the Affymetrix 500 K chip. GFR was estimated using the simplified Modification of the Diet in Renal Disease (MDRD and Cockcroft-Gault equations. Results In Africans, compared to the reference genotype (GG or CC, each copy of the 2677T and 3435T allele was associated, respectively, with: GFR higher by 10.6 ± 2.9 (P P = 0.06 mL/min; ERPF higher by 47.5 ± 11.6 (P P = 0.007 mL/min; and renal resistances lower by 0.016 ± 0.004 (P P = 0.004 mm Hg/mL/min. In Caucasians, we identified 3 polymorphisms in the ABCB1 gene that were strongly associated with all estimates of GFR (smallest P value = 0.0006, overall P = 0.014 after multiple testing correction. Conclusion Variants of the ABCB1 gene were associated with renal function in both Africans and Caucasians and may therefore confer susceptibility to nephropathy in humans. If confirmed in other studies, these results point toward a new candidate gene for nephropathy in humans.

  14. The multidrug resistance 1 (MDR1) gene polymorphism G-rs3789243-A is not associated with disease susceptibility in Norwegian patients with colorectal adenoma and colorectal cancer; a case control study

    DEFF Research Database (Denmark)

    Andersen, V.; Agerstjerne, L.; Jensen, D.;

    2009-01-01

    Background: Smoking, dietary factors, and alcohol consumption are known life style factors contributing to gastrointestinal carcinogenesis. Genetic variations in carcinogen handling may affect cancer risk. The multidrug resistance 1(MDR1/ABCB1) gene encodes the transport protein P-glycoprotein (a...

  15. Quantitative Analysis of mdr-1 Gene Expression in Kidney Carcinoma and Its Clinical Application%应用RT-PCR方法定量分析肾癌患者多药耐药基因表达水平及其临床意义

    Institute of Scientific and Technical Information of China (English)

    庄建平; 周先举; 卢建林; 樊峰; 钱润卿

    2001-01-01

    目的 探讨肾癌患者多药耐药与组织学分级和临床病理学分期之间的关系。方法 采用逆转录-聚合酶链反应(RT-PCR)方法定量检测36例肾癌和15例正常肾组织的mdr-1表达水平。结果 肾癌的mdr-1表达水平与肾癌的组织分级有相关性,而与临床病理分期无关。结论 临床检测肾癌患者mdr-1基因的表达,可以预测患者对化疗的敏感性,为临床选 用化疗药物提供依据。%Purpose To investigate the relationship between multidrug resistance of kidney carcinoma,and histological differentiation and clinicopathological staging.Methods The expression of multidrug resistance gene mdr-1 was detected in 36 kidney carcinoma samples and 15 normal kidneys with RT-PCR(reverse transcription polymerase chain reaction).Results The level of mdr-1 gene expression in kidney carcinoma appears to be correlative with the degree of histological differentiation,but not with the clinicopathological staging.The difference of the level of mdr-1 gene expression between kidney carcinoma and normal kidney tissue is very distint.Conclusion Detection of the mdr-1 gene expression in kidney carcinoma may predict the patients' sensitivity to chemotherapy and provide a basis for clinical selection of chemotheraputic drugs.

  16. The prevalence of ABCB1:c.227_230delATAG mutation in affected dog breeds from European countries.

    Science.gov (United States)

    Firdova, Zuzana; Turnova, Evelina; Bielikova, Marcela; Turna, Jan; Dudas, Andrej

    2016-06-01

    Deletion of 4-base pairs in the canine ABCB1 (MDR1) gene, responsible for encoding P-glycoprotein, leads to nonsense frame-shift mutation, which causes hypersensitivity to macrocyclic lactones drugs (e.g. ivermectin). To date, at least 12 purebred dog breeds have been found to be affected by this mutation. The aim of this study was to update information about the prevalence of ABCB1 mutation (c.227_230delATAG) in predisposed breeds in multiple European countries. This large scale survey also includes countries which were not involved in previous studies. The samples were collected in the period from 2012 to 2014. The overview is based on genotyping data of 4729 individuals. The observed mutant allele frequencies were 58.5% (Smooth Collie), 48.3% (Rough Collie), 35% (Australian Shepherd), 30.3% (Shetland Sheepdog), 28.1% (Silken Windhound), 26.1% (Miniature Australian Shepherd), 24.3% (Longhaired Whippet), 16.2% (White Swiss Shepherd) and 0% (Border Collie). The possible presence of an ABCB1 mutant allele in Akita-Inu breed has been investigated with negative results. This information could be helpful for breeders in optimization of their breeding strategy and for veterinarians when prescribing drug therapy for dogs of predisposed breeds. PMID:27234542

  17. MODULATION OF MDR-1 GENE IN HUMAN BREAST CANCER CELLS BY SODIUM BUTYRATE AND DMSO

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective: To analyze the regulation effect of MDR-1 gene inhuman breast cancer cell by the differentiating agents, sodium butyrate and dimethyl sulfoxide. Methods: 1. A sensitive assay, RT-PCR, was used to measure the mRNA level before and after the treatment of sodium butyrate, DMSO, using b -actin as control; 2. Evaluated the effect of sodium butyrate, DMSO on MDR-1 gene expression of human breast cancer at the protein level by immunoflow cytometry; 3. P-glycoprotein function was examined after accumulation of the fluorescent drug, Phodamine-123, by flow cytometry; 4. Chemosensitivity to doxorubicin was analyzed using the MTT assay. Results: Sodium butyrate and DMSO were found to increase the MDR characteristics on MDR-1 gene, MDR-1 expression levels, P-glycoprotein function and chemosensitivity to doxorubicin. Conclusion: sodium butyrate, DMSO can modulate the MDR-1 gene at gene level, protein level, protein function level and cell level.

  18. Ferulic acid reverses ABCB1-mediated paclitaxel resistance in MDR cell lines.

    Science.gov (United States)

    Muthusamy, Ganesan; Balupillai, Agilan; Ramasamy, Karthikeyan; Shanmugam, Mohana; Gunaseelan, Srithar; Mary, Beaulah; Prasad, N Rajendra

    2016-09-01

    Multidrug resistance (MDR) remains a major obstacle in cancer chemotherapy. The use of the dietary phytochemicals as chemosensitizing agents to enhance the efficacy of conventional cytostatic drugs has recently gained the attention as a plausible approach for overcoming the drug resistance. The aim of this study was to investigate whether a naturally occurring diet-based phenolic acid, ferulic acid, could sensitize paclitaxel efficacy in ABCB1 overexpressing (P-glycoprotein) colchicine selected KB Ch(R)8-5 cell line. In vitro drug efflux assays demonstrated that ferulic acid inhibits P-glycoprotein transport function in drug resistant KB Ch(R)8-5 cell lines. However, ferulic acid significantly downregulates ABCB1 expression in a concentration dependent manner. Cytotoxicity assay reveals that ferulic acid decreased paclitaxel resistance in KBCh(R)8-5 and HEK293/ABCB1 cells, which indicates its chemosensitizing potential. Clonogenic cell survival assay and apoptotic morphological staining further confirm the chemosensitizing potential of ferulic acid in drug resistant KB Ch(R)8-5 cell lines. Ferulic acid treatment enhances paclitaxel mediated cell cycle arrest and upregulates paclitaxel-induced apoptotic signaling in KB resistant cells. Hence, it has been concluded that downregulation of ABCB1 and subsequent induction of paclitaxel-mediated cell cycle arrest and apoptotic signaling may be the cause for the chemosensitizing potential of ferulic acid in P-gp overexpressing cell lines. PMID:27262378

  19. Establishment of hepatocellular carcinoma multidrug resistant monoclone cell line HepG2/mdr1

    Institute of Scientific and Technical Information of China (English)

    CHEN Yong-bing; XIE Jian-guo; YANG Jia-yin; YAN Lü-nan; YAN Mao-lin; GONG Jian-ping; XIA Ren-pin; LIU Li-xin; LI Ning; LU Shi-chun; ZHANG Jing-guang; ZENG Dao-bing

    2007-01-01

    Background The multidrug resistance (MDR) associated with the expression of the mdr1 gene and its product P-glycoprotein is a major factor in the prognosis of hepatocellular carcinoma cell (HCC) patients treated with chemotherapy. Our study was to establish a stable HCC MDR cell line where a de novo acquisition of multidrug resistance specifically related to overexpression of a transgenic mdr1.Methods The 4.5-kb mdr1 cDNA obtained from the plasmid pHaMDR1-1 was cloned into the PCI-neo mammalian expression vector, later was transferred by liposome to human hepatocarcinoma cell line HepG2. Then the transfected HepG2 cells resisting G418 were clustered and cultured and the specific fragment of mdr1 cDNA, mRNA and the P-glycoprotein (Pgp) in these HepG2 cells were detected by PCR, RT-PCR and flow cytometry, respectively. The accumulation of the daunorubicin was determinated by flow cytometry simultaneously. The nude mice model of grafting tumour was established by injecting subcutaneously HepG2/mdr1 cells in the right axilla. When the tumour diameter reached 5 mm, adriamycin was injected into peritoneal cavity. The size and growth inhibition of tumour were evaluated.Results The mdr1 expression vector was constructed successfully and the MDR HCC line HepG2/mdr1 developed.The PCR analysis showed that the specific fragment of mdr1 cDNA in HepG2/mdr1 cells, but not in the control group HepG2 cells. Furthermore, the content of the specific fragment of mdr1 mRNA and Pgp expression in HepG2/mdr1 cells were (59.7±7.9)% and (12.28±2.09)%, respectively, compared with (16.9±3.2)% and (3.07±1.06)% in HepG2 cells.In the nude mice HCC model, the tumour genes of both groups were identified. After ADM therapy, the mean size of HepG2 cell tumours was significantly smaller than HepG2/mdr1 cell tumours.Conclusion The approach using the transfer of mdr1 cDNA may be applicable to the development of MDR hepatocarcinoma cell line, whose MDR mechanism is known. This would provide the

  20. The effect of combination therapy with doxorubicin and I-131 in multidrug resistance (MDR) gene expressing cancer cells by transduced shRNA for mdr1 mRNA and sodium Iodine symporter (NIS) genes

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Sohn Joo; Lee, Yong Jin; Lee, You La; Lee, Sang Woo; Yoo, Jeong Soo; Ahn, Byeong Cheol; Lee, Jae Tae [School of Medicine, Kyungpook National University, Daegu (Korea, Republic of)

    2007-07-01

    Transduction of shMDR for mdr1 gene and NIS gene into MDR cancer cells expressing MDR can improve therapeutic effect of anticancer treatment. We have established stable cell lines expressing both shMDR and NIS gene using mammalian expression vector from human colon cancer cells having MDR characteristics. In this study, we have evaluated effects of combined therapy with doxorubicin and I-131 in xenograft model of MDR human colon cancer cells transduced with shMDR and NIS genes. We prepared adenoviruses containing shMDR (Ad-shMDR) or NIS (Ad-NIS) gene and finally established stable cell lines expressing both shMDR and NIS gene. Two days after transfection, inhibition of P-gp function by shMDR was assessed by a change of Tc-99m MIBI uptake, and functional activity of induced NIS expression was also assessed by a change of I-125 uptake. Doxorubicin and I-131 cytotoxicity was measured in Ad-shMDR transfected or non-transfected cell lines. Tc-99m MlBl and I-131 images was obtained effect in Ad-shMDR/NIS-cotransfected tumor xenograft. Dual therapy using doxorubicin and I-131 was measured effect in injected tumor xenograft by shMDR and NIS gene expressing stable cells. After transfection, uptake of Tc-99m MIBI and I-125 increased up to {approx}1.5-fold and approximately 25-fold compared to control. Ad-shMDR/NIS-cotransfected HCT15 cell showed enhanced cytotoxicity by doxorubicin and I-131 compared to control. Tc-99m MIBI and I-131 images demonstrated that in Ad-shMDR/NIS-cotransfected tumor xenograft were 2 and 10 times higher than that in non-intratumoral injected tumor xenograft. Therapy with I-131, or both doxorubicin and I-131 were revealed enhanced tumor regression than control group. Suppression of mdr1 gene expression and enhanced iodine uptake can be produced by shMDR and NIS gene transfection. Dual therapy with doxorubicin and radioiodine followed by transfection of shMDR/NIS gene can be effectively used in MDR expressing cancer cell.

  1. Impacts of ABCB1 (G1199A) polymorphism on resistance, uptake, and efflux to steroid drugs.

    Science.gov (United States)

    Peng, Rui; Zhang, Hong; Zhang, Ying; Wei, Dan-Yun

    2016-10-01

    1. P-glycoprotein (P-gp) substrates, including steroid drugs, involve in the inter-individual differences in resistant phenotype. This study was performed to evaluate whether G1199A polymorphism in ABCB1 gene can alter the sensitivity, accumulation, and transepithelial efflux to steroids in LLC-PK1 cells. 2. The stable recombinant LLC-PK1 cell lines transfected with ABCB1 1199G and ABCB1 1199A were used to assess the sensitivity, accumulation, and transepithelial permeability to steroids. 3. The cells transfected with 1199A allele displayed stronger resistance to aldosterone, dexamethasone, and cortisol (2.5-, 2.0-, and 1.6-fold, respectively) than cells overexpressing 1199G allele, while the two types of recombinant cells showed a similar resistance to corticosterone. The accumulation of aldosterone, dexamethasone, and cortisol in recombinant 1199A cells were significantly decreased when compared to 1199G cells (2.9-, 4.4-, and 3.9-fold, respectively). The net efflux ratios of P-gp-mediated aldosterone, dexamethasone, and cortisol in cells expressing 1199A allele were apparently greater than cells transfected with 1199G allele (3.3-, 3.5-, and 4.0-fold, respectively). 4. The impacts of ABCB1 (G1199A) single nucleotide polymorphism on the efflux of P-gp substrates presented as drug-specific. Overall, the transport ability of P-gp-dependent steroid drugs in recombinant model overexpressing variant 1199A allele is stronger in comparison to cells overexpressing wild-type 1199G allele. Therefore, the ABCB1 (G1199A) polymorphism may affect effective steroids concentration in target cells by regulating the drug transport and distribution. PMID:26822676

  2. Establishment and characterization of an MDCK cell line stably-transfected with chicken Abcb1 encoding P-glycoprotein.

    Science.gov (United States)

    Sun, Yong; Guo, Tingting; Guo, Dawei; Guo, Li; Chen, Li; Zhang, Yu; Wang, Liping

    2016-06-01

    Chicken P-glycoprotein (chP-gp), encoded by Abcb1, determines the bioavailability because of its effect on pharmacokinetics of various drugs. However, comprehensive studies on chP-gp are still limited. In this study, the chicken full-length cDNA was first successfully cloned and then stably expressed in MDCK cell line. The open reading frame of chicken Abcb1 consists of 3864 nucleotides, encoding for a 1287-amino acid protein. Sequence alignments analysis showed that chicken P-gp had high identities with the homologues of turkey (95%), human (72%), pig (72%), rat (71%) and cattle (68%). The efflux ratio of rhodamine123 (Rho123, a human P-gp substrate) in chAbcb1 transfected MDCK cells was significantly higher than that in the wild type MDCK cell (6.24 vs 1.64, P<0.05), suggesting a good transporting function of chicken P-gp overexpressed in the transfected cell. Importantly, MDCK-chAbcb1 cells, unlike Caco-2 cells, exhibited biphasic saturation kinetics in transporting Rho123. In conclusion, an MDCK cell line stably expressing chAbcb1 was successfully established, which could provide a new cell model to screen its substrates and inhibitors and study the drug-drug interaction medicated via chicken P-gp. PMID:27234533

  3. Dioscin enhances methotrexate absorption by down-regulating MDR1 in vitro and in vivo

    International Nuclear Information System (INIS)

    The purpose of this study was to investigate the enhancing effect of dioscin on the absorption of methotrexate (MTX) and clarify the molecular mechanism involved in vivo and in vitro. Dioscin increased MTX chemosensitivity and transepithelial flux in the absorptive direction, significantly inhibiting multidrug resistance 1 (MDR1) mRNA and protein expression and MDR1 promoter and nuclear factor κ-B (NF-κB) activities in Caco-2 cells. Moreover, inhibitor κB-α (IκB-α) degradation was inhibited by dioscin. Dioscin enhanced the intracellular concentration of MTX by down-regulating MDR1 expression through a mechanism that involves NF-κB signaling pathway inhibition in Caco-2 cells. Dioscin strengthened MTX absorption by inhibiting MDR1 expression in rat intestine. In addition, even though MTX is absorbed into the enterocytes, there was no increase in toxicity observed, and that, in fact, decreased toxicity was seen. - Highlights: • Dioscin raised MTX concentration by inhibiting MDR1 in Caco-2 cells. • Dioscin suppresses MDR1 by inhibiting NF-κB signaling pathway in Caco-2 cells. • Dioscin can enhance MTX absorption via inhibiting MDR1 in vivo and in vitro. • Dioscin did not increase MTX-induced gastrointestinal mucosal toxicity

  4. Dioscin enhances methotrexate absorption by down-regulating MDR1 in vitro and in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lijuan, E-mail: jlwang1979@163.com [Department of Clinical Pharmacology, College of Pharmacy, Dalian Medical University, Dalian, Liaoning (China); Wang, Changyuan, E-mail: wangcyuan@163.com [Department of Clinical Pharmacology, College of Pharmacy, Dalian Medical University, Dalian, Liaoning (China); Provincial Key Laboratory for Pharmacokinetics and Transport, Liaoning, Dalian Medical University, Dalian, Liaoning (China); Peng, Jinyong, E-mail: jinyongpeng2005@163.com [Department of Clinical Pharmacology, College of Pharmacy, Dalian Medical University, Dalian, Liaoning (China); Provincial Key Laboratory for Pharmacokinetics and Transport, Liaoning, Dalian Medical University, Dalian, Liaoning (China); Liu, Qi, E-mail: llaqii@yahoo.com.cn [Department of Clinical Pharmacology, College of Pharmacy, Dalian Medical University, Dalian, Liaoning (China); Provincial Key Laboratory for Pharmacokinetics and Transport, Liaoning, Dalian Medical University, Dalian, Liaoning (China); Meng, Qiang, E-mail: mengq531@yahoo.cn [Department of Clinical Pharmacology, College of Pharmacy, Dalian Medical University, Dalian, Liaoning (China); Provincial Key Laboratory for Pharmacokinetics and Transport, Liaoning, Dalian Medical University, Dalian, Liaoning (China); Sun, Huijun, E-mail: sunhuijun@hotmail.com [Department of Clinical Pharmacology, College of Pharmacy, Dalian Medical University, Dalian, Liaoning (China); Provincial Key Laboratory for Pharmacokinetics and Transport, Liaoning, Dalian Medical University, Dalian, Liaoning (China); Huo, Xiaokui, E-mail: huoxiaokui@163.com [Department of Clinical Pharmacology, College of Pharmacy, Dalian Medical University, Dalian, Liaoning (China); Provincial Key Laboratory for Pharmacokinetics and Transport, Liaoning, Dalian Medical University, Dalian, Liaoning (China); and others

    2014-06-01

    The purpose of this study was to investigate the enhancing effect of dioscin on the absorption of methotrexate (MTX) and clarify the molecular mechanism involved in vivo and in vitro. Dioscin increased MTX chemosensitivity and transepithelial flux in the absorptive direction, significantly inhibiting multidrug resistance 1 (MDR1) mRNA and protein expression and MDR1 promoter and nuclear factor κ-B (NF-κB) activities in Caco-2 cells. Moreover, inhibitor κB-α (IκB-α) degradation was inhibited by dioscin. Dioscin enhanced the intracellular concentration of MTX by down-regulating MDR1 expression through a mechanism that involves NF-κB signaling pathway inhibition in Caco-2 cells. Dioscin strengthened MTX absorption by inhibiting MDR1 expression in rat intestine. In addition, even though MTX is absorbed into the enterocytes, there was no increase in toxicity observed, and that, in fact, decreased toxicity was seen. - Highlights: • Dioscin raised MTX concentration by inhibiting MDR1 in Caco-2 cells. • Dioscin suppresses MDR1 by inhibiting NF-κB signaling pathway in Caco-2 cells. • Dioscin can enhance MTX absorption via inhibiting MDR1 in vivo and in vitro. • Dioscin did not increase MTX-induced gastrointestinal mucosal toxicity.

  5. Specificity of drug transport mediated by CaMDR1: a major facilitator of Candida albicans

    Indian Academy of Sciences (India)

    Avmeet Kohli; Vinita Gupta; Shankarling Krishnamurthy; Seyed E Hasnain; Rajendra Prasad

    2001-09-01

    CaMDR1 encodes a major facilitator superfamily (MFS) protein in Candida albicans whose expression has been linked to azole resistance and which is frequently encountered in this human pathogenic yeast. In this report we have overexpressed CaMdr1p in Sf9 insect cells and demonstrated for the first time that it can mediate methotrexate (MTX) and fluconazole (FLC) transport. MTX appeared to be a better substrate for CaMdr1p among these two tested drugs. Due to severe toxicity of these drugs to insect cells, further characterization of CaMdr1p as a drug transporter could not be done with this system. Therefore, as an alternative, CaMdr1p and Cdr1p, which is an ABC protein (ATP binding cassette) also involved in azole resistance in C. albicans, were independently expressed in a common hypersensitive host JG436 of Saccharomyces cerevisiae. This allowed a better comparison between the functionality of the two export pumps. We observed that while both FLC and MTX are effluxed by CaMdr1p, MTX appeared to be a poor substrate for Cdr1p. JG436 cells expressing Cdr1p thus conferred resistance to other antifungal drugs but remained hypersensitive to MTX. Since MTX is preferentially transported by CaMdr1p, it can be used for studying the function of this MFS protein.

  6. 多剤耐性遺伝子(MDR1)過剰発現肝細胞癌に対するelectrochemotherapyの有用性に関する基礎的検討

    OpenAIRE

    西脇, 功

    2003-01-01

    The aim of this study was to investigate the role of electroporation in thetreatment of carcinoma expressing multidrug resistance gene 1 (MDR1). The cells stablyexpressing MDR1 gene (BNL/MDR1-Bulk) and the clone expressing the MDR1 gene atthe highest level (BNL/MDR1-Clone) were established by transducing human MDR1gene into the mouse hepatocellular carcinoma (HCC) cell line, BNLIME.7R.1. Theexpressions of P-glycoprotein on the cell surface of the established HCC cells,BNL/MDR1-Bulk and BNL/MD...

  7. Case-control association study of ABCB1 gene and major depressive disorder in a local Chinese Han population

    Directory of Open Access Journals (Sweden)

    Xie WW

    2015-08-01

    Full Text Available Wei-Wei Xie,1,2* Lin Zhang,1* Ren-Rong Wu,1 Yan Yu,3 Jing-Ping Zhao,1 Le-Hua Li1 1Mental Health Institute of the Second Xiangya Hospital, National Technology Institute of Psychiatry, Key Laboratory of Psychiatry and Mental Health of Hunan Province, Central South University, Changsha, Hunan, 2Department of Psychiatry, Ningbo Kangning Hospital, Ningbo, 3People’s Hospital of Hunan Province, Changsha, People’s Republic of China *These authors contributed equally to this work Background: Human P-glycoprotein encoded by the ATP-binding cassette sub-family B member 1 (ABCB1 gene is expressed in the blood–brain barrier. ABCB1 protects the brain from many drugs and toxins such as glucocorticoids through the efflux pump. Recent evidence suggests that a specific allele of the ABCB1 gene confers susceptibility to major depressive disorder (MDD in the Japanese population. The aim of this study was to explore the association of ABCB1 gene polymorphisms with MDD in a local Chinese Han population.Methods: Two hundred and ninety-two MDD patients and 208 unrelated individuals were matched by age and sex and examined using a case-control design. Six single nucleotide polymorphisms (SNPs of the ABCB1 gene, including rs1045642, rs2032583, rs2032582, rs2235040, rs1128503, and rs2235015, were genotyped by ligase detection reaction and multiplex polymerase chain reaction. Linkage disequilibrium and haplotype analysis were investigated in the two study groups. Results: Significant protection for MDD individuals carrying the TG haplotype of rs1045642–rs2032582 was observed (odds ratio 0.470, 95% confidence interval 0.251–0.897, P=0.01.The rs2032582 (G2677T and rs1128503 (C1236T SNPs of ABCB1 showed nominal associations with MDD; the other four SNPs of the ABCB1 gene were not associated with MDD.Conclusion: Chinese individuals carrying the TG haplotype of rs1045642–rs2032582 had a nearly 53% lower risk of developing MDD. To the best of our

  8. Impact of ABCB1 1236C > T-2677G > T-3435C > T polymorphisms on the anti-proliferative activity of imatinib, nilotinib, dasatinib and ponatinib

    Science.gov (United States)

    Dessilly, Géraldine; Panin, Nadtha; Elens, Laure; Haufroid, Vincent; Demoulin, Jean-Baptiste

    2016-01-01

    Overexpression of ABCB1 (also called P-glycoprotein) confers resistance to multiple anticancer drugs, including tyrosine kinase inhibitors (TKIs). Several ABCB1 single nucleotide polymorphisms affect the transporter activity. The most common ABCB1 variants are 1236C > T, 2677G > T, 3435C > T and have been associated with clinical response to imatinib in chronic myelogenous leukaemia (CML) in some studies. We evaluated the impact of these polymorphisms on the anti-proliferative effect and the intracellular accumulation of TKIs (imatinib, nilotinib, dasatinib and ponatinib) in transfected HEK293 and K562 cells. ABCB1 overexpression increased the resistance of cells to doxorubicin, vinblastine and TKIs. Imatinib anti-proliferative effect and accumulation were decreased to a larger extent in cells expressing the ABCB1 wild-type protein compared with the 1236T-2677T-3435T variant relatively to control cells. By contrast, ABCB1 polymorphisms influenced the activity of nilotinib, dasatinib and ponatinib to a much lesser extent. In conclusion, our data suggest that wild-type ABCB1 exports imatinib more efficiently than the 1236T-2677T-3435T variant protein, providing a molecular basis for the reported association between ABCB1 polymorphisms and the response to imatinib in CML. Our results also point to a weaker impact of ABCB1 polymorphisms on the activity of nilotinib, dasatinib and ponatinib. PMID:27405085

  9. Identification of a Cryptic Bacterial Promoter in Mouse (mdr1a P-Glycoprotein cDNA.

    Directory of Open Access Journals (Sweden)

    Kristen M Pluchino

    Full Text Available The efflux transporter P-glycoprotein (P-gp is an important mediator of various pharmacokinetic parameters, being expressed at numerous physiological barriers and also in multidrug-resistant cancer cells. Molecular cloning of homologous cDNAs is an important tool for the characterization of functional differences in P-gp between species. However, plasmids containing mouse mdr1a cDNA display significant genetic instability during cloning in bacteria, indicating that mdr1a cDNA may be somehow toxic to bacteria, allowing only clones containing mutations that abrogate this toxicity to survive transformation. We demonstrate here the presence of a cryptic promoter in mouse mdr1a cDNA that causes mouse P-gp expression in bacteria. This expression may account for the observed toxicity of mdr1a DNA to bacteria. Sigma 70 binding site analysis and GFP reporter plasmids were used to identify sequences in the first 321 bps of mdr1a cDNA capable of initiating bacterial protein expression. An mdr1a M107L cDNA containing a single residue mutation at the proposed translational start site was shown to allow sub-cloning of mdr1a in E. coli while retaining transport properties similar to wild-type P-gp. This mutant mdr1a cDNA may prove useful for efficient cloning of mdr1a in E. coli.

  10. Modulation of human multidrug-resistance MDR-1 gene by natural curcuminoids

    Directory of Open Access Journals (Sweden)

    Buddhasukh Duang

    2004-04-01

    Full Text Available Abstract Background Multidrug resistance (MDR is a phenomenon that is often associated with decreased intracellular drug accumulation in patient's tumor cells resulting from enhanced drug efflux. It is related to the overexpression of a membrane protein, P-glycoprotein (Pgp-170, thereby reducing drug cytotoxicity. A variety of studies have tried to find MDR modulators which increase drug accumulation in cancer cells. Methods In this study, natural curcuminoids, pure curcumin, demethoxycurcumin and bisdemethoxycurcumin, isolated from turmeric (Curcuma longa Linn, were compared for their potential ability to modulate the human MDR-1 gene expression in multidrug resistant human cervical carcinoma cell line, KB-V1 by Western blot analysis and RT-PCR. Results Western blot analysis and RT-PCR showed that all the three curcuminoids inhibited MDR-1 gene expression, and bisdemethoxycurcumin produced maximum effect. In additional studies we found that commercial grade curcuminoid (approximately 77% curcumin, 17% demethoxycurcumin and 3% bisdemthoxycurcumin decreased MDR-1 gene expression in a dose dependent manner and had about the same potent inhibitory effect on MDR-1 gene expression as our natural curcuminoid mixtures. Conclusion These results indicate that bisdemethoxycurcumin is the most active of the curcuminoids present in turmeric for modulation of MDR-1 gene. Treatment of drug resistant KB-V1 cells with curcumin increased their sensitivity to vinblastine, which was consistent with a decreased MDR-1 gene product, a P-glycoprotein, on the cell plasma membrane. Although many drugs that prevent the P-glycoprotein function have been reported, this report describes the inhibition of MDR-1 expression by a phytochemical. The modulation of MDR-1 expression may be an attractive target for new chemosensitizing agents.

  11. Significance of MDR1 and multiple drug resistance in refractory human epileptic brain

    Directory of Open Access Journals (Sweden)

    Dini Gabriele

    2004-10-01

    Full Text Available Abstract Background The multiple drug resistance protein (MDR1/P-glycoprotein is overexpressed in glia and blood-brain barrier (BBB endothelium in drug refractory human epileptic tissue. Since various antiepileptic drugs (AEDs can act as substrates for MDR1, the enhanced expression/function of this protein may increase their active extrusion from the brain, resulting in decreased responsiveness to AEDs. Methods Human drug resistant epileptic brain tissues were collected after surgical resection. Astrocyte cell cultures were established from these tissues, and commercially available normal human astrocytes were used as controls. Uptake of fluorescent doxorubicin and radioactive-labeled Phenytoin was measured in the two cell populations, and the effect of MDR1 blockers was evaluated. Frozen human epileptic brain tissue slices were double immunostained to locate MDR1 in neurons and glia. Other slices were exposed to toxic concentrations of Phenytoin to study cell viability in the presence or absence of a specific MDR1 blocker. Results MDR1 was overexpressed in blood vessels, astrocytes and neurons in human epileptic drug-resistant brain. In addition, MDR1-mediated cellular drug extrusion was increased in human 'epileptic' astrocytes compared to 'normal' ones. Concomitantly, cell viability in the presence of cytotoxic compounds was increased. Conclusions Overexpression of MDR1 in different cell types in drug-resistant epileptic human brain leads to functional alterations, not all of which are linked to drug pharmacokinetics. In particular, the modulation of glioneuronal MDR1 function in epileptic brain in the presence of toxic concentrations of xenobiotics may constitute a novel cytoprotective mechanism.

  12. Orally administered extract from Prunella vulgaris attenuates spontaneous colitis in mdr1a-/-mice

    Institute of Scientific and Technical Information of China (English)

    Kelley; MK; Haarberg; Meghan; J; Wymore; Brand; Anne-Marie; C; Overstreet; Catherine; C; Hauck; Patricia; A; Murphy; Jesse; M; Hostetter; Amanda; E; Ramer-Tait; Michael; J; Wannemuehler

    2015-01-01

    AIM: To investigate the ability of a Prunella vulgaris(P. vulgaris) ethanolic extract to attenuate spontaneous typhlocolitis in mdr1a-/- mice. METHODS: Vehicle(5% ethanol) or P. vulgaris ethanolic extract(2.4 mg/d) were administered daily by oral gavage to mdr1a-/- or wild type FVBWT mice from 6 wk of age up to 20 wk of age. Clinical signs of disease were noted by monitoring weight loss. Mice experiencingweight loss in excess of 15% were removed from the study. At the time mice were removed from the study, blood and colon tissue were collected for analyses that included histological evaluation of lesions, inflammatory cytokine levels, and myeloperoxidase activity. RESULTS: Administration of P. vulgaris extracts to mdr1a-/- mice delayed onset of colitis and reduced severity of mucosal inflammation when compared to vehicle-treated mdr1a-/- mice. Oral administration of the P. vulgaris extract resulted in reduced(P < 0.05) serum levels of IL-10(4.6 ± 2 vs 19.4 ± 4), CXCL9(1319.0 ± 277 vs 3901.0 ± 858), and TNFα(9.9 ± 3 vs 14.8 ± 1) as well as reduced gene expression by more than two-fold for Ccl2, Ccl20, Cxcl1, Cxcl9, IL-1 α, Mmp10, VCAM-1, ICAM, IL-2, and TNFα in the colonic mucosa of mdr1a-/- mice compared to vehicle-treated mdr1a-/-mice. Histologically, several microscopic parameters were reduced(P < 0.05) in P. vulgaris-treated mdr1a-/-mice, as was myeloperoxidase activity in the colon(2.49 ± 0.16 vs 3.36 ± 0.06, P < 0.05). The numbers of CD4+ T cells(2031.9 ± 412.1 vs 5054.5 ± 809.5) and germinal center B cells(2749.6 ± 473.7 vs 4934.0 ± 645.9) observed in the cecal tonsils of P. vulgaris-treated mdr1a-/- were significantly reduced(P < 0.05) from vehicle-treated mdr1a-/- mice. Vehicle-treated mdr1a-/- mice were found to produce serum antibodies to antigens derived from members of the intestinal microbiota, indicative of severe colitis and a loss of adaptive tolerance to the members of the microbiota. These serum antibodies were greatly reduced or

  13. The multidrug resistance 1 (MDR1) gene polymorphism G-rs3789243-A is not associated with disease susceptibility in Norwegian patients with colorectal adenoma and colorectal cancer; a case control study

    DEFF Research Database (Denmark)

    Andersen, V.; Agerstjerne, L.; Jensen, D.;

    2009-01-01

    Background: Smoking, dietary factors, and alcohol consumption are known life style factors contributing to gastrointestinal carcinogenesis. Genetic variations in carcinogen handling may affect cancer risk. The multidrug resistance 1(MDR1/ABCB1) gene encodes the transport protein P-glycoprotein (a...... in inflammation, and may thereby affect the risk of malignity. Hence, genetic variations that modify the function of P-glycoprotein may be associated with the risk of colorectal cancer (CRC). We have previously found an association between the MDR1 intron 3 G-rs3789243-A polymorphism and the risk of CRC...

  14. Small Interfering RNA Targeting MDR1 Inhibits Ovarian Cancer Growth and Increases Efficacy of Chemotherapy in vivo

    Institute of Scientific and Technical Information of China (English)

    Fu-jun Liu; Guo-lan Gao; Kai-jia Tu; Li-qun Yu; Jun Gao

    2009-01-01

    Objective: To further validate a knockdown approach for circumventing the multidrug resistance gene (MDR1), we used small interfering RNA(siRNA) targeting MDR1 gene to inhibit the expression of MDR1 gene and P-glycoprotein(P-gp) in vivo.Methods: Ascite tumor xenografts were established by implanting human ovarian carcinoma cells SKOV3/AR intraperitoneally into the nude mice. The mice were randomized into the following three treatment groups with each group six mice respectively: Taxol, Taxol with lipofectamine and Taxol with siRNA/MDR1- lipofectamine intraperitoneal injection. The tumor growth rate and the ascite growth rate of mice were investigated. The expressions of MDR1 gene and P-gp in mice were determined by reverse transcription-polymerase chain reaction(RT-PCR) and immunohistochemistry respctively.Results: The growth of tumors and ascites in mice treated with Taxol and siRNA/MDR1- lipofectamine was significantly inhibited compared with those in mice of other groups. After 28 days' treatment, the average tumor weight and ascite volume decreased by 43.6% and 29.7% in the group treated with Taxol and siRNA/MDR1-lipofectamine compared with these treated with Taxol alone (P<0.001). The expressions of MDR1 gene and P-gp in the group treated with Taxol and siRNA/MDR1-lipofectamine were also decreased compared with those in the group treated with Taxol alone (P<0.001).Conclusion: Small interfering RNA targeting-MDR1 can effectively and specifically suppress the expression of MDR1(P-glycoprotein) and inhibit ovarian cancer growth in vivo.

  15. 一种针对mdr1基因的寡核苷酸-阿霉素偶联物:对KB-A-1细胞的毒性及其抑制P-gp蛋白表达的效果%A novel antisense oligodeoxynucleotide-doxorubicin conjugate against the multidrug resistance gene mdr1:inhibition to KB-A-1 cell and P-glycoprotein expression

    Institute of Scientific and Technical Information of China (English)

    詹晓云; 任宇红; 张强; 卢艳花; 魏东芝; 刘建文

    2004-01-01

    Over-expression of P-glycoprotein(P-gp) on the surface of tumor cells that works as a membrane pump enhancing the drug efflux is regarded as a main candidate mechanism of multidrug resistance(MDR). And mdr1 is one of the two main genes that encode P-gp in human cells. In this study, a novel conjugate made of mdr 1-anti-sense oligodeoxynucleotide(ODN) and a potent anticancer drug doxorubicin was constructed. The cytotoxicity of the conjugate as well as the effect of the conjugate on the modulation of P-gp-mediated MDR in KB-A-1 cell lines was studied. The molecular mechanism of its regulation effect was also investigated. METHODS: Multidrug resistant KB-A-1 cell lines were used. MTF was applied to measure the cytotoxicity of the conjugate and doxorubicin to KB-A-1 cells.Effect of the conjugate on intracellular doxorubicin accumulation was determined by HPLC. RT-PCR and Western blot were used to determine the expression of mdr 1 gene and P-glycoprotein in KB-A-1 cells. RESULRTS: The results showed that the conjugate exhibited more cytotoxicity than ODN, and also it could promote the cytotoxicity of doxorubicin to KB-A-1 cells. The IC50 of doxorubicin dropped from 24 to 18 μg·ml-1. The results of RT-PCR and Western blot analysis illuminated that conjugate might down-regulate the P-gp expression. CONCLUSION: All the findings suggest that the conjugate is more potential for efficient reversal of MDR phenomenon than free ODN.The study indicated that such a conjugate should be a new feasible and efficient anti-sense reagent both in lab research and further in clinical therapy.%目的:癌细胞膜上P-gp糖蛋白的过量表达是肿瘤多药抗性的主要机制.人体内编码P-gp糖蛋白的基因中仅有mdr1涉及多药抗性.本研究中设计了针对mdr1的反义核酸与阿霉素的偶联物,并且对其细胞毒性进行了考察.同时对偶联物对人表皮癌细胞株KB-A-1内的P-gp蛋白的表达也做了分子水平上的研究.方法:使

  16. Polymorphisms of the ABCB1 gene in the pakistani population

    International Nuclear Information System (INIS)

    Objective: To investigate the frequency of the single nucleotide polymorphism C1236Tin exon 12 of the ABCB1 gene in Pakistani population and to compare it with published data on Asian and Caucasian populations. Study Design: Across-sectional observational study. Place and Duration of Study: Combined Military Hospital, Rawalpindi and Institute of Biomedical and Genetic Engineering (IBGE), Islamabad, from August 2012 to May 2013. Methodology: C1236T polymorphism was investigated in 426 Pakistani subjects. The frequency was compared with the published data on other Asian and Caucasian populations. Results: The frequencies of ABCB1 C1236T were 16.4% for CC, 44.1% for CT and 39.4% for TT. Pakistanis differed significantly from all the European populations compared in the distribution of the TT genotype of C1236TABCB1 (p < 0.05). The Pakistani population also differed significantly from some of the European populations in the distribution of CC and CT genotype (p < 0.05). Conclusion: There was significant difference in the genotype frequency of the ABCB1 gene compared to other populations. This study has provided a framework for future pharmacogenetic and pharmacokinetic studies on this polymorphic variant of ABCB1 gene in the Pakistani population. (author)

  17. Expression of MDR1,P-gp and GST-pi in Patients With Refractory Epilepsy%多药耐药基因1和P糖蛋白及谷胱甘肽S转移酶在难治性癫痫中的表达研究

    Institute of Scientific and Technical Information of China (English)

    于云莉; 史梦婷; 楚兰

    2015-01-01

    情况无明显相关性。%Objective To investigate the pathogenesis of refractory epilepsy by detecting the expression of MDR1, P - gp and GST - pi in peripheral blood of patients with refractory epilepsy and to detect the expression levels of the three indexes in patients with different types of epilepsy seizure,different epileptic discharge areas shown by V - EEG and different types of medication. Methods We enrolled 31 patients who were definitely diagnosed with sporadic refractory epilepsy in the Affiliated Hospital of Guizhou Medical University from March 2012 to March 2013 as the refractory group. Another 33 epilepsy patients who were treated well by antiepileptic drug in the same period were also enrolled as the effective group. Fluorescent quantitation method was employed to detect the change of relative gene expression of MDR1 and GST - pi in peripheral blood,and flow cytometry was employed to detect the expression of P - gp,an expression product of MDR1 in peripheral blood. Comparison was made in the expression of the three indexes among patients with different types of epilepsy in combination with clinical features,types of epilepsy seizure and abnormal discharge areas shown by long - term video EEG and different medications. Results Refractory group was higher(P ﹤ 0. 01)than effective group in the gene relative expression of MDR1 and GST - pi and P - gp level of white cells. The patients with different epilepsy seizure types in two groups were no significantly different( P ﹥ 0. 05) in the gene relative expression of MDR1 and GST - pi and P - gp level of white cells. Patients with different abnormal discharge areas shown by V - EEG were not significantly different(P ﹥ 0. 05)in the gene relative expression of MDR1 and GST - pi and P - gp level of white cells. Patients with different medications were not significantly different( P ﹥ 0. 05) in the gene relative expression of MDR1;patients with different medications were significantly different( P

  18. MDR-1 and MRP2 gene polymorphisms in Mexican epileptic pediatric patients with complex partial seizures.

    Directory of Open Access Journals (Sweden)

    David eEscalante-Santiago

    2014-10-01

    Full Text Available Although the Pgp efflux transport protein is overexpressed in resected tissue of patients with epilepsy, the presence of polymorphisms in MDR1 / ABCB1 and MRP2 / ABCC2 in patients with antiepileptic-drugs resistant epilepsy is controversial. The aim of this study was to perform an exploratory study to identify nucleotide changes and search new and reported mutations in patients with antiepileptic-drugs resistant epilepsy (ADR and patients with good response to anti-epileptic drugs (CTR in a rigorously selected population. We analyzed 22 samples from drug-resistant patients with epilepsy and 7 samples from patients with good response to anti-epileptic drugs. Genomic DNA was obtained from leukocytes. Eleven exons in both genes were genotyped. The concentration of drugs in saliva and plasma was determined. The concentration of valproic acid in saliva was lower in ADR than in CRT. In ABCB1, five reported SNPs and five unreported nucleotide changes were identified; rs2229109 (GA and rs2032582 (AT and AG were found only in the ADR. Of six SNPs associated with the ABCC2 that were found in the study population, rs3740066 (TT and 66744T>A (TG were found only in the ADR. The strongest risk factor in the ABCB1 gene was identified as the TA genotype of rs2032582, whereas for the ABCC2 gene the strongest risk factor was the T allele of rs3740066. The screening of SNPs in ACBC1 and ABCC2 indicates that the Mexican patients with epilepsy in this study display frequently reported ABCC1 polymorphisms; however, in the study subjects with a higher risk factor for drug resistance, new nucleotide changes were found in the ABCC2 gene. Thus, the population of Mexican patients with AED-resistant epilepsy used in this study exhibits genetic variability with respect to those reported in other study populations; however, it is necessary to explore this polymorphism in a larger population of patients with AED-resistant epilepsy.

  19. MDR1 overexpression inhibits chemotherapy-induced toxicity of granulosa cells

    Science.gov (United States)

    Salih, Sana M

    2011-01-01

    OBJECTIVE To protect granulosa cells from chemotherapy-induced toxicity by retrovirus-mediated multidrug resistance gene (MDR1) transfection. DESIGN Laboratory study. SETTING Academic research laboratory in a university hospital. INTERVENTION(S) KK15 immortalized murine granulosa cell line was transiently transduced with sf91m3 retrovirus vector carrying MDR1 cDNA that encodes P-glycoprtoein (P-gp). Transduced cells were selected with colchicine and treated with doxorubicin or paclitaxel for 24–72 hours. The expression and function of MDR1 and the mRNA expression of selected steroidogenesis enzymes were evaluated by flow cytometry, cell viability assays, Western blot, and RT-PCR. MAIN OUTCOME MEASURE(S) Viability of sf91m3-transduced KK15 cells after treatment with doxorubicin and paclitaxel. RESULT(S) sf91m3-transduced KK15 demonstrated high expression of biologically active MDR1 as shown by flow cytometry analysis and immunoblotting using P-gp monoclonal antibody and Rhodamine 123 efflux assays. sf91m3-transduced KK15 exhibited significant resistance to toxicity of 10uM paclitaxel(p≤0.001). MDR1-transduced KK15 cells were also protected from doxorubicin toxicity (10nM to 2.5uM) as shown by cell viability assay (p≤0.02). Both flow cytometry and cell viability assay showed that the protection of KK15 from doxorubicin toxicity was lost at 5 uM of doxorubicin; equivalent to 500 times LD50 (p≥0.05). sf91m3-transduced KK15 showed normal mRNA expression of a panel of selected steroidogenesis enzymes. CONCLUSION(S) Retroviral gene delivery of human MDR1 inhibited chemotherapy- induced granulosa cell toxicity and offered chemoprotection in an in vitro model. PMID:21316663

  20. Clopidogrel Resistance with ABCB 1%ABCB1与氯吡格雷抵抗的研究进展

    Institute of Scientific and Technical Information of China (English)

    路英杰; 王立峰; 张旭昌; 王晓云

    2012-01-01

    氯吡格雷和阿司匹林双联抗血小板已是急性冠状动脉综合征和经皮冠脉介入术后的标准治疗,因此氯吡格雷抵抗越来越受到人们的关注,但焦点更多的集中在氧吡格雷氧化代谢基因(P2Y12、CYP3A4等)多态性方面,而对氯吡格雷吸收方面基因多态性的关注相对较少,本文就调控氯吡格雷在肠道吸收的基因(ABCB1)进行综述,并探讨其多态性与氯吡格雷抵抗的关系.%Clopidogrel and aspirin thermodynamie antiplatelet is a postoperative standard treatment of acute coronary syndrome and percutaneous coronary intervention (pci). People pay more and more attention to clopidogrel resistance, but more focus is concentrated on clopidogrel oxidative metabolism of genes (P2Y12 CYP3A4 etc.)polymorphism, gene polymorphism on absorption is few concerned.The gene (ABCB1) which regulates clopidogrel in intestinal absorption will be reviewed in this article,and discuss the relationship between the polymorphism of ABCB1 and clopidogrel resistance.

  1. Genomewide analysis of ABCBs with a focus on ABCB1 and ABCB19 in Malus domestica

    Indian Academy of Sciences (India)

    Juan Juan Ma; Mingyu Han

    2016-03-01

    The B subfamily of ATP-binding cassette (ABC) proteins (ABCB) plays a vital role in auxin efflux. However, no systematic study has been done in apple. In this study, we performed genomewide identification and expression analyses of the ABCB family in Malus domestica for the first time. We identified a total of 25 apple ABCBs that were divided into three clusters based on the phylogenetic analysis. Most ABCBs within the same cluster demonstrated a similar exon–intron organization. Additionally, the digital expression profiles of ABCB genes shed light on their functional divergence. ABCB1 and ABCB19 are two well-studied auxin efflux carrier genes, and we found that their expression levels are higher in young shoots of M106 than in young shoots of M9. Since young shoots are the main source of auxin synthesis and auxin efflux involves in tree height control. This suggests that ABCB1 and ABCB19 may also take a part in the auxin efflux and tree height control in apple.

  2. Evaluation of immunoexpression and MDR1 promoter methylation levels in prostatic tissue samples

    OpenAIRE

    Moura, Inês; Costa, Vera L.; Pais, Irene; Ribeiro, Franclim R.; Henrique, Rui; Jerónimo, Carmen

    2008-01-01

    Os objectivos deste estudo foram: (1) Determinar os níveis de metilação do promotor do MDR1 em tecido prostático com adenocarcinoma (CaP), neoplasia intraepitelial prostática de alto grau (HGPIN), hiperplasia benigna (BPH) e tecido morfologicamente normal (MNP). (2) Correlacionar os níveis de metilação com a imunoexpressão da gp-P. Os nossos resultados demonstram que a hipermetilação do MDR1 constitui um mecanismo eficaz de regulação da sua expressão. Estudos futuros permitirão av...

  3. Loperamide, an FDA-Approved Antidiarrhea Drug, Effectively Reverses the Resistance of Multidrug Resistant MCF-7/MDR1 Human Breast Cancer Cells to Doxorubicin-Induced Cytotoxicity

    OpenAIRE

    Zhou, Yanfei; Sridhar, Rajagopalan; Shan, Liang; Sha, Wei; Gu, Xinbin; Sukumar, Saraswati

    2011-01-01

    Loperamide is an FDA-approved antidiarrhea drug which acts on the μ-opioid receptors in the mesenteric plexus of large intestine and exhibits limited side effects. We hypothesized that loperamide might reverse the multidrug resistance (MDR) of human cancer cells to chemotherapeutic agents. MCF-7/MDR1 cells express high level of MDR1 and are resistant to doxorubicin. We found that loperamide significantly enhanced the cytotoxicity of doxorubicin to MCF-7/MDR1 cells in a dose-dependent manner. ...

  4. Quantifizierung der ABCB1-mRNA in Lymphozytensubpopulationen

    OpenAIRE

    Wolbergs, Daniel

    2015-01-01

    P-Glycoprotein (P-Gp) is a membrane-bound protein, which acts as an efflux-pump and reduces the intracellular concentration of its substrates. Its physiological function is the protection of the cell from toxic substances as well as the elimination of endogenous metabolic wastes. P-Gp plays an important role in cell-mediated immunity, in multi-drug resistance and in the phamacokinetics of numerous therapeutic agents. In humans P-Gp is encoded by the ABCB1-gene. A number of genetic polymorphis...

  5. Identification of a putatively multixenobiotic resistance related Abcb1 transporter in amphipod species endemic to the highly pristine Lake Baikal.

    Science.gov (United States)

    Pavlichenko, Vasiliy V; Protopopova, Marina V; Timofeyev, Maxim; Luckenbach, Till

    2015-04-01

    The fauna of Lake Baikal in Eastern Siberia, the largest freshwater body on Earth, is characterized by high degrees of biodiversity and endemism. Amphipods, a prominent taxon within the indigenous fauna, occur in an exceptionally high number of endemic species. Considering the specific water chemistry of Lake Baikal with extremely low levels of potentially toxic natural organic compounds, it seems conceivable that certain adaptions to adverse environmental factors are missing in endemic species, such as cellular defense mechanisms mitigating toxic effects of chemicals. The degree to which the endemic fauna is affected by the recently occurring anthropogenic water pollution of Lake Baikal may depend on the existence of such cellular defense mechanisms in those species. We here show that endemic amphipods express transcripts for Abcb1, a major component of the cellular multixenobiotic resistance (MXR) defense against toxic chemicals. Based on a partial abcb1 cDNA sequence from Gammarus lacustris, an amphipod species common across Northern Eurasia but only rarely found in Lake Baikal, respective homologous sequences were cloned from five amphipods endemic to Lake Baikal, Eulimnogammarus verrucosus, E. vittatus, E. cyaneus, E. marituji, and Gmelinoides fasciatus, confirming that abcb1 is transcribed in those species. The effects of thermal (25 °C) and chemical stress (1-2 mg L(-1) phenanthrene) in short-term exposures (up to 24 h) on transcript levels of abcb1 and heat shock protein 70 (hsp70), used as a proxy for cellular stress in the experiments, were exemplarily examined in E. verrucosus, E. cyaneus, and Gammarus lacustris. Whereas increases of abcb1 transcripts upon treatments occurred only in the Baikalian species E. verrucosus and E. cyaneus but not in Gammarus lacustris, changes of hsp70 transcript levels were seen in all three species. At least for species endemic to Lake Baikal, the data thus indicate that regulation of the identified amphipod abcb1 is

  6. Reversal of multi-drug resistance by pSUPER-shRNA-mdr1 in vivo and in vitro

    Institute of Scientific and Technical Information of China (English)

    Guang-Dong Pan; Jian-Qing Yang; Lv-Nan Yan; Guang-Ping Chu; Qiang Liu; Yi Xiao; Lin Yuan

    2009-01-01

    AIM: To explore the possibility of reversing multi-drug resistance (MDR) to HepG2/mdr1 in vitro and in vivo with RNA interference (RNAi).METHODS: HepG2/mdr1 was obtained by cloning the whole gene mdr1 into HepG2 cells. shRNA targeting sequence was designed to be homologous to the P-gp encoding MDR1 mRNA consensus sequence. pSUPERshRNA/mdr1 was constructed using the enzymedigested technique. HepG2/mdr1 cells were transfected with vectors of pSUPER-shRNA/mdr1 to measure their efficacy by real-time PCR for mdr1 mRNA, flow cytometry (FCM) for P-gp expression, and Rhodamine efflux, MTT method for HepG2/mdr1 function,respectively. In vivo, mice tumors were treated by injecting pSUPER-shRNA/mdr1 in situ and into intraabdominal cavity. Tumors were collected to create cell suspension and cryosections after chemothearpy with adiramycin and mytomycin.The cell suspension was incubated in RPMI-1640 supplemented with G418 to screen stable cells for appreciating the reversal of MDR.Cryosections were treated with immunohistochemistry technique to show the effectiveness of transfection and the expression of P-gp.RESULTS: pSUPER-shRNA/mdr1 was successfully constructed, which was confirmed by sequencing.The MDR phenotype of HepG2/mdr1 was decreased significantly in vitro transfection. HepG2/mdr1 showing its MDR was reversed notably in P-gp expression (11.0% vs 98.2%, P < 0.01). Real-time PCR showed that mRNA/mdr1 was lower in test groups than in control groups (18.73 ± 1.33 vs 68.03 ± 2.21, P < 0.001).Compared with HepG2, the sensitivity of HepG2/mdr1 and HepG2/mdr1-dsRNA cells to ADM was decreased by 1.64 times and 15.6 times, respectively.The accumulation of DNR in positive groups was decreased by 1.64 times and 15.6 times,respectively.The accumulation of DNR in positive groups was decreased evidently. In vivo, the p-gp expression in positive groups was significantly lower than that in control groups (65.1% vs 94.1%, P < 0.05). The tumor suppressing rate in test groups was 57

  7. Reversal of Multi-Drug Resistance by Vector-Based-ShRNA-Mdr1 In Vitro and In Vivo

    Institute of Scientific and Technical Information of China (English)

    Shi LU; Qi HUANG; Zehua WANG; Yinfeng SONG; Lijun WANG

    2009-01-01

    In order to investigate the effects of vector-based hairpin small interference RNA (shRNA) on the reversal of multi-drug resistance (mdr) of A2780/Taxol cells, a novel vector pEGFP-H1/mdr1 containing mdr1-shRNA targeting at position 2943-2963 of mdr1 was designed and synthesized.Subsequently, A2780/Taxol cells were transfected with pEGFP-H1/mdrl, and the expression of mdr1 mRNA and P-gp was detected by using RT-PCR and Western blot respectively. MTT was used to measure the 50% inhibition concentration (1C50) of Taxol to A2780/Taxol cells. The results showed that at the 24th and 48th h after transfection, the expression of mdr1 mRNA was decreased to (52.1±1.0)% and (0.01+1.7)%, and that of P-gp decreased to (88.3±2.1)% and 0%, respectively. At the 48th h after transfection, the relative reversal rate of A2780/Taxol cells to Taxol was 69.54%. In vivo, the nude mice xenografts were injected with pEGFP-H1/mdrl, and then administrated Taxol.The tumor volume in pEGFP-H1/mdr1-transfected group was significantly reduced as compared with that in blank control group or pEGFP-H1-transfected group (807.20±103.16 vs 1563.78±210.54 or 1480.78±241.24 mm3, both P<0.01). These results suggested that transfection of pEGFP-H1/mdr1 could efficiently down-regulate the expression of mdr1 mRNA and P-gp in A2780/Taxol cells, and effectively restore the sensitivity of A2780/Taxol cells to Taxol both in vitro and in vivo.

  8. Involvement of V-Ets erythroblastosis virus E26 oncogene homolog 2 in regulation of transcription activity of MDR1 gene

    Institute of Scientific and Technical Information of China (English)

    Jian Wang; Xiaoqing Zeng; Tiancheng Luo; Wei Jin; Shiyao Chen

    2012-01-01

    Over-expression of MDR1 confers multidrug resistance (MDR) in cancers and remains a major cause for the failure of chemotherapy.In the present study,we found that V-Ets erythroblastosis virus E26 oncogene homolog 2(ETS2) could activate MDR1 transcription and P-glyco-protein (P-gp) expression in SGC7901 cells.Knockdown of ETS2 attenuated MDR1 transcription and P-gp expression,and increased the sensitivity of MDR cancer cells to cytotoxic drugs that were transported by P-gp in SGC7901/VCR cells.ETS2 could bind to the ETS2 sites on the MDR1 promoter and activate its transcription.The regulation of MDR1 expression by ETS2 may provide potential ways to overcome MDR in cancer treatment.

  9. Novel understanding of ABC transporters ABCB1/MDR/P-glycoprotein, ABCC2/MRP2, and ABCG2/BCRP in colorectal pathophysiology

    DEFF Research Database (Denmark)

    Andersen, Vibeke; Svenningsen, Katrine; Almind Knudsen, Lina;

    2015-01-01

    AIM: To evaluate ATP-binding cassette (ABC) transporters in colonic pathophysiology as they had recently been related to colorectal cancer (CRC) development. METHODS: Literature search was conducted on PubMed using combinations of the following terms: ABC transporters, ATP binding cassette....../Mdr1a, abcc2/Mrp2, abcg2/Bcrp, knock-out mice, tight junction, membrane lipid function. RESULTS: Recently, human studies reported that changes in the levels of ABC transporters were early events in the adenoma-carcinoma sequence leading to CRC. A link between ABCB1, high fat diet and gut microbes...... translocation from one side to the other of the cell membrane lipid bilayer by ABC transporters affecting inflammatory response and/or function of tight junctions, phagocytosis and vesicle trafficking. Also, diet and microbes give rise to molecules which are potential substrates for the ABC transporters...

  10. Acquisition of docetaxel resistance in breast cancer cells reveals upregulation of ABCB1 expression as a key mediator of resistance accompanied by discrete upregulation of other specific genes and pathways

    DEFF Research Database (Denmark)

    Ninel Hansen, Stine; Westergaard, David; Borg Houlberg Thomsen, Mathilde;

    2015-01-01

    to be prominent at higher docetaxel concentrations (second-phase response). Additional resistance mechanisms were indicated by gene expression profiling, including genes in the interferon-inducible protein family in MCF7RES and cancer testis antigen family in MDARES. Also, upregulated expression of various ABC......The microtubule-targeting taxanes are important in breast cancer therapy, but no predictive biomarkers have yet been identified with sufficient scientific evidence to allow clinical routine use. The purposes of the present study were to develop a cell-culture-based discovery platform for docetaxel...... over 15 months. The cell lines were characterized regarding sensitivity to docetaxel and other chemotherapeutics and subjected to transcriptome-wide mRNA microarray profiling. MCF7RES and MDARES exhibited a biphasic growth inhibition pattern at increasing docetaxel concentrations. Gene expression...

  11. MDR1 siRNA loaded hyaluronic acid-based CD44 targeted nanoparticle systems circumvent paclitaxel resistance in ovarian cancer

    Science.gov (United States)

    Yang, Xiaoqian; Lyer, Arun K.; Singh, Amit; Choy, Edwin; Hornicek, Francis J.; Amiji, Mansoor M.; Duan, Zhenfeng

    2015-02-01

    Development of multidrug resistance (MDR) is an almost universal phenomenon in patients with ovarian cancer, and this severely limits the ultimate success of chemotherapy in the clinic. Overexpression of the MDR1 gene and corresponding P-glycoprotein (Pgp) is one of the best known MDR mechanisms. MDR1 siRNA based strategies were proposed to circumvent MDR, however, systemic, safe, and effective targeted delivery is still a major challenge. Cluster of differentiation 44 (CD44) targeted hyaluronic acid (HA) based nanoparticle has been shown to successfully deliver chemotherapy agents or siRNAs into tumor cells. The goal of this study is to evaluate the ability of HA-PEI/HA-PEG to deliver MDR1 siRNA and the efficacy of the combination of HA-PEI/HA-PEG/MDR1 siRNA with paclitaxel to suppress growth of ovarian cancer. We observed that HA-PEI/HA-PEG nanoparticles can efficiently deliver MDR1 siRNA into MDR ovarian cancer cells, resulting in down-regulation of MDR1 and Pgp expression. Administration of HA-PEI/HA-PEG/MDR1 siRNA nanoparticles followed by paclitaxel treatment induced a significant inhibitory effect on the tumor growth, decreased Pgp expression and increased apoptosis in MDR ovarian cancer mice model. Our findings suggest that CD44 targeted HA-PEI/HA-PEG/MDR1 siRNA nanoparticles can serve as a therapeutic tool with great potentials to circumvent MDR in ovarian cancer.

  12. Fentanyl Enhances Hepatotoxicity of Paclitaxel via Inhibition of CYP3A4 and ABCB1 Transport Activity in Mice.

    Directory of Open Access Journals (Sweden)

    Jing-Dun Xie

    Full Text Available Fentanyl, a potent opioid analgesic that is used to treat cancer pain, is commonly administered with paclitaxel in advanced tumors. However, the effect of fentanyl on the hepatotoxicity of paclitaxel and its potential mechanism of action is not well studied. The purpose of this study was to investigate the effect of fentanyl on the hepatotoxicity of paclitaxel and its potential mechanisms of action. Pharmacokinetic parameters of paclitaxel were tested using reversed phase high-performance liquid chromatography (RP-HPLC. Aspartate transaminase (AST, alanine aminotransferase (ALT, and mouse liver histopathology were examined. Moreover, the cytotoxicity of anti-carcinogens was examined using 1-(4, 5-dimethylthiazol-2-yl-3,5-diphenylformazan (MTT, and the intracellular accumulation of doxorubicin and rhodamine 123 was detected by flow cytometry. Furthermore, the expression of ABCB1 and the activity of ABCB1 ATPase and CYP3A4 were also examined. In this study, the co-administration of fentanyl and paclitaxel prolonged the half-life (t1/2 of paclitaxel from 1.455 hours to 2.344 hours and decreased the clearance (CL from 10.997 ml/h to 7.014 ml/h in mice. Fentanyl significantly increased the levels of ALT in mice to 88.2 U/L, which is more than 2-fold higher than the level detected in the control group, and it increased the histological damage in mouse livers. Furthermore, fentanyl enhanced the cytotoxicity of anti-carcinogens that are ABCB1 substrates and increased the accumulation of doxorubicin and rhodamine 123. Additionally, fentanyl stimulated ABCB1 ATPase activity and inhibited CYP3A4 activity in the liver microsomes of mice. Our study indicates that the obvious hepatotoxicity during this co-administration was due to the inhibition of CYP3A4 activity and ABCB1 transport activity. These findings suggested that the accumulation-induced hepatotoxicity of paclitaxel when it is combined with fentanyl should be avoided.

  13. Prognostic significance of multidrug-resistance protein (MDR-1) in renal clear cell carcinomas: A five year follow-up analysis

    International Nuclear Information System (INIS)

    A large number of renal cancer patients shows poor or partial response to chemotherapy and the mechanisms have not been still understood. Multi-drug resistance is the principal mechanism by which many cancers develop resistance to chemotherapic drugs. The role of the multi-drug resistant transporter (MDR-1/P-glycoprotein), the gene product of MDR-1, and that one of the so-called multi-drug resistance associated protein (MRP), two energy-dependent efflux pumps, are commonly known to confer drug resistance. We studied MDR-1 expression in selected cases of renal cell carcinoma (RCC), clear cell type, with long-term follow-up, in order to establish its prognostic role and its possible contribution in the choice of post-surgical therapy. MDR-1 has been studied by standard LSAB-HRP immunohistochemical technique, in paraffin embedded RCC samples. Protein expression has been compared to clinical and histopathological data and to disease specific survival of RCC patients, by Kaplan-Meier curve and Cox multivariate regression analyses. Two groups of RCCs were obtained by esteeming MDR-1 expression and disease specific survival (obtained with Kaplan-Meier curve and Cox multivariate regression analyses): the first one presents low or absent MDR-1 expression and good survival; the second one is characterized by high MDR-1 expression and significant poor outcome (p < 0.05). Afterwards, we have found disease specific survival, adjusted for stages and independent of therapy: this difference of survival rates was statistically significant (p < 0.05). Stage adjusted disease specific survival rate, according to MDR-1 expression and therapy in patients affected by RCC in early stage (stage I), has revealed that the group of patients with high MDR-1 expression and without adjuvant therapy showed poor survival (p < 0.05). Cox multivariate regression analysis has confirmed that, in our cohort of RCC (clear cell type) patients, the strong association between MDR-1 and worse outcome is

  14. Analysis of mdr1-1Δ mutation of MDR1 gene in the “Cimarron Uruguayo” dog

    Directory of Open Access Journals (Sweden)

    Rosa Gagliardi B.

    2013-08-01

    Full Text Available Objective. The aim of this paper is to analyze the frequency of the mdr1-1D mutation of the MDR1 gene in a dog sample of the Uruguayan Cimarron breed with the objective of increasing the knowledge of this breed’s genome. Materials and methods. Thirty-six animals of this breed were analyzed. The MDR1 gene region, which includes the location where the mutation would be present, was amplified by PCR. Results. The mutation was not detected in any of the analyzed Uruguayan Cimarron. Conclusions. The lack of described ivermectin intoxication cases in veterinary clinic in this breed is explained by the lack of the mutation object of this study. The sequence studied in Cimarron dogs is kept compared to other breeds, except Collies and related breeds (Border Collie, Bearded Collie, Old English sheepdog.

  15. Olomoucine II, but not purvalanol A, is transported by breast cancer resistance protein (ABCG2 and P-glycoprotein (ABCB1.

    Directory of Open Access Journals (Sweden)

    Jakub Hofman

    Full Text Available Purine cyclin-dependent kinase inhibitors have been recognized as promising candidates for the treatment of various cancers; nevertheless, data regarding interaction of these substances with drug efflux transporters is still lacking. Recently, we have demonstrated inhibition of breast cancer resistance protein (ABCG2 by olomoucine II and purvalanol A and shown that these compounds are able to synergistically potentiate the antiproliferative effect of mitoxantrone, an ABCG2 substrate. In this follow up study, we investigated whether olomoucine II and purvalanol A are transported by ABCG2 and ABCB1 (P-glycoprotein. Using monolayers of MDCKII cells stably expressing human ABCB1 or ABCG2, we demonstrated that olomoucine II, but not purvalanol A, is a dual substrate of both ABCG2 and ABCB1. We, therefore, assume that pharmacokinetics of olomoucine II will be affected by both ABCB1 and ABCG2 transport proteins, which might potentially result in limited accumulation of the compound in tumor tissues or lead to drug-drug interactions. Pharmacokinetic behavior of purvalanol A, on the other hand, does not seem to be affected by either ABCG2 or ABCB1, theoretically favoring this drug in the potential treatment of efflux transporter-based multidrug resistant tumors. In addition, we observed intensive sulfatation of olomoucine II in MDCKII cell lines with subsequent active efflux of the metabolite out of the cells. Therefore, care should be taken when performing pharmacokinetic studies in MDCKII cells, especially if radiolabeled substrates are used; the generated sulfated conjugate may largely contaminate pharmacokinetic analysis and result in misleading interpretation. With regard to chemical structures of olomoucine II and purvalanol A, our data emphasize that even drugs with remarkable structure similarity may show different pharmacokinetic behavior such as interactions with ABC transporters or biotransformation enzymes.

  16. Reduced inflammatory response in cigarette smoke exposed Mrp1/Mdr1a/1b deficient mice

    Directory of Open Access Journals (Sweden)

    Postma Dirkje S

    2007-07-01

    Full Text Available Abstract Background Tobacco smoke is the principal risk factor for chronic obstructive pulmonary disease (COPD, though the mechanisms of its toxicity are still unclear. The ABC transporters multidrug resistance-associated protein 1 (MRP1 and P-glycoprotein (P-gp/MDR1 extrude a wide variety of toxic substances across cellular membranes and are highly expressed in bronchial epithelium. Their impaired function may contribute to COPD development by diminished detoxification of noxious compounds in cigarette smoke. Methods We examined whether triple knock-out (TKO mice lacking the genes for Mrp1 and Mdr1a/1b are more susceptible to develop COPD features than their wild-type (WT littermates. TKO and WT mice (six per group were exposed to 2 cigarettes twice daily by nose-only exposure or room air for 6 months. Inflammatory infiltrates were analyzed in lung sections, cytokines and chemokines in whole lung homogenates, emphysema by mean linear intercept. Multiple linear regression analysis with an interaction term was used to establish the statistical significances of differences. Results TKO mice had lower levels of interleukin (IL-7, KC (mouse IL-8, IL-12p70, IL-17, TNF-alpha, G-CSF, GM-CSF and MIP-1-alpha than WT mice independent of smoke exposure (P P P Conclusion Mrp1/Mdr1a/1b knock-out mice have a reduced inflammatory response to cigarette smoke. In addition, the expression levels of several cytokines and chemokines were also lower in lungs of Mrp1/Mdr1a/1b knock-out mice independent of smoke exposure. Further studies are required to determine whether dysfunction of MRP1 and/or P-gp contribute to the pathogenesis of COPD.

  17. The roles of variants in human multidrug resistance (MDR1 gene and their haplotypes on antiepileptic drugs response: a meta-analysis of 57 studies.

    Directory of Open Access Journals (Sweden)

    Hui Li

    Full Text Available Previous studies reported the associations between the ATP-binding cassette sub-family B member 1 (ABCB1, also known as MDR1 polymorphisms and their haplotypes with risk of response to antiepileptic drugs in epilepsy, however, the results were inconclusive.The Pubmed, Embase, Web of Science, CNKI and Chinese Biomedicine databases were searched up to July 15, 2014. Pooled odds ratios (ORs and 95% confidence intervals (CIs were calculated using a fixed-effects or random-effects model based on heterogeneity tests. Meta-regression and Galbraith plot analysis were carried out to explore the possible heterogeneity.A total of 57 studies involving 12407 patients (6083 drug-resistant and 6324 drug-responsive patients with epilepsy were included in the pooled-analysis. For all three polymorphisms (C3435T, G2677T/A, and C1236T, we observed a wide spectrum of minor allele frequencies across different ethnicities. A significantly decreased risk of AEDs resistance was observed in Caucasian patients with T allele of C3435T variant, which was still significant after adjusted by multiple testing corrections (T vs C: OR=0.83, 95%CI=0.71-0.96, p=0.01. However, no significant association was observed between the other two variants and AEDs resistance. Of their haplotypes in ABCB1 gene (all studies were in Indians and Asians, no significant association was observed with AEDs resistance. Moreover, sensitivity and Cumulative analysis showed that the results of this meta-analysis were stable.In summary, this meta-analysis demonstrated that effect of C3435T variant on risk of AEDs resistance was ethnicity-dependent, which was significant in Caucasians. Additionally, further studies in different ethnic groups are warranted to clarify possible roles of haplotypes in ABCB1 gene in AEDs resistance, especially in Caucasians.

  18. ABCB1、ABCG2与食管癌患者多药耐药的关系%Research of esophageal cancer multi-drug resistance

    Institute of Scientific and Technical Information of China (English)

    刘亮; 左静; 赵丽; 左连富; 郭建文; 王静; 刘江惠

    2011-01-01

    目的 探讨多药耐药蛋白三磷酸腺苷结合转运蛋白G2(ABCG2)蛋白和三磷酸腺苷结合转运蛋白B1(ABCB1)在食管癌组织中的表达及其意义.方法 选用80例食管癌患者手术切除标本,采用流式细胞术(FCM)方法检测80例原发性食管癌患者的癌组织、癌旁组织(距离癌2 cm)及食管切缘正常黏膜(距离癌5 cm以上)ABCG2及ABCB1蛋白的表达量.结果 ABCG2及ABCB1蛋白在食管癌组织中有较高程度的表达,表达量分别为(467.30±37.85)、(444.79±22.83),而正常食管黏膜中表达量分别为(418.41±21.70)、(401.35±16.09);其在食管癌中的表达显著高于正常黏膜(P0.05).结论 ABCG2及ABCB1参与食管癌多药耐药的形成,对于临床上食管癌的化疗具有一定的指导意义.%Objective To explore the mechanism of esophageal cancer multi-drug resistance and detect the relationships between the expression of ABCB1, ABCG2 in esophageal cancer and esophageal cancer multi-drug resistance. Methods 80 cases esophageal cancer tissues were taken, including cancer, atypical hyperplasia and normal tissues. Expressions of ABCB1 and ABCG2 protein were examined by flow cytometry. Results The expressions of ABCG2, ABCB1 protein in esophageal cancer was higher than those of normal esophageal tissues significantly ( P <0.Ol ). The expressions of ABCG2, ABCBI protein in poorly cell differentiation, fibrous membrane invasion, lymph node metastasis positive esophageal cancer was higher than those of welL/moderately cell differentiation, fibrous membrane untouched, lymph node metastasis negative tissues significantly (P < 0. 05 ). The expressions of ABCG2, ABCB1 protein was no significant difference in gender and age ( P > 0. 05 ). Conclusions The high expression of ABCG2, ABCB1 protein in esophageal cancer could participate in the development of esophageal cancer and multi-drug resistance.

  19. Epigenetic modulation of the drug resistance genes MGMT, ABCB1 and ABCG2 in glioblastoma multiforme

    OpenAIRE

    Oberstadt, Moritz C.; Bien-Möller, Sandra; Weitmann, Kerstin; Herzog, Susann; Hentschel, Katharina; Rimmbach, Christian; Vogelgesang, Silke; Balz, Ellen; Fink, Matthias; Michael, Heike; Zeden, Jan-Philip; Bruckmüller, Henrike; Werk, Anneke N.; Cascorbi, Ingolf; Hoffmann, Wolfgang

    2013-01-01

    Background Resistance of the highly aggressive glioblastoma multiforme (GBM) to drug therapy is a major clinical problem resulting in a poor patient’s prognosis. Beside promoter methylation of the O 6 -methylguanine-DNA-methyltransferase (MGMT) gene the efflux transporters ABCB1 and ABCG2 have been suggested as pivotal factors contributing to drug resistance, but the methylation of ABCB1 and ABCG2 has not been assessed before in GBM. Methods Therefore, we evaluated the proportion and pr...

  20. Role of hypoxia-inducible factor-α in hepatitis-B-virus X protein-mediated MDR1 activation

    International Nuclear Information System (INIS)

    The transition from chemotherapy-responsive cancer cells to chemotherapy-resistant cancer cells is mainly accompanied by the increased expression of multi-drug resistance 1 (MDR1). We found that hepatitis-B-virus X protein (HBx) increases the transcriptional activity and protein level of MDR1 in a hepatoma cell line, H4IIE. In addition, HBx overexpression made H4IIE cells more resistant to verapamil-uptake. HBx stabilized hypoxia-inducible factor-1α (HIF-1α) and induced the nuclear translocation of C/EBPβ. Reporter gene analyses showed that HBx increased the reporter activity in the cells transfected with the reporter containing MDR1 gene promoter. Moreover, the luciferase reporter gene activity was significantly inhibited by HIF-1α siRNA but not by overexpression of C/EBP dominant negative mutant. These results imply that HBx increases the MDR1 transporter activity through the transcriptional activation of the MDR1 gene with HIF-1α activation, and suggest HIF-1α for the therapeutic target of HBV-mediated chemoresistance

  1. Abcb1 in Pigs: Molecular cloning, tissues distribution, functional analysis, and its effect on pharmacokinetics of enrofloxacin.

    Science.gov (United States)

    Guo, Tingting; Huang, Jinhu; Zhang, Hongyu; Dong, Lingling; Guo, Dawei; Guo, Li; He, Fang; Bhutto, Zohaib Ahmed; Wang, Liping

    2016-01-01

    P-glycoprotein (P-gp) is one of the best-known ATP-dependent efflux transporters, contributing to differences in pharmacokinetics and drug-drug interactions. Until now, studies on pig P-gp have been scarce. In our studies, the full-length porcine P-gp cDNA was cloned and expressed in a Madin-Darby Canine Kidney (MDCK) cell line. P-gp expression was then determined in tissues and its role in the pharmacokinetics of oral enrofloxacin in pigs was studied. The coding region of pig Abcb1 gene was 3,861 bp, encoding 1,286 amino acid residues (Mw = 141,966). Phylogenetic analysis indicated a close evolutionary relationship between porcine P-gp and those of cow and sheep. Pig P-gp was successfully stably overexpressed in MDCK cells and had efflux activity for rhodamine 123, a substrate of P-gp. Tissue distribution analysis indicated that P-gp was highly expressed in brain capillaries, small intestine, and liver. In MDCK-pAbcb1 cells, enrofloxacin was transported by P-gp with net efflux ratio of 2.48 and the efflux function was blocked by P-gp inhibitor verapamil. High expression of P-gp in the small intestine could modify the pharmacokinetics of orally administrated enrofloxacin by increasing the Cmax, AUC and Ka, which was demonstrated using verapamil, an inhibitor of P-gp. PMID:27572343

  2. Polymorphisms in the xenobiotic transporter Multidrug Resistance 1 (MDR1) and interaction with meat intake in relation to risk of colorectal cancer in a Danish prospective case-cohort study

    International Nuclear Information System (INIS)

    The xenobiotic transporters, Multidrug Resistance 1 (MDR1/ABCB1) and Breast Cancer Resistance Protein (BCRP/ABCG2) may restrict intestinal absorption of various carcinogens, including heterocyclic amines (HCA) and polycyclic aromatic hydrocarbons (PAH). Cyclooxygenase-2 (COX-2) derived prostaglandins promote gastrointestinal carcinogenesis, affecting angiogenesis, apoptosis, and invasiveness. The aim of this study was to investigate if polymorphisms in these genes were associated with risk of colorectal cancer (CRC), and to investigate possible interactions with lifestyle factors such as smoking, meat consumption, and NSAID use. The following polymorphisms were analyzed; a synonymous MDR1 C3435T (rs1045642) in exon26, G-rs3789243-A in intron3, the functional BCRP C421A (rs2231142), the two COX-2 A-1195G (rs689466) and G-765C (rs20417) in the promoter region, and the COX-2 T8473C (rs5275) polymorphisms in the 3'-untranslated region. The polymorphisms were assessed together with lifestyle factors in a nested case-cohort study of 359 cases and a random cohort sample of 765 participants from the Danish prospective Diet, Cancer and Health study. Carriers of the variant allele of MDR1 intron 3 polymorphism were at 1.52-fold higher risk of CRC than homozygous wild type allele carriers (Incidence rate ratio (IRR) = 1.52, 95% Confidence Interval (CI): 1.12-2.06). Carriers of the variant allele of MDR1 C3435T exon 26 had a lower risk of CRC than homozygous C-allele carriers (IRR = 0.71 (CI:0.50-1.00)). There was interaction between these MDR1 polymorphisms and intake of red and processed meat in relation to CRC risk. Homozygous MDR1 C3435T C-allele carriers were at 8% increased risk pr 25 gram meat per day (CI: 1.00-1.16) whereas variant allele carriers were not at increased risk (p for interaction = 0.02). COX-2 and BCRP polymorphisms were not associated with CRC risk. There was interaction between NSAID use and MDR1 C3435T and COX-2 T8473C (p-values for interaction 0

  3. BPR1K653, a novel Aurora kinase inhibitor, exhibits potent anti-proliferative activity in MDR1 (P-gp170-mediated multidrug-resistant cancer cells.

    Directory of Open Access Journals (Sweden)

    Chun Hei Antonio Cheung

    Full Text Available BACKGROUND: Over-expression of Aurora kinases promotes the tumorigenesis of cells. The aim of this study was to determine the preclinical profile of a novel pan-Aurora kinase inhibitor, BPR1K653, as a candidate for anti-cancer therapy. Since expression of the drug efflux pump, MDR1, reduces the effectiveness of various chemotherapeutic compounds in human cancers, this study also aimed to determine whether the potency of BPR1K653 could be affected by the expression of MDR1 in cancer cells. PRINCIPAL FINDINGS: BPR1K653 specifically inhibited the activity of Aurora-A and Aurora-B kinase at low nano-molar concentrations in vitro. Anti-proliferative activity of BPR1K653 was evaluated in various human cancer cell lines. Results of the clonogenic assay showed that BPR1K653 was potent in targeting a variety of cancer cell lines regardless of the tissue origin, p53 status, or expression of MDR1. At the cellular level, BPR1K653 induced endo-replication and subsequent apoptosis in both MDR1-negative and MDR1-positive cancer cells. Importantly, it showed potent activity against the growth of xenograft tumors of the human cervical carcinoma KB and KB-derived MDR1-positive KB-VIN10 cells in nude mice. Finally, BPR1K653 also exhibited favorable pharmacokinetic properties in rats. CONCLUSIONS AND SIGNIFICANCE: BPR1K653 is a novel potent anti-cancer compound, and its potency is not affected by the expression of the multiple drug resistant protein, MDR1, in cancer cells. Therefore, BPR1K653 is a promising anti-cancer compound that has potential for the management of various malignancies, particularly for patients with MDR1-related drug resistance after prolonged chemotherapeutic treatments.

  4. Genotype frequencies of polymorphic MDR1 variants in the Kazakhstani population

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    Samat Kozhakhmetov

    2014-03-01

    Full Text Available Introduction: Statins appear to be handled by an ATP-dependent membrane transporter and three SNPs (C1236T (rs1128503, G2677T (rs2032582, and C3435T (rs1045642, which capture the common genetic variation at this locus. Individuals, who carry the T allele at each SNP (i.e., the T-T-T haplotype, have higher systemic exposure to simvastatin. A triallelic thymine (T - guanine (G - adenine (A, which is  a point mutation at nucleotide 2677 in exon 22, leads to ABCB1 in a non-synonymous codons (GCT alanine, TCT serine, threonine ACT at position 893 in a cytoplasmic loop of ATP-dependent membrane transporters. Methods: Blood samples from healthy individuals were collected in the Republican Diagnostic Center, Astana, Kazakhstan. The research samples included 461 healthy people. Genomic DNA was extracted from peripheral blood using the ‘salting out’ procedure. For the MDR1 exon 21, 2677G˃T/A (Ala893Ser/Thr polymorphism was genotyped by PCR sequencing by the use of dye-terminator (ABI 3730xl sequencer. Results: The GG allele appeared in 23% of samples, the GA in 6.7%, the GT in 44%, the non-G heterozygote in 4.5%, and the non-G homozygote in 18%. These results are consistent with previously published data. Importantly, the frequency of 2677T alleles in our group was 15.4%. This represents the lowest frequency of this allele compared to published data in different populations. The frequency of the 2677T allele in Asians and Caucasians varies from 38 to 62%, and is 15% for African Americans. On the other hand, the 2677A allele frequency in the Japanese varies from 15 to 22%, and in Caucasians from 2% and 4%. The 2677A allele frequency has been found in 4.6% of samples. Conclusions: Our study further emphasizes differences between various Asian populations and the importance of repeating this genetic study  in different ethnic groups.

  5. Novel insertion mutation of ABCB1 gene in an ivermectin-sensitive Border Collie.

    Science.gov (United States)

    Han, Jae-Ik; Son, Hyoung-Won; Park, Seung-Cheol; Na, Ki-Jeong

    2010-12-01

    P-glycoprotein (P-gp) is encoded by the ABCB1 gene and acts as an efflux pump for xenobiotics. In the Border Collie, a nonsense mutation caused by a 4-base pair deletion in the ABCB1 gene is associated with a premature stop to P-gp synthesis. In this study, we examined the full-length coding sequence of the ABCB1 gene in an ivermectin-sensitive Border Collie that lacked the aforementioned deletion mutation. The sequence was compared to the corresponding sequences of a wild-type Beagle and seven ivermectin-tolerant family members of the Border Collie. When compared to the wild-type Beagle sequence, that of the ivermectin-sensitive Border Collie was found to have one insertion mutation and eight single nucleotide polymorphisms (SNPs) in the coding sequence of the ABCB1 gene. While the eight SNPs were also found in the family members' sequences, the insertion mutation was found only in the ivermectin-sensitive dog. These results suggest the possibility that the SNPs are species-specific features of the ABCB1 gene in Border Collies, and that the insertion mutation may be related to ivermectin intolerance. PMID:21113104

  6. Effect of multidrug resistance gene-1(mdr1) overexpression on in-vitro uptake of {sup 99m}Tc-sestaMIBI in murine L1210 leukemia cells

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Kyung Ah; Lee, Jae Tae; Lee, Sang Woo; Kang, Do Young; Sohn, Snag Kyun; Lee, Jong Kee; Jun, Soo Han; Lee, Kyu Bo [College of Medicine, Kyungpook National Univ., Taegu (Korea, Republic of); Chung, June Key [College of Medicine, Seoul National Univ., Seoul (Korea, Republic of)

    1999-02-01

    To determine whether {sup 99m}Tc-MIBI is recognized by the multidrug resistant P-glycoprotein (Pgp), we have measured quantitatively {sup 99m}Tc-MIBI uptake in cancer cells. The effects of various Pgp reversing agents on cellular {sup 99m}Tc-MIBI uptake were also investigated in the presence of multidrug resistance gene-1 (mdr 1 gene) overexpression. We measured percentage uptake of {sup 99m}Tc-MIBI at different incubation temperatures both in mdr1 positive and negative cells. The effects of verapamil, cyclosporin, and dipyridamole on cellular uptake of {sup 99m}Tc-MIBI were also evaluated with or without overexpression of mdr1 gene in cultured murine leukemia L1210 cells. The mdr1 gene expressing cell lines were effectively induced in in vitro with continuous application of low-dose adriamycin or vincristine. Cellular uptake of {sup 99m}Tc-MIBI was higher in mdr1 negative L1210 cells than those of mdr1 positive cells, and higher when incubated in 37 .deg. C than 4 .deg. C. In the presence of verapamil, cyclosporin or dipyridamole, {sup 99m}Tc-MIBI uptake was increased upto 604% in mdr1 positive cells. Cellular uptake of {sup 99m}Tc-MIBI is lower in leukemia cells over-expressing mdr1 gene, and MDR-reversing agents increase cellular uptake. These results suggest the {sup 99m}Tc-MIBI can be used for characterizing Pgp expression and developing MDR-reversing agents in vitro.

  7. Effect of ionizing radiation on transcription of colorectal cancer MDR1 gene of HCT-8 cells

    Institute of Scientific and Technical Information of China (English)

    Xiao-Feng Li; Lin Ma; Jing Lu; Li-Xia Kong; Xiao-Hua Long; Su-Huan Liao; Bao-Rong Chi

    2013-01-01

    Objective: To discuss effect of ionizing radiation on transcription of colorectal cancer multidrug resistance (MDR) 1 gene of HCT-8 cells. Methods: Total RNA was extracted by guanidine thiocyanate one-step method. Northern blot was applied to detect transcription level of MDR1 gene. The expression of P-gp protein was detected by flow cytometry. Results: The expression of MDR1 of normal colorectal cancer HCT-8 cells was low. It was increased by 8.35 times under stimulus with 2 Gy. When treated with low doses in advance, high expressed MDR was decreased significantly under 0.05, 0.1 Gy, which was 69.00%, 62.89% in 2 Gy group and 5.77 times, 5.25 times in sham irradiation group. No obvious difference was detected between (0.2+2) Gy group and 2 Gy group. Compared with sham irradiation group, the percentage of P-gp positive cells after radiation of a high 2 Gy dose was increased significantly (P<0.01). When treated with high radiation dose following low radiation dose (0.05 Gy, 0.1 Gy) in advance, the percentage of P-gp positive cells were also increased significantly. The percentage of P-gp positive cells were increased obviously in 0.2 Gy and 2 Gy groups. Compared with simple high radiation 2 Gy group, the percentage of P-gp positive cells was decreased significantly (P<0.05). Conclusions:Low radiation dose can reverse multidrug resistance of colorectal cancer cells caused by high radiation dose.

  8. The importance of MDR1 gene polymorphisms for tacrolimus dosage.

    Science.gov (United States)

    Kravljaca, Milica; Perovic, Vladimir; Pravica, Vera; Brkovic, Voin; Milinkovic, Marija; Lausevic, Mirjana; Naumovic, Radomir

    2016-02-15

    Polymorphisms of the multi drug resistance (MDR1) gene cause variability in P-glycoprotein mediated metabolism of tacrolimus. The aim of this study was to examine the relationship between MDR1 gene single nucleotide polymorphisms (SNPs) and their haplotypes with dosage of tacrolimus in kidney transplant recipients who were cytochrome (CYP) 3A5*3 homozygotes. This study included 91 kidney transplant recipients followed two years after transplantation. Detection and analysis of MDR1 gene polymorphisms in positions C1236T, G2677T/A and C3435T were performed using PCR method. Patients with variant alleles for SNPs G2677T/A and C3435T required higher doses of tacrolimus and had a lower level/dose (L/D) ratio than patients with wild alleles or heterozygotes. That difference was the most obvious for SNP G2677T/A where TT homozygotes required significantly higher doses of tacrolimus during whole follow-up. Their L/D was significantly lower in the first month after transplantation. Recipients with CTT/TTT haplotype also had lower L/D than those with CGC/TTT and CGC/CGC, significantly in the 10th and 20th days after transplantation respectively (p<0.05). Our results demonstrate that TT homozygotes at positions G2677T/A and C3435T required a higher tacrolimus dose than those with wild alleles or heterozygotes. It may be helpful in the prevention of tacrolimus nephrotoxicity early after transplantation. PMID:26705892

  9. Bullatacin Triggered ABCB1-Overexpressing Cell Apoptosis via the Mitochondrial-Dependent Pathway

    Directory of Open Access Journals (Sweden)

    Yong-Ju Liang

    2009-01-01

    Full Text Available This paper was to explore bullatacin-mediated multidrug-resistant cell apoptosis at extremely low concentration. To investigate its precise mechanisms, the pathway of cell apoptosis induced by bullatacin was examined. Bullatacin causes an upregulation of ROS and a downregulation of ΔΨm in a concentration-dependent manner in ABCB1-overexpressing KBv200 cells. In addition, cleavers of caspase-9, caspase-3, and PARP were observed following the release of cytochrome c from mitochondria after bullatacin treatment. However, neither cleavage of caspase-8 nor change of expression level of bcl-2, bax and Fas was observed by the same treatment. Pretreating KBv200 cells with N-acetylcysteine, an antioxidant modulator, resulted in a significant reduction of ROS generation and cell apoptosis induced by bullatacin. Bullatacin-induced apoptosis was antagonized by z-LEHD-fmk, a caspase-9 inhibitor, but not by z-IETD-fmk, a caspase-8 inhibitor. These implied that apoptosis of KBv200 cells induced by bullatacin was associated with the mitochondria-dependent pathway that was limited to activation of apical caspase-9.

  10. Association of ABCB1 and ABCG2 single nucleotide polymorphisms with clinical findings and response to chemotherapy treatments in Kurdish patients with breast cancer.

    Science.gov (United States)

    Ghafouri, Houshiyar; Ghaderi, Bayazid; Amini, Sabrieh; Nikkhoo, Bahram; Abdi, Mohammad; Hoseini, Abdolhakim

    2016-06-01

    The possible interaction between gene polymorphisms and risk of cancer progression is very interesting. Polymorphisms in multi-drug resistance genes have an important role in response to anti-cancer drugs. The present study was aimed to evaluate the possible effects of ABCB1 C3435T and ABCG2 C421A single nucleotide polymorphisms on clinical and pathological outcomes of Kurdish patients with breast cancer. One hundred breast cancer patients and 200 healthy controls were enrolled in this case-control study. Clinical and pathological findings of all individuals were reported, and immunohistochemistry staining was used to assess the tissue expression of specific breast cancer proteins. The ABCB1 C3435T and ABCG2 C421 genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism method (PCR-RFLP). The distribution of different genotypes between patient and control groups was only significant for ABCG2 C421A. A allele of ABCG2 C421A polymorphisms were significantly higher in patients than in controls. Patients with AA genotype of ABCG2 C421A were at higher risk of progressing breast cancer. Patients with A allele of ABCG2 had complete response to chemotherapeutic agents. There was no statistically significant association between ABCB1 C3435T and ABCG2 C421A polymorphisms and tissue expression of ER, PR, Her2/neu, and Ki67. The ABCB1 C3435T has no correlation with clinical findings and treatment with chemotherapy drugs. The A allele of ABCG2 C421A may be a risk factor for progression of breast cancer in Kurdish patients. In addition, breast cancer patients with C allele of this polymorphism have weaker response to treatments with anthracyclines and Paclitaxol. PMID:26700668

  11. ABCB1 haplotype and OPRM1 118A > G genotype interaction in methadone maintenance treatment pharmacogenetics

    Directory of Open Access Journals (Sweden)

    Barratt DT

    2012-04-01

    Full Text Available Daniel T Barratt1, Janet K Coller1, Richard Hallinan2, Andrew Byrne2, Jason M White1, David JR Foster3, Andrew A Somogyi1,41Discipline of Pharmacology, School of Medical Sciences, University of Adelaide, Adelaide, South Australia; 2The Byrne Surgery, Specialist Drug and Alcohol Practice, Redfern, New South Wales; 3Division of Health Sciences, Sansom Institute, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia; 4Department of Clinical Pharmacology, Royal Adelaide Hospital, Adelaide, South Australia, AustraliaBackground: Genetic variability in ABCB1, encoding the P-glycoprotein efflux transporter, has been linked to altered methadone maintenance treatment dose requirements. However, subsequent studies have indicated that additional environmental or genetic factors may confound ABCB1 pharmacogenetics in different methadone maintenance treatment settings. There is evidence that genetic variability in OPRM1, encoding the mu opioid receptor, and ABCB1 may interact to affect morphine response in opposite ways. This study aimed to examine whether a similar gene-gene interaction occurs for methadone in methadone maintenance treatment.Methods: Opioid-dependent subjects (n = 119 maintained on methadone (15–300 mg/day were genotyped for five single nucleotide polymorphisms of ABCB1 (61A > G; 1199G > A; 1236C > T; 2677G > T; 3435C > T, as well as for the OPRM1 18A > G single nucleotide polymorphism. Subjects’ methadone doses and trough plasma (R-methadone concentrations (Ctrough were compared between ABCB1 haplotypes (with and without controlling for OPRM1 genotype, and between OPRM1 genotypes (with and without controlling for ABCB1 haplotype.Results: Among wild-type OPRM1 subjects, an ABCB1 variant haplotype group (subjects with a wild-type and 61A:1199G:1236C:2677T:3435T haplotype combination, or homozygous for the 61A:1199G:1236C:2677T:3435T haplotype had significantly lower doses (median ± standard

  12. Impact of ABCB1 variants on neutrophil depression: a prospective study

    DEFF Research Database (Denmark)

    Bergmann, Troels Korshøj; Andersen, Charlotte Brasch; Gréen, Henrik;

    2010-01-01

    hematologic toxicity was registered. Patients carrying one or two variant alleles of ABCB1 C3435T had progressively more pronounced neutrophil decrease at nadir (P-value 0.03). The same association was found for ABCB1 C1236T and G2677T/A with P-values of 0.06 and 0.02. No statistically significant...... a similar result was reported in 18 patients by Sissung et al.(Eur J Cancer 2006;42:2893-6). This novelty has implications for the understanding of myelosuppression in particular and for tailored chemotherapy in general....

  13. Reversal of multidrug resistance in breast cancer MCF-7/ADR cells by h-R3-siMDR1-PAMAM complexes.

    Science.gov (United States)

    Li, Jun; Liu, Jing; Guo, Nana; Zhang, Xiaoning

    2016-09-10

    Multidrug resistance (MDR) among breast cancer cells is the paramount obstacle for the successful chemotherapy. In this study, anti-EGFR antibody h-R3 was designed to self-assembled h-R3-siRNA-PAMAM-complexes (HSPCs) via electrostatic interactions for siRNA delivery. The physicochemical characterization, cell uptake, MDR1 silencing efficiency, cell migration, cell growth and cell apoptosis were investigated. The HSPCs presented lower cytotoxicity, higher cellular uptake and enhanced endosomal escape ability. Also, HSPCs encapsulating siMDR1 knockdowned 99.4% MDR1 gene with up to ∼6 times of enhancement compared to naked siMDR1, increased the doxorubicin accumulation, down-regulated P-glycoprotein (P-gp) expression and suppressed cellular migration in breast cancer MCF-7/ADR cells. Moreover, the combination of anticancer drug paclitaxel (PTX) and siMDR1 loaded HSPCs showed synergistic effect on overcoming MDR, which inhibited cell growth and induced cell apoptosis. This h-R3-mediated siMDR1 delivery system could be a promising vector for effective siRNA therapy of drug resistant breast cancer. PMID:27444552

  14. PET-CT imaging with [18F]-gefitinib to measure Abcb1a/1b (P-gp) and Abcg2 (Bcrp1) mediated drug-drug interactions at the murine blood-brain barrier

    NARCIS (Netherlands)

    Vlaming, M.L.H.; Läppchen, T.; Jansen, H.T.; Kivits, S.; Driel, A. van; Steeg, E. van der; Hoorn, J.W. van der; Sio, C.F.; Steinbach, O.C.; Groot, J. de

    2015-01-01

    Introduction: The efflux transporters P-glycoprotein (P-gp, ABCB1) and breast cancer resistance protein (BCRP, ABCG2) are expressed at the blood-brain barrier (BBB), and can limit the access of a wide range of drugs to the brain. In this study we developed a PET-CT imaging method for non-invasive, q

  15. Polymorphisms in the ABCB1 gene and effect on outcome and toxicity in childhood acute lymphoblastic leukemia

    DEFF Research Database (Denmark)

    Gregers, J; Gréen, H; Christensen, I J;

    2015-01-01

    The membrane transporter P-glycoprotein, encoded by the ABCB1 gene, influences the pharmacokinetics of anti-cancer drugs. We hypothesized that variants of ABCB1 affect outcome and toxicity in childhood acute lymphoblastic leukemia (ALL). We studied 522 Danish children with ALL, 93% of all those e...

  16. HIF-1α inhibition reverses multidrug resistance in colon cancer cells via downregulation of MDR1/P-glycoprotein.

    Directory of Open Access Journals (Sweden)

    Jianfang Chen

    Full Text Available BACKGROUND: Multidrug resistance (MDR is one of the major reasons chemotherapy-based treatments fail. Hypoxia is generally associated with tumor chemoresistance. However, the correlation between the heterodimeric hypoxia-inducible factor-1 (HIF-1 and the multidrug resistance (MDR1 gene/transporter P-glycoprotein (P-gp remains unclear. This study aims to explore the molecular mechanisms of reversing colon cancer MDR by focusing on the target gene HIF-1α. METHODS: A chemotherapeutic sensitivity assay was used to observe the efficiency of MDR reversal in LoVo multicellular spheroids (MCS. The apoptotic level induced by different drugs was examined by flow cytometry (FCM. Binding of HIF-1α to the MDR1 gene promoter was evaluated by Chromatin immunoprecipitation (ChIP. The relationship between HIF-1α/P-gp expression and sensitivity to chemotherapy was analyzed. RESULTS: The sensitivity of LoVo MCS to all four chemotherapy drugs was decreased to varying degrees under hypoxic conditions. After silencing the HIF-1α gene, the sensitivities of LoVo MCS to all four chemotherapy drugs were restored. The apoptotic levels that all the drugs induced were all decreased to various extents in the hypoxic group. After silencing HIF-1α, the apoptosis level induced by all four chemotherapy drugs increased. The expression of HIF-1α and P-gp was significantly enhanced in LoVo MCS after treatment with hypoxia. Inhibiting HIF-1α significantly decreased the expression of MDR1/P-gp mRNA or protein in both the LoVo monolayers and LoVo MCS. The ChIP assay showed that HIF-1α was bound to the MDR1 gene promoter. Advanced colon carcinoma patients with expression of both HIF-1α and P-gp were more resistant to chemotherapy than that with non expression. CONCLUSIONS: HIF-1α inhibition reverses multidrug resistance in colon cancer cells via downregulation of MDR1/P-gp. The expression of HIF-1α and MDR1/P-gp can be used as a predictive marker for chemotherapy resistance

  17. Therapeutic efifcacy and bone marrow protection of the mdr1 gene and over-dose chemotherapy with doxorubicin for rabbits with VX2 hepatocarcinoma

    Institute of Scientific and Technical Information of China (English)

    Yi Wang; Xian-Qing Jin; Shan Wang; Qiao Wang; Qing Luo; Xiao-Ji Luo

    2006-01-01

    BACKGROUND: Malignant tumors are common diseases threatening to the health and life of human being. Clinically, the multidrug resistance of tumor cells and bone marrow depression caused by chemotherapeutic agents are the main obstacles to the treatment of tumors, and both are related to the mdr1 gene. The over expression of the mdr1 gene in tumor cells contributes to the multidrug resistance of malignant tumor cells. With little expression of the mdr1 gene, bone marrow cells particularly susceptible to multidrug resistance-sensitive agents, which cause serious toxicity in bone marrow. This study was undertaken to assess therapeutic efifcacy of transplantation of bone marrow mononuclear cells transferred with the mdr1 gene and over-dose chemotherapy with doxorubicin for VX2 hepatocarcinoma of rabbits. METHODS: The mdr1 gene was transferred into the bone marrow mononuclear cells of rabbits, which was co-cultured with retroviral vector-containing supernatant, and the cells were autotransplanted into a rabbit model with VX2 hepatocarcinoma. After chemotherapy with doxorubicin, the protective effects of the mdr1 gene and therapeutic efifcacy of over-dose chemotherapy were observed. RESULTS:The mdr1 gene was transferred successfully into the bone marrow mononuclear cells, with a transduction efifciency of 35%. After autotransplantation, the mdr1 gene was expressed functionally in bone marrow with a positive rate of 8%, indicating that the gene played an important role in bone marrow protection. The rabbits with VX2 hepatocarcinoma, which had received the mdr1 gene-transduced cells, survived after chemotherapy with a 3-fold dose of adriamycin, and their white blood cell counts were (4.26±1.03)×104/L. Since hepatocarcinoma cells were eradicated, the survival time (97.00±46.75 d) of the rabbits was extended (P CONCLUSIONS:The transferring of the mdr1 gene into bone marrow mononuclear cells could confer chemoprotection to bone marrow, and over-dose chemotherapy could be

  18. Ferrocenyl 2,5-Piperazinediones as Tubulin-Binding Organometallic ABCB1 and ABCG2 Inhibitors Active against MDR Cells.

    Science.gov (United States)

    Wieczorek, Anna; Błauż, Andrzej; Zakrzewski, Janusz; Rychlik, Błażej; Plażuk, Damian

    2016-06-01

    The tubulin-microtubule system is a common target of many anticancer drugs. However, the use of chemotherapeutics frequently leads to the development of a clinically relevant phenomenon of multidrug resistance (MDR). One of the basic mechanisms involved in MDR involves elevated expression and/or activity of several ATP-binding cassette superfamily members (ABC transporters) which are normally responsible for the efflux of xenobiotics or secondary metabolites outside the cell. Here we present the synthesis and biological characteristics of ferrocenyl analogues of plinabulin, i.e. one of the so-called "spindle poisons". We found that replacement of the phenyl group of plinabulin by the ferrocenyl moiety turns this compound into a potent inhibitor of ABCB1 and ABCG2, thus making it possible to overcome the multidrug resistance phenomenon. We also demonstrated that the alkyl group attached to the imidazole moiety of ferrocenyl analogues of plinabulin strongly affects their potency to inhibit tubulin polymerization. PMID:27326336

  19. Multidrug resistance of DNA-mediated transformants is linked to transfer of the human mdr1 gene.

    OpenAIRE

    Shen, D. W.; Fojo, A; Roninson, I B; Chin, J E; Soffir, R; Pastan, I; Gottesman, M M

    1986-01-01

    Mouse NIH 3T3 cells were transformed to multidrug resistance with high-molecular-weight DNA from multidrug-resistant human KB carcinoma cells. The patterns of cross resistance to colchicine, vinblastine, and doxorubicin hydrochloride (Adriamycin; Adria Laboratories Inc.) of the human donor cell line and mouse recipients were similar. The multidrug-resistant human donor cell line contains amplified sequences of the mdr1 gene which are expressed at high levels. Both primary and secondary NIH 3T...

  20. Ursolic acid sensitized colon cancer cells to chemotherapy under hypoxia by inhibiting MDR1 through HIF-1α*

    Science.gov (United States)

    Shan, Jian-zhen; Xuan, Yan-yan; Zhang, Qi; Huang, Jian-jin

    2016-01-01

    Objective: To explore the efficacy of ursolic acid in sensitizing colon cancer cells to chemotherapy under hypoxia and its underlying mechanisms. Methods: Three colon cancer cell lines (RKO, LoVo, and SW480) were used as in vitro models. 5-Fluorouracil (5-FU) and oxaliplatin were used as chemotherapeutic drugs. Cell viability and apoptosis were tested to evaluate the sensitivity of colon cancer cells to chemotherapy. The transcription and expression levels of hypoxia-inducible factor-1α (HIF-1α), multidrug resistance gene 1 (MDR1), and vascular endothelial growth factors (VEGF) were assessed by quantitative real-time polymerase chain reaction (qRT-PCR) and immunoblotting. Cycloheximide and MG132 were used to inhibit protein synthesis and degradation, respectively. In vitro tube formation assay was used to evaluate angiogenesis. Results: We demonstrated the chemosensitizing effects of ursolic acid with 5-FU and oxaliplatin in three colon cancer cell lines under hypoxia. This effect was correlated to its inhibition of MDR1 through HIF-1α. Moreover, ursolic acid was capable of inhibiting HIF-1α accumulation with little effects on its constitutional expression in normoxia. In addition, ursolic acid also down-regulated VEGF and inhibited tumor angiogenesis. Conclusions: Ursolic acid exerted chemosensitizing effects in colon cancer cells under hypoxia by inhibiting HIF-1α accumulation and the subsequent expression of the MDR1 and VEGF. PMID:27604859

  1. The siRNA targeted to mdr1b and mdr1a mRNAs in vivo sensitizes murine lymphosarcoma to chemotherapy

    OpenAIRE

    Vlassov Valentin V; Nikolin Valery P; Kaledin Vasily I; Popova Nelly A; Mironova Nadezda L; Patutina Olga A; Zenkova Marina A

    2010-01-01

    Abstract Background One of the main obstacles for successful cancer polychemotherapy is multiple drug resistance phenotype (MDR) acquired by tumor cells. Currently, RNA interference represents a perspective strategy to overcome MDR via silencing the genes involved in development of this deleterious phenotype (genes of ABC transporters, antiapoptotic genes, etc.). Methods In this study, we used the siRNAs targeted to mdr1b, mdr1a, and bcl-2 mRNAs to reverse the MDR of tumors and increase tumor...

  2. The biology of MDR1-P-glycoprotein (MDR1-Pgp in designing functional antibody drug conjugates (ADCs: the experience of gemtuzumab ozogamicin

    Directory of Open Access Journals (Sweden)

    Maurizio Cianfriglia

    2013-06-01

    Full Text Available BACKGROUND: The treatment of cancer remains a formidable challenge owing to the difficulties in differentiating tumor cells from healthy cells to ameliorate the disease without causing intolerable toxicity to patients. In addition, the emergence of MDR1-Pgp mediated multi-drug resistance (MDR it is a biological phenomenon that inhibits the curative potential of chemotherapeutic treatments. One way to improve the selectivity of therapeutic molecules in tumors would be to target them on the tumor site, thereby sparing normal tissues. AIMS: In this overview, we will discuss the biological factors influencing the safety and efficacy of the humanized mAb hP67.6 linked to the potent cytotoxic drug calicheamicin-gamma1 (gemtuzumab ozogamicin that target CD33 cell surface antigen expressed on AML cells. In addition, we highlight key aspects of MDR1-Pgp biology as a platform to understand its functional role in gemtuzumab ozogamicin immunotherapy which is tightly linked to an accurate assessment of the MDR status of AML cells. DISCUSSION: Several factors may affect the efficacy and safety of immunoconjugates. These include the common issues of chemical and antibody therapeutics such as specificity, heterogeneous target antigen expression and the complex pharmacokinetics profile of conveyed antibody. Further, the delivered drug may not be sufficient for providing therapeutic benefit, since the curative cytotoxic compound may be affected by intrinsic or acquired resistance of target cells. These and other potential problems, as well as the possible ways to overcome them will be discussed in this review by examining the biological factors involved in safety and efficacy of the first in class antibody drug conjugate (ADC gentuzumab ozogamicin. Despite this set-back, the extensive recorded data and the lessons learned from gentuzumab ozogamicin recently withdrawn from the market for safety concerns helped to pave the way for next generations of clinically

  3. Pilot PET Study to Assess the Functional Interplay Between ABCB1 and ABCG2 at the Human Blood-Brain Barrier.

    Science.gov (United States)

    Bauer, M; Römermann, K; Karch, R; Wulkersdorfer, B; Stanek, J; Philippe, C; Maier-Salamon, A; Haslacher, H; Jungbauer, C; Wadsak, W; Jäger, W; Löscher, W; Hacker, M; Zeitlinger, M; Langer, O

    2016-08-01

    ABCB1 and ABCG2 work together at the blood-brain barrier (BBB) to limit brain distribution of dual ABCB1/ABCG2 substrates. In this pilot study we used positron emission tomography (PET) to assess brain distribution of two model ABCB1/ABCG2 substrates ([(11) C]elacridar and [(11) C]tariquidar) in healthy subjects without (c.421CC) or with (c.421CA) the ABCG2 single-nucleotide polymorphism (SNP) c.421C>A. Subjects underwent PET scans under conditions when ABCB1 and ABCG2 were functional and during ABCB1 inhibition with high-dose tariquidar. In contrast to the ABCB1-selective substrate (R)-[(11) C]verapamil, [(11) C]elacridar and [(11) C]tariquidar showed only moderate increases in brain distribution during ABCB1 inhibition. This provides evidence for a functional interplay between ABCB1 and ABCG2 at the human BBB and suggests that both ABCB1 and ABCG2 need to be inhibited to achieve substantial increases in brain distribution of dual ABCB1/ABCG2 substrates. During ABCB1 inhibition c.421CA subjects had significantly higher increases in [(11) C]tariquidar brain distribution than c.421CC subjects, pointing to impaired cerebral ABCG2 function. PMID:26940368

  4. Pilot PET Study to Assess the Functional Interplay Between ABCB1 and ABCG2 at the Human Blood–Brain Barrier

    Science.gov (United States)

    Bauer, M; Römermann, K; Karch, R; Wulkersdorfer, B; Stanek, J; Philippe, C; Maier‐Salamon, A; Haslacher, H; Jungbauer, C; Wadsak, W; Jäger, W; Löscher, W; Hacker, M; Zeitlinger, M

    2016-01-01

    ABCB1 and ABCG2 work together at the blood–brain barrier (BBB) to limit brain distribution of dual ABCB1/ABCG2 substrates. In this pilot study we used positron emission tomography (PET) to assess brain distribution of two model ABCB1/ABCG2 substrates ([11C]elacridar and [11C]tariquidar) in healthy subjects without (c.421CC) or with (c.421CA) the ABCG2 single‐nucleotide polymorphism (SNP) c.421C>A. Subjects underwent PET scans under conditions when ABCB1 and ABCG2 were functional and during ABCB1 inhibition with high‐dose tariquidar. In contrast to the ABCB1‐selective substrate (R)‐[11C]verapamil, [11C]elacridar and [11C]tariquidar showed only moderate increases in brain distribution during ABCB1 inhibition. This provides evidence for a functional interplay between ABCB1 and ABCG2 at the human BBB and suggests that both ABCB1 and ABCG2 need to be inhibited to achieve substantial increases in brain distribution of dual ABCB1/ABCG2 substrates. During ABCB1 inhibition c.421CA subjects had significantly higher increases in [11C]tariquidar brain distribution than c.421CC subjects, pointing to impaired cerebral ABCG2 function. PMID:26940368

  5. Pharmacogenetic evaluation of ABCB1, Cyp2C9, Cyp2C19 and methylene tetrahydrofolate reductase polymorphisms in teratogenicity of anti-epileptic drugs in women with epilepsy

    Directory of Open Access Journals (Sweden)

    Manna Jose

    2014-01-01

    Full Text Available Aim: Pregnancy in women with epilepsy (WWE who are on anti-epileptic drugs (AEDs has two- to three-fold increased risk of fetal malformations. AEDs are mostly metabolized by Cyp2C9, Cyp2C19 and Cyp3A4 and transported by ABCB1. Patients on AED therapy can have folate deficiency. We hypothesize that the polymorphisms in ABCB1, Cyp2C9, Cyp2C19 and methylene tetrahydrofolate reductase (MTHFR might result in differential expression resulting in differential drug transport, drug metabolism and folate metabolism, which in turn may contribute to the teratogenic impact of AEDs. Materials and Methods: The ABCB1, Cyp2C9, Cyp2C19 and MTHFR polymorphisms were genotyped for their role in teratogenic potential and the nature of teratogenecity in response to AED treatment in WWE. The allelic, genotypic associations were tested in 266 WWE comprising of 143 WWE who had given birth to babies with WWE-malformation (WWE-M and 123 WWE who had normal offsprings (WWE-N. Results: In WWE-M, CC genotype of Ex07 + 139C/T was overrepresented (P = 0.0032 whereas the poor metabolizer allele FNx012 and FNx012 FNx012 genotype of CYP2C219 was significantly higher in comparison to WWE-N group (P = 0.007 and P = 0.005, respectively. All these observations were independent of the nature of malformation (cardiac vs. non cardiac malformations. Conclusion: Our study indicates the possibility that ABCB1 and Cyp2C19 may play a pivotal role in the AED induced teratogenesis, which is independent of nature of malformation. This is one of the first reports indicating the pharmacogenetic role of Cyp2C19 and ABCB1 in teratogenesis of AED in pregnant WWE.

  6. Gene expression profiling in chemoresistant variants of three cell lines of different origin

    DEFF Research Database (Denmark)

    Johnsson, Anders; Vallon-Christensson, Johan; Strand, Carina;

    2005-01-01

    BACKGROUND: Drug resistance is a major problem in clinical cancer chemotherapy. Several mechanisms of resistance have been identified, but the underlying genomic changes are still poorly understood. MATERIALS AND METHODS: Gene expression profiling, using cDNA microarray, was performed in eight cell...... lines (K562 leukemia, MCF-7 breast cancer and S1 colon cancer) with acquired resistance against five cytostatic drugs; daunorubicin (DNR), doxorubicin (DOX), vincristine (VCR), etoposide (VP) and mitoxantrone (MX). RESULTS: The resistant cell lines clustered together based on their type of origin....... Several genes encoding ABC transporters were highly up-regulated, most notably ABCB1 (MDR1) and ABCB4 in several cell lines and ABCG2 (MXR) specifically in MX-resistant cell lines. A pronounced down-regulation of several histones was noted in the MCF-7-derived resistant sublines. Altered expression was...

  7. Chitosan/pshRNA Plasmid Nanoparticles Targeting MDR1 Gene Reverse Paclitaxel Resistance in Ovarian Cancer Cells

    Institute of Scientific and Technical Information of China (English)

    Yan YANG; Zehua WANG; Minfang LI; Shi LU

    2009-01-01

    In order to investigate the effect of chitosan/pshR.NA plasmid nanoparticles targeting MDRI genes on the resistance of A2780/TS cells to paclitaxel,chitosan/pshRNA plasmid nanoparticles were synthesized by means of a complex coacervation technique and transfected into A2780/TS cells.The cells transfected with MDR1-targeted chitosan/pshRNA plasmid nanoparticles were experimental cells and the cells transfected with chitosan/pGPU6/GFP/Neo no-load plasmid nanoparticles served as negative control cells.Morphological features of the nanoparticles were observed under transmission electron microscope (TEM).MDR1 mRNA expression was assessed by RT-PCR.Half-inhibitory concentration (IC50) of paclitaxel for A2780/TS cells was determined by MTT method.TEM showed that the nanoparticles were round-shaped,smooth in surface and the diameters varied from 80 to 120 nm.The MDR1 mRNA in the transfected cells was significantly decreased by 17.6%,27.8% and 52.6% on the post-transfection day 2,4 and 7 when compared with that in A2780/TS cells control (P<0.05).MTT assay revealed that the relative reversal efficiency was increased over time and was 29.6%,51.2% and 61.3% respectively in the transfected cells 2,4,7 days after transfection and IC50 (0.197±0.003,0.144±0.001,0.120±0.004) were decreased with difference being significant when compared with that in A2780/TS (0.269±0.003) cells control (P<0.05).It was concluded that chitosan/pshRNA plasmid nanoparticles targeting MDR1 can effectively reverse the paclitaxel resistance in A2780/TS cells in a time-dependent manner.

  8. Globally prevalent PfMDR1 mutations modulate Plasmodium falciparum susceptibility to artemisinin-based combination therapies.

    Science.gov (United States)

    Veiga, M Isabel; Dhingra, Satish K; Henrich, Philipp P; Straimer, Judith; Gnädig, Nina; Uhlemann, Anne-Catrin; Martin, Rowena E; Lehane, Adele M; Fidock, David A

    2016-01-01

    Antimalarial chemotherapy, globally reliant on artemisinin-based combination therapies (ACTs), is threatened by the spread of drug resistance in Plasmodium falciparum parasites. Here we use zinc-finger nucleases to genetically modify the multidrug resistance-1 transporter PfMDR1 at amino acids 86 and 184, and demonstrate that the widely prevalent N86Y mutation augments resistance to the ACT partner drug amodiaquine and the former first-line agent chloroquine. In contrast, N86Y increases parasite susceptibility to the partner drugs lumefantrine and mefloquine, and the active artemisinin metabolite dihydroartemisinin. The PfMDR1 N86 plus Y184F isoform moderately reduces piperaquine potency in strains expressing an Asian/African variant of the chloroquine resistance transporter PfCRT. Mutations in both digestive vacuole-resident transporters are thought to differentially regulate ACT drug interactions with host haem, a product of parasite-mediated haemoglobin degradation. Global mapping of these mutations illustrates where the different ACTs could be selectively deployed to optimize treatment based on regional differences in PfMDR1 haplotypes. PMID:27189525

  9. Effect of MDR1 gene polymorphisms on mortality in paraquat intoxicated patients

    Science.gov (United States)

    Kim, Hak Jae; Kim, Hyung-Ki; Kwon, Jun-Tack; Lee, Sun-hyo; el Park, Sam; Gil, Hyo-Wook; Song, Ho-yeon; Hong, Sae-yong

    2016-01-01

    Paraquat is a fatal herbicide following acute exposure. Previous studies have suggested that multidrug resistance protein 1 (MDR1) might help remove paraquat from the lungs and the kidney. MDR1 single-nucleotide polymorphisms (SNPs) are involved in the pharmacokinetics of many drugs. The purpose of this study was to determine whether MDR1 SNPs were associated with the mortality in paraquat intoxicated patients. We recruited 109 patients admitted with acute paraquat poisoning. They were genotyped for C1236T, G2677T/A, and C3435T single-nucleotide polymorphisms (SNPs) of MDR1 gene. Their effects on mortality of paraquat intoxicated patients were evaluated. Overall mortality rate was 66.1%. Regarding the C1236T of the MDR1 gene polymorphism, 21 (19.3%) had the wild type MDR1 while 88 (80.7%) had homozygous mutation. Regarding the C3435T MDR1 gene polymorphism, 37(33.9%) patients had the wild type, 23 (21.1%) had heterozygous mutation, and 49 (45.0%) had homozygous mutation. Regarding the G2677T/A MDR1 gene polymorphism, 38 (34.9%) patients had the wild type, 57 (52.3%) had heterozygous mutation, and 14 (12.8%) had homozygous mutation. None of the individual mutations or combination of mutations (two or three) of MDR1 SNP genotypes altered the morality rate. The mortality rate was not significantly different among SNP groups of patients with MDR1 SNPs have no effect on the mortality rate of paraquat intoxicated patients. PMID:27545861

  10. In vitro detection of mdr1 mRNA in murine leukemia cells with {sup 111}In-labeled oligonucleotide

    Energy Technology Data Exchange (ETDEWEB)

    Bai Jingming; Yokoyama, Kunihiko; Kinuya, Seigo; Michigishi, Takatoshi; Tonami, Norihisa [Kanazawa University Graduate School of Medical Sciences, Department of Biotracer Medicine (Nuclear Medicine), Kanazawa (Japan); Shiba, Kazuhiro [Kanazawa University, Radioisotope Center, Kanazawa (Japan); Matsushita, Ryo [Kanazawa University, Laboratory for Development of Medicine, Faculty of Pharmaceutical Sciences, Kanazawa (Japan); Nomura, Masaaki [Kanazawa University Hospital, Hospital Pharmacy, Kanazawa (Japan)

    2004-11-01

    The feasibility of intracellular mdr1 mRNA expression detection with radiolabeled antisense oligonucleotide (ODN) was investigated in the murine leukemia cell line, P388/S, and its subclonal, adriamycin-resistant cell line, P388/R. The expression level of mdr1 mRNA was analyzed by reverse transcription-polymerase chain reaction (RT-PCR). Existence of the multidrug resistance (MDR) phenomenon was assessed via cellular uptake of {sup 99m}Tc-sestamibi (MIBI), a known substrate for P-glycoprotein. A 15-mer phosphorothioate antisense ODN complementary to the sequences located at -1 to 14 of mdr1 mRNA and its corresponding sense ODN were conjugated with the cyclic anhydride of diethylene triamine penta-acetic acid (cDTPA) via an amino group linked to the terminal phosphate at the 5' end at pH 8-9. The DTPA-ODN complexes at concentrations of 0.1-17.4 {mu}Mwere reacted with {sup 111}InCl{sub 3} at pH 5 for 1 h. The hybridization affinity of labeled ODN was evaluated with size-exclusion high-performance liquid chromatography following incubation with the complementary sequence. Cellular uptake of labeled ODN was examined in vitro. Furthermore, enhancing effects of synthetic lipid carriers (Transfast) on transmembrane delivery of ODN were assessed. P388/R cells displayed intense mdr1 mRNA expression in comparison with P388/S cells. {sup 99m}Tc-MIBI uptake in P388/S cells was higher than that in P388/R cells. Specific radioactivity up to 1,634 MBq/nmol was achieved via elevation of added radioactivity relative to ODN molar amount. The hybridization affinity of antisense {sup 111}In-ODN was preserved at approximately 85% irrespective of specific activity. Cellular uptake of antisense {sup 111}In-ODN did not differ from that of sense {sup 111}In-ODN in either P388/S cells or P388/R cells. However, lipid carrier incorporation significantly increased transmembrane delivery of {sup 111}In-ODN; moreover, specific uptake of antisense {sup 111}In-ODN was demonstrated in P388/R

  11. ABCB1 genotypes and haplotypes in patients with dementia and age-matched non-demented control patients

    Directory of Open Access Journals (Sweden)

    Frankfort Suzanne V

    2006-09-01

    Full Text Available Abstract Amyloid β is an in vitro substrate for P-glycoprotein (P-gp, an efflux pump at the blood brain barrier (BBB. The Multi Drug Resistance (ABCB1 gene, encoding for P-gp, is highly polymorphic and this may result in a changed function of P-gp and may possibly interfere with the pathogenesis of Alzheimer's disease. This study investigates to what extent ABCB1 Single Nucleotide Polymorphisms (SNPs; C1236T in exon 12, G2677T/A in exon 21 and C3435T in exon 26 and inferred haplotypes exist in an elderly population and if these SNPs and haplotypes differ between patients with dementia and age-matched non-demented control patients. ABCB1 genotype, allele and haplotype frequencies were neither significantly different between patients with dementia and age-matched controls, nor between subgroups of different types of dementia nor age-matched controls. This study shows ABCB1 genotype frequencies to be comparable with described younger populations. To our knowledge this is the first study on ABCB1 genotypes in dementia. ABCB1 genotypes are presently not useful as a biomarker for dementia, as they were not significantly different between demented patients and age-matched control subjects.

  12. The siRNA targeted to mdr1b and mdr1a mRNAs in vivo sensitizes murine lymphosarcoma to chemotherapy

    Directory of Open Access Journals (Sweden)

    Vlassov Valentin V

    2010-05-01

    Full Text Available Abstract Background One of the main obstacles for successful cancer polychemotherapy is multiple drug resistance phenotype (MDR acquired by tumor cells. Currently, RNA interference represents a perspective strategy to overcome MDR via silencing the genes involved in development of this deleterious phenotype (genes of ABC transporters, antiapoptotic genes, etc.. Methods In this study, we used the siRNAs targeted to mdr1b, mdr1a, and bcl-2 mRNAs to reverse the MDR of tumors and increase tumor sensitivity to chemotherapeutics. The therapy consisting in ex vivo or in vivo application of mdr1b/1a siRNA followed by cyclophosphamide administration was studied in the mice bearing RLS40 lymphosarcoma, displaying high resistance to a wide range of cytostatics. Results Our data show that a single application of mdr1b/1a siRNA followed by treatment with conventionally used cytostatics results in more than threefold decrease in tumor size as compared with the control animals receiving only cytostatics. Conclusions In perspective, mdr1b/1a siRNA may become a well-reasoned adjuvant tool in the therapy of MDR malignancies.

  13. Importancia pronóstica de la expresión de MDR-1 en la leucemia mieloblástica aguda

    Directory of Open Access Journals (Sweden)

    J. Arbelbide

    2003-08-01

    Full Text Available Una proporción importante de pacientes con leucemia mieloblástica aguda (LMA presentan recaída o resistencia con el tratamiento. Uno de los mecanismos involucrados en la resistencia a drogas, es la presencia de la glicoproteína P 170 (gp-P 170 resultante de la expresión del gen MDR-1 sobre las células leucémicas. El objetivo de este trabajo es valorar el impacto pronóstico de la expresión de MDR-1 en una población de pacientes tratados por LMA. Se evaluó retrospectivamente la expresión de MDR-1 en una cohorte de 55 pacientes con LMA, mayores de 16 años, que recibieron tratamiento quimioterápico desde 1990 hasta el 2000. Se evaluó sobre biopsia de médula ósea, la expresión de MDR-1/gp-P 170 por inmunohistoquímica. Mediante una curva ROC, se estableció que una expresión de MDR-1 > 50% en células blásticas, resultó significativa para el logro de remisión completa. Esta expresión de MDR-1+ correlacionó con la presencia de leucocitosis: (p:0.002, expresion de células CD34+ (p:0.006, menor tasa de remisión completa (p:0.001, mayor tasa de recaída (p:0.02 y de estudios citogenéticos no favorables (p:0.02. La SLE fue de 21.2% ES:9.3 con un seguimiento de 22 meses para el grupo MDR-1+ versus 56.4% ES:12.5 con un seguimiento de 78 meses en los casos MDR-1- (p:0.007. Se puede concluir que la expresion de MDR-1 ha demostrado ser un factor pronóstico de resistencia a la quimioterapia. Estos pacientes presentan una menor tasa de remisión completa, una mayor tasa de recaída por persistencia de enfermedad residual post-tratamiento, lo que produce una menor sobrevida global.An important number of patients with Acute Myeloid Leukemia (AML experience relapse or resistance to chemotherapy. One of the mechanisms involved in this resistance is the presence of glycoprotein P170 (gp-P 170, which results of the MDR-1 gene in leukemic cells. The objective of this article is to assess the prognostic impact of the expression of MDR-1 in a

  14. P-Glycoprotein (Abcb1) is involved in absorptive drug transport in skin

    OpenAIRE

    Ito, Katsuaki; Nguyen, Hai Thien; Kato, Yukio; Wakayama, Tomohiko; Kubo, Yoshiyuki; Iseki, Shoichi; Tsuji, Akira

    2008-01-01

    The purpose of the present study was to investigate the role of P-glycoprotein (P-gp) in drug disposition in skin. The distribution of P-gp substrates (rhodamine 123 and itraconazole) to the skin after administration from the epidermal side was lower in P-gp gene knockout (mdr1a/1b-/-) mice than that in wild-type mice. Coadministration of propranolol, a P-gp inhibitor, decreased the distribution of itraconazole to the skin in wild-type mice, but not in mdr1a/1b-/- mice. These results suggest ...

  15. P-Glycoprotein (Abcb1) is involved in absorptive drug transport in skin

    OpenAIRE

    Ito, Katsuaki; Nguyen, Hai Thien; Kato, Yukio; Wakayama, Tomohiko; Kubo, Yoshiyuki; Iseki, Shoichi; Tsuji, Akira

    2008-01-01

    The purpose of the present study was to investigate the role of P-glycoprotein (P-gp) in drug disposition in skin. The distribution of P-gp substrates (rhodamine 123 and itraconazole) to the skin after administration from the epidermal side was lower in P-gp gene knockout (mdr1a/1b-/- ) mice than that in wild-type mice. Coadministration of propranolol, a P-gp inhibitor, decreased the distribution of itraconazole to the skin in wild-type mice, but not in mdr1a/1b-/- mice. These results suggest...

  16. hsa-miRNA27a和hsa-miRNA451通过调控MDRl/P-gp的表达和功能参与卵巢癌和乳腺癌细胞耐药%Expressions of miRNA27a and miRNA451 in ovarian cancer and breast cancer cells and its correlation with drug resistance by targeting MDR1/P-glycoprotein

    Institute of Scientific and Technical Information of China (English)

    李智敏; 罗喜平; 曾俐琴; 彭秀红; 王意; 王泽华

    2015-01-01

    差异有统计学意义(P<0.05)。MCF-7/ADM细胞转染miRNA451模拟物后,MDR1 mRNA表达明显下降,与转染NC组细胞相比,表达下降(65±12)%,差异有统计学意义(P<0.05);P-gp相对表达量[(31±19)%)]与转染NC组细胞P-gp相对表达量[(83±12)%]相比,下降62%,差异有统计学意义(P<0.05);对阿霉素的敏感性增加,IC50为4.61μmol/L,与转染NC组细胞IC50(26μmol/L)相比,差异有统计学意义(P<0.05)。结论:在卵巢癌耐紫杉醇细胞A2780/Taxol和乳腺癌耐阿霉素细胞MCF-7/ADM中,miRNA27a和miRNA451分别异常表达,它们可能分别通过间接或直接作用于MDR1/P-gp,参与肿瘤细胞耐药的发生、发展。%Background and purpose: Resistance of cancer cells to chemotherapy is a major clinical obstacle to successful treatment and leads to poor prognosis for the patients. MicroRNA (miRNA) plays a vital role in tumor cells response to chemotherapeutic agents. This study plans to investigate the expressions of miRNA27a and miRNA451 in ovarian cancer and breast cancer cells and its correlation with drug resistance. Methods:A2780/Taxol cells were established using stepwise selection;Stem-loop quantitative real-time PCR (stem-loop RT-PCR) was used to detect expression of miRNA27a and miRNA451 in ovarian cancer and breast cancer cells. The A2780 and A2780/Taxol cells were transfected with the mimics or inhibitors of miRNA27a or negative control (NC) RNA and the mimics of miRNA451 or NC were transfected into MCF-7/ADM cells by LipofectamineTM 2000. The expression levels of MDR1 mRNA and P-glycoprotein (P-gp) were examined using RT-PCR and Western blot respectively. MTT method was used to analyze drug sensitivity. Results:The expression of miRNA27a was an average of (2.2±0.30) times higher in A2780/Taxol cells than in A2780 cells, with a significant difference between the two groups (P<0.05). The expression of miRNA451 was lower by 84%in MCF-7/ADM cells than in MCF-7 cells, with a signiifcant difference

  17. Inducible and Constitutive Activation of Two Polymorphic Promoter Alleles of the Candida albicans Multidrug Efflux Pump MDR1

    OpenAIRE

    Sasse, Christoph; Schillig, Rebecca; Reimund, Alexandra; Merk, Julia; Morschhäuser, Joachim

    2012-01-01

    Overexpression of the multidrug efflux pump MDR1 confers resistance to the antifungal drug fluconazole on Candida albicans. It has been reported that two types of MDR1 promoters exist in C. albicans and that homozygosity for the allele with higher activity may promote fluconazole resistance. We found that the two MDR1 promoter alleles in strain SC5314 were equally well activated by inducing chemicals or hyperactive forms of the transcription factors Mrr1 and Cap1, which control MDR1 expressio...

  18. High ABCC2 and Low ABCG2 Gene Expression Are Early Events in the Colorectal Adenoma-Carcinoma Sequence

    DEFF Research Database (Denmark)

    Andersen, Vibeke; Vogel, Lotte K.; Kopp, Tine Iskov;

    2015-01-01

    Development of colorectal cancer (CRC) may result from a dysfunctional interplay between diet, gut microbes and the immune system. The ABC transport proteins ABCB1 (P-glycoprotein, Multidrug resistance protein 1, MDR1), ABCC2 (MRP2) and ABCG2 (BCRP) are involved in transport of various compounds...

  19. Association between ABCB1 polymorphisms and haplotypes and Alzheimer's disease: a meta-analysis.

    Science.gov (United States)

    Zhong, Xin; Liu, Ming-Yan; Sun, Xiao-Hong; Wei, Min-Jie

    2016-01-01

    Although several epidemiological studies have investigated the association between ATP-binding cassette subfamily B member 1 (ABCB1) gene polymorphisms and Alzheimer's disease (AD) susceptibility, controversial results exist. Here, we performed a meta-analysis to assess whether ABCB1 polymorphisms 3435C > T (rs1045642), 2677G > T/A (rs2032582), 1236C > T (rs1128503) and haplotypes were associated with AD risk. Nine independent publications were included and analyzed. Crude odds ratio (OR) and 95% confidence interval (CI) were applied to investigate the strength of the association. Sensitivity analysis was conducted to measure the robustness of our analysis. A funnel plot and trim and fill method were used to test and adjust for publication bias. The results showed a significant association between the 3435C > T single nucleotide polymorphism (SNP) and AD susceptibility (CT vs. CC: OR = 1.24, 95% CI = 1.06-1.45, P = 0.01; CT + TT vs. CC: OR = 1.21, 95% CI = 1.04-1.41, P = 0.01) in the total population, as well as in Caucasian subgroup. The 2677G > T/A SNP was related to a decreased AD risk in Caucasian subgroup (TT + TA + AA vs. GT + GA + GG: OR = 0.68, 95% CI = 0.47-0.98, P = 0.04). Moreover, the ABCB1 haplotype analysis showed that the 1236T/2677T/3435C haplotype was associated with a higher risk of AD (OR = 1.99, 95% CI = 1.24-3.18, P = 0.00). Our results suggest that the ABCB1 3435C > T SNP, the 2677G > T/A SNP and 1236T/2677T/3435C haplotype are significantly associated with AD susceptibility. PMID:27600024

  20. PfMDR1: mechanisms of transport modulation by functional polymorphisms.

    Directory of Open Access Journals (Sweden)

    Pedro Eduardo Ferreira

    Full Text Available ATP-Binding Cassette (ABC transporters are efflux pumps frequently associated with multidrug resistance in many biological systems, including malaria. Antimalarial drug-resistance involves an ABC transporter, PfMDR1, a homologue of P-glycoprotein in humans. Twenty years of research have shown that several single nucleotide polymorphisms in pfmdr1 modulate in vivo and/or in vitro drug susceptibility. The underlying physiological mechanism of the effect of these mutations remains unclear. Here we develop structural models for PfMDR1 in different predicted conformations, enabling the study of transporter motion. Such analysis of functional polymorphisms allows determination of their potential role in transport and resistance. The bacterial MsbA ABC pump is a PfMDR1 homologue. MsbA crystals in different conformations were used to create PfMDR1 models with Modeller software. Sequences were aligned with ClustalW and analysed by Ali2D revealing a high level of secondary structure conservation. To validate a potential drug binding pocket we performed antimalarial docking simulations. Using aminoquinoline as probe drugs in PfMDR1 mutated parasites we evaluated the physiology underlying the mechanisms of resistance mediated by PfMDR1 polymorphisms. We focused on the analysis of well known functional polymorphisms in PfMDR1 amino acid residues 86, 184, 1034, 1042 and 1246. Our structural analysis suggested the existence of two different biophysical mechanisms of PfMDR1 drug resistance modulation. Polymorphisms in residues 86/184/1246 act by internal allosteric modulation and residues 1034 and 1042 interact directly in a drug pocket. Parasites containing mutated PfMDR1 variants had a significant altered aminoquinoline susceptibility that appears to be dependent on the aminoquinoline lipophobicity characteristics as well as vacuolar efflux by PfCRT. We previously described the in vivo selection of PfMDR1 polymorphisms under antimalarial drug pressure. Now

  1. Down Regulation of CIAPIN1 Reverses Multidrug Resistance in Human Breast Cancer Cells by Inhibiting MDR1

    Directory of Open Access Journals (Sweden)

    Xuemei Wang

    2012-06-01

    Full Text Available Cytokine-induced apoptosis inhibitor 1 (CIAPIN1, initially named anamorsin, a newly indentified antiapoptotic molecule is a downstream effector of the receptor tyrosine kinase-Ras signaling pathway. Current study has revealed that CIAPIN1 may have wide and important functions, especially due to its close correlations with malignant tumors. However whether or not it is involved in the multi-drug resistance (MDR process of breast cancer has not been elucidated. To explore the effect of CIAPIN1 on MDR, we examined the expression of P-gp and CIAPIN1 by immunohistochemistry and found there was positive correlation between them. Then we successfully interfered with RNA translation by the infection of siRNA of CIAPIN1 into MCF7/ADM breast cancer cell lines through a lentivirus, and the expression of the target gene was significantly inhibited. After RNAi the drug resistance was reduced significantly and the expression of MDR1mRNA and P-gp in MCF7/ADM cell lines showed a significant decrease. Also the expression of P53 protein increased in a statistically significant way (p ≤ 0.01 after RNAi exposure. In addition, flow cytometry analysis reveals that cell cycle and anti-apoptotic enhancing capability of cells changed after RNAi treatment. These results suggested CIAPIN1 may participate in breast cancer MDR by regulating MDR1 and P53 expression, changing cell cycle and enhancing the anti-apoptotic capability of cells.

  2. The search for the mdr1-1Δ mutation of the MDR1 gene in four canine breeds in Uruguay (preliminary study

    Directory of Open Access Journals (Sweden)

    Rosa Gagliardi B.

    2015-01-01

    Full Text Available Objective. The objective of this study is to analyze the frequency of mdr1-1Δ mutation in German Shepherd, Doberman, Border Collie and Greyhound dog breeds in Uruguay. Materials and methods. A total of 95 animals from the four breeds mentioned above were studied. DNA was isolated from blood using potassium acetate with a subsequent degradation from RNA with RNAsaH. The concentration and quality of the DNA obtained was evaluated with a Nanodrop, ND-1000 spectrophotometer. To determine the presence or absence of the mdr1-1Δ mutation, DNA samples were sent to Gene Seek, Neogen Corporation of Chicago, United States, for genotyping. Results. In all 95 animals studied, the mdr1-1Δ mutation was not present. Conclusions. Based on the preliminary results obtained, other elements that may cause adverse drug reactions must be considered: unidentified mutations in other regions of the MDR1 gene; mutations in other genes involved in the transport of drugs from the same subfamily or another; mutations in enzymes involved in drug metabolism (e.g. Cytochrome P450. Moreover, especially with Border Collies and Greyhounds, it is advisable to increase the number of animals in the study.

  3. Multi-drug resistance (MDR1 gene and P-glycoprotein influence on pharmacokinetic and pharmacodymanic of therapeutic drugs

    Directory of Open Access Journals (Sweden)

    Linardi Renata Lehn

    2006-01-01

    Full Text Available (MDR1 gene expressed in tumor cells and also in several normal tissues, such as intestine, liver, kidney, blood-brain barrier, spinal cord, and placenta. P-gp has been identified in mice, rat, bovine, monkey, rodents, and human beings and has been receiving a particular clinical relevance because this protein expression limits brain access and intestinal absorption of many drugs. This protein plays a role as a protective barrier against a wide variety of substrates, avoiding drug entry into the central nervous system. P-glycoprotein also interferes with drug bioavailability and disposition, including absorption, distribution, metabolization, and excretion, influencing pharmacokinetic and pharmacodynamic of drugs. Modulation of P-gp may help the efficacy of treatment of several diseases and can explain some adverse central nervous system effects induced by drugs after intravenous administration and the poor response of oral administration in patients. Alteration in P-gp expression or function has been associated with several diseases susceptibility in humans and animals. Furthermore, additional studies relating MDR1 and P-gp expression has an important clinical implication also in terms of treatment efficacy.

  4. Cytokine-induced killer cells showing multidrug resistance and remaining cytotoxic activity to tumor cells after transfected with mdr1 cDNA

    Institute of Scientific and Technical Information of China (English)

    李惠芳; 杨永红; 石永进; 王逸群; 朱平

    2004-01-01

    Background Routine treatment of cancer such as surgery, radiation or chemotherapy is sometimes unable to erdiacate metastatic malignant cells. So we tried a new method and increased the adoptive immunotherapy of Cytokine-induced killer (CIK) cells in tumor patients and the multidrug resistance (mdr1) cDNA was transfected into CIK cells. Methods CIK cells were obtained from peripheral blood and induced by IFN-γ, anti-CD3 monoclonal antibody, IL-2 and IL-1. CIK cells were transfected with plasmid PHaMDR containing human mdr1 cDNA by electroporation. RT-PCR was used to detect mdr1 mRNA in transfected CIK cells. P-glycoprotein (P-gp) expressed on surface of CIK cells was assayed by FITC-conjugated anti-P-gp monoclonal antibody and flow cytometry. Multidrug resistance to doxorubicin and colchicine and cytotoxic activity to human breast cancer cell line MCF7 were performed using MTT method.Results mdr1 mRNA was detected in transfected CIK cells. P-gp was expressed on the surface of the transfected CIK cells, and the P-gp positive cells reached 21%-37% of the total CIK cells after transfection. The IC50 to doxorubicin increased to 22.3-45.8 times, and that to colchicines to 6.7-11.35 times, as compared to those of untransfected CIK cells. However, the cytotoxic activity to MCF7 cell line remained unaltered.Conclusions CIK cells were successfully transfected with mdr1 cDNA by using electroporation. The transfected CIK cells had the characteristics of multidrug resistance without change in their cytotoxic activity to tumor cells.

  5. Association of single nucleotide polymorphisms of ABCB1, OPRM1 and COMT with pain perception in cancer patients.

    Science.gov (United States)

    Wang, Xu-shi; Song, Hai-bin; Chen, Si; Zhang, Wei; Liu, Jia-qi; Huang, Chao; Wang, Hao-ran; Chen, Yuan; Chu, Qian

    2015-10-01

    Pain perception is influenced by multiple factors. The single nucleotide polymorphisms (SNPs) of some genes were found associated with pain perception. This study aimed to examine the association of the genotypes of ABCB1 C3435T, OPRM1 A118G and COMT V108/158M (valine 108/158 methionine) with pain perception in cancer patients. We genotyped 146 cancer pain patients and 139 cancer patients without pain for ABCB1 C3435T (rs1045642), OPRM1 A118G (rs1799971) and COMT V108/158M (rs4680) by the fluorescent dye-terminator cycle sequencing method, and compared the genotype distribution between groups with different pain intensities by chi-square test and pain scores between groups with different genotypes by non-parametric test. The results showed that in these cancer patients, the frequency of variant T allele of ABCB1 C3435T was 40.5%; that of G allele of OPRM1 A118G was 38.5% and that of A allele of COMT V108/158M was 23.3%. No significant difference in the genotype distribution of ABCB1 C3435T (rs1045642) and OPRM1 A118G (rs1799971) was observed between cancer pain group and control group (P=0.364 and 0.578); however, significant difference occurred in the genotype distribution of COMT V108/158M (rs4680) between the two groups (P=0.001). And the difference could not be explained by any other confounding factors. Moreover, we found that the genotypes of COMT V108/158M and ABCB1 C3435T were associated with the intensities of pain in cancer patients. In conclusion, our results indicate that the SNPs of COMT V108/158M and ABCB1 C3435T significantly influence the pain perception in Chinese cancer patients.

  6. Studies on the Relationship between Multidrug Resistance 1 Gene and Pancreatic Cancer%胰腺癌与mdr1基因的相关性研究

    Institute of Scientific and Technical Information of China (English)

    王百林; 肖震宇; 陈孝平; 翟淑萍

    2004-01-01

    Objective: To study the relationship between the expressions of multidrug-resistance, 1 (mdr1) gene-coded mRNA and its product P-glycoprotein (P-gp) and biological characteristics of tumor cells in patients with previously untreated primary pancreatic cancer (PC) for guiding significance to the clinical treatment. Methods: Expression of mdr1 mRNA and P-gp on paraffin embedded sections was detected by in situ polymerase chain reaction (ISPCR) and immunohistochemistry correspondingly from 150 cases of normal and abnormal pancreatic tissues including 97, 32 and 21 cases of pancreatic cancer, pancreatitisand normal pancreatic tissues respectively. Results: Distributions of positive staining in mdr1 mRNA and P-gp were mainly found on the apical plasma membranes and in cytoplasms of endothelial duct cells in tumor and normal tissues. The positive staining rates of expression of the mdr1 mRNA and P-gp detected in all pancreatic tumors were significantly higher than that in pancreatitis and normal tissues correspondingly (P<0.05). Moreover, higher expressions of mdr1 mRNA and P-gp in tumor cells werecorrelated with some biological characteristics of PC, such as the degree of differentiation, aggressiveness and TNM stage of tumors (P<0.05). However, there was no correlation between the rate of expression of mdr1 mRNA and P-gp and some clinical findings including age, sex, location and tumor size. Conclusion:The expression of mdr1 gene was associated with "natural" multi-drug resistance in PC. There was an important guiding significance between the detection of expression of mdr1 gene and prediction of the sensitivity to chemotherapy of PC. Meanwhile, it probably could be used as one of profoundly parameters to assess the degrees of differentiation and prognosis in PC.%目的通过研究未化疗的原发性胰腺癌mdr1基因mRNA及其蛋白产物P-gp的表达与肿瘤生物学特性的关系,以便指导胰腺癌的临床治疗.方法 应用免疫

  7. Breed distribution of the nt230(del4) MDR1 mutation in dogs.

    Science.gov (United States)

    Gramer, Irina; Leidolf, Regina; Döring, Barbara; Klintzsch, Stefanie; Krämer, Eva-Maria; Yalcin, Ebru; Petzinger, Ernst; Geyer, Joachim

    2011-07-01

    A 4-bp deletion mutation associated with multiple drug sensitivity exists in the canine multidrug resistance (MDR1) gene. This mutation has been detected in more than 10 purebred dog breeds as well as in mixed breed dogs. To evaluate the breed distribution of this mutation in Germany, 7378 dogs were screened, including 6999 purebred and 379 mixed breed dogs. The study included dog breeds that show close genetic relationship or share breeding history with one of the predisposed breeds but in which the occurrence of the MDR1 mutation has not been reported. The breeds comprised Bearded Collies, Anatolian Shepherd Dog, Greyhound, Belgian Tervuren, Kelpie, Borzoi, Australian Cattle Dog and the Irish Wolfhound. The MDR1 mutation was not detected is any of these breeds, although it was found as expected in the Collie, Longhaired Whippet, Shetland Sheepdog, Miniature Australian Shepherd, Australian Shepherd, Wäller, White Swiss Shepherd, Old English Sheepdog and Border Collie with varying allelic frequencies for the mutant MDR1 allele of 59%, 45%, 30%, 24%, 22%, 17%, 14%, 4% and 1%, respectively. Allelic frequencies of 8% and 2% were determined in herding breed mixes and unclassified mixed breeds, respectively. Because of its widespread breed distribution and occurrence in many mixed breed dogs, it is difficult for veterinarians and dog owners to recognise whether MDR1-related drug sensitivity is relevant for an individual animal. This study provides a comprehensive overview of all affected dog breeds and many dog breeds that are probably unaffected on the basis of ∼15,000 worldwide MDR1 genotyping data. PMID:20655253

  8. Arabidopsis TWISTED DWARF1 functionally interacts with Auxin Exporter ABCB1 on the root plasma membrane

    DEFF Research Database (Denmark)

    Wang, Bangjun; Bailly, Aurélien; Zwiewka, Marta;

    2013-01-01

    . In planta bioluminescence resonance energy transfer analysis was used to verify specific ABC transporter B1 (ABCB1)-TWD1 interaction. Our data support a model in which TWD1 promotes lateral ABCB-mediated auxin efflux via protein-protein interaction at the plasma membrane, minimizing reflux from the root...

  9. Epoxylathyrol Derivatives: Modulation of ABCB1-Mediated Multidrug Resistance in Human Colon Adenocarcinoma and Mouse T-Lymphoma Cells.

    Science.gov (United States)

    Matos, Ana M; Reis, Mariana; Duarte, Noélia; Spengler, Gabriella; Molnár, Joseph; Ferreira, Maria-José U

    2015-09-25

    Epoxyboetirane A (1), a macrocyclic diterpene that was found to be inactive as an ABCB1 modulator, was submitted to several chemical transformations, aimed at generating a series of compounds with improved multidrug resistance (MDR)-modifying activity. Overall, 23 new derivatives were prepared, in addition to the already reported epoxylathyrol (2) and methoxyboetirol (3). Their anti-MDR potential was assessed through both functional and chemosensitivity assays on resistant human colon adenocarcinoma and human ABCB1-gene transfected L5178Y mouse lymphoma cells. Structure-activity relationship analysis showed that different substitution patterns led to distinct ABCB1 inhibitory activities, although intrinsic cellular characteristics seemed to influence the modulatory behavior. A considerable enhancement in MDR-modifying activity was observed for aromatic compounds in both cell lines, particularly in 3,17-disubstituted esters derived from 3, a Payne-rearranged Michael adduct of 2. All compounds tested were revealed to interact synergistically with doxorubicin, and ATPase inhibition by three representative MDR-modifying compounds was also investigated. On account of its outstanding ABCB1 inhibitory activity at 0.2 μM and overall remarkable bioactive profile, methoxyboetirane B (22) was found to be a new promising lead for MDR-reversing anticancer drug development. PMID:26331763

  10. VEGF, eNOS, and ABCB1 genetic polymorphisms may increase the risk of osteonecrosis of the femoral head.

    Science.gov (United States)

    Zhou, Z C; Gu, S Z; Wu, J; Liang, Q W

    2015-01-01

    We investigated the associations between vascular endothelial growth factors (VEGF), endothelial nitric oxide synthase (eNOS), and ATP-binding cassette subfamily B member 1 transporter (ABCB1) polymorphisms and the risk of osteonecrosis of the femoral head (ONFH). Published studies were reviewed and analyzed based on predefined selection criteria. The strength of the association between VEGF, eNOS, and ABCB1 polymorphisms and ONFH risk was evaluated based on the odds ratio with corresponding 95%CIs. Meta-analysis was performed using the Comprehensive Meta-analysis 2.0 software. A total of 135 relevant articles were retrieved, of which 10 studies met the selection criteria, and included a total of 1025 patients with ONFH and 1730 healthy controls. The meta-analysis study results revealed that the VEGF rs2010963 G>C polymorphism increased the risk of ONFH, while the VEGF rs2010963 G>C and ABCB1 rs1045642 C>T polymorphisms increased the risk of ONFH under the allele model. In conclusion, the VEGF, eNOS, and ABCB1 polymorphisms may contribute to ONFH, but further studies including larger sample sizes are needed to confirm the results. PMID:26535684

  11. Variants in CDA and ABCB1 are predictors of capecitabine-related adverse reactions in colorectal cancer

    Science.gov (United States)

    García, María I.; García-Alfonso, Pilar; Robles, Luis; Grávalos, Cristina; González-Haba, Eva; Marta, Pellicer; Sanjurjo, María; López-Fernández, Luis A.

    2015-01-01

    Adverse reactions to capecitabine-based chemotherapy limit full administration of cytotoxic agents. Likewise, genetic variations associated with capecitabine-related adverse reactions are associated with controversial results and a low predictive value. Thus, more evidence on the role of these variations is needed. We evaluated the association between nine polymorphisms in MTHFR, CDA, TYMS, ABCB1, and ENOSF1 and adverse reactions, dose reductions, treatment delays, and overall toxicity in 239 colorectal cancer patients treated with capecitabine-based regimens. The ABCB1*1 haplotype was associated with a high risk of delay in administration or reduction in the dose of capecitabine, diarrhea, and overall toxicity. CDA rs2072671 A was associated with a high risk of overall toxicity. TYMS rs45445694 was associated with a high risk of delay in administration or reduction in the dose of capecitabine, HFS >1 and HFS >2. Finally, ENOSF1 rs2612091 was associated with HFS >1, but was a poorer predictor than TYMS rs45445694. A score based on ABCB1-CDA polymorphisms efficiently predicts patients at high risk of severe overall toxicity (PPV, 54%; sensitivity, 43%) in colorectal cancer patients treated with regimens containing capecitabine. Polymorphisms in ABCB1, CDA, ENOSF1,and TYMS could help to predict specific and overall severe adverse reactions to capecitabine. PMID:25691056

  12. HIV-1 integrase inhibitors are substrates for the multidrug transporter MDR1-P-glycoprotein

    Directory of Open Access Journals (Sweden)

    Cara Andrea

    2007-03-01

    Full Text Available Abstract Background The discovery of diketoacid-containing derivatives as inhibitors of HIV-1 Integrase (IN (IN inhibitors, IINs has played a major role in validating this enzyme as an important target for antiretroviral therapy. Since the in vivo efficacy depends on access of these drugs to intracellular sites where HIV-1 replicates, we determined whether the IINs are recognized by the multidrug transporter MDR1-P-glycoprotein (P-gp thereby reducing their intracellular accumulation. To address the effect of IINs on drug transport, nine quinolonyl diketo acid (DKA derivatives active on the HIV-1 IN strand transfer (ST step and with EC50 ranging from 1.83 to >50 μm in cell-based assays were tested for their in vitro interaction with P-gp in the CEM-MDR cell system. IINs were investigated for the inhibition and induction of the P-gp function and expression as well as for multidrug resistance (MDR reversing ability. Results The HIV-1 IINs act as genuine P-gp substrates by inhibiting doxorubicin efflux and inducing P-gp functional conformation changes as evaluated by the modulation of UIC2 mAb epitope. Further, IINs chemosensitize MDR cells to vinblastine and induce P-gp expression in drug sensitive revertants of CEM-MDR cells. Conclusion To our knowledge, this is the first demonstration that HIV-1 IINs are P-gp substrates. This biological property may influence the absorption, distribution and elimination of these novels anti HIV-1 compounds.

  13. Hedgehog Pathway Inhibitor HhAntag691 Is a Potent Inhibitor of ABCG2/BCRP and ABCB1/Pgp

    Directory of Open Access Journals (Sweden)

    Yimao Zhang

    2009-01-01

    Full Text Available HhAntag691 (GDC-0449, a low-molecular weight inhibitor of the tumor-promoting hedgehog (Hh signaling pathway, has been used to treat medulloblastoma in animal models and has recently entered clinical trials for a variety of solid tumors. Here, we show that HhAntag691 inhibits multiple ATP-binding cassette (ABC transporters. ATP-binding cassette transporters are within a family of membrane proteins, the overexpression of which is associated with multidrug resistance, a major impediment to successful cancer treatment. HhAntag691 is a potent inhibitor of two ABC transporters, ABCG2/BCRP and ABCB1/Pgp, and is a mild inhibitor of ABCC1/MRP1. In ABCG2-overexpressing HEK293 cells, HhAntag691 increased retention of the fluorescent ABCG2 substrate BODIPY-prazosin and resensitized these cells to mitoxantrone, an antineoplastic ABCG2 substrate. In Madin-Darby canine kidney II cells engineered to overexpress Pgp or MRP1, HhAntag691 increased the retention of calcein-AM and resensitized them to colchicine. HhAntag691 also resensitized human non-small cell lung carcinoma cells NCI-H460/par and NCI-H460/MX20, which overexpress ABCG2 in response to mitoxantrone, to mitoxantrone, and to topotecan or SN-38. The IC50 values of HhAntag691 for inhibition of ABCG2 and Pgp were ∼1.4 and ∼3.0 µM, respectively. Because ABC transporters are highly expressed at the blood-brain barrier and on many tumor cells, they contribute significantly to treatment failure of many types of cancer, particularly of those within the neuraxis. In addition to its effect on Hh signaling, the ability of HhAntag691 and related compounds to inhibit two key ABC transporters could contribute to their effectiveness in treating malignancies.

  14. The functional influences of common ABCB1 genetic variants on the inhibition of P-glycoprotein by Antrodia cinnamomea extracts.

    Directory of Open Access Journals (Sweden)

    Ming-Jyh Sheu

    Full Text Available Antrodia cinnamomea is a traditional healthy food that has been demonstrated to possess anti-inflammatory, antioxidative, and anticacer effects. The purpose of this study was to evaluate whether the ethanolic extract of A. cinnamomea (EEAC can affect the efflux function of P-glycoprotein (P-gp and the effect of ABCB1 genetic variants on the interaction between EEAC and P-gp. To investigate the mechanism of this interaction, Flp-In™-293 cells stably transfected with various genotypes of human P-gp were established and the expression of P-gp was confirmed by Western blot. The results of the rhodamine 123 efflux assay demonstrated that EEAC efficiently inhibited wild-type P-gp function at an IC50 concentration of 1.51 ± 0.08 µg/mL through non-competitive inhibition. The IC50 concentrations for variant-type 1236T-2677T-3435T P-gp and variant-type 1236T-2677A-3435T P-gp were 5.56 ± 0.49 µg/mL and 3.33±0.67 µg/mL, respectively. In addition, the inhibition kinetics of EEAC also changed to uncompetitive inhibition in variant-type 1236T-2677A-3435T P-gp. The ATPase assay revealed that EEAC was an ATPase stimulator and was capable of reducing verapamil-induced ATPase levels. These results indicate that EEAC may be a potent P-gp inhibitor and higher dosages may be required in subjects carrying variant-types P-gp. Further studies are required to translate this basic knowledge into clinical applications.

  15. Dioscin strengthens the efficiency of adriamycin in MCF-7 and MCF-7/ADR cells through autophagy induction: More than just down-regulation of MDR1.

    Science.gov (United States)

    Wang, Changyuan; Huo, Xiaokui; Wang, Lijuan; Meng, Qiang; Liu, Zhihao; Liu, Qi; Sun, Huijun; Sun, Pengyuan; Peng, Jinyong; Liu, Kexin

    2016-01-01

    The purpose of present study was to investigate the effect of dioscin on activity of adriamycin (ADR) in ADR-sensitive (MCF-7) and ADR-resistant (MCF-7/ADR) human breast cancer cells and to clarify the molecular mechanisms involved. Antiproliferation effect of ADR was enhanced by dioscin in MCF-7 and MCF-7/ADR cells. Dioscin significantly inhibited MDR1 mRNA and protein expression and MDR1 promoter and nuclear factor κ-B (NF-κB) activity in MCF-7/ADR cells. Additionally, inhibitor κB-α (IκB-α) degradation was inhibited by dioscin. Moreover, dioscin induced the formation of vacuoles in the cytoplasm and protein level of LC3-II in MCF-7 and MCF-7/ADR cells. Autophagy inhibitor 3-MA abolished the effect of dioscin on ADR cytotoxicity. Dioscin inhibited phosphorylation of PI3K and Akt, resulting in upregulation of LC3-II expression. In conclusion, dioscin increased ADR chemosensitivity by down-regulating MDR1 expression through NF-κB signaling inhibition in MCF-7/ADR cells. Autophagy was induced by dioscin to ameliorate the cytotoxicity of ADR via inhibition of the PI3K/AKT pathways in MCF-7 and MCF-7/ADR cells. These findings provide evidence in support of further investigation into the clinical application of dioscin as a chemotherapy adjuvant. PMID:27329817

  16. Dioscin restores the activity of the anticancer agent adriamycin in multidrug-resistant human leukemia K562/adriamycin cells by down-regulating MDR1 via a mechanism involving NF-κB signaling inhibition.

    Science.gov (United States)

    Wang, Lijuan; Meng, Qiang; Wang, Changyuan; Liu, Qi; Peng, Jinyong; Huo, Xiaokui; Sun, Huijun; Ma, Xiaochi; Liu, Kexin

    2013-05-24

    The purpose of this study was to investigate the ameliorating effect of dioscin (1) on multidrug resistance (MDR) in adriamycin (ADR)-resistant erythroleukemic cells (K562/adriamycin, K562/ADR) and to clarify the molecular mechanisms involved. High levels of multidrug resistance 1 (MDR1) mRNA and protein and reduced ADR retention were found in K562/ADR cells compared with parental cells (K562). Dioscin (1), a constituent of plants in the genus Discorea, significantly inhibited MDR1 mRNA and protein expression and MDR1 promoter and nuclear factor κ-B (NF-κB) activity in K562/ADR cells. MDR1 mRNA and protein suppression resulted in the subsequent recovery of intracellular drug accumulation. Additionally, inhibitor κB-α (IκB-α) degradation was inhibited by 1. Dioscin (1) reversed ADR-induced MDR by down-regulating MDR1 expression by a mechanism that involves the inhibition of the NF-κB signaling pathway. These findings provide evidence to support the further investigation of the clinical application of dioscin (1) as a chemotherapy adjuvant. PMID:23621869

  17. The search for the mdr1-1Δ mutation of the MDR1 gene in four canine breeds in Uruguay (preliminary study)

    OpenAIRE

    Rosa Gagliardi B.; Diana Martínez A.; Beatriz Tellechea H.; Pedro Sitjar Q.; Silvia Llambí D.; María Arruga L.

    2015-01-01

    Objective. The objective of this study is to analyze the frequency of mdr1-1Δ mutation in German Shepherd, Doberman, Border Collie and Greyhound dog breeds in Uruguay. Materials and methods. A total of 95 animals from the four breeds mentioned above were studied. DNA was isolated from blood using potassium acetate with a subsequent degradation from RNA with RNAsaH. The concentration and quality of the DNA obtained was evaluated with a Nanodrop, ND-1000 spectrophotometer. To determine the pres...

  18. Multiple transport-active binding sites are available for a single substrate on human P-glycoprotein (ABCB1).

    Science.gov (United States)

    Chufan, Eduardo E; Kapoor, Khyati; Sim, Hong-May; Singh, Satyakam; Talele, Tanaji T; Durell, Stewart R; Ambudkar, Suresh V

    2013-01-01

    P-glycoprotein (Pgp, ABCB1) is an ATP-Binding Cassette (ABC) transporter that is associated with the development of multidrug resistance in cancer cells. Pgp transports a variety of chemically dissimilar amphipathic compounds using the energy from ATP hydrolysis. In the present study, to elucidate the binding sites on Pgp for substrates and modulators, we employed site-directed mutagenesis, cell- and membrane-based assays, molecular modeling and docking. We generated single, double and triple mutants with substitutions of the Y307, F343, Q725, F728, F978 and V982 residues at the proposed drug-binding site with cys in a cysless Pgp, and expressed them in insect and mammalian cells using a baculovirus expression system. All the mutant proteins were expressed at the cell surface to the same extent as the cysless wild-type Pgp. With substitution of three residues of the pocket (Y307, Q725 and V982) with cysteine in a cysless Pgp, QZ59S-SSS, cyclosporine A, tariquidar, valinomycin and FSBA lose the ability to inhibit the labeling of Pgp with a transport substrate, [(125)I]-Iodoarylazidoprazosin, indicating these drugs cannot bind at their primary binding sites. However, the drugs can modulate the ATP hydrolysis of the mutant Pgps, demonstrating that they bind at secondary sites. In addition, the transport of six fluorescent substrates in HeLa cells expressing triple mutant (Y307C/Q725C/V982C) Pgp is also not significantly altered, showing that substrates bound at secondary sites are still transported. The homology modeling of human Pgp and substrate and modulator docking studies support the biochemical and transport data. In aggregate, our results demonstrate that a large flexible pocket in the Pgp transmembrane domains is able to bind chemically diverse compounds. When residues of the primary drug-binding site are mutated, substrates and modulators bind to secondary sites on the transporter and more than one transport-active binding site is available for each

  19. Multiple transport-active binding sites are available for a single substrate on human P-glycoprotein (ABCB1.

    Directory of Open Access Journals (Sweden)

    Eduardo E Chufan

    Full Text Available P-glycoprotein (Pgp, ABCB1 is an ATP-Binding Cassette (ABC transporter that is associated with the development of multidrug resistance in cancer cells. Pgp transports a variety of chemically dissimilar amphipathic compounds using the energy from ATP hydrolysis. In the present study, to elucidate the binding sites on Pgp for substrates and modulators, we employed site-directed mutagenesis, cell- and membrane-based assays, molecular modeling and docking. We generated single, double and triple mutants with substitutions of the Y307, F343, Q725, F728, F978 and V982 residues at the proposed drug-binding site with cys in a cysless Pgp, and expressed them in insect and mammalian cells using a baculovirus expression system. All the mutant proteins were expressed at the cell surface to the same extent as the cysless wild-type Pgp. With substitution of three residues of the pocket (Y307, Q725 and V982 with cysteine in a cysless Pgp, QZ59S-SSS, cyclosporine A, tariquidar, valinomycin and FSBA lose the ability to inhibit the labeling of Pgp with a transport substrate, [(125I]-Iodoarylazidoprazosin, indicating these drugs cannot bind at their primary binding sites. However, the drugs can modulate the ATP hydrolysis of the mutant Pgps, demonstrating that they bind at secondary sites. In addition, the transport of six fluorescent substrates in HeLa cells expressing triple mutant (Y307C/Q725C/V982C Pgp is also not significantly altered, showing that substrates bound at secondary sites are still transported. The homology modeling of human Pgp and substrate and modulator docking studies support the biochemical and transport data. In aggregate, our results demonstrate that a large flexible pocket in the Pgp transmembrane domains is able to bind chemically diverse compounds. When residues of the primary drug-binding site are mutated, substrates and modulators bind to secondary sites on the transporter and more than one transport-active binding site is available

  20. Influence of C3435T and G2677T/A MDR1 polymorphism on morphine side effects

    Institute of Scientific and Technical Information of China (English)

    CVERSTUYFT; LCOULBAULT; MBEAUSSIER; HWEICKMANS; PJAILLON; ALIENHARDT; LBECQUEMONT

    2004-01-01

    AIM: Morphine efficacy and side effects present large interindividual pharmacodynamic variability. Single nucleotide polymorphisms (SNPs) of P-glycoprotein (MDR 1), an efflux transporter considered as a major component of the blood-brain-barrier, may explain a part of this variability. We aimed to determine the potential relationships between MDR1 C3435T and

  1. Frequency of the MDR1 mutant allele associated with multidrug sensitivity in dogs from Brazil

    Directory of Open Access Journals (Sweden)

    Monobe MM

    2015-04-01

    Full Text Available Marina M Monobe,1 João P Araujo Junior,2 Kari V Lunsford,3 Rodrigo C Silva,4 Camilo Bulla41Department of Veterinary Clinics, School of Veterinary Medicine and Animal Science, 2Department of Microbiology and Immunology, Biosciences Institute, Sao Paulo State University (UNESP, Botucatu, Brazil; 3Department of Clinical Sciences and Animal Health Center, 4Department of Pathobiology and Population Medicine, College of Veterinary Medicine, Mississippi State University, Mississippi, MS, USAAbstract: To date, a 4-bp deletion in the MDR1 gene has been detected in more than ten dog breeds, as well as in mixed breed dogs, in several countries, however information regarding this mutation in dogs from Brazil is lacking. For this reason, 103 Collies, 77 Border Collies, 76 Shetland Sheepdogs, 20 Old English Sheepdogs, 55 German Shepherds, 16 Australian Shepherds, and 53 Whippets from Brazil were screened for the presence of the mutation. The heterozygous mutated genotype, MDR1 (+/−, frequency found for Collies, Australian Shepherd, and Shetland Sheepdog was 50.5% (95% CI =41.1%–59.9%, 31.3% (95% CI =8.6%–53.2%, and 15.8% (95% CI =7.7%–23.9%, respectively. Homozygous mutated genotype, MDR1 (−/−, was detected only in Collies 35.9%. The MDR1 allele mutant frequency found for Collies, Australian Shepherd, and Shetland Sheepdog was 61.2% (95% CI =54.8%–67.5%, 15.6% (95% CI =3.1%–28.2%, and 7.9% (95% CI =3.7%–12.1%, respectively. Additionally, even free of the mutant allele, the maximum mutant prevalence (MMP in that population, with 95% CI, was 3.8%, 5.2%, 5.4%, and 13.8% for Border Collies, German Shepherds, Whippets, and Old English Sheepdogs, respectively. In this way, this information is important, not only for MDR1 genotype-based breeding programs and international exchange of breeding animals of predisposed breeds, but also for modification of drug therapy for breeds at risk.Keywords: P-glycoprotein, MDR1 mutation, ivermectin, dog, drug

  2. Multidrug-Resistant Transporter Mdr1p-Mediated Uptake of a Novel Antifungal Compound

    OpenAIRE

    Sun, Nuo; Li, Dongmei; Fonzi, William; Xin LI; Zhang, Lixin; Calderone, Richard

    2013-01-01

    The activity of many anti-infectious drugs has been compromised by the evolution of multidrug-resistant (MDR) pathogens. For life-threatening fungal infections, such as those caused by Candida albicans, overexpression of MDR1, which encodes an MDR efflux pump of the major facilitator superfamily (MFS), often confers resistance to chemically unrelated substances, including the most commonly used azole antifungals. As the development of new and efficacious antifungals has lagged far behind the ...

  3. Association of Mdr1 Gene C1236t Polymorphism with Idiopathic Males’ Infertility in Guilan Population

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    F Tajbakhsh

    2016-04-01

    Conclusion: The study findings revealed that a significant association was found between MDR1 polymorphism and idiopathic infertility (P= 0.001. Therefore, the results suggest that CT heterozygous genotype has a protective effect on male fertility (P= 0.01, OR= 0.41; 95%CI: 0.23- 0.84. However, to achieve more accurate results, it is necessary to examine a larger target population.

  4. Multidrug resistance mediated by a bacterial homolog of the human multidrug transporter MDR1.

    OpenAIRE

    van Veen, Hendrik W.; Venema, Koen; Bolhuis, Henk; Oussenko, Irina; Kok, Jan; Poolman, Bert; Driessen, Arnold J. M.; Konings, Wil N.

    1996-01-01

    Resistance of Lactococcus lactis to cytotoxic compounds shares features with the multidrug resistance phenotype of mammalian tumor cells. Here, we report the gene cloning and functional characterization in Escherichia coli of LmrA, a lactococcal structural and functional homolog of the human multidrug resistance P-glycoprotein MDR1. LmrA is a 590-aa polypeptide that has a putative topology of six alpha-helical transmembrane segments in the N-terminal hydrophobic domain, followed by a hydrophi...

  5. Polymorphisms in DNA Repair Genes and MDR1 and the Risk for Non-Hodgkin Lymphoma

    Directory of Open Access Journals (Sweden)

    Hee Nam Kim

    2014-04-01

    Full Text Available The damage caused by oxidative stress and exposure to cigarette smoke and alcohol necessitate DNA damage repair and transport by multidrug resistance-1 (MDR1. To explore the association between polymorphisms in these genes and non-Hodgkin lymphoma risk, we analyzed 15 polymorphisms of 12 genes in a population-based study in Korea (694 cases and 1700 controls. Four genotypes of DNA repair pathway genes (XRCC1 399 GA, OGG1 326 GG, BRCA1 871 TT, and WRN 787 TT were associated with a decreased risk for NHL [odds ratio (ORXRCC1 GA = 0.80, p = 0.02; OROGG1 GG = 0.70, p = 0.008; ORBRCA1 TT = 0.71, p = 0.048; ORWRN TT = 0.68, p = 0.01]. Conversely, the MGMT 115 CT genotype was associated with an increased risk for NHL (OR = 1.25, p = 0.04. In the MDR1 gene, the 1236 CC genotype was associated with a decreased risk for NHL (OR = 0.74, p = 0.04, and the 3435 CT and TT genotypes were associated with an increased risk (OR3435CT = 1.50, p < 0.0001; OR3435TT = 1.43, p = 0.02. These results suggest that polymorphisms in the DNA repair genes XRCC1, OGG1, BRCA1, WRN1, and MGMT and in the MDR1 gene may affect the risk for NHL in Korean patients.

  6. Reversing multidrug resistance in Caco-2 by silencing MDR1, MRP1, MRP2, and BCL-2/BCL-xL using liposomal antisense oligonucleotides.

    Directory of Open Access Journals (Sweden)

    Yu-Li Lo

    Full Text Available Multidrug resistance (MDR is a major impediment to chemotherapy. In the present study, we designed antisense oligonucleotides (ASOs against MDR1, MDR-associated protein (MRP1, MRP2, and/or BCL-2/BCL-xL to reverse MDR transporters and induce apoptosis, respectively. The cationic liposomes (100 nm composed of N-[1-(2,3-dioleyloxypropyl]-n,n,n-trimethylammonium chloride and dioleoyl phosphotidylethanolamine core surrounded by a polyethylene glycol (PEG shell were prepared to carry ASOs and/or epirubicin, an antineoplastic agent. We aimed to simultaneously suppress efflux pumps, provoke apoptosis, and enhance the chemosensitivity of human colon adenocarcinoma Caco-2 cells to epirubicin. We evaluated encapsulation efficiency, particle size, cytotoxicity, intracellular accumulation, mRNA levels, cell cycle distribution, and caspase activity of these formulations. We found that PEGylated liposomal ASOs significantly reduced Caco-2 cell viability and thus intensified epirubicin-mediated apoptosis. These formulations also decreased the MDR1 promoter activity levels and enhanced the intracellular retention of epirubicin in Caco-2 cells. Epirubicin and ASOs in PEGylated liposomes remarkably decreased mRNA expression levels of human MDR1, MRP1, MRP2, and BCL-2. The combined treatments all significantly increased the mRNA expressions of p53 and BAX, and activity levels of caspase-3, -8, and -9. The formulation of epirubicin and ASOs targeting both pump resistance of MDR1, MRP1, and MRP2 and nonpump resistance of BCL-2/BCL-xL demonstrated more superior effect to all the other formulations used in this study. Our results provide a novel insight into the mechanisms by which PEGylated liposomal ASOs against both resistance types act as activators to epirubicin-induced apoptosis through suppressing MDR1, MRP1, and MRP2, as well as triggering intrinsic mitochondrial and extrinsic death receptor pathways. The complicated regulation of MDR highlights the necessity

  7. Design of a hairpin polyamide, ZT65B, for targeting the inverted CCAAT box (ICB) site in the multidrug resistant (MDR1) gene.

    Science.gov (United States)

    Buchmueller, Karen L; Taherbhai, Zarmeen; Howard, Cameron M; Bailey, Suzanna L; Nguyen, Binh; O'Hare, Caroline; Hochhauser, Daniel; Hartley, John A; Wilson, W David; Lee, Moses

    2005-12-01

    A novel hairpin polyamide, ZT65B, containing a 3-methylpicolinate moiety was designed to target the inverted CCAAT box (ICB) of the human multidrug resistance 1 gene (MDR1) promoter. Binding of nuclear factor-Y (NF-Y) to the ICB site upregulates MDR1 gene expression and is, therefore, a good target for anticancer therapeutic agents. However, it is important to distinguish amongst different promoter ICB sites so that only specific genes will be affected. All ICB sites have the same sequence but they differ in the sequence of the flanking base pairs, which can be exploited in the design of sequence-specific polyamides. To test this hypothesis, ten ICB-containing DNA hairpins were designed with different flanking base pairs; the sequences ICBa and ICBb were similar to the 3'-ICB site of MDR1 (TGGCT). Thermal-denaturation studies showed that ZT65B effectively targeted ICBa and ICBb (DeltaTM=6.5 and 7.0 degrees C) in preference to the other DNA hairpins (ICBc (5.0 degrees C). DNase I-footprinting assays were carried out with the topoisomerase IIalpha-promoter sequence, which contains five ICB sites; of these, ICB1 and ICB5 are similar to the ICB site of MDR1. ZT65B was found to selectively bind ICB1 and ICB5; footprints were not observed with ICB2, ICB3, or ICB4. A strong, positive induced ligand band at 325 nm in CD studies confirmed that ZT65B binds in the DNA minor groove. The selectivity of ZT65B binding to hairpins that contained the MDR1 ICB site compared to one that did not (ICBd) was confirmed by surface-plasmon studies, and equilibrium constants of 5x10(6)-1x10(7) and 4.6x10(5) M-1 were obtained with ICB1, ICB5,and ICB2 respectively. ZT65B and the previously published JH37 (J. A. Henry, et al. Biochemistry 2004, 43, 12 249-12 257) serve as prototypes for the design of novel polyamides. These can be used to specifically target the subset of ubiquitous gene elements known as ICBs, and thereby affect the expression of one or a few proteins.

  8. Differential Requirement of the Transcription Factor Mcm1 for Activation of the Candida albicans Multidrug Efflux Pump MDR1 by Its Regulators Mrr1 and Cap1▿

    OpenAIRE

    Mogavero, Selene; Tavanti, Arianna; Senesi, Sonia; Rogers, P. David; Morschhäuser, Joachim

    2011-01-01

    Overexpression of the multidrug efflux pump Mdr1 causes increased fluconazole resistance in the pathogenic yeast Candida albicans. The transcription factors Mrr1 and Cap1 mediate MDR1 upregulation in response to inducing stimuli, and gain-of-function mutations in Mrr1 or Cap1, which render the transcription factors hyperactive, result in constitutive MDR1 overexpression. The essential MADS box transcription factor Mcm1 also binds to the MDR1 promoter, but its role in inducible or constitutive...

  9. Construction and identification of recombinant adenovirus vector containing MDR1-CD∷upp gene driven by human MDR1 promoter%MDR1启动子调控CD∷尿嘧啶磷酸核糖转移酶重组腺病毒载体的构建及表达

    Institute of Scientific and Technical Information of China (English)

    卢实; 黄畦; 蔡春芳; 陈大瑜; 王泽华

    2005-01-01

    目的构建由人MDR1启动子调控CD∷upp融合基因表达的重组腺病毒,为对耐药肿瘤体内外靶向基因治疗奠定基础.方法自行设计一对含XhoⅠ和HindⅢ酶切位点的MDR1引物,从外周血中提取人类基因组DNA,通过PCR扩增MDR1启动子并插入PGL3-enhancer载体上,获得PGL3-MDR1质粒.从PORF-CD∷upp质粒中切下CD∷upp基因,插入PGL3-MDR1MDR1启动子下游,并从中切下目的基因MDR1-CD∷upp,克隆到腺病毒穿梭质粒中,将带目的基因的穿梭质粒pAdTrack-MDR1-CD∷upp.与含有pAdeasy-1的BJ5183菌电转化,筛选提取>30 kb的阳性克隆,经线性化后转染293细胞,通过观察绿色荧光蛋白(GFP)的表达及PCR扩增出重组腺病毒中的目的基因MDR1、CD∷upp等方法加以鉴定.结果成功构建了含MDR1-CD∷upp靶向自杀基因的重组腺病毒载体Ad-MDR1-CD∷upp,病毒滴度为3.0×1010 pfu/ml.结论该重组腺病毒的构建为下一步研究其对MDR1耐药细胞系的特异性杀伤作用和对耐药肿瘤模型的靶向基因治疗提供基础.

  10. RNA干扰MDR1基因对乳腺癌多细胞球阿霉素敏感性的影响%Effect of MDR1 Gene Silencing on Adriamycin Sensitivity of Breast Carcinoma Multicellular Spheroids by RNA Interference

    Institute of Scientific and Technical Information of China (English)

    郑庆玲; 顾栋桦; 平金良; 朱荣; 陈琦

    2011-01-01

    目的 通过RNA干扰沉默MDR1基因,探讨后者在乳腺癌多细胞球阿霉素耐药中的作用.方法 用liquid overlay技术培养获得多细胞球(multicellular spheroids, MCS),用脂质体转染法把特异针对MDR1基因的双链小RNA干扰片段导入MCF-7细胞中,采用台盼蓝拒染法检测阿霉素对MCF-7的细胞抑制率,MDR1 mRNA水平及蛋白水平分别用RT-PCR和免疫印迹法检测,用荧光光度计法检测阿霉素在细胞内的蓄积情况.结果 多细胞球形成后,阿霉素对MCF-7细胞的抑制率明显减少,MDR1 mRNA及蛋白水平明显升高,阿霉素在细胞内的蓄积量减少;RNA干扰法能明显抑制MDR1基因表达,增加阿霉素在MCS细胞中的蓄积,提高阿霉素对MCS的细胞抑制率.结论 多细胞球的形成可以增强MCF-7细胞的阿霉素耐药性,RNA干扰沉默MDR1基因可以部分逆转MCF-7多细胞球的阿霉素耐药.%Objective To investigate the role of MDRI gene expression in drug resistance of multicellular spheroids of breast carcinoma to Adriamycin( ADM) by RNA interfering technique. Methods MCF - 7 multicellular spheroids were obtained from liquid overlay technique culture. MDR1 - targeted small interfering double - stranded RNAs ( SiRNA) were introduced into MCF - 7 cells by lipofectamine. Adriamycin resistance was detected with trypan blue exclusion testing. MDR1 mRNA and MRD1 protein levels were determined by reverse transcroption - polymerase chain reaction( RT - PCR) and Westernblot, and Adriamycin accumulation in MCF - 7 cells was tested by fluorescence spectrophotometry. Results Compared with monolayer cells, MCS showed lower cell inhibitory rate and ADM accumulation in cells after ADM expoaure for 24h, and both mRNA and protein level of MDRI were elevated in MCS obviously. RNA inter ference markedly inhibited the expressiong of MDRI mRNA and protein, and enhanced the intracellular accumulation of andpartially restored sensitivity to ADM in MCF -7 MCS. Conclusion Breast

  11. 血清标志物(NSE、CEA、CA-125、CYFRA21-1)和分子标志物(MDR-1、LRP、RRM-1、EGFR、ERCC-1、BRCA-1)在非小细胞肺癌患者原发灶和转移淋巴结的表达%Expression of serum markers (NSE,CEA, CA-125,CYFRA 21-1)and molecular mark-ers (MDR-1,LRP,RRM-1,EGFR,ERCC-1,BRCA-1)in primary sites and metastatic lymph nodes of lung cancer patients

    Institute of Scientific and Technical Information of China (English)

    郭楠楠; 李珊珊; 张文; 于长海; 俞建琦; 李少军

    2014-01-01

    AIM:To investigate the different expressions of ser-um markers and molecular markers in the primary tumor and the metastatic lymph nodes of lung cancer patients with four histologi-cal subtypes.METHODS:There were 48 cases of lung cancer patients who underwent thoracic surgery for removal of primary and metastatic lesions had been enrolled for testing.RESULTS:Expression of ERCC-1 was significantly different in primary tumors and metastatic sites (P=0.007 )and the serum level of CEA was significantly different for patients with different cancer subtypes (P =0.008 ). CONCLUSION:Tumor molecular markers have value to estimate prognosis and select treatments for patients.%目的:研究不同血清标志物及分子标志物在肺癌不同病理亚型、原发灶与转移淋巴结间表达的差异.方法:对48例住院接受开胸手术切除原发病灶及转移淋巴结的患者进行4种血清标志物和6种分子标记物检测.结果:ERCC-1的表达在原发肿瘤和转移部位间有显著差异(P=0.007);CEA的血清水平在不同肿瘤亚型患者间存在显著差异(P=0.008).结论:标志物检测对于患者预后的判断及治疗方案具有一定价值.

  12. The value of the MDR1 reversal agent PSC-833 in addition to daunorubicin and cytarabine in the treatment of elderly patients with previously untreated acute myeloid leukemia (AML), in relation to MDR1 status at diagnosis.

    Science.gov (United States)

    van der Holt, Bronno; Löwenberg, Bob; Burnett, Alan K; Knauf, Wolfgang U; Shepherd, John; Piccaluga, Pier Paolo; Ossenkoppele, Gert J; Verhoef, Gregor E G; Ferrant, Augustin; Crump, Michael; Selleslag, Dominik; Theobald, Matthias; Fey, Martin F; Vellenga, Edo; Dugan, Margaret; Sonneveld, Pieter

    2005-10-15

    To determine whether MDR1 reversal by the addition of the P-glycoprotein (P-gp) inhibitor PSC-833 to standard induction chemotherapy would improve event-free survival (EFS), 419 untreated patients with acute myeloid leukemia (AML) aged 60 years and older were randomized to receive 2 induction cycles of daunorubicin and cytarabine with or without PSC-833. Patients in complete remission were then given 1 consolidation cycle without PSC-833. Neither complete response (CR) rate (54% versus 48%; P = .22), 5-year EFS (7% versus 8%; P = .53), disease-free survival (DFS; 13% versus 17%; P = .06) nor overall survival (OS; 10% in both arms; P = .52) were significantly improved in the PSC-833 arm. An integrated P-gp score (IPS) was determined based on P-gp function and P-gp expression in AML cells obtained prior to treatment. A higher IPS was associated with a significantly lower CR rate and worse EFS and OS. There was no significant interaction between IPS and treatment arm with respect to CR rate and survival, indicating also a lack of benefit of PSC-833 in P-gp-positive patients. The role of strategies aimed at inhibitory P-gp and other drug-resistance mechanisms continues to be defined in the treatment of patients with AML.

  13. Hinokitiol-Loaded Mesoporous Calcium Silicate Nanoparticles Induce Apoptotic Cell Death through Regulation of the Function of MDR1 in Lung Adenocarcinoma Cells

    Directory of Open Access Journals (Sweden)

    Yu-Fang Shen

    2016-04-01

    Full Text Available Hinokitiol is a tropolone-related compound found in heartwood cupressaceous plants. Hinokitiol slows the growth of a variety of cancers through inhibition of cell proliferation. The low water solubility of hinokitiol leads to less bioavailability. This has been highlighted as a major limiting factor. In this study, mesoporous calcium silicate (MCS nanoparticles, both pure and hinokitiol-loaded, were synthesized and their effects on A549 cells were analyzed. The results indicate that Hino-MCS nanoparticles induce apoptosis in higher concentration loads (>12.5 μg/mL for A549 cells. Hino-MCS nanoparticles suppress gene and protein expression levels of multiple drug resistance protein 1 (MDR1. In addition, both the activity and the expression levels of caspase-3/-9 were measured in Hino-MCS nanoparticle-treated A549 cells. The Hino-MCS nanoparticles-triggered apoptosis was blocked by inhibitors of pan-caspase, caspase-3/-9, and antioxidant agents (N-acetylcysteine; NAC. The Hino-MCS nanoparticles enhance reactive oxygen species production and the protein expression levels of caspase-3/-9. Our data suggest that Hino-MCS nanoparticles trigger an intrinsic apoptotic pathway through regulating the function of MDR1 and the production of reactive oxygen species in A549 cells. Therefore, we believe that Hino-MCS nanoparticles may be efficacious in the treatment of drug-resistant human lung cancer in the future.

  14. Lack of Association of OPRM1 and ABCB1 Single-Nucleotide Polymorphisms to Oxycodone Response in Postoperative Pain

    DEFF Research Database (Denmark)

    Zwisler, Stine T; Enggaard, Thomas P; Mikkelsen, Soeren;

    2011-01-01

    Purpose: The aim of the study was to search for an association between the single-nucleotide polymorphisms A118G in OPRM1 and C3435T and G2677T/A in ABCB1 and the analgesic effect of intravenous oxycodone in postoperative pain. Methods: There were 268 patients with postoperative pain after......, primarily, thyroidectomy. At given times during the first 24 hours postoperatively, their pain was rated at rest and during activity according to a numeric rating scale (0 = no pain, 10 = worst possible pain) and calculated as pain time area under the curve(0-24 hours). A negative answer in a final...... questionnaire and/or the use of rescue medication categorized a patient as a non-responder. Results: For OPRM1, there was no difference found between the wild type and the variant allele in the percentages of nonresponders (118AA = 16.4% vs 118AG/118GG = 17.0%, P = 1.0) or in the pain ratings. For ABCB1...

  15. ABCB1 and ABCC2 and the risk of distant metastasis in Thai breast cancer patients treated with tamoxifen

    Directory of Open Access Journals (Sweden)

    Sensorn I

    2016-04-01

    Full Text Available Insee Sensorn,1,* Chonlaphat Sukasem,2,* Ekaphop Sirachainan,3 Montri Chamnanphon,2 Ekawat Pasomsub,4 Narumol Trachu,5 Porntip Supavilai,1 Darawan Pinthong,1 Sansanee Wongwaisayawan6 1Department of Pharmacology, Faculty of Science, Mahidol University, 2Division of Pharmacogenomics and Personalized Medicine, Department of Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, 3Division of Medical Oncology, Department of Medicine, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, 4Division of Virology, Department of Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, 5Research Center, Faculty of Medicine, Ramathibodi Hospital, 6Division of Anatomical Pathology, Department of Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand *These authors contributed equally to this work Background: Genetic polymorphisms of drug-metabolizing enzymes and transporters have been extensively studied with regard to tamoxifen treatment outcomes. However, the results are inconclusive. Analysis of organ-specific metastasis may reveal the association of these pharmacogenetic factors. The aim of this study is to investigate the impact of CYP3A5, CYP2D6, ABCB1, and ABCC2 polymorphisms on the risk of all distant and organ-specific metastases in Thai patients who received tamoxifen adjuvant therapy. Methods: Genomic DNA was extracted from blood samples of 73 patients with breast cancer who received tamoxifen adjuvant therapy. CYP3A5 (6986A>G, CYP2D6 (100C>T, ABCB1 (3435C>T, and ABCC2 (-24C>T were genotyped using allelic discrimination real-time polymerase chain reaction assays. The impacts of prognostic clinical factors and genetic variants on disease-free survival were analyzed using the Kaplan–Meier method and Cox regression analysis. Results: In the univariate analysis, primary tumor size >5 cm was significantly associated with increased risk of distant metastasis (P=0

  16. 沉默MDR1基因增强急性早幼粒白血病耐药细胞HT9药物敏感性%Effect of RNAi Silencing MDR1 Gene on the Sensitivity of Multidrug Resistant Actue Promyelocytic Leukemia Cells HT9 to Drugs

    Institute of Scientific and Technical Information of China (English)

    邵淑丽; 李旭艳; 张伟伟; 恽东泽; 付博; 张珍珠

    2012-01-01

    该研究利用短发卡RNA(small hairpin RNA,shRNA)表达载体沉默HT9急性早幼粒白血病耐药细胞MDR1基因表达,以提高细胞对三尖杉酯碱、阿霉素的敏感性.通过设计合成编码shRNA的DNA模板序列,定向克隆到pSilencer 2.1-U6 neo质粒,成功构建1个P-gp蛋白基因特异的shRNA表达载体,稳定电转染HT9细胞,实时荧光定量PCR分析MDR1 mRNA表达,Western blot检测细胞P-gp蛋白表达,流式细胞术检测P-gp蛋白外排泵功能,MTT法检测细胞对药物敏感性.结果显示,成功构建了shRNA表达载体pSilencer2.1-U6 neo-MDR1,转染HT9细胞后,PCR检测重组质粒整合到HT9/sh-2.1-1细胞基因组DNA,获得稳定遗传;HT9/sh-2.1-1细胞MDR1mRNA达降低了78.84%(P<0.01),P-gp蛋白表达降低了48.27%(P<0.05),细胞内Rho123相对荧光强度由(10.8±0.58)%升高至(73.56士1.37)%;转染细胞对三尖杉酯碱、阿霉素敏感性明显增强,IC50分别由(2.06±0.15) μmol/L降至(0.57±0.01) μmol/L、(4.04士017) μmol/L降至(1.56±0.05) μmol/L.提示shRNA干扰表达载体pSilencer2.1-U6 neo-MDR1能够稳定、持久地抑制MDR1基因表达,并能有效增强HT9细胞对三尖杉酯碱、阿霉素的敏感性.%The study investigated the effects of RNAi silencing MDR1 gene, increase the sensitivity of multidrug resistant actue promyelocytic leukemia cells HT9 to harringtonine and doxorubicin. One short hairpin RNA (small hairpin RNA, shRNA) was designed and constructed into pSilencer2.1-U6 neo plasmid. MDR1 shRNA expression plasmid pSilencer 2.1-U6 neo-MDRl was constructed and introduced into HT9 cells. MDR1 mRNA was assayed by real-time fluorescent quantitative PCR. The P-gp protein was assayed by Western blot. The pump function of P-gp was assayed by FCM. The sensitivity of cells to drugs were assayed by MTT. The results suggested that pSilencer 2.1-U6 neo-MDRl expression plasmid was constructed successfully. The results of PCR showed that the shRNA recombinant plasmid

  17. Clopidogrel Resistance and ABCB1 (3435C > T) Gene Polymorphism: A Meta Analysis%氯吡格雷抵抗与ABCB1 3435C>T基因位点多态性的Meta分析

    Institute of Scientific and Technical Information of China (English)

    彭锐; 张洪; 张英; 魏丹芸

    2015-01-01

    目的 探讨氯吡格雷抵抗与ABCB1 3435C >T基因住点多态性关联性.方法 计算机检索Pubmed、Science direct、Wiley online library、Web of Science、中国知网、万方数据库和维普中文科技期刊数据库,纳入氯吡格雷抵抗与氯吡格雷有效的随机对照试验,同时查阅检索结果中所附相似文献及参考文献,检索文献均为建库至2014年6月25日,采用RevMan5.0软件进行Meta分析及其他统计学分析.结果 共纳入文献6篇;患者中氯吡格雷抵抗2 619例、氯吡格雷有效2 799例.Meta分析结果显示,3435C>T位点多态性在等位基因模型、显性基因模型、共显性基因模型(CC/CT)和超显性基因模型下整体效应有统计学意义(P<0.05):等位基因模型OR=1.27,95% CI(1.13,1.42),显性基因模型OR=1.42,95% CI(1.22,1.65),共显性基因模型(CC/CT) OR=1.43,95% CI(1.20,1.69),超显性基因模型OR=1.30,95%CI(1.11,1.52).人种亚组分析表明,欧洲地区ABCB1 3435C>T位点基因多态性与氯吡格雷抵抗均无统计学意义(P>0.05);而亚洲地区ABCB1 3435C>T位点基因多态性与氯吡格雷抵抗在等位基因模型、显性基因模型、共显性基因模型(CC/CT)和超显性基因模型下整体效应有统计学意义(P<0.05):等位基因模型OR=1.57,95%CI(1.34,1.84),显性基因模型OR =2.11,95%CI(1.71,2.60)、共显性基因模型(CC/CT) OR=2.15,95% CI(1.72,2.69),超显性基因模型OR=1.82,95% CI(1.48,2.24).结论 亚洲地区,ABCB1 3435C>T位点基因多态性与氯吡格雷抵抗有相关性,而在欧洲地区则无相关性.

  18. Functional analysis of chimeric genes obtained by exchanging homologous domains of the mouse mdr1 and mdr2 genes.

    OpenAIRE

    Buschman, E; Gros, P.

    1991-01-01

    A full-length cDNA clone for the mouse mdr1 gene can confer multidrug resistance when introduced by transfection into otherwise drug-sensitive cells. In the same assay, a full-length cDNA clone for a closely related member of the mouse mdr gene family, mdr2, fails to confer multidrug resistance. To identify the domains of mdr1 which are essential for multidrug resistance and which may be functionally distinct in mdr2, we have constructed chimeric cDNA molecules in which discrete domains of md...

  19. Mutace genu v MDR1 u psů ve vztahu k citlivosti na léčiva

    OpenAIRE

    Patermannová, Veronika

    2014-01-01

    This work deals with the multidrug resistance gene (MDR1), its structure, function, localization on dog's genome and especially its dysfunction in case of mutation. Work gives information about heredity of mutated alleles MDR1 gene, detection mutation using polymerase chain reaction (PCR). Information are written as a literature review and were drawn from scholarly articles. On base these articles was created summary of frequency all genotypes MDR1 gene in dogs in Czech Republic and foreign c...

  20. The value of the MDR1 reversal agent PSC-833 in addition to daunorubicin and cytarabine in the treatment of elderly patients with previously untreated acute myeloid leukemia (AML), in relation to MDR1 status at diagnosis

    NARCIS (Netherlands)

    van der Holt, B; Lowenberg, B; Burnett, AK; Knauf, WU; Shepherd, J; Piccaluga, PP; Ossenkoppele, GJ; Verhoef, GEG; Ferrant, A; Crump, M; Selleslag, D; Theobald, M; Fey, MF; Vellenga, E; Dugan, M; Sonneveld, P

    2005-01-01

    To determine whether MDR1 reversal by the addition of the P-glycoprotein (P-gp) inhibitor PSC-833 to standard induction chemotherapy would improve event-free survival (EFS), 419 untreated patients with acute myeloid leukemia (AML) aged 60 years and older were randomized to receive 2 induction cycles

  1. Association of CYP3A4/5, ABCB1 and ABCC2 polymorphisms and clinical outcomes of Thai breast cancer patients treated with tamoxifen

    Directory of Open Access Journals (Sweden)

    Sensorn I

    2013-08-01

    Full Text Available Insee Sensorn,1 Ekaphop Sirachainan,2 Montri Chamnanphon,3 Ekawat Pasomsub,4 Narumol Trachu,5 Porntip Supavilai,1 Chonlaphat Sukasem,3 Darawan Pinthong11Department of Pharmacology, Faculty of Science, Mahidol University, Bangkok, Thailand; 2Division of Medical Oncology, Department of Medicine, 3Division for Pharmacogenomics and Personalized Medicine, 4Division for Virology, Department of Pathology, 5Research Center, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, ThailandBackground: Pharmacogenetic study of cytochrome P450 (CYP gene CYP2D6 and tamoxifen outcomes remain controversial. Apart from CYP2D6, other drug-metabolizing enzymes and transporters also play a role in tamoxifen metabolic pathways. The aim of this study is to investigate the impact of CYP3A4/5, ABCB1, and ABCC2 polymorphisms on the risk of recurrence in Thai patients who received tamoxifen adjuvant therapy.Methods: Patients with early-stage breast cancer who received tamoxifen adjuvant therapy were recruited in this study. All six single-nucleotide polymorphisms (SNPs, including CYP3A4*1B (-392 A>G/*18(878 T>C, CYP3A5*3(6986 G>A, ABCB1 3435 C>T, ABCC2*1C (-24 C>T, and ABCC2 68231 A>G, were genotyped using real-time polymerase chain reaction assays. The impacts of genetic variants on disease-free survival (DFS were analyzed using the Kaplan–Meier method and Cox regression analysis.Results: The ABCB1 3435 C>T was found to have the highest allele frequency among other variants; however, CYP3A4*1B/*18 could not be found in this study. Patients with heterozygous ABCB1 3435 CT genotype showed significantly shorter DFS than those with homozygous 3435 CC genotype (P = 0.041. In contrast, patients who carried homozygous 3435 TT genotype showed no difference in DFS from wild-type 3435 CC patients. Cox regression analysis showed that the relative risk of recurrence was increased by five times (P = 0.043; hazard ratio = 5.11; 95% confidence interval: 1.05–24

  2. Associations of ABCB1, NFKB1, CYP3A, and NR1I2 polymorphisms with cyclosporine trough concentrations in Chinese renal transplant recipients

    Institute of Scientific and Technical Information of China (English)

    Yu ZHANG; Jia-li LI; Qian FU; Xue-ding WANG; Long-shan LIU; Chang-xi WANG; Wen XIE

    2013-01-01

    Aim:Cyclosporine requires close therapeutic drug monitoring because of its narrow therapeutic index and marked inter-individual pharmacokinetic variation.In this study,we investigated the associations of CYP3A4,CYP3A5,ABCB1,NFKB1,and NR1I2 polymorphisms with cyclosporine concentrations in Chinese renal transplant recipients in the early period after renal transplantation.Methods:A total of 101 renal transplant recipients receiving cyclosporine were genotyped for CYP3A4*1G,CYP3A5*3,ABCB1 C1236T,G2677T/A,C3435T,NFKB1-94 ins/del ATTG,and NR1I2 polymorphisms.Cyclosporine whole blood levels were measured by a fluorescence polarization immunoassay.Trough concentrations of cyclosporine were determined for days 7-18 following transplantation.Results:The dose-adjusted trough concentration (C0) of cyclosporine in ABCB1 2677 TT carriers was significantly higher than that in GG carriers together with GT carriers [90.4±24.5 vs 67.8±26.8 (ng/mL)/(mg/kg),P=0.001].ABCB1 3435 TT carriers had a significantly higher dose-adjusted C0 of cyclosporine than CC carriers together with CT carriers [92.0±24.0 vs 68.4±26.5 (ng/mL)/(mg/kg),P=0.002].Carriers of the ABCB1 1236TT-2677TT-3435TT haplotype had a considerably higher CsA C0/D than carriers of other genotypes [97.2±21.8 vs 68.7±26.9 (ng/mL)/(mg/kg),P=0.001].Among non-carriers of the ABCB1 2677 TT and 3435 TT genotypes,patients with the NFKB1-94 ATTG ins/ins genotype had a significantly higher dose-adjusted C0 than those with the-94 ATTG del/del genotype [75.9±32.9 vs 55.1±15.1 (ng/mL)/(mg/kg),P=0.026].Conclusion:These results illustrate that the ABCB1 and NFKB1 genotypes are closely correlated with cyclosporine trough concentrations,suggesting that these SNPs are useful for determining the appropriate dose of cyclosporine.

  3. Zosuquidar restores drug sensitivity in P-glycoprotein expressing acute myeloid leukemia (AML)

    International Nuclear Information System (INIS)

    Chemotherapeutic drug efflux via the P-glycoprotein (P-gp) transporter encoded by the MDR1/ABCB1 gene is a significant cause of drug resistance in numerous malignancies, including acute leukemias, especially in older patients with acute myeloid leukemia (AML). Therefore, the P-gp modulators that block P-gp-mediated drug efflux have been developed, and used in combination with standard chemotherapy. In this paper, the capacity of zosuquidar, a specific P-gp modulator, to reverse chemoresistance was examined in both leukemia cell lines and primary AML blasts. The transporter protein expressions were analyzed by flow cytometry using their specific antibodies. The protein functionalities were assessed by the uptake of their fluorescence substrates in presence or absence their specific modulators. The drug cytotoxicity was evaluated by MTT test. Zosuquidar completely or partially restored drug sensitivity in all P-gp-expressing leukemia cell lines tested and enhanced the cytotoxicity of anthracyclines (daunorubicin, idarubicin, mitoxantrone) and gemtuzumab ozogamicin (Mylotarg) in primary AML blasts with active P-gp. In addition, P-gp inhibition by zosuquidar was found to be more potent than cyclosporine A in cells with highly active P-gp. These in vitro studies suggest that zosuquidar may be an effective adjunct to cytotoxic chemotherapy for AML patients whose blasts express P-gp, especially for older patients

  4. Influence of functional polymorphisms of the MDR1 gene on vincristine pharmacokinetics in childhood acute lymphoblastic leukemia.

    NARCIS (Netherlands)

    Plasschaert, S.L.A.; Groninger, E.; Boezen, M.; Kema, I.P.; Vries, E.G.F. de; Uges, D.R.A.; Veerman, A.J.P.; Kamps, W.A.; Vellenga, E.; Graaf, S.S.N. de; Bont, E.S. de

    2004-01-01

    OBJECTIVE: Our objective was to investigate the effect of single nucleotide polymorphisms (SNPs) in the P-glycoprotein MDR1 gene on vincristine pharmacokinetics and side effects in childhood acute lymphoblastic leukemia. METHODS: From 52 of 70 children who participated in a previous study on vincris

  5. Contribution of mdr1b-type P-glycoprotein to okadaic acid resistance in rat pituitary GH3 cells.

    Science.gov (United States)

    Ritz, V; Marwitz, J; Sieder, S; Ziemann, C; Hirsch-Ernst, K I; Quentin, I; Steinfelder, H J

    1999-08-01

    Okadaic acid as well as other, structurally different, inhibitors of serine/threonine phosphatases 1 and 2A induce apoptosis in pituitary GH3 cells. Incubation with stepwise raised concentrations of okadaic acid resulted in the isolation of cells that were increasingly less sensitive to the cytotoxic effect of this agent. After about 18 months cells were selected that survived at 300 nM okadaic acid, which is about 30 times the initially lethal concentration. This study revealed that a major pharmacokinetic mechanism underlying cell survival was the development of a P-glycoprotein-mediated multidrug resistance (MDR) phenotype. The increase in mRNA levels of the mdr1b P-glycoprotein isoform correlated with the extent of drug resistance. Functional assays revealed that increasing drug resistance was paralleled by a decreased accumulation of rhodamine 123, a fluorescent dye which is a substrate of mdr1-mediated efflux activity. Resistance could be abolished by structurally different chemosensitizers of P-glycoprotein function like verapamil and reserpine but not by the leukotriene receptor antagonist MK571 which is a modulator of the multidrug resistance-associated protein (MRP). Okadaic acid resistance included cross-resistance to other cytotoxic agents that are substrates of mdr1-type P-glycoproteins, like doxorubicin and actinomycin D, but not to non-substrates of mdr1, e.g. cytosine arabinoside. Thus, functional as well as biochemical features support the conclusion that okadaic acid is a substrate of the mdr1-mediated efflux activity in rat pituitary GH3 cells. Maintenance of resistance after withdrawal of okadaic acid as well as metaphase spreads of 100 nM okadaic acid-resistant cells suggested a stable MDR genotype without indications for the occurrence of extrachromosomal amplifications, e.g. double minute chromosomes.

  6. SNP genetic polymorphisms of MDR-1, CYP1A2 and CYPB11 genes in four canine breeds upon toxicological evaluation.

    Science.gov (United States)

    Gagliardi, Rosa; Llambí, Silvia; Arruga, M Victoria

    2015-01-01

    The fields of pharmacogenetics and pharmacogenomics have become increasingly promising regarding the clinical application of genetic data to aid in prevention of adverse reactions. Specific screening tests can predict which animals express modified proteins or genetic sequences responsible for adverse effects associated with a drug. Among the genetic variations that have been investigated in dogs, the multidrug resistance gene (MDR) is the best studied. However, other genes such as CYP1A2 and CYP2B11 control the protein syntheses involved in the metabolism of many drugs. In the present study, the MDR-1, CYP1A2 and CYP2B11 genes were examined to identify SNP polymorphisms associated with these genes in the following four canine breeds: Uruguayan Cimarron, Border Collie, Labrador Retriever and German Shepherd. The results revealed that several SNPs of the CYP1A2 and CYP2B11 genes are potential targets for drug sensitivity investigations. PMID:25797294

  7. Laurus nobilis L. Seed Extract Reveals Collateral Sensitivity in Multidrug-Resistant P-Glycoprotein-Expressing Tumor Cells.

    Science.gov (United States)

    Saab, Antoine M; Guerrini, Alessandra; Zeino, Maen; Wiench, Benjamin; Rossi, Damiano; Gambari, Roberto; Sacchetti, Gianni; Greten, Henry Johannes; Efferth, Thomas

    2015-01-01

    The frequent failure of standard cancer chemotherapy requires the development of novel drugs capable of killing otherwise drug-resistant tumors. Here, we have investigated a chloroform extract of Laurus nobilis seeds. Fatty acids and 23 constituents of the volatile fraction were identified by gas chromotography/flame ionization detection (GC/FID) and gas chromatography/mass spectrometry (GC/MS), in good agreement with (1)H NMR (nuclear magnetic resonance) spectrum. Multidrug-resistant P-glycoprotein-expressing CEM/ADR5000 leukemia cells were hypersensitive (collaterally sensitive) toward this extract compared to drug-sensitive CCRF-CEM cells, whereas CEM/ADR5000 cells were 2586-fold resistant to doxorubicin as control drug. Collateral sensitivity was verified by measurement of apoptotic cells by flow cytometry. The log10IC50 values of 3 compounds in the extract (limonene, eucalyptol, oleic acid) did not correlate with mRNA expression of the P-glycoprotein-coding ABCB1/MDR1 gene and accumulation of the P-glycoprotein substrate rhodamine in the NCI panel of tumor cell lines. A microarray-based profile of 20 genes predicted resistance to doxorubicin and 7 other anticancer drugs involved in the multidrug resistance phenotype but not to limonene, eucalyptol and oleic acid. In conclusion, our results show that Laurus nobilis seed extract is suitable to kill multidrug-resistant P-glycoprotein expressing tumor cells.

  8. Genetic association analysis of ATP binding cassette protein family reveals a novel association of ABCB1 genetic variants with epilepsy risk, but not with drug-resistance.

    Directory of Open Access Journals (Sweden)

    Shabeesh Balan

    Full Text Available Epilepsy constitutes a heterogeneous group of disorders that is characterized by recurrent unprovoked seizures due to widely different etiologies. Multidrug resistance remains a major issue in clinical epileptology, where one third of patients with epilepsy continue to have seizures. Role of efflux transporters in multidrug resistant epilepsy has been attributed to drug-resistant epilepsy although, with discrepant observation in genetic studies. These discrepancies could be attributed to variety of factors such as variable definition of the anti-epileptic drug (AED-resistance, variable epilepsy phenotypes and ethnicities among the studies. In the present study we inquired the role of multidrug transporters ABCB1 and ABCG2 variants in determining AED-resistance and susceptibility to epilepsy in three well-characterized cohorts comprising of mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS (prototype for AED-resistant epilepsy; juvenile myoclonic epilepsy (JME (prototype for AED-responsive epilepsy; and healthy non-epileptic controls, in 738 subjects of Malayalam speaking south Indian ancestry. ABCB1 and ABCG2 variants were not found to be associated with drug resistance when AED-resistant and AED-responsive cohorts were compared. However, a significant association was observed between ABCB1 (C3435T rs1045642 and risk of having epilepsy (MTLE-HS and JME pooled cohort; genotypic p-value = 0.0002; allelic p-value = 0.004. This association was seen persistent with MTLE-HS (genotypic p-value = 0.0008; allelic p-value = 0.004 and also with JME (genotypic p-value = 0.01; allelic p-value = 0.05 cohort individually. In-silico functional prediction indicated that ABCB1 rs1045642 has a deleterious impact on protein coding function and in splicing regulation. We conclude that the ABCB1 and ABCG2 variants do not confer to AED-resistance in the study population. However, ABCB1 rs1045642 increases vulnerability to epilepsy with greater tendency

  9. Genetic association analysis of ATP binding cassette protein family reveals a novel association of ABCB1 genetic variants with epilepsy risk, but not with drug-resistance.

    Science.gov (United States)

    Balan, Shabeesh; Bharathan, Sumitha Prameela; Vellichiramal, Neetha Nanoth; Sathyan, Sanish; Joseph, Vijai; Radhakrishnan, Kurupath; Banerjee, Moinak

    2014-01-01

    Epilepsy constitutes a heterogeneous group of disorders that is characterized by recurrent unprovoked seizures due to widely different etiologies. Multidrug resistance remains a major issue in clinical epileptology, where one third of patients with epilepsy continue to have seizures. Role of efflux transporters in multidrug resistant epilepsy has been attributed to drug-resistant epilepsy although, with discrepant observation in genetic studies. These discrepancies could be attributed to variety of factors such as variable definition of the anti-epileptic drug (AED)-resistance, variable epilepsy phenotypes and ethnicities among the studies. In the present study we inquired the role of multidrug transporters ABCB1 and ABCG2 variants in determining AED-resistance and susceptibility to epilepsy in three well-characterized cohorts comprising of mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) (prototype for AED-resistant epilepsy); juvenile myoclonic epilepsy (JME) (prototype for AED-responsive epilepsy); and healthy non-epileptic controls, in 738 subjects of Malayalam speaking south Indian ancestry. ABCB1 and ABCG2 variants were not found to be associated with drug resistance when AED-resistant and AED-responsive cohorts were compared. However, a significant association was observed between ABCB1 (C3435T) rs1045642 and risk of having epilepsy (MTLE-HS and JME pooled cohort; genotypic p-value = 0.0002; allelic p-value = 0.004). This association was seen persistent with MTLE-HS (genotypic p-value = 0.0008; allelic p-value = 0.004) and also with JME (genotypic p-value = 0.01; allelic p-value = 0.05) cohort individually. In-silico functional prediction indicated that ABCB1 rs1045642 has a deleterious impact on protein coding function and in splicing regulation. We conclude that the ABCB1 and ABCG2 variants do not confer to AED-resistance in the study population. However, ABCB1 rs1045642 increases vulnerability to epilepsy with greater tendency for MTLE

  10. 药物基因组学相关P450和ABCB1多态性及SNP检测技术%Pharmacogenomics-related P450 and ABCB1 Polymorphisms and SNP Detection Technology

    Institute of Scientific and Technical Information of China (English)

    眭维国; 张若菡; 陈洁晶; 戴勇

    2011-01-01

    药物基因组学(phamacogenomics)是临床检测遗传差异引起药物应答个体性差异的学科,它涉及药物代谢和有害的药物反应的预测等方面的内容.个性化药物和个性化治疗发展的关键条件是能够快速简便的检测出病人的遗传多态性.文章综述了药物基因相关问题,细胞色素酶P450和ABCB1转运蛋白的遗传多态性以及检测遗传多态性的相关技术.%Pharmacogenomics is the study of the influence of genetic factors on drug action. It is increasingly important for predicting metabolism and adverse reaction to drugs. A key requirement for the development of individualized medicine or personalized therapy is the ability to rapidly and conveniently test the genetic polymorphisms and mutations in patients. This review addresses the social issues in Pharmacogenomics testing, the cytochrome P450, human ACBC1 genetic polymorphismand some new methods for single nucleotide polymorphism ( SNP ) detection.

  11. EFFECTS OF IN VIVO GENE TRANSDUCTION OF ANTI-MDR1 RIBOZYME IN COMBINATION WITH CHEMOTHERAPY ON MULTIDRUG-RESISTANT HUMAN LYMPHOMA GROWTH IN MICE

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Objective: To study the effect of adenovirus- mediated transfer of anti-MDR1 ribozyme on the reversal of multidrug resistant (MDR) phenotype of P-glycoprotein (P-gp)-positive Daudi human Burkitt lymphoma both in vitro and in vivo. Methods: A recombinant adenovirus expressing 196Rz (Adv-196Rz) was developed and functionally evaluated. SCID mice inoculated subcutaneously (s.c.) with 5×106 Daudi/MDR20 cells were locally treated with Adv-196Rz or mock virus (Adv-Mock) at the multiplicity of infection (MOI) of 400 PFU once a day for 3 consecutive days. Then the mice were intraperitoneally (i.p.) administrated with vincristine (VCR) 450ng/g for 5 consecutive days. Results: In vitro employment of Adv-196Rz was able to interrupt MDR1 transcription, to inhibit P-gp expression and to restore drug sensitivity to VCR of Daudi/MDR20 cells. In vivo, 87.5% (7/8) of Daudi/MDR20-inoculated mice treated with Adv-Mock+ VCR developed palpable tumor by the 6th week and died or were sacrificed (because of tumor weight > 10% of body weight) by the 11th week. In contrast, among 9 Daudi/MDR20-inoculated mice treated with Adv-196Rz + VCR, only 3 developed tumor by the 11th, 13th and 14th week, respectively. 66.7% of mice survived >120 days in tumor-free. The survival difference between the two groups was very significant (P<0.01). Conclusion: Adenovirus- mediated Transfer of 196Rz can revert drug resistance of MDR tumor cells both in vitro and in vivo. Adv-196Rz may prove useful as an adjuvant in the chemotherapy of P-gp mediated MDR human tumors.

  12. Heterologously expressed bacterial and human multidrug resistance proteins confer cadmium resistance to Escherichia coli

    NARCIS (Netherlands)

    Achard-Joris, M; van Saparoea, HBV; Driessen, AJM; Bourdineaud, JP; Bourdineaud, Jean-Paul

    2005-01-01

    The human MDR1 gene is induced by cadmium exposure although no resistance to this metal is observed in human cells overexpressing hMDR1. To access the role of MDR proteins in cadmium resistance, human MDR1, Lactococcus lactis lmrA, and Oenococcus oeni omrA were expressed in an Escherichia coli tolC

  13. HG-829 is a potent noncompetitive inhibitor of the ATP-binding cassette multidrug resistance transporter ABCB1.

    Science.gov (United States)

    Caceres, Gisela; Robey, Robert W; Sokol, Lubomir; McGraw, Kathy L; Clark, Justine; Lawrence, Nicholas J; Sebti, Said M; Wiese, Michael; List, Alan F

    2012-08-15

    Transmembrane drug export mediated by the ATP-binding cassette (ABC) transporter P-glycoprotein contributes to clinical resistance to antineoplastics. In this study, we identified the substituted quinoline HG-829 as a novel, noncompetitive, and potent P-glycoprotein inhibitor that overcomes in vitro and in vivo drug resistance. We found that nontoxic concentrations of HG-829 restored sensitivity to P-glycoprotein oncolytic substrates. In ABCB1-overexpressing cell lines, HG-829 significantly enhanced cytotoxicity to daunorubicin, paclitaxel, vinblastine, vincristine, and etoposide. Coadministration of HG-829 fully restored in vivo antitumor activity of daunorubicin in mice without added toxicity. Functional assays showed that HG-829 is not a Pgp substrate or competitive inhibitor of Pgp-mediated drug efflux but rather acts as a noncompetitive modulator of P-glycoprotein transport function. Taken together, our findings indicate that HG-829 is a potent, long-acting, and noncompetitive modulator of P-glycoprotein export function that may offer therapeutic promise for multidrug-resistant malignancies. PMID:22761337

  14. MDR1 Gene C3435T and C1236T Polymorphisms among Patients with Pharmacoresistant Epilepsy and Healthy Individuals

    Directory of Open Access Journals (Sweden)

    Nodira M. Tuychibaeva

    2014-12-01

    Full Text Available MDR1 gene C3435T and C1236T single-nucleotide polymorphisms (SNPs have been studied in 59 Uzbek patients with epilepsy aged from 1 to 40 years. The patients were resistant to anticonvulsant drugs in therapeutic doses with no remission attained. The disease duration was about two years. The DNA samples were isolated from peripheral blood of patients and healthy individuals. The study found a statistically significant difference in the frequency of the ТТ genotype of the MDR1 gene С3435Т polymorphism, which was associated both with rapid and slow drug metabolism. In the TT genotype group, the share of the patients resistant to the therapy was almost 4.8 times higher than in the control group. Despite high OR=1.9, there were statistically insignificant differences in the frequency of С1236Т SNP. The 3435C – 1236T haplotype of MDR1 gene was associated with an increase the risk of drug-resistance development in epileptic patients.

  15. Association between MDR1 gene polymorphisms and Parkinson's disease in Asian and Caucasian populations: a meta-analysis.

    Science.gov (United States)

    Ahmed, Shiek S S J; Husain, R S Akram; Kumar, Suresh; Ramakrishnan, V

    2016-09-15

    Parkinson's disease (PD) is a complex neurodegenerative disease, its etiology is largely unknown. Studies demonstrate the association of genetic and environment factors in causing neuronal degeneration. Reports suggest that the multi-drug resistance gene (MDR1) plays a vital role in preventing the toxic substance in entering the brain, which is associated with PD. However, the association between the MDR1 polymorphisms (C1236T and C3435T) and its susceptibility to PD is inconclusive. Meta analysis was carried by retrieving literatures from databases to search the case-control studies on the associations between the MRD1 polymorphisms and PD. The pooled odds ratios (ORs) and its 95% confidence intervals (CIs) were calculated using fixed and random model to determine the association between the polymorphisms and PD susceptibility. Significant association was noticed for C1236T polymorphism and PD risk in the recessive model OR=0.80, 95% CI=0.66-0.97. Further, ethnicity based analysis showed significant association for C1236T in allelic model of Asian population and also in the recessive models of both Asian and Caucasian populations. However, insignificant associations were noticed for C3435T in all the four models. Overall, the analysis suggested that MDR1 C1236T polymorphism substantially contribute to Parkinson's disease in the recessive genetic model. PMID:27538645

  16. 靶向MDR1基因的RNAi稳定逆转结肠癌细胞的多药耐药性%Stable reversal of multidrug resistance of colon cancer cells by RNAi targeting MDR1 gene

    Institute of Scientific and Technical Information of China (English)

    夏忠胜; 朱兆华; 陈其奎; 钟英强; 张立勇; 刘仲敏; ADAM Bao-ling

    2009-01-01

    目的:探讨靶向多药耐药蛋白-1 (MDR1)基因的RNA干扰(RNAi)对结肠癌细胞MDR1/P-gp依赖的多药耐药性的稳定逆转作用.方法:分别构建含编码#4029 MDR1 siRNA和#4123 MDR1 siRNA的质粒载体,并转染COLO 320DM结肠癌多药耐药细胞,采用G418筛选克隆细胞,经实时定量RT-PCR及Western blotting鉴定阳性克隆细胞.MTT法检测细胞活力并计算各抗肿瘤药的IC50.流式细胞术检测细胞周期并计算PI/AI值.流式细胞仪测定细胞内adriamycin药物累积浓度.结果:阳性克隆细胞(clone #4029和clone #4123)的MDR1 mRNA和P-gp的表达均被抑制.COLO 320DM结肠癌亲本细胞adriamycin及vincristine的IC50分别为9.616 μmol/L和0.358 μmol/L,而clone #4029的IC50分别降至1.094 μmol/L和0.023 μmol/L(P<0.01),clone #4123的IC50分别降至0.780 μmol/L和0.035 μmol/L(P<0.01).COLO 320DM结肠癌亲本细胞用adriamycin及vincristine处理后其PI/AI值分别为5.68及9.59,而clone #4029的PI/AI值分别降至2.74及3.59(P<0.01),clone #4123的PI/AI值分别降至2.75及3.24(P<0.01).COLO 320DM结肠癌亲本细胞用10 μmol/L adriamycin处理后细胞内adriamycin累积浓度为27.92,而clone #4029及clone #4123细胞内adriamycin累积浓度分别增加至187.24和215.57(P<0.01).结论:稳定转染含编码MDR1 siRNA的质粒载体能稳定逆转结肠癌细胞MDR1/P-gp依赖的多药耐药性.

  17. Different frequencies and effects of ABCB1 T3435C polymorphism on clinical and laboratory features of B cell chronic lymphocytic leukemia in Kurdish patients.

    Science.gov (United States)

    Maroofi, Farzad; Amini, Sabrieh; Roshani, Daem; Ghaderi, Bayazid; Abdi, Mohammad

    2015-04-01

    Finding the effects of gene polymorphism on cancer pathogenesis is very desirable. The ATP-binding cassette is involved in drug metabolism, and the polymorphism of this gene may be an important risk factor in B cell chronic lymphocytic leukemia (B-CLL) or progression and/or response to chemotherapy agents. For the first time, the present study was aimed to evaluate the probable effects of ABCB1 T3435C polymorphism on clinical and laboratory features of Kurdish patients with B-CLL. This descriptive analytical case-control study was performed on 50 B-CLL patients and 100 healthy subjects. Serum levels of beta-2-microglobulin (B2M) and lactate dehydrogenase (LDH) and blood WBC, RBC, Plt and ESR were measured. The T3435C polymorphism of the ABCB1 gene was determined by PCR-RFLP. Concentration of serum and blood markers was significantly higher in the malignant group than in the benign subjects. The CC genotype had the highest frequency (66%) in the patient groups. There are no significant differences between the genotypes and type of treatment. Our results demonstrate the high frequency of C allele of ABCB1 T3435C in B-CLL patients with Kurdish ethnicity. We also show that this polymorphism has a significant risk factor in B-CLL. However, the effect of this polymorphism on clinical and laboratory characteristics of B-CLL patients was not significant. PMID:25586345

  18. Revealing the fate of cell surface human P-glycoprotein (ABCB1): The lysosomal degradation pathway.

    Science.gov (United States)

    Katayama, Kazuhiro; Kapoor, Khyati; Ohnuma, Shinobu; Patel, Atish; Swaim, William; Ambudkar, Indu S; Ambudkar, Suresh V

    2015-10-01

    P-glycoprotein (P-gp) transports a variety of chemically dissimilar amphipathic compounds including anticancer drugs. Although mechanisms of P-gp drug transport are widely studied, the pathways involving its internalization are poorly understood. The present study is aimed at elucidating the pathways involved in degradation of cell surface P-gp. The fate of P-gp at the cell surface was determined by biotinylating cell surface proteins followed by flow cytometry and Western blotting. Our data shows that the half-life of endogenously expressed P-gp is 26.7±1.1 h in human colorectal cancer HCT-15 cells. Treatment of cells with Bafilomycin A1 (BafA1) a vacuolar H+ ATPase inhibitor increased the half-life of P-gp at the cell surface to 36.1±0.5 h. Interestingly, treatment with the proteasomal inhibitors MG132, MG115 or lactacystin alone did not alter the half-life of the protein. When cells were treated with both lysosomal and proteasomal inhibitors (BafA1 and MG132), the half-life was further prolonged to 39-50 h. Functional assays done with rhodamine 123 or calcein-AM, fluorescent substrates of P-gp, indicated that the transport function of P-gp was not affected by either biotinylation or treatment with BafA1 or proteasomal inhibitors. Immunofluorescence studies done with the antibody against lysosomal marker LAMP1 and the P-gp-specific antibody UIC2 in permeabilized cells indicated that intracellular P-gp is primarily localized in the lysosomal compartment. Our results suggest that the lysosomal degradation system could be targeted to increase the sensitivity of P-gp- expressing cancer cells towards chemotherapeutic drugs.

  19. Oral and inhaled corticosteroids: Differences in P-glycoprotein (ABCB1) mediated efflux

    Energy Technology Data Exchange (ETDEWEB)

    Crowe, Andrew, E-mail: a.p.crowe@curtin.edu.au; Tan, Ai May

    2012-05-01

    There is concern that P-glycoprotein mediated efflux contributes to steroid resistance. Therefore, this study examined bidirectional corticosteroid transport and induction capabilities for P-glycoprotein (P-gp) to understand which of the systemic and inhaled corticosteroids interacted with P-gp to the greatest extent. Hydrocortisone, prednisolone, prednisone, methylprednisolone, and dexamethasone represented systemically active drugs, while fluticasone propionate, beclomethasone dipropionate, ciclesonide and budesonide represented inhaled corticosteroids. Aldosterone and fludrocortisone represented mineralocorticoids. All drugs were detected using individually optimised HPLC protocols. Transport studies were conducted through Caco-2 monolayers. Hydrocortisone and aldosterone had efflux ratios below 1.5, while prednisone showed a P-gp mediated efflux ratio of only 1.8 compared to its active drug, prednisolone, with an efflux ratio of 4.5. Dexamethasone and beclomethasone had efflux ratios of 2.1 and 3.3 respectively, while this increased to 5.1 for methylprednisolone. Fluticasone showed an efflux ratio of 2.3. Protein expression studies suggested that all of the inhaled corticosteroids were able to induce P-gp expression, from 1.6 to 2 times control levels. Most of the systemic corticosteroids had higher passive permeability (> 20 × 10{sup −6} cm/s) compared to the inhaled corticosteroids (> 5 × 10{sup −6} cm/s), except for budesonide, with permeability similar to the systemic corticosteroids. Inhaled corticosteroids are not transported by P-gp to the same extent as systemic corticosteroids. However, they are able to induce P-gp production. Thus, inhaled corticosteroids may have greater interactions with other P-gp substrates, but P-gp itself is less likely to influence resistance to the drugs. -- Highlights: ► Inhaled corticosteroids are only weak substrates for P-gp, including budesonide. ► Inhaled corticosteroid potent P-gp inducers especially

  20. Functional impact of ABCB1 variants on interactions between P-glycoprotein and methadone.

    Directory of Open Access Journals (Sweden)

    Chin-Chuan Hung

    Full Text Available Methadone is a widely used substitution therapy for opioid addiction. Large inter-individual variability has been observed in methadone maintenance dosages and P-glycoprotein (P-gp was considered to be one of the major contributors. To investigate the mechanism of P-gp's interaction with methadone, as well as the effect of genetic variants on the interaction, Flp-In™-293 cells stably transfected with various genotypes of human P-gp were established in the present study. The RNA and protein expression levels of human P-gp were confirmed by real-time quantitative RT-PCR and western blot, respectively. Utilizing rhodamine 123 efflux assay and calcein-AM uptake study, methadone was demonstrated to be an inhibitor of wild-type human P-gp via non-competitive kinetic (IC50 = 2.17±0.10 µM, while the variant-type human P-gp, P-gp with 1236T-2677T-3435T genotype and P-gp with 1236T-2677A-3435T genotype, showed less inhibition potency (IC50 = 2.97±0.09 µM and 4.43±1.10 µM, respectively via uncompetitive kinetics. Methadone also stimulated P-gp ATPase and inhibited verapamil-stimulated P-gp ATPase activity under therapeutic concentrations. These results may provide a possible explanation for higher methadone dosage requirements in patients carrying variant-type of P-gp and revealed the possible drug-drug interactions in patients who receive concomitant drugs which are also P-gp substrates.

  1. MDR1 C3435T基因多态性对环孢素体内代谢影响的荟萃分析%Meta-analysis of the effect of MDR1 C3435T polymorphism on cyclosporine pharmacokinetics

    Institute of Scientific and Technical Information of China (English)

    姜志平; 王一任; 徐萍; 刘荣荣; 赵谢兰; 陈方平

    2008-01-01

    目的 通过荟萃分析进一步观察MDR1 C3435T 基因多态性对于环孢素体内代谢的影响.方法 通过Pubmed搜索C3435T 基因多态性对于环孢素体内代谢影响的相关文献,提取AUC0-4, AUC0-12, AUC0-inf,Cmax, CL/F, 和C0等药物动力学参数,使用STATA 9.1软件进行荟萃分析.结果 共有14篇,包括1 036名受试者符合本次荟萃分析的入选条件,荟萃分析显示在C3435T野生型杂合子(CC)中,AUC0-12低于其他基因型的受试者.在白种人中,C3435T野生型杂合子(CC)携带者的C0低于其他基因型的白种受试者.其他药物动力学参数在C3435T各基因型之间未见显著差异.结论 本荟萃分析没有发现MDR1 C3435T 基因多态性对于环孢素体内代谢有较大的影响,但是观察指标的选择是观察结果差异的原因之一;MDR1 C3435T表型和基因型的相关性可能存在种族差异.

  2. CIAPIN1 confers multidrug resistance through up-regulation of MDR-1 and Bcl-L in LoVo/Adr cells and is independent of p53.

    Science.gov (United States)

    Zhang, Ya-Fei; Li, Xiao-Hua; Shi, Yong-Quan; Wu, Yu-Yun; Li, Ning; He, Qiang; Ji, Qing; Wang, Rong-Quan; Yang, Shi-Ming; Fang, Dian-Chun

    2011-04-01

    Recent investigations discovered that CIAPIN1 might be another drug resistance-associated molecule in cancer cells. However, the underlying mechanisms of CIAPIN1-related multidrug resistance (MDR) remain elusive. In the present study, we investigated the role and possible mechanisms of CIAPIN1 in MDR of human colon carcinoma LoVo/Adr cells which express the wild-type p53 gene. By using small interference RNA and gene transfection techniques, we found that knockdown of CIAPIN1 expression re-sensitized LoVo/Adr cells to anti-cancer drugs and up-regulation of CIAPIN1 in sensitive LoVo cells resulted in a distinct MDR phenotype. We further revealed that CIAPIN1 conferred the MDR phenotype in LoVo/Adr cells through up-regulating expression of MDR-1 (P-gp) and Bcl-xL. Finally, by analyzing the effect of inactivation of wild-type p53 on CIAPIN1-induced up-regulation of P-gp and Bcl-xL, we determined that CIAPIN1 could exhibit its MDR-related function independently of the p53 signaling pathway. Overall, the results presented here further suggest that over-expression of CIAPIN1 is an important mechanism of drug resistance in human cancers, even if not the sole one.

  3. Cinnamaldehyde Derivative (CB-PIC Sensitizes Chemo-Resistant Cancer Cells to Drug-Induced Apoptosis via Suppression of MDR1 and its Upstream STAT3 and AKT Signalling

    Directory of Open Access Journals (Sweden)

    Jianzhong Xi

    2015-03-01

    Full Text Available Background/Aims: Our group reported that cinnamaldehyde derivative, (E-4-((2-(3-oxopop-1-enylphenoxymethylpyridinium malonic acid (CB-PIC induced apoptosis in hypoxic SW620 colorectal cancer cells via activation of AMP-activated protein kinase (AMPK and extracellular signal regulated kinase (ERK. Herein, sensitizing effect of CB-PIC was investigated in resistant cancer cells such as paclitaxel (PT resistant lung cancer cells (H460/PT, and Adriamycin (Adr resistant breast cancer (MCF7/Adr and colon cancer (HCT15/cos cells. Methods: Various drug resistant cell lines were treated with CB-PIC, and the signalling pathway and functional assay were explored by Western blot, Rhodamine assay, FACS, RT-PCR and MTT assay. Results: We found that CB-PIC effectively exerted cytotoxicity, increased sub G1 population and the cleaved form of poly (ADP-ribose polymerase (PARP and caspase 9 in drug resistant cancer cells. Furthermore, CB-PIC sensitized resistant cancer cells to adriamycin via downregulation of survival proteins such as survivin, Bcl-xL and Bcl-2, along with MDR1 suppression leading to accumulation of drug in the intracellular region. Of note, CB-PIC transcriptionally decreased MDR1 expression via suppression of STAT3 and AKT signalling in three resistant cancer cells with highly expressed P-glycoprotein. Nonetheless, CB-PIC did not affect transport activity of P-glycoprotein in a short time efflux assay, while epigallocatechin gallate (EGCG accumulated Rhodamine 123 into intracellular region of cell by direct inhibition of MDR1 transport activity. Conclusions: These data demonstrate that CB-PIC suppresses the P-glycoprotein expression through inhibition of STAT3 and AKT signalling to overcome drug resistance in chemo-resistant cancer cells as a potent chemotherapeutic sensitizer.

  4. Association of MDR1 gene polymorphisms with the risk of hepatocellular carcinoma in the Chinese Han population

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Jian [Tianjin Medical University, Tianjin (China)

    2013-03-15

    The multidrug resistance 1 gene (MDR1) is an important candidate gene for influencing susceptibility to hepatocellular carcinoma (HCC). The objective of the present study was to evaluate the association of MDR1 polymorphisms with the risk of HCC in the Chinese Han population. A total of 353 HCC patients and 335 healthy subjects were enrolled in the study. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), created restriction site-PCR (CRS-PCR) and DNA sequencing methods were used to identify MDR1 gene polymorphisms. Two allelic variants (c.335T>C and c.3073A>C) were detected. The CC genotype of the c.335T>C polymorphism was associated with an increased risk of developing HCC compared to the TT genotype (OR = 2.161, 95%CI = 1.350-3.459, χ{sup 2} = 10.55, P = 0.0011). The risk of HCC was significantly higher for the CC genotype in the c.3073A>C polymorphism compared to the AA genotype in the studied populations (CC vs AA: OR = 2.575, 95%CI = 1.646-4.028, χ{sup 2} = 17.64, P < 0.0001). The C allele of the c.335T>C and c.3073A>C variants may contribute to the risk of HCC (C vs T of c.335T>C: OR = 1.512, 95%CI = 1.208-1.893, χ{sup 2} = 13.07, P = 0.0003, and C vs A of c.3073A>C: OR = 1.646, 95%CI = 1.322-2.049, χ{sup 2} = 20.03, P < 0.0001). The c.335T>C and c.3073A>C polymorphisms of the MDR1 gene were associated with the risk of occurrence of HCC in the Chinese Han population. Further investigations are needed to confirm these results in larger different populations.

  5. The Effect of ABCB1 C3435T Polymorphism on Cyclosporine Dose Requirements in Kidney Transplant Recipients: A Meta-Analysis.

    Science.gov (United States)

    Lee, Jun; Wang, Rongrong; Yang, Yuan; Lu, Xiaoyang; Zhang, Xingguo; Wang, Linrun; Lou, Yan

    2015-08-01

    Cyclosporine A (CsA) is a substrate of the multi-drug efflux pump P-glycoprotein (P-gp) encoded by ABCB1. Among the various single nucleotide polymorphisms (SNPs) of ABCB1, C3435T has been extensively investigated to determine the relationship with the pharmacokinetics of CsA. However, the results are controversial. This meta-analysis was designed to evaluate the influence of C3435T SNP on the dose-adjusted trough (C0 /D) and peak (Cmax /D) concentrations of CsA. Based on a literature search of four authoritative databases, 13 studies since 2001 concerning 1293 kidney transplant recipients were included. The results indicated a significant difference of C0 /D and Cmax /D between 3435CC and 3435TT genotype carriers (weighted mean difference (WMD) of C0 /D: 4.18 (ng ml(-1))/(mg kg(-1)), 95% CIs: 1.00-7.37, p = 0.01; WMD of Cmax /D: 20.85 (ng ml(-1))/(mg kg(-1)), 95% CIs: 2.25-39.46, p = 0.03). Subgroup analysis by ethnicity demonstrated that C0 /D was lower in Asian CC versus TT genotype carriers (WMD = 10.32 (ng ml(-1))/(mg kg(-1)), 95% CIs: 4.78-15.85, p = 0.0003) but did not vary by genotype for Caucasian recipients. Moreover, significant variation of C0 /D was found at 1 week and 1-3 months after transplantation between CC and TT genotype carriers. Therefore, this meta-analysis showed a correlation between ABCB1 C3435T polymorphism and the dose-adjusted concentration of CsA. Patients with 3435CC genotype will require a higher dose of CsA to achieve target therapeutic concentrations when compared with 3435TT carriers after kidney transplantation, especially in the Asian population and especially during the early and middle time periods after transplantation. PMID:25536375

  6. Homogeneously staining region in anthracycline-resistant HL-60/AR cells not associated with MDR1 amplification.

    Science.gov (United States)

    Gervasoni, J E; Taub, R N; Yu, M T; Warburton, D; Sabbath, M; Gilleran, S; Coppock, D L; D'Alessandri, J; Krishna, S; Rosado, M

    1992-10-01

    Anthracycline-resistant HL-60/AR cells and their drug-sensitive HL-60/S counterparts were characterized by karyotypic analysis and examined for the overexpression of DNA and mRNA sequences coding for P-glycoprotein (Pgp). The HL-60/S cells were karyotypically stable over a 5-year period of study (1986-1991), except for an additional small Giemsa-positive band noted at 7q22 in cultures harvested in 1987, but not in 1986. This change did not affect drug sensitivity. The drug-resistant HL-60/AR cells examined in 1986, 1987, and 1991 demonstrated a very stable karyotype. The most striking feature was a large homogeneously staining region in the long arm of chromosome 7 (7q11.2), and translocation of the remainder of the long arm to another centromere. Other changes in the HL-60/AR cells included inversion in 9q, partial deletion of the short arm of chromosome 10p, addition of material to the p arm of der(16), loss of chromosome 22, and the appearance of a new marker chromosome. Both HL-60/S and the HL-60/AR cells were found not to amplify DNA or mRNA sequences coding for the Pgp. Thus, although the HL-60/AR cells possess the classical multidrug resistance phenotype and demonstrate a homogeneously staining region near the region of the MDR1 gene, their resistance is due to mechanisms other than those coded for by MDR1.

  7. Design and synthesis of human ABCB1 (P-glycoprotein) inhibitors by peptide coupling of diverse chemical scaffolds on carboxyl and amino termini of (S)-valine-derived thiazole amino acid.

    Science.gov (United States)

    Singh, Satyakam; Prasad, Nagarajan Rajendra; Chufan, Eduardo E; Patel, Bhargav A; Wang, Yi-Jun; Chen, Zhe-Sheng; Ambudkar, Suresh V; Talele, Tanaji T

    2014-05-22

    P-glycoprotein (P-gp) serves as a therapeutic target for the development of multidrug resistance reversal agents. In this study, we synthesized 21 novel compounds by peptide coupling at corresponding carboxyl and amino termini of (S)-valine-based bis-thiazole and monothiazole derivatives with diverse chemical scaffolds. Using calcein-AM efflux assay, we identified compound 28 (IC50 = 1.0 μM) carrying 3,4,5-trimethoxybenzoyl and 2-aminobenzophenone groups, respectively, at the amino and carboxyl termini of the monothiazole zwitter-ion. Compound 28 inhibited the photolabeling of P-gp with [(125)I]-iodoarylazidoprazosin with IC50 = 0.75 μM and stimulated the basal ATP hydrolysis of P-gp in a concentration-dependent manner (EC50 ATPase = 0.027 μM). Compound 28 at 3 μM reduced resistance in cytotoxicity assay to paclitaxel in P-gp-expressing SW620/Ad300 and HEK/ABCB1 cell lines. Biochemical and docking studies showed site-1 to be the preferable binding site for 28 within the drug-binding pocket of human P-gp.

  8. Tissue-specific alterations in expression and function of P-glycoprotein in streptozotocininduced diabetic rats

    Institute of Scientific and Technical Information of China (English)

    Lu-lu ZHANG; Guang-ji WANG; Lin XIE; Liang LU; Shi JIN; Xin-yue JING; Dan YAO; Nan HU; Li LIU; Ru DUAN; Xiao-dong LIU

    2011-01-01

    Aim: To investigate the changes of expression and function of P-glycoprotein (P-GP) in cerebral cortex, hippocampus, liver, intestinal mucosa and kidney of streptozocin-induced diabetic rats.Methods: Diabetic rats were prepared via a single dose of streptozocin (65 mg/kg, ip). Abcb1/P-GP mRNA and protein expression levels in tissues were evaluated using quantitative real time polymerase chain reaction (QRT-PCR) analysis and Western blot, respectively.P-GP function was investigated via measuring tissue-to-plasma concentration ratios and body fluid excretion percentages of rhodamine 123.Results: In 5- and 8-week diabetic rats, Abcb1a mRNA levels were significantly decreased in cerebral cortices and intestinal mucosa,but dramatically increased in hippocampus and kidney. In liver, the level was increased in 5-week diabetic rats, and decreased in 8-week diabetic rats. Abcb1b mRNA levels were increased in cerebral cortex, hippocampus and kidney, but reduced in liver and intestinal mucosa in the diabetic rats. Western blot results were in accordance with the alterations of Abcb1a mRNA levels in most tissues examined. P-GP activity was markedly decreased in most tissues of diabetic rats, except kidney tissues.Conclusion: Alterations in the expression and function of Abcb1/P-GP under diabetic conditions are tissue specific, Abcb1 specific and diabetic duration-dependent.

  9. Reversing multidrug resistance by RNA interference through the suppression of MDR1 gene in human hepatoma cells

    Institute of Scientific and Technical Information of China (English)

    Xiao-Ping Chen; Qi wang; Jian Guan; Zhi-Yong Huang; Wan-Guang Zhang; Bi-Xiang Zhang

    2006-01-01

    AIM: To reverse the multidrug resistance (MDR) by RNA interference (RNAi)-mediated MDR1 suppression in hepatoma cells.METHODS: For reversing MDR by RNAi technology, two different short hairpin RNAs (shRNAs) were designed and constructed into pGenSil-1 plasmid, respectively. They were then transfected into a highly adriamycin-resistant HepG2 hepatoma cell line (HepG2/ADM). The RNAi effect on MDR was evaluated by real-time PCR, cell cytotoxicity assay and rhodamine 123 (Rh123) efflux assy.RESULTS: The stably-transfected clones showed various degrees of reversal of MDR phenotype. Surprisingly, the MDR phenotype was completely reversed in two transfected clones.CONCLUSION: MDR can be reversed by the shRNAmediated MDRI suppression in HepG2/ADM cells, which provides a valuable clue to make multidrug-resistant hepatoma cells sensitive to anti-cancer drugs.

  10. The ABCB1, rs9282564, AG and TT Genotypes and the COMT, rs4680, AA Genotype are less frequent in Deceased Patients with Opioid Addiction (DOA) than in Living Patients with Opioid Addiction (LOA)

    DEFF Research Database (Denmark)

    Christoffersen, Dorte J; Damkier, Per; Feddersen, Søren;

    2016-01-01

    because morphine and methadone more readily cross the blood-barrier in these subjects due to a lower efflux transporter activity of the ABCB1 (p-glycoprotein) transporter. Our results did not support this hypothesis, since no statistically significant difference (p=0.506) in the frequency of the TT...... genotype of rs1045642 was observed between the DOA, LOA and HV cohorts. However, for another ABCB1 variant, rs9282564, we found that the frequencies of the AG and TT genotypes were 13, 21 and 25% in DOA, LOA and HV, respectively, and after correcting for age, sex and multiple testing, the differences...

  11. The role of mdr1a P-glycoprotein in the biliary and intestinal secretion of doxorubicin and vinblastine in mice.

    Science.gov (United States)

    van Asperen, J; van Tellingen, O; Beijnen, J H

    2000-03-01

    Drug-transporting P-glycoproteins are abundantly present in the liver and the intestinal wall. We have now investigated their role in the biliary and intestinal secretion of the anticancer drugs doxorubicin (unlabeled: 5 mg/kg) and vinblastine ((3)H-labeled: 1 mg/kg) i.v. administered to wild-type and mdr1a P-glycoprotein knockout [mdr1a(-/-)] mice. At 90 min after drug administration, levels of unchanged drug and metabolites in plasma, intestinal contents, and bile were determined by high-performance liquid chromatography and radioactivity by liquid scintillation counting. The bile of both wild-type and mdr1a(-/-) mice contained only minor amounts of unchanged vinblastine, whereas the total biliary secretion of unknown (3)H-labeled breakdown products was about 25 to 30% of the dose. The direct secretion of unchanged vinblastine through the gut wall was 6.7 and 3.3% of the dose in wild-type and mdr1a(-/-) mice, respectively. The biliary secretion of unchanged doxorubicin decreased from 13.3% of the dose to only 2.4% in the absence of mdr1a P-glycoprotein. Approximately 10% of the dose was secreted as unchanged doxorubicin into the intestinal contents of both types of mice. Thus, the absence of mdr1a P-glycoprotein affects the fate of vinblastine chiefly by diminishing secretion into the lumen of the small intestine, whereas it affects the fate of doxorubicin chiefly by diminishing secretion of parent drug into bile.

  12. pHluorin enables insights into the transport mechanism of antiporter Mdr1: R215 is critical for drug/H+ antiport.

    Science.gov (United States)

    Redhu, Archana Kumari; Khandelwal, Nitesh Kumar; Banerjee, Atanu; Moreno, Alexis; Falson, Pierre; Prasad, Rajendra

    2016-10-01

    Multidrug resistance 1 (MDR1) is a member of the major facilitator superfamily that contributes to MDR of Candida albicans This antiporter belongs to the drug/H(+) antiporter 1 family, pairing the downhill gradient of protons to drug extrusion. Hence, drug efflux from cytosol to extracellular space and the parallel import of H(+) towards cytosol are inextricably linked processes. For monitoring the drug/H(+) antiporter activity of Mdr1p, we developed a new system, exploiting a GFP variant pHluorin, which changes its fluorescence properties with pH. This enabled us to measure the cytosolic pH correlated to drug efflux. Since protonation of charged residues is a key step in proton movement, we explored the role of all charged residues of the 12 transmembrane segments (TMSs) of Mdr1p in drug/H(+) transport by mutational analysis. This revealed that the conserved residue R(215), positioned close to the C-terminal end of TMS-4, is critical for drug/H(+) antiport, allowing protonation over a range of pH, in contrast with its H(215) or K(215) variants that failed to transport drugs at basic pH. Mutation of other residues of TMS-4 highlights the role of this TMS in drug transport, as confirmed by in silico modelling of Mdr1p and docking of drugs. The model points to the importance of R(215) in proton transport, suggesting that it may adopt two main conformations, one oriented towards the extracellular face and the other towards the centre of Mdr1p. Together, our results not only establish a new system for monitoring drug/H(+) transport, but also unveil a positively charged residue critical to Mdr1p function.

  13. Astrocytes drive upregulation of the multidrug resistance transporter ABCB1 (P-Glycoprotein) in endothelial cells of the blood-brain barrier in mutant superoxide dismutase 1-linked amyotrophic lateral sclerosis.

    Science.gov (United States)

    Qosa, Hisham; Lichter, Jessica; Sarlo, Mark; Markandaiah, Shashirekha S; McAvoy, Kevin; Richard, Jean-Philippe; Jablonski, Michael R; Maragakis, Nicholas J; Pasinelli, Piera; Trotti, Davide

    2016-08-01

    The efficacy of drugs targeting the CNS is influenced by their limited brain access, which can lead to complete pharmacoresistance. Recently a tissue-specific and selective upregulation of the multidrug efflux transporter ABCB1 or P-glycoprotein (P-gp) in the spinal cord of both patients and the mutant SOD1-G93A mouse model of amyotrophic lateral sclerosis (ALS), a fatal neurodegenerative disease that prevalently kills motor neurons has been reported. Here, we extended the analysis of P-gp expression in the SOD1-G93A ALS mouse model and found that P-gp upregulation was restricted to endothelial cells of the capillaries, while P-gp expression was not detected in other cells of the spinal cord parenchyma such as astrocytes, oligodendrocytes, and neurons. Using both in vitro human and mouse models of the blood-brain barrier (BBB), we found that mutant SOD1 astrocytes were driving P-gp upregulation in endothelial cells. In addition, a significant increase in reactive oxygen species production, Nrf2 and NFκB activation in endothelial cells exposed to mutant SOD1 astrocytes in both human and murine BBB models were observed. Most interestingly, astrocytes expressing FUS-H517Q, a different familial ALS-linked mutated gene, also drove NFκB-dependent upregulation of P-gp. However, the pathway was not dependent on oxidative stress but rather involved TNF-α release. Overall, these findings indicated that nuclear translocation of NFκB was a converging mechanism used by endothelial cells of the BBB to upregulate P-gp expression in mutant SOD1-linked ALS and possibly other forms of familial ALS. GLIA 2016 GLIA 2016;64:1298-1313. PMID:27158936

  14. Acute kidney injury in a preterm infant homozygous for the C3435T polymorphism in the ABCB1 gene given oral morphine

    Science.gov (United States)

    Pogliani, Laura; Mameli, Chiara; Cattaneo, Dario; Clementi, Emilio; Meneghin, Fabio; Radice, Sonia; Bruno, Simona; Zuccotti, Gian Vincenzo

    2012-01-01

    A 34-week infant born from a mother with a history of drug abuse developed neonatal abstinence syndrome (NAS) in the first hours of life. Urine drug screening was positive for cocaine and heroin. The infant developed acute kidney injury and bilateral hydronephrosis while receiving oral morphine for control of NAS. Cessation of morphine therapy and urinary catheterization resulted in a rapid and complete resolution of the symptoms. Our patient was homozygous for the C3435T polymorphism in the ABCB1 gene, a polymorphism previously associated with impaired P-glycoprotein activity. We hypothesize that acute renal toxicity was related to accumulation of morphine within urothelial cells due to genetically determined impaired P-glycoprotein activity. PMID:26019822

  15. EXPRESSION AND CLINICAL SIGNIFICANCE OF MULTIDRUG RESISTANCE GENE AND MULTIDRUG RESISTANCE-ASSOCIATED PROTEIN GENE IN ACUTE LEUKEMIA

    Institute of Scientific and Technical Information of China (English)

    LAI Yong-rong; MA Jie; LU Yu-ying; NU Wei-lin; XIANG Zhi-fu

    1999-01-01

    Objective: To evaluate the expression and clinical significance of multidrug resistance gene (mdr1) and multidrug resistance-associated protein (MRP) gene in acute leukemia. Methods: The expression of mdr1 and MRP assay in 55 patients with acute leukemia (AL) by reverse transcription polymerase chain reaction (RT-PCR).Results: The mdr1 and MRP gene expression levels in the relapsed AL and the blastic plastic phases of CML were significantly higher than those in the newly diagnostic AL and controls. The mdr1 and MRP gene expression levels in the clinical drug-resistant group were significantly higher than those in the non-drug-resistant group. The complete remission (CR) rate in patients with high mdr1 expression (14.3%) was significantly lower than that with low mdr1 expression (57.5%); similarly the CR rate in patients with high MRP level was also lower than that with low MRP level. Using both high expression of mdr1 and MRP gene as the indicator for evaluating multidrug resistance (MDR),the positive predictive value and accuracy increased in comparison with single gene high expression. Conclusion:Elevated level of mdr1 or MRP gene expression might be unfavorable prognostic factors for AL patient and may be used as an important index for predicting drug-resistance and relapse in AL patient. Measuring both mdr1 and MRP gene expression would increase accuracy and sensibility of evaluating MDR in acute leukemia.

  16. The role of {sup 99m}Tc-MIBI scintigraphy in the assessment of MDR1 overexpression in patients with musculoskeletal sarcomas: comparison with therapy response

    Energy Technology Data Exchange (ETDEWEB)

    Burak, Z.; Erinc, R.; Oezcan, Z.; Dirlik, A. [Dept. of Nuclear Medicine, Ege University Medical Faculty, Bornova (Turkey); Ersoy, Oe.; Basdemir, G. [Dept. of Pathology, Ege University Medical Faculty, Izmit (Turkey); Moretti, J.-L. [Service de Medecine Nucleaire et Biophysique, Univ. Paris 8 (France); Sabah, D. [Dept. of Orthopaedics, Ege University Medical Faculty, Izmir (Turkey)

    2001-09-01

    The occurrence of multidrug resistance (MDR), which is in part due to the overexpression of P-glycoprotein (Pgp), is a major problem in neoadjuvant therapy of malignant musculoskeletal tumours. The aim of this study was to investigate the role of technetium-99m hexakis-2-methoxyisobutylisonitrile ({sup 99m}Tc-MIBI) scintigraphy for functional imaging of the MDR1 phenotype in patients with musculoskeletal sarcomas. We aimed to compare {sup 99m}Tc-MIBI uptake and washout kinetics with the expression of Pgp and with chemotherapy response. Twenty-five patients (16 males and 9 females, aged between 8 and 65 years) with malignant musculoskeletal tumours were studied. After injection of 555-740 MBq {sup 99m}Tc-MIBI, dynamic flow images of the involved area were obtained for 3 min, and planar images were acquired at 10 min and 1 h. From the dynamic images, a tumour perfusion index (TPI) was obtained using Patlak-Rutland analysis. Tumour to background (T/B) ratios of both early and delayed images and percent wash-out rate (WR%) of {sup 99m}Tc-MIBI were calculated. Immunohistochemical analysis of Pgp was performed on biopsy specimens and the degree of expression was graded according to a semiquantitative scoring system, from 0 to 6. After neoadjuvant therapy, tumour response was assessed by examining the ratio of viable cells and by detecting percent necrosis. Scintigraphic results were compared with Pgp status and therapy response. Irrespective of the Pgp status, all patients showed significant perfusion and {sup 99m}Tc-MIBI uptake in early images. There was not a significant correlation between T/B ratios of early and delayed images and Pgp expression. We observed a positive correlation between WR% and Pgp status (r=0.61, P<0.01), and the wash-out rate of {sup 99m}Tc-MIBI was significantly higher in patients with high Pgp expression than in those with a low Pgp score (33%{+-}9% vs 17%{+-}9%). Therapy response was determined in 21 of 25 patients, and in only 5 of 21 cases

  17. Selected ABCB1, ABCB4 and ABCC2 Polymorphisms Do Not Enhance the Risk of Drug-Induced Hepatotoxicity in a Spanish Cohort

    Science.gov (United States)

    Ulzurrun, Eugenia; Stephens, Camilla; Ruiz-Cabello, Francisco; Robles-Diaz, Mercedes; Saenz-López, Pablo; Hallal, Hacibe; Soriano, German; Roman, Eva; Fernandez, M. Carmen; Lucena, M. Isabel; Andrade, Raúl J.

    2014-01-01

    Background and Aims Flawed ABC transporter functions may contribute to increased risk of drug-induced liver injury (DILI). We aimed to analyse the influence of genetic variations in ABC transporters on the risk of DILI development and clinical presentations in a large Spanish DILI cohort. Methods A total of ten polymorphisms in ABCB1 (1236T>C, 2677G>T,A, 3435T>C), ABCB4 (1954A>G) and ABCC2 (−1774G>del, −1549A>G, −24C>T, 1249G>A, 3972C>T and 4544G>A) were genotyped using Taqman 5′ allelic discrimination assays or sequencing in 141 Spanish DILI patients and 161 controls. The influence of specific genotypes, alleles and haplotypes on the risk of DILI development and clinical presentations was analysed. Results None of the individual polymorphisms or haplotypes was found to be associated with DILI development. Carriers homozygous for the ABCC2 −1774del allele were however only found in DILI patients. Hence, this genotype could potentially be associated with increased risk, though its low frequency in our Spanish cohort prevented a final conclusion. Furthermore, carriers homozygous for the ABCC2 −1774G/−1549A/−24T/1249G/3972T/4544G haplotype were found to have a higher propensity for total bilirubin elevations when developing DILI. Conclusions Our findings do not support a role for the analysed polymorphisms in the ABCB1, ABCB4 and ABCC2 transporter genes in DILI development in Spanish patients. The ABCC2 −1774deldel genotype was however restricted to DILI cases and could potentially contribute to enhanced DILI susceptibility. PMID:24732756

  18. ABCB1基因位点(C3435T)多态性与癫痫耐药关联性的Meta分析%Meta analysis of relationship between polymorphism of gene site (C3435T) of ABCB1 and antiepileptic drug resistant

    Institute of Scientific and Technical Information of China (English)

    彭锐; 张洪; 张英; 魏丹芸

    2015-01-01

    目的:探讨ABCB1的基因位点(C3435T)多态性与癫痫耐药关联性。方法计算机检索Pubmed、Science direct、Wiley online library、Web of Science、中国知网、万方数据库和维普中文科技期刊数据库,纳入抗癫痫药耐药与抗癫痫药敏感的随机对照试验,同时查阅检索结果中所附相似文献及参考文献,检索文献均为建库至2014年6月15日。由两名评价员单独进行文献筛选及资料提取,采用RevMan 5.0软件进行Meta分析及其他统计学分析。结果共纳入文献10篇,癫痫患者中耐药815例,敏感976例。Meta分析结果显示,C3435T位点多态性在等位基因模型、显性模型、隐性模型、共显性模型(CC/TT组)下整体效应差异有统计学意义(P0.05);而印度地区ABCB1 C3435T位点基因多态性与癫痫耐药在等位基因模型和隐性基因模型下整体效应差异有统计学意义(P0.05). In the allele gene model, OR=0.70, 95%CI (0.54, 0.93);recessive gene model, OR=0.72, 95%CI (0.49, 1.07). Conclusion ABCB1 C3435T loci polymor-phism dose not relate to the antiepileptic drug resistant among Chinese; but ABCB1 C3435T loci polymorphism relates to the antiepileptic drug resistant among Indian.

  19. Impact of BCRP/MXR, MRP1 and MDR1/P-Glycoprotein on thermoresistant variants of atypical and classical multidrug resistant cancer cells

    DEFF Research Database (Denmark)

    Stein, Ulrike; Lage, Hermann; Jordan, Andreas;

    2002-01-01

    The impact of the ABC transporters breast cancer resistance protein/mitoxantrone resistance associated transporter (BCRP/MXR), multidrug resistance-associated protein 1 (MRP1) and multidrug resistance gene-1/P-glycoprotein (MDR1/PGP) on the multidrug resistance (MDR) phenotype in chemoresistance...

  20. The association of C3435T single-nucleotide polymorphism, Pgp-glycoprotein gene expression levels and carbamazepine maintenance dose in patients with epilepsy

    Directory of Open Access Journals (Sweden)

    Sterjev Z

    2012-04-01

    Full Text Available Zoran Sterjev1, Gordana Kiteva Trencevska2, Emilija Cvetkovska2, Igor Petrov2, Igor Kuzmanovski2, Jasmina T Ribarska3, Aleksandra K Nestorovska1, Nadica Matevska1, Zorica Naumovska1, Suzana Jolevska-Trajkovic3, Aleksandar Dimovski1, Ljubica Suturkova11Institute of Pharmaceutical Chemistry, Faculty of Pharmacy Skopje, Republic of Macedonia; 2Clinic of Neurology, Faculty of Medicine, Skopje, Republic of Macedonia; 3Institute of Pharmaceutical Analysis, Faculty of Pharmacy Skopje, Republic of MacedoniaAbstract: The ABCB1 gene encodes the P-glycoprotein (Pgp protein, which is thought to transport various antiepileptic drugs. The single nucleotide polymorphism (SNP (C3435T in exon 26 of this gene correlates with the altered expression levels of P-glycoprotein, range of drug response and clinical conditions. In order to investigate the influence of this polymorphism on the susceptibility to and efficacy of carbamazepine therapy, we evaluated the allelic frequency and genotype distribution of this variant in 162 epilepsy patients from the Republic of Macedonia. Statistically significant differences were detected neither in the allelic frequency and genotype distribution between carbamazepine-resistant and carbamazepine-responsive epilepsy patients nor between the subgroups of carbamazepine (CBZ-responsive patients treated with different CBZ doses. However, the T-allele was enriched in CBZ-responsive patients who required higher maintenance CBZ doses, This observation was substantiated by the findings that the median total plasma levels were the lowest in patients with CC (20 µmol/L followed by CT (23 µmol/L and TT (29 µmol/L genotypes. Patients with a CC genotype also had a higher likelihood of response compared to patients with CT or TT genotypes over a wide range (400–1000 mg/day of initial doses of CBZ. The T allele showed a reduced expression of ~5% compared to the C allele in peripheral blood mononuclear cells in heterozygotes for the variant

  1. ABCB1基因 rs1045642位点多态性与文拉法辛疗效的关联研究%Relationship between ABCB1 rs1045642 polymorphism and therapeutic effect of venlafaxine in patients with depression

    Institute of Scientific and Technical Information of China (English)

    李文平; 张志珺; 孙晓燕; 高琪; 耿磊钰; 浦梦佳; 史艳艳; 徐治

    2013-01-01

    Objective: To investigate the role of ABCB1 rs1045642 polymorphism in antidepressant response . Methods:Eighty-nine Chinese Han patients received venlafaxine 75-150 mg for at least 6 weeks,of which 88 cases were followed up for 8 weeks.The Hamilton depression scale-17(HAMD-17) was used to evaluate the severity of depressive symptoms and the therapeutic effects .The single nucleotide polymorphisms ( SNPs ) rs1045642 of ABCB1 gene was detected using gene chips , then the associations of single locus with treatment response were analyzed using Unphased 3.0.13.Results: (1) There were no significant differences of gender ,age,years of education,family history, episode times, and the baseline scores of HAMD-17 between responders and non-responders (all P>0.05).(2) There were also no significant differences of gender ,age,years of education,family history ,episode times and baseline scores of HAMD-17 between remitters and non-remitters ( all P >0.05 ) . (3) Single locus association analysis: The SNPs rs1045642 genotype and allele distribution frequency of ABCB1 gene between responders and non-responders and between remitters and non-remitters had no significant differences ( all P>0.05 ) .Conclusion:There is no ABCB1 rs1045642 polymorphism associated with antidepressant response , it require replication in more homogeneous and larger samples .%目的:探讨ABCB1基因rs1045642位点多态性对抗抑郁剂文拉法辛疗效的影响。方法:纳入统计的89例抑郁症患者服用抗抑郁剂文拉法辛75~150 mg并随访6周,其中88例随访8周。使用汉密尔顿抑郁17项量表( HAMD-17)评定抑郁症状的严重程度和治疗效果。采用基因芯片检测ABCB1基因的单核苷酸多态性( SNPs) rs1045642,并通过Unphased3.0.13软件分析rs1045642位点与文拉法辛疗效的关联性。结果:(1)6周有效组和无效组间在性别、年龄、教育程度、家族史、发病次数及HAMD-17项基线分数

  2. Importancia pronóstica de la expresión de MDR-1 en la leucemia mieloblástica aguda

    OpenAIRE

    J. Arbelbide; H. Garcia Rivello; M. C. Tacchi; D. Fantl; M. P. Cardenas; D. Penchasky; S. Viñuales; A. Morandi; E. M. Nucifora

    2003-01-01

    Una proporción importante de pacientes con leucemia mieloblástica aguda (LMA) presentan recaída o resistencia con el tratamiento. Uno de los mecanismos involucrados en la resistencia a drogas, es la presencia de la glicoproteína P 170 (gp-P 170) resultante de la expresión del gen MDR-1 sobre las células leucémicas. El objetivo de este trabajo es valorar el impacto pronóstico de la expresión de MDR-1 en una población de pacientes tratados por LMA. Se evaluó retrospectivamente la expresión de M...

  3. The (SNP) of multi-drug resistance 1 protein (MDR1,P-glycoprotein) in Chinese Han population

    Institute of Scientific and Technical Information of China (English)

    DanLI; Guo-liangZHANG; XinWANG; Xiu-yunBU

    2004-01-01

    AIM: To investigate the single nucleotide polymorphism (SNP) of multi-drug resistance 1 protein (MDR1, P-glycoprotein) in the Chinese Han population. METHODS'. DNA was extracted from 200 p,L heparin-anticoagulated whole blood using QIAamp Blood Kit. A polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) was used for the detection of C3435T SNP. The PCR product of 248 bp was digested with

  4. MDR1基因多态性对替米沙坦血药浓度和药动力学影响研究%Effects of MDR1 Gene C3435T polymorphism on bloold concentration and pharmacokinetics of telmisartan

    Institute of Scientific and Technical Information of China (English)

    程茂良; 王珏

    2013-01-01

    目的:探讨健康志愿者和高血压患者的多药耐药基因(Multidrug resistance 1 gene,MDR1) C3435T基因多态性对替米沙坦血药浓度和药动学的影响.方法:采用聚合酶链反应(Polymerase chain reaction,PCR)和限制性内切片段多态性(Restriction fragment length polymorphism,RFLP)的方法对19名健康志愿者和61例高血压患者进行MDR1基因分型;使用HPLC-MS法测定志愿者单剂量口服40 mg替米沙坦48 h内血药浓度和高血压患者的稳态血药浓度.比较替米沙坦在不同基因型的健康志愿者单剂量药动学及高血压患者稳态血药浓度的差异.结果:在61例高血压患者中,MDRlCC型纯合子频率39.34%,TT型纯合子频率11.48%,CT型杂合子频率49.18%,C3435T发生率在健康人群和高血压患者之间没有明显的差异,C3435T的三个不同基因型志愿者Cmax、tmax、t1/2、AUC0-48、AUC0-∞和CL差异无统计学意义(P>0.05).三个基因型高血压患者的稳态血药浓度差异无统计学意义(P>0.05).结论:MDR1C3435T基因多态性对替米沙坦的血药浓度和药动学无影响.%AIM:To determine the effects of MDR1C3435T on the pharmacokinetics of telmisartan in healthy Chinese volunteers and blood concentration in hypertension patients.METHODS:The genotype on MDR1C3435T in 19 healthy Chinese volunteers who were received a single oral dose of 40 ng telmisartan and 61 hypertension patients who were received oral of 40 mg telmisartan every day after a month was detected by PCR RFLP method,the relationship of MDR1C3435T polymorphism and steady-state blood concentrations of telmisartan were determinated by HPLC-MS.The pharmacokinetics of telmisartan in health volunteers and steady-state telmisartan concentrations of patients with hypertension were compared among MDR1C3435T genotypes.RESULTS:Among the 61 cases of hypertension patients,the frequencies of C3435T CC,C3435T TT and C3435T CT were 39.34%,11.48% and 49.18

  5. ABCB1, ABCC2, SCN1A, SCN2A, GABRA1 gene polymorphisms and drug resistant epilepsy in the Chinese Han population.

    Science.gov (United States)

    Zhou, Luo; Cao, Yuze; Long, Hongyu; Long, Lili; Xu, Lin; Liu, Zhaoqian; Zhang, Ying; Xiao, Bo

    2015-06-01

    Drug resistance is common in epilepsy despite multiple available medications. Single nucleotide polymorphisms (SNP) may influence drug efficacy in epilepsy. We therefore aimed to clarify the association between polymorphisms of several controversial SNP loci and drug resistance in Chinese Han epilepsy patients from central China. Among all the 391 recruited subjects, 235 and 156 patients were classified into a drug responsive and resistant group, respectively, according to the definition of drug resistance proposed by the International League Against Epilepsy. The candidate SNP loci, including ATP-binding cassette (ABC) subfamily gene ABCB1 rs2032582 and rs1045642; ABC subfamily gene ABCC2 rs717620 and rs2273697; sodium channel subunit gene SCN1A rs3812718, SCN2A rs2304016; γ-amino butyric acid type A (GABAA) receptor subunit subtype gene GABRA1 rs2279020 were genotyped following the Illumina protocols. There were no significant differences in allelic or genotypic frequencies between the drug responsive and resistant patients. The polymorphisms of the above SNP loci may not be associated with drug resistance of epilepsy in the Chinese Han population.

  6. The antinociceptive effect and adverse drug reactions of oxycodone in human experimental pain in relation to genetic variations in the OPRM1 and ABCB1 genes

    DEFF Research Database (Denmark)

    Zwisler, Stine T; Enggaard, Thomas P; Noehr-Jensen, Lene;

    2010-01-01

    -type genotype in the cold pressor test (25% reduction vs. 15%, P = 0.015 in the discomfort rating and 25% reduction vs. 12%, P = 0.007 in the pain time AUC) and less adverse drug reactions. The combined wild-type genotype 3435CC-2677GG was associated with less antinociceptive effect of oxycodone......The aim of this study was to search for a possible association between the variant allele of the single nucleotide polymorphisms A118G in the OPRM1 gene and C3435T and G2677T/A in the ABCB1 gene and altered antinociceptive effect and adverse drug reactions of oxycodone. Thirty-three healthy......% for the wild-type carriers, P = 0.007). C3435T: The carriers of the variant T allele generally had less adverse drug reactions on oxycodone than the carriers of the wild-type genotype. G2677T/A: The carriers of the variant T allele had a better antinociceptive effect of oxycodone than the carriers of the wild...

  7. ABCB1, ABCC2, SCN1A, SCN2A, GABRA1 gene polymorphisms and drug resistant epilepsy in the Chinese Han population.

    Science.gov (United States)

    Zhou, Luo; Cao, Yuze; Long, Hongyu; Long, Lili; Xu, Lin; Liu, Zhaoqian; Zhang, Ying; Xiao, Bo

    2015-06-01

    Drug resistance is common in epilepsy despite multiple available medications. Single nucleotide polymorphisms (SNP) may influence drug efficacy in epilepsy. We therefore aimed to clarify the association between polymorphisms of several controversial SNP loci and drug resistance in Chinese Han epilepsy patients from central China. Among all the 391 recruited subjects, 235 and 156 patients were classified into a drug responsive and resistant group, respectively, according to the definition of drug resistance proposed by the International League Against Epilepsy. The candidate SNP loci, including ATP-binding cassette (ABC) subfamily gene ABCB1 rs2032582 and rs1045642; ABC subfamily gene ABCC2 rs717620 and rs2273697; sodium channel subunit gene SCN1A rs3812718, SCN2A rs2304016; γ-amino butyric acid type A (GABAA) receptor subunit subtype gene GABRA1 rs2279020 were genotyped following the Illumina protocols. There were no significant differences in allelic or genotypic frequencies between the drug responsive and resistant patients. The polymorphisms of the above SNP loci may not be associated with drug resistance of epilepsy in the Chinese Han population. PMID:26189305

  8. A meta-analytic review of ERCC1/MDR1 polymorphism and chemosensitivity to platinum in patients with advanced non-small cell lung cancer

    Institute of Scientific and Technical Information of China (English)

    WEI Hai-bo; HU Jing; SHANG Li-hua; ZHANG Yun-yan; LU Fei-fei; WEI Min; YU Yan

    2012-01-01

    Background Platinum-based regimens are used as standard first-line chemotherapy in non-small cell lung cancer (NSCLC) patients.To study if pharmacogenetic approach may allow a tailored selection of platinum chemotherapy for advanced NSCLC,we performed a meta-analysis to compare chemosensitivity to platinum with different ERCC1 C118T/MDR1 C3435T single-nucleotide polymorphism (SNP).Methods Relevant studies were identified by searching the PubMed,Embase,Cochrane,OVID,Springer,EBSCO and CNKI databases.Inclusion criteria were patients with advanced NSCLC who received platinum-based chemotherapy,an evaluated polymorphism of ERCC/MDR1 and overall response rate.We excluded duplicate publications,letters and review articles.The RevMan 4.2 and STATA 11 package were used to do comprehensive quantitative assessment.Results A total of 11 studies were included in this meta-analysis.For studies evaluating ERCC1 C118T,test for heterogeneity was done (x2=13.41,P=0.1),and the odds ratio (OR) for the wild-type C/C genotype versus the heterozygous C/T and T/T genotypes was 1.50 (95% CI 1.09-2.06,P=-0.01).In four studies evaluating MDR1 polymorphism,test for heterogeneity was also done (x2=3.22,P=0.36),and the OR for the wild-type C/C genotype versus the heterozygous C/T and T/T genotypes was 2.30 (95% CI 1.44-3.68,P=0.0005).Conclusions The results indicated that platinum-based chemotherapy sensitivity was significantly associated with polymorphism of ERCC1 C118T and MDR1 C3435T SNP.In further perspective studies,the ERCC1/MDR1 SNPs might serve as simple and less invasive biomarkers for personalized chemotherapy with platinum-based anticancer drugs.

  9. ABCB1基因多态性与乳腺癌患者化疗所致严重中性粒细胞减少症的相关性研究%Association between ABCB1 Gene Polymorphisms and Chemotherapy-induced Severe Neutropenia in Pa-tients with Breast Cancer

    Institute of Scientific and Technical Information of China (English)

    付正传; 钱芳; 杨旭环; 宫素红; 程曙光; 刘思海

    2016-01-01

    OBJECTIVE:To discuss the association between ABCB1 gene polymorphisms and adriamycin and cyclophospha-mide(AC)combined with chemotherapy-induced severe neutropenia in patients with breast cancer. METHODS:218 breast cancer patients receiving AC combined with chemotherapy were selected from our hospital during 2012-2015;PCR-RFLP was used to de-tect polymorphisms of ABCB1 2677G>T/A and 3435C>T. The associated between different age,BMI,clinical stages genotypes, etc and AC combined with chemotherapy-induced severe neutropenia were investigated,and risk factors of neutropenia were ana-lyzed by multivariate logistic regression. RESULTS:Among 218 breast cancer patients,170 patients suffered from severe neutrope-nia,accounting for 78.0%. Among ABCB1 2677G>T/A polymorphisms,distribution frequency of GT or GA genotype,TT,TA or AA genotype,GG genotype in severe neutropenia were 80.6%,86.2% and 60.0%,with statistical significance (PT polymorphisms,distribution frequency of TT,CT and CC genotype in severe neutropenia were 86.4%, 78.4% and 72.7%,there was no statistical significance(P>0.05). AST and ABCB1 2677G>T/A polymorphisms were correlated with severe neutropenia (PT/A polymorphism was a strong predictor of neutropenia [OR=3.875, 95%CI(1.555,9.922),P=0.008]. CONCLUSIONS:ABCB1 2677>T/A polymorphisms may be aggravate AC combined with che-motherapy-induced neutropenia in patients with breast cancer.%目的:探讨乳腺癌患者三磷酸腺苷结合盒转运子B亚家族成员1(ABCB1)基因多态性与多柔比星和环磷酰胺(AC)联合化疗所致严重中性粒细胞减少症的相关性。方法:选择我院2012-2015年接受AC联合化疗的乳腺癌患者218例,采用聚合酶链-限制性片段长度多态性分析法进行ABCB12677G>T/A、3435C>T基因多态性检测,考察患者不同年龄、体质量指数、临床分期、基因型等各因素与AC联合化疗所致严重中性粒细胞减少症的相关性,并采用多元逻辑回归分析

  10. Multiplicity of acquired cross-resistance in paclitaxel-resistant cancer cells is associated with feedback control of TUBB3 via FOXO3a-mediated ABCB1 regulation

    Science.gov (United States)

    Aldonza, Mark Borris D.; Hong, Ji-Young; Alinsug, Malona V.; Song, Jayoung; Lee, Sang Kook

    2016-01-01

    Acquired drug resistance is a primary obstacle for effective cancer therapy. The correlation of point mutations in class III β-tubulin (TUBB3) and the prominent overexpression of ATP-binding cassette P-glycoprotein (ABCB1), a multidrug resistance gene, have been protruding mechanisms of resistance to microtubule disruptors such as paclitaxel (PTX) for many cancers. However, the precise underlying mechanism of the rapid onset of cross-resistance to an array of structurally and functionally unrelated drugs in PTX-resistant cancers has been poorly understood. We determined that our established PTX-resistant cancer cells display ABCB1/ABCC1-associated cross-resistance to chemically different drugs such as 5-fluorouracil, docetaxel, and cisplatin. We found that feedback activation of TUBB3 can be triggered through the FOXO3a-dependent regulation of ABCB1, which resulted in the accentuation of induced PTX resistance and encouraged multiplicity in acquired cross-resistance. FOXO3a-directed regulation of P-glycoprotein (P-gp) function suggests that control of ABCB1 involves methylation-dependent activation. Consistently, transcriptional overexpression or downregulation of FOXO3a directs inhibitor-controlled protease-degradation of TUBB3. The functional PI3K/Akt signaling is tightly responsive to FOXO3a activation alongside doxorubicin treatment, which directs FOXO3a arginine hypermethylation. In addition, we found that secretome factors from PTX-resistant cancer cells with acquired cross-resistance support a P-gp-dependent association in multidrug resistance (MDR) development, which assisted the FOXO3a-mediated control of TUBB3 feedback. The direct silencing of TUBB3 reverses induced multiple cross-resistance, reduces drug-resistant tumor mass, and suppresses the impaired microtubule stability status of PTX-resistant cells with transient cross-resistance. These findings highlight the control of the TUBB3 response to ABCB1 genetic suppressors as a mechanism to reverse the

  11. The Alterations in the Expression and Function of P-Glycoprotein in Vitamin A-Deficient Rats as well as the Effect of Drug Disposition in Vivo

    Directory of Open Access Journals (Sweden)

    Yubang Wang

    2015-12-01

    Full Text Available This study was aimed to investigate whether vitamin A deficiency could alter P-GP expression and function in tissues of rats and whether such effects affected the drug distribution in vivo of vitamin A-deficient rats. We induced vitamin A-deficient rats by giving them a vitamin A-free diet for 12 weeks. Then, Abcb1/P-GP expression was evaluated by qRT-PCR and Western blot. qRT-PCR analysis revealed that Abcb1a mRNA levels were increased in hippocampus and liver. In kidney, it only showed an upward trend. Abcb1b mRNA levels were increased in hippocampus, but decreased in cerebral cortex, liver and kidney. Western blot results were in good accordance with the alterations of Abcb1b mRNA levels. P-GP function was investigated through tissue distribution and body fluid excretion of rhodamine 123 (Rho123, and the results proclaimed that P-GP activities were also in good accordance with P-GP expression in cerebral cortex, liver and kidney. The change of drug distribution was also investigated through the tissue distribution of vincristine, and the results showed a significantly upward trend in all indicated tissues of vitamin A-deficient rats. In conclusion, vitamin A deficiency may alter Abcb1/P-GP expression and function in rat tissues, and the alterations may increase drug activity/toxicity through the increase of tissue accumulation.

  12. The Alterations in the Expression and Function of P-Glycoprotein in Vitamin A-Deficient Rats as well as the Effect of Drug Disposition in Vivo.

    Science.gov (United States)

    Wang, Yubang; Qin, Heng; Zhang, Chengxiang; Huan, Fei; Yan, Ting; Zhang, Lulu

    2015-12-29

    This study was aimed to investigate whether vitamin A deficiency could alter P-GP expression and function in tissues of rats and whether such effects affected the drug distribution in vivo of vitamin A-deficient rats. We induced vitamin A-deficient rats by giving them a vitamin A-free diet for 12 weeks. Then, Abcb1/P-GP expression was evaluated by qRT-PCR and Western blot. qRT-PCR analysis revealed that Abcb1a mRNA levels were increased in hippocampus and liver. In kidney, it only showed an upward trend. Abcb1b mRNA levels were increased in hippocampus, but decreased in cerebral cortex, liver and kidney. Western blot results were in good accordance with the alterations of Abcb1b mRNA levels. P-GP function was investigated through tissue distribution and body fluid excretion of rhodamine 123 (Rho123), and the results proclaimed that P-GP activities were also in good accordance with P-GP expression in cerebral cortex, liver and kidney. The change of drug distribution was also investigated through the tissue distribution of vincristine, and the results showed a significantly upward trend in all indicated tissues of vitamin A-deficient rats. In conclusion, vitamin A deficiency may alter Abcb1/P-GP expression and function in rat tissues, and the alterations may increase drug activity/toxicity through the increase of tissue accumulation.

  13. 终末期肾脏病患者MDR1基因多态性和二氢吡啶类钙拮抗剂诱导牙龈增生的关系%Polymorphism in MDR1 gene may affect gingival hyperplasia induced by calcium channel blockers in end-stage renal disease patients

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    目的 探讨终末期肾脏病(endstage renal disease,ESRD)患者MDR1基因多态性和二氢吡啶类钙拮抗剂(calcium channel blockers,CCB)诱导牙龈增生的关系. 方法 入选183例ESRD高血压患者,根据所使用的CCB分为3组,同时检测MDR1C3435T基因多态性. 结果 共有152例患者最终纳入分析,84例发生牙龈增生,其中硝苯地平54例、非洛地平15例和氨氯地平15例,各组患者牙龈增生的发生率无显著性差异(X2=4.968,P=0.083);且MDR1C3435T基因频率分布符合Hardy-Weinberg平衡分布(CC=28.3%,CT=50.7%,TT=21.0%;X2=0.032,P=0.985);同时各基因型牙龈增生比例无显著差异(X2=3.690,P=0.158),3个基因型牙龈增生严重程度无显著差异(F=0.406,P=0.667). 结论 MDR1C3435T基因多态性可能与ESRD高血压患者使用CCB诱导牙龈增生无显著相关,尚需要在更大样本中进一步检验.

  14. mdr1启动子调控CD::UPP基因对紫杉醇耐药卵巢癌细胞的杀伤作用%Cell-killing effects of adenovirus-mediated transfer of CD :: UPP gene directed by mdr1 promoter on Taxol-resistant ovarian cancer cells

    Institute of Scientific and Technical Information of China (English)

    卢实; 蔡俐琼; 王晓翊; 王泽华

    2007-01-01

    目的:探讨腺病毒介导的mdr1启动子调控胞嘧啶脱氨酶::尿嘧啶磷酸核糖转移酶(CD::UPP)融合基因联合5-氟胞嘧啶(5-FC)对紫杉醇耐药卵巢癌细胞的特异性杀伤作用.方法:扩增、纯化含有mdr1-CD::UPP基因的重组腺病毒,转染人卵巢癌紫杉醇耐药细胞株A2780/Taxol和亲本细胞株A2780,RT-PCR检测mdr1和CD::UPP基因的表达水平;之后加入5-FC,MTT法检测细胞抑制情况及旁观者效应,并观察腺病毒转染后裸鼠移植瘤的生长情况.结果:mdr1和CD::UPP基因在A2780/Taxol细胞中可稳定表达,转染后A2780/Taxol组的细胞生长明显低于A2780组;转基因的A2780/Taxol细胞联合5-FC后可通过旁观者效应杀伤周围未转基因的耐药细胞;耐药组移植瘤生长明显受到抑制,肿瘤体积为(569.10±187.93)mm3,对照组肿瘤体积为(2 111.98±230.82)mm3,差异有统计学意义(P<0.01).结论:mdr1启动子可调控CD::UPP基因特异性表达并特异性杀伤紫杉醇耐药卵巢癌细胞.

  15. 卵巢癌组织中MDR1(P—gp)、GST-π基因的表达及其临床意义

    Institute of Scientific and Technical Information of China (English)

    李家梅; 盖晓东; 王绍娟; 吴国新

    2006-01-01

    目的:探讨MDR1、GST-π的表达及其临床意义。方法:采用免疫组化SP法检测47例卵巢癌组织中MDR1(P—gp)、GST-π的表达情况。结果:①MDRI(P—gp)、GST—π在肿瘤大小、肿瘤来源方面差异无显著性。②MDRI(P—gp)、GST-π的阳阴性表达与临床分期之间差异有显著性。③复发患者的肿瘤组织中MDRI(P—gp)、GST—π阳性表达率明显高于初治组。讨论:①MDRI(P—gp)、GST-π的表达与肿瘤大小、病理类型无明显相关,但在临床分期,初发与复发之间有明显相关性。②复发患者的肿瘤组织中MDRI(P—gp)、GST-π表达阳性率明显高于初治组,提示卵巢癌对化疗药物特剐是铂类药物可能有获得性耐药,与肿瘤组织在接受化疗后出现基因激活有关。

  16. Association study of C3435T genetic polymorphism of MDR1 gene with efficacy of pailperidone extended-release tablets%精神分裂症患者MDR1C3435T基因多态性与帕利哌酮疗效的相关性

    Institute of Scientific and Technical Information of China (English)

    乔兴菊; 贾福军; 周志凌; 朱杰宁; 谢永标

    2012-01-01

    Objective:To investigate the genotypes of C3435T of MDR1 gene in peripheral blood of pa tients with schizophrenia, and analyze the association between C3435T genetic polymorphism of MDR1 gene with efficacy of pailperidone extended-release tablets. Method:68 schizophrenia patients who took pailperidone, extended-release tablets were included in the study. They were assessed with positive and negative symptoms scales (PANSS) and the personal and social performance scale (PSP).The patients were divided into respon sive group and unresponsive group by the score of PANSS reduction rate. C3435T polymorphism was analyzed by the polymerase chain reaction restriction fragment length polymorphism ( PCR-RFLP) method. The results were analyzed by Chi-square test. Results: There was marked difference between the score of PANSS and PSP be fore and after 6 weeks treatment for Pailperidone extended-release tablets. The differences of genotype in the re sponsive group and unresponsive group were not significant ( P > 0.05 ). Conclusion: Pailperidone extended release tablet was found to be effective in improving psychotic and personal and social performance. The relation ship was not found between C3435T genetic polymorphism of MDR1 gene and the efficacy of paliperidone ER in patients with schizophrenia.%目的:研究精神分裂症患者MDR1C3435T基因多态性与帕利哌酮缓释片疗效的相关性.方法:收集服用非典型抗精神病药物帕利哌酮缓释片患者68例,采用阳性和阴性症状量表(PANSS)评定疗效,个人与社会功能量表(PSP)评定社会功能,根据PANSS减分率(≥50%为有效)分为有效组和无效组.采用聚合酶链反应-限制性片段长度多态性分析(PCR-RFLP)技术检测其MDR1 C3435T位点的基因型.将有效组和无效组的基因型进行卡方检验.结果:治疗前后PANSS及PSP量表评分比较差异有统计学意义(P <0.001),有效组与无效组基因型差异无统计学差别(P>0.05) 结论:帕利哌

  17. Polymorphism of multidrug-resistance gene in childhood refractory epilepsy%儿童难治性癫(癎)MDR1基因多态性研究

    Institute of Scientific and Technical Information of China (English)

    高萱; 周水珍; 郭倩; 孙道开

    2009-01-01

    目的 探讨儿童难治性癫(癎)的诊断问题及汉族儿童难治性癫(癎)MDR1基因单核苷酸多态性C3435T与癫(癎)耐药的相关性.方法 采用回顾性及前瞻性分析方法对400例癫(癎)儿童进行随访,自定儿童难治性癫(癎)(RE)诊断标准,分析其中难治性癫(癎)类型、用药种类、用药时间、药物调整时间及疗效;根据对抗癫(癎)药物的反应将儿童癫(癎)患者分为难治组、控制组,健康儿童作为正常对照组;提取132例患儿(难治组70例,控制组62例)及健康62例儿童外周血DNA,以PCR扩增,DNA直接测序法检测MDR基因C3435T的单核苷酸多态性;应用病例对照研究,分析基因多态性在癫(癎)患者中的分布特点及其与癫(癎)耐药的相关性.结果 400例癫(癎)患儿中难治性癫(癎)83例(20.8%),65例(78.3%)在6个月内完成至少2种药物调整,目前仍有42例(50.6%)同时使用3种及以上药物治疗,其中6例(7.2%)同时使用4种抗癫(癎)药物.83例难治性癫(癎)患者用药有效40例(48.2%),显效6例(7.2%);无效37例(44.6%),其中25例(67.6%)有不同程度的减轻.70例耐药组患儿与62例控制组患儿及62例健康对照相比较,各组CC基因型、CT基因型、TT基因型及等位基因频率差异均无统计学意义.多因素Logistic回归分析显示,MDR1C3435T各基因型与癫(癎)耐药无相关性.结论 儿童癫(癎)患儿正规治疗6个月后仍不能控制发作者认为其为难治性癫(癎)(平均至少1次/月,>2种药物无效),多种AEDs治疗仍有其必要性,未发现汉族儿童C3435T基因多态性与癫(癎)耐药的相关性.%Objective To discuss the diagnosis of refractory epilepsy (RE) in children, and to study the association of the single nucleotide polymorphisms (SNPs) of muhidrug-resistance gene (MDR1) C3435T with pharmaco- resistant epilepsy. Methods Four hundred children with epilepsy were retrospectively or prospectively identified from multiple sources in our hospital in

  18. Expression of mdr isoforms in mice during estrous cycle and under hormone stimulation

    OpenAIRE

    Marion Schiengold; Lavínia Schwantes; Ribeiro, Maria F; Nívia Lothhammer; Gonzalez, Tatiana P.; Jose Artur Bogo Chies; Nardi, Nance B

    2006-01-01

    The multidrug resistance (MDR) phenotype is associated with the expression of P-glycoprotein (Pgp), coded by the multigenic mdr family. Mice present the isoforms mdr1 and mdr3, which are responsible for multidrug resistance, and mdr2, that is involved in the transport of phospholipids. mdr1 expression has more recently been associated also with the secretion of steroid hormones. This work presents an RT-PCR analysis of the expression of mdr isoforms, in several organs of mice during different...

  19. P-glycoprotein in sheep liver and small intestine: gene expression and transport efflux activity.

    Science.gov (United States)

    Ballent, M; Wilkens, M R; Maté, L; Muscher, A S; Virkel, G; Sallovitz, J; Schröder, B; Lanusse, C; Lifschitz, A

    2013-12-01

    The role of the transporter P-glycoprotein (P-gp) in the disposition kinetics of different drugs therapeutically used in veterinary medicine has been demonstrated. Considering the anatomo-physiological features of the ruminant species, the constitutive expression of P-gp (ABCB1) along the sheep gastrointestinal tract was studied. Additionally, the effect of repeated dexamethasone (DEX) administrations on the ABCB1 gene expression in the liver and small intestine was also assessed. The ABCB1 mRNA expression was determined by real-time quantitative PCR. P-gp activity was evaluated in diffusion chambers to determine the efflux of rhodamine 123 (Rho 123) in the ileum from experimental sheep. The constitutive ABCB1 expression was 65-fold higher in the liver than in the intestine (ileum). The highest ABCB1 mRNA expression along the small intestine was observed in the ileum (between 6- and 120-fold higher). The treatment with DEX did not elicit a significant effect on the P-gp gene expression levels in any of the investigated gastrointestinal tissues. Consistently, no significant differences were observed in the intestinal secretion of Rho 123, between untreated control (Peff S-M = 3.99 × 10(-6)  ± 2.07 × 10(-6) ) and DEX-treated animals (Peff S-M = 6.00 × 10(-6)  ± 2.5 × 10(-6) ). The understanding of the efflux transporters expression and activity along the digestive tract may help to elucidate clinical implications emerging from drug interactions in livestock.

  20. Bcrp1;Mdr1a/b;Mrp2 Combination Knockout Mice: Altered Disposition of the Dietary Carcinogen PhIP (2-Amino-1-Methyl-6-Phenylimidazo[4,5-b]Pyridine) and Its Genotoxic Metabolites

    NARCIS (Netherlands)

    Vlaming, M.L.H.; Teunissen, S.F.; Steeg, E. van de; Esch, A. van; Wagenaar, E.; Brunsveld, L.; Greef, T.F.A. de; Rosing, H.; Schellens, J.H.M.; Beijnen, J.H.; Schinkel, A.H.

    2014-01-01

    The multidrug transporters breast cancer resistance protein (BCRP), multidrug-resistance protein 1 (MDR1), and multidrugresistance–associated protein (MRP) 2 and 3 eliminate toxic compounds from tissues and the body and affect the pharmacokinetics of many drugs and other potentially toxic compounds.

  1. Heterologously expressed bacterial and human multidrug resistance proteins confer cadmium resistance to Escherichia coli

    OpenAIRE

    Achard-Joris, M; van Saparoea, HBV; Driessen, AJM; Bourdineaud, JP; Bourdineaud, Jean-Paul

    2005-01-01

    The human MDR1 gene is induced by cadmium exposure although no resistance to this metal is observed in human cells overexpressing hMDR1. To access the role of MDR proteins in cadmium resistance, human MDR1, Lactococcus lactis lmrA, and Oenococcus oeni omrA were expressed in an Escherichia coli tolC mutant strain which proved to be hypersensitive to cadmium. Both the human and bacterial MDR genes conferred cadmium resistance to E. coli up to 0.4 mM concentration. Protection was abolished by 10...

  2. Fitting the elementary rate constants of the P-gp transporter network in the hMDR1-MDCK confluent cell monolayer using a particle swarm algorithm.

    Directory of Open Access Journals (Sweden)

    Deep Agnani

    Full Text Available P-glycoprotein, a human multidrug resistance transporter, has been extensively studied due to its importance to human health and disease. In order to understand transport kinetics via P-gp, confluent cell monolayers overexpressing P-gp are widely used. The purpose of this study is to obtain the mass action elementary rate constants for P-gp's transport and to functionally characterize members of P-gp's network, i.e., other transporters that transport P-gp substrates in hMDR1-MDCKII confluent cell monolayers and are essential to the net substrate flux. Transport of a range of concentrations of amprenavir, loperamide, quinidine and digoxin across the confluent monolayer of cells was measured in both directions, apical to basolateral and basolateral to apical. We developed a global optimization algorithm using the Particle Swarm method that can simultaneously fit all datasets to yield accurate and exhaustive fits of these elementary rate constants. The statistical sensitivity of the fitted values was determined by using 24 identical replicate fits, yielding simple averages and standard deviations for all of the kinetic parameters, including the efflux active P-gp surface density. Digoxin required additional basolateral and apical transporters, while loperamide required just a basolateral tranporter. The data were better fit by assuming bidirectional transporters, rather than active importers, suggesting that they are not MRP or active OATP transporters. The P-gp efflux rate constants for quinidine and digoxin were about 3-fold smaller than reported ATP hydrolysis rate constants from P-gp proteoliposomes. This suggests a roughly 3∶1 stoichiometry between ATP hydrolysis and P-gp transport for these two drugs. The fitted values of the elementary rate constants for these P-gp substrates support the hypotheses that the selective pressures on P-gp are to maintain a broad substrate range and to keep xenobiotics out of the cytosol, but not out of the

  3. Reversal of typical multidrug resistance by cyclosporin and its non-immunosuppressive analogue SDZ PSC 833 in Chinese hamster ovary cells expressing the mdr1 phenotype

    NARCIS (Netherlands)

    P.A.W. Boekhorst; J. van Kapel (Jan); M. Schoester (Martijn); P. Sonneveld (Pieter)

    1992-01-01

    markdownabstractSummary The new non-immunosuppressive cyclosporin derivative SDZ PSC 833 (PSC) is a potent agent used to overcome typical multidrug resistance (MDR) associated with overexpression of themdr1 gene encoding for a P-170 glycoprotein. In the present study, the efficacy of PSC as compar

  4. mdr1启动子调控双自杀基因对卵巢癌SKOV3耐药细胞的靶向杀伤作用%The selective killing effects of adenovirus mediated double suicide gene system controlled by MDR1 promoter on SKOV3/Taxol ovarian cancer cells

    Institute of Scientific and Technical Information of China (English)

    卢实; 王晓翊; 肖蓝; 蔡俐琼; 王泽华

    2007-01-01

    目的 观察多药耐药基因1(mdr1)启动子调控腺病毒介导的胞嘧啶脱氨酶∷尿嘧啶磷酸核糖转移酶(CD∷UPP)融合基因系统对人卵巢癌紫杉醇耐药细胞的靶向杀伤作用.方法 2004年10月至2005年5月于华中科技大学附属协和医院,将重组腺病毒(Admdr1-CD∷UPP)转染卵巢癌紫杉醇耐药细胞(SKOV3/Taxol)及非耐药细胞(SKOV3),荧光显微镜下观察转染效率,用逆转录-聚合酶链反应(RT-PCR)检测目的基因CD∷UPP的表达,并给予不同浓度的5-氟胞嘧啶(5-FC),用四甲基偶氮唑蓝(MTT)法检测二组的细胞存活率及旁观者效应.结果 重组腺病毒对SKOV3/Taxol的转染率随腺病毒滴度的递增而增加,感染复数(MOI)为50时,感染率约100%;CD∷UPP基因仅在SKOV3/Taxol中稳定表达;5-FC对耐药细胞转基因组的杀伤作用显著高于非耐药细胞转基因组,前者表现出明显的旁观者效应.结论 mdr1启动子调控的CD∷UPP融合自杀基因系统对人卵巢癌紫杉醇耐药细胞有靶向杀伤作用.

  5. 浙南地区女性人群CYP2D6及MDR1基因多态性对曲马多镇痛效果的影响

    Institute of Scientific and Technical Information of China (English)

    马光泛; 陈千煌

    2013-01-01

      目的探讨CYP2D6*10等位基因及MDR1 C3435T基因多态性对浙南地区女性人群术后曲马多镇痛效果的影响.方法收集行子宫肌瘤剥除手术患者194例,手术结束前30 min肌肉注射曲马多,采用患者自控镇痛(PCA)模式进行术后镇痛.抽取外周血,采用聚合酶链反应-限制性条带长度多态性方法(PCR-RFLP),分析患者CYP2D6*10等位基因及MDR1 C3435T基因多态性,比较不同基因型患者之间曲马多的累积量,记录镇痛起效时间、持续时间、VAS及不良反应.结果 CYP2D6*10等位基因频率为52.84%,术后2、6、12h曲马多累积量及术后2、6hVAS的比较,m/m型明显高于w/w型和m/w型,差异有统计学意义(P0.05).结论在浙南地区女性人群中,CYP2D6*10等位基因对曲马多镇痛效果有显著影响,MDR1 C3435T等位基因对曲马多镇痛效果无显著影响.%Objective To investigate the association of CYP2D6*10 and MDR1 C3435T polymorphisms with analgesic ef-ficacy of tramadol in woman patients of Southern Zhejiang province. Methods One hundred and ninety four patients with hys-termyoma undergoing uterine myomatectomy from August 2010 to March 2012. Patients were given with loading dose of tramadol intramuscularly 30 minutes before the ending of surgery and received the postoperative patient-control ed analgesia (PCA). Samples of peripheral blood were col ected for DNA isolation. Polymorphisms of CYP2D6*10 and MDR1 C3435T were detected with PCR-RFLP analysis. The differences of tramadol consumption in the genotype groups were monitored and the starting time and duration of analgesia, VAS scores and adverse reaction were observed. Results The al elic frequency of CYP2D6 was 52.84%. The tramadol consumption at 2、6h and 12h after surgery and VAS at 2h and 6h after surgery in m/m type (n=50) were higher than those in w/w (n=39) and m/w (n=105) type (P<0.05). Variant al eles C3435T in MDR1 gene was seen in frequency of 38.14%. There were no significant

  6. RSK1 protects P-glycoprotein/ABCB1 against ubiquitin–proteasomal degradation by downregulating the ubiquitin-conjugating enzyme E2 R1

    Science.gov (United States)

    Katayama, Kazuhiro; Fujiwara, Chiaki; Noguchi, Kohji; Sugimoto, Yoshikazu

    2016-01-01

    P-glycoprotein (P-gp) is a critical determinant of multidrug resistance in cancer. We previously reported that MAPK inhibition downregulates P-gp expression and that P-gp undergoes ubiquitin–proteasomal degradation regulated by UBE2R1 and SCFFbx15. Here, we investigated the crosstalk between MAPK inhibition and the ubiquitin–proteasomal degradation of P-gp. Proteasome inhibitors or knockdown of FBXO15 and/or UBE2R1 cancelled MEK inhibitor-induced P-gp downregulation. RSK1 phosphorylated Thr162 on UBE2R1 but did not phosphorylate FBXO15. MEK and RSK inhibitors increased UBE2R1-WT but not UBE2R1-T162D and -T162A expression. UBE2R1-T162D showed higher self-ubiquitination and destabilisation than UBE2R1-WT and -T162A. Unlike UBE2R1-WT and -T162A, UBE2R1-T162D did not induce P-gp ubiquitination. UBE2R1-WT or -T162A downregulated P-gp expression and upregulated rhodamine 123 level and sensitivity to vincristine and doxorubicin. However, UBE2R1-T162D did not confer any change in P-gp expression, rhodamine 123 accumulation and sensitivity to the drugs. These results suggest that RSK1 protects P-gp against ubiquitination by reducing UBE2R1 stability. PMID:27786305

  7. Nuclear multidrug-resistance related protein 1 contributes to multidrug-resistance of mucoepidermoid carcinoma mainly via regulating multidrug-resistance protein 1: a human mucoepidermoid carcinoma cells model and Spearman's rank correlation analysis.

    Directory of Open Access Journals (Sweden)

    Bolei Cai

    Full Text Available BACKGROUND: Multidrug resistance-related protein 1 (MRP1/ABCC1 and multidrug resistance protein 1 (MDR1/P-glycoprotein/ABCB1 are both membrane-bound drug transporters. In contrast to MDR1, MRP1 also transports glutathione (GSH and drugs conjugated to GSH. Due to its extraordinary transport properties, MRP1/ABCC1 contributes to several physiological functions and pathophysiological incidents. We previously found that nuclear translocation of MRP1 contributes to multidrug-resistance (MDR of mucoepidermoid carcinoma (MEC. The present study investigated how MRP1 contributes to MDR in the nuclei of MEC cells. METHODS: Western blot and RT-PCR was carried out to investigate the change of multidrug-resistance protein 1 (MDR1 in MC3/5FU cells after MRP1 was downregulated through RNA interference (RNAi. Immunohistochemistry (IHC staining of 127 cases of MEC tissues was scored with the expression index (EI. The EI of MDR1 and MRP1 (or nuclear MRP1 was analyzed with Spearman's rank correlation analysis. Using multiple tumor tissue assays, the location of MRP1 in other tissues was checked by HIC. Luciferase reporter assays of MDR1 promoter was carried out to check the connection between MRP1 and MDR1 promoter. RESULTS: MRP1 downregulation led to a decreased MDR1 expression in MC3/5FU cells which was caused by decreased activity of MDR1 promoter. IHC study of 127 cases of MEC tissues demonstrated a strong positive correlation between nuclear MRP1 expression and MDR1 expression. Furthermore, IHC study of multiple tumor tissue array sections showed that although nuclear MRP1 widely existed in MEC tissues, it was not found in normal tissues or other tumor tissues. CONCLUSIONS: Our findings indicate that nuclear MRP1 contributes to MDR mainly through regulating MDR1 expression in MEC. And the unique location of MRP1 made it an available target in identifying MEC from other tumors.

  8. Functional expression of murine multidrug resistance in Xenopus laevis oocytes

    Energy Technology Data Exchange (ETDEWEB)

    Castillo, G.; Vera, J.C.; Rosen, O.M. (Memorial Sloan-Kettering Cancer Research Center, New York, NY (USA)); Yang, Chiaping Huang; Horwitz, S.B. (Albert Einstein College of Medicine, Bronx, NY (USA))

    1990-06-01

    The development of multidrug resistance (MDR) is associated with the overproduction of a plasma membrane glycoprotein, P glycoprotein. Here the authors report the functional expression of a member of the murine MDR family of proteins and show that Xenopus oocytes injected with RNA encoding the mouse mdr1b P glycoprotein develop a MDR-like phenotype. Immunological analysis indicated that oocytes injected with the mdr1b RNA synthesized a protein with the size and immunological characteristics of the mouse mdr1b P glycoprotein. These oocytes exhibited a decreased accumulation of ({sup 3}H)vinblastine and showed an increased capacity to extrude the drug compared to control oocytes not expressing the P glycoprotein. In addition, competition experiments indicated that verapamil, vincristine, daunomycin, and quinidine, but not colchicine, can overcome the rapid drug efflux conferred by the expression of the mouse P glycoprotein.

  9. Expression of mdr isoforms in mice during estrous cycle and under hormone stimulation

    Directory of Open Access Journals (Sweden)

    Marion Schiengold

    2006-01-01

    Full Text Available The multidrug resistance (MDR phenotype is associated with the expression of P-glycoprotein (Pgp, coded by the multigenic mdr family. Mice present the isoforms mdr1 and mdr3, which are responsible for multidrug resistance, and mdr2, that is involved in the transport of phospholipids. mdr1 expression has more recently been associated also with the secretion of steroid hormones. This work presents an RT-PCR analysis of the expression of mdr isoforms, in several organs of mice during different phases of the estrous cycle. Additionally, females were ovariectomized, submitted to different hormone treatments, and their uterus was analyzed for the expression of mdr isoforms. The results show that in the adrenal gland and ovaries mdr1 is the main isoform during proestrus, and that progesterone or a combination of progesterone and estrogen induce the expression of all mdr isoforms in the uterus of ovariectomized females. We suggest that the functions of mdr1 and mdr3 are overlapping, that mdr3 may be the more efficient isoform in the detoxification function, and that mdr1 may be more closely related to the secretion of steroid hormones.

  10. Expression of multidrug resistance 1 gene and C3435T genetic polymorphism in peripheral blood of patients with intractable epilepsy

    Institute of Scientific and Technical Information of China (English)

    Xueping Zheng; Lan Tan; Jinghui Song; Yan Wang; Yanping Sun

    2008-01-01

    BACKGROUND: Increased expression of multidrug resistance 1 (MDR1) mRNA in peripheral blood of patients with intractable epilepsy is not due to epilepsy drugs, but epilepsy behavior. Monitoring MDR1 expression in peripheral blood is a target for MDR1 gene evaluation. OBJECTIVE: To investigate the influence of antiepileptic drugs and seizures on MDR expression in intractable epilepsy, and to analyze the genetic polymnrphisms of C3435T in the MDR1 gene. DESIGN, TIME AND SETTING: Factorial designs and comparative observations at the experimental center of the Affiliated Hospital of Qingdao Medical College, Qingdao University between October 2003 and October 2004. PARTICIPANTS: A total of 120 subjects were recruited from the epilepsy clinical department of the Affiliated Hospital of Qingdao Medical College. Four groups (n = 30) were classified according to statistical factorial design: intractable epilepsy, treatment response, no treatment, and normal control groups. METHODS: One-step semi-quantitative reverse-transcription polymerase chain reaction technology was used to test expressions of the MDR1 gene in 120 subjects. C3435T polymorphisms in intractable epilepsy group and normal control groups were analyzed by polymerase chain reaction-restriction fragment length polymorphism. MAIN OUTCOME MEASURES: Expression of MDR1 mRNA in the four groups, and C3435T genetic polymorphisms in intractable epilepsy and normal control groups. RESULTS: MDR1 gene expression was increased in the intractable epilepsy group, due to the factor seizures, but not the antiepileptic drugs. However, the interaction between the two factors was not statistically significant. Of the 30 subjects in the intractable epilepsy group, the following genotypes were exhibited: 3 (10%) C/C genotype, 9 (30%) C/T genotype, and 18 (60%) T/T genotype at the site of C3435T, while 4 (13%), 10 (33%), and 16 (53%) subjects were determined to express these genotypes in the normal control group, respectively. C and T

  11. Multidrug resistance 1 gene expression and AgNOR in childhood acute leukemias

    OpenAIRE

    Balamurugan, S.; Sugapriya, D.; Shanthi, P.; Thilaka, V.; Venkatadesilalu, S.; Pushpa, V.; Madhavan, M.

    2007-01-01

    The multidrug resistance 1 (MDR1) gene product, P-glycoprotein (Pgp/p170) is a membrane protein, which acts as an ATP dependant efflux pump that expels a wide variety of organic compounds including chemotherapeutic agents from the cell. Pgp over expression has been demonstrated to be linked with poor treatment outcome and poor prognosis in a number of malignant tumors. AgNORs is a simple, reliable and inexpensive method of evaluating the proliferative activity of a tumor. We have studied MDR1...

  12. Artemether resistance in vitro is linked to mutations in PfATP6 that also interact with mutations in PfMDR1 in travellers returning with Plasmodium falciparum infections.

    KAUST Repository

    Pillai, Dylan R

    2012-04-27

    BACKGROUND: Monitoring resistance phenotypes for Plasmodium falciparum, using in vitro growth assays, and relating findings to parasite genotype has proved particularly challenging for the study of resistance to artemisinins. METHODS: Plasmodium falciparum isolates cultured from 28 returning travellers diagnosed with malaria were assessed for sensitivity to artemisinin, artemether, dihydroartemisinin and artesunate and findings related to mutations in pfatp6 and pfmdr1. RESULTS: Resistance to artemether in vitro was significantly associated with a pfatp6 haplotype encoding two amino acid substitutions (pfatp6 A623E and S769N; (mean IC50 (95% CI) values of 8.2 (5.7 - 10.7) for A623/S769 versus 623E/769 N 13.5 (9.8 - 17.3) nM with a mean increase of 65%; p = 0.012). Increased copy number of pfmdr1 was not itself associated with increased IC50 values for artemether, but when interactions between the pfatp6 haplotype and increased copy number of pfmdr1 were examined together, a highly significant association was noted with IC50 values for artemether (mean IC50 (95% CI) values of 8.7 (5.9 - 11.6) versus 16.3 (10.7 - 21.8) nM with a mean increase of 87%; p = 0.0068). Previously described SNPs in pfmdr1 are also associated with differences in sensitivity to some artemisinins. CONCLUSIONS: These findings were further explored in molecular modelling experiments that suggest mutations in pfatp6 are unlikely to affect differential binding of artemisinins at their proposed site, whereas there may be differences in such binding associated with mutations in pfmdr1. Implications for a hypothesis that artemisinin resistance may be exacerbated by interactions between PfATP6 and PfMDR1 and for epidemiological studies to monitor emerging resistance are discussed.

  13. Artemether resistance in vitro is linked to mutations in PfATP6 that also interact with mutations in PfMDR1 in travellers returning with Plasmodium falciparum infections

    Directory of Open Access Journals (Sweden)

    Pillai Dylan R

    2012-04-01

    Full Text Available Abstract Background Monitoring resistance phenotypes for Plasmodium falciparum, using in vitro growth assays, and relating findings to parasite genotype has proved particularly challenging for the study of resistance to artemisinins. Methods Plasmodium falciparum isolates cultured from 28 returning travellers diagnosed with malaria were assessed for sensitivity to artemisinin, artemether, dihydroartemisinin and artesunate and findings related to mutations in pfatp6 and pfmdr1. Results Resistance to artemether in vitro was significantly associated with a pfatp6 haplotype encoding two amino acid substitutions (pfatp6 A623E and S769N; (mean IC50 (95% CI values of 8.2 (5.7 – 10.7 for A623/S769 versus 623E/769 N 13.5 (9.8 – 17.3 nM with a mean increase of 65%; p = 0.012. Increased copy number of pfmdr1 was not itself associated with increased IC50 values for artemether, but when interactions between the pfatp6 haplotype and increased copy number of pfmdr1 were examined together, a highly significant association was noted with IC50 values for artemether (mean IC50 (95% CI values of 8.7 (5.9 – 11.6 versus 16.3 (10.7 – 21.8 nM with a mean increase of 87%; p = 0.0068. Previously described SNPs in pfmdr1 are also associated with differences in sensitivity to some artemisinins. Conclusions These findings were further explored in molecular modelling experiments that suggest mutations in pfatp6 are unlikely to affect differential binding of artemisinins at their proposed site, whereas there may be differences in such binding associated with mutations in pfmdr1. Implications for a hypothesis that artemisinin resistance may be exacerbated by interactions between PfATP6 and PfMDR1 and for epidemiological studies to monitor emerging resistance are discussed.

  14. Temporal expression of transporters and receptors in a rat primary co-culture blood-brain barrier model.

    Science.gov (United States)

    Liu, Houfu; Li, Yang; Lu, Sijie; Wu, Yiwen; Sahi, Jasminder

    2014-10-01

    1. The more relevant primary co-cultures of brain microvessel endothelial cells and astrocytes (BMEC) are less utilized for screening of potential CNS uptake when compared to intestinal and renal cell lines. 2. In this study, we characterized the temporal mRNA expression of major CNS transporters and receptors, including the transporter regulators Pxr, Ahr and Car in a rat BMEC co-cultured model. Permeability was compared with the Madin-Darby canine kidney (MDCKII)-MDR1 cell line and rat brain in situ perfusion model. 3. Our data demonstrated differential changes in expression of individual transporters and receptors over the culture period. Expression of ATP-binding cassette transporters was better retained than that of solute carrier transporters. The insulin receptor (IR) was best maintained among investigated receptors. AhR demonstrated high mRNA expression in rat brain capillaries and expression was better retained than Pxr or Car in culture. Mdr1b expression was up-regulated during primary culture, albeit Mdr1a mRNA levels were much higher. P-gp and Bcrp-1 were highly expressed and functional in this in vitro system. 4. Permeability measurements with 18 CNS marketed drugs demonstrated weak correlation between rBMEC model and rat in situ permeability and moderate correlation with MDCKII-MDR1 cells. 5. We have provided appropriate methodologies, as well as detailed and quantitative characterization data to facilitate improved understanding and rational use of this in vitro rat BBB model. PMID:24827375

  15. The expression and significance of multi-drug resistance genes in breast cancer stem cells%乳腺癌干细胞多药耐药基因的表达及意义

    Institute of Scientific and Technical Information of China (English)

    Zhi Li; Chunping Liu; Yanli He; Jinghui Zhang; Tao Huang

    2008-01-01

    Objective:To approach the expressions of MDR1 and BCRP in breast cancer stem cells and differentiated cells.Methods:The breast cancer stem calls were separated from human breast cancer primary tissues and MCF-7 by flow cytometry.Then we measured the expressions of MDR1 and BCRP with different subset cells by Realtime-PCR.Results:Contrasted with breast cancer differentiated cells,the expressions of MDR1 and BCRP in breast cancer stem calls were higher (P<0.01),and the proportion of stem cells rose after chemotherapy (P<0.01).Conclusion:Contrasted with breast cancer differentiated cells,breast cancer stem cells have stronger ability of clrug-resistanca with higher level of multi-drug resistance genes,and it is one of key points for chemotherapy failure of breast cancer.

  16. Is Resistance Useless? Multidrug Resistance and Collateral Sensitivity

    OpenAIRE

    Hall, Matthew D.; Handley, Misty D.; Gottesman, Michael M.

    2009-01-01

    When cancer cells develop resistance to chemotherapeutics, it is frequently conferred by the ATP-dependent efflux pump P-glycoprotein (MDR1, P-gp, ABCB1). P-gp can efflux a wide range of cancer drugs; thus its expression confers cross-resistance, termed multidrug resistance (MDR), to a wide range of drugs. Strategies to overcome this resistance have been actively sought for over 30 years, yet no clinical solutions exist. A less understood aspect of MDR is the hypersensitivity of resistant can...

  17. Regulation and expression of multidrug resistance (MDR) transcripts in the intestinal epithelium

    OpenAIRE

    Li, M.; Hurren, R; Zastawny, R. L.; Ling, V; Buick, R. N.

    1999-01-01

    A paucity of information exists on the regulation of gene expression in the undifferentiated intestine. The intestinal epithelium is one of the few normal tissues expressing the multidrug resistance (MDR) genes that confer the multidrug resistant phenotype to a variety of tumours. Expression of mdr1a has been observed in the primitive rat intestinal epithelial cell line, IEC-18. It is hypothesized that characterization of MDR gene expression in IEC-18 cells will provide insight into gene regu...

  18. Killing Effects of Adenovirus Mediated mdr1-CD∷UPP Gene on Resistant Ovarian Cancer%腺病毒介导的靶向自杀基因对卵巢癌耐药细胞株的杀伤作用

    Institute of Scientific and Technical Information of China (English)

    卢实; 孙敬霞; 王晓翊; 肖蓝; 王泽华

    2007-01-01

    目的 研究多药耐药基因1(mdr1)调控的胞嘧啶脱氨酶-尿嘧啶磷酸核糖转移酶融合基因(CD∷UPP)联合5-氟胞嘧啶(5-FC)后对卵巢癌紫杉醇耐药细胞株生长的影响.方法 以复制缺陷型重组腺病毒为载体,将mdr1-CD∷UPP基因分别转染2对人卵巢癌紫杉醇耐药细胞株A2780/Taxol、SKOV3/Taxol及非耐药细胞株A2780和SKOV3,加入含5-FC的培养液培养,5 d后噻唑蓝(MTT)法检测细胞存活率,观察旁观者效应.结果 5-FC对转基因耐药细胞的生长抑制作用明显高于转基因的非耐药细胞,随着5-FC浓度增加,抑制作用增强;通过旁观者效应5-FC可杀伤周围未转基因的耐药细胞.结论 mdr1-CD∷UPP靶向自杀基因联合5-FC后对紫杉醇耐药细胞具有显著的特异性杀伤作用.

  19. [Effect of Siwu decoction on function and expression of P-glycoprotein in Caco-2 cells].

    Science.gov (United States)

    Jiang, Yi; Ma, Zeng-chun; Huang, Xian-ju; You, Qing; Tan, Hong-ling; Wang, Yu-guang; Liang, Qian-de; Tang, Xiang-lin; Xiao, Cheng-rong; Gao, Yue

    2015-03-01

    To study the effect of Siwu decoction on the function and expression of P-glycoprotein (P-gp) in Caco-2 cells. The Real-time quantitative poly-merase chain reaction (Q-PCR) was used to analyze the mRNA expression of MDR1 gene in Caco-2 cells. Flow cytometer was used to study the effect of Siwu decoction on the uptake of Rhodamine 123 in Caco-2 cells, in order to evaluate the efflux function of P-gp. Western blotting method was used to detect the effect of Siwu decoction on the P-gp protein expression of Caco-2 cells. Compared with the blank control group, after Caco-2 incubation with Siwu decoction at concentrations of 3.3, 5.0, 10.0 g x L(-1) for 24, 48, 72 h, the mRNA expression of MDR1 was up-regulated, suggesting the effect of Siwu decoction in inducing the expression of MDR1. After the administration with Siwu decoction in Caco-2 cells for 48 h, the uptake of Rhodamine 123 in Caco-2 cells decreased by respectively 16.6%, 22.1% (P P P-gp efflux function of Caco-2 cells. After the incubation of Caco-2 cells with Siwu decoction for 48 h, the P-gp protein expression on Caco-2 cell emebranes, demonstrating the effect of Siwu decoction in inducing the protein expression of P-gp.

  20. Inhibition of multixenobiotic resistance transporters (MXR) by silver nanoparticles and ions in vitro and in Daphnia magna.

    Science.gov (United States)

    Georgantzopoulou, Anastasia; Cambier, Sébastien; Serchi, Tommaso; Kruszewski, Marcin; Balachandran, Yekkuni L; Grysan, Patrick; Audinot, Jean-Nicolas; Ziebel, Johanna; Guignard, Cédric; Gutleb, Arno C; Murk, AlberTinka J

    2016-11-01

    The P-glycoprotein (P-gp, ABCB1) and multidrug resistance associated protein 1 (MRP1), important members of the ABC (ATP-binding cassette) transporters, protect cells and organisms via efflux of xenobiotics and are responsible for the phenomenon of multidrug or multixenobiotic resistance (MXR). In this study we first evaluated, in vitro, the interaction of silver nanoparticles (Ag NPs, 20, 23 and 27nm), Ag 200nm particles and Ag ions (AgNO3) with MXR efflux transporters using MDCKII and the P-gp over-expressing MDCKII-MDR1 cells and calcein-AM as a substrate of the transporters. Next the in vivo modulation of MXR activity was studied in Daphnia magna juveniles with the model P-gp and MRP1 inhibitors verapamil-HCl and MK571, respectively. The common environmental contaminants perfluorooctane sulfonate and bisphenol A, previously observed to interfere with the P-gp in vitro, also inhibited the efflux of calcein in vivo. Small-sized Ag NPs (with biomolecules present on the surface) and AgNO3 inhibited the MXR activity in daphnids and MDCKII-MDR1 cells, but abcb1 gene expression remained unchanged. Both Ag NPs and dissolved ions contributed to the effects. This study provides evidence of the interference of Ag NPs and AgNO3 with the MXR activity both in vitro and in D. magna, and should be taken into account when Ag NP toxicity is assessed. PMID:27376922

  1. MDR1基因转染的骨髓单个核细胞对放疗后造血功能重建的研究%Investigation of post-radiotherapeutic hematopoietic reconstruction mediated by multidrug resistance gene 1 transfected bone marrow mononuclear cells

    Institute of Scientific and Technical Information of China (English)

    孔祥如; 王珊; 李圆; 张秀亚; 王江波

    2009-01-01

    目的 研究BALB/c小鼠放射治疗后经尾静脉回输携带多药耐药MDR1基因的骨髓单个核细胞(bone marrow mononuclear cells,BM-MNCs)对造血功能重建的影响.方法 BAB/c近交系小鼠32只,随机分为4组:正常对照组、空白对照组、阴性对照组和实验组.正常对照组不做任何处理,其他3组首先接受1.5Gy60Co-γ射线全身照射,空白对照组尾静脉回输等量生理盐水,阴性对照组经尾静脉回输未转染MDR1基因BM-MNCs,实验组回输已转染MDR1基因BM-MNCs.动态观察各组外周血变化.结果 同种异体回输后第七天,阴性对照组和实验组与空白对照组比较均表现为白细胞恢复提前.实验组7、10、14 d白细胞计数分别为(2.9±0.3)×109/L、(3.2±0.2)×109/L、(4.2±0.3)×109/L,阴性对照组为(2.7±0.2)×109/L、(2.8±0.2)×109/L、(3.5±0.3)×109/L,实验组与阴性对照组比较,白细胞数量增加,差异有统计学意义(t=2.21、3.53、4.73,P<0.05),14 d后差异无统计学意义(t=0.79,P>0.05).结论 同种异体携MDR1基因的骨髓单个核细胞移植,能在早期显著提高外周血白细胞数量,利于骨髓造血微环境恢复,加快辐射损伤后骨髓早期造血功能重建.%Objective To investigate the post-radiotherapeutic hematopoietic reconstruction mediated by multidrug resistance gene 1 (MDR1) transfected bone marrow mononuclear cells (BM-MNCs).Methods Thirty-two BALB/c mice were randomly divided into four groups (n=8/group):normal group,blank control group,negative control group and transfection group.Mice in the blank control group,negative group and transduced group accepted 1.5Gy60Co-γ radiotherapy.After radiotherapy,normal BM-MNCs were given to mice in the blank control group;normal saline was given to mice in the negative control group by tail vein injection:MDR1 tramfected BM-MNCs were given to mice in the transduced group by tail vein injection.The following peripherals blood changes in each group were observed and

  2. The potential influence of multidrug resistance 1(MDR1) gene polymorphisms on the steady blood concentration and therapeutic effects of duloxetine in patients with depression%抑郁症患者多药耐药基因多态性对度洛西汀稳态血药浓度和临床疗效的影响

    Institute of Scientific and Technical Information of China (English)

    徐莉萍; 李佑辉; 谢永标; 周志凌

    2011-01-01

    Objective To explore the potential influence of MDR1 gene polymorphisms, induding exon 26 C3435T and exon 21 G2677T, on the blood concentration and therapeutic effects of duloxetine in patients with depression.Methods The diagnosis of depression was made based on the Chinese Classification and Diagnosis of Mental Diseases-3rd edition. One hundred twenty depressed patients were received duloxetine treatment for 8 weeks. The patients were assessed and rated by 24-item Hamilton depression rating scale before and after the treatment, and the blood drug levels were assayed at 8th week. MDR1 variants G2677T and C3435T were detected using RFLP. Results After 8 week treatment, there were statistical significances in the steady blood concentration and therapeutic response to duloxetine in patients with different MDR1 variants G2677T (P < 0. 05), and patients with TT genotype had higher concentration of duloxetine compared with patients with GC or GG genotype[( 34. 22 ± 2. 41 ) ng/mL, ( 31.49 ± 3.32 ) ng/mL, ( 32. 40 ± 2. 89 ) ng/mL, P < 0. 05 )and had better therapeutical outcomes than patients with GG genotype (mean rank70. 38 vs 51.65, P < 0. 05 ). There were statistical significances in the steady blood concentration and therapeutic response to duloxetine in patients with different C3435T variants ( F = 6.93, P < 0. 01; x2 =6. 36, P =0. 04). Patients with TT genotype had higher concentration of dulo xetine compared with patients with CC or CT genotype [ (33. 99 ± 2. 40) ng/mL, (31.53 ± 3. 41 ) ng/mL, (32. 32 ±2. 96) ng/mL, P < 0. 05 ] and had better therapeutical outcomes than patients with CC genotype (mean rank 69. 11 vs 51.16, P <0. 05). Conclusions MDR1 gene polymorphisms are associated with the steady blood concentration and the anti-depression effects of duloxetine.%目的 探讨抑郁症患者多药耐药1(multidrug resistance 1, MDR1)基因的G2677T和C3435T位点多态性对度洛西汀稳态血药浓度和临床疗效的影响.方法 120例

  3. Quercetin as a Potential Modulator of P-Glycoprotein Expression and Function in Cells of Human Pancreatic Carcinoma Line Resistant to Daunorubicin

    Directory of Open Access Journals (Sweden)

    Piotr Dziegiel

    2010-02-01

    Full Text Available P-glycoprotein (P-gp is one of the ABC transporters responsible for the resistance of several tumours to successful chemotherapy. Numerous agents are capable of interfering with the P-gp-mediated export of drugs but unfortunately most of them produce serious side effects. Some plant polyphenols, including the flavonol quercetin (Q, manifest anti-neoplastic activity mainly due to their influence on cell cycle control and apoptosis. Reports are also available which show that Q may intensify action of cytostatic drugs and suppress the multidrug resistance (MDR phenomenon. The study aimed at determination if Q sensitizes cells resistant to daunorubicin (DB through its effect on P-gp expression and action. The experiments were conducted on two cell lines of human pancreatic carcinoma, resistant to DB EPP85-181RDB and sensitive EPP85-181P as a comparison. Cells of both lines were exposed to selected concentrations of Q and DB, and then membranous expression of P-gp and its transport function were examined. The influence on expression of gene for P-gp (ABCB1 was also investigated. Results of the studies confirmed that Q affects expression and function of P-gp in a concentration-dependent manner. Moreover it decreased expression of ABCB1. Thus, Q may be considered as a potential modulator of P-gp.

  4. Molecular Investigation of Plasmodium falciparum multi-drug resistance gene in Bioko Island,Equatorial Guinea%赤道几内亚Bioko岛的恶性疟原虫多药抗性基因(pfMDR-1)的研究

    Institute of Scientific and Technical Information of China (English)

    卢丹洁; 陈江涛; 谢东德; 杨辉; 詹小芬; 杨惠钿; 杨立业; 陆志为; Santiago-m Monte-Nguba

    2014-01-01

    目的 对赤道几内亚Bioko岛上恶性疟原虫多药抗性基因(pfMDR-1)进行分析,为Bioko 岛的疟疾防控和治疗提供依据.方法 2012年雨季期间采集的恶性疟原虫感染患者样本151份,用巢式PCR技术特异性扩增N86Y、E130K、Y184F、S1034C、N1042D、V1109I、D1246Y耐药分子标记的pfMDR-1基因片段,然后进行测序分析.结果 虫株中共发现了4种不同的单倍型:YEY/SNVD、NEF/SNVD、YEF/SNVD和NEY/SNVD.91.39% (138/151)的样本发现了耐药性位点突变,包括3.31% (5/151)的86Y,29.80%的184F,和58.29%(88/151)的双重突变86Y/184F.结论 结果表明赤道几内亚Bioko岛上的恶性疟原虫株存在较高比例耐药基因突变和耐药复合基因突变,为当地的抗疟疾选用药物提供指导.

  5. Aliskiren toxicity in juvenile rats is determined by ontogenic regulation of intestinal P-glycoprotein expression

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, Peter, E-mail: peterk.hoffmann@novartis.com [Preclinical Safety, Novartis Institutes for BioMedical Research, East Hanover, NJ (United States); Beckman, David; McLean, Lee Anne [Preclinical Safety, Novartis Institutes for BioMedical Research, East Hanover, NJ (United States); Yan, Jing-He [Drug Metabolism and Pharmacokinetics, Novartis Institutes for BioMedical Research, East Hanover, NJ (United States)

    2014-02-15

    Juvenile rat toxicity studies with the direct renin inhibitor aliskiren were initiated to support treatment in the pediatric population. In Study 1, aliskiren was administered orally to juvenile rats at doses of 0, 30, 100 or 300 mg/kg/day with repeated dosing from postpartum day (PPD) 8 to PPD 35/36. In-life, clinical pathology, anatomic pathology, and toxicokinetics evaluations were performed. In Study 2, single oral doses of aliskiren (0, 100 or 300 mg/kg) were given to 14-, 21-, 24-, 28-, 31- or 36-day-old rats; in-life data and toxicokinetics were evaluated. Study 3 was a single dose (3 mg/kg i.v.) pharmacokinetic study in juvenile rats on PPD 8, 14, 21 and 28. In Study 4, naïve rats were used to investigate ontogenic changes of the multidrug-resistant protein 1 (MDR1) and the organic anion transporting polypeptide (OATP) mRNA in several organs. Oral administration of aliskiren at 100 and 300 mg/kg caused unexpected mortality and severe morbidity in 8-day-old rats. Aliskiren plasma and tissue concentrations were increased in rats aged 21 days and younger. Expression of MDR1 and OATP mRNA in the intestine, liver and brain was significantly lower in very young rats. In conclusion, severe toxicity and increased exposure in very young rats after oral administration of aliskiren are considered to be the result of immature drug transporter systems. Immaturity of MDR1 in enterocytes appears to be the most important mechanism responsible for the high exposure. - Highlights: • Aliskiren was orally administered to juvenile rats. • Unexpected severe toxicity and acute mortality occurred in rats aged 8 days. • Toxicity was associated with increased aliskiren plasma and tissue exposure. • Developmental changes of exposure correlated with ontogeny of transporters. • Immaturity of MDR1 in enterocytes causes increased exposure in very young rats.

  6. Aliskiren toxicity in juvenile rats is determined by ontogenic regulation of intestinal P-glycoprotein expression

    International Nuclear Information System (INIS)

    Juvenile rat toxicity studies with the direct renin inhibitor aliskiren were initiated to support treatment in the pediatric population. In Study 1, aliskiren was administered orally to juvenile rats at doses of 0, 30, 100 or 300 mg/kg/day with repeated dosing from postpartum day (PPD) 8 to PPD 35/36. In-life, clinical pathology, anatomic pathology, and toxicokinetics evaluations were performed. In Study 2, single oral doses of aliskiren (0, 100 or 300 mg/kg) were given to 14-, 21-, 24-, 28-, 31- or 36-day-old rats; in-life data and toxicokinetics were evaluated. Study 3 was a single dose (3 mg/kg i.v.) pharmacokinetic study in juvenile rats on PPD 8, 14, 21 and 28. In Study 4, naïve rats were used to investigate ontogenic changes of the multidrug-resistant protein 1 (MDR1) and the organic anion transporting polypeptide (OATP) mRNA in several organs. Oral administration of aliskiren at 100 and 300 mg/kg caused unexpected mortality and severe morbidity in 8-day-old rats. Aliskiren plasma and tissue concentrations were increased in rats aged 21 days and younger. Expression of MDR1 and OATP mRNA in the intestine, liver and brain was significantly lower in very young rats. In conclusion, severe toxicity and increased exposure in very young rats after oral administration of aliskiren are considered to be the result of immature drug transporter systems. Immaturity of MDR1 in enterocytes appears to be the most important mechanism responsible for the high exposure. - Highlights: • Aliskiren was orally administered to juvenile rats. • Unexpected severe toxicity and acute mortality occurred in rats aged 8 days. • Toxicity was associated with increased aliskiren plasma and tissue exposure. • Developmental changes of exposure correlated with ontogeny of transporters. • Immaturity of MDR1 in enterocytes causes increased exposure in very young rats

  7. Association of drug transporter expression with mortality and progression-free survival in stage IV head and neck squamous cell carcinoma.

    Directory of Open Access Journals (Sweden)

    Rolf Warta

    Full Text Available Drug transporters such as P-glycoprotein (ABCB1 have been associated with chemotherapy resistance and are considered unfavorable prognostic factors for survival of cancer patients. Analyzing mRNA expression levels of a subset of drug transporters by quantitative reverse transcription polymerase chain reaction (qRT-PCR or protein expression by tissue microarray (TMA in tumor samples of therapy naïve stage IV head and neck squamous cell carcinoma (HNSCC (qRT-PCR, n = 40; TMA, n = 61, this in situ study re-examined the significance of transporter expression for progression-free survival (PFS and overall survival (OS. Data from The Cancer Genome Atlas database was used to externally validate the respective findings (n = 317. In general, HNSCC tended to lower expression of drug transporters compared to normal epithelium. High ABCB1 mRNA tumor expression was associated with both favorable progression-free survival (PFS, p = 0.0357 and overall survival (OS, p = 0.0535. Similar results were obtained for the mRNA of ABCC1 (MRP1, multidrug resistance-associated protein 1; PFS, p = 0.0183; OS, p = 0.038. In contrast, protein expression of ATP7b (copper transporter ATP7b, mRNA expression of ABCG2 (BCRP, breast cancer resistance protein, ABCC2 (MRP2, and SLC31A1 (hCTR1, human copper transporter 1 did not correlate with survival. Cluster analysis however revealed that simultaneous high expression of SLC31A1, ABCC2, and ABCG2 indicates poor survival of HNSCC patients. In conclusion, this study militates against the intuitive dogma where high expression of drug efflux transporters indicates poor survival, but demonstrates that expression of single drug transporters might indicate even improved survival. Prospectively, combined analysis of the 'transportome' should rather be performed as it likely unravels meaningful data on the impact of drug transporters on survival of patients with HNSCC.

  8. Nuclear Multidrug-Resistance Related Protein 1 Contributes to Multidrug-Resistance of Mucoepidermoid Carcinoma Mainly via Regulating Multidrug-Resistance Protein 1: A Human Mucoepidermoid Carcinoma Cells Model and Spearman's Rank Correlation Analysis

    OpenAIRE

    Bolei Cai; Ye Miao; Yuan Liu; Xiaofang Xu; Sumin Guan; Junzheng Wu; Yanpu Liu

    2013-01-01

    BACKGROUND: Multidrug resistance-related protein 1 (MRP1/ABCC1) and multidrug resistance protein 1 (MDR1/P-glycoprotein/ABCB1) are both membrane-bound drug transporters. In contrast to MDR1, MRP1 also transports glutathione (GSH) and drugs conjugated to GSH. Due to its extraordinary transport properties, MRP1/ABCC1 contributes to several physiological functions and pathophysiological incidents. We previously found that nuclear translocation of MRP1 contributes to multidrug-resistance (MDR) of...

  9. Piperine activates human pregnane X receptor to induce the expression of cytochrome P450 3A4 and multidrug resistance protein 1

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yue-Ming; Lin, Wenwei; Chai, Sergio C.; Wu, Jing; Ong, Su Sien [Department of Chemical Biology and Therapeutics, St. Jude Children' s Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105 (United States); Schuetz, Erin G. [Department of Pharmaceutical Sciences, St. Jude Children' s Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105 (United States); Chen, Taosheng, E-mail: taosheng.chen@stjude.org [Department of Chemical Biology and Therapeutics, St. Jude Children' s Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105 (United States)

    2013-10-01

    Activation of the pregnane X receptor (PXR) and subsequently its target genes, including those encoding drug transporters and metabolizing enzymes, while playing substantial roles in xenobiotic detoxification, might cause undesired drug-drug interactions. Recently, an increased awareness has been given to dietary components for potential induction of diet–drug interactions through activation of PXR. Here, we studied, whether piperine (PIP), a major component extracted from the widely-used daily spice black pepper, could induce PXR-mediated expression of cytochrome P450 3A4 (CYP3A4) and multidrug resistance protein 1 (MDR1). Our results showed that PIP activated human PXR (hPXR)-mediated CYP3A4 and MDR1 expression in human hepatocytes, intestine cells, and a mouse model; PIP activated hPXR by recruiting its coactivator SRC-1 in both cellular and cell-free systems; PIP bound to the hPXR ligand binding domain in a competitive ligand binding assay in vitro. The dichotomous effects of PIP on induction of CYP3A4 and MDR1 expression observed here and inhibition of their activity reported elsewhere challenges the potential use of PIP as a bioavailability enhancer and suggests that caution should be taken in PIP consumption during drug treatment in patients, particularly those who favor daily pepper spice or rely on certain pepper remedies. - Highlights: • Piperine induces PXR-mediated CYP3A4 and MDR1 expression. • Piperine activates PXR by binding to PXR and recruiting coactivator SRC-1. • Piperine induces PXR activation in vivo. • Caution should be taken in piperine consumption during drug treatment.

  10. Expression and significance of multidrug resistance gene in the colorectal cancer tissues

    Institute of Scientific and Technical Information of China (English)

    Zhi-Hong Lu; Min-Hong Pang

    2015-01-01

    Objective:To explore the correlation of expressions of MDR1/P-gp and CerbB-2 in the colorectal cancer tissues and their clinical significance.Methods:A total of 86 colorectal cancer tissues specimens were included in the study. The immunohistochemical S-P method was used to detect the expressions of P-gp and CerbB-2, and their correlations were analyzed.Results:The positive rates of the expressions of MDR1/P-gp and CerbB-2 were 36% (31/86) and 28% (24/86), respectively. The positive expression rate of CerbB-2 in the colorectal cancer tissues at a clinical stage of III was significantly higher than that at stage I and II. The positive expression rates of MDR1/P-gp and CerbB-2 in the colorectal cancer tissues with axillary lymph node metastasis were significantly higher than those in the tissues without axillary lymph node metastasis. In the P-gp positive expression group, the positive rate of CerbB-2 was 75.5% (37/49), while the negative rate of CerbB-2 was 24.48% (12/49), and the difference was statistically significant (P<0.01). P-gp had a certain positive correlation with the positive expression rate of CerbB-2. Conclusions:P-gp and CerbB-2 play a certain role in the occurrence of multidrug resistance of colorectal cancer, and their expressions are correlated; therefore, the combination detection can provide an evidence for the chemotherapy choice of colorectal cancer.

  11. Chemoresistance of CD133{sup +} colon cancer may be related with increased survivin expression

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Mi-Ra; Ji, Sun-Young; Mia-Jan, Khalilullah [Department of Pathology, Yonsei University, Wonju College of Medicine, Wonju (Korea, Republic of); Cho, Mee-Yon, E-mail: meeyon@yonsei.ac.kr [Department of Pathology, Yonsei University, Wonju College of Medicine, Wonju (Korea, Republic of); Institute of Genomic Cohort, Yonsei University, Wonju College of Medicine, Wonju (Korea, Republic of)

    2015-07-31

    CD133, putative cancer stem cell marker, deemed to aid chemoresistance. However, this claim has been challenged recently and we previously reported that patients with CD133{sup +} colon cancer have benefit from 5-fluorouracil (5-FU) chemotherapy incontrast to no benefit in patients with CD133{sup −} cancer. To elucidate the role of CD133 expression in chemoresistance, we silenced the CD133 expression in a colon cancer cell line and determined its effect on the biological characteristics downstream. We comparatively analyzed the sequential changes of MDR1, ABCG2, AKT1 and survivin expression and the result of proliferation assay (WST-1 assay) with 5-FU treatment in CD133{sup +} and siRNA-induced CD133{sup −} cells, derived from Caco-2 colon cancer cell line. 5-FU treatment induced significantly increase of the mRNA expression of MDR1, ABCG2 and AKT1genes, but not protein level. CD133 had little to no effect on the mRNA and protein expression of these genes. However, survivin expression at mRNA and protein level were significantly increased in CD133{sup +} cells compared with siRNA-induced CD133-cells and Mock (not sorted CD133{sup +} cells) at 96 h after siRNA transfection. The cytotoxicity assay demonstrated notable increase of chemoresistance to 5-FU treatment (10 μM) in CD133{sup +} cells at 96 h after siRNA transfection. From this study, we conclude that CD133{sup +} cells may have chemoresistance to 5-FU through the mechanism which is related with survivin expression, instead of MDR1, ABCG2 and AKT1 expression. Therefore a survivin inhibitor can be a new target for effective treatment of CD133{sup +} colon cancer. - Highlights: • We evaluate the role of CD133 in chemoresistance of colon cancer. • We compared the chemoresistance of CD133{sup +} cells and siRNA-induced CD133{sup −} cells. • CD133 had little to no effect on MDR1, ABCG2 and AKT1 expression. • Survivin expression and chemoresistance were increased in CD133{sup +} colon cancer cells.

  12. A Chemical Probe that Labels Human Pluripotent Stem Cells

    Directory of Open Access Journals (Sweden)

    Nao Hirata

    2014-03-01

    Full Text Available A small-molecule fluorescent probe specific for human pluripotent stem cells would serve as a useful tool for basic cell biology research and stem cell therapy. Screening of fluorescent chemical libraries with human induced pluripotent stem cells (iPSCs and subsequent evaluation of hit molecules identified a fluorescent compound (Kyoto probe 1 [KP-1] that selectively labels human pluripotent stem cells. Our analyses indicated that the selectivity results primarily from a distinct expression pattern of ABC transporters in human pluripotent stem cells and from the transporter selectivity of KP-1. Expression of ABCB1 (MDR1 and ABCG2 (BCRP, both of which cause the efflux of KP-1, is repressed in human pluripotent stem cells. Although KP-1, like other pluripotent markers, is not absolutely specific for pluripotent stem cells, the identified chemical probe may be used in conjunction with other reagents.

  13. Interspecies variability in expression of hepatobiliary transporters across human, dog, monkey, and rat as determined by quantitative proteomics.

    Science.gov (United States)

    Wang, Li; Prasad, Bhagwat; Salphati, Laurent; Chu, Xiaoyan; Gupta, Anshul; Hop, Cornelis E C A; Evers, Raymond; Unadkat, Jashvant D

    2015-03-01

    We quantified, by liquid chromatography tandem mass spectrometry, transporter protein expression of BSEP, MATE1, MRP3, MRP4, NTCP, and OCT1 in our human liver bank (n = 55) and determined the relationship between protein expression and sex, age and genotype. These data complement our previous work in the same liver bank where we quantified the protein expression of OATPs, BCRP, MDR1, and MRP2. In addition, we quantified and compared the interspecies differences in expression of the hepatobiliary transporters, corresponding to the above human transporters, in liver tissue and hepatocytes of male beagle dogs, cynomolgus monkeys, Sprague-Dawley rats, and Wistar rats. In all the species, the sinusoidal OATPs/Oatps were the most abundant hepatic transporters. However, there were notable interspecies differences in the relative abundance of the remaining transporters. For example, the next most abundant transporter in humans and monkeys was OCT1/Oct1, whereas it was Mrp2 and Ntcp in dogs/Wistar rats and Sprague-Dawley rats, respectively. In contrast, the protein expression of the efflux transporters BCRP/Bcrp, MDR1/Mdr1, MRP3/Mrp3, MRP4/Mrp4, and MATE1/Mate1 was much lower across all the species. For most transporters, the expression in the liver tissues was comparable to that in the unplated cryopreserved hepatocytes. These data on human liver transporter protein expression complete the picture of the expression of major human hepatobiliary transporters important in drug disposition and toxicity. In addition, the data on expression of the corresponding hepatobiliary transporters in preclinical species will be helpful in interpreting and extrapolating pharmacokinetic, pharmacological, and toxicological results from preclinical studies to humans. PMID:25534768

  14. Expression

    Directory of Open Access Journals (Sweden)

    Wang-Xia Wang

    2014-02-01

    Full Text Available The miR-15/107 family comprises a group of 10 paralogous microRNAs (miRNAs, sharing a 5′ AGCAGC sequence. These miRNAs have overlapping targets. In order to characterize the expression of miR-15/107 family miRNAs, we employed customized TaqMan Low-Density micro-fluid PCR-array to investigate the expression of miR-15/107 family members, and other selected miRNAs, in 11 human tissues obtained at autopsy including the cerebral cortex, frontal cortex, primary visual cortex, thalamus, heart, lung, liver, kidney, spleen, stomach and skeletal muscle. miR-103, miR-195 and miR-497 were expressed at similar levels across various tissues, whereas miR-107 is enriched in brain samples. We also examined the expression patterns of evolutionarily conserved miR-15/107 miRNAs in three distinct primary rat brain cell preparations (enriched for cortical neurons, astrocytes and microglia, respectively. In primary cultures of rat brain cells, several members of the miR-15/107 family are enriched in neurons compared to other cell types in the central nervous system (CNS. In addition to mature miRNAs, we also examined the expression of precursors (pri-miRNAs. Our data suggested a generally poor correlation between the expression of mature miRNAs and their precursors. In summary, we provide a detailed study of the tissue and cell type-specific expression profile of this highly expressed and phylogenetically conserved family of miRNA genes.

  15. TRANSFECTED MDCK CELL LINE WITH ENHANCED EXPRESSION OF CYP3A4 AND P-GLYCOPROTEIN AS A MODEL TO STUDY THEIR ROLE IN DRUG TRANSPORT AND METABOLISM

    OpenAIRE

    Kwatra, Deep; Budda, Balasubramanyam; Vadlapudi, Aswani Dutt; Vadlapatla, Ramya Krishna; Pal, Dhananjay; Ashim K. Mitra

    2012-01-01

    The aim of this study was to characterize and utilize MDCK cell line expressing CYP3A4 and P-glycoprotein as an in vitro model for evaluating drug-herb and drug-drugs of abuse interactions. MDCK cell line simultaneously expressing P-gp and CYP3A4 (MMC) was developed and characterized by using expression and activity studies. Cellular transport study of 200 μM cortisol was performed to determine their combined activity. The study was carried across MDCK-WT, MDCK-MDR1 and MMC cell lines. Simila...

  16. eEF-2 Phosphorylation Down-Regulates P-Glycoprotein Over-Expression in Rat Brain Microvessel Endothelial Cells.

    Directory of Open Access Journals (Sweden)

    Xing Hua Tang

    Full Text Available We investigated whether glutamate, NMDA receptors, and eukaryote elongation factor-2 kinase (eEF-2K/eEF-2 regulate P-glycoprotein expression, and the effects of the eEF-2K inhibitor NH125 on the expression of P-glycoprotein in rat brain microvessel endothelial cells (RBMECs.Cortex was obtained from newborn Wistar rat brains. After surface vessels and meninges were removed, the pellet containing microvessels was resuspended and incubated at 37°C in culture medium. Cell viability was assessed by the MTT assay. RBMECs were identified by immunohistochemistry with anti-vWF. P-glycoprotein, phospho-eEF-2, and eEF-2 expression were determined by western blot analysis. Mdr1a gene expression was analyzed by RT-PCR.Mdr1a mRNA, P-glycoprotein and phospho-eEF-2 expression increased in L-glutamate stimulated RBMECs. P-glycoprotein and phospho-eEF-2 expression were down-regulated after NH125 treatment in L-glutamate stimulated RBMECs.eEF-2K/eEF-2 should have played an important role in the regulation of P-glycoprotein expression in RBMECs. eEF-2K inhibitor NH125 could serve as an efficacious anti-multidrug resistant agent.

  17. Liposome-mediated Functional Expression of Multiple Drug Resistance Gene in Human Bone Marrow CD34+ Cells

    Institute of Scientific and Technical Information of China (English)

    曹文静; 邹萍

    2004-01-01

    Summary: The expression and functional activity of multiple drug resistance (MDR1) gene in human normal bone marrow CD34+ cells was observed. Human normal bone marrow CD34+ cells were enriched with magnetic cell sorting (MACS) system, and then liposome-mediated MDR1 gene was transferred into bone marrow CD34+ cells. Fluorescence-activated cell sorter was used to evaluate the expression and functional activity of P-glycoprotein (P-gp) encoded by MDR1 gene. It was found that the purity of bone marrow CD34 + cells was approximately (91±4.56) % and recovery rate was (72.3±2.36) % by MACS. The expression of P-gp in the transfected CD34+ cells was obviously higher than that in non-transfected CD34+ cells. The amount of P-gp in non-transfected CD34+ cells was (11.2±2.2) %, but increased to (23.6±2.34) % 48 h after gene transfection (P<0.01). The amount of P-gp was gradually decreased to the basic level one week later. The accumulation and extrusion assays showed that the overexpression of P-gp could efflux Rh-123 out of cells and there was low fluorescence within the transfected cells. The functional activity of P-gp could be inhibited by 10 μg/ml verapamil. It was suggested that the transient and highly effective expression and functional activity of P-gp could be obtained by liposome-mediated MRD1 transferring into human normal bone marrow CD34 + cells.

  18. Glucose deprivation induces chemoresistance in colorectal cancer cells by increasing ATF4 expression

    Science.gov (United States)

    Hu, Ya-Ling; Yin, Yuan; Liu, He-Yong; Feng, Yu-Yang; Bian, Ze-Hua; Zhou, Le-Yuan; Zhang, Ji-Wei; Fei, Bo-Jian; Wang, Yu-Gang; Huang, Zhao-Hui

    2016-01-01

    AIM: To investigate the role of activating transcription factor 4 (ATF4) in glucose deprivation (GD) induced colorectal cancer (CRC) drug resistance and the mechanism involved. METHODS: Chemosensitivity and apoptosis were measured under the GD condition. Inhibition of ATF4 using short hairpin RNA in CRC cells under the GD condition and in ATF4-overexpressing CRC cells was performed to identify the role of ATF4 in the GD induced chemoresistance. Quantitative real-time RT-PCR and Western blot were used to detect the mRNA and protein expression of drug resistance gene 1 (MDR1), respectively. RESULTS: GD protected CRC cells from drug-induced apoptosis (oxaliplatin and 5-fluorouracil) and induced the expression of ATF4, a key gene of the unfolded protein response. Depletion of ATF4 in CRC cells under the GD condition can induce apoptosis and drug re-sensitization. Similarly, inhibition of ATF4 in the ATF4-overexpressing CRC cells reintroduced therapeutic sensitivity and apoptosis. In addition, increased MDR1 expression was observed in GD-treated CRC cells. CONCLUSION: These data indicate that GD promotes chemoresistance in CRC cells through up-regulating ATF4 expression. PMID:27468213

  19. Combination effects of nano-TiO2 and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on biotransformation gene expression in the liver of European sea bass Dicentrarchus labrax.

    Science.gov (United States)

    Vannuccini, Maria Luisa; Grassi, Giacomo; Leaver, Michael J; Corsi, Ilaria

    2015-01-01

    The aim of present study was to investigate the influence of titanium dioxide nanoparticles (nano-TiO2, Aeroxide® P25) on 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) dependent biotransformation gene expression in liver of juvenile European sea bass Dicentrarchus labrax. An in vivo 7day waterborne exposure was performed with nano-TiO2 (1mg/L) and 2,3,7,8-TCDD (46pg/L), singly and in combination. The mRNA expression of aryl hydrocarbon receptor repressor (Ahrr), estrogen receptor (erβ2), ABC transport proteins as Abcb1, Abcc1-c2-g2, cytochrome P450 (cyp1a), glutathione-s-transferase (gsta), glutathione reductase (gr) and engulfment and motility (ELMO) domain-containing protein 2 (elmod2) was investigated. Ahrr, erβ2, abcc1 and abcg2 resulted down-regulated with respect to controls in all experimental groups. Co-exposure to nano-TiO2 and 2,3,7,8-TCDD caused a further significant down regulation of ahrr, erβ2, Abcb1 and Abcc2 compared to single chemical exposure (nano-TiO2 or 2,3,7,8-TCDD alone). No effects were observed for 2,3,7,8-TCDD and nano-TiO2 alone in abcb1 gene, while abcc2 was down-regulated by nano-TiO2 alone. Cyp1a, gst and elmod2 genes were up-regulated by 2,3,7,8-TCDD and to a similar extent after co-exposure. Overall the results indicate that nano-TiO2 is unlikely to interfere with 2,3,7,8-TCDD-dependent biotransformation gene expression in the liver of European sea bass, although the effects of co-exposure observed in ABC transport mRNAs might suggest an impact on xenobiotic metabolite disposition and transport in European sea bass liver. PMID:26235595

  20. Increases in doxorubicin sensitivity and radioiodide uptake by transfecting shMDR and sodium/iodide symporter gene in cancer cells expressing multidrug resistance

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Sohn Joo; Lee, Yong Jin; Lee, You La; Choi, Chang Ik; Lee, Sang Woo; Yoo, Jeong Soo; Ahn, Byeong Cheol; Lee, In Kyu; Lee, Jae Tae [Kyungpook National University, Daegu (Korea, Republic of)

    2007-06-15

    Multidrug resistance (MDR) of the cancer cells related to mdr1 gene expression can be effectively treated by selective short hairpin RNA for mdr1 gene (shMDR). Sodium/iodide symporter (NIS) gene is well known to have both reporter and therapeutic gene characteristics. We have co-transfected both shMDR and NIS gene into colon cancer cells (HCT15 cell) expressing MDR and Tc-99m sestamibi and I-125 uptake were measured. In addition, cytotoxic effects of doxorubicin and I-131 therapy were also assessed after transfection. At first, shMDR was transfected with liposome reagent into human embryonic kidney cells (HEK293) and HCT cells. shMDR transfection was confirmed by RT-PCR and western blot analysis. Adenovirus expressing NIS (Ad-NIS) gene and shMDR (Ad-shMDR) were co-transfected with Ad-NIS into HCT15 cells. Forty-eight hours after infection, inhibition of P-gycoprotein (Pgp) function by shMDR was analyzed by a change of Tc-99m sestamibi uptake and doxorubicin cytotoxicity, and functional activity of induced NIS gene expression was assessed with I-125 uptake assay. In HEK293 cells transfected with shMDR, mdr1 mRNA and Pgp protein expressions were down regulated. HCT15 cells infected with 20 MOI of Ad-NIS was higher NIS protein expression than control cells. After transfection of 300 MOI of Ad-shMDR either with or without 10 MOI of Ad-NIS, uptake of Tc-99m sestamibi increased up to 1.5-fold than control cells. HCT15 cells infected with 10 MOI of Ad-NIS showed approximately 25-fold higher I-125 uptake than control cells. Cotransfection of Ad-shMDR and Ad-NIS resulted in enhanced cytotoxic by doxorubicin in HCT15 cells. I-131 treatment on HCT15 cells infected with 20 MOI of Ad-NIS revealed increased cytotoxic effect. Suppression of mdr1 gene expression, retention of Tc-99m sestamibi, enhanced doxorubicin cytotoxicity and increases in I-125 uptake were achieved in MDR expressing cancer cell by co-transfection of shMDR and NIS gene. Dual therapy with doxorubicin and

  1. Effects of hypoxia on expression of a panel of stem cell and chemoresistance markers in glioblastoma-derived spheroids

    DEFF Research Database (Denmark)

    Kolenda, Jesper; Jensen, Stine Skov; Aaberg-Jessen, Charlotte;

    2011-01-01

    ). Spheroids were formed in 21% and 1% O(2) in serum-free medium. The immunohistochemical panel included hypoxia (HIF-1α, HIF-2α), proliferation (Ki-67), and stem cell markers (CD133, podoplanin, Bmi-1, nestin, Sox-2) as well as markers related to chemoresistance (MGMT, TIMP-1, Lamp-1, MRP1, MDR-1......). As spheroids derived in hypoxia were smaller than in normoxia, a set of experiments was included in which the culturing time of hypoxic spheroids was extended to obtain equally sized spheroids. The results showed that expression of HIF-1α and HIF-2α was increased in hypoxia, whereas Ki-67 was reduced...

  2. Effects of Astragalus polysaccharides on P-glycoprotein efflux pump function and protein expression in H22 hepatoma cells in vitro

    Directory of Open Access Journals (Sweden)

    Tian Qing E

    2012-07-01

    Full Text Available Abstract Background Astragalus polysaccharides (APS are active constituents of Astragalus membranaceus. They have been widely studied, especially with respect to their immunopotentiating properties, their ability to counteract the side effects of chemotherapeutic drugs, and their anticancer properties. However, the mechanism by which APS inhibit cancer and the issue of whether that mechanism involves the reversal of multidrug resistance (MDR is not completely clear. The present paper describes an investigation of the effects of APS on P-glycoprotein function and expression in H22 hepatoma cell lines resistant to Adriamycin (H22/ADM. Methods H22/ADM cell lines were treated with different concentrations of APS and/or the most common chemotherapy drugs, such as Cyclophosphamid, Adriamycin, 5-Fluorouracil, Cisplatin, Etoposide, and Vincristine. Chemotherapeutic drug sensitivity, P-glycoprotein function and expression, and MDR1 mRNA expression were detected using MTT assay, flow cytometry, Western blotting, and quantitative RT-PCR. Results When used alone, APS had no anti-tumor activity in H22/ADM cells in vitro. However, it can increase the cytotoxicity of certain chemotherapy drugs, such as Cyclophosphamid, Adriamycin, 5-Fluorouracil, Cisplatin, Etoposide, and Vincristine, in H22/ADM cells. It acts in a dose-dependent manner. Compared to a blank control group, APS increased intracellular Rhodamine-123 retention and decreased P-glycoprotein efflux function in a dose-dependent manner. These factors were assessed 24 h, 48 h, and 72 h after administration. APS down regulated P-glycoprotein and MDR1 mRNA expression in a concentration-dependent manner within a final range of 0.8–500 mg/L and in a time-dependent manner from 24–72 h. Conclusion APS can enhance the chemosensitivity of H22/ADM cells. This may involve the downregulation of MDR1 mRNA expression, inhibition of P-GP efflux pump function, or both, which would decrease the expression

  3. Relationship between P-gp expression and clinical efficacy of transcatheter arterial embolization chemotherapy (TACE) in primary liver cancer and clinical significance%原发性肝癌 P-糖蛋白表达与肝动脉插管栓塞化疗疗效的关系及临床意义

    Institute of Scientific and Technical Information of China (English)

    吴照宇; 郭应兴; 雷进元; 于海东

    2015-01-01

    目的:检测肝癌细胞的多药耐药基因 MDR1及编码产物 P-gp(P-glycoprotein,P-gp)的表达并探讨其与原发性肝癌经肝动脉插管栓塞化疗(transcatheter arterial chemoembolization,TACE)疗效的关系及临床意义。方法选取2010年6月到2013年6月来我院接受手术治疗的108例原发性肝癌患者作为肝癌组研究对象,同时选取来我院行肝穿刺检查的50例健康者作为对照。采用实时荧光定量 PCR 测定各组肝组织中 MDR1的 mRNA 水平,并采用免疫组织化学法检测手术切除后的肝癌组织 P-gp 的表达。根据 P-gp 表达水平将患者分为耐药组和非耐药组,分析 P-gp 表达水平与原发性肝癌术后 TACE 治疗效果的关系。结果与对照组比较,肝癌组患者肝脏组织中 MDR1的 mRNA表达水平显著升高(P 2的患者76例,MDR1的 mRNA/正常水平<2的患者32例。免疫组织化学结果显示 P-gp 呈棕黄色,主要表达于肝癌细胞的细胞膜表面。其中 P-gp 蛋白阴性患者(非耐药组)35例,阳性患者(耐药组)73例。非耐药组患者化疗有效率(74.28%)明显高于耐药组患者(43.28%)(P <0.05)。非耐药组1、2年累积生存率为77.14%和42.86%,明显高于耐药组(54.12%和27.40%,P <0.05)。结论原发性肝癌组织中 MDR1编码产物 P-gp 异常过表达与肿瘤化疗耐药性相关,提示其可作为临床术后化疗用药的指导标志之一。%Objective To explore the relationship of MDR1 and its encoded product P-gp expressions with clinical efficacy of transcatheter arterial chemoembolization (TACE)in primary liver cancer and their clinical significance.Methods We selected 108 patients with primary liver cancer who came to our hospital between June 2010 and June 2013 as observation subjects.Meanwhile 50 healthy people in our hospital for liver biopsy were selected as controls.MDR1 mRNA level in observation group and control group was determined by real-time quantitative PCR.P-gp protein level was

  4. Astragaloside Ⅳ reduces the expression level of P-glycoprotein in multidrug-resistant human hepatic cancer cell lines.

    Science.gov (United States)

    Wang, Pei-Pei; Xu, Du-Juan; Huang, Can; Wang, Wei-Ping; Xu, Wen-Ke

    2014-06-01

    Astragaloside is a saponin widely used in traditional Chinese medicine and has been reported to be a potent multidrug resistance (MDR) reversal agent. The present study investigated the role of astragaloside Ⅳ (ASIV) in the regulation of P-glycoprotein (P-gp, encoded by the mdr1 gene) and its effect on the reversal of MDR. The activity of ASIV was evaluated using human hepatic cancer cells Bel-7402 and the corresponding 5-fluorouracil (5-FU) resistant cells Bel-7402/FU. ASIV (0.08 mg/ml) potentiated the cytotoxicity of 5-FU which was demonstrated using the MTT assay on Bel-7402/FU cells. ASIV reduced the expression of P-gp as was revealed by immunocytochemistry. Accumulation and efflux studies with the P-gp substrate, rhodamine 123 (Rh123), demonstrated that ASIV inhibited P-gp-mediated drug efflux. Furthermore, it was demonstrated that ASⅣ enhanced the drug accumulation of 5-FU using a high performance liquid chromatography (HPLC) assay for drug resistant cells. Furthermore, ASIV may downregulate the expression of P-gp, which was examined using western blot analysis and polymerase chain reaction. In conclusion, the results of the present study indicated that ASIV reverses the drug resistance of Bel-7402/FU cells by downregulating the expression of mdr1. ASIV may represent a potent modulator of P-gp-mediated MDR in hepatic cancer therapy. PMID:24676670

  5. Influences of "spasmolytic powder" on pgp expression of Coriaria Lactone-kindling drug-resistant epileptic rat model.

    Science.gov (United States)

    Chen, Lei; Feng, Peimin; Li, Yaohua; Zhou, Dong

    2013-09-01

    The earliest records of traditional Chinese medicine (TCM) prevention and treatment of epilepsy dated back to famous "Huang Di Nei Jing." TCM "spasmolytic powder" (equal-ratio compatibility of scorpion and centipede) is a famous prescription which was recognized as a useful add-on drug for refractory epilepsy in clinical observations. Multidrug resistance gene (mdr1) product Pgp overexpression in blood-brain barrier and blood-cerebrospinal fluid barrier is well recognized as the drug resistance mechanism of refractory epilepsy. Here, we established the drug-resistant epilepsy Sprague-Dawley rat model induced by Coriaria Lactone and treated these rats with topiramate and verapamil and low dose, middle dose, and high dose of spasmolytic powder by intragastric administration for 1 week. Electroencephalogram, real-time PCR, and immunohistochemistry were respectively used to detect epileptic discharge frequencies and amplitudes and expression of mdrl mRNA and Pgp on hippocampus and temporal lobe of rats. The results showed that the seizure decreases significantly in the high- and middle-dose groups of spasmolytic powder and topiramate group; in addition, mdr1 mRNA and Pgp expressions on hippocampus and temporal lobe of these drug intervention groups were significantly less than the model group (P < 0.05). These findings indicate that inhibition of intracephalic Pgp expression is possibly one of mechanisms of spasmolytic powder treating refractory epilepsy.

  6. Distinct alterations in ATP-binding cassette transporter expression in liver, kidney, small intestine, and brain in adjuvant-induced arthritic rats.

    Science.gov (United States)

    Kawase, Atsushi; Norikane, Sari; Okada, Ayaka; Adachi, Mamiko; Kato, Yukio; Iwaki, Masahiro

    2014-08-01

    Pathophysiological changes of infection or inflammation are associated with alterations in the production of numerous absorption, distribution, metabolism and excretion-related proteins. However, little information is available on the effects of inflammation on the expression levels and activities of ATP-binding cassette (ABC) transporters. We examined the effect of acute (on day 7) and chronic (on day 21) inflammation on the expression of ABC transporters in some major tissues in rat. Adjuvant-induced arthritis (AA) in rats was used as an animal model for inflammation. The mRNA levels of mdr1a and mdr1b encoding P-glycoprotein (P-gp) decreased significantly in livers of AA rats on day 21. Hepatic protein levels of P-gp, Mrp2, and Bcrp decreased significantly in membranes but not homogenates of AA rats after 7 days and after 21 days of treatment with adjuvant. Contrary to liver, protein levels of P-gp and Mrp2, but not Bcrp in kidney, increased significantly in membranes. The biliary excretion of rhodamine 123 was decreased in rats with chronic inflammation owing to decreases in efflux activities of P-gp. Our results showed that the expression of transporters in response to inflammation was organ dependent. In particular, hepatic and renal P-gp and Mrp2 exhibited opposite changes in membrane protein levels.

  7. Increased intestinal P-glycoprotein expression and activity with progression of diabetes and its modulation by epigallocatechin-3-gallate: Evidence from pharmacokinetic studies.

    Science.gov (United States)

    Dash, Ranjeet Prasad; Ellendula, Bhanuchander; Agarwal, Milee; Nivsarkar, Manish

    2015-11-15

    The aim of this study was to evaluate the change in the expression and the activity of intestinal P-glycoprotein (efflux transporter) with progression of diabetes in rats. Diabetes was induced in Wistar rats using a combination of low dose streptozotocin along with high fat diet. The expression of intestinal P-glycoprotein significantly increased (P≤0.05) with the progression of diabetes which was inferred from the mRNA analysis of mdr1a and mdr1b genes in the ileum segment of rat intestine. Furthermore, a significant increase (P≤0.05) in Na(+)-K(+) ATPase activity was observed in the ileum segment of rat intestine with the progression of diabetes. As a result of this, a significant decrease in the intestinal uptake and peroral bioavailability of the P-glycoprotein substrates (verapamil and atorvastatin) was observed along with the progression of diabetes as compared to normal animals. To address this problem of impaired drug uptake and bioavailability, a reported P-glycoprotein inhibitor, epigallocatechin-3-gallate, was experimentally evaluated. The treatment with epigallocatechin-3-gallate resulted in significant reduction in the expression and activity of P-glycoprotein and subsequent improvement in the intestinal uptake and peroral bioavailability of both verapamil and atorvastatin in normal as well as in diabetic animals. The findings of this study rationalised the use and established the mechanism of action of epigallocatechin-3-gallate to overcome P-glycoprotein mediated drug efflux and will also be helpful in therapeutic drug monitoring in diabetes.

  8. Tyrosine kinase inhibitors influence ABCG2 expression in EGFR-positive MDCK BCRP cells via the PI3K/Akt signaling pathway.

    Science.gov (United States)

    Pick, Anne; Wiese, Michael

    2012-04-01

    Multidrug resistance observed in cancer chemotherapy is commonly attributed to overexpression of efflux transporter proteins. These proteins act as ATP-dependent drug efflux pumps, actively extruding chemotherapeutic agents from cells and causing a decrease in intracellular drug accumulation. Besides the well-recognized role of P-glycoprotein (P-gp, ABCB1), the breast cancer resistance protein (BCRP, ABCG2) is becoming increasingly accepted as playing an important role in multidrug resistance. In contrast to P-glycoprotein, only a few inhibitors of ABCG2 are known. According to the literature, tyrosine kinase inhibitors (TKIs) can be considered to be broad-spectrum inhibitors, interacting with ABCB1, ABCC1 and ABCG2. Here, we investigated seven different TKIs, gefitinib, erlotinib, AG1478, PD158780, PD153035, nilotinib and imatinib, for their potential to restore ABCG2 sensitivity to cells. Furthermore, we analyzed the alteration of ABCG2 expression caused by TKIs and demonstrated that EGFR inhibitors such as gefitinib and PD158780 reduced both total and surface expression of ABCG2 in EGRF-positive MDCK BCRP cells by interaction with the PI3K/Akt signaling pathway. The reduced ABCG2 content led to an increased effect of XR9577, a well-known ABCG2 modulator, lowering the concentration required for half maximal inhibition. On the other hand, BCR-ABL inhibitors had no influence on ABCG2 expression and modulator activity. Interestingly, a combination of an EGFR inhibitor with the PI3K/Akt inhibitor LY294002 led to a significant reduction of ABCG2 expression at low concentrations of the drugs. Based on our results, we assume that EGFR exerts a post-transcriptional enhancing effect on ABCG2 expression via the PI3K/Akt signaling pathway, which can be attenuated by EGFR inhibitors. Blocking the key signaling pathway regulating ABCG2 expression with EGFR inhibitors, combined with the inhibition of ABCG2 with potent modulators might be a promising approach to circumvent MDR

  9. 1α,25-Dihydroxyvitamin D3-Liganded Vitamin D Receptor Increases Expression and Transport Activity of P-glycoprotein in Isolated Rat Brain Capillaries and Human and Rat Brain Microvessel Endothelial Cells

    OpenAIRE

    Durk, Matthew R.; Chan, Gary N.Y.; Campos, Christopher R.; Peart, John C.; Chow, Edwin C.Y.; Lee, Eason; Cannon, Ronald E.; Bendayan, Reina; Miller, David S.; Pang, K. Sandy

    2012-01-01

    MDR1/P-gp induction by the vitamin D receptor (VDR) was investigated in isolated rat brain capillaries and rat (RBE4) and human (hCMEC/D3) brain microvessel endothelial cell lines. Incubation of isolated rat brain capillaries with 10 nM of the VDR ligand, 1α,25-dihydroxyvitamin D3 [1,25(OH)2D3] for 4 h increased P-gp protein expression (4-fold). Incubation with 1,25(OH)2D3 for 4 or 24 h increased P-gp transport activity (specific luminal accumulation of NBD-CSA, the fluorescent P-gp substrate...

  10. P-glycoprotein is expressed and causes resistance to chemotherapy in EBV-positive T-cell lymphoproliferative diseases.

    Science.gov (United States)

    Yoshimori, Mayumi; Takada, Honami; Imadome, Ken-Ichi; Kurata, Morito; Yamamoto, Kouhei; Koyama, Takatoshi; Shimizu, Norio; Fujiwara, Shigeyoshi; Miura, Osamu; Arai, Ayako

    2015-10-01

    Epstein-Barr virus-positive T-cell lymphoproliferative diseases (EBV-T-LPDs) are rare lymphomas with poor prognosis. Although chemotherapeutic strategies such as CHOP have been often selected, they have exhibited only limited efficacy. To clarify the mechanism of chemoresistance, we examined P-glycoprotein (P-gp) expression. P-gp acts as an energy-dependent efflux pump that excretes drugs from the cytoplasm, resulting in low-intracellular drug concentrations and poor sensitivity to chemotherapy. We examined P-gp expression in EBV-positive cells by immunohistochemistry staining in three patients of EBV-T-LPDs and the expression was detected in all patients. We also examined mdr1 mRNA expression by reverse-transcriptase polymerase-chain reaction (RT-PCR) in EBV-positive tumor cells from these patients and additional three patients. The expression was detected in all examined patients. In five EBV-T-LPDs patients, P-gp function was detected by Rhodamine-123 efflux assay in these cells. The efflux was inhibited by treatment with a P-gp inhibitor, cyclosporine A (CsA). We also examined and detected P-gp expression in EBV-positive T-cell lines SNT8 and SNT16 established from EBV-T-LPDs patients, by RT-PCR and western blotting. The function was also detected by Rhodamine-123 efflux in these cell lines. Inhibition and knock down of P-gp by CsA and siRNA, respectively, enhanced etoposide- and doxorubicin-induced cell death in the EBV-positive T-cell lines. Finally, we infected the T-cell line MOLT4 with EBV, and found that mdr1 mRNA expression and Rhodamine 123 efflux were upregulated after infection. These results indicated that enhanced P-gp expression contributed to the chemoresistance of EBV-T-LPDs.

  11. P-glycoprotein is expressed and causes resistance to chemotherapy in EBV-positive T-cell lymphoproliferative diseases

    International Nuclear Information System (INIS)

    Epstein–Barr virus-positive T-cell lymphoproliferative diseases (EBV-T-LPDs) are rare lymphomas with poor prognosis. Although chemotherapeutic strategies such as CHOP have been often selected, they have exhibited only limited efficacy. To clarify the mechanism of chemoresistance, we examined P-glycoprotein (P-gp) expression. P-gp acts as an energy-dependent efflux pump that excretes drugs from the cytoplasm, resulting in low-intracellular drug concentrations and poor sensitivity to chemotherapy. We examined P-gp expression in EBV-positive cells by immunohistochemistry staining in three patients of EBV-T-LPDs and the expression was detected in all patients. We also examined mdr1 mRNA expression by reverse-transcriptase polymerase-chain reaction (RT-PCR) in EBV-positive tumor cells from these patients and additional three patients. The expression was detected in all examined patients. In five EBV-T-LPDs patients, P-gp function was detected by Rhodamine-123 efflux assay in these cells. The efflux was inhibited by treatment with a P-gp inhibitor, cyclosporine A (CsA). We also examined and detected P-gp expression in EBV-positive T-cell lines SNT8 and SNT16 established from EBV-T-LPDs patients, by RT-PCR and western blotting. The function was also detected by Rhodamine-123 efflux in these cell lines. Inhibition and knock down of P-gp by CsA and siRNA, respectively, enhanced etoposide- and doxorubicin-induced cell death in the EBV-positive T-cell lines. Finally, we infected the T-cell line MOLT4 with EBV, and found that mdr1 mRNA expression and Rhodamine 123 efflux were upregulated after infection. These results indicated that enhanced P-gp expression contributed to the chemoresistance of EBV-T-LPDs

  12. HIV-1 Alters Intestinal Expression of Drug Transporters and Metabolic Enzymes: Implications for Antiretroviral Drug Disposition.

    Science.gov (United States)

    Kis, Olena; Sankaran-Walters, Sumathi; Hoque, M Tozammel; Walmsley, Sharon L; Dandekar, Satya; Bendayan, Reina

    2016-05-01

    This study investigated the effects of HIV-1 infection and antiretroviral therapy (ART) on the expression of intestinal drug efflux transporters, i.e., P-glycoprotein (Pgp), multidrug resistance-associated proteins (MRPs), and breast cancer resistance protein (BCRP), and metabolic enzymes, such as cytochrome P450s (CYPs), in the human upper intestinal tract. Intestinal biopsy specimens were obtained from HIV-negative healthy volunteers, ART-naive HIV-positive (HIV(+)) subjects, and HIV(+) subjects receiving ART (10 in each group). Intestinal tissue expression of drug transporters and metabolic enzymes was examined by microarray, real-time quantitative reverse transcription-PCR (qPCR), and immunohistochemistry analyses. Microarray analysis demonstrated significantly lower expression of CYP3A4 and ABCC2/MRP2 in the HIV(+) ART-naive group than in uninfected subjects. qPCR analysis confirmed significantly lower expression of ABCC2/MRP2 in ART-naive subjects than in the control group, while CYP3A4 and ABCG2/BCRP showed a trend toward decreased expression. Protein expression of MRP2 and BCRP was also significantly lower in the HIV(+) naive group than in the control group and was partially restored to baseline levels in HIV(+) subjects receiving ART. In contrast, gene and protein expression of ABCB1/Pgp was significantly increased in HIV(+) subjects on ART relative to HIV(+) ART-naive subjects. These data demonstrate that the expression of drug-metabolizing enzymes and efflux transporters is significantly altered in therapy-naive HIV(+) subjects and in those receiving ART. Since CYP3A4, Pgp, MRPs, and BCRP metabolize or transport many antiretroviral drugs, their altered expression with HIV infection may negatively impact drug pharmacokinetics in HIV(+) subjects. This has clinical implications when using data from healthy volunteers to guide ART. PMID:26902756

  13. Differential Gene Expression across Breed and Sex in Commercial Pigs Administered Fenbendazole and Flunixin Meglumine.

    Directory of Open Access Journals (Sweden)

    Jeremy T Howard

    Full Text Available Characterizing the variability in transcript levels across breeds and sex in swine for genes that play a role in drug metabolism may shed light on breed and sex differences in drug metabolism. The objective of the study is to determine if there is heterogeneity between swine breeds and sex in transcript levels for genes previously shown to play a role in drug metabolism for animals administered flunixin meglumine or fenbendazole. Crossbred nursery female and castrated male pigs (n = 169 spread across 5 groups were utilized. Sires (n = 15 of the pigs were purebred Duroc, Landrace, Yorkshire or Hampshire boars mated to a common sow population. Animals were randomly placed into the following treatments: no drug (control, flunixin meglumine, or fenbendazole. One hour after the second dosing, animals were sacrificed and liver samples collected. Quantitative Real-Time PCR was used to measure liver gene expression of the following genes: SULT1A1, ABCB1, CYP1A2, CYP2E1, CYP3A22 and CYP3A29. The control animals were used to investigate baseline transcript level differences across breed and sex. Post drug administration transcript differences across breed and sex were investigated by comparing animals administered the drug to the controls. Contrasts to determine fold change were constructed from a model that included fixed and random effects within each drug. Significant (P-value <0.007 basal transcript differences were found across breeds for SULT1A1, CYP3A29 and CYP3A22. Across drugs, significant (P-value <0.0038 transcript differences existed between animals given a drug and controls across breeds and sex for ABCB1, PS and CYP1A2. Significant (P <0.0038 transcript differences across breeds were found for CYP2E1 and SULT1A1 for flunixin meglumine and fenbendazole, respectively. The current analysis found transcript level differences across swine breeds and sex for multiple genes, which provides greater insight into the relationship between flunixin

  14. Differential Gene Expression across Breed and Sex in Commercial Pigs Administered Fenbendazole and Flunixin Meglumine

    Science.gov (United States)

    Howard, Jeremy T.; O’Nan, Audrey T.; Maltecca, Christian; Baynes, Ronald E.; Ashwell, Melissa S.

    2015-01-01

    Characterizing the variability in transcript levels across breeds and sex in swine for genes that play a role in drug metabolism may shed light on breed and sex differences in drug metabolism. The objective of the study is to determine if there is heterogeneity between swine breeds and sex in transcript levels for genes previously shown to play a role in drug metabolism for animals administered flunixin meglumine or fenbendazole. Crossbred nursery female and castrated male pigs (n = 169) spread across 5 groups were utilized. Sires (n = 15) of the pigs were purebred Duroc, Landrace, Yorkshire or Hampshire boars mated to a common sow population. Animals were randomly placed into the following treatments: no drug (control), flunixin meglumine, or fenbendazole. One hour after the second dosing, animals were sacrificed and liver samples collected. Quantitative Real-Time PCR was used to measure liver gene expression of the following genes: SULT1A1, ABCB1, CYP1A2, CYP2E1, CYP3A22 and CYP3A29. The control animals were used to investigate baseline transcript level differences across breed and sex. Post drug administration transcript differences across breed and sex were investigated by comparing animals administered the drug to the controls. Contrasts to determine fold change were constructed from a model that included fixed and random effects within each drug. Significant (P-value <0.007) basal transcript differences were found across breeds for SULT1A1, CYP3A29 and CYP3A22. Across drugs, significant (P-value <0.0038) transcript differences existed between animals given a drug and controls across breeds and sex for ABCB1, PS and CYP1A2. Significant (P <0.0038) transcript differences across breeds were found for CYP2E1 and SULT1A1 for flunixin meglumine and fenbendazole, respectively. The current analysis found transcript level differences across swine breeds and sex for multiple genes, which provides greater insight into the relationship between flunixin meglumine and

  15. THE CORRELATION BETWEEN THE EXPRESSION OF MULTIDRUG RESISTANCE RELATED GENE AND CELL APOPTOSIS AND CLINICAL SIGNIFICANCE IN NON-SMALL CELL LUNG CANCER

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective: To explore the correlation and clinical significance between expression of MDR (multidrug resistance) related gene MRP, MDR1, C-erbB-2 and cell apoptosis in non-small cell lung cancer (NSCLC). Methods: RT-PCR, Immunohistochemistry were used to examine the expression of mRNA and protein in the MDR and apoptosis related gene. Apoptosis cells were assayed by Terminal deoxynucleotidyl transferase (TdT)- mediated biotin dUTP nick end-labeling (TUNEL). Results: The positive rates of MRP, MDR1, C-erbB-2, bc1-2, C-myc mRNA in 63 cases NSCLC were 81.0% (51/63), 38.1%(24/63), 47.6%(30/63), 65.1%(41/63), 76.2%(48/63) respectively. Their levels were higher than those of corresponding proteins (74.6%, 34.9%, 46.0%, 61.9%, 71.4%, respectively). The significant association was found between the mRNA level and the protein expression (r =+0.764, P<0.02). The C-myc expression in 2 cases adjacent and benign lung tissue were light positive, and another 3 cases were negative. The positive correlation were demonstrated between C-myc and C-erbB-2 (r=+0.547, p=0.001) as well as bcl-2 and C-erbB-2 (r =+0.486, p=0.023) in NSCLC. There is no any correlation among bcl-2, C-myc and MRP or MDR1. There exists inverse correlation between apoptotic index and bcl-2 (r = -0.587, p = 0.017), and no any correlation among apoptotic index and MRP com or MDR1 or C-erbB-2 or C-myc. The average apoptotic index were higher in the effective chemotherapy group (27.2± 2.1, 30.5± 1.8) than that in the non-effective chemotherapy group (9.4± 1.3, 12.6± 2.4) with adenocarcinoma and squamous cell carcinoma (p =0.01, p=0.004). The positive rates of bcl-2, MRP, C-erbB-2 expression in the effective chemotherapy group (31.8%, 40.9%, 22.7%, respectively) were lower than those in the non-effective chemotherapy group (77.4%, 90.3%, 67.7%, respectively) (p=0.036, p=0.012, p=0.01), but MDR1 and C-myc expression have no any significant difference (p=0.067, p=0.282). The median survival time in the patients

  16. Regulation of hypoxia inducible factor-1α expression by the alteration of redox status in HepG2 cells

    Directory of Open Access Journals (Sweden)

    Zhang Wu-kui

    2011-05-01

    Full Text Available Abstract Hypoxia inducible factor-1 (HIF-1 has been considered as a critical transcriptional factor in response to hypoxia. It can increase P-glycoprotein (P-Gp thus generating the resistant effect to chemotherapy. At present, the mechanism regulating HIF-1α is still not fully clear in hypoxic tumor cells. Intracellular redox status is closely correlated with hypoxic micro-environment, so we investigate whether alterations in the cellular redox status lead to the changes of HIF-1α expression. HepG2 cells were exposed to Buthionine sulphoximine (BSO for 12 h prior to hypoxia treatment. The level of HIF-1α expression was measured by Western blot and immunocytochemistry assays. Reduce glutathione (GSH concentrations in hypoxic cells were determined using glutathione reductase/5,5'-dithiobis-(2-nitrob-enzoic acid (DTNB recycling assay. To further confirm the effect of intracellular redox status on HIF-1α expression, N-acetylcysteine (NAC was added to culture cells for 8 h before the hypoxia treatment. The levels of multidrug resistance gene-1 (MDR-1 and erythropoietin (EPO mRNA targeted by HIF-1α in hypoxic cells were further determined with RT-PCR, and then the expression of P-Gp protein was observed by Western blotting. The results showed that BSO pretreatment down-regulated HIF-1α and the effect was concentration-dependent, on the other hand, the increases of intracellular GSH contents by NAC could partly elevate the levels of HIF-1α expression. The levels of P-Gp (MDR-1 and EPO were concomitant with the trend of HIF-1α expression. Therefore, our data indicate that the changes of redox status in hypoxic cells may regulate HIF-1α expression and provide valuable information on tumor chemotherapy.

  17. Resistant mechanisms of anthracyclines--pirarubicin might partly break through the P-glycoprotein-mediated drug-resistance of human breast cancer tissues.

    Science.gov (United States)

    Kubota, T; Furukawa, T; Tanino, H; Suto, A; Otan, Y; Watanabe, M; Ikeda, T; Kitajima, M

    2001-01-01

    Juliano and Ling initially reported the expression of a 170 kDa glycoprotein in the membrane of Chinese hamster ovarian cells in 1976, and named this glycoprotein P-glycoprotein (P-gp) based on its predicted role of causing "permeability" of the cell membrane. After much research on anthracycline-resistance, this P-gp was finally characterized as a multidrug-resistant protein coded by the mdr1 gene. Multidrug resistance associated protein (MRP) was initially cloned from H69AR, a human small cell-lung carcinoma cell line which is resistant to doxorubicin (DXR) but does not express P-gp. MRP also excretes substrates through the cell membrane using energy from ATP catabolism. The substrate of MRP is conjugated with glutathione before active efflux from cell membrane. Recently, membrane transporter proteins were re-categorized as members of "ATP-Binding Cassette transporter"(ABC-transporter) superfamily, as shown at http://www.med.rug.nl/mdl/humanabc.htm and http://www.gene.ucl.ac.uk/nomenclature/genefamily/abc.html. A total of ABC transporters have been defined, and MDR1 and multidrug resistance associated protein 1 (MRP1) were reclassified as ABCB1 and ABCC1, respectively. Their associated superfamilies include 11 and 13 other protein, in addition to ABCB and ABCC, respectively. Lung resistance-related protein (LRP) is not a member of the superfamily of ABC transporter proteins, because it shows nuclear membrane expression and transports substrate between nucleus and cytoplasm. LRP was initially cloned from a non-small cell lung carcinoma cell line, SW1573/2R120 which is resistant to DXR, vincristine, etoposide and gramicidin D and does not express P-gp. The mechanisms of resistance remains unclear, and why some resistant cell lines express P-gp and others express MRP and/or LRP is likewise unclear. PMID:11791127

  18. Expression of Drug-Resistant Factor Genes in Hepatocellular Carcinoma Patients Undergoing Chemotherapy with Platinum Complex by Arterial Infusion

    Directory of Open Access Journals (Sweden)

    Shiro Ueda

    2010-09-01

    Full Text Available This study investigated gene expression of drug resistance factors in biopsy tissue samples from hepatocellular carcinoma (HCC patients undergoing chemotherapy by platinum complex. Liver biopsy was performed to collect tissue from the tumor site (T and the non-tumor site (NT prior to the start of treatment. For drug-resistant factors, drug excretion transporters cMOAT and MDR-1, intracellular metal binding protein MT2, DNA repair enzyme ERCC-l and inter-nucleic cell transport protein MVP, were investigated. The comparison of the expression between T and NT indicated a significant decrease of MT2 and MDR-1 in T while a significant increase in ERCC-1 was noted in T. Further, expression was compared between the response cases and non-response cases using the ratios of expression in T to those in NT. The response rate was significantly low in the high expression group when the cutoff value of cMOAT and MT2 was set at 1.5 and 1.0, respectively. Furthermore, when the patients were classified into A group (cMOAT ≧ 1.5 or MT2 ≧ 1.0 and B group (cMOAT < 1.5 and MT2 < 1.0, the response rate of A group was significantly lower than B group when we combined the cutoff values of cMOAT and MT2. It is considered possible to estimate the therapeutic effect of platinum complex at a high probability by combining the expression condition of these two genes.

  19. Inhibition of Viability, Proliferation, Cytokines Secretion, Surface Antigen Expression, and Adipogenic and Osteogenic Differentiation of Adipose-Derived Stem Cells by Seven-Day Exposure to 0.5 T Static Magnetic Fields

    Directory of Open Access Journals (Sweden)

    Jian Wang

    2016-01-01

    Full Text Available After seven-day exposure to 0.5-Tesla Static Magnetic Field (SMF, Adipose-derived Stem Cells (ASCs and those labeled by superparamagnetic iron oxide (SPIO nanoparticles were examined for viability by methyl thiazol tetrazolium (MTT assay, proliferation by cell counting and bromodeoxyuridine (BrdU incorporation, DNA integrity by single cell gel electrophoresis, surface antigen by flow cytometry analysis, and the expression of cytokines and genetic markers by reverse transcription-PCR and underwent adipogenic and osteogenic differentiation assessed by quantifying related specific genes expression. The SMF slightly reduced cell viability and proliferation and inhibited the expression of CD49d, CD54, and CD73 but did not damage DNA integrity. The SMF slightly downregulated the expression of cytokines including Vascular Endothelial Growth Factor (VEGF, Insulin-like Growth Factor-1 (IGF-1, Transforming Growth Factor Beta 1 (TGF-β1, genetic markers comprising Stem Cell Antigen-1 (Sca1, Octamer-4 (Oct-4, ATP-binding Cassette Subfamily B Member 1 (ABCB1, adipogenic marker genes containing Lipoprotein Lipase (LPL, Peroxisome Proliferator-Activated Receptor Gamma (PPAR-γ, and osteogenic marker genes including Secreted Phosphor-protein 1 (SPP1 and Osterix (OSX. Exposure to 0.5 T SMF for seven days inhibited viability, proliferation, surface antigen expression, cytokine secretion, stem cell genetic marker expression, and adipogenic and osteogenic differentiation but did not affect the DNA integrity in ASCs with or without SPIO labeling.

  20. Staphylococcus aureus and Lipopolysaccharide Modulate Gene Expressions of Drug Transporters in Mouse Mammary Epithelial Cells Correlation to Inflammatory Biomarkers

    Science.gov (United States)

    Yagdiran, Yagmur; Tallkvist, Jonas; Artursson, Karin

    2016-01-01

    Inflammation in the mammary gland (mastitis) is the most common disease in dairy herds worldwide, often caused by the pathogens Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Little is known about the effects of mastitis on drug transporters and the impact on transporter-mediated excretion of drugs into milk. We used murine mammary epithelial HC11 cells, after lactogenic differentiation into a secreting phenotype, and studied gene expressions of ABC- and SLC- transporters after treatment of cells with S. aureus and lipopolysaccharide, an endotoxin secreted by E. coli. The studied transporters were Bcrp, Mdr1, Mrp1, Oatp1a5, Octn1 and Oct1. In addition, Csn2, the gene encoding β-casein, was analyzed. As biomarkers of the inflammatory response, gene expressions of the cytokines Il6 and Tnfα and the chemokine Cxcl2 were determined. Our results show that S. aureus and LPS treatment of cells, at non-cytotoxic concentrations, induced an up-regulation of Mdr1 and of the inflammatory biomarkers, except that Tnfα was not affected by lipopolysaccharide. By simple regression analysis we could demonstrate statistically significant positive correlations between each of the transporters with each of the inflammatory biomarkers in cells treated with S. aureus. The coefficients of determination (R2) were 0.7–0.9 for all but one correlation. After treatment of cells with lipopolysaccharide, statistically significant correlations were only found between Mdr1 and the two parameters Cxcl2 and Il6. The expression of Csn2 was up-regulated in cells treated with S. aureus, indicating that the secretory function of the cells was not impaired. The strong correlation in gene expressions between transporters and inflammatory biomarkers may suggest a co-regulation and that the transporters have a role in the transport of cytokines and chemokines. Our results demonstrate that transporters in mammary cells can be affected by infection, which may have an impact on

  1. Optimization of irinotecan chronotherapy with P-glycoprotein inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Filipski, Elisabeth; Berland, Elodie [INSERM, U776 “Rythmes biologiques et cancers”, CAMPUS CNRS, 7 rue Guy Môquet, F-94801 Villejuif (France); Univ Paris-Sud, UMR-S0776, Orsay F-91405 (France); Ozturk, Narin [INSERM, U776 “Rythmes biologiques et cancers”, CAMPUS CNRS, 7 rue Guy Môquet, F-94801 Villejuif (France); Univ Paris-Sud, UMR-S0776, Orsay F-91405 (France); Istanbul University Faculty of Pharmacy, Department of Pharmacology, Beyazit TR-34116, Istanbul (Turkey); Guettier, Catherine [Assistance Publique-Hôpitaux de Paris, Unité de Chronothérapie, Département de Cancérologie, Hôpital Paul Brousse, Villejuif F-94807 (France); Horst, Gijsbertus T.J. van der [Department of Genetics, Erasmus University Medical Center, 3000 CA Rotterdam (Netherlands); Lévi, Francis [INSERM, U776 “Rythmes biologiques et cancers”, CAMPUS CNRS, 7 rue Guy Môquet, F-94801 Villejuif (France); Univ Paris-Sud, UMR-S0776, Orsay F-91405 (France); Assistance Publique-Hôpitaux de Paris, Unité de Chronothérapie, Département de Cancérologie, Hôpital Paul Brousse, Villejuif F-94807 (France); and others

    2014-02-01

    The relevance of P-glycoprotein (P-gp) for irinotecan chronopharmacology was investigated in female B6D2F{sub 1} mice. A three-fold 24 h change in the mRNA expression of Abcb1b was demonstrated in ileum mucosa, with a maximum at Zeitgeber Time (ZT) 15 (p < 0.001). No rhythm was found for abcb1a in ileum mucosa, or for Abcb1a/b in Glasgow osteosarcoma (GOS), a mouse tumor cell line moderately sensitive to irinotecan. Non-tumor-bearing mice received irinotecan (50 mg/kg/day i.v. × 4 days) as a single agent or combined with P-gp inhibitor PSC833 (6.25 mg/kg/day i.p. × 4 days) at ZT3 or ZT15, respectively corresponding to the worst or the best irinotecan tolerability. Endpoints involved survival, body weight change and hematologic toxicity. Antitumor efficacy was studied in GOS-bearing mice receiving irinotecan (25, 30 or 40 mg/kg/day × 4 days) and +/− PSC833 at ZT3 or ZT15, with survival, body weight change, and tumor growth inhibition as endpoints. Non-tumor bearing mice lost an average of 17% or 9% of their body weight according to irinotecan administration at ZT3 or ZT15 respectively (p < 0.001). Dosing at ZT15 rather than ZT3 reduced mean leucopenia (9% vs 53%; p < 0.001). PSC833 aggravated irinotecan lethal toxicity from 4 to ∼ 60%. In tumor-bearing mice, body weight loss was ∼ halved in the mice on irinotecan or irinotecan–PSC833 combination at ZT15 as compared to ZT3 (p < 0.001). PSC833–irinotecan at ZT15 increased tumor inhibition by ∼ 40% as compared to irinotecan only at ZT15. In conclusion, P-gp was an important determinant of the circadian balance between toxicity and efficacy of irinotecan. - Highlights: • Irinotecan chronotolerance and chronoefficacy change as drug was applied with PSC833. • P-glycoprotein is an important player of the toxicity and efficacy of irinotecan. • Timing should be considered if chemotherapy is performed with a MDR1 inhibitor.

  2. Hepatic drug transporters and nuclear receptors: Regulation by therapeutic agents

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The canalicular membrane represents the excretory pole of hepatocytes. Bile is an important route of elimina-tion of potentially toxic endo- and xenobiotics (including drugs and toxins), mediated by the major canalicular transporters: multidrug resistance protein 1 (MDR1, ABCB1), also known as P-glycoprotein, multidrug re-sistance-associated protein 2 (MRP2, ABCC2), and the breast cancer resistance protein (BCRP, ABCG2). Their activities depend on regulation of expression and proper localization at the canalicular membrane, as regulated by transcriptional and post-transcriptional events, re-spectively. At transcriptional level, specific nuclear re-ceptors (NR)s modulated by ligands, co-activators and co-repressors, mediate the physiological requirements of these transporters. This complex system is also re-sponsible for alterations occurring in specific liver pa-thologies. We briefly describe the major Class Ⅱ NRs, pregnane X receptor (PXR) and constitutive androstane receptor (CAR), and their role in regulating expression of multidrug resistance proteins. Several therapeutic agents regulate the expression of relevant drug trans-porters through activation/inactivation of these NRs. We provide some representative examples of the action of therapeutic agents modulating liver drug transporters, which in addition, involve CAR or PXR as mediators.

  3. Expression of the bitter receptor T2R38 in pancreatic cancer: localization in lipid droplets and activation by a bacteria-derived quorum-sensing molecule

    Science.gov (United States)

    Gaida, Matthias M.; Mayer, Christine; Dapunt, Ulrike; Stegmaier, Sabine; Schirmacher, Peter; Wabnitz, Guido H.; Hänsch, G. Maria

    2016-01-01

    T2R38 belongs to the family of bitter receptors and was initially detected in cells of the oral cavity. We now describe expression of T2R38 in tumor cells in patients with pancreatic cancer and in tumor-derived cell lines. T2R38 is localized predominantly intracellular in association with lipid droplets, particularly with the lipid droplet membrane. The receptor can be activated by the bona fide ligand for T2R38, phenylthiourea (PTU), and by N-acetyl-dodecanoyl homoserine (AHL-12), a quorum sensing molecule of Pseudomonas aeruginosa, the latter is the only known natural ligand for T2R38. In response to PTU or AHL-12, key transcription factors are activated including phosphorylation of the MAP kinases p38 and ERK1/2, and upregulation of NFATc1. Moreover, we found increased expression of the multi-drug resistance protein 1 (also known as ABCB1), a transmembrane transporter molecule, participating in shuttling of a plethora of drugs, such as chemotherapeutics or antibiotics. In conclusion, our data indicate a new, additional function of the taste receptor T2R38 beyond sensing ‘bitter’. Moreover, because T2R38 can be stimulated by a bacteria-derived signaling molecule the receptor could link microbiota and cancer. PMID:26862855

  4. P-glycoprotein and its inducible expression in three bivalve species after exposure to Prorocentrum lima.

    Science.gov (United States)

    Huang, Lu; Liu, Su-Li; Zheng, Jian-Wei; Li, Hong-Ye; Liu, Jie-Sheng; Yang, Wei-Dong

    2015-12-01

    P-glycoprotein (P-gp or ABCB1) belongs to the family of ATP-binding cassette (ABC) transporters responsible for multixenobiotic resistance (MXR) in aquatic organisms. To provide more information of P-gp in shellfish, in this study, complete cDNA of P-gp in three bivalve species including Ruditapes philippinarum, Scapharca subcrenata and Tegillarca granosa were cloned and its expressions in gill, digestive gland, adductor muscle and mantle of the three bivalves were detected after exposure to Prorocentrum lima, a toxogenic dinoflagellate. The complete sequences of R. philippinarum, S. subcrenata and T. granosa P-gp showed high homology with MDR/P-gp/ABCB proteins from other species, having a typical sequence organization as full transporters from the ABCB family. Phylogenetic analyses revealed that the amino acid sequences of P-gp from S. subcrenata and T. granosa had a closest relationship, forming an independent branch, then grouping into the other branch with Mytilus californianus, Mytilus galloprovincialis and Crassostrea gigas. However, P-gp sequences from R. philippinarum were more similar to the homologs from the more distantly related Aplysia californica than to homologs from S. subcrenata and T. granosa, suggesting that bivalves P-gp might have different paralogs. P-glycoprotein expressed in all detected tissues but there were large differences between them. After exposure to P. lima, the expression of P-gp changed in the four tissues in varying degrees within the same species and between different species, but the changes in mRNA and protein level were not always synchronous.

  5. Construction and expression of retroviruses encoding dual drug resistance genes in human umbilical cord blood CD34+ cells

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A series of retroviral vectors encoding human mdr1 gene alone as well as in combination with either human mgmt gene or human mutant Ser31-dhfr gene are engineered. The resultant retroviruses are used to transduce human umbilical cord blood CD34+ cells. It has been shown that expression of dual drug resistance genes in transduced cells confers a broad range of resistance to both kinds of corresponding drugs. These data suggest a rationale for the use of such double chemoresistance gene constructs in an in vivo model in which transduced hematopoietic cells will acquire multiple protection against the cytotoxic side effects of combination chemotherapy and may have future application in chemoprotection of normal tissues, thus killing tumor cells more effectively.

  6. Role of ABC and Solute Carrier Transporters in the Placental Transport of Lamivudine.

    Science.gov (United States)

    Ceckova, Martina; Reznicek, Josef; Ptackova, Zuzana; Cerveny, Lukas; Müller, Fabian; Kacerovsky, Marian; Fromm, Martin F; Glazier, Jocelyn D; Staud, Frantisek

    2016-09-01

    Lamivudine is one of the antiretroviral drugs of choice for the prevention of mother-to-child transmission (MTCT) in HIV-positive women. In this study, we investigated the relevance of drug efflux transporters P-glycoprotein (P-gp) (MDR1 [ABCB1]), BCRP (ABCG2), MRP2 (ABCC2), and MATE1 (SLC47A1) for the transmembrane transport and transplacental transfer of lamivudine. We employed in vitro accumulation and transport experiments on MDCK cells overexpressing drug efflux transporters, in situ-perfused rat term placenta, and vesicular uptake in microvillous plasma membrane (MVM) vesicles isolated from human term placenta. MATE1 significantly accelerated lamivudine transport in MATE1-expressing MDCK cells, whereas no transporter-driven efflux of lamivudine was observed in MDCK-MDR1, MDCK-MRP2, and MDCK-BCRP monolayers. MATE1-mediated efflux of lamivudine appeared to be a low-affinity process (apparent Km of 4.21 mM and Vmax of 5.18 nmol/mg protein/min in MDCK-MATE1 cells). Consistent with in vitro transport studies, the transplacental clearance of lamivudine was not affected by P-gp, BCRP, or MRP2. However, lamivudine transfer across dually perfused rat placenta and the uptake of lamivudine into human placental MVM vesicles revealed pH dependency, indicating possible involvement of MATE1 in the fetal-to-maternal efflux of the drug. To conclude, placental transport of lamivudine does not seem to be affected by P-gp, MRP2, or BCRP, but a pH-dependent mechanism mediates transport of lamivudine in the fetal-to-maternal direction. We suggest that MATE1 might be, at least partly, responsible for this transport. PMID:27401571

  7. Drug resistance is conferred on the model yeast Saccharomyces cerevisiae by expression of full-length melanoma-associated human ATP-binding cassette transporter ABCB5.

    Science.gov (United States)

    Keniya, Mikhail V; Holmes, Ann R; Niimi, Masakazu; Lamping, Erwin; Gillet, Jean-Pierre; Gottesman, Michael M; Cannon, Richard D

    2014-10-01

    ABCB5, an ATP-binding cassette (ABC) transporter, is highly expressed in melanoma cells, and may contribute to the extreme resistance of melanomas to chemotherapy by efflux of anti-cancer drugs. Our goal was to determine whether we could functionally express human ABCB5 in the model yeast Saccharomyces cerevisiae, in order to demonstrate an efflux function for ABCB5 in the absence of background pump activity from other human transporters. Heterologous expression would also facilitate drug discovery for this important target. DNAs encoding ABCB5 sequences were cloned into the chromosomal PDR5 locus of a S. cerevisiae strain in which seven endogenous ABC transporters have been deleted. Protein expression in the yeast cells was monitored by immunodetection using both a specific anti-ABCB5 antibody and a cross-reactive anti-ABCB1 antibody. ABCB5 function in recombinant yeast cells was measured by determining whether the cells possessed increased resistance to known pump substrates, compared to the host yeast strain, in assays of yeast growth. Three ABCB5 constructs were made in yeast. One was derived from the ABCB5-β mRNA, which is highly expressed in human tissues but is a truncation of a canonical full-size ABC transporter. Two constructs contained full-length ABCB5 sequences: either a native sequence from cDNA or a synthetic sequence codon-harmonized for S. cerevisiae. Expression of all three constructs in yeast was confirmed by immunodetection. Expression of the codon-harmonized full-length ABCB5 DNA conferred increased resistance, relative to the host yeast strain, to the putative substrates rhodamine 123, daunorubicin, tetramethylrhodamine, FK506, or clorgyline. We conclude that full-length ABCB5 can be functionally expressed in S. cerevisiae and confers drug resistance.

  8. mRNA levels of related Abcb genes change opposite to each other upon histone deacetylase inhibition in drug-resistant rat hepatoma cells.

    Directory of Open Access Journals (Sweden)

    Adám Sike

    Full Text Available The multidrug-resistant phenotype of tumor cells is acquired via an increased capability of drug efflux by ABC transporters and causes serious problems in cancer treatment. With the aim to uncover whether changes induced by epigenetic mechanisms in the expression level of drug transporter genes correlates with changes in the drug resistance phenotypes of resistant cells, we studied the expression of drug transporters in rat hepatoma cell lines. We found that of the three major rat ABC transporter genes Abcb1a, Abcb1b and Abcc1 the activity of only Abcb1b increased significantly in colchicine-selected, drug-resistant cells. Increased transporter expression in drug-resistant cells results primarily from transcriptional activation. A change in histone modification at the regulatory regions of the chromosomally adjacent Abcb1a and Abcb1b genes differentially affects the levels of corresponding mRNAs. Transcriptional up- and down-regulation accompany an increase in acetylation levels of histone H3 lysine 9 at the promoter regions of Abcb1b and Abcb1a, respectively. Drug efflux activity, however, does not follow tightly the transcriptional activity of drug transporter genes in hepatoma cells. Our results point out the need for careful analysis of cause-and-effect relationships between changes in histone modification, drug transporter expression and drug resistance phenotypes.

  9. Induction of actin disruption and downregulation of P-glycoprotein expression by solamargine in multidrug-resistant K562/A02 cells

    Institute of Scientific and Technical Information of China (English)

    LI Xia; ZHAO Ying; JI Mei; LIU Shan-shan; CUI Min; LOU Hong-xiang

    2011-01-01

    Background Solamargine (SM), a steroidal glycoalkaloid isolated from the Chinese herb Solarium incanum, has been shown to inhibit the growth of some cancer cell lines and induce significant apoptosis. However, the effects of SM on multidrug-resistant (MDR) cells and the molecular mechanisms involved are poorly understood. The purpose of this study was to evaluate the anti-MDR effects of SM and the associated mechanisms in MDR K562/A02 cells.Methods The cytotoxicity of SM was measured by 3-(4,5-dimethylthiazol)-2,5-diphenyltetrazolium bromide (MTT) assay. The 14',6-diamidino-2-phenylindole (DAPI) nuclear staining and flow cytometry were used to detect SM-induced apoptosis. The mRNA expression of P-glycoprotein (P-gp) was investigated by real-time PCR (RT-PCR). Western blotting was used to determine the expression of Bcl-2, Bax, and actin. The changes in the morphology of actin were examined with immunofluorescence staining.Results MTT results showed that SM effectively killed the MDR sublines K562/A02, KB/VCR, and H460/paclitaxel (Taxol), and their parental cell lines K562, KB, and H460 to an equivalent or more sensitive degree. Based on the results by flow cytometry and immunostaining, the pro-apoptotic effects of SM were observed in MDR K562/A02 cells. Furthermore, the RT-PCR results showed that SM induced the downregulation of MDR1 mRNA. In addition, the expression of P-gp and actin was decreased in the SM-treated cells, as measured by western blotting and immunostaining.Conclusions These results demonstrate that SM effectively triggers apoptosis in MDR tumor cells, which is associated with actin disruption and downregulation of MDR1 expression. This compound may merit further investigation as a potential therapeutic agent that bypasses the MDR mechanism for the treatment of MDR tumors.

  10. Hepatic gene expression analysis of 2-aminoanthracene exposed Fisher-344 rats reveal patterns indicative of liver carcinoma and type 2 diabetes.

    Science.gov (United States)

    Gato, Worlanyo E; Hales, Dale B; Means, Jay C

    2012-01-01

    The goal of the present study was to examine hepatic differential gene expression patterns in Fisher-344 rats in response to dietary 2-aminoanthracene (2AA) ingestion for 14 and 28 days. Twenty four post-weaning 3-4 week old F-344 male rats were exposed to 0 mgkg(-1)-diet (control), 50 mgkg(-1)-diet (low dose), 75 mgkg(-1)-diet (medium dose) and 100 mgkg(-1)-diet (high dose) 2AA for 14 and 28 days. This was followed by analysis of the liver for global gene expression changes. In both time points, the numbers of genes affected seem to correlate with the dose of 2AA. Sixteen mRNAs were differentially expressed in all treatment groups for the short-term exposure group. Similarly, 51 genes were commonly expressed in all 28-day exposure group. Almost all the genes seem to have higher expression relative to the controls. In contrast, cytochrome P450 family 4, subfamily a, polypeptide 8 (Cyp4a8), and monocyte to macrophage differentiation-associated (Mmd2) were down-regulated relative to controls. Differentially expressed mRNAs were further analyzed for associations via DAVID. GO categories show the effect of 2AA to be linked with genes responsible for carbohydrate utilization and transport, lipid metabolic processes, stress responses such as inflammation and apoptosis processes, immune system response, DNA damage response, cancer processes and circadian rhythm. The data from the current study identified altered hepatic gene expression profiles that may be associated with carcinoma, autoimmune response, and/or type 2 diabetes. Possible biomarkers due to 2AA toxicity in the liver for future study include Abcb1a, Nhej1, Adam8, Cdkn1a, Mgmt, and Nrcam. PMID:23038007

  11. Diversification and expression of the PIN, AUX/LAX and ABCB families of putative auxin transporters in Populus

    Directory of Open Access Journals (Sweden)

    Nicola eCarraro

    2012-02-01

    Full Text Available Intercellular transport of the plant hormone auxin is mediated by three families of membrane-bound protein carriers, with the PIN and ABCB families coding primarily for efflux proteins and the AUX/LAX family coding for influx proteins. In the last decade our understanding of gene and protein function for these transporters in Arabidopsis has expanded rapidly but very little is known about their role in woody plant development. Here we present a comprehensive account of all three families in the model woody species Populus, including chromosome distribution, protein structure, quantitative gene expression, and evolutionary relationships. The PIN and AUX/LAX gene families in Populus comprise 16 and 8 members respectively, and show evidence for the retention of paralogs following a relatively recent whole genome duplication. There is also evidence for differential expression across tissues within many gene pairs. The ABCB family is previously undescribed in Populus and includes 20 members, showing a much deeper evolutionary history including both tandem and whole genome duplication as well as probable loss. A striking number of these transporters are expressed in developing Populus stems and we suggest that evolutionary and structural relationships with known auxin transporters in Arabidopsis can point toward candidate genes for further study in Populus. This is especially important for the ABCBs, which is a large family and includes members in Arabidopsis that are able to transport other substrates in addition to auxin. Protein modeling, sequence alignment and expression data all point to ABCB1.1 as a likely auxin transport protein in Populus. Given that basipetal auxin flow through the cambial zone shapes the development of woody stems, it is important that we identify the full complement of proteins involved in this process. This work should lay the foundation for studies targeting specific proteins for functional characterization and in situ

  12. Effect of piperlongumine on drug resistance reversal in human retinoblastoma HXO-RB44/VCR and SO-Rb50/CBP cell lines.

    Science.gov (United States)

    Wang, Xiao-Qiang; Wang, Yu-Chuan; Guo, Ya-Tu; Tang, Xin

    2015-01-01

    Piperlongumine (PLGM) was considered as an anti-cancer agent since it was involved in suppressing of many types of cancer. To investigate the functions and mechanisms of PLGM on drug resistance reversal in human retinoblastoma cell lines, drug resistance cell lines HXO-RB44/VCR and SO-Rb50/CBP were established. We found that after treatment with PLGM, drug sensitivity and apoptosis rate of these drug resistance cancer cells were improved, cell cycle was arrested, the expressions of P-gp, MDR1, MRP1, Top-II, GST-π, Survivin, Bcl-2, CDK1, ABCB1 and ABCG1 was decreased, while the activities of caspase-3/8 and intracellular content of Rh-123 was increased. Furthermore, the activities of PI3K/AKT and PKCζ pathways were suppressed following PLGM treatment. Therefore, this study suggests that PLGM could reverse the drug resistance of human retinoblastoma cell lines HXO-RB44/VCR and SO-Rb50/CBP. This drug resistance reversing effect might exert via PI3K/AKT and PKCζ pathways. PMID:26045758

  13. Drug-induced trafficking of p-glycoprotein in human brain capillary endothelial cells as demonstrated by exposure to mitomycin C.

    Science.gov (United States)

    Noack, Andreas; Noack, Sandra; Hoffmann, Andrea; Maalouf, Katia; Buettner, Manuela; Couraud, Pierre-Olivier; Romero, Ignacio A; Weksler, Babette; Alms, Dana; Römermann, Kerstin; Naim, Hassan Y; Löscher, Wolfgang

    2014-01-01

    P-glycoprotein (Pgp; ABCB1/MDR1) is a major efflux transporter at the blood-brain barrier (BBB), restricting the penetration of various compounds. In other tissues, trafficking of Pgp from subcellular stores to the cell surface has been demonstrated and may constitute a rapid way of the cell to respond to toxic compounds by functional membrane insertion of the transporter. It is not known whether drug-induced Pgp trafficking also occurs in brain capillary endothelial cells that form the BBB. In this study, trafficking of Pgp was investigated in human brain capillary endothelial cells (hCMEC/D3) that were stably transfected with a doxycycline-inducible MDR1-EGFP fusion plasmid. In the presence of doxycycline, these cells exhibited a 15-fold increase in Pgp-EGFP fusion protein expression, which was associated with an increased efflux of the Pgp substrate rhodamine 123 (Rho123). The chemotherapeutic agent mitomycin C (MMC) was used to study drug-induced trafficking of Pgp. Confocal fluorescence microscopy of single hCMEC/D3-MDR1-EGFP cells revealed that Pgp redistribution from intracellular pools to the cell surface occurred within 2 h of MMC exposure. Pgp-EGFP exhibited a punctuate pattern at the cell surface compatible with concentrated regions of the fusion protein in membrane microdomains, i.e., lipid rafts, which was confirmed by Western blot analysis of biotinylated cell surface proteins in Lubrol-resistant membranes. MMC exposure also increased the functionality of Pgp as assessed in three functional assays with Pgp substrates (Rho123, eFluxx-ID Gold, calcein-AM). However, this increase occurred with some delay after the increased Pgp expression and coincided with the release of Pgp from the Lubrol-resistant membrane complexes. Disrupting rafts by depleting the membrane of cholesterol increased the functionality of Pgp. Our data present the first direct evidence of drug-induced Pgp trafficking at the human BBB and indicate that Pgp has to be released from lipid

  14. Defective canalicular transport and toxicity of dietary ursodeoxycholic acid in the abcb11-/- mouse: transport and gene expression studies.

    Science.gov (United States)

    Wang, Renxue; Liu, Lin; Sheps, Jonathan A; Forrest, Dana; Hofmann, Alan F; Hagey, Lee R; Ling, Victor

    2013-08-15

    The bile salt export pump (BSEP), encoded by the abcb11 gene, is the major canalicular transporter of bile acids from the hepatocyte. BSEP malfunction in humans causes bile acid retention and progressive liver injury, ultimately leading to end-stage liver failure. The natural, hydrophilic, bile acid ursodeoxycholic acid (UDCA) is efficacious in the treatment of cholestatic conditions, such as primary biliary cirrhosis and cholestasis of pregnancy. The beneficial effects of UDCA include promoting bile flow, reducing hepatic inflammation, preventing apoptosis, and maintaining mitochondrial integrity in hepatocytes. However, the role of BSEP in mediating UDCA efficacy is not known. Here, we used abcb11 knockout mice (abcb11-/-) to test the effects of acute and chronic UDCA administration on biliary secretion, bile acid composition, liver histology, and liver gene expression. Acutely infused UDCA, or its taurine conjugate (TUDC), was taken up by the liver but retained, with negligible biliary output, in abcb11-/- mice. Feeding UDCA to abcb11-/- mice led to weight loss, retention of bile acids, elevated liver enzymes, and histological damage to the liver. Semiquantitative RT-PCR showed that genes encoding Mdr1a and Mdr1b (canalicular) as well as Mrp4 (basolateral) transporters were upregulated in abcb11-/- mice. We concluded that infusion of UDCA and TUDC failed to induce bile flow in abcb11-/- mice. UDCA fed to abcb11-/- mice caused liver damage and the appearance of biliary tetra- and penta-hydroxy bile acids. Supplementation with UDCA in the absence of Bsep caused adverse effects in abcb11-/- mice. PMID:23764895

  15. HIF-1 activation induces doxorubicin resistance in MCF7 3-D spheroids via P-glycoprotein expression: a potential model of the chemo-resistance of invasive micropapillary carcinoma of the breast

    Directory of Open Access Journals (Sweden)

    Doublier Sophie

    2012-01-01

    Full Text Available Abstract Background Invasive micropapillary carcinoma (IMPC of the breast is a distinct and aggressive variant of luminal type B breast cancer that does not respond to neoadjuvant chemotherapy. It is characterized by small pseudopapillary clusters of cancer cells with inverted cell polarity. To investigate whether hypoxia-inducible factor-1 (HIF-1 activation may be related to the drug resistance described in this tumor, we used MCF7 cancer cells cultured as 3-D spheroids, which morphologically simulate IMPC cell clusters. Methods HIF-1 activation was measured by EMSA and ELISA in MCF7 3-D spheroids and MCF7 monolayers. Binding of HIF-1α to MDR-1 gene promoter and modulation of P-glycoprotein (Pgp expression was evaluated by ChIP assay and FACS analysis, respectively. Intracellular doxorubicin retention was measured by spectrofluorimetric assay and drug cytotoxicity by annexin V-FITC measurement and caspase activity assay. Results In MCF7 3-D spheroids HIF-1 was activated and recruited to participate to the transcriptional activity of MDR-1 gene, coding for Pgp. In addition, Pgp expression on the surface of cells obtained from 3-D spheroids was increased. MCF7 3-D spheroids accumulate less doxorubicin and are less sensitive to its cytotoxic effects than MCF7 cells cultured as monolayer. Finally, HIF-1α inhibition either by incubating cells with 3-(5'-hydroxymethyl-2'-furyl-1-benzylindazole (a widely used HIF-1α inhibitor or by transfecting cells with specific siRNA for HIF-1α significantly decreased the expression of Pgp on the surface of cells and increased the intracellular doxorubicin accumulation in MCF7 3-D spheroids. Conclusions MCF7 breast cancer cells cultured as 3-D spheroids are resistant to doxorubicin and this resistance is associated with an increased Pgp expression in the plasma membrane via activation of HIF-1. The same mechanism may be suggested for IMPC drug resistance.

  16. MRP-1 expression levels determine strain-specific susceptibility to sodium arsenic-induced renal injury between C57BL/6 and BALB/c mice

    International Nuclear Information System (INIS)

    To clarify the pathophysiological mechanism underlying acute renal injury caused by acute exposure to arsenic, we subcutaneously injected both BALB/c and C57BL/6 mice with sodium arsenite (NaAs; 13.5 mg/kg). BALB/c mice exhibited exaggerated elevation of serum blood urea nitrogen (BUN) and creatinine (CRE) levels, compared with C57BL/6 mice. Moreover, half of BALB/c mice died by 24 h, whereas all C57BL/6 mice survived. Histopathological examination on kidney revealed severe hemorrhages, acute tubular necrosis, neutrophil infiltration, cast formation, and disappearance of PAS-positive brush borders in BALB/c mice, later than 10 h. These pathological changes were remarkably attenuated in C57BL/6 mice, accompanied with lower intrarenal arsenic concentrations, compared with BALB/c mice. Among heavy metal inducible proteins including multidrug resistance-associated protein (MRP)-1, multidrug resistance gene (MDR)-1, metallothionein (MT)-1, and arsenite inducible, cysteine- and histidine-rich RNA-associated protein (AIRAP), intrarenal MDR-1, MT-1, and AIRAP gene expression was enhanced to a similar extent in both strains, whereas NaAs challenge augmented intrarenal MRP-1 mRNA and protein expression levels in C57BL/6 but not BALB/c mice. Moreover, the administration of a specific inhibitor of MRP-1, MK-571, significantly exaggerated acute renal injury in C57BL/6 mice. Thus, MRP-1 is crucially involved in arsenic efflux and eventually prevention of acute renal injury upon acute exposure to NaAs

  17. Differential Gene Expression across Breed and Sex in Commercial Pigs Administered Fenbendazole and Flunixin Meglumine.

    Science.gov (United States)

    Howard, Jeremy T; O'Nan, Audrey T; Maltecca, Christian; Baynes, Ronald E; Ashwell, Melissa S

    2015-01-01

    Characterizing the variability in transcript levels across breeds and sex in swine for genes that play a role in drug metabolism may shed light on breed and sex differences in drug metabolism. The objective of the study is to determine if there is heterogeneity between swine breeds and sex in transcript levels for genes previously shown to play a role in drug metabolism for animals administered flunixin meglumine or fenbendazole. Crossbred nursery female and castrated male pigs (n = 169) spread across 5 groups were utilized. Sires (n = 15) of the pigs were purebred Duroc, Landrace, Yorkshire or Hampshire boars mated to a common sow population. Animals were randomly placed into the following treatments: no drug (control), flunixin meglumine, or fenbendazole. One hour after the second dosing, animals were sacrificed and liver samples collected. Quantitative Real-Time PCR was used to measure liver gene expression of the following genes: SULT1A1, ABCB1, CYP1A2, CYP2E1, CYP3A22 and CYP3A29. The control animals were used to investigate baseline transcript level differences across breed and sex. Post drug administration transcript differences across breed and sex were investigated by comparing animals administered the drug to the controls. Contrasts to determine fold change were constructed from a model that included fixed and random effects within each drug. Significant (P-value fenbendazole, respectively. The current analysis found transcript level differences across swine breeds and sex for multiple genes, which provides greater insight into the relationship between flunixin meglumine and fenbendazole and known drug metabolizing genes.

  18. Modulation of multidrug resistance 1 expression and function in retinoblastoma cells by curcumin

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    Seethalakshmi Sreenivasan

    2013-01-01

    Full Text Available Objective: To determine the possible interaction of curcumin with P-glycoprotein (P-gp expression and function by in vitro and in silico studies. Materials and Methods: In this study, curcumin was compared for its potential to modulate the expression and function of P-gp in Y79 RB cells by western blot, RT-PCR (reverse transcription polymerase chain reaction and functional assay. Further, in silico molecular modeling and docking simulations were performed to deduce the inhibitory binding mode of curcumin. Results: Western blot and RT-PCR analysis decreased the expression of P-gp in a dose-dependent manner. The effect of curcumin on P-gp function was demonstrated by Rhodamine 123 (Rh123 accumulation and efflux study. Curcumin increased the accumulation of Rh123 and decreased its efflux in retinoblastoma (RB cells. In addition, curcumin inhibited verapamil stimulated ATPase activity and photoaffinity labeling study showed no effect on the binding of 8-azido-ATP-biotin, indicating its interaction at the substrate binding site. Moreover, molecular docking studies concurrently infer the binding of curcumin into the substrate binding site of P-gp with a binding energy of -7.66 kcal/mol. Conclusion: These findings indicate that curcumin suppresses the MDR1 expression and function, and therefore may be useful as modulators of multidrug resistance in RB tumor.

  19. Marine sponge-derived sipholane triterpenoids reverse P-glycoprotein (ABCB1)-mediated multidrug resistance in cancer cells

    OpenAIRE

    Abraham, Ioana; Jain, Sandeep; Wu, Chung-pu; Khanfar, Mohammad A.; Kuang, Yehong; Dai, Chun-ling; Shi, Zhi; Chen, Xiang; FU, LIWU; Suresh V Ambudkar; Sayed, Khalid El; Chen, Zhe-Sheng

    2010-01-01

    Previously, we reported sipholenol A, a sipholane triterpenoid from the Red Sea sponge Callyspongia siphonella, as a potent reversal of multidrug resistance (MDR) in cancer cells that overexpressed P-glycoprotein (P-gp). Through extensive screening of several related sipholane triterpenoids that have been isolated from the same sponge, we identified sipholenone E, sipholenol L and siphonellinol D as potent reversals of MDR in cancer cells. These compounds enhanced the cytotoxicity of several ...

  20. The function of the ATP-binding cassette (ABC) transporter ABCB1 is not susceptible to actin disruption

    NARCIS (Netherlands)

    Meszaros, Peter; Hummel, Ina; Klappe, Karin; Draghiciu, Oana; Hoekstra, Dick; Kok, Jan W.

    2013-01-01

    Previously we have shown that the activity of the multidrug transporter ABCC1 (multidrug resistance protein 1), and its localization in lipid rafts, depends on cortical actin (Hummel I, Klappe K, Ercan C, Kok JW. Mol. Pharm. 2011 79, 229-40). Here we show that the efflux activity of the ATP-binding

  1. Impact of ABCB1 Variants on Neutrophil Depression: A Pharmacogenomic Study of Paclitaxel in 92 Women with Ovarian Cancer

    DEFF Research Database (Denmark)

    Bergmann, Troels K; Andersen, Charlotte Brasch; Gréen, Henrik;

    2012-01-01

      The standard treatment for ovarian cancer in advanced stages is post-surgery treatment with taxane-platin chemotherapy. Despite an initial high response rate, most patients eventually relapse. The dose-limiting toxicities of paclitaxel are neutropenia and neuropathy, but the inter-individual va...

  2. Hedgehog Pathway Inhibitor HhAntag691 Is a Potent Inhibitor of ABCG2/BCRP and ABCB1/Pgp1

    OpenAIRE

    Zhang, Yimao; Laterra, John; Pomper, Martin G.

    2009-01-01

    HhAntag691 (GDC-0449), a low-molecular weight inhibitor of the tumor-promoting hedgehog (Hh) signaling pathway, has been used to treat medulloblastoma in animal models and has recently entered clinical trials for a variety of solid tumors. Here, we show that HhAntag691 inhibits multiple ATP-binding cassette (ABC) transporters. ATP-binding cassette transporters are within a family of membrane proteins, the overexpression of which is associated with multidrug resistance, a major impediment to s...

  3. Contribution of cytochrome P450 and ABCB1 genetic variability on methadone pharmacokinetics, dose requirements, and response.

    Directory of Open Access Journals (Sweden)

    Francina Fonseca

    Full Text Available Although the efficacy of methadone maintenance treatment (MMT in opioid dependence disorder has been well established, the influence of methadone pharmacokinetics in dose requirement and clinical outcome remains controversial. The aim of this study is to analyze methadone dosage in responder and nonresponder patients considering pharmacogenetic and pharmacokinetic factors that may contribute to dosage adequacy. Opioid dependence patients (meeting Diagnostic and Statistical Manual of Mental Disorders, [4(th Edition] criteria from a MMT community program were recruited. Patients were clinically assessed and blood samples were obtained to determine plasma concentrations of (R,S-, (R and (S-methadone and to study allelic variants of genes encoding CYP3A5, CYP2D6, CYP2B6, CYP2C9, CYP2C19, and P-glycoprotein. Responders and nonresponders were defined by illicit opioid consumption detected in random urinalysis. The final sample consisted in 105 opioid dependent patients of Caucasian origin. Responder patients received higher doses of methadone and have been included into treatment for a longer period. No differences were found in terms of genotype frequencies between groups. Only CYP2D6 metabolizing phenotype differences were found in outcome status, methadone dose requirements, and plasma concentrations, being higher in the ultrarapid metabolizers. No other differences were found between phenotype and responder status, methadone dose requirements, neither in methadone plasma concentrations. Pharmacokinetic factors could explain some but not all differences in MMT outcome and methadone dose requirements.

  4. Non-coplanar polychlorinated biphenyls (PCBs) are direct agonists for the human pregnane-X receptor and constitutive androstane receptor, and activate target gene expression in a tissue-specific manner

    International Nuclear Information System (INIS)

    The polychlorinated biphenyl group possesses high environmental persistence, leading to bioaccumulation and a number of adverse effects in mammals. Whilst coplanar PCBs elicit their toxic effects through agonism of the aryl hydrocarbon receptor; however, non-coplanar PCBs are not ligands for AhR, but may be ligands for members of the nuclear receptor family of proteins. To better understand the biological actions of non-coplanar PCBs, we have undertaken a systematic analysis of their ability to activate PXR and CAR-mediated effects. Cells were exposed to a range of non-coplanar PCBs (99, 138, 153, 180 and 194), or the coplanar PCB77: Direct activation of PXR and CAR was measured using a mammalian receptor activation assay in human liver cells, with rifampicin and CITCO used as positive controls ligands for PXR and CAR, respectively; activation of target gene expression was examined using reporter gene plasmids for CYP3A4 and MDR1 transfected into liver, intestine and lung cell lines. Several of the non-coplanar PCBs directly activated PXR and CAR, whilst the coplanar PCB77 did not. Non-coplanar PCBs were also able to activate PXR/CAR target gene expression in a substitution- and tissue-specific manner. Non-coplanar PCBs act as direct activators for the nuclear receptors PXR and CAR, and are able to elicit transcriptional activation of target genes in a substitution- and tissue-dependent manner. Chronic activation of PXR/CAR is linked to adverse effects and must be included in any risk assessment of PCBs. -- Highlights: ► Several Non-coplanar PCBs are able to directly activate both PXR and CAR in vitro. ► PCB153 is the most potent direct activator of PXR and CAR nuclear receptors. ► Non-coplanar PCB activation of CYP3A4/MDR1 reporter genes is structure-dependent. ► Non-coplanar PCB activate CYP3A4/MDR1 reporter genes in a tissue-dependent. ► PCB153 is the most potent activator of PXR/CAR target gene in all tissues.

  5. Non-coplanar polychlorinated biphenyls (PCBs) are direct agonists for the human pregnane-X receptor and constitutive androstane receptor, and activate target gene expression in a tissue-specific manner

    Energy Technology Data Exchange (ETDEWEB)

    Al-Salman, Fadheela; Plant, Nick, E-mail: N.Plant@Surrey.ac.uk

    2012-08-15

    The polychlorinated biphenyl group possesses high environmental persistence, leading to bioaccumulation and a number of adverse effects in mammals. Whilst coplanar PCBs elicit their toxic effects through agonism of the aryl hydrocarbon receptor; however, non-coplanar PCBs are not ligands for AhR, but may be ligands for members of the nuclear receptor family of proteins. To better understand the biological actions of non-coplanar PCBs, we have undertaken a systematic analysis of their ability to activate PXR and CAR-mediated effects. Cells were exposed to a range of non-coplanar PCBs (99, 138, 153, 180 and 194), or the coplanar PCB77: Direct activation of PXR and CAR was measured using a mammalian receptor activation assay in human liver cells, with rifampicin and CITCO used as positive controls ligands for PXR and CAR, respectively; activation of target gene expression was examined using reporter gene plasmids for CYP3A4 and MDR1 transfected into liver, intestine and lung cell lines. Several of the non-coplanar PCBs directly activated PXR and CAR, whilst the coplanar PCB77 did not. Non-coplanar PCBs were also able to activate PXR/CAR target gene expression in a substitution- and tissue-specific manner. Non-coplanar PCBs act as direct activators for the nuclear receptors PXR and CAR, and are able to elicit transcriptional activation of target genes in a substitution- and tissue-dependent manner. Chronic activation of PXR/CAR is linked to adverse effects and must be included in any risk assessment of PCBs. -- Highlights: ► Several Non-coplanar PCBs are able to directly activate both PXR and CAR in vitro. ► PCB153 is the most potent direct activator of PXR and CAR nuclear receptors. ► Non-coplanar PCB activation of CYP3A4/MDR1 reporter genes is structure-dependent. ► Non-coplanar PCB activate CYP3A4/MDR1 reporter genes in a tissue-dependent. ► PCB153 is the most potent activator of PXR/CAR target gene in all tissues.

  6. Radioprotection of 1,2-dimethylhydrazine-initiated colon cancer in rats using low-dose γ rays by modulating multidrug resistance-1, cytokeratin 20, and β-catenin expression.

    Science.gov (United States)

    Nabil, H M; Hassan, B N; Tohamy, A A; Waaer, H F; Abdel Moneim, A E

    2016-03-01

    Ionizing radiation is a widely used therapy for solid tumors. However, high-dose ionizing radiation causes apoptosis, transforms normal cells into tumor cells, and impairs immune functions, leading to the defects in the removal of damaged or tumor cells. In contrast, low-dose radiation has been reported to exert various beneficial effects in cells. This experimental study investigated the effect of γ rays at low dose on the development of colorectal tumor in a 1,2-dimethylhydrazine (DMH)-induced colon cancer. Colorectal tumor model was induced in Wistar rats by subcutaneous injection of DMH (20 mg/kg) once a week for 15 weeks. Starting from zero day of DMH injection, a single low dose of whole-body γ irradiation of 0.5 Gy/week was applied to the rats. A significant reduction in lipid peroxidation, nitric oxide, and elevation in the glutathione content and antioxidant enzyme activity (superoxide dismutase and catalase) were observed after γ irradiation comparing with DMH group. Moreover, γ ray reduced the expressions of multidrug resistance 1 (MDR1), β-catenin, and cytokeratin 20 (CK20) those increased in DMH-treated rats. However, survivin did not change with γ ray treatment. A histopathological examination of the DMH-injected rats revealed ulcerative colitis, dysplasia, anaplasia, and hyperchromasia. An improvement in the histopathological picture was seen in the colon of rats exposed to γ rays. In conclusion, the present results showed that low-dose γ ray significantly inhibited DMH-induced colon carcinogenesis in rats by modulating CK20, MDR1, and β-catenin expression but not survivin expression.

  7. Estudio del proceso de sensibilidad colateral en células leucémicas murinas y humanas con fenotipo de resistencia a múltiples fármacos (MDR).

    OpenAIRE

    Cerezo Fernández, David

    2013-01-01

    INTRODUCCIÓN: La adquisición del fenotipo de resistencia a múltiples fármacos (MDR) en células tumorales las convierte en resistentes a fármacos antineoplásicos y es una de las principales causas del fracaso de la quimioterapia en algunos tumores. La expresión de glicoproteína P (MDR-1, P-gp, ABCB1) contribuye a esta resistencia expulsando los fármacos o regulando la muerte celular programada. Por otro lado, la sobreexpresión de miembros anti-apoptóticos de la familia Bcl-2 observada en tumor...

  8. Drug-induced trafficking of p-glycoprotein in human brain capillary endothelial cells as demonstrated by exposure to mitomycin C.

    OpenAIRE

    Noack, Andreas; Noack, Sandra; Hoffmann, Andrea; Maalouf, Katia; Buettner, Manuela; Couraud, Pierre-Olivier; Romero, Ignacio A.; Weksler, Babette; Alms, Dana; Römermann, Kerstin; Naim, Hassan Y; Löscher, Wolfgang

    2014-01-01

    P-glycoprotein (Pgp; ABCB1/MDR1) is a major efflux transporter at the blood-brain barrier (BBB), restricting the penetration of various compounds. In other tissues, trafficking of Pgp from subcellular stores to the cell surface has been demonstrated and may constitute a rapid way of the cell to respond to toxic compounds by functional membrane insertion of the transporter. It is not known whether drug-induced Pgp trafficking also occurs in brain capillary endothelial cells that form the BBB. ...

  9. Protein kinase C-dependent regulation of human hepatic drug transporter expression.

    Science.gov (United States)

    Mayati, Abdullah; Le Vee, Marc; Moreau, Amélie; Jouan, Elodie; Bucher, Simon; Stieger, Bruno; Denizot, Claire; Parmentier, Yannick; Fardel, Olivier

    2015-12-15

    Hepatic drug transporters are now recognized as major actors of hepatobiliary elimination of drugs. Characterization of their regulatory pathways is therefore an important issue. In this context, the present study was designed to analyze the potential regulation of human hepatic transporter expression by protein kinase C (PKC) activation. Treatment by the reference PKC activator phorbol 12-myristate 13-acetate (PMA) for 48h was shown to decrease mRNA expression of various sinusoidal transporters, including OATP1B1, OATP2B1, NTCP, OCT1 and MRP3, but to increase that of OATP1B3, whereas mRNA expression of canalicular transporters was transiently enhanced (MDR1), decreased (BSEP and MRP2) or unchanged (BCRP) in human hepatoma HepaRG cells. The profile of hepatic transporter mRNA expression changes in PMA-treated HepaRG cells was correlated to that found in PMA-exposed primary human hepatocytes and was similarly observed in response to the PKC-activating marketed drug ingenol mebutate. It was associated with concomitant repression of OATP1B1 and OATP2B1 protein expression and reduction of OATP, OCT1, NTCP and MRP2 activity. The use of chemical PKC inhibitors further suggested a contribution of novel PKCs isoforms to PMA-mediated regulations of transporter mRNA expression. PMA was finally shown to cause epithelial-mesenchymal transition (EMT) in HepaRG cells and exposure to various additional EMT inducers, i.e., hepatocyte growth factor, tumor growth factor-β1 or the HNF4α inhibitor BI6015, led to transporter expression alterations highly correlated to those triggered by PMA. Taken together, these data highlight PKC-dependent regulation of human hepatic drug transporter expression, which may be closely linked to EMT triggered by PKC activation. PMID:26462574

  10. 微小RNA-451在乳腺癌细胞中的表达及其与耐药的关系%Expression of miR-451 and its correlation with drug resistance in breast cancer cells

    Institute of Scientific and Technical Information of China (English)

    李智敏; 罗喜平; 王泽华; 胡沙; 殷文静; 孙小丽

    2012-01-01

    Objective: To investigate the expression of miR-451 in breast cancer cells and its correlation with drug resistance to ADM (adriamycin). Methods: Stem-loop real-time PCR was used to detect the expression of miR-451 (microRNA-451) in breast cancer MCF-7 cells and their ADM-resistant cells (MCF-7/ADM). The mimics of miR-451 and the negative control RNA (NC) were transfected into MCF-7/ADM cells by LipofectAMINE 2000. The expression levels of MDR1 (multi-drug resistance gene 1) mRNA and P-gp (P-glycoprotein) protein were examined using real-time fluorescence quantitative PCR and Western blotting, respectively. MTT was used to analyze the proliferation of MCF-7/ADM cells transfected with miR-451 mimics and treated with ADM at different concentrations. Results: The expression level of miR-451 was lower in MCF-7/ADM cells than in MCF-7 cells (P < 0.05). The expressions of MDR1 mRNA and P-gp protein were decreased in MCF-7/ADM cells after transfection with miR-451 mimics as compared with those in the NC group (P < 0.05). The sensitivity of MCF-7/ADM cells transfected with miR-451 mimics and treated with ADM was enhanced and the IC50 (half inhibition concentration) value of ADM in miR-451 mimics transfection group was less than that of the NC group (P < 0.05). Conclusion: The expression of miR-451 is down-regulated in breast cancer ADM-resistant cells, which may play a vital role in drug resistance by regulating the expression of MDR1 /P-gp.%目的:研究人类微小RNA-451 (Homo sapiens microRNA-451,hsa-miR-451)在乳腺癌细胞中的表达及其与多柔比星(adriamycin,ADM)耐药的关系.方法:用实时荧光定量PCR一步法检测乳腺癌亲本细胞MCF-7和耐ADM细胞MCF-7/ADM中hsa-miR-451的表达;利用脂质体分别将成熟miR-451的模拟物(mimics)及阴性对照转染MCF-7/ADM细胞,然后采用实时荧光定量PCR法检测细胞中多药耐药基因1(multi-drug resistance gene 1,MDR1)mRNA的表达,蛋白质印迹法检测细胞中P-糖蛋白(P

  11. Human ABC transporter ABCG2/BCRP expression in chemoresistance: basic and clinical perspectives for molecular cancer therapeutics

    Directory of Open Access Journals (Sweden)

    Noguchi K

    2014-02-01

    Full Text Available Kohji Noguchi, Kazuhiro Katayama, Yoshikazu Sugimoto Division of Chemotherapy, Faculty of Pharmacy, Keio University, Tokyo, Japan Abstract: Adenine triphosphate (ATP-binding cassette (ABC transporter proteins, such as ABCB1/P-glycoprotein (P-gp and ABCG2/breast cancer resistance protein (BCRP, transport various structurally unrelated compounds out of cells. ABCG2/BCRP is referred to as a “half-type” ABC transporter, functioning as a homodimer, and transports anticancer agents such as irinotecan, 7-ethyl-10-hydroxycamptothecin (SN-38, gefitinib, imatinib, methotrexate, and mitoxantrone from cells. The expression of ABCG2/BCRP can confer a multidrug-resistant phenotype on cancer cells and affect drug absorption, distribution, metabolism, and excretion in normal tissues, thus modulating the in vivo efficacy of chemotherapeutic agents. Clarification of the substrate preferences and structural relationships of ABCG2/BCRP is essential for our understanding of the molecular mechanisms underlying its effects in vivo during chemotherapy. Its single-nucleotide polymorphisms are also involved in determining the efficacy of chemotherapeutics, and those that reduce the functional activity of ABCG2/BCRP might be associated with unexpected adverse effects from normal doses of anticancer drugs that are ABCG2/BCRP substrates. Importantly, many recently developed molecular-targeted cancer drugs, such as the tyrosine kinase inhisbitors, imatinib mesylate, gefitinib, and others, can also interact with ABCG2/BCRP. Both functional single-nucleotide polymorphisms and inhibitory agents of ABCG2/BCRP modulate the in vivo pharmacokinetics and pharmacodynamics of these molecular cancer treatments, so the pharmacogenetics of ABCG2/BCRP is an important consideration in the application of molecular-targeted chemotherapies. Keywords: kinase inhibitor, SNP, single-nucleotide polymorphisms, molecular target

  12. MicroRNA-133b targets glutathione S-transferase π expression to increase ovarian cancer cell sensitivity to chemotherapy drugs

    Directory of Open Access Journals (Sweden)

    Chen S

    2015-09-01

    Full Text Available Shuo Chen,1 Jin-Wen Jiao,2 Kai-Xuan Sun,1 Zhi-Hong Zong,3 Yang Zhao1 1Department of Gynecology, The First Affiliated Hospital of China Medical University, Shenyang, People’s Republic of China; 2Department of Gynecology, The Affiliated Hospital of Medical College, Qingdao University, Qingdao, People’s Republic of China; 3Department of Biochemistry and Molecular Biology, College of Basic Medicine, China Medical University, Shenyang, People’s Republic of China Background: Accumulating studies reveal that aberrant microRNA (miRNA expression can affect the development of chemotherapy drug resistance by modulating the expression of relevant target proteins. The aim of this study was to investigate the role of miR-133b in the development of drug resistance in ovarian cancer cells. Methods: We examined the levels of miR-133b expression in ovarian carcinoma tissues and the human ovarian carcinoma cell lines (A2780, A2780/DDP and A2780/Taxol, respectively. We determined the cell viability of these cell lines treated with cisplatin or paclitaxel in the presence or absence of miR-133b or anti-miR-133b transfection using the MTT assay. Reverse transcription polymerase chain reaction and Western blotting were used to assess the mRNA and protein expression levels of two drug-resistance-related genes: glutathione S-transferase (GST-π and multidrug resistance protein 1 (MDR1. The dual-luciferase reporter assay was used to detect the promoter activity of GST-π in the presence and absence of miR-133b. Results: The expression of miR-133b was significantly lower in primary resistant ovarian carcinomas than in the chemotherapy-sensitive carcinomas (P<0.05, and the same results were found in primary resistant ovarian cell lines (A2780/Taxol and A2780/DDP compared to the chemotherapy-sensitive cell line (A2780; P<0.05. Following miR-133b transfection, four cell lines showed increased sensitivity to paclitaxel and cisplatin, while anti-miR-133b transfection

  13. Effects of vanillin and ethyl vanillin on mRNA expression of transport proteins in liver of rats%香兰素与乙基香兰素对大鼠肝脏中转运蛋白mRNA表达的影响

    Institute of Scientific and Technical Information of China (English)

    孟沫然; 魏敏; 王玲; 罗诚浩; 陈义坤; 陈勇

    2012-01-01

    目的 研究香兰素、乙基香兰素对大鼠肝脏中多药耐药基因Mdr1、多药耐药相关蛋白Mrp2、阴离子转运蛋白Oatp1A1和阳离子转运蛋白Oct1 mRNA表达水平的影响.方法 大鼠ig香兰素或乙基香兰素3、15、75 mg/(kg·d),连续给药7d,提取肝脏总RNA,逆转录后荧光定量PCR检测细胞膜Mdr1、Mrp2、Oatp1A1和Oct1 mRNA的表达.结果 香兰素、乙基香兰素均能显著上调Mdr1 mRNA的表达,下调Oatp1A1、Oct1 mRNA的表达,对Mrp2 mRNA的表达无显著影响.结论 香兰素、乙基香兰素给药后能提高肝细胞Mdr1对药物的外排作用,减弱Oatp1A1、Oct1对药物的摄取能力,当香兰素和乙基香兰素与上述转运体底物药物共用时,可能会发生药物相互作用.%Objective To study the effects of vanillin and ethyl vanillin on the mRNA expression levels of multidrug resistance gene Mdrl, multidrug resistance-associated protein Mrp2, organic anion transporter Oatpl Al, and organic cation transporter Octl in liver of rats. Methods Wistar rats were ig administered with vanillin or ethyl vanillin at three dosage levels [3, 15, and 75 mg/(kg-d)] for consecutive 7 d, then the mRNA expression levels of Mdrl, Mrp2, OatplAl, and Octl in liver tissue of rats were detected by reverse-transcriptase fluorescence quantitative PCR. Results Both vanillin and ethyl vanillin had no significant effect on the mRNA expressions of Mrp2, but up-regulated mRNA expression of Mdrl and down-regulated those of OatplAl and Octl markedly. Conclusion Vanillin and ethyl vanillin could increase the drug excretion by Mdrl in hepatocyte, and attenuate the drug intake capacity by OatplAl and Octl. The drug interaction is possible when vanillin and ethyl vanillin are used combined with the above transporter substrates.

  14. Multiple Origins of Mutations in the mdr1 Gene--A Putative Marker of Chloroquine Resistance in P. vivax.

    Directory of Open Access Journals (Sweden)

    Mette L Schousboe

    2015-11-01

    Full Text Available Chloroquine combined with primaquine has been the recommended antimalarial treatment of Plasmodium vivax malaria infections for six decades but the efficacy of this treatment regimen is threatened by chloroquine resistance (CQR. Single nucleotide polymorphisms (SNPs in the multidrug resistance gene, Pvmdr1 are putative determinants of CQR but the extent of their emergence at population level remains to be explored.In this study we describe the prevalence of SNPs in the Pvmdr1 among samples collected in seven P. vivax endemic countries and we looked for molecular evidence of drug selection by characterising polymorphism at microsatellite (MS loci flanking the Pvmdr1 gene.We examined the prevalence of SNPs in the Pvmdr1 gene among 267 samples collected from Pakistan, Afghanistan, Sri Lanka, Nepal, Sudan, São Tomé and Ecuador. We measured and diversity in four microsatellite (MS markers flanking the Pvmdr1 gene to look evidence of selection on mutant alleles.SNP polymorphism in the Pvmdr1 gene was largely confined to codons T958M, Y976F and F1076L. Only 2.4% of samples were wildtype at all three codons (TYF, n = 5, 13.3% (n = 28 of the samples were single mutant MYF, 63.0% of samples (n = 133 were double mutant MYL, and 21.3% (n = 45 were triple mutant MFL. Clear geographic differences in the prevalence of these Pvmdr mutation combinations were observed. Significant linkage disequilibrium (LD between Pvmdr1 and MS alleles was found in populations sampled in Ecuador, Nepal and Sri Lanka, while significant LD between Pvmdr1 and the combined 4 MS locus haplotype was only seen in Ecuador and Sri Lanka. When combining the 5 loci, high level diversity, measured as expected heterozygosity (He, was seen in the complete sample set (He = 0.99, while He estimates for individual loci ranged from 0.00-0.93. Although Pvmdr1 haplotypes were not consistently associated with specific flanking MS alleles, there was significant differentiation between geographic sites which could indicate directional selection through local drug pressure.Our observations suggest that Pvmdr1 mutations emerged independently on multiple occasions even within the same population. In Sri Lanka population analysis at multiple sites showed evidence of local selection and geographical dispersal of Pvmdr1 mutations between sites.

  15. Multiple Origins of Mutations in the mdr1 Gene—A Putative Marker of Chloroquine Resistance in P. vivax

    DEFF Research Database (Denmark)

    Schousboe, Mette L; Ranjitkar, Samir; Rajakaruna, Rupika S;

    2015-01-01

    resistance gene, Pvmdr1 are putative determinants of CQR but the extent of their emergence at population level remains to be explored. OBJECTIVE: In this study we describe the prevalence of SNPs in the Pvmdr1 among samples collected in seven P. vivax endemic countries and we looked for molecular evidence...

  16. Intracellular targeted co-delivery of shMDR1 and gefitinib with chitosan nanoparticles for overcoming multidrug resistance

    OpenAIRE

    Yu XW; Yang G; Shi YJ; Su C; Liu M; Feng B; Zhao L

    2015-01-01

    Xiwei Yu,1,* Guang Yang,2,* Yijie Shi,1 Chang Su,3 Ming Liu,1 Bo Feng,1 Liang Zhao1 1School of Pharmacy, Liaoning Medical University, Jinzhou, People’s Republic of China; 2Department of Oncology, BenQ Medical Center, Nanjing Medical University, Nanjing, People’s Republic of China; 3School of Veterinary Medicine, Liaoning Medical University, Jinzhou, People’s Republic of China *These authors contributed equally to this work Abstract: Nowadays, multidrug resista...

  17. Uptake of compounds that selectively kill multidrug-resistant cells: the copper transporter SLC31A1 (CTR1) increases cellular accumulation of the thiosemicarbazone NSC73306.

    Science.gov (United States)

    Fung, King Leung; Tepede, Abisola K; Pluchino, Kristen M; Pouliot, Lynn M; Pixley, Jessica N; Hall, Matthew D; Gottesman, Michael M

    2014-08-01

    Acquired drug resistance in cancer continues to be a challenge in cancer therapy, in part due to overexpression of the drug efflux transporter P-glycoprotein (P-gp, MDR1, ABCB1). NSC73306 is a thiosemicarbazone compound that displays greater toxicity against cells expressing functional P-gp than against other cells. Here, we investigate the cellular uptake of NSC73306, and examine its interaction with P-gp and copper transporter 1 (CTR1, SLC31A1). Overexpression of P-gp sensitizes LLC-PK1 cells to NSC73306. Cisplatin (IC50 = 77 μM), cyclosporin A (IC50 = 500 μM), and verapamil (IC50 = 700 μM) inhibited cellular accumulation of [(3)H]NSC73306. Cellular hypertoxicity of NSC73306 to P-gp-expressing cells was inhibited by cisplatin in a dose-dependent manner. Cells transiently expressing the cisplatin uptake transporter CTR1 (SLC31A1) showed increased [(3)H]NSC73306 accumulation. In contrast, CTR1 knockdown decreased [(3)H]NSC73306 accumulation. The presence of NSC73306 reduced CTR1 levels, similar to the negative feedback of CTR1 levels by copper or cisplatin. Surprisingly, although cisplatin is a substrate of CTR1, we found that CTR1 protein was overexpressed in high-level cisplatin-resistant KB-CP20 and BEL7404-CP20 cell lines. We confirmed that the CTR1 protein was functional, as uptake of NSC73306 was increased in KB-CP20 cells compared to their drug-sensitive parental cells, and downregulation of CTR1 in KB-CP20 cells reduced [(3)H]NSC73306 accumulation. These results suggest that NSC73306 is a transport substrate of CTR1. PMID:24800945

  18. Allele-Selective Transcriptome Recruitment to Polysomes Primed for Translation: Protein-Coding and Noncoding RNAs, and RNA Isoforms.

    Directory of Open Access Journals (Sweden)

    Roshan Mascarenhas

    Full Text Available mRNA translation into proteins is highly regulated, but the role of mRNA isoforms, noncoding RNAs (ncRNAs, and genetic variants remains poorly understood. mRNA levels on polysomes have been shown to correlate well with expressed protein levels, pointing to polysomal loading as a critical factor. To study regulation and genetic factors of protein translation we measured levels and allelic ratios of mRNAs and ncRNAs (including microRNAs in lymphoblast cell lines (LCL and in polysomal fractions. We first used targeted assays to measure polysomal loading of mRNA alleles, confirming reported genetic effects on translation of OPRM1 and NAT1, and detecting no effect of rs1045642 (3435C>T in ABCB1 (MDR1 on polysomal loading while supporting previous results showing increased mRNA turnover of the 3435T allele. Use of high-throughput sequencing of complete transcript profiles (RNA-Seq in three LCLs revealed significant differences in polysomal loading of individual RNA classes and isoforms. Correlated polysomal distribution between protein-coding and non-coding RNAs suggests interactions between them. Allele-selective polysome recruitment revealed strong genetic influence for multiple RNAs, attributable either to differential expression of RNA isoforms or to differential loading onto polysomes, the latter defining a direct genetic effect on translation. Genes identified by different allelic RNA ratios between cytosol and polysomes were enriched with published expression quantitative trait loci (eQTLs affecting RNA functions, and associations with clinical phenotypes. Polysomal RNA-Seq combined with allelic ratio analysis provides a powerful approach to study polysomal RNA recruitment and regulatory variants affecting protein translation.

  19. An integrative genomic analysis revealed the relevance of microRNA and gene expression for drug-resistance in human breast cancer cells

    Directory of Open Access Journals (Sweden)

    Yamamoto Yusuke

    2011-11-01

    Full Text Available Abstract Background Acquisition of drug-resistance in cancer has led to treatment failure, however, their mechanisms have not been clarified yet. Recent observations indicated that aberrant expressed microRNA (miRNA caused by chromosomal alterations play a critical role in the initiation and progression of cancer. Here, we performed an integrated genomic analysis combined with array-based comparative hybridization, miRNA, and gene expression microarray to elucidate the mechanism of drug-resistance. Results Through genomic approaches in MCF7-ADR; a drug-resistant breast cancer cell line, our results reflect the unique features of drug-resistance, including MDR1 overexpression via genomic amplification and miRNA-mediated TP53INP1 down-regulation. Using a gain of function study with 12 miRNAs whose expressions were down-regulated and genome regions were deleted, we show that miR-505 is a novel tumor suppressive miRNA and inhibits cell proliferation by inducing apoptosis. We also find that Akt3, correlate inversely with miR-505, modulates drug sensitivity in MCF7-ADR. Conclusion These findings indicate that various genes and miRNAs orchestrate to temper the drug-resistance in cancer cells, and thus acquisition of drug-resistance is intricately controlled by genomic status, gene and miRNA expression changes.

  20. Neuronal and glial expression of the multidrug resistance gene product in an experimental epilepsy model.

    Science.gov (United States)

    Lazarowski, Alberto; Ramos, Alberto Javier; García-Rivello, Hernán; Brusco, Alicia; Girardi, Elena

    2004-02-01

    1. Failure of anticonvulsive drugs to prevent seizures is a common complication of epilepsy treatment known as drug-refractory epilepsy but their causes are not well understood. It is hypothesized that the multidrug resistance P-glycoprotein (Pgp-170), the product of the MDR-1 gene that is normally expressed in several excretory tissues including the blood brain barrier, may be participating in the refractory epilepsy. 2. Using two monoclonal antibodies against Pgp-170, we investigated the expression and cellular distribution of this protein in the rat brain during experimentally induced epilepsy. Repeated seizures were induced in male Wistar rats by daily administration of 3-mercaptopropionic acid (MP) 45 mg/kg i.p. for either 4 days (MP-4) or 7 days (MP-7). Control rats received an equivalent volume of vehicle. One day after the last injection, rats were sacrificed and brains were processed for immunohistochemistry for Pgp-170. As it was previously described, Pgp-170 immunostaining was observed in some brain capillary endothelial cells of animals from control group. 3. Increased Pgp-170 immunoreactivity was detected in MP-treated animals. Besides the Pgp-170 expressed in blood vessels, neuronal, and glial immunostaining was detected in hippocampus, striatum, and cerebral cortex of MP-treated rats. Pgp-170 immunolabeled neurons and glial cells were observed in a nonhomogeneous distribution. MP-4 animals presented a very prominent Pgp-170 immunostaining in the capillary endothelium, surrounding astrocytes and some neighboring neurons while MP-7 group showed increased neuronal labeling. 4. Our results demonstrate a selective increase in Pgp-170 immunoreactivity in the brain capillary endothelial cells, astrocytes, and neurons during repetitive MP-induced seizures. 5. The role for this Pgp-170 overexpression in endothelium and astrocytes as a clearance mechanism in the refractory epilepsy, and the consequences of neuronal Pgp-170 expression remain to be disclosed.

  1. Tumor endothelial expression of P-glycoprotein upon microvesicular transfer of TrpC5 derived from adriamycin-resistant breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Dong, YePing; Pan, QiongXi; Jiang, Li; Chen, Zhen; Zhang, FangFang; Liu, YanJun; Xing, Hui; Shi, Mei; Li, Jiao; Li, XiYuan; Zhu, YaoDan; Chen, Yun; Bruce, Iain C.; Jin, Jian, E-mail: jinjian31@126.com; Ma, Xin, E-mail: maxin@jiangnan.edu.cn

    2014-03-28

    Highlights: • TrpC5 was mainly accumulated in microvesicles of drug-resistant MCF-7/ADM cells. • Microvesicles from MCF-7/ADM transferred TrpC5 to endothelial cells. • TrpC5 inhibition reduced P-glycoprotein accumulation on tumor blood vessels in vivo. - Abstract: Treatment of carcinoma commonly fails due to chemoresistance. Studies have shown that endothelial cells acquire resistance via the tumor microenvironment. Microvesicle (MV) shedding from the cell membrane to the microenvironment plays an important role in communication between cells. The aim of the present study was to determine whether MCF-7 adriamycin-resistant cells (MCF-7/ADM) shed MVs that alter the characteristics of human microvessel endothelial cells (HMECs). MVs from tumor cells transferred a Ca{sup 2+}-permeable channel TrpC5 to HMECs, inducing the expression of P-glycoprotein (P-gp) by activation of the transcription factor NFATc3 (nuclear factor of activated T cells isoform c3). Expression of the mdr1 gene was blocked by the TrpC5-blocking antibody T5E3, and the production of P-gp in HMECs was reduced by blockade of TrpC5. Thus, we postulate that endothelial cells acquire the resistant protein upon exposure to TrpC5-containg MVs in the microenvironment, and express P-gp in the TrpC5–NFATc3 signal pathway.

  2. 碱性成纤维细胞生长因子单克隆抗体通过P-糖蛋白逆转乳腺癌MCF-7/ADM细胞多药耐药性的分子机制%Molecular mechanism of reversal effect of monoclonal antibody to basic fibroblast growth factor-mediated expression of P-glycoprotein on multiple drug resistance in adriamycin-resistant human breast cancer cell line MCF-7/ADM

    Institute of Scientific and Technical Information of China (English)

    陈文慧; 徐萌; 杜超超; 赵建夫; 潘兰红; 李汉初; 向军俭; 邓宁

    2013-01-01

    Objective: To investigate the mechanism of reversal effect of bFGF mAb (monoclonal antibody to basic fibroblast growth factor)-mediated expression of P-gp (permeability glycoprotein) on MDR (multidrug resistance) in ADM (adriamycin)-resistant human breast cancer cell line MCF-7/ADM. Methods: The effects of bFGF mAb on the proliferation of MCF-7/ADM cells and the reversal of MDR were detected by CCK-8 (cell counting kit-8) method. The cell cycle distribution of MCF-7/ADM cells and the expression of P-gp and intracellular fluorescence intensity of Rho123 (rhodamine 123) in MCF-7/ADM cells after bFGF mAb intervention were analyzed by flow cytometry. The expressions of MDR 1 (multidrug resistance protein 1) and bFGF mRNAs in MCF-7/ADM cells were examined by real-time fluorescence quantitative PCR. Results: The growth inhibition rates of MCF-7 cells and MCF-7/ADM cells after treatment with 1 μj/mL bFGF mAb were (1 9.87+1.05)% and (27.34±2.79)% (P < 0.01). bFGF mAb intervention could reverse ADM-, GEM (gemcitabine)- and OXA (oxaliplatin)-resistance of MCF-7/ADM cells, and the corresponding reversal index were 4.46, 4.25 and 2.18, respectively. As compared with the MCF-7/ADM cells without bFGF mAb intervention, the cell cycle of MCF-7/ADM cells after bFGF mAb intervention was arrested at G0/G1 phase, the expression level of P-gp was down-regulated, the intracellular Rho123 fluorescence intensity was increased, and the expression levels of MDR 1 and bFGF mRNAs were both decreased (P < 0.01). Conclusion: bFGF mAb can inhibit the proliferation of MCF-7/ADM and reverse MDR. This mechanism may be related to down-regulation of the expression levels of MDR 1 and P-gp, inhibition of the function of P-gp, and increasement of intracellular concentration of chemotherapeutic drugs.%目的:探讨碱性成纤维细胞生长因子单克隆抗体(monoclonal antibody to basic fibroblast growth factor,bFGF mAb)通过P-糖蛋白(permeability glycoprotein,P-gp)对人乳腺癌多柔比

  3. Targeting glucosylceramide synthase induction of cell surface globotriaosylceramide (Gb3) in acquired cisplatin-resistance of lung cancer and malignant pleural mesothelioma cells

    International Nuclear Information System (INIS)

    Background: Acquired resistance to cisplatin treatment is a caveat when treating patients with non-small cell lung cancer (NSCLC) and malignant pleural mesothelioma (MPM). Ceramide increases in response to chemotherapy, leading to proliferation arrest and apoptosis. However, a tumour stress activation of glucosylceramide synthase (GCS) follows to eliminate ceramide by formation of glycosphingolipids (GSLs) such as globotriaosylceramide (Gb3), the functional receptor of verotoxin-1. Ceramide elimination enhances cell proliferation and apoptosis blockade, thus stimulating tumor progression. GSLs transactivate multidrug resistance 1/P-glycoprotein (MDR1) and multidrug resistance-associated protein 1 (MRP1) expression which further prevents ceramide accumulation and stimulates drug efflux. We investigated the expression of Gb3, MDR1 and MRP1 in NSCLC and MPM cells with acquired cisplatin resistance, and if GCS activity or MDR1 pump inhibitors would reduce their expression and reverse cisplatin-resistance. Methods: Cell surface expression of Gb3, MDR1 and MRP1 and intracellular expression of MDR1 and MRP1 was analyzed by flow cytometry and confocal microscopy on P31 MPM and H1299 NSCLC cells and subline cells with acquired cisplatin resistance. The effect of GCS inhibitor PPMP and MDR1 pump inhibitor cyclosporin A for 72 h on expression and cisplatin cytotoxicity was tested. Results: The cisplatin-resistant cells expressed increased cell surface Gb3. Cell surface Gb3 expression of resistant cells was annihilated by PPMP whereas cyclosporin A decreased Gb3 and MDR1 expression in H1299 cells. No decrease of MDR1 by PPMP was noted in using flow cytometry, whereas a decrease of MDR1 in H1299 and H1299res was indicated with confocal microscopy. No certain co-localization of Gb3 and MDR1 was noted. PPMP, but not cyclosporin A, potentiated cisplatin cytotoxicity in all cells. Conclusions: Cell surface Gb3 expression is a likely tumour biomarker for acquired cisplatin

  4. Targeting glucosylceramide synthase induction of cell surface globotriaosylceramide (Gb3) in acquired cisplatin-resistance of lung cancer and malignant pleural mesothelioma cells

    Energy Technology Data Exchange (ETDEWEB)

    Tyler, Andreas, E-mail: andreas.tyler@medbio.umu.se [Department of Medical Biosciences, Umeå University, S-901 85 Umea (Sweden); Johansson, Anders [Department of Odontology, Umeå University, S-901 85 Umea (Sweden); Karlsson, Terese [Department of Radiation Sciences, Oncology, S-901 85 Umea (Sweden); Gudey, Shyam Kumar; Brännström, Thomas; Grankvist, Kjell; Behnam-Motlagh, Parviz [Department of Medical Biosciences, Umeå University, S-901 85 Umea (Sweden)

    2015-08-01

    Background: Acquired resistance to cisplatin treatment is a caveat when treating patients with non-small cell lung cancer (NSCLC) and malignant pleural mesothelioma (MPM). Ceramide increases in response to chemotherapy, leading to proliferation arrest and apoptosis. However, a tumour stress activation of glucosylceramide synthase (GCS) follows to eliminate ceramide by formation of glycosphingolipids (GSLs) such as globotriaosylceramide (Gb3), the functional receptor of verotoxin-1. Ceramide elimination enhances cell proliferation and apoptosis blockade, thus stimulating tumor progression. GSLs transactivate multidrug resistance 1/P-glycoprotein (MDR1) and multidrug resistance-associated protein 1 (MRP1) expression which further prevents ceramide accumulation and stimulates drug efflux. We investigated the expression of Gb3, MDR1 and MRP1 in NSCLC and MPM cells with acquired cisplatin resistance, and if GCS activity or MDR1 pump inhibitors would reduce their expression and reverse cisplatin-resistance. Methods: Cell surface expression of Gb3, MDR1 and MRP1 and intracellular expression of MDR1 and MRP1 was analyzed by flow cytometry and confocal microscopy on P31 MPM and H1299 NSCLC cells and subline cells with acquired cisplatin resistance. The effect of GCS inhibitor PPMP and MDR1 pump inhibitor cyclosporin A for 72 h on expression and cisplatin cytotoxicity was tested. Results: The cisplatin-resistant cells expressed increased cell surface Gb3. Cell surface Gb3 expression of resistant cells was annihilated by PPMP whereas cyclosporin A decreased Gb3 and MDR1 expression in H1299 cells. No decrease of MDR1 by PPMP was noted in using flow cytometry, whereas a decrease of MDR1 in H1299 and H1299res was indicated with confocal microscopy. No certain co-localization of Gb3 and MDR1 was noted. PPMP, but not cyclosporin A, potentiated cisplatin cytotoxicity in all cells. Conclusions: Cell surface Gb3 expression is a likely tumour biomarker for acquired cisplatin

  5. Potentiation of Anticancer Drugs: Effects of Pentoxifylline on Neoplastic Cells

    Directory of Open Access Journals (Sweden)

    Miroslav Barancik

    2011-12-01

    Full Text Available The drug efflux activity of P-glycoprotein (P-gp, a product of the mdr1 gene, ABCB1 member of ABC transporter family represents a mechanism by which tumor cells escape death induced by chemotherapeutics. In this study, we investigated the mechanisms involved in the effects of pentoxifylline (PTX on P-gp-mediated multidrug resistance (MDR in mouse leukemia L1210/VCR cells. Parental sensitive mouse leukemia cells L1210, and multidrug-resistant cells, L1210/VCR, which are characterized by the overexpression of P-gp, were used as experimental models. The cells were exposed to 100 μmol/L PTX in the presence or absence of 1.2 μmol/L vincristine (VCR. Western blot analysis indicated a downregulation of P-gp protein expression when multidrug-resistant L1210/VCR cells were exposed to PTX. The effects of PTX on the sensitization of L1210/VCR cells to VCR correlate with the stimulation of apoptosis detected by Annexin V/propidium iodide apoptosis necrosis kit and proteolytic activation of both caspase-3 and caspase-9 monitored by Western blot analysis. Higher release of matrix metalloproteinases (MMPs, especially MMP-2, which could be attenuated by PTX, was found in L1210/VCR than in L1210 cells by gelatin zymography in electrophoretic gel. Exposure of resistant cells to PTX increased the content of phosphorylated Akt kinase. In contrast, the presence of VCR eliminated the effects of PTX on Akt kinase phosphorylation. Taken together, we conclude that PTX induces the sensitization of multidrug-resistant cells to VCR via downregulation of P-gp, stimulation of apoptosis and reduction of MMPs released from drug-resistant L1210/VCR cells. These facts bring new insights into the mechanisms of PTX action on cancer cells.

  6. Sensitive and specific fluorescent probes for functional analysis of the three major types of mammalian ABC transporters.

    Directory of Open Access Journals (Sweden)

    Irina V Lebedeva

    Full Text Available An underlying mechanism for multi drug resistance (MDR is up-regulation of the transmembrane ATP-binding cassette (ABC transporter proteins. ABC transporters also determine the general fate and effect of pharmaceutical agents in the body. The three major types of ABC transporters are MDR1 (P-gp, P-glycoprotein, ABCB1, MRP1/2 (ABCC1/2 and BCRP/MXR (ABCG2 proteins. Flow cytometry (FCM allows determination of the functional expression levels of ABC transporters in live cells, but most dyes used as indicators (rhodamine 123, DiOC(2(3, calcein-AM have limited applicability as they do not detect all three major types of ABC transporters. Dyes with broad coverage (such as doxorubicin, daunorubicin and mitoxantrone lack sensitivity due to overall dimness and thus may yield a significant percentage of false negative results. We describe two novel fluorescent probes that are substrates for all three common types of ABC transporters and can serve as indicators of MDR in flow cytometry assays using live cells. The probes exhibit fast internalization, favorable uptake/efflux kinetics and high sensitivity of MDR detection, as established by multidrug resistance activity factor (MAF values and Kolmogorov-Smirnov statistical analysis. Used in combination with general or specific inhibitors of ABC transporters, both dyes readily identify functional efflux and are capable of detecting small levels of efflux as well as defining the type of multidrug resistance. The assay can be applied to the screening of putative modulators of ABC transporters, facilitating rapid, reproducible, specific and relatively simple functional detection of ABC transporter activity, and ready implementation on widely available instruments.

  7. EXPRESSION AND REVERSION OF DRUG RESISTANCE-AND APOPTOSIS-RELATED GENES OF A DDP-RESISTANT LUNG ADENOCARCINOMA CELL LINE

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective: To investigate the co-expression of drug resistance- and apoptosis-related genes of cisplatin (CDDP)-selected lung adenocarcinoma cell line A549DDP for compared to the parental cell line A549, and reverse of drug resistance by antisense s-oligodeoxynucleotides (S-ODNs) of differentially expressed genes. Methods: Sense and antisense S-ODN were transferred into A549DDP cells by lipofectin. The expression of drug resistance and apoptosis related genes was examined by RT-PCR, immunocytochemistry and flow cytometry, respectively. Apoptostic cells were identified by DNA electrophoresis and terminal deoxynucleotidyl transferase (TdT)-mediated biotin dUTP nick end-labeling(TUNEL). Drug resistance of tumor cells was detected by a cell viability (MTT) assay. Results: The expression of bc1-2 was positive and that of multidrug resistance-associated protein (MRP) at mRNA and protein level was increased in A549DDP compared to A549 cells. MDR1, c-myc and topoisomeras II (TOPO II) were similarly co-expressed in two cell lines. Both cell lines were negative for c-erbB-2 expression. In A549DDP cells, the expression of bc1-2 and MRP was significantly inhibited by their respective antisense S-ODNs. Antisense S-ODNs could also decrease significantly drug resistance of A549DDP cells to CDDP by promoting cell apoptosis. Conclusion: Both intrinsic and acquired drug resistance were involved in co-expression of multiple MDR-related genes in lung adenocarcinoma. Co- operation of bc1-2 and MRP genes appeared to play an important action to confer the resistance of A549DDP cells to CDDP. Their antisense S-ODNs are responsible for the decrease of drug resistance of this cell line by promoting apoptosis.

  8. Structure and expression of the human MDR (P-glycoprotein) gene family.

    OpenAIRE

    Chin, J E; Soffir, R; Noonan, K E; Choi, K.; Roninson, I B

    1989-01-01

    The human MDR (P-glycoprotein) gene family is known to include two members, MDR1 and MDR2. The product of the MDR1 gene, which is responsible for resistance to different cytotoxic drugs (multidrug resistance), appears to serve as an energy-dependent efflux pump for various lipophilic compounds. The function of the MDR2 gene remains unknown. We have examined the structure of the human MDR gene family by Southern hybridization of DNA from different multidrug-resistant cell lines with subfragmen...

  9. Effects of methylmercury contained in a diet mimicking the Wayana Amerindians contamination through fish consumption: mercury accumulation, metallothionein induction, gene expression variations, and role of the chemokine CCL2.

    Science.gov (United States)

    Bourdineaud, Jean-Paul; Laclau, Muriel; Maury-Brachet, Régine; Gonzalez, Patrice; Baudrimont, Magalie; Mesmer-Dudons, Nathalie; Fujimura, Masatake; Marighetto, Aline; Godefroy, David; Rostène, William; Brèthes, Daniel

    2012-01-01

    Methylmercury (MeHg) is a potent neurotoxin, and human beings are mainly exposed to this pollutant through fish consumption. We addressed the question of whether a diet mimicking the fish consumption of Wayanas Amerindians from French Guiana could result in observable adverse effects in mice. Wayanas adult men are subjected to a mean mercurial dose of 7 g Hg/week/kg of body weight. We decided to supplement a vegetarian-based mice diet with 0.1% of lyophilized Hoplias aimara fish, which Wayanas are fond of and equivalent to the same dose as that afflicting the Wayanas Amerindians. Total mercury contents were 1.4 ± 0.2 and 5.4 ± 0.5 ng Hg/g of food pellets for the control and aimara diets, respectively. After 14 months of exposure, the body parts and tissues displaying the highest mercury concentration on a dry weight (dw) basis were hair (733 ng/g) and kidney (511 ng/g), followed by the liver (77 ng/g). Surprisingly, despite the fact that MeHg is a neurotoxic compound, the brain accumulated low levels of mercury (35 ng/g in the cortex). The metallothionein (MT) protein concentration only increased in those tissues (kidney, muscles) in which MeHg demethylation had occurred. This can be taken as a molecular sign of divalent mercurial contamination since only Hg(2+) has been reported yet to induce MT accumulation in contaminated tissues. The suppression of the synthesis of the chemokine CCL2 in the corresponding knockout (KO) mice resulted in important changes in gene expression patterns in the liver and brain. After three months of exposure to an aimara-containing diet, eight of 10 genes selected (Sdhb, Cytb, Cox1, Sod1, Sod2, Mt2, Mdr1a and Bax) were repressed in wild-type mice liver whereas none presented a differential expression in KO Ccl2(-/-) mice. In the wild-type mice brain, six of 12 genes selected (Cytb, Cox1, Sod1, Sod2, Mdr1a and Bax) presented a stimulated expression, whereas all remained at the basal level of expression in KO Ccl2(-/-) mice. In the

  10. Characterization of rhodamine-123 as a tracer dye for use in in vitro drug transport assays.

    Directory of Open Access Journals (Sweden)

    Samantha Forster

    Full Text Available Fluorescent tracer dyes represent an important class of sub-cellular probes and allow the examination of cellular processes in real-time with minimal impact upon these processes. Such tracer dyes are becoming increasingly used for the examination of membrane transport processes, as they are easy-to-use, cost effective probe substrates for a number of membrane protein transporters. Rhodamine 123, a member of the rhodamine family of flurone dyes, has been used to examine membrane transport by the ABCB1 gene product, MDR1. MDR1 is viewed as the archetypal drug transport protein, and is able to efflux a large number of clinically relevant drugs. In addition, ectopic activity of MDR1 has been associated with the development of multiple drug resistance phenotype, which results in a poor patient response to therapeutic intervention. It is thus important to be able to examine the potential for novel compounds to be MDR1 substrates. Given the increasing use rhodamine 123 as a tracer dye for MDR1, a full characterisation of its spectral properties in a range of in vitro assay-relevant media is warranted. Herein, we determine λmax for excitation and emission or rhodamine 123 and its metabolite rhodamine 110 in commonly used solvents and extraction buffers, demonstrating that fluorescence is highly dependent on the chemical environment: Optimal parameters are 1% (v/v methanol in HBSS, with λex = 505 nm, λem = 525 nm. We characterise the uptake of rhodamine 123 into cells, via both passive and active processes, and demonstrate that this occurs primarily through OATP1A2-mediated facilitated transport at concentrations below 2 µM, and via micelle-mediated passive diffusion above this. Finally, we quantify the intracellular sequestration and metabolism of rhodamine 123, demonstrating that these are both cell line-dependent factors that may influence the interpretation of transport assays.

  11. Impact of High ABCA3 Expression in Nasopharyngeal Carcinoma Stem Cells on theResistance to Cisplatin%鼻咽癌肿瘤干细胞高表达 ABCA3在顺铂耐药机制中的作用∗

    Institute of Scientific and Technical Information of China (English)

    林碧华; 陈婧; 卢家淇; 余海波; 张鑫; 周克元

    2015-01-01

    目的:探讨 ABC 转运体家族在鼻咽癌肿瘤干细胞表达及对顺铂耐药机制的作用。方法通过罗丹明123外排实验及钠钾 ATP 酶活性检测,观察鼻咽癌细胞 CNE ̄2与鼻咽癌肿瘤干细胞 CNE ̄2S 之间药物外排能力的差异。运用实时定量 RT ̄PCR 技术,测定两种细胞在顺铂作用下6个 ABC 转运体家族成员 mRNA 的表达情况,并采用 Western blot 检测 ABCA3、ABCC1、ABCC2及 ABCG2的蛋白表达水平。利用小分子 RNA 干扰技术沉默 ABCA3基因后,观察两种细胞药物外排及顺铂诱导的凋亡情况。结果顺铂对 CNE ̄2S 的半数抑制浓度(IC50)为 CNE ̄2的4.1倍(P<0.05),同时CNE ̄2S 的相对药物外排活性为 CNE ̄2的4.8倍(P<0.05)。 CNE ̄2S 较 CNE ̄2高表达 ABCA3、ABCB1、ABCC1及 ABCG2(P<0.05)。1μmol.L-1顺铂作用48 h 后,ABCA3在 CNE ̄2S 中特异性高表达,沉默 ABCA3后能显著抑制 CNE ̄2S 的药物外排能力(P<0.05),并增强顺铂对 CNE ̄2S 及 CNE ̄2的诱导凋亡能力(P<0.05)。结论鼻咽癌肿瘤干细胞对顺铂耐药与高表达 ABCA3、ABCC1及 ABCG2有关,抑制 ABCA3的表达能逆转肿瘤干细胞对顺铂的杀伤作用。%Objective To investigate the role of ATP ̄binding cassette ( ABC ) family on the resistance of nasopharyngeal carcinoma (NPC) stem cells (CSCs) to cisplatin. Methods We compared the differences between the drug extravasation capability of CNE ̄2 and CNE ̄2S by using Rhodamine ̄123 efflux assay. We determined the mRNA and protein expression levels of ABC transport family members, including ABCA3,ABCB1,ABCB5,ABCC1,ABCC2 and ABCG2,after 48 h being treated with 1 μmol.L-1 cisplatin by RT ̄PC and Western blotting.Rhoamine ̄123 efflux and apoptosis by cisplatin in two kinds of cells was examined by ABCA3 gene silencing with specific small ̄interfering RNA. Results The IC50 of cisplatin on CNE ̄2S was 4.1 fold to that on CNE ̄2(P<0.05).For the relative drug effluent activity and Na

  12. Induction of multixenobiotic defense mechanisms in resistant Daphnia magna clones as a general cellular response to stress.

    Science.gov (United States)

    Jordão, Rita; Campos, Bruno; Lemos, Marco F L; Soares, Amadeu M V M; Tauler, Romà; Barata, Carlos

    2016-06-01

    Multixenobiotic resistance mechanisms (MXR) were recently identified in Daphnia magna. Previous results characterized gene transcripts of genes encoding and efflux activities of four putative ABCB1 and ABCC transporters that were chemically induced but showed low specificity against model transporter substrates and inhibitors, thus preventing us from distinguishing between activities of different efflux transporter types. In this study we report on the specificity of induction of ABC transporters and of the stress protein hsp70 in clones selected to be genetically resistant to ABCB1 chemical substrates. Clones resistant to mitoxantrone, ivermectin and pentachlorophenol showed distinctive transcriptional responses of transporter protein coding genes and of putative transporter dye activities. Expression of hsp70 proteins also varied across resistant clones. Clones resistant to mitoxantrone and pentachlorophenol showed high constitutive levels of hsp70. Transcriptional levels of the abcb1 gene transporter and of putative dye transporter activity were also induced to a greater extent in the pentachlorophenol resistant clone. Observed higher dye transporter activities in individuals from clones resistant to mitoxantrone and ivermectin were unrelated with transcriptional levels of the studied four abcc and abcb1 transporter genes. These findings suggest that Abcb1 induction in D. magna may be a part of a general cellular stress response. PMID:27039215

  13. Design, synthesis, and biological evaluation of (S)-valine thiazole-derived cyclic and noncyclic peptidomimetic oligomers as modulators of human P-glycoprotein (ABCB1).

    Science.gov (United States)

    Singh, Satyakam; Prasad, Nagarajan Rajendra; Kapoor, Khyati; Chufan, Eduardo E; Patel, Bhargav A; Ambudkar, Suresh V; Talele, Tanaji T

    2014-01-01

    Multidrug resistance caused by ATP binding cassette transporter P-glycoprotein (P-gp) through extrusion of anticancer drugs from the cells is a major cause of failure in cancer chemotherapy. Previously, selenazole-containing cyclic peptides were reported as P-gp inhibitors and were also used for co-crystallization with mouse P-gp, which has 87 % homology to human P-gp. It has been reported that human P-gp can simultaneously accommodate two to three moderately sized molecules at the drug binding pocket. Our in silico analysis, based on the homology model of human P-gp, spurred our efforts to investigate the optimal size of (S)-valine-derived thiazole units that can be accommodated at the drug binding pocket. Towards this goal, we synthesized varying lengths of linear and cyclic derivatives of (S)-valine-derived thiazole units to investigate the optimal size, lipophilicity, and structural form (linear or cyclic) of valine-derived thiazole peptides that can be accommodated in the P-gp binding pocket and affects its activity, previously an unexplored concept. Among these oligomers, lipophilic linear (13) and cyclic trimer (17) derivatives of QZ59S-SSS were found to be the most and equally potent inhibitors of human P-gp (IC50 =1.5 μM). As the cyclic trimer and linear trimer compounds are equipotent, future studies should focus on noncyclic counterparts of cyclic peptides maintaining linear trimer length. A binding model of the linear trimer 13 within the drug binding site on the homology model of human P-gp represents an opportunity for future optimization, specifically replacing valine and thiazole groups in the noncyclic form.

  14. Acute kidney injury in a preterm infant homozygous for the C3435T polymorphism in the ABCB1 gene given oral morphine

    OpenAIRE

    Pogliani, Laura; Mameli, Chiara; Cattaneo, Dario; Clementi, Emilio; Meneghin, Fabio; Radice, Sonia; Bruno, Simona; Zuccotti, Gian Vincenzo

    2012-01-01

    A 34-week infant born from a mother with a history of drug abuse developed neonatal abstinence syndrome (NAS) in the first hours of life. Urine drug screening was positive for cocaine and heroin. The infant developed acute kidney injury and bilateral hydronephrosis while receiving oral morphine for control of NAS. Cessation of morphine therapy and urinary catheterization resulted in a rapid and complete resolution of the symptoms. Our patient was homozygous for the C3435T polymorphism in the ...

  15. Asclepiasterol, a novel C21 steroidal glycoside derived from Asclepias curassavica, reverses tumor multidrug resistance by down-regulating P-glycoprotein expression.

    Science.gov (United States)

    Yuan, Wei-Qi; Zhang, Rong-Rong; Wang, Jun; Ma, Yan; Li, Wen-Xue; Jiang, Ren-Wang; Cai, Shao-Hui

    2016-05-24

    Multidrug resistance (MDR) mediated by P-glycoprotein (P-gp) is a major cause of cancer therapy failure. In this study, we identified a novel C21 steroidal glycoside, asclepiasterol, capable of reversing P-gp-mediated MDR. Asclepiasterol (2.5 and 5.0μM) enhanced the cytotoxity of P-gp substrate anticancer drugs in MCF-7/ADR and HepG-2/ADM cells. MDR cells were more responsive to paclitaxel in the presence of asclepiasterol, and colony formation of MDR cells was only reduced upon treatment with a combination of asclepiasterol and doxorubicin. Consistent with these findings, asclepiasterol treatment increased the intracellular accumulation of doxorubicin and rhodamine 123 (Rh123) in MDR cells. Asclepiasterol decreased expression of P-gp protein without stimulating or suppressing MDR1 mRNA levels. Asclepiasterol-mediated P-gp suppression caused inhibition of ERK1/2 phosphorylation in two MDR cell types, and EGF, an activator of the MAPK/ERK pathway, reversed the P-gp down-regulation, implicating the MAPK/ERK pathway in asclepiasterol-mediated P-gp down-regulation. These results suggest that asclepiasterol could be developed as a modulator for reversing P-gp-mediated MDR in P-gp-overexpressing cancer variants. PMID:27129170

  16. The effect of acetaminophen on the expression of BCRP in trophoblast cells impairs the placental barrier to bile acids during maternal cholestasis

    International Nuclear Information System (INIS)

    Acetaminophen is used as first-choice drug for pain relief during pregnancy. Here we have investigated the effect of acetaminophen at subtoxic doses on the expression of ABC export pumps in trophoblast cells and its functional repercussion on the placental barrier during maternal cholestasis. The incubation of human choriocarcinoma cells (JAr, JEG-3 and BeWo) with acetaminophen for 48 h resulted in no significant changes in the expression and/or activity of MDR1 and MRPs. In contrast, in JEG-3 cells, BCRP mRNA, protein, and transport activity were reduced. In rat placenta, collected at term, acetaminophen administration for the last three days of pregnancy resulted in enhanced mRNA, but not protein, levels of Mrp1 and Bcrp. In fact, a decrease in Bcrp protein was found. Using in situ perfused rat placenta, a reduction in the Bcrp-dependent fetal-to-maternal bile acid transport after treating the dams with acetaminophen was found. Complete biliary obstruction in pregnant rats induced a significant bile acid accumulation in fetal serum and tissues, which was further enhanced when the mothers were treated with acetaminophen. This drug induced increased ROS production in JEG-3 cells and decreased the total glutathione content in rat placenta. Moreover, the NRF2 pathway was activated in JEG-3 cells as shown by an increase in nuclear NRF2 levels and an up-regulation of NRF2 target genes, NQO1 and HMOX-1, which was not observed in rat placenta. In conclusion, acetaminophen induces in placenta oxidative stress and a down-regulation of BCRP/Bcrp, which may impair the placental barrier to bile acids during maternal cholestasis. - Highlights: • Acetaminophen induces changes in placental BCRP expression in vitro. • This drug reduces the ability of placental cells to export BCRP substrates. • Acetaminophen induces changes in Bcrp expression in rat placenta. • Placental barrier to bile acids is impaired in rats treated with this drug

  17. The effect of acetaminophen on the expression of BCRP in trophoblast cells impairs the placental barrier to bile acids during maternal cholestasis

    Energy Technology Data Exchange (ETDEWEB)

    Blazquez, Alba G., E-mail: albamgb@usal.es [Laboratory of Experimental Hepatology and Drug Targeting (HEVEFARM), IBSAL, University of Salamanca, Salamanca (Spain); CIBERehd, Instituto de Salud Carlos III, Madrid (Spain); Briz, Oscar, E-mail: obriz@usal.es [Laboratory of Experimental Hepatology and Drug Targeting (HEVEFARM), IBSAL, University of Salamanca, Salamanca (Spain); CIBERehd, Instituto de Salud Carlos III, Madrid (Spain); Gonzalez-Sanchez, Ester, E-mail: u60343@usal.es [Laboratory of Experimental Hepatology and Drug Targeting (HEVEFARM), IBSAL, University of Salamanca, Salamanca (Spain); Perez, Maria J., E-mail: mjperez@usal.es [Laboratory of Experimental Hepatology and Drug Targeting (HEVEFARM), IBSAL, University of Salamanca, Salamanca (Spain); University Hospital of Salamanca, IECSCYL-IBSAL, Salamanca (Spain); CIBERehd, Instituto de Salud Carlos III, Madrid (Spain); Ghanem, Carolina I., E-mail: cghanem@ffyb.uba.ar [Instituto de Investigaciones Farmacologicas, Facultad de Farmacia y Bioquimica, CONICET, Universidad de Buenos Aires, Buenos Aires (Argentina); Marin, Jose J.G., E-mail: jjgmarin@usal.es [Laboratory of Experimental Hepatology and Drug Targeting (HEVEFARM), IBSAL, University of Salamanca, Salamanca (Spain); CIBERehd, Instituto de Salud Carlos III, Madrid (Spain)

    2014-05-15

    Acetaminophen is used as first-choice drug for pain relief during pregnancy. Here we have investigated the effect of acetaminophen at subtoxic doses on the expression of ABC export pumps in trophoblast cells and its functional repercussion on the placental barrier during maternal cholestasis. The incubation of human choriocarcinoma cells (JAr, JEG-3 and BeWo) with acetaminophen for 48 h resulted in no significant changes in the expression and/or activity of MDR1 and MRPs. In contrast, in JEG-3 cells, BCRP mRNA, protein, and transport activity were reduced. In rat placenta, collected at term, acetaminophen administration for the last three days of pregnancy resulted in enhanced mRNA, but not protein, levels of Mrp1 and Bcrp. In fact, a decrease in Bcrp protein was found. Using in situ perfused rat placenta, a reduction in the Bcrp-dependent fetal-to-maternal bile acid transport after treating the dams with acetaminophen was found. Complete biliary obstruction in pregnant rats induced a significant bile acid accumulation in fetal serum and tissues, which was further enhanced when the mothers were treated with acetaminophen. This drug induced increased ROS production in JEG-3 cells and decreased the total glutathione content in rat placenta. Moreover, the NRF2 pathway was activated in JEG-3 cells as shown by an increase in nuclear NRF2 levels and an up-regulation of NRF2 target genes, NQO1 and HMOX-1, which was not observed in rat placenta. In conclusion, acetaminophen induces in placenta oxidative stress and a down-regulation of BCRP/Bcrp, which may impair the placental barrier to bile acids during maternal cholestasis. - Highlights: • Acetaminophen induces changes in placental BCRP expression in vitro. • This drug reduces the ability of placental cells to export BCRP substrates. • Acetaminophen induces changes in Bcrp expression in rat placenta. • Placental barrier to bile acids is impaired in rats treated with this drug.

  18. Establishment of human glioblastoma multiform multidrug resistant cell line in vitro and identification of its biological characteristics%人脑胶质瘤多药耐药细胞株的构建及生物学特性鉴定

    Institute of Scientific and Technical Information of China (English)

    白义凤; 廖红展; 刘天助; 郭洪波

    2011-01-01

    Objective To establish the imatinib (STI-571)-resistant subline in vitro and investigate its biological characteristics. Methods Human glioblastoma multiform drug-resistant cell line (named U251AR) was established in vitro by successively increasing the concentration of imatinib in a cell culture medium. The 50% inhibitory dose (IC50) values and the resistance indexes ([IC50U251/STI-571]/[IC50 U251]) for other chemotherapeutic agents were evaluated using cell counting kit-8 assays. Expressions of acquired multidrug resistance P-glycoprotein (MDR 1, ABCB 1; MDR3, ABCB4),breast cancer resistance protein (BCRP, ABCG2) and multidrug resistance-associated protein 1 (MRP1,ABCC1) were detected by QRT-PCR. Flow cytometry was employed to detect the protein expression of ABCG2. Results The U251AR was developed after culture for 12 months and similar morphologies of U251 and U251/STI-571 cells were determined. The resistance coefficient of U251AR cells to imatinib was 20.41 times more than that of the parent cells, and U251AR cells showed cross-resistance to many anti-tumor agents (P<0.05). The resistance coefficients of U251AR cell line to doxorubicin and cisplatin were 5.06 and 10.28 times, respectively, more than those of U251 cells (P<0.05). QRT-PCR indicated that the mRNA levels of MDR1, MRP1, BCRPandABCB4 (P-g4) in the U251/STI571 resistant cells were significantly higher than those in the U251 cells (P<0.05). The protein expression of ABCG2 in U251AR cell line was significantly increased as compared with that in the parent cells (P<0.05).Conclusion We have successfully established multidrug resistant cell line U251AR, and the drug resistance of U251/STI571 is associated with over-expressions of ABCC1, ABCB1, ABCB4, and ABCG2 mRNA, and ABCG2 protein.%目的 体外构建胶质瘤耐甲磺酸伊玛替尼多药耐药细胞株,并研究其生物学特性。方法采用逐渐增加培养基中伊玛替尼药物浓度的方法诱导构建耐甲磺酸

  19. Gene expression

    International Nuclear Information System (INIS)

    We prepared probes for isolating functional pieces of the metallothionein locus. The probes enabled a variety of experiments, eventually revealing two mechanisms for metallothionein gene expression, the order of the DNA coding units at the locus, and the location of the gene site in its chromosome. Once the switch regulating metallothionein synthesis was located, it could be joined by recombinant DNA methods to other, unrelated genes, then reintroduced into cells by gene-transfer techniques. The expression of these recombinant genes could then be induced by exposing the cells to Zn2+ or Cd2+. We would thus take advantage of the clearly defined switching properties of the metallothionein gene to manipulate the expression of other, perhaps normally constitutive, genes. Already, despite an incomplete understanding of how the regulatory switch of the metallothionein locus operates, such experiments have been performed successfully

  20. Detection of drug-resistance genes using single bronchoscopy biopsy specimens.

    Science.gov (United States)

    Trussardi-Regnier, Aurelie; Millot, Jean-Marc; Gorisse, Marie-Claude; Delvincourt, Chantal; Prevost, Alain

    2007-09-01

    Expression of three major resistance genes MDR1, MRP1 and LRP was investigated in small cell lung cancer, non-small cell lung cancer and metastasis. Single biopsies of bronchoscopy from 73 patients were performed to investigate expression of these three resistance genes by reverse transcriptase-polymerase chain reaction. Relations between gene expression and patient age, smoking status, histology, and chemotherapy were evaluated. A more frequent expression of MDR1 (77 versus 66%), MRP1 (91 versus 72%) and LRP (77 versus 63%) genes was detected in the malignant biopsies than in the non-malignant, respectively. In the metastasis biopsies, expression of these genes was markedly increased. No significant difference was observed between specimens before and after chemotherapy. Biopsies from progressing cancer showed higher MDR1, MRP1 and LRP gene expression. In conclusion, these data reveal a major role of MRP1 in intrinsic resistance and the high gene expression of MDR1 and MRP1 in relapsed diseases.

  1. Identification of galectin-1 as a novel mediator for chemoresistance in chronic myeloid leukemia cells.

    Science.gov (United States)

    Luo, Wu; Song, Li; Chen, Xi-Lei; Zeng, Xiang-Feng; Wu, Jian-Zhang; Zhu, Cai-Rong; Huang, Tao; Tan, Xiang-Peng; Lin, Xiao-Mian; Yang, Qi; Wang, Ji-Zhong; Li, Xiao-Kun; Wu, Xiao-Ping

    2016-05-01

    Multidrug resistance protein-1 (MDR1) has been proven to be associated with the development of chemoresistance to imatinib (Glivec, STI571) which displays high efficacy in treatment of BCR-ABL-positive chronic myelogenous leukemia (CML). However, the possible mechanisms of MDR1 modulation in the process of the resistance development remain to be defined. Herein, galectin-1 was identified as a candidate modulator of MDR1 by proteomic analysis of a model system of leukemia cell lines with a gradual increase of MDR1 expression and drug resistance. Coincidently, alteration of galectin-1 expression triggers the change of MDR1 expression as well as the resistance to the cytotoxic drugs, suggesting that augment of MDR1 expression engages in galectin-1-mediated chemoresistance. Moreover, we provided the first data showing that NF-κB translocation induced by P38 MAPK activation was responsible for the modulation effect of galectin-1 on MDR1 in the chronic myelogenous leukemia cells. Galectin-1 might be considered as a novel target for combined modality therapy for enhancing the efficacy of CML treatment with imatinib. PMID:27050374

  2. Pharmacogenomic Characterization of Cytotoxic Compounds from Salvia officinalis in Cancer Cells.

    Science.gov (United States)

    Kadioglu, Onat; Efferth, Thomas

    2015-04-24

    Salvia officinalis is used as a dietary supplement with diverse medicinal activity (e.g. antidiabetic and antiatherosclerotic effects). The plant also exerts profound cytotoxicity toward cancer cells. Here, we investigated possible modes of action to explain its activity toward drug-resistant tumor cells. Log10IC50 values of two constituents of S. officinalis (ursolic acid, pomolic acid) were correlated to the expression of ATP-binding cassette (ABC) transporters (P-glycoprotein/ABCB1/MDR1, MRP1/ABCC1, BCRP/ABCG2) and epidermal growth factor receptor (EGFR) or mutations in RAS oncogenes and the tumor suppressor gene TP53 of the NCI panel of cell lines. Gene expression profiles predicting sensitivity and resistance of tumor cells to these compounds were determined by microarray-based mRNA expressions, COMPARE, and hierarchical cluster analyses. Furthermore, the binding of both plant acids to key molecules of the NF-κB pathway (NF-κB, I-κB, NEMO) was analyzed by molecular docking. Neither expression nor mutation of ABC transporters, oncogenes, or tumor suppressor genes correlated with log10IC50 values for ursolic acid or pomolic acid. In microarray analyses, many genes involved in signal transduction processes correlated with cellular responsiveness to these compounds. Molecular docking indicated that the two plant acids strongly bound to target proteins of the NF-κB pathway with even lower free binding energies than the known NF-κB inhibitor MG-132. They interacted more strongly with DNA-bound NF-κB than free NF-κB, pointing to inhibition of DNA binding by these compounds. In conclusion, the lack of cross-resistance to classical drug resistance mechanisms (ABC-transporters, oncogenes, tumor suppressors) may indicate a promising role of the both plant acids for cancer chemotherapy. Genes involved in signal transduction may contribute to the sensitivity or resistance of tumor cells to ursolic and pomolic acids. Ursolic and pomolic acid may target different

  3. Detection of heterozygous MDR1 nt230(del4) mutation in a mixed-breed dog: case report of possible doxorubicin toxicosis

    OpenAIRE

    Monobe MM; Lunsford KV; Araújo Jr JP; Bulla C

    2013-01-01

    Marina Mitie Monobe,1 Kari V Lunsford,2 João Pessoa Araújo Jr,3 Camilo Bulla41Department of Veterinary Clinics, School of Veterinary Medicine and Animal Science, Sao Paulo State University, Botucatu, Brazil; 2Department of Clinical Sciences and Animal Health Center, College of Veterinary Medicine, Mississippi State University, MS, USA; 3Department of Microbiology and Immunology, Biosciences Institute, Sao Paulo State University, Botucatu, Brazil; 4Department of Pathobiology and ...

  4. Detection of heterozygous MDR1 nt230(del4) mutation in a mixed-breed dog: case report of possible doxorubicin toxicosis

    OpenAIRE

    Bulla, Camilo

    2013-01-01

    Marina Mitie Monobe,1 Kari V Lunsford,2 João Pessoa Araújo Jr,3 Camilo Bulla41Department of Veterinary Clinics, School of Veterinary Medicine and Animal Science, Sao Paulo State University, Botucatu, Brazil; 2Department of Clinical Sciences and Animal Health Center, College of Veterinary Medicine, Mississippi State University, MS, USA; 3Department of Microbiology and Immunology, Biosciences Institute, Sao Paulo State University, Botucatu, Brazil; 4Department of Pathobiol...

  5. Functional detection of MDR1/P170 and MRP/P190-mediated multidrug resistance in tumour cells by flow cytometry

    OpenAIRE

    Feller, N; Kuiper, C. M.; Lankelma, J.; Ruhdal, J. K.; Scheper, R J; Pinedo, H. M.; Broxterman, H. J.

    1995-01-01

    Multidrug resistance (MDR) in tumour cells is often caused by the overexpression of the plasma membrane drug transporter P-glycoprotein (P-gp) or the recently discovered multidrug resistance-associated protein (MRP). In this study we investigated the specificity and sensitivity of the fluorescent probes rhodamine 123 (R123), daunorubicin (DNR) and calcein acetoxymethyl ester (calcein-AM) in order to detect the function of the drug transporters P-gp and MRP, using flow cytometry. The effects o...

  6. Are altered pHi and membrane potential in hu MDR 1 transfectants sufficient to cause MDR protein-mediated multidrug resistance?

    OpenAIRE

    1996-01-01

    Multidrug resistance (MDR) mediated by overexpression of the MDR protein (P-glycoprotein) has been associated with intracellular alkalinization, membrane depolarization, and other cellular alterations. However, virtually all MDR cell lines studied in detail have been created via protocols that involve growth on chemotherapeutic drugs, which can alter cells in many ways. Thus it is not clear which phenotypic alterations are explicitly due to MDR protein overexpression alone. To more precisely ...

  7. Specific myeloprotection via multidrug resistance 1 gene controlled by aminopeptidase N myeloid promoter

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In the treatment of tumor patients introduction of multidrug resistance genes into hematopoietic cells has been reported as an approach for reducing myelotoxicity created by antitumor drugs. However, the nonspecific expression of the genes can also increase the chemoresistance of the tumor cells invaded into bone marrow, which influences seriously the effectiveness of chemotherapy. In this study, a new strategy is described for specific myeloprotection. The recombinant retroviral vector containing multidrug resistance 1 (MDR1) gene regulated by aminopeptidase N (APN) myeloid promoter was constructed and then introduced into myeloblastic cells KG1a and tumor cell line BEL7402. The specific transcript of MDR1 was detected in KG1a cells transduced with MDR1 gene and rhodamine 123 was effectively extruded by Pgp, the protein of MDR1 gene. The resistance elevated markedly by 10.6, 10.4, 11.2, 4.2 and 14.2 folds in MDR1 gene-transduced KG1a cells to chemotherapeutic drugs such as cochicine, VP-16, vincristine, doxorubi- cin and paclitaxel, respectively. In contrast, the chemoresistance had no significant changes in BEL7402 cells transduced with MDR1 gene. Expression of MDR1 directed by APN myeloid promoter resulted in myelospecific protection during the killing of tumor cells treated with antitumor drugs. The study would provide a new mean for circumventing myelosuppression of tumor patients undergoing chemotherapy.

  8. Differential effects of Th1, monocyte/macrophage and Th2 cytokine mixtures on early gene expression for molecules associated with metabolism, signaling and regulation in central nervous system mixed glial cell cultures

    Directory of Open Access Journals (Sweden)

    Studzinski Diane

    2009-01-01

    Full Text Available Abstract Background Cytokines secreted by immune cells and activated glia play central roles in both the pathogenesis of and protection from damage to the central nervous system (CNS in multiple sclerosis (MS. Methods We have used gene array analysis to identify the initial direct effects of cytokines on CNS glia by comparing changes in early gene expression in CNS glial cultures treated for 6 hours with cytokines typical of those secreted by Th1 and Th2 lymphocytes and monocyte/macrophages (M/M. Results In two previous papers, we summarized effects of these cytokines on immune-related molecules, and on neural and glial related proteins, including neurotrophins, growth factors and structural proteins. In this paper, we present the effects of the cytokines on molecules involved in metabolism, signaling and regulatory mechanisms in CNS glia. Many of the changes in gene expression were similar to those seen in ischemic preconditioning and in early inflammatory lesions in experimental autoimmune encephalomyelitis (EAE, related to ion homeostasis, mitochondrial function, neurotransmission, vitamin D metabolism and a variety of transcription factors and signaling pathways. Among the most prominent changes, all three cytokine mixtures markedly downregulated the dopamine D3 receptor, while Th1 and Th2 cytokines downregulated neuropeptide Y receptor 5. An unexpected finding was the large number of changes related to lipid metabolism, including several suggesting a switch from diacylglycerol to phosphatidyl inositol mediated signaling pathways. Using QRT-PCR we validated the results for regulation of genes for iNOS, arginase and P glycoprotein/multi-drug resistance protein 1 (MDR1 seen at 6 hours with microarray. Conclusion Each of the three cytokine mixtures differentially regulated gene expression related to metabolism and signaling that may play roles in the pathogenesis of MS, most notably with regard to mitochondrial function and neurotransmitter

  9. Molecular mechanism of glucocorticoid resistance in inflammatory bowel disease

    Institute of Scientific and Technical Information of China (English)

    Sara De Iudicibus; Raffaella Franca; Stefano Martelossi; Alessandro Ventura; Giuliana Decorti

    2011-01-01

    suggested as other possible candidates of interest that could play a role in the observed inter-individual differences in efficacy and toxicity. The best-characterized example is the drug efflux pump P-glycoprotein, a membrane transporter that extrudes GCs from cells, thereby lowering their intracellu-lar concentration. This protein is encoded by the ABCB1/MDR1 gene; this gene presents different known polymor-phic sites that can influence its expression and function. This editorial reviews the current knowledge on this topic and underlines the role of genetics in predicting GC clini-cal response. The ambitious goal of pharmacogenomic studies is to adapt therapies to a patient’s specific genetic background, thus improving on efficacy and safety rates.

  10. Multidrug resistance in ocular melanoma.

    OpenAIRE

    McNamara, M.; Clynes, M.; Dunne, B; NicAmhlaoibh, R; Lee, W. R.; Barnes, C; Kennedy, S M

    1996-01-01

    AIMS/BACKGROUND: Metastatic disease in patients with ocular melanoma is resistant to chemotherapy. One of the main mechanisms of modulating multidrug resistance is the expression of the multidrug resistance gene 1 (MDR1) product (p-glycoprotein) by tumour cells. The purpose of this study was to evaluate the frequency of expression of the MDR1 gene in ocular melanoma whose primary treatment was surgical excision or enucleation. METHODS: Twelve recent ocular melanomas were received fresh, snap ...

  11. Effects of hypoxia on expression of a panel of stem cell and chemosensitivity markers in glioblastoma cell line-derived spheroids

    DEFF Research Database (Denmark)

    Kolenda, Jesper; Jensen, Stine Skov; Aaberg-Jessen, Charlotte;

    immunohistochemical panel included hypoxia (HIF-1α, HIF-2α), proliferation (Ki-67) and stem cell (CD133, nestin, podoplanin, Bmi-1, Sox-2) markers as well as markers related to chemosensitivity (MGMT, MDR-1, TIMP-1, Lamp-1). Since spheroids derived in hypoxia were smaller than in normoxia, a set of experiments...

  12. Functional study of the novel multidrug resistance gene HA117 and its comparison to multidrug resistance gene 1

    Directory of Open Access Journals (Sweden)

    Chen Tingfu

    2010-07-01

    Full Text Available Abstract Background The novel gene HA117 is a multidrug resistance (MDR gene expressed by all-trans retinoic acid-resistant HL-60 cells. In the present study, we compared the multidrug resistance of the HA117 with that of the classical multidrug resistance gene 1 (MDR1 in breast cancer cell line 4T1. Methods Transduction of the breast cancer cell line 4T1 with adenoviral vectors encoding the HA117 gene and the green fluorescence protein gene (GFP (Ad-GFP-HA117, the MDR1 and GFP (Ad-GFP-MDR1 or GFP (Ad-GFP was respectively carried out. The transduction efficiency and the multiplicity of infection (MOI were detected by fluorescence microscope and flow cytometry. The transcription of HA117 gene and MDR1 gene were detected by reverse transcription polymerase chain reaction (RT-PCR. Western blotting analysis was used to detect the expression of P-glycoprotein (P-gp but the expression of HA117 could not be analyzed as it is a novel gene and its antibody has not yet been synthesized. The drug-excretion activity of HA117 and MDR1 were determined by daunorubicin (DNR efflux assay. The drug sensitivities of 4T1/HA117 and 4T1/MDR1 to chemotherapeutic agents were detected by Methyl-Thiazolyl-Tetrazolium (MTT assay. Results The transducted efficiency of Ad-GFP-HA117 and Ad-GFP-MDR1 were 75%-80% when MOI was equal to 50. The transduction of Ad-GFP-HA117 and Ad-GFP-MDR1 could increase the expression of HA117 and MDR1. The drug resistance index to Adriamycin (ADM, vincristine (VCR, paclitaxel (Taxol and bleomycin (BLM increased to19.8050, 9.0663, 9.7245, 3.5650 respectively for 4T1/HA117 and 24.2236, 11.0480, 11.3741, 0.9630 respectively for 4T1/MDR1 as compared to the control cells. There were no significant differences in drug sensitivity between 4T1/HA117 and 4T1/MDR1 for the P-gp substrates (ADM, VCR and Taxol (P Conclusions These results confirm that HA117 is a strong MDR gene in both HL-60 and 4T1 cells. Furthermore, our results indicate that the MDR

  13. Multi-drug resistance 1 genetic polymorphism and prediction of chemotherapy response in Hodgkin's Lymphoma

    OpenAIRE

    Haddadin William J; Matalka Ismail I; Alzoubi Karem H; Khabour Omar F.; Alshogran Osama Y; Mhaidat Nizar M; Mahasneh Ibraheem O; Aldaher Ahmad N

    2011-01-01

    Abstract Background The human multi-drug resistance gene (MDR1), which encodes the major trans-membrane transporter P-glycoprotein (P-gp), was found to be associated with susceptibility to cancer and response to chemotherapy. The C3435T Polymorphism of MDR1 gene was correlated with expression levels and functions of P-gp. Here, we studied the association between MDR1 C3435T polymorphism and susceptibility to Hodgkin lymphoma (HL) and patient's response to ABVD chemotherapy regimen. Methods a ...

  14. Role of p-glycoprotein expression in predicting response to neoadjuvant chemotherapy in breast cancer-a prospective clinical study

    Directory of Open Access Journals (Sweden)

    Bhatia Ashima

    2005-09-01

    Full Text Available Abstract Background Neoadjuvant chemotherapy (NACT is an integral part of multi-modality approach in the management of locally advanced breast cancer. It is vital to predict response to chemotherapy in order to tailor the regime for a particular patient. The prediction would help in avoiding the toxicity induced by an ineffective chemotherapeutic regime in a non-responder and would also help in the planning of an alternate regime. Development of resistance to chemotherapeutic agents is a major problem and one of the mechanisms considered responsible is the expression of 170-k Da membrane glycoprotein (usually referred to as p-170 or p-glycoprotein, which is encoded by multidrug resistance (MDR1 gene. This glycoprotein acts as an energy dependent pump, which actively extrudes certain families of chemotherapeutic agents from the cells. The expression of p-glycoprotein at initial presentation has been found to be associated with refractoriness to chemotherapy and a poor outcome. Against this background a prospective study was conducted using C219 mouse monoclonal antibody specific for p-glycoprotein to ascertain whether pretreatment detection of p-glycoprotein expression could be utilized as a reliable predictor of response to neoadjuvant chemotherapy in patients with breast cancer. Patients and methods Fifty cases of locally advanced breast cancer were subjected to trucut® biopsy and the tissue samples were evaluated immunohistochemically for p-glycoprotein expression and ER, PR status. The response to neoadjuvant chemotherapy was assessed clinically and by using ultrasound after three cycles of FAC regime (cyclophosphamide 600 mg/m2, Adriamycin 50 mg/m2, 5-fluorourail 600 mg/m2 at an interval of three weeks. The clinical response was correlated with both the pre and post chemotherapy p-glycoprotein expression. Descriptive studies were performed with SPSS version 10. The significance of correlation between tumor response and p

  15. Effects of Methylmercury Contained in a Diet Mimicking the Wayana Amerindians Contamination through Fish Consumption: Mercury Accumulation, Metallothionein Induction, Gene Expression Variations, and Role of the Chemokine CCL2

    Directory of Open Access Journals (Sweden)

    Daniel Brèthes

    2012-06-01

    Full Text Available Methylmercury (MeHg is a potent neurotoxin, and human beings are mainly exposed to this pollutant through fish consumption. We addressed the question of whether a diet mimicking the fish consumption of Wayanas Amerindians from French Guiana could result in observable adverse effects in mice. Wayanas adult men are subjected to a mean mercurial dose of 7 g Hg/week/kg of body weight. We decided to supplement a vegetarian-based mice diet with 0.1% of lyophilized Hoplias aimara fish, which Wayanas are fond of and equivalent to the same dose as that afflicting the Wayanas Amerindians. Total mercury contents were 1.4 ± 0.2 and 5.4 ± 0.5 ng Hg/g of food pellets for the control and aimara diets, respectively. After 14 months of exposure, the body parts and tissues displaying the highest mercury concentration on a dry weight (dw basis were hair (733 ng/g and kidney (511 ng/g, followed by the liver (77 ng/g. Surprisingly, despite the fact that MeHg is a neurotoxic compound, the brain accumulated low levels of mercury (35 ng/g in the cortex. The metallothionein (MT protein concentration only increased in those tissues (kidney, muscles in which MeHg demethylation had occurred. This can be taken as a molecular sign of divalent mercurial contamination since only Hg2+ has been reported yet to induce MT accumulation in contaminated tissues. The suppression of the synthesis of the chemokine CCL2 in the corresponding knockout (KO mice resulted in important changes in gene expression patterns in the liver and brain. After three months of exposure to an aimara-containing diet, eight of 10 genes selected (Sdhb, Cytb, Cox1, Sod1, Sod2, Mt2, Mdr1a and Bax were repressed in wild-type mice liver whereas none presented a differential expression in KO Ccl2/ mice. In the wild-type mice brain, six of 12 genes

  16. Functionalized silicon quantum dots tailored for targeted siRNA delivery

    International Nuclear Information System (INIS)

    For RNA interference (RNAi) mediated silencing of the ABCB1 gene in Caco-2 cells biocompatible luminescent silicon quantum dots (SiQDs) were developed to serve as self-tracking transfection tool for ABCB1 siRNA. While the 2-3 nm sized SiQD core exhibits green luminescence, the QD surfaces are completely saturated with covalently linked 2-vinylpyridine that may electrostatically bind siRNA. For down-regulating P-glycoprotein (Pgp) expression of the ABCB1 gene the SiQDs were complexed with siRNA. The cellular uptake and allocation of SiQD-siRNA complexes in Caco-2 cells were monitored using confocal laser scanning microscopy and transmission electron microscopy. The release of siRNA to the cytoplasm was verified through real-time PCR quantification of the reduced ABCB1 mRNA level. Additional evidence was obtained from time-resolved in situ fluorescence spectroscopic monitoring of the Pgp efflux dynamics in transfected Caco-2 cells which yielded significantly reduced transporter efficiencies for the Pgp substrate Rhodamine 123.

  17. Delivery of a survivin promoter-driven antisense survivin-expressing plasmid DNA as a cancer therapeutic: a proof-of-concept study

    Directory of Open Access Journals (Sweden)

    Lin KY

    2016-05-01

    Full Text Available Kun-Yuan Lin,1 Siao Muk Cheng,2 Shing-Ling Tsai,2 Ju-Ya Tsai,1 Chun-Hui Lin,1 Chun Hei Antonio Cheung1,2 1Department of Pharmacology, College of Medicine, National Cheng Kung University, Tainan, Taiwan, ROC; 2Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan, ROC Abstract: Survivin is a member of the inhibitor-of-apoptosis proteins family. It is overexpressed in many different cancer types but not in the differentiated normal tissue. In addition, overexpression of survivin promotes cancer cell survival and induces chemotherapeutic drug resistance, making it an attractive target for new anticancer interventions. Despite survivin being a promising molecular target for anticancer treatment, it is widely accepted that survivin is only a “semi-druggable” target. Therefore, it is important to develop a new strategy to target survivin for anticancer treatment. In this study, we constructed a novel survivin promoter-driven full-length antisense survivin (pSur/AS-Sur expression plasmid DNA. Promoter activity assay revealed that the activity of the survivin promoter of pSur/AS-Sur correlated with the endogenous expression of survivin at the transcriptional level in the transfected A549, MDA-MB-231, and PANC-1 cancer cells. Western blot analysis showed that liposomal delivery of pSur/AS-Sur successfully downregulated the expression of survivin in A549, MBA-MB-231, and PANC-1 cells in vitro. In addition, delivery of pSur/AS-Sur induced autophagy, caspase-dependent apoptosis, and caspase-independent apoptosis as indicated by the increased LC3B-II conversion, autophagosome formation, caspase-9/-3 and poly(ADP-ribose polymerase-1 cleavage, and apoptosis-inducing factor nuclear translocation in A549, MBA-MB-231, and PANC-1 cells. Importantly, liposomal delivery of pSur/AS-Sur was also capable of decreasing the proliferation of the survivin/MDR1 coexpressing multidrug-resistant KB-TAX50 cancer cells and

  18. RETROVIRAL MEDIATED EFFICIENT TRANSFER ANDEXPRESSION OF MULTIPLE DRUG RESISTANCE GENE TO HUMAN LEUKEMIC CELLS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective: To investigate retroviral-mediated transfer and expression of human multidrug resistance (MDR) gene MDR1 in leukemic cells. Methods: Human myeloid cells, K562 and NB4, were infected by MDR retrovirus from the producer PA317/HaMDR, and the resistant cells were selected with cytotoxic drug. The transfer and expression of MDR1 gene was analyzed by using polymerase chain reaction (PCR), flow cytometry (FCM) and semisolid colonies cultivation. Results: The resistant cells, K562/MDR and NB4/MDR, in which integration of the exogenous MDR1 gene was confirmed by PCR analysis, displayed a typical MDR phenotype. The expression of MDR1 transgene was detected on truncated as well as full-length transcripts. Moreover, the resistant cells were P-glycoprotein postiive at 78.0% to 98.7% analyzed with FCM. The transduction efficieny in K562 cells was studied on suspension cultures and single-cell colonies. The transduction was more efficient in coculture system (67.9%~ 72.5%) than in supernatant system (33.1%~ 46.8%), while growth factors may improve the efficiency. Conclusion: Retrovirus could allow a functional transfer and expression of MDR1 gene in human leukemia cells, and MDR1 might act as a dominant selectable gene for coexpression with the genes of interest in gene therapy.

  19. Association between Genetic Polymorphism of Multidrug Resistance 1 Gene and Sasang Constitutions

    OpenAIRE

    Hyun-Ju Kim; Seung Yeon Hwang; Ju-Ho Kim; Hye-Jung Park; Sang-Gyu Lee; Si-Woo Lee; Jong-Cheon Joo; Yun-Kyung Kim

    2009-01-01

    Multidrug resistance 1 (MDR1) is a gene that expresses P-glycoprotein (P-gp), a drug transporter protein. Genetic polymorphisms of MDR1 can be associated with Sasang constitutions because Sasang constitutional medicine (SCM) prescribes different drugs according to different constitutions. A Questionnaire for Sasang Constitution Classification II (QSCC II) was used to diagnose Sasang constitutions. Two hundred and seven healthy people whose Sasang constitutions had been identified were tested....

  20. [18F]FDG is not transported by P-glycoprotein and breast cancer resistance protein at the rodent blood–brain barrier

    International Nuclear Information System (INIS)

    Introduction: Transport of 2-[18F]fluoro-2-deoxy-D-glucose ([18F]FDG) by the multidrug efflux transporters P-glycoprotein (ABCB1) and breast cancer resistance protein (ABCG2) at the blood–brain barrier (BBB) may confound the interpretation of [18F]FDG brain PET data. Aim of this study was to assess the influence of ABCB1 and ABCG2 at the BBB on brain distribution of [18F]FDG in vivo by performing [18F]FDG PET scans in wild-type and transporter knockout mice and by evaluating changes in [18F]FDG brain distribution after transporter inhibition. Methods: Dynamic small-animal PET experiments (60 min) were performed with [18F]FDG in groups of wild-type and transporter knockout mice (Abcb1a/b(−/−), Abcg2(−/−) and Abcb1a/b(−/−)Abcg2(−/−)) and in wild-type rats without and with i.v. pretreatment with the known ABCB1 inhibitor tariquidar (15 mg/kg, given at 2 h before PET). Blood was sampled from animals from the orbital sinus vein at the end of the PET scans and measured in a gamma counter. Brain uptake of [18F]FDG was expressed as the brain-to-blood radioactivity concentration ratio in the last PET time frame (Kb,brain). Results: Kb,brain values of [18F]FDG were not significantly different between different mouse types both without and with tariquidar pretreatment. The blood-to-brain transfer rate constant of [18F]FDG was significantly lower in tariquidar-treated as compared with vehicle-treated rats (0.350 ± 0.025 mL/min/g versus 0.416 ± 0.024 mL/min/g, p = 0.026, paired t-test) but Kb,brain values were not significantly different between both rat groups. Conclusion: Our results show that [18F]FDG is not transported by Abcb1 at the mouse and rat BBB in vivo. In addition we found no evidence for Abcg2 transport of [18F]FDG at the mouse BBB. Advances in knowledge and implications for patient care: Our findings imply that functional activity of ABCB1 and ABCG2 at the BBB does not need to be taken into account when interpreting brain [18F]FDG PET data

  1. Co-cultivation of murine BMDCs with 67NR mouse mammary carcinoma cells give rise to highly drug resistant cells

    Directory of Open Access Journals (Sweden)

    Zänker Kurt S

    2011-06-01

    Full Text Available Abstract Background Tumor tissue resembles chronically inflamed tissue. Since chronic inflammatory conditions are a strong stimulus for bone marrow-derived cells (BMDCs it can be assumed that recruitment of BMDCs into cancer tissue should be a common phenomenon. Several data have outlined that BMDC can influence tumor growth and metastasis, e.g., by inducing a paracrine acting feedback loop in tumor cells. Likewise, cell fusion and horizontal gene transfer are further mechanisms how BMDCs can trigger tumor progression. Results Hygromycin resistant murine 67NR-Hyg mammary carcinoma cells were co-cultivated with puromycin resistant murine BMDCs from Tg(GFPU5Nagy/J mice. Isolation of hygromycin/puromycin resistant mBMDC/67NR-Hyg cell clones was performed by a dual drug selection procedure. PCR analysis revealed an overlap of parental markers in mBMDC/67NR-Hyg cell clones, suggesting that dual resistant cells originated by cell fusion. By contrast, both STR and SNP data analysis indicated that only parental 67NR-Hyg alleles were found in mBMDC/67NR-Hyg cell clones favoring horizontal gene transfer as the mode of origin. RealTime-PCR-array analysis showed a marked up-regulation of Abcb1a and Abcb1b ABC multidrug transporters in mBMDC/67NR-Hyg clones, which was verified by Western Blot analysis. Moreover, the markedly increased Abcb1a/Abcb1b expression was correlated to an efficient Rhodamine 123 efflux, which was completely inhibited by verapamil, a well-known Abcb1a/Abcb1b inhibitor. Likewise, mBMDCs/67NR-Hyg clones revealed a marked resistance towards chemotherapeutic drugs including 17-DMAG, doxorubicin, etoposide and paclitaxel. In accordance to Rhodamine 123 efflux data, chemotherapeutic drug resistance of mBMDC/67NR-Hyg cells was impaired by verapamil mediated blockage of Abc1a/Abcb1b multidrug transporter function. Conclusion Co-cultivation of mBMDCs and mouse 67NR-Hyg mammary carcinoma cells gave rise to highly drug resistant cells. Even

  2. Enhanced active metabolite generation and platelet inhibition with prasugrel compared to clopidogrel regardless of genotype in thienopyridine metabolic pathways.

    Science.gov (United States)

    Braun, Oscar Ö; Angiolillo, Dominick J; Ferreiro, Jose L; Jakubowski, Joseph A; Winters, Kenneth J; Effron, Mark B; Duvvuru, Suman; Costigan, Timothy M; Sundseth, Scott; Walker, Joseph R; Saucedo, Jorge F; Kleiman, Neal S; Varenhorst, Christoph

    2013-12-01

    Clopidogrel response varies according to the presence of genetic polymorphisms. The CYP2C19*2 allele has been associated with impaired response; conflicting results have been reported for CYP2C19*17, ABCB1, and PON1 genotypes. We assessed the impact of CYP2C19, PON1, and ABCB1 polymorphisms on clopidogrel and prasugrel pharmacodynamic (PD) and pharmacokinetic (PK) parameters. Aspirin-treated patients (N=194) with coronary artery disease from two independent, prospective, randomised, multi-centre studies comparing clopidogrel (75 mg) and prasugrel (10 mg) were genotyped and classified by predicted CYP2C19 metaboliser phenotype (ultra metabolisers [UM] = *17 carriers; extensive metabolisers [EM] = *1/1 homozygotes; reduced metabolisers [RM] = *2 carriers). ABCB1 T/T and C/T polymorphisms and PON1 A/A, A/G and G/G polymorphisms were also genotyped. PD parameters were assessed using VerifyNow® P2Y12 and vasodilator stimulated phosphoprotein (VASP) expressed as platelet reactivity index (PRI) after 14 days of maintenance dosing. Clopidogrel and prasugrel active metabolite (AM) exposure was calculated in a cohort of 96 patients. For clopidogrel, genetic variants in CYP2C19, but not ABCB1 or PON1, affected PK and PD. For prasugrel, none of the measured genetic variants affected PK or PD. Compared with clopidogrel, platelet inhibition with prasugrel was greater even in the CYP2C19 UM phenotype. Prasugrel generated more AM and achieved greater platelet inhibition than clopidogrel irrespective of CYP2C19, ABCB1, and PON1 polymorphisms. The lack of effect from genetic variants on prasugrel AM generation or antiplatelet activity is consistent with previous studies in healthy volunteers and is consistent with improved efficacy in acute coronary syndrome patients managed with percutaneous coronary intervention. PMID:24009042

  3. Synthesis and bioevaluation of novel benzodipyranone derivatives as P-glycoprotein inhibitors for multidrug resistance reversal agents.

    Science.gov (United States)

    Chen, Chien-Yu; Liu, Nai-Yu; Lin, Hui-Chang; Lee, Chih-Yu; Hung, Chin-Chuan; Chang, Chih-Shiang

    2016-08-01

    Multidrug resistance (MDR) is a phenomenon in which cells become resistant to structurally and mechanistically unrelated drugs, and it is one of the emerging problems in cancer therapy today. The relation between overexpression of the ABC transporter subfamily B member 1 (ABCB1/P-glycoprotein) and resistant cancers has been well characterized. In the present study, we successfully synthesized 52 novel benzodipyranone analogs and evaluated for their P-gp inhibitory activity in a P-gp transfected cell line, ABCB1/Flp-In™-293. Among these derivatives, 5a bearing on the 3-methylphenyl substituent, displayed the most potent P-gp inhibitory activity, which can enable the increase of the intracellular accumulation of P-gp substrate Calcein-AM. 5a exhibited more potency on promoted anticancer drugs cytotoxicity by reversing P-gp-mediated drug resistance in both ABCB1/Flp-In™-293 and KBvin cell lines. In particular, the compound 5a sensitized ABCB1/Flp-In™-293 cells toward paclitaxel, vincristine, and doxorubicin by 16.1, 21.0, and 1.6-fold at 10 μM, respectively. Further, 5a dramatically sensitized the resistant cell line KBvin toward paclitaxel and vincristine by 23.1 and 29.7-fold at 10 μM, respectively. It's possible that its mechanism of MDR inhibition can restore the intracellular accumulation of drugs and eventually chemosensitize cancer cells to anticancer drugs and reduce ABCB1 mRNA expression level. PMID:27131064

  4. Thyroid Hormone and P-Glycoprotein in Tumor Cells

    Directory of Open Access Journals (Sweden)

    Paul J. Davis

    2015-01-01

    Full Text Available P-glycoprotein (P-gp; multidrug resistance pump 1, MDR1; ABCB1 is a plasma membrane efflux pump that when activated in cancer cells exports chemotherapeutic agents. Transcription of the P-gp gene (MDR1 and activity of the P-gp protein are known to be affected by thyroid hormone. A cell surface receptor for thyroid hormone on integrin αvβ3 also binds tetraiodothyroacetic acid (tetrac, a derivative of L-thyroxine (T4 that blocks nongenomic actions of T4 and of 3,5,3′-triiodo-L-thyronine (T3 at αvβ3. Covalently bound to a nanoparticle, tetrac as nanotetrac acts at the integrin to increase intracellular residence time of chemotherapeutic agents such as doxorubicin and etoposide that are substrates of P-gp. This action chemosensitizes cancer cells. In this review, we examine possible molecular mechanisms for the inhibitory effect of nanotetrac on P-gp activity. Mechanisms for consideration include cancer cell acidification via action of tetrac/nanotetrac on the Na+/H+ exchanger (NHE1 and hormone analogue effects on calmodulin-dependent processes and on interactions of P-gp with epidermal growth factor (EGF and osteopontin (OPN, apparently via αvβ3. Intracellular acidification and decreased H+ efflux induced by tetrac/nanotetrac via NHE1 is the most attractive explanation for the actions on P-gp and consequent increase in cancer cell retention of chemotherapeutic agent-ligands of MDR1 protein.

  5. EXPRESSION OF P-GLYCOPRITEIN AND MUTANT P53, EPIDERMAL GROWTH FACTOR RECEPTOR IN HUMAN PRIMARY TRANSITIONAL CELL CARCINOMAS OF BLADDER%原发性膀胱移行细胞癌Pgp与突变p53蛋白、EGFR的相互关系 原发性膀胱移行细胞癌Pgp与突变p53蛋白、EGFR的相互关系

    Institute of Scientific and Technical Information of China (English)

    周辉良; 罗义麒; 曹林升; 张声

    2001-01-01

    The study investigates clinical signif icance and the interrelationship between expression of multi-drug resistance gen e (MDR1) product (P-glycoprotein Pgp)and mutant p53,epidermal growth factor rece ptor (EGFR) in human primary bladder transitional cell carcinomas(TCCs).Methods:107 human primary bladder TCCs of previously untreated p atients were analyzed for expression of Pgp,Mutant p53 and EGFR by means of SP i mmunohischemistry (IHC).The mouse's monoclonal antibodies of JSB1,DO-7 and 31G7 were carried out to detected the antigens of Pgp,p53 and EGFR,respectively.Results:Pgp,p53 and EGFR were present in 63.6%,72.9% and 66.4% of TCC s.The expressions of Pgp,p53 or EGFR were significantly correlated with the grad ,stage and recurrence after post-operative intravesical chemotherapy.The express ions of Pgp were strongly related to the expression of mutant p53 and EGFR (Pgp/ p53,P<0.01;Pgp/EGFR,P<0.01).Conclusions:Overexpression of Pgp ,mutant p53 and EGFR can be used as the important markers of aggressiveness and prognosis of TCCs.The expression of Pgp could be modulated by mutant p53 and EG FR,as is found in other tumors.%探讨mdr1基因表达产物Pgp与突变p53蛋白、EGFR是否存在相 关性及其临床意义。方法:采用免疫组化SP法,检测107例原发性膀胱移行细胞癌中Pgp、突 变p53蛋白、EGFR表达情况。结果:Pgp、突变p53蛋白、EGFR的阳性表达率分别为63.6%,72 .9%和66.4%,三者的过表达均与膀胱癌的病理分级、分期和术后的复发有关;相关性研究显 示Pgp表达与突变p53蛋白和EGFR的表达密切相关(P<0.01)。结论:Pgp、突变p53蛋白 和EGFR过表达不仅是判定原发性膀胱移行细胞癌恶性程度和预后的重要指标,而且提示原 发性膀胱移行细胞癌中Pgp的表达可能与其他肿瘤一样,受到p53和EGFR等的调控。

  6. Express web application development

    CERN Document Server

    Yaapa, Hage

    2013-01-01

    Express Web Application Development is a practical introduction to learning about Express. Each chapter introduces you to a different area of Express, using screenshots and examples to get you up and running as quickly as possible.If you are looking to use Express to build your next web application, ""Express Web Application Development"" will help you get started and take you right through to Express' advanced features. You will need to have an intermediate knowledge of JavaScript to get the most out of this book.

  7. Facial Expression Recognition

    OpenAIRE

    Neeta Sarode; Prof. Shalini Bhatia

    2010-01-01

    Facial expression analysis is rapidly becoming an area of intense interest in computer science and human-computer interaction design communities. The most expressive way humans display emotions is through facial expressions. In this paper a method is implemented using 2D appearance-based local approach for the extraction of intransient facial features and recognition of four facial expressions. The algorithm implements Radial Symmetry Transform and further uses edge projection analysis for fe...

  8. After Effects expressions

    CERN Document Server

    Geduld, Marcus

    2013-01-01

    Put the power of Expressions to work in your animations with controls and efficiencies impossible to achieve with traditional keyframing techniques. No programming skills are required. Foundation concepts and skills orient the new designer and serve as a handy reference to the experienced one. Basics of creating expressions, variables, commands, and expression helpers precede the leap into javascript and math essentials for more advanced expressions that include randomness, physical simularions and 3D. Full color illustrations display the scripts and the resulti

  9. Extrachromosomal inducible expression

    NARCIS (Netherlands)

    Veltman, Douwe M; Van Haastert, Peter J M; Eichinger, L.; Rivero, F.

    2013-01-01

    Inducible expression systems are very convenient for proteins that induce strong side effects such as retardation of growth or development and are essential for the expression of toxic proteins. In this chapter we describe the doxycycline-inducible expression system, optimized for the controlled exp

  10. Comparison of the uptakes of {sup 99m}Tc-sestamibi and {sup 99m}Tc-tetrofosmin in cancer cell lines expressing multidrug resistance

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Jeong Ah; Chung, Shin Young; Seo, Myeng Rang; Kwak, Dong Suk; Ahm, Byeong Cheol; Lee, Kyu Bo; Lee, Jae Tae [Kyungpook National University School of Medicine, Taegu (Korea, Republic of)

    2003-06-01

    Cellular uptakes of {sup 99m}Tc-sestamibi(MIBI) and {sup 99m}Tc-tetrofosmin into cancer cell lines expressing multidrug resistance(MDR) were investigated and compared. The effects of verapamil and cyclosporin A, well-known multidrug resistant reversing agents, on cellular uptakes of both tracers were also compared. Doxorubicin-resistant HCT15/CL02 human colorectal cell and doxorubicin-resistant K562(Adr) and vincristin-resistant K562(Vcr) human leukemic cells were studied. RT-PCR analysis was used for the detection of mdr1 mRNA expression. MDR-reversal effects with verapamil and cyclosporine A were evaluated at different drug concentrations after incubation with MIBI and tetrofosimin for 1, 15, 30, 45 and 60 min, using single-cell suspensions at 1x10{sup 6} cells/ml incubated at 37 .deg. C. Radioactivity in supernatants and pellets were measured with gamma well counter. The cellular uptakes of MIBI and tetrofosmin in K562(Adr) and K562(Vcr) were lower than those of parental K562 cell. In HCT15/CL02 cells ad K562(Adr) cells, there were no significant difference in cellular uptakes of both tracers, but cellular uptake of MIBI was higher than that of tetrofosmin in K562(Vcr) cells. Coincubation with verapamil resulted in a increase in cellular uptakes of MIBI and tetrofosmin. Verapamil increased cellular uptakes of MIBI and tetrofosmin by HCT15/LC02 cell by 11.9- and 6.8-fold, by K562(Adr) cell by 14.3- and 8-fold and by K562(Vcr) cell by 7- and 5.7-fold in maximum, respectively. Cyclosporin A increased cellular uptakes of MIBI and tetrofosmin by HCT15/CL02 cell by 10- and 2.4-fold, by K562(Adr) cell by 44- and 13-fold and by K562(Vcr) cell by 18.8- and 11.8-fold in maximum, respectively. Taking together, MIBI and tetrofosmin are considered as suitable radiopharmaceuticals for detecting multidrug resistance. However, MIBI seems to be a better tracer than tetrofosmin for evaluating MDR reversal effect of the modulators. Since cellular uptakes of both tracers might

  11. Associations between ABCB1, CYP2A6, CYP2B6, CYP2D6, and CYP3A5 alleles in relation to efavirenz and nevirapine pharmacokinetics in HIV-infected individuals.

    NARCIS (Netherlands)

    Heil, S.G.; Ende, M.E. van der; Schenk, P.W.; Heiden, I. van der; Lindemans, J.; Burger, D.M.; Schaik, R.H. van

    2012-01-01

    BACKGROUND: Human immunodeficiency virus (HIV)-infected individuals show large interindividual variation in response to antiretroviral therapy. Efavirenz (EFV) and nevirapine (NVP) are nonnucleoside reverse transcriptase inhibitors, which are prescribed in combination with other antiretroviral thera

  12. Imaging and Targeted Therapy of Multidrug Resistance. Final Report

    International Nuclear Information System (INIS)

    One focus area of DOE Office of Science was the Imaging of Gene Expression in Health and Disease in real time in tissue culture, whole animals and ultimately patients. Investigators of the Molecular Imaging Group, Washington University Medical School, ascribed to this objective and a major focus of this group directly tied into the DOE program through their efforts targeting the multidrug resistance gene (MDR1). Our plans for continuation of the program were to extend and build on this line of investigation, incorporating new molecular tools into our methodology to selectively inhibit MDR1 gene expression with novel modulation strategies. Two approaches were to be pursued: (1) high throughput screening of compounds that disrupted mutant p53 transactivation of the MDR1 promoter, and (2) knockdown of MDR1 messenger RNA with retroviral-mediated delivery of small interfering RNA constructs. These would be combined with our continuing effort to synthesize ligands and examine structure-activity relationships of bis-salicylaldehydes labeled with gallium-68 to generate PET agents for imaging MDR1 P-glycoprotein function. We would be uniquely positioned to correlate therapeutic modulation of MDR1 gene expression and protein function in the same systems in vivo using PET and bioluminescence reporters. Use of animal models such as the mdr1a/1b(-/-) gene deleted mice would also have enabled refined analysis of modulation and tracer pharmacokinetics in vivo. Overall, this DOE program and resultant tools would enable direct monitoring of novel therapeutic strategies and the MDR phenotype in relation to gene expression and protein function in vivo.

  13. Holistic facial expression classification

    Science.gov (United States)

    Ghent, John; McDonald, J.

    2005-06-01

    This paper details a procedure for classifying facial expressions. This is a growing and relatively new type of problem within computer vision. One of the fundamental problems when classifying facial expressions in previous approaches is the lack of a consistent method of measuring expression. This paper solves this problem by the computation of the Facial Expression Shape Model (FESM). This statistical model of facial expression is based on an anatomical analysis of facial expression called the Facial Action Coding System (FACS). We use the term Action Unit (AU) to describe a movement of one or more muscles of the face and all expressions can be described using the AU's described by FACS. The shape model is calculated by marking the face with 122 landmark points. We use Principal Component Analysis (PCA) to analyse how the landmark points move with respect to each other and to lower the dimensionality of the problem. Using the FESM in conjunction with Support Vector Machines (SVM) we classify facial expressions. SVMs are a powerful machine learning technique based on optimisation theory. This project is largely concerned with statistical models, machine learning techniques and psychological tools used in the classification of facial expression. This holistic approach to expression classification provides a means for a level of interaction with a computer that is a significant step forward in human-computer interaction.

  14. Multidrug Resistance: Physiological Principles and Nanomedical Solutions

    OpenAIRE

    Kunjachan, Sijumon; Rychlik, Błażej; Storm,Gert; Kiessling, Fabian; Lammers, Twan

    2013-01-01

    Multidrug (MDR) resistance is a pathophysiological phenomenon employed by cancer cells which limits the prolonged and effective use of chemotherapeutic agents. MDR is primarily based on the over-expression of drug efflux pumps in the cellular membrane. Prominent examples of such efflux pumps, which belong to the ATP-binding cassette (ABC) superfamily of proteins, are Pgp (P-glycoprotein) and MRP (multidrug resistance-associated protein), nowadays officially known as ABCB1 and ABCC1. Over the ...

  15. Pleiotrophin Expression during Odontogenesis

    OpenAIRE

    Erlandsen, Heidi; Ames, Jennifer E.; Tamkenath, Amena; Mamaeva, Olga; Stidham, Katherine; Wilson, Mary E; Perez-Pinera, Pablo; Deuel, Thomas F.; Macdougall, Mary

    2012-01-01

    Pleiotrophin (PTN) is an extracellular matrix–associated growth factor and chemokine expressed in mesodermal and ectodermal cells. It plays an important role in osteoblast recruitment and differentiation. There is limited information currently available about PTN expression during odontoblast differentiation and tooth formation, and thus the authors aimed to establish the spatiotemporal expression pattern of PTN during mouse odontogenesis. Immortalized mouse dental pulp (MD10-D3, MD10-A11) an...

  16. Regular Expression Pocket Reference

    CERN Document Server

    Stubblebine, Tony

    2007-01-01

    This handy little book offers programmers a complete overview of the syntax and semantics of regular expressions that are at the heart of every text-processing application. Ideal as a quick reference, Regular Expression Pocket Reference covers the regular expression APIs for Perl 5.8, Ruby (including some upcoming 1.9 features), Java, PHP, .NET and C#, Python, vi, JavaScript, and the PCRE regular expression libraries. This concise and easy-to-use reference puts a very powerful tool for manipulating text and data right at your fingertips. Composed of a mixture of symbols and text, regular exp

  17. Regular expressions cookbook

    CERN Document Server

    Goyvaerts, Jan

    2009-01-01

    This cookbook provides more than 100 recipes to help you crunch data and manipulate text with regular expressions. Every programmer can find uses for regular expressions, but their power doesn't come worry-free. Even seasoned users often suffer from poor performance, false positives, false negatives, or perplexing bugs. Regular Expressions Cookbook offers step-by-step instructions for some of the most common tasks involving this tool, with recipes for C#, Java, JavaScript, Perl, PHP, Python, Ruby, and VB.NET. With this book, you will: Understand the basics of regular expressions through a

  18. Change in ATP-binding cassette B1/19, glutamine synthetase and alcohol dehydrogenase gene expression during root elongation in Betula pendula Roth and Alnus glutinosa L. Gaertn in response to leachate and leonardite humic substances.

    Science.gov (United States)

    Tahiri, Abdelghani; Delporte, Fabienne; Muhovski, Yordan; Ongena, Marc; Thonart, Philippe; Druart, Philippe

    2016-01-01

    Humic substances (HS) are complex and heterogeneous compounds of humified organic matter resulting from the chemical and microbiological decomposition of organic residues. HS have a positive effect on plant growth and development by improving soil structure and fertility. They have long been recognized as plant growth-promoting substances, particularly with regard to influencing nutrient uptake, root growth and architecture. The biochemical and molecular mechanisms through which HS influence plant physiology are not well understood. This study evaluated the bioactivity of landfill leachate and leonardite HS on alder (Alnus glutinosa L. Gaertn) and birch (Betula pendula Roth) during root elongation in vitro. Changes in root development were studied in relation to auxin, carbon and nitrogen metabolisms, as well as to the stress adaptive response. The cDNA fragments of putative genes encoding two ATP-binding cassette (ABC) transporters (ABCB1 and ABCB19) belonging to the B subfamily of plant ABC auxin transporters were cloned and sequenced. Molecular data indicate that HS and their humic acid (HA) fractions induce root growth by influencing polar auxin transport (PAT), as illustrated by the modulation of the ABCB transporter transcript levels (ABCB1 and ABCB19). There were also changes in alcohol dehydrogenase (ADH) and glutamine synthetase (GS) gene transcript levels in response to HS exposure. These findings confirmed that humic matter affects plant growth and development through various metabolic pathways, including hormonal, carbon and nitrogen metabolisms and stress response or signalization.

  19. Change in ATP-binding cassette B1/19, glutamine synthetase and alcohol dehydrogenase gene expression during root elongation in Betula pendula Roth and Alnus glutinosa L. Gaertn in response to leachate and leonardite humic substances.

    Science.gov (United States)

    Tahiri, Abdelghani; Delporte, Fabienne; Muhovski, Yordan; Ongena, Marc; Thonart, Philippe; Druart, Philippe

    2016-01-01

    Humic substances (HS) are complex and heterogeneous compounds of humified organic matter resulting from the chemical and microbiological decomposition of organic residues. HS have a positive effect on plant growth and development by improving soil structure and fertility. They have long been recognized as plant growth-promoting substances, particularly with regard to influencing nutrient uptake, root growth and architecture. The biochemical and molecular mechanisms through which HS influence plant physiology are not well understood. This study evaluated the bioactivity of landfill leachate and leonardite HS on alder (Alnus glutinosa L. Gaertn) and birch (Betula pendula Roth) during root elongation in vitro. Changes in root development were studied in relation to auxin, carbon and nitrogen metabolisms, as well as to the stress adaptive response. The cDNA fragments of putative genes encoding two ATP-binding cassette (ABC) transporters (ABCB1 and ABCB19) belonging to the B subfamily of plant ABC auxin transporters were cloned and sequenced. Molecular data indicate that HS and their humic acid (HA) fractions induce root growth by influencing polar auxin transport (PAT), as illustrated by the modulation of the ABCB transporter transcript levels (ABCB1 and ABCB19). There were also changes in alcohol dehydrogenase (ADH) and glutamine synthetase (GS) gene transcript levels in response to HS exposure. These findings confirmed that humic matter affects plant growth and development through various metabolic pathways, including hormonal, carbon and nitrogen metabolisms and stress response or signalization. PMID:26595095

  20. SALL4 as an Epithelial-Mesenchymal Transition and Drug Resistance Inducer through the Regulation of c-Myc in Endometrial Cancer.

    Directory of Open Access Journals (Sweden)

    Lei Liu

    Full Text Available SALL4 plays important roles in the development and progression of many cancers. However, the role and molecular mechanism of SALL4 in endometrial cancer remain elusive. In the present research, we have demonstrated that the expression of SALL4 was upregulated in endometrial cancer and correlated positively with tumor stage, metastases and poor survival of patients. The overexpression of SALL4 promoted the invasiveness in endometrial cancer cells, as indicated by the upregulation of mesenchymal cell marker N-cadherin and downregulation of