Synergistic Effect of Hyperthermia and Neferine on Reverse Multidrug Resistance in Adriamycin-resistant SGC7901/ADM Gastric Cancer Cells

Multidrug resistance（MDR） plays a major obstacle to successful gastric cancer chemotherapy.The purpose of this study was to investigate the MDR reversal effect and mechanisms of hyperthermia in combination with neferine（Nef） in adriamycin（ADM） resistant human SGC7901/ADM gastric cancer cells.The MDR cells were heated at 42℃ and 45℃ for 30 min alone or combined with 10 μg/mL Nef.The cytotoxic effect of ADM was evaluated by MTT assay.Cellular plasma membrane lipid fluidity was detected by fluorescence polarization technique.Intracellular accumulation of ADM was monitored with high performance liquid chromatography.Mdr-1 mRNA,P-glycoprotein（P-gp）,γH2AX expression and γH2AX foci formation were determined by real-time PCR,Western blot and immunocytochemical staining respectively.It was found that different heating methods induced different cytotoxic effects.Water submerged hyperthermia had the strongest cytotoxicity of ADM and Nef combined with hyperthermia had a synergistic cytotoxicity of ADM in the MDR cells.The water submerged hyperthermia increased the cell membrane fluidity.Both water submerged hyperthermia and Nef increased the intracellular accumulation of ADM.The water submerged hyperthermia and Nef down-regulated the expression of mdr-1 mRNA and P-gp.The water submerged hyperthermia could damage DNA and increase the γH2AX expression of SGC7901/ADM cells.The higher temperature was,the worse effect was.Our results show that combined treatment of hyperthermia with Nef can synergistically reverse MDR in human SGC7901/ADM gastric cancer cells.

Association of single nucleotide polymorphisms of brain-derived neurotrophic factor gene and multidrug resistance 1 gene to refractory epilepsy in Chinese Han children

BACKGROUND： There are two hypotheses for the underlying cause of refractory epilepsy： ＂target＂ and ＂transport＂. Studies have shown that brain-derived neurotrophic factor （BDNF） is over-expressed in refractory epilepsy. Multidrug resistance 1 （MDR1） gene encodes for P-glycoprotein, the primary ATP-binding cassette transporter in the human body. Some single nucleotide polymorphisms of the MDR1 gene have been associated with refractory epilepsy. OBJECTIVE： To investigate the association between BDNF gene C270T polymorphism and MDR1 T-129C polymorphism with refractory epilepsy in Chinese Han children through the use of polymerase chain reaction （PCR）-restriction fragment length polymorphism analysis. DESIGN, TIME AND SETTING： A case-control, genetic association study was performed at the Central Laboratory, Third Xiangya Hospital of Central South University from June 2005 to November 2007. PARTICIPANTS： A total of 84 cases of unrelated children with epilepsy, including 41 cases of refractory epilepsy and 43 cases of drug-responsive epilepsy, were enrolled. An additional 30 healthy, Chinese Han children, whose ages and gender matched the refractory epilepsy patients, were selected as normal controls. METHODS： Venous blood was collected and genomic DNA was extracted from the blood specimens. C270T polymorphism in BDNF gene and T-129C polymorphism in MDR1 gene were genotyped using PCR-restriction fragment length polymorphism analysis. Association analysis using the Ftest and Chi-square test was statistically performed between C270T polymorphism in BDNF gene and T-129C polymorphism in MDR1 gene and refractory epilepsy. MAIN OUTCOME MEASURES： The distribution of genotypes and allele frequencies of C270T polymorphism in BDNF gene and T-129C polymorphism in MDR1 gene. RESULTS： The distribution of CC, CT, and TT genotypes, as well as C and T allele frequencies, in the BDNF gene was not significantly different between the refractory epilepsy group, drug-responsive epilepsy group, or the normal control group （P 〉 0.05）. The distribution of TT genotype and T allele frequencies of the MDR1 gene was significantly different in the refractory epilepsy group compared with the drug-responsive epilepsy and normal control groups （P 〈 0.05）. Comparison of haplotype combinations demonstrated that there were no significant differences in combinations of TT＋CC, -FI-＋CT, TC＋CC, and TC＋CT among the three groups （P 〉 0.05）. CONCLUSION： C270T polymorphism of the BDNF gene was not associated with refractory epilepsy in Chinese Han children, but T-129C polymorphism in the MDR1 gene was associated with refractory epilepsy in Chinese Han children. The TT genotype and T allele frequencies could serve as susceptibility loci for refractory epilepsy. Interactions between C270T in BDNF gene and T-129C in MDR1 gene were not observed in refractory epilepsy in Chinese Han children.

High prevalence of multidrug-resistance in Acinetobacter baumannii and dissemination of carbapenemase-encoding genes bla_(OXA-23-like),bla_(OXA-24-like)and bla_(NDM-1) in Algiers hospitals

Objective:To assess and characterize antibiotic resistance in Acinetobacter baumannii strains recovered from 5 health-care facilities in Algiers.Methods:Antibiotic susceptibility testing was performed by agar diffusion and agar dilution methods,resistance genes were identified by PCR and sequencing,and molecular typing of isolates was carried out by enterobacterial repetitive intergenic consensus-PCR(ERIC-PCR).Results:Among 125 tested isolates,117(93.6% ) were multidrug-resistant.of which 94(75.2% ) were imipenem resistant.The bla_(ADC)and bla_(OXA-51-like) genes were detected in all isolates,in association with ISAba I sequence in 84% and 8% (imipenem resistant) of isolates,respectively.The bla_(OXA-23-like) and bla_(OXA-24-like)carbapenemase genes were delected in 67.02% and 20.21% of imipenem-resistant isolates,respectively.The bla_(OXA-23-like) gene is linked to ISAba1 or ISAba4 elements.The metallo-β-lactamase NDM-1 gene was found in 10(10.6% ) imipenem-resisianl strains from three hospitals,it is linked to ISAba125 clement in nine strains.Extended spectrum β-lactamases production was not detected.Imipenem and cefotaxime resistance phenolypes could not be transferred to Escherichia coli by conjugation.Outer membrane protein CarO gene was not delected in four imipenem-resisianl isolates.The aac(6')-1b.sul1,sul2,tetA and tetB genes were present in 5.31% .36.17% .77.65% .1.06% and 65.92% of strains,respectively.Class 1 integrons were detected in 23.4% strains.KRIC-PCR typing showed a genetic diversity among bla_(OXA-23-like) and bla_(OXA-24-like) positive strains,while clonality was observed among bla_(NDM-1)positives.Conclusions:This study highlighted the high prevalence of imipenem resistance in Acinetobacter baumannii in Algiers hospitals mediated mainly by bla_(OXA-23-like),bla_(OXA-24-like),and bla_(NDM-1) genes.

Roles of sulfonylurea receptor 1 and multidrug resistance protein 1 in modulating insulin secretion in human insulinoma

BACKGROUND:Sulfonylurea receptor 1(SUR1)and multidrug resistance protein 1(MRP1)are two prominent members of multidrug resistance proteins associated with insulin secretion. The aims of this study were to investigate their expression in insulinomas and their sole and synergistic effects in modulating abnormal insulin secretion. METHODS:Fasting glucose,insulin and C-peptide were measured in 11 insulinoma patients and 11 healthy controls. Prolonged oral glucose tolerance tests were performed in 6 insulinoma patients.Insulin content,SUR1 and MRP1 were detected in 11 insulinoma patients by immunohistochemistry. SUR1 and MRP1 were also detected in 6 insulinoma patients by immunofluorescence. RESULTS:Insulinoma patients presented the typical demons-trations of Whipple’s triad.Fasting glucose of each insulinoma patient was lower than 2.8 mmol/L,and simultaneous insulin and C-peptide were increased in insulinoma patients. Prolonged oral glucose tolerance tests showed that insulin secretion in insulinoma patients were also stimulated by high glucose.Immunohistochemistry and immunofluorescence staining showed that SUR1 increased,but MRP1 decreased in insulinoma compared with the adjacent islets. CONCLUSIONS:The hypersecretion of insulin in insulinomas might be,at least partially,due to the enrichment of SUR1. In contrast,MRP1,which is down-regulated in insulinomas, might reflect a negative feedback in insulin secretion.

Differential expression of breast cancer-resistance protein,lung resistance protein,and multidrug resistance protein 1 in retinas of streptozotocin-induced diabetic mice

AIM：To investigate the altering expression profiles of efflux transporters such as breast cancer-resistance protein（BCRP）,lung resistance protein（LRP）,and multidrug resistance protein 1（MDR1） at the inner blood-retinal barrier（BRB） during the development of early diabetic retinopathy（DR） and/or aging in mice.METHODS：Relative m RNA and protein expression profiles of these three efflux transporters in the retina during the development of early DR and/or aging in mice were examined.The differing expression profiles of Zonula occludens 1（ ZO-1） and vascular endothelial growth factor-A（ VEGFA） in the retina as well as the perfusion characterization of fluorescein isothiocyanate（FITC）-dextran and Evans blue were examined to evaluate the integrity of the inner BRB.RESULTS：There were significant alterations in these three efflux transporters＇ expression profiles in the m RNA and protein levels of the retina during the development of diabetes mellitus and/or aging.The development of early DR was confirmed by the expression profiles of ZO-1 and VEGFA in the retina as well as the compromised integrity of the inner BRB.CONCLUSION：The expression profiles of some efflux transporters such as BCRP,LRP,and MDR1 in mice retina during diabetic and/or aging conditions are tested,and the attenuated expression of BCRP,LRP,and MDR1 along with the breakdown of the inner BRB is found,which may be linked to the pathogenesis of early DR.

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

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 polymorphisms of C3435T in the MDRl 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： MDRl 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 allele frequency were 25% and 75% in the intractable epilepsy group, and 30% and 70% in the normal control group, respectively. However, there was no statistical difference between the groups. CONCLUSION： Results demonstrated that seizures, not antiepileptic drugs, induced MDR1 gene expression in intractable epilepsy. Genetic polymorphisms of C3435T in the MDR1 gene did not contribute to the development of multidrug resistance in patients with intractable epilepsy.

Detection and clinical significance of multidrug resistance-1 mRNA in bone marrow cells in children with acute lymphoblastic leukemia by real-time fluorescence quantitative RT-PCR

Objective： Multidrug resistance（MDR） is one of the most important reasons for treatment failure and recurrence of acute leukemia. Its manifestations are different in children with acute lymphoblastic leukemia（ALL） which may be due to different detection methods. This study was to detect the expression of MDR1 mRNA in bone marrow cells of children with ALL by real-time fluorescence- quantitative reverse transcription polymerase-chain reaction（FQ-RT-PCR）, and combine minimal residual desease（MRD） detection by flow cytometry（FCM） and to study their relationship with treatment response and prognosis of ALL. Methods：The MDR1 mRNA levels in bone marrow cells from 67 children with ALL[28 had newly diagnosed disease, 27 had achieved complete remission（CR）, 12 recurrent] and 22 children without leukemia were detected by FQ-RT-PCR. MRD was detected by FCM. The patients were observed for 9-101 months, with a median of 64 months. Results：Standard curves of human MDR1 and GAPDH genes were constructed successfully. MDR1 mRNA was detected in all children with a positive rate of 100%. The mRNA level of MDR1 was similar among the newly diagnosed ALL group, CR group, and control group（P 〉 0.05）, but significantly higher in the recurrence group than that in newly diagnosed disease group and control group（0.50 ± 0.55 vs. 0.09 ± 0.26 and 0.12 ± 0.23, P〈 0.05）. 54 ALL patients were followed up, and it was found that MDR1 mRNA level was significantly higher in ALL patients within 3 years duration than that of ALL patients with 3-6 years and over 6 years duration（0.63 ± 0.56 vs. 0.11 ± 0.12 and 0.04 ± 0.06, P〈 0.01）. For the 28 children with newly diagnosed disease, the MDR1 mRNA level was similar between WBC 〉 50 ~ 109 group and WBC〈50 × 10^9 group（P〉 0.05）. In the 33 CR patients, the MDR1 mRNA level was significantly higher in MRD〉10a group than that in MRD〈10a group（0.39 ± 0.47 vs. 0.03 ± 0.03, P 〈 0.05）. Conclusion：The sensitivity and specificity of FQ-RT-PCR in detecting MDR1 mRNA in bone marrowy cells of children with ALL patients are high. MDR1 mRNA is expressed in children with and without leukemia. MDR1 mRNA is highly expressed in the CR ALL patients with high MRD, recurrence and short duration（within 3 years）. Monitoring MRD and the MDR1 mRNA level might be helpful for individual treatment.

Reversal Effect of BM-cyclin 1 on Multidrug Resistance by Down-regulating MRP2 in BALB/C Nude Mice Bearing C-A120 Cells

Our previous study demonstrated that BM-cyclin 1, a traditional anti-mycoplasma drug, could effectively reverse the multidrug resistance （MDR） of C-A120 cells. The present study aims to explore the reversal effect of BM-cyclin 1 on MDR and its mechanisms in BALB/C nude mice bearing C-A120 cells. Irnmunoblotting analysis and reverse transcription-polymerase chain reaction （RT-PCR） were used to study the change in multidrug resistance-associated protein 2 （MRP2） induced by BM-cyclin 1. We found that the expression levels of MRP2 protein and mRNA in C-A120 cells treated with BM-cyclin 1 were reduced significantly. Chemical colorimetry revealed no significant change in the level of glutathione （GSH）. In the xenografl model, the inhibitory rate of C-A120 cells growth in BM-cyclin 1 plus adriamycin （ADM） group was 52%, which was significantly higher than in control group （P〈0.01）. The immunoblotting and RT-PCR results conclusively demonstrated that BM-cycin 1 could significantly reduce the expression of MRP2 in transplanted tumor. In conclusion, BM-cyclin 1 could effectively reverse the MDR of C-A 120 cells in vivo by suppressing the expression of MRP2.

Inhibition of apoptosis-regulatory protein Siva-1 reverses multidrug resistance in gastric cancer by targeting PCBP1

Introduction:Siva-1,as a pro-apoptotic protein,has been shown to induce extensive apoptosis in a number of different cell lines.In our previous study,we showed that overexpressed Siva-1 decreased the apoptosis of gastric cancer cells.So,we believe that it can also work as an anti-apoptotic protein.The present study aimed to determine the specific role of Siva-1 in anticancer drug resistance in gastric cancer in vivo and in vitro and preliminarily reveal the mechanism.Materials and Methods:A vincristine-resistant MKN-28/VCR gastric cancer cell line with stably downregulated Siva-1 was established.The effect of Siva-1 downregulation on chemotherapeutic drug resistance was assessed by measuring the IC50 and pump rate of doxorubicin.Proliferation,apoptosis of cells,and cell cycle were detected via colony formation assay andflow cytometry,respectively.Additionally,migration and invasion of cells was detected via wound healing and transwell assays.Moreover,we determined in vivo effects of LV-Siva-1-RNAi on tumor size,and apoptotic cells in tumor tissues were detected using TUNEL and hematoxylin and eosin staining.Results:Siva-1 downregulation reduced the pump rate of doxorubicin and enhanced the response to drug treatment.Siva-1 negatively regulated proliferation and promoted apoptosis of cells by potentiality G2-M phase arresting.Inhibition of Siva-1 expression in MKN-28/VCR cells significantly weakened wound healing ability and decreased invasion ability.Poly(C)-binding protein 1(PCBP1)was identified as a Siva-1-interacting protein in yeast two-hybrid screening.Semiquantitative RT-PCR and western blotting revealed that Siva-1 downregulation could inhibit expression of PCBP1,Akt,and NF-κB and eventually decrease the expression of MDR1 and MRP1.Conclusion:The current study demonstrated that the downregulation of Siva-1,which functions as a regulator of MDR1 and MRP1 gene expression in gastric cancer cells by inhibiting PCBP1/Akt/NF-κB signaling pathway expression,enhanced the sensitivity of gastric cancer cells to certain chemotherapies.

Role of Na^+/H^+ exchanger isoform-1 in doxorubicin-induced multidrug-resistance HL-60 cell line

Objective: To explore the roles of intracellular pH value (pHi) and sodium-hydrogen exchanger isoform-1 (NHE-1) in the mechanism of multidrug resistance of leukemia cells. Methods: Multidrug resistant cell line HL-60 induced by doxorubicin(DOX) (called as HL-60/DOX cells) and their parent cell line HL-60 were employed as experiment group and control group. The proliferation and chemosensitivity of the cells were studied by MTT assay, and the expression of multidrug resistance protein (MRP) was detected by immol/Lunocytochemistry. Meanwhile, pHi was measured by spectrofluorometery with a fluorescence dye BCECF-AM. Based on the pHi recovery curve after intracellular acid loading, the activity of NHE-1 was analyzed. The expression of NHE-1 mRNA and MRP mRNA were determined by semi-quantitative RT-PCR. Cell apoptosis was observed with terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL), and apoptotic DNA was extracted and electrophoresed. Results: ① The IC 50 values for DOX, MTZ, VCR and homoharringtonine(HT), in HL-60/DOX cells were significantly higher than those in HL-60 cells (P<0.01). HL-60/DOX cells expressed abundant MRP, but HL-60 cells did not. ② pHi of HL-60/DOX cells were significantly higher than that of HL-60 cells(P<0.001). The expression and activity of NHE-1 in HL-60/DOX cells were significantly stronger than those of HL-60 cells. ③After administration of the specific NHE-1 inhibitor dimethyl amiloride (DMA) at a certain range of concentrations, compared with HL-60 cells, the rate of growth inhibition of HL-60/DOX cells increased significantly (P<0.05), the drug-sensitivity of HL-60/DOX cells was significantly sensitive (P<0.01), the expression of MRP and MRP mRNA decreased significantly (P<0.01), the apoptosis rate increased significantly (P<0.01). Conclusion: NHE-1 is involved in the drug-resistant mechanisms of multidrug-resistant HL-60 cells induced by DOX. The specific NHE-1 inhibitor DMA can partly reverse the multidrug resistance of HL-60 cells induced by DOX.

白介素37下调多药耐药基因-1逆转肺腺癌紫杉醇耐药的研究

目的 本研究旨在探究白介素37(IL-37)在抑制肺腺癌细胞多药耐药性方面的潜在作用,及其对于耐紫杉醇的A549/TAX细胞的影响。方法 通过细胞培养、处理程序、实时荧光定量PCR、Western blot分析和统计学分析等实验方法,系统研究了IL-37对耐紫杉醇A549/TAX细胞的影响。结果 紫杉醇明显抑制了A549和A549/TAX细胞的增殖,其中A549/TAX的耐药指数RI为16.88。100ng/mL的rhIL-37显著抑制了A549/TAX细胞的增殖。在紫杉醇和rhIL-37联合处理组,细胞增殖的抑制率显著高于仅用紫杉醇处理组(P<0.05)。此外,rhIL-37在24小时后显著抑制了A549/TAX细胞的迁移和侵袭。非细胞毒性浓度的rhIL-37也能显著抑制A549/TAX细胞的集落形成。经rhIL-37作用48小时后,A549/TAX细胞中MDR1的表达水平比对照组下降了约66%(P<0.05)。结论 IL-37与紫杉醇联合处理可有效抑制A549/TAX细胞的增殖、迁移和侵袭,同时通过降低MDR1基因的表达水平可能逆转细胞的耐药性,为IL-37在肺腺癌治疗中的潜在应用提供了实验依据。

Plasmid mediated antibiotic resistance of Vibrio cholerae Ol biotype E1 Tor serotype Ogawa associated with an outbreak in Kolkata,India

Objective:To determine the antibiotic resistance of Vibrio choleras(V.cholerae) O1 biotype El Tor serotype Ogawa isolates involved in an outbreak of watery diarrhea in Kolkata,and to explore the role of plasmid in mediating antibiotic resistance.Methods:Antibiotic susceptibility and minimum inhibitory concentration(MIC) values of antibiotics for the isolated V.cholerae 01 Ogawa(n=12) were determined by disk diffusion and agar dilution methods,respectively,using ampicillin(Am),chloramphenicol(C),trimethoprim(Tm),tetracycline(T).erythromycine(Er), nalidixic acid(Nx).ciprofloxacin(Cp),amikacin(Ak) and cefotaxime(Cf).Plasmid curing of multidrug resistant(MDR) V.cholerae 01 Ogawa strains was done following ethidium bromide treatment.Following electrophoresis,the plasmid DNAs,extracted from the isolated MDR V. cholerae O1 Ogawa strains and their cured derivatives,were visualized and documented in ’gel doc’ system.Results:The outbreak causing V.cholerae O1 Ogawa isolates were MDR as determined by disk diffusion susceptibility test,and MIC determination.The isolates showed three different drug resistance patterns:AmTmTErNx(for 6 isolates).TmTErCp(for 5 isolates), and AmTniNx(for one isolate),and showed uniform sensitivity to C,Ak and Cf.The loss of plasmids with the concomitant loss of resistance to Am,Tm,T and Er of the isolates occurred following ethidium bromide treatment.Conclusions:The current findings suggest that the V. cholerae O1 Ogawa associated with the cholera outbreak were MDR,and resistance to Am,Tm,T and Er among the isolates were plasmid mediated.

SIRT1在结直肠癌组织中的表达及其与MDR-1的关系

目的探讨沉默信息调节因子1(SIRT1)在结直肠癌组织中的表达及其与多药耐药相关蛋白1(MDR-1)的关系。方法选择结直肠癌患者162例,取手术切除的癌组织,采用免疫组化Envision法观察SIRT1、MDR-1的阳性表达,分析结直肠癌组织SIRT1阳性表达与患者临床病理参数及MDR-1阳性表达的关系。结果结直肠癌组织中SIRT1、MDR-1阳性表达率分别为66.0%(107/162)和59.3%(96/162)。结直肠癌组织SIRT1阳性表达与患者性别、肿瘤组织分化程度、临床分期及淋巴结转移无关(P均>0.05),与肿瘤长径有关(P<0.05)。结直肠癌组织SIRT1阳性表达与MDR-1阳性表达呈正相关(r=0.506,P<0.01)。结论结直肠癌组织中SIRT1阳性表达较高,其阳性表达与MDR-1阳性表达呈正相关关系。

mdr-1和bcl-2基因在K562/ADM多药耐药细胞中的共表达

为探讨肿瘤细胞多药耐药(MDR)形成的分子机理,本文观察了mdr-1、bcl-2和bax基因及其编码蛋白在人红白血病细胞株K562/ADM中的可能共表达。结果显示,在K562/ADM细胞中,在以mdr-1及P-gp过度表达为 特征的MDR形成时,其bcl-2及产物Bcl-2也过度表达,其中Bcl-2的表达阳性率约为相应敏感株K562的11倍;而Bax在二种细胞中均呈阳性表达,但无显著差异(P>0.05),提示bcl-2基因在mRNA和蛋白水平上的过度表达可能是K562/ADM细胞MDR形成时细胞凋亡耐受的分子基础。

复发转移性乳腺癌mdr-1基因产物P-糖蛋白表达的临床意义

目的 探讨复发转移性乳腺癌mdr 1基因表达产物P 糖蛋白 (P glycoprotein ,P gp)表达及其与含吡喃阿霉素联合方案化疗疗效的关系。方法 应用SABC法检测 4 6例转移性乳腺癌术后组织中P gp表达 ,使用环磷酰胺、吡喃阿霉素和 5 氟尿嘧啶联合方案化疗 ,对比分析P gp表达与疗效的关系。 结果 ① 4 6例患者mdr 1基因表达产物P gp阳性表达率 5 6 .5 % ,肝或肺转移者阳性表达明显高于皮肤或淋巴结转移者 (P =0 .0 4 9)。②可评价疗效的 4 3例患者化疗有效率 5 8.1% ;P gp阴性组疗效 (89.5 % )明显优于P gp阳性组 (30 .0 % ) (P <0 .0 1)。③有肝或肺转移者有效率(4 0 .7% )明显低于皮肤或浅表淋巴结转移者 (87.5 % ) (P <0 .0 5 )。④术后曾接受辅助性CAF或CMF方案化疗者复发转移后化疗疗效 (71.4 %和 37.5 % )无显著性差异 (P =0 .0 5 2 )。结论 mdr 1基因表达产物P

三羟异黄酮对人乳腺癌耐药细胞mdr-1、HER2/neu表达的影响

目的研究三羟异黄酮(Genistein,GEN)对体外培养人乳腺癌MCF-7/ADM耐药细胞中mdr-1、HER2/neu基因及蛋白表达的影响,探讨其逆转多药耐药机制。方法采用MTT法检测GEN作用MCF-7/ADM细胞后的细胞增殖抑制率(IR)和半数抑制浓度(IC50);RT-PCR法检测MCF-7/ADM细胞经不同浓度阿霉素(ADM)、GEN及GEN联合ADM处理后,其mdr-1、HER2/neu mRNA表达的变化;Western blot检测其对c-erbB2蛋白及P-糖蛋白(P-gp)的影响。结果 GEN对MCF-7/ADM细胞生长抑制作用明显,其抑制效应呈时间-剂量依赖性,特别是GEN浓度增加到60μg/mL时,对细胞抑制作用急剧升高(P<0.01)。MCF-7/ADM细胞中有mdr-1、HER2/neu过量表达,经GEN单独及联合ADM作用后,HER2/neu mRNA表达明显下调,c-erbB2蛋白出现一致性的表达下调,但对mdr-1mRNA及P-gp无影响。结论人乳腺癌MCF-7/ADM细胞耐药性与耐药基因及原癌基因的高表达相关,GEN能下调MCF-7/ADM细胞HER-2/neu基因及蛋白表达,可能是其逆转MCF-7/ADM细胞多药耐药性的机制之一,但对由P-gp介导的多药耐药无效。

PIC-BE对K_(562)/ADM多药耐药细胞mdr-1和bcl-2基因表达的影响

本文以多药耐药(MDR)细胞株K_(562)/ADM作为实验模型,研究了β-榄香烯吗素(PIC-BE)对该细胞中mdr-1、bcl-2和bax基因及其编码蛋白(P-gp、Bcl-2和Bax)表达的影响。结果显示,PIC-BE可显著抑制K_(562)/ADM细胞中mdr-1、bcl-2及P-gp和Bcl-2的表达,并在一定的范围内呈现对浓度和时间的依赖性。相同条件下,PIC-BE对该细胞中Bax的表达虽有所促进,但统计学上无显著差异,提示PIC-BE对K_(562)/ADM细胞MDR的逆转作用可能是通过其直接或间接地影响到该细胞mdr-1、bcl-2及P-gp和Bcl-2的表达或功能而实现。

重组腺病毒Ad-EGFP-mdr-1转染大鼠骨髓细胞模型的构建

目的构建转染多药耐药基因-1(multidrug resistance gene-1,mdr-1)的骨髓细胞。方法将重组腺病毒Ad-EGFP-mdr-1转染大鼠骨髓细胞。RT-PCR法和Western blot法检测mdr-1 mRNA及蛋白的表达水平;柔红霉素排出试验检测转染mdr-1基因后的骨髓细胞有无功能表达。结果骨髓细胞病毒转染率为30.14%,存活率为89.25%,转染后骨髓细胞mdr-1的mRNA及蛋白质水平都存在功能性表达,导入的mdr-I表达产物P-gp有药物外排泵功能。结论转染mdr-1的大鼠骨髓细胞模型的成功构建,为进一步研究肿瘤的多药耐药提供实验基础。

赤道几内亚Bioko岛的恶性疟原虫多药抗性基因(pfMDR-1)的研究

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。

Congenital expression of mdr-1 gene in tissues of carcinoma and its relation with patho morphology and prognosis

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