维拉帕米对MDR1基因转染的Swiss－3T3细胞的化疗增敏作用

为进一步了解维拉帕米对抗药性逆转作用的待征，在人ＭＤＲ１基因转染的Ｓｗｉｓｓ－３Ｔ３多药抗药性细胞，观察了维拉帕米逆转幅度与阿霉素抗性水平的关系。各个转染细胞与母细胞相比，阿霉素毒性明显降低。非毒性浓度（３Ｕｍｏｌ·Ｌ－１）的维拉帕米对阿霉素毒性的增强作用，在转染细胞均高于母细胞，但逆转幅度与抗性水平成反比。Ｓｏｕｔｈｅｒｎ杂交显示，转染细胞基因组中有ＭＤＲ１ｃＤＮＡ整合。转染细胞的阿霉素蓄积障碍可被维拉帕米纠正。讨论了药物主动转运的饱和现象在维拉帕米增强效应中的作用，以及Ｐ－糖蛋白与药物相互作用的方式。     

MDR1基因转染的Swiss3T3细胞经秋水仙碱孵育后多药抗药性模式改变

为观察长期药物筛选对多药抗药性模式的影响，用ＭＤＲ１ｃＤＮＡ转染了Ｓｗｉｓｓ３Ｔ３细胞．秋水仙碱选择培养两个月前后，以ＭＴＴ方法测定各转化子对阿霉素，长春新碱，秋水仙碱的抗药性，以确定其多药抗药性模式．还测定了维拉帕米对各转化子的增敏效应．在非选择培养液中生长的转化子观察到基本一致的抗药性模式，即对长春新碱高度抗性，对秋水仙碱中度抗性，对阿霉素低度抗性．而在选择培养液中生长两个月后，各转化子的抗药性模式变得参差不齐．结果说明，ＭＤＲ１基因表达可造成一致的抗药性模式，长期秋水仙碱孵育可改变抗药性模式的均一性．     

MDR1基因转染的Swiss 3T3细胞经秋水仙碱孵育后多药抗药性模式改变

为观察长期药物筛选对多药抗药性模式的影响，用MDR1 cDNA转染了Swiss 3T3细胞. 秋水仙碱选择培养两个月前后，以MTT方法测定各转化子对阿霉素，长春新碱，秋水仙碱的抗药性，以确定其多药抗药性模式. 还测定了维拉帕米对各转化子的增敏效应. 在非选择培养液中生长的转化子观察到基本一致的抗药性模式，即对长春新碱高度抗性，对秋水仙碱中度抗性，对阿霉素低度抗性. 而在选择培养液中生长两个月后，各转化子的抗药性模式变得参差不齐. 结果说明，MDR1基因表达可造成一致的抗药性模式，长期秋水仙碱孵育可改变抗药性模式的均一性.     

热化疗对K562细胞体外增敏作用的实验研究

目的观察热疗联合阿霉素对人慢性白血病细胞株K562细胞内的药物浓度变化及凋亡的影响。方法MTT法确定阿霉素的工作浓度,以该浓度进行化疗或与热疗的联合,选择温度40、41、42℃,体外作用于K562细胞。作用前及作用48h采用台盼蓝拒染法检测肿瘤细胞的存活率;MTT法检测肿瘤细胞增殖的抑制作用;流式细胞仪检测肿瘤细胞的凋亡及细胞内药物浓度的变化。观察热疗联合阿霉素的抗肿瘤效果。结果作用48h IC50的药物浓度作为实验的工作浓度。热化疗组对K562细胞有明显的抑制作用(P<0.01),随着温度的增高而增强;热化疗组细胞内的药物浓度明显增加(P<0.01)。结论热疗联合阿霉素能增加K562细胞内的药物浓度,提高肿瘤细胞的凋亡率。     

阿霉素细胞水平药物动力学在维拉帕米对Swiss—3T3细胞的化学增…

确定维拉帕米对药物敏感细胞深化增敏效应中，阿霉素细胞药物动力学是否起作用。     

阿霉素细胞水平药物动力学在维拉帕米对Swis－3T3细胞的化学增敏效应中不起作用

阿霉素细胞水平药物动力学在维拉帕米对Ｓｗｉｓ３Ｔ３细胞的化学增敏效应中不起作用王楠，汤仲明，章扬培，丁清明（北京放射医学研究所，北京１００８５０，中国）关键词阿霉素；维拉帕米；抗药性；药物动力学；成纤维细胞；培养的肿瘤细胞目的：确定维拉帕米（Ｖｅｒ...     

甲基莲心碱对MCF-7细胞体外化疗增敏作用

目的探讨甲基莲心碱(Neferine,Nef)的体外化疗增敏作用.方法以人乳腺癌细胞MCF-7为研究对象,MTT法测定药物的细胞生长抑制率,流式细胞仪(Flowcytometry,FCM)检测细胞凋亡.结果Nef(5umol*L-1、10umol*L-1)分别与阿霉素(ADM)、5-氟尿嘧啶(5-FU)、顺铂(CDDP)合用,可增加它们对MCF-7细胞的生长抑制率,q＞1.Nef(10umol*L-1可增强10umol*L-1ADM诱导MCF-7细胞凋亡的作用.结论Nef具有化疗增敏作用.     

维拉帕米对胶质瘤细胞卡氮芥化疗敏感性的作用

目的探讨维拉帕米对不同胶质瘤细胞（U251、SHG-44）卡氮芥（BCNU）化疗敏感性的作用及其机制。方法通过免疫组化测定BCNU化疗前后肿瘤细胞中的耐药基因的表达;用MTT实验评估BCNU及维拉帕米作用前后化疗的细胞生长情况。结果 U251细胞中BCNU化疗前耐药基因LRP表达阳性,MRP阴性,P-gp阴性;化疗后LRP仍为阳性,MRP转变为阳性,P-gp为弱阳性,加入维拉帕米后细胞生长情况无明显差异（P〉0.05）;SHG-44细胞中,BCNU化疗前,LRP为阳性,P-gp和MRP1为阴性,化疗后上述基因表达无差异,加入维拉帕米后细胞生长受到明显抑制（P〈0.05）。结论维拉帕米对细胞化疗前后表达不同耐药基因的化疗敏感性具有不同的作用。     

维拉帕米对肿瘤细胞多药抗药性的逆转作用

维拉帕米对肿瘤细胞多药抗药性的逆转作用应明（南京八一医院骨科，２１０００２）中国图书分类号Ｒ９７９．１恶性肿瘤的抗药性是化疗无效的重要原因。肿瘤细胞的抗药性就其来源可分为内在性抗药性（ｉｎｔｒｉｎｉｃｄｒｕｇｒｅｓｉｓｔａｎｃｅ）和获得性抗药性（ａｃ...     

褪黑素的抗肿瘤作用机制和化疗增敏作用研究现状

褪黑素(MLT)是由松果腺合成与分泌的神经内分泌活性物质,其以色氨酸为原料,经过羟化、脱羧及N-乙酰转移酶等的催化后而最终形成.MLT可迅速进入血液循环,分布到全身各部位发挥生理活性.现已证实,MLT除了可保证正常生物节律、调节内分泌腺的功能、抗应激和延缓衰老外,与肿瘤的发生、发展及治疗亦有着密切的关系[1].     

Association of MDR1 genotypes with susceptibility to colorectal cancer in older non-smokers

Objective The multidrug resistance gene 1 (MDR1) seems to play a role in the carcinogenesis of colorectal tumors. The importance of MDR1 SNPs 2677G > T/A in exon 21 and 3435C > T in exon 26 for cancer susceptibility, however, has not yet been clearly defined. Methods Two hundred and eighty-five colorectal cancer patients and 275 controls from five hospitals in the European part of Russia were genotyped for the polymorphisms −129T > C (rs3213619) in exon 1b, 2677G > T/A (rs2032582), and 3435C > T (rs1045642) in this population-based case-control study. Genotype-phenotype analysis was performed with simultaneous consideration of lifestyle risk factors. Results Our analysis confirmed the preponderate impact of smoking on colorectal cancer development. The risk of heavy smokers (≥60 pack years) to develop colorectal cancer by far exceeded that of lifelong non-smokers (OR = 3.9, 95% CI: 1.4 to 10.6). Smoking is a more potent risk factor than is the genetic influence of MDR1 in our study. However, a smoking and age-stratified analysis, revealed a statistically significant association between MDR1 genotypes and colorectal cancer in life-long non-smokers with an age ≥63 years (the median age in our sample). The association was stronger for rectal cancer than for colon cancer. Patients who carried the genotypes (−129TT; 2677GG; 3435CC) or (−129TT; 2677TT; 3435TT) developed more frequently colorectal cancer than others (OR = 3.9; 95% CI: 2.0 to 7.7). Conclusions Our results show that the interaction of genetic and lifestyle risk factors should be taken into account to elucidate the genetic influence of MDR1 variability on cancer susceptibility.     

人参三醇皂甙促进人白细胞介素3的基因表达

应用mRNA麦胚无细胞体系动态地观察了人参三醇皂甙(PTGS)对人淋巴结细胞白细胞介素3(IL-3)基因表达的促进效应。结果表明,PTGS可以明显促进植物血凝素(PHA)活化人淋巴细胞分泌IL-3,最大促进效应达30%,高峰时相为刺激后72h。PTGS+PHA共刺激后细胞浆IL-3mRNA转译IL-3的量明显高于单纯PHA组,最大促进效应为40%,高峰时相为刺激后60h。从而首次证明PTGS促进了IL-3基因表达,使IL-3基因表达效能增强,最终促进了IL-3合成。     

Pesticides and their binary combinations as P-glycoprotein inhibitors in NIH 3T3/MDR1 cells

The purpose of the present study was to assess do selected pesticides as well as their binary combinations act as inhibitors of P-glycoprotein (P-gp) activity of NIH 3T3 mouse fibroblasts stably transfected with human MDR1 gene (NIH 3T3/MDR1). As a result of P-gp inhibition, the increase of intracellular accumulation of a model P-gp substrate fluorescent calcein acetoxymethyl ester was measured. Pesticide and verapamil individual dose–response data were scaled and expressed as percent of maximum effect. Results showed that out of 14 pure pesticides tested, endosulfan, phosalone and propiconazole were nearly as potent as model inhibitor verapamil (EC₅₀ = 1.5 μM), while diazinon showed a lower potency of inhibiting P-gp transport activity (EC₅₀ = 58.4 μM). Concentrations of pesticides that produced the same inhibiting effect (isoboles) were combined binary. Results calculated using the isobole method revealed that diazinon caused synergistic effect in inhibiting P-gp transport activity in all combinations.     

人参皂苷Rb1对慢性吗啡作用的SK-N-SH细胞的影响

目的：探讨人参皂苷Rb1对慢性吗啡作用的SK-N-SH细胞钙调蛋白激酶Ⅱβ（CaMKⅡβ）mRNA、蛋白及cAMP反应原件结合蛋白磷酸化（pCREB）表达的影响。方法：用终浓度为100 μmol·L-1的吗啡、不同浓度人参皂苷Rb1及终浓度为10 μmol·L-1的纳络酮,单独或共同作用于SK-N-SH细胞,采用RT-PCR、Western-blot及免疫组织化法分别研究人参皂苷Rbl对慢性吗啡及纳洛酮作用于SK-N-SH细胞时,CaMKⅡβmRNA、蛋白表达及核转录因子pCREB表达的影响。结果：与对照组相比,终浓度为100 μmol·L-1的吗啡,作用48 h可以显著增加CaMKⅡβmRNA、CaMKⅡβ蛋白及pCREB表达;吗啡作用完毕,再加入终浓度为10 μmol·L-1的纳络酮,作用30 min,CaMKⅡβmRNA、CaMKⅡβ蛋白及pCREB表达进一步增加;8 μmol·L-1、16 μmol·L-1、32 μmol·L-1的Rb1可以显著抑制上述指标。结论：人参皂苷Rb1可能通过调控CaMKⅡβmRNA、CaMKⅡβ蛋白表达及核转录因子CREB的磷酸化,对慢性吗啡作用的SK-N-SH细胞产生影响。     

人甲状旁腺素(1-34)对新生大鼠成骨细胞碱性磷酸酶活性影响

目的：研究外源性hPTH(1-34)对原代培养成骨细胞ALP活性影响。方法：新生大鼠头盖骨中取成骨细胞,改良Gomori氏钙钴法染色鉴定,磷酸苯二钠法测定ALP活性,RT-PCR检测ALP mRNA表达。结果：10^-8 mol.L^-1 hPTH(1-34)以48 h为一循环,在每一循环的前12 h作用于细胞时,可使成骨细胞ALP活性较对照组增加最明显,hPTH(1-34) 48 h作用组,与对照相比细胞ALP活性无显著差异。hPTH(1-34) 12 h作用组,成骨细胞ALP mRNA表达最高。结论：hPTH(1-34)刺激成骨细胞内ALP活性升高与给药方式及药物浓度有关,间歇性给药成骨细胞内ALP活性升高。     

MDR1基因多态性与美罗培南血药浓度及临床疗效的相关性研究

目的 考察多药耐药基因1(MDR1)的基因多态性在中国南方人群中的分布,明确其对美罗培南稳态血药浓度的影响及临床疗效的相关性。方法 纳入101例美罗培南治疗的患者,用高效液相色谱法测定美罗培南稳态血药浓度,聚合酶链式反应(PCR)和DNA测序技术检测基因分型。比较MDR1 C3435T(rs1045642)不同基因型对美罗培南稳态血药浓度及临床疗效的影响。结果 101例患者中,浓度达到5~20μg/mL的比例为34.9%,5~10μg/mL与10~20μg/mL浓度范围美罗培南的临床有效率(83.3%, 91.7%)显著高于5μg/mL以下浓度范围(44%)(P<0.05),同时5~10μg/mL与10~20μg/mL浓度范围美罗培南的临床有效率无显著差异(P＞0.05)。MDR1 C3435T突变型和野生型患者的美罗培南浓度、浓度/剂量比及临床疗效无显著差异(P＞0.05)。结论 MDR1 C3435T基因突变可能与患者美罗培南稳态血药浓度及临床疗效无关。     

MDR1 C1236T和G2677T/A基因多态性对肾移植受者他克莫司血药浓度影响的Meta分析

目的：系统评价多药耐药基因1（MDR1）C1236T和G2677T/A多态性对肾移植受者他克莫司（FK506）血药浓度的影响,为临床个体化应用FK506提供循证参考。方法：计算机检索PubMed、Embase、Cochrane Library、CNKI数据库和万方数据库,检索时限均为建库起至2020年11月。收集MDR1（C1236T,G2677T/A）基因多态性对肾移植受者FK506血药浓度影响的研究,用Rev Man 5.3软件进行Meta分析。结果：共纳入12篇（中文5篇,英文7篇）相关研究,共计1 083例患者。其中,涉及C1236T的研究为9项,涉及G2677T/A的研究为10项。Meta分析结果显示：MDR1 C1236T基因型方面：MDR1 C1236T基因中CC型患者与CT型比较,FK506血药浓度/校正剂量值差异无统计学意义[SMD＝2.18,95% CI （-2.84,7.19）,P=0.40];MDR1 C1236T基因中CC型患者与TT型比较,FK506血药浓度/校正剂量值差异无统计学意义[SMD＝6.02,95% CI （-4.12,16.17）,P=0.24];MDR1 C1236T基因中CT型患者与TT型比较,FK506血药浓度/校正剂量值差异无统计学意义[SMD＝-0.13,95% CI （-7.71,7.44）,P=0.97]。MDR1 G2677T/A基因型方面：MDR1 G2677T/A基因中GG型患者FK506血药浓度/校正剂量值显著低于GA+GT型[SMD＝-6.91,95% CI （-12.39,-1.42）,P=0.01],亚组分析结果显示：术后12月[SMD＝-18.62,95% CI （-23.41,-13.82）,P<0.000 01],MDR1 G2677T/A基因中GG型患者FK506血药浓度/校正剂量值显著低于GA+GT型;MDR1 G2677T/A基因中GG型患者FK506血药浓度/校正剂量值显著低于TT+TA+AA[SMD＝-9.15,95% CI （-16.68,-1.61）,P=0.02],亚组分析结果显示：术后12月[SMD＝-19.81,95% CI （-39.29,-0.32）,P=0.05],MDR1 G2677T/A基因中GG型患者FK506血药浓度/校正剂量值显著低于TT+TA+AA;MDR1 G2677T/A基因中GA+GT型患者FK506血药浓度/校正剂量值与TT+TA+AA型比较,差异无统计学意义[SMD＝-4.56,95% CI （-9.32,0.19）,P=0.06]。结论：MDR1G2677T/A基因多态性与FK506血药浓度/校正剂量值有一定的相关性,且GA+GT或者TT+TA+AA型>GG型,而MDR1 C1236T基因多态性与肾移植受者FK506血药浓度/校正剂量值无相关性。     

Human MDR1 polymorphism: G2677T/A and C3435T have no effect on MDR1 transport activities

The two most frequently observed single nucleotide polymorphisms (SNPs) of the human multidrug resistance 1 (MDR1) gene are 2677G/T/A (893Ala/Ser/Thr) and 3435C/T (no amino acid substitution). In this study, six forms of MDR1 cDNAs with the SNPs were expressed in LLC-PK1 cells and their transport activities were determined. Nearly identical amounts of the recombinant MDR1 proteins were expressed in the established cell lines using the Flp recombinase, which integrates a gene of interest at a specific genomic location. Four structurally diverse compounds: verapamil, digoxin, vinblastine and cyclosporin A, were examined for transcellular transport activities and intracellular accumulation. No significant differences were observed between cells expressing five polymorphic types of the MDR1 cDNAs (2677G/3435T, 2677A/3435C, 2677A/3435T, 2677T/3435C, 2677T/3435T) and cells expressing the wild-type (2677G/3435C). These results suggested that the two frequently observed MDR1 SNPs had no effect on the transport activities of MDR1 proteins expressed in LLC-PK1 cells in vitro, and other genetic or environmental factors might control the expression of MDR1 and the in vivo activity of MDR1.