逆转胶囊含药血清对人乳腺癌耐药株MCF-7/ADR细胞P-gp蛋白表达的影响

目的探讨逆转胶囊在乳腺癌多药耐药中的应用。方法应用流式细胞技术,测定逆转胶囊含药血清对人乳腺癌耐药株MCF-7/ADR细胞P-gp蛋白表达的影响。结果阿霉素单用对P-gp表达无明显影响,其余各处理组与对照组(正常鼠血清组)比较P-gp的荧光表达率均有所下降;逆转胶囊含药血清能显著抑制MCF-7/ADR细胞P-gp表达;阿霉素与10%含药鼠血清合用,对人乳腺癌耐药MCF-7/ADR细胞P-gp蛋白表达的抑制效果良好,P-gp荧光表达率的下降幅度大,与异博定+阿霉素+10%正常鼠血清组无明显差异。结论逆转胶囊含药血清能显著抑制MCF-7/ADR细胞P-gp表达;并有耐药逆转作用。

5-Fu抗结肠癌作用与细胞凋亡及P-gp蛋白表达的关系

目的探讨5-氟尿嘧啶(5-Fu)抗结肠癌作用中,细胞凋亡与P-gp(P-glycoprotein)蛋白表达的关系。方法应用琼脂培养MTT法,测定人结肠癌对抗代谢药的药物敏感性,同时观察5-Fu对结肠癌病人手术前化疗疗效;用S-P免疫组化和图像定量分析技术,测定34例人结肠癌组织中P-gp蛋白表达量;采用末端标记法(TUNEL),检测结肠癌细胞的凋亡指数。结果(1)P-gp蛋白表达量与5-Fu抗药指数呈正相关(r=0.675,P<0.05)。(2)凋亡率与5-Fu抗药指数呈负相关(r=-0.53,P<0.05)。(3)以5-Fu抗药指数1.0为界,>1为耐药组,<1为敏感组,两组间P-gp蛋白表达量、凋亡指数差异均有显著性(P<0.05)。结论5-Fu通过诱导细胞凋亡产生抗结肠癌作用,而P-gp蛋白高表达阻碍5-Fu诱导的凋亡。

Sirt1、P53及P-gp在胃癌中的表达及其临床意义

目的探讨沉默信息调节因子1(Sirt1)、P53及P-糖蛋白(P-gp)在胃癌组织中的表达、临床病理意义及对生存预后的影响。方法采用免疫组化方法检测胃癌组织及正常组织石蜡切片中的Sirt1、P53及P-gp的表达,KaplanMeier生存曲线分析68例患者生存时间与上述指标的表达水平的关系。结果肿瘤组织中Sirt1、P53及P-gp的表达较正常组织表达增高(P<0.001)。Sirt1的高表达与胃癌浸润深度、淋巴结转移及TNM分期有关,且浸润深度越深、有淋巴结转移及临床分期升高时表达随之升高(P<0.05)。Sirt1阳性表达和P53、P-gp之间存在一定的相关性(P<0.001)。Sirt1阳性表达的患者生存时间较Sirt1阴性表达者低(P<0.001)。结论 Sirt1、P53及P-gp在胃癌组织中呈现高表达,且与胃癌的病理学特征有相关性;联合检测Sirt1、P53及P-gp表达可作为一组判断患者生存时间及预后的指标。

P-gp170、GST-π、TOPOⅡ在外周T细胞淋巴瘤中的表达及意义

目的:探讨多药耐药(MDR)相关的P糖蛋白(P-gp170)、谷胱甘肽-S-转移酶(GST-π)、拓扑异构酶(TOPOⅡ)在不同亚型外周T细胞淋巴瘤(PTCL)的表达情况以及和化疗反应性、预后的关系。方法:应用免疫组化方法检测64例经病理确诊的PTCL患者病理组织P-gp170、GST-π、TOPOⅡ的表达情况,并分析它们之间的相关性以及与病理亚型、化疗效果、预后的关系。结果:64例患者中PTCLP-gp170、GST-π、TO-POⅡ表达阳性率分别为57.8%(37/64)、51.6%(33/64)和53.1%(34/64)。三者的表达无显著的相关性(P>0.05)。P-gp170在PTCL-U和ALK+ALCL两组中的表达具有显著性差异(P=0.0182)。P-gp170表达强阳性和首程化疗后完全缓解(CR)、部分缓解(RR),均呈显著负相关(P=0.000)。本文综合定义的MDR高危组(≥2分)和RR具有显著负相关(P=0.002)。P-gp170表达强阳性和MDR高危组和预后相关(P=0.000;P=0.0145)。PTCL的病理亚型、对化疗的反应性(包括CR和RR)为外周T细胞淋巴瘤的独立预后因素。P-gp170糖蛋白、GST-π、TOPOⅡ尚不能作为独立预后因素。结论:P-gp170糖蛋白、GST-π、TOPOⅡ的表达在PTCL的不同亚型中有一定的差异,在一定程度上和PTCL的耐药性以及不良预后有关。

低频重复经颅磁刺激对难治性癫痫大鼠模型脑内P—gP表达的影响

目的：观察低频重复经颅磁刺激（rTMS）对难治性癫痫大鼠模型脑内P-糖蛋白（P—gp）表达的影响。方法：24只大鼠海仁酸注射以建立难治性癫痫模型，随机分为4个造模组：单纯rTMS组、假性rTMS组、丙戊酸钠组和丙戊酸钠＋rTMS联合治疗组，每组6只；另有6只不造模作对照组，只注射等容量生理盐水以作对照。用免疫组织化学方法观察和比较各组动物脑内P—gP的表达。结果：单纯rTMS组大鼠脑内梨状皮层和丘脑区P—gP的表达与假性rTMS组相比明显下降，差异有统计学意义（P=0.003，P=0.005）；丙戊酸钠组大鼠脑内P—gP表达在海马CA3区、梨状皮层和丘脑区明显升高，与联合治疗组比较差异有统计学意义（P=0．008，P=0．003，P=0．001）。结论：低频rTMS可以降低难治性癫痫大鼠脑内P—gP的高表达。

Study on the relationship between P-glycoprotein(P-gp) and C-erbB-2 expression in gastric carcinoma

Objective： To understand the relationship between C-erbB-2 and multidrug resistance （MDR） as well as its clinical significance. Methods： P-gp level was detected by flow cytometry and simultaneously to examine the C-erbB-2 expression level by immunohistochemistry assay in the operating samples. Their relationship was analyzed from 59 cases with gastric carcinoma. Results： The P-gp positive expression was 38/59 （64.4%） cases with gastric carcinoma. The C-erbB-2 positive expression was 21/59 （35.6%） cases with gastric carcinoma. From the analysis of the P-gp and C-erbB-2 relationship, which was involving, range in the gastric carcinoma, that involving two or three sites were more than the site one, in the cases with C-erbB-2 negative. Compared this two groups, there was a significant difference （P = 0.026）. When the C-erbB-2 was positive, the P-gp expression had a significant difference （P = 0.04） in comparing the Ⅲ-Ⅳ stage （lymph node metastasis） with Ⅰ-Ⅱ stage （without lymph node metastasis）. The tumor＇s size, differentiation degree, ages and sex were not related to the C-erbB- 2 and P-gp expression. Conclusion： High level of P-gp expression was related to the C-erbB-2 positive expression in clinical Ⅲ-Ⅳ stage patient with gastric carcinoma （lymph node metastasis）. It suggested that the double positive patient might be a poor prognosis. However, when the C-erbB-2 was negative expression, the clinical staging （with lymph node metastasis） was not related to the P-gp expression in gastric carcinoma patients.

The expression and significance of the multidrug resistance-related proteins P-gp, MRP and LRP in human non-small cell lung cancer tissues

Objective: To explore the expression and significance of the multidrug resistance-related proteins P-glycopro-tein (P-gp), multidrug resistance-related protein (MRP), lung resistance protein (LRP) in human non-small cell lung cancer (NSCLC) tissues and paratumor tissues. Methods: Immunohistochemistry (IHC) was used to examine the expression level of proteins P-gp, MRP and LRP in 43 samples of NSCLC and 15 samples of paratumor tissues. Results: The expression rates of P-gp, MRP and LRP in 43 tumor tissues were 74.42% (32/43), 67.44% (29/43) and 88.37% (38/43), respectively, while in 15 paratumor tissues were 13.33% (2/15), 20.00% (3/15) and 6.67% (1/15), respectively. There was significant difference in the expression of proteins (P-gp, MRP and LRP) between lung cancer tissues and paratumor tissues (P < 0.05). The expres-sion of proteins P-gp, LRP in lung adenocarcinoma were higher than that in other pathological carcinomas (P < 0.05). The expression of protein MRP was not related to pathological type, clinical stage and classification of histodifferentiation (P > 0.05). Conclusion: Multidrug resistance is more common in NSCLC. The proteins of P-gp, MRP and LRP participated in the formation of multidrug resistance in lung cancer. Detection of multidrug resistance-related proteins in lung cancer tissues may be useful to choice drugs.

Establishment and characterization of an oxaliplatin-resistant hepatic cancer cell line

Objective The aim of the current study was to establish an oxaliplatin-resistant hepatoma cell line(HepG2/OXA) and investigate the potential mechanisms of its drug resistance.Methods The hepatoma cell subline, HepG2/OXA, resistant to oxaliplatin(OXA), was established from a parent cell line HepG2, by stepwise exposure to gradually increasing concentrations of OXA over a half-year period. Chemosenstivity of the cytotoxic drugs, OXA, cisplatin(CDDP), adriamycin(ADM), and 5-fuorouracil(5-FU), was determined in HepG2 and HepG2/OXA cells, by the Cell counting kit-8(CCK8) assay. Cell cycle distribution of HepG2 and HepG2/OXA cells was analyzed by Flow cytometry(FCM). The expression levels of several drug resistance-related proteins, such as P-glycoprotein(P-gp), multidrug resistant protein 1(MRP1), and excision repair-cross complementing 1(ERCC1) protein in the two cell lines were tested by the western blot assay.Results The IC50 of OXA in HepG2/OXA and HepG2 were 136.84 μmol/L and 23.86 μmol/L, respectively. The resistance index(RI) was 5.34. HepG2 was also demonstrated to be cross-resistant to other antitumor agents, such as 5-FU, ADM, and CDDP. The percentage of HepG2/OXA cells in the S phase was significantly decreased compared to HepG2 cells(25.58% ± 2.36% vs 14.37% ± 2.54%, P < 0.05), while the percentage of cells in the G0/G1 and G2/M phases showed no statistical difference(respectively 55.29% ± 4.98% vs 56.73% ± 4.56%, P > 0.05, and 24.63% ± 4.81% vs 28.26% ± 3.82%, P > 0.05). The ERCC1 was found to be over expressed in HepG2/OXA cells, while there was no difference in the expressions of P-gp and MRP1 between the multiple drug resistance(MDR) phenotype cell line and its parental cell line.Conclusion HepG2/OXA showed an MDR ability; the over expression of ERCC1 might be associated with the platinum resistance of the cells, but P-gp and MRP1 are not.

B超弹性成像监测下应用吉西他滨耐药乳腺癌细胞4T1构建裸鼠乳腺癌肝转移模型

目的构建吉西他滨耐药乳腺癌细胞4T1耐药株并建立裸鼠乳腺癌肝转移模型。方法采用低浓度加量持续诱导法,诱导吉西他滨耐药乳腺癌细胞4T1耐药株,命名为4T1/Gem;CCK-8法测定4T1与4T1/Gem细胞的增殖抑制率,计算耐药指数;Western blot法检测细胞P-gp蛋白表达;B超引导下注射4T1/Gem细胞悬液诱导裸鼠肝脏成瘤;HE染色观察肿瘤组织病理情况,免疫组化法检测瘤组织ER、PR、HER2、Ki-67和P-gp蛋白的表达。结果经过14个月的诱导成功建立4T1/Gem细胞株,可在含40μg/m L的Gem培养液中稳定生长。4T1/Gem细胞耐药指数为4T1细胞的788.547倍。与亲代相比,4T1/Gem处于G1期和G2期的细胞增加,S期细胞减少;上调P-gp蛋白的表达。4T1/Gem细胞成功建立裸鼠乳腺癌肝转移模型,瘤组织中ER、PR、HER2蛋白阴性表达,Ki-67阳性10%和P-gp蛋白阳性表达。结论成功构建吉西他滨耐药乳腺癌细胞4T1耐药株并建立裸鼠乳腺癌肝转移模型,为开发治疗乳腺癌肝转移化疗耐药的药物提供实验基础。

两种siRNA转染方法对T24/ADM多药耐药性的影响

目的:评价2种转染小干扰RNA(siRNA,small interfering RNA)方法对膀胱癌多药耐药性(MDR)的影响。方法:设计MDR基因的siRNA,用脂质体和电转的方法转染膀胱癌T24/ADM细胞,用RT-PCR分析mRNA的表达,流式细胞仪检测细胞内糖蛋白(P-gp)的表达和阿霉素积累量。结果:siRNA能明显地逆转T24/ADM细胞的多药耐药。电转染的方法抑制基因的效果优于脂质体转染的方法,P-gp表达下调,细胞内阿霉素积累量显著增加(P<0.05)。结论:2种转染方法均能够逆转膀胱癌的多药耐药性,电转染的方法优于化学转染方法。

外排转运体和代谢酶与黄酮的相互作用及其对黄酮肠吸收影响的研究进展

黄酮类化合物大量存在于植物界中,具有广泛的药理作用,可预防及治疗癌症、心脑血管疾病、骨质疏松等。口服给药后,大量黄酮类化合物存在生物利用度低的现象。国内外诸多学者对其吸收代谢机制进行了研究。研究表明,肠上皮细胞的ATP-依赖性外排转运体如P-糖蛋白(P-gp)、多药耐药相关蛋白-2(MRP2)和乳腺癌耐药蛋白(BCRP)和细胞内的Ⅱ相代谢酶(UGT等)是影响黄酮肠吸收的主要因素。综述近年来外排转运体和代谢酶对黄酮类化合物肠吸收影响的研究概况,包括ATP-依赖性外排转运体与代谢酶的协同作用,黄酮类化合物对二者功能的调节作用等,以期为提高黄酮的生物利用度和临床合理利用提供理论依据。

ABCB1基因多态性与难治性癫痫

近年来,难治性癫痫的病因与多药耐药基因以及多药耐药基因与抗癫痫治疗的因果关系越来越受到关注。P糖蛋白(P-glycopretein,P-gp)是由ATP结合盒B亚家族成员1转运蛋白基因(ATP-binding cassette subfamily B member 1 transporter gene,ABCB1)编码的产物。它不仅可以限制抗癫痫药物(antiepileptic drug,AED)的消化道吸收,而且可以在细胞和亚细胞水平调控药物在中枢神经系统的运输过程。除了生理和环境因素的影响,P-gp的功能和表达的变化可能主要取决于ABCB1基因的多态性,这是目前研究得最广泛、最深入的多药耐药机制。本文就目前ABCB1基因多态性与难治性癫痫的相关性研究进展作一综述。