卵巢癌中蛋白激酶C的表达及其临床意义

目的　探讨上皮性卵巢癌组织蛋白激酶C (proteinkinaseC ,PKC)的表达和化疗耐药的关系 ,以及与P -糖蛋白 (P -gp)的相关性。方法　用免疫组化S -P法检测 35例卵巢上皮性肿瘤组织、 2 0例卵巢良性肿瘤组织和 2 0例正常卵巢组织中PKC和P -gp的表达 ,并进行相关临床因素分析。结果　①PKC、P -gp在卵巢恶性肿瘤中的表达明显高于在良性及正常组织中的表达 ;并且PKC和P -gp的表达有相关性 (P <0 0 5 ) ;②卵巢癌PKC的表达与临床病理因素无直接关系 ;③恶性肿瘤中 ,初治和复发的PKC表达阳性率分别为 34 8%和 75 % ;④化疗对PKC表达阳性和阴性卵巢癌患者的有效率分别为 2 3 5 %、 6 6 7% (P <0 0 5 ) ;⑤PKC表达阴性患者的预后优于阳性者 (P =0 0 39)。结论　PKC表达与卵巢癌组织化疗耐药明显相关 ,可能在P -gp介导的卵巢癌多药耐药中起重要作用。     

卵巢癌中PKC和P-gp 的表达及其临床意义

 目的 探讨卵巢癌组织蛋白激酶C(PKC)和P-糖蛋白(P-gp)表达及其临床意义。方法 用免疫组化S-P法检测35例卵巢癌、20例卵巢良性肿瘤和20例正常卵巢组织中PKC和P-gp的表达，并进行相关临床因素分析。结果 (1)PKC、P-gp在卵巢恶性肿瘤中的表达明显高于在良性及正常组织中的表达；初治和复发病例PKC阳性表达有显著差异(P<0．05)。(2)卵巢癌PKC的表达与临床病理因素无直接关系。(3)卵巢癌中PKC和P-gp的表达有显著相关性(P<0．05)。(4)化疗对PKC表达阳性和阴性卵巢癌患者的有效率分别为23．5％、66．7％(P<0．05)。(5)PKC表达阴性患者的预后优于阳性者(P=0．039)。结论 PKC表达与P—gp的表达明显相关，可能在卵巢癌多药耐药中起重要作用。     

Nobiletin and its derivatives overcome multidrug resistance (MDR) in cancer: total synthesis and discovery of potent MDR reversal agents

Our recent studies demonstrated that the natural product nobiletin (NOB) served as a promising multidrug resistance (MDR) reversal agent and improved the effectiveness of cancer chemotherapy in vitro. However, low aqueous solubility and difficulty in total synthesis limited its application as a therapeutic agent. To tackle these challenges, NOB was synthesized in a high yield by a concise route of six steps and fourteen derivatives were synthesized with remarkable solubility and efficacy. All the compounds showed improved sensitivity to paclitaxel (PTX) in P-glycoprotein (P-gp) overexpressing MDR cancer cells. Among them, compound 29d exhibited water solubility 280-fold higher than NOB. A drug-resistance A549/T xenograft model showed that 29d, at a dose of 50 mg/kg co-administered with PTX (15 mg/kg), inhibited tumor growth more effective than NOB and remarkably increased PTX concentration in the tumors via P-gp inhibition. Moreover, Western blot experiments revealed that 29d inhibited expression of NRF2, phosphorylated ERK and AKT in MDR cancer cells, thus implying 29d of multiple mechanisms to reverse MDR in lung cancer.     

L-1416, a novel MDR reversing agent with possible reduced calcium antagonism

BackgroundMultidrug efflux transporter P-glycoprotein (P-gp) is highly expressed on membrane of tumor cells and supposed to be implicated in the resistance to tumor chemotherapy. However, currently none of P-gp inhibitors has been approved by Food and Drug Administration not only due to toxicity but also lack of efficacy in clinical trials.MethodsTo solve the problem, our lab synthesized a novel compound named 1416 [1-(2,6-dimethylphenoxy)-3,4-dimethoxyphenylethylamino) propane hydrochloride] with the hope of high P-gp inhibition and low side effects. Caco-2 cell monolayer and tumor bearing mice were used to evaluate the P-gp inhibition of 1416 in vitro and in vivo, respectively. One of its potential side effects, calcium antagonism was also evaluated.ResultsResults showed that 1416 showed a similar P-gp inhibition as verapamil in Caco-2 cell monolayer. No significant difference was observed in antitumor enhancement when the optical isomers of 1416 (D-1416 and L-1416) were co-administered with vinblastine. In calcium antagonism, L-1416 showed less calcium inhibition than both D-1416 and verapamil.ConclusionThe novel compound 1416 could significantly increase the antitumor effects of cytotoxic drugs and one of its optical isomers, L-1416, might be more promising due to its potential low calcium antagonism.     

Direct Oral Anticoagulants: New Drugs and New Concepts

Direct oral anticoagulants (DOACs) are approved for multiple thromboembolic disorders and provide advantages over existing agents. As with all anticoagulants, management protocols for the eventuality of bleeding are important. Randomized phase III studies generally show that DOACs have a similar risk of clinically relevant bleeding compared with standard anticoagulants, with reductions in major bleeding in some cases. This may be particularly important in patients with atrial fibrillation, for whom the rate of intracranial hemorrhage was approximately halved with DOACs compared with warfarin. Conversely, the risk of gastrointestinal bleeding may be increased. Specific patient characteristics, such as renal impairment, comedications, and particular aspects of each drug, including the proportion eliminated by the kidneys, must be taken into account when assessing the risk of bleeding. Although routine coagulation monitoring of DOACs is not required, it may be useful under some circumstances. Of the traditional clotting assays, a sensitive and calibrated prothrombin time may be useful for detecting the presence or absence of clinically relevant factor Xa inhibitor concentrations (rivaroxaban or apixaban), but specific anti–factor Xa assays can measure drug levels quantitatively. For dabigatran, the results of an activated partial thromboplastin time test may exclude a clinically relevant pharmacodynamic effect, but a calibrated dilute thrombin time assay can be used for quantification of drug levels. In the event of mild or moderate bleeding, normal hemostatic support measures are recommended. For life-threatening bleeding, use of nonspecific prohemostatic agents may be considered, although clinical evidence is scarce. Specific antidotes are in development.     

P-gp和ABCG2在口腔鳞状细胞癌中的表达及临床病理意义

目的:研究肿瘤耐药相关基因P-糖蛋白(P-gp)和三磷酸腺苷结合转运蛋白G超家族成员(ABCG2)在口腔鳞状细胞癌组织中的表达及其与临床病理特征和预后的关系。方法:应用免疫组化Envision法检测口腔鳞状细胞癌组织76例及正常黏膜组织30例,观察肿瘤耐药相关基因P-gp和ABCG2的表达,同时回顾性研究了这些表达与口腔鳞状细胞癌发生、浸润及转移等临床病理学参数的关系。结果:口腔鳞状细胞癌组织中,P-gp和AB-CG2的表达阳性率分别为88.16%和80.26%。30例正常黏膜组织中,两者的表达率分别为60%和50%,差异有统计学意义(P<0.05)。口腔鳞状细胞癌组织中,P-gp在不同临床分期、不同浸润深度组之间阳性表达率的差异有统计学意义(P<0.05)。ABCG2在不同临床分期、有或无淋巴结转移组之间阳性表达率的差异有统计学意义(P<0.05)。P-gp与ABCG2的表达呈正相关r=0.228(P<0.05)。结论:P-gp和ABCG2在口腔鳞癌的发生发展中可能有协同作用。检测P-gp和ABCG2的表达对口腔鳞癌化疗方案的制定、判断预后有重要指导意义。     

穴位埋药线对难治性癫痫大鼠癫痫样波的发放及大脑海马和颞叶皮质多药耐药相关蛋白MRP1、P-gp表达的影响

目的：探讨穴位埋药线对难治性癫痫大鼠癫痫样波的发放及大脑海马和皮质中多药耐药相关蛋白 MRP1、P-gp表达的影响。方法（1）造模：大鼠海马区注射红藻氨酸（KA）,经过点燃和再次亚惊厥剂量点燃造模,且脑电图检测有癫痫样波发放者筛选为造模成功耐药难治性癫痫模型鼠。（2）分组与处理：普通线组（PTX组）与药线组（YX组）,先埋一侧穴位,间隔15 d后埋对侧穴位。拉莫三嗪组（LTG组）按照人用拉莫三嗪剂量换算灌胃大鼠,每日2次;空白对照组（Normal组）和模型组（Model组）给予灌胃同等体积的蒸馏水,均灌胃30 d。（3）采用VEEG-1518K型数字化视频脑电监测分析系统检测脑波基本节律的波幅与频率变化。（4）标本处理与检测：采用免疫组织化学技术,检测多药耐药相关蛋白MRP1、P-gp在海马与颞叶皮层不同部位的表达。结果各组治疗前比较差异无统计学意义（P＞0.05）;各组治疗后,YX组、LTG 组分别与Model 组、PTX组比较差异有统计学意义（P＜0.05）,YX组与LTG组比较差异无统计学意义（P＞0.05）;与Model组相比,LTG组和YX组干预后能降低致痫鼠EEG 痫波放电持续时间与发放频率以及海马区和颞叶皮质区多药耐药蛋白 MRP1、P-gp 的表达水平（P<0.05或P<0.01）;YX组与PTG组比较差异无统计学意义(P<0.05)。结论（1）埋药线使KA致痫鼠EEG痫波放电持续时间缩短,发放频率减少。（2）KA点燃难治性癫痫模型大鼠大脑海马区存在多药耐药蛋白MRP1、P-gp的表达较皮质区明显升高。（3）埋药线逆转与降低致痫鼠海马区多药耐药蛋白MRP1、P-gp的表达水平,可能是其抗癫痫生物学作用机制之一。     

Prediction of Human Brain Penetration of P-glycoprotein and Breast Cancer Resistance Protein Substrates Using In Vitro Transporter Studies and Animal Models

Four P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) substrates with human cerebrospinal fluid (CSF) concentrations and preclinical neuropharmacokinetics were used to assess in vitro–in vivo extrapolation of brain penetration in preclinical species and the ability to predict human brain penetration. Unbound brain (C_b,u), unbound plasma (C_p,u), and CSF compound concentrations (C_CSF) were measured in rats and nonhuman primates (NHPs), and the unbound partition coefficients (C_b,u/C_p,u and C_CSF/C_p,u) were used to assess brain penetration. The results indicated that for P-gp and BCRP dual substrates, brain penetration was severally impaired in all species. In comparison, for P-gp substrates that are weak or non-BCRP substrates, improved brain penetration was observed in NHPs and humans than in rats. Overall, NHP appears to be more predictive of human brain penetration for P-gp substrates with weak or no interaction with BCRP than rat. Although C_CSF does not quantitatively correspond to C_b,u for efflux transporter substrates, it is mostly within 3-fold higher of C_b,u in rat and NHP, suggesting that C_CSF can be used as a surrogate for C_b,u. Taken together, a holistic approach including both in vitro transporter and in vivo neuropharmacokinetics data enables a better estimation of human brain penetration of P-gp/BCRP substrates.     

Effects of Various Pharmaceutical Excipients on the Intestinal Transport and Absorption of Sulfasalazine,a Typical Substrate of Breast Cancer Resistance Protein Transporter

Breast cancer resistance protein (BCRP) transporter is an efflux transporter that utilizes energy from adenosine triphosphate hydrolysis to push its substrates, regardless of the concentration gradient. Its presence on the apical membrane of the intestinal mucosa is a major obstacle for the intestinal absorption of its substrates. In this study, we examined the effects of various pharmaceutical excipients on the intestinal transport and absorption of sulfasalazine, a BCRP substrate. Four excipients, including 0.05% and 0.075% BL-9EX, 0.01% and 0.05% Brij 97, 0.075% Labrasol, and 0.05% and 0.1% Tween 20 decreased the secretory transport of sulfasalazine in an in vitro diffusion chamber. Further investigation in an in situ closed loop experiment in rats showed that 0.05% and 0.1% BL-9EX and 0.1% Brij 97 effectively enhanced the intestinal absorption of sulfasalazine while maintaining minimal toxicity to the intestinal mucosa. However, 0.1% Brij 97 also increased the intestinal absorption of 5(6)-carboxyfluorescein, a paracellular marker compound. These findings suggest that BL-9EX might effectively inhibit the BCRP-mediated efflux of sulfasalazine in vivo, indicating that BL-9EX could improve the intestinal absorption of sulfasalazine and other BCRP substrates.     

不同性激素对P-糖蛋白表达水平及甲磺酸伊马替尼转运的影响

目的：探讨在ABCB1（1199G/A）重组细胞模型中不同性激素对P-糖蛋白（P-gp）表达水平及甲磺酸伊马替尼转运的影响。方法：将构建的ABCB1_1199G/wt和ABCB1_1199A/mut重组质粒稳定转染入HEK293细胞中,采用RT-PCR和Western Blot分别检测不同性激素对P-gp mRNA和蛋白的表达水平;采用HPLC检测性激素对甲磺酸伊马替尼累积量的影响。结果：浓度梯度的性激素（雌酮、雌三醇雌二酮、黄体酮和睾酮）刺激ABCB1_1199G/wt 和ABCB1_1199A/mut重组细胞后,雌酮和雌三醇能刺激P-gp mRNA和蛋白表达水平,且雌三醇上调ABCB1_1199A/mut mRNA的表达水平显著高于ABCB1_1199G/wt;雌酮和雌三醇可降低甲磺酸伊马替尼在细胞内的累积量,产生对伊马替尼的耐药性。结论：雌酮和雌三醇增加了细胞内P-gp的表达,并促进P-gp介导甲磺酸伊马替尼的转运能力。