Gadoxetic disodium-enhanced MRI to characterize T1 relaxation values and expression level of organic anion transporters and multidrug resistance protein on hepatocyte surface membrane of normal C57BL/6 mice / 中华肝脏病杂志

Objective@#The characteristics of T1 relaxation values and the expression levels of organic anion transport system (OATP) and multidrug resistance protein carrier (MRP) on hepatocyte surface membrane were quantitatively studied to evaluate liver function in normal C57BL/6 mice with gadoxetic disodium-enhanced MRI.@*Methods@#Ten 6-weeks-old, normal C57BL/6 mice were included in this study. Gadoxetic disodium- enhanced MRI examination was performed. Longitudinal relaxation time images before and 20 min after contrast injection (hepatobiliary-specific phase) were acquired. T1-relaxation time, T1 relaxation time decline rate (△T) and rapid initial enhancement slope percentage in the first-pass study of the liver parenchyma before and after administration of gadoxetate disodium were measured. Liver parenchyma specimens were detected by Western blotting and the values ​​of OATP1, MRP2, and MRP3 were recorded. Statistical results were expressed in mean.@*Results@#The mean T1 relaxation time of 10 normal C57BL/6 mice before and after enhancement was 659.13 ± 24.07, and 408.87 ± 27.21 ms. The mean T1 relaxation time decline rate and rapid initial enhancement slope percentage in the first-pass study was 37.12% ± 4.95% and 4.14% ± 0.96% ms. Furthermore, the mean value of OATP1, MRP2 and MRP3 were 29 952.1 ± 11 475.2, 34 376.4 ± 33 228.4 and 357 308.9 ± 64 646.5.@*Conclusion@#T1-relaxation values, T1 relaxation time decline rate and rapid initial enhancement slope percentage in the first-pass study before and after gadoxetic disodium-enhanced MRI were determined in normal C57BL/6 mice as well as quantitative values of OATP1, MRP2 and MRP3 at the molecular level on the hepatocyte surface membrane were helpful for liver injury model with control study.

Effect of different concentrations of Gegen Qinlian decoction on expression of P-glycoprotein and multi-drug resistance protein transporter in Caco-2 cells / 中国中药杂志

To investigate the effects of Gegen Qinlian decoction on the expression of P-glycoprotein (P-gp) and multi-drug resistance protein (MRP) in epithelial cells of human colon adenocarcinoma Caco-2 cells．The effects of different concentrations of Gegen Qinlian decoction on the expression levels of p-gp and MRP1-6 mRNA in Caco-2 cells were detected by real time quantitative reverse transcriptase PCR (qRT-PCR).12 h after drug treatment (5.00 g·L⁻¹), the expression levels of MDR1 and MRP1-6 were significantly down-regulated at concentration of 5.00 g·L⁻¹; the mRNA expression levels of MDR1，MRP1，MRP2，MRP4，MRP5 and MRP6 were significantly down-regulated at concentration of 2.50 g·L⁻¹; only the expression levels of MRP2 and MRP5 were significantly affected at concentration of 1.00 g·L⁻¹. The results showed that the expression levels of MDR1 and MRP1-6 mRNA in Caco-2 cells could be down-regulated in a dose-dependent manner. Gegen Qinlian decoction may reduce drug efflux by down-regulating the mRNA expression of cell transporters in Caco-2 cell, and increase the time of drug action, thereby enhancing the bioavailability of chemotherapeutic drugs.

Chemoresistance of multi-drug resistance malignant glioma cells mediated by DNA-PKcs and its molecular mechanism / 吉林大学学报(医学版)

Objective:To obesrve the influence of DNA-PKcs in the chemoresistance of multi-drug resistance malignant glioma cells,and to explore its molecuIar mechanism in chemoresistance.Methods:siRNA was used to construct the DNA-PKcs knockdown human glioma U251 cell line;Western blotting method was used to detect the expressions of DNA-PKcs in U251 cells (U251 cells), doxorubicin (ADM)resistant U251 cells (U251/ADM cells),DNA-PKcs knockdown and ADM resistant U251 cells (U251/ADM/siDNA-PKcs cells).CCK8 method was used to detect the cell proliferation activity in three groups;Western blotting method was used to detect the expressions of MDR1, pNF-κB/p6, total Akt, pAkt/T308 and pAKT/S473 in the cells in three groups. Results:The expression level of DNA-PKcs in U251/ADM cells was significantly higher than those in U251 cells and U251/ADM/siDNA-PKcs cells (P 0.05).Conclusion:DNA-PKcs can significantly enhance the chemoresistance of multi-drug resistance malignant glioma cells,the underlying mechanism is related to up-regulation of pAKT/S473,pNF-κB/p65 and MDR1 expressions.

Significance and dynamic expression of P-glycoprotein in status epilepticus rats / 实用医学杂志

Objective To investigate the dynamic expression of the drug resistance protein P-glycoprotein (P-gp) within 72 hours in the pentylenetetrazol (PTZ)-induced status epilepticus (SE) model, and to identify the optimal detection time to inhibit P-gp. Methods mRNA and protein expressions of P-gp in rats hippocampal tissue were detected by using immunohistochemistry , RT-qPCR and Western blot at different time points after modeling (0, 3, 6, 12, 24, 48, 72 h). Results The mean density of P-gp protein in the hippocampus of status epilepticus model was 0.325 1 ± 0.008 2 at 24 h, and was 0.396 3 ± 0.016 8 at 48 h, which were consistently higher than those of the control group (P < 0.05, P < 0.01, respectively). Results of qRT-PCR showed that MDR1a expression was significantly upregulated at 24 h and at 48 h (P < 0.05, P < 0.01, respectively). Western blot assay revealed that P-gp protein was also significantly increased at 48 h after seizures (P < 0.05). Conclusions The upregulation of P-gp after SE peaked at 48 h, which maybe the optimal detection time to detect drug resistant after SE.

Expressions of resistance proteins P-gp, BCRP and LRP: A comparison between primary and metastatic breast carcinoma / 第二军医大学学报

Objective to investigate the differences n expressions of P-glycoprotein (P-gp), breast cancer drug resistance protein (BCRP) and pulmonary resistance protsnn (LRP) between psimary breast careinoma and metastatic lymph nodes. Methods The expressions of P-gp, BCRP and LRP in breast cancer tissues, including 126 primary carcinoma and 66 metastasis lymph nodes, were determined immunohistochemically on formalin-fixed, paraffin-embedded tumor sections. Results (1)The positive expression rates of P-gp, BCRP and LRP were 41. 27% (52/126), 38. 89% (49/126), and 65. 87% (83/126) in primary breast carcinoma, and were 59. 09% (39/66), 63. 64%(42/66),and 60. 61% (40/66) n metastatic lymph nodes, respctively. The posiiive rates of P-gp and BCRP in the metastatic lymph nodes were significantly higher than those in primary cancer iissue(P0. 05). (2) There was a poor consistency in P-gp and BCRP expressoon between the psimary and metastatic sites(P0. 05). (3) The co-expresion rate of two resistance proteins in primary breast carcinoma was 35. 71%(45/126), of three resistance proteins was 15. 08%(19/ 126), and of two or three resistance proteins was 50. 79% (64/126), being significantly higher than that of a single protein 33. 33% (42/126,P<0. 05). The co-expression rate of two resistance proteins in metastasis lymph nodes was 53. 03% (35/66), which was significantly higher than that of a single protein 27. 27% (18/66, P < 0. 05). The co-expression rate of three resistance proteins was 16. 67%(11/66), two or three resistance proteins was 69. 70%(46/66), which was significantly higher than that of a single protein (P<0. 01). Both the co-expresion levels of two resistance proteins and two or three resistance proteins in metastatic lymph nodes were significantly higher than those in primary cancer (P<0. 05). (4)Kaplan-Meier analyses revealed that patients with P-gp, BCRP and LRP expressed in the metastatic lymph nodes had a lower 5-year survival rate compared with patients whose primary breast cancer being positive for them. Conclusion The expression of P-gp and BCRP is different between the primary and metastatic breast cancer sites, and there is no signAcant difference in LRP expression. Coordination of multi-protein expression is a major feature of resistance. Metastasis lymph nodes may have a stronger resistance.