Effects of Gelsemium elegans Combined with Mussaenda pubescens on Transporter BCRP and Drug-metabolizing Enzyme CYP3A11 / 中国实验方剂学杂志

ObjectiveTo explore the effect of Gelsemium elegans combined with Mussaenda pubescens on efflux transporter breast cancer resistance protein （BCRP） and cytochrome P450 3A11 （CYP3A11） and their attenuation mechanism， and to investigate whether the nuclear receptors were involved in such regulation by intervening it with nuclear receptor activators. MethodC57BL/6 mice were divided into the blank group， G. elegans （GE， 0.25 g·kg-1）group， GE + M. pubescens （MP） （0.25 g·kg-1+10 g·kg-1） group， GE + pregnane X receptor （PXR） activator （rifampicin）（GE + Rif，0.25 g·kg-1+50 mg·kg-1） group， GE + MP + Rif （0.25 g·kg-1+10 g·kg-1+50 mg·kg-1） group， GE + constitutive androstane receptor （CAR） activator （1，4-Bis ［2-（3，5-Dichloropyridyloxy）］ benzene， TCPOBOP）（GE + TCP， 0.25 g·kg-1+0.5 mg·kg-1） group， and GE + MP + TCP （0.25 g·kg-1+10 g·kg-1+0.5 mg·kg-1） group. The medication lasted for 14 successive days. One hour after the last administration， the mice were sacrificed by cervical dislocation and the liver tissue was harvested. The left liver tissue was stained with hematoxylin- eosin （HE） for observing the pathological changes. The right liver tissue was used for BCRP and CYP3A11 mRNA and protein expression detection by real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） and Western blot. ResultThe survival rates of mice in the GE + Rif group， GE group， and GE + MP group were 25% （the lowest）， 40%， and 80%， respectively， and no death was observed in the other groups. Compared with the obvious lesions in the liver cells of the GE group， the pathological changes in liver cells of the GE + MP group were alleviated， while those in the GE + Rif group were worsened. Compared with the GE + Rif group， the GE + MP + Rif group exhibited relieved pathological changes in liver cells. Both the GE + TCP group and the GE + MP + TCP group showed mild liver lesions. The comparison with the GE + MP group revealed that the pathological changes in the GE + MP + TCP group were slightly relieved. Compared with the blank group， the expression of BCRP protein and mRNA in GE group were significantly decreased （P<0.05，P<0.01）.The expression of CYP3A11 protein in GE group were significantly decreased （P<0.01）. Compared with the GE group， the GE + MP group displayed remarkably up-regulated BCRP protein and mRNA expression （P<0.05，P<0.01） and CYP3A11 protein expression （P<0.05）， but slightly up-regulated CYP3A11 mRNA expression. Compared with the GE group， the GE + Rif group exhibited down-regulated BCRP protein expression （P < 0.05）. The protein and mRNA expression levels of BCRP were lower in the GE + MP + Rif group than in the GE + MP group （P<0.05，P<0.01）. The PXR activator rifampicin regulated BCRP before and after the combination of G. elegans with M. pubescens. The CYP3A11 protein and mRNA expression levels in the GE + TCP group were higher than those in the GE group （P<0.05，P<0.01）. Compared with the GE + MP group， the GE + MP + TCP group showed up-regulated CYP3A11 protein and mRNA expression （P<0.05，P<0.01）. CAR activator TCPOBOP also had a regulatory effect on CYP3A11 before and after the compatibility of G. elegans with M. pubescens. ConclusionThe attenuated toxin after the combination of G. elegans with M. pubescens is closely related to the efflux transporter BCRP and the drug-metabolizing enzyme CYP3A11.

Effect and molecular mechanism research of Astragalus membranaceus on inhibiting intestinal absorption of six alkaloids of Aconitum carmichaelii in spleen deficiency rats / 中草药·英文版

Objective: To investigate the effect and the mechanism of Astragalus membranaceus (Huangqi in Chinese, HQ) extract on the intestinal absorption of six alkaloids of Aconitum carmichaelii (Fuzi in Chinese, FZ) in rats with spleen deficiency and provide novel insights into the application of HQ on modulating intestinal barrier. Methods: Four-week-old male Sprague-Dawley rats were fed with Xiaochengqi Decoction to induce the spleen deficiency model for 40 d. Single-pass intestinal perfusion model were used to study the effects of HQ extract on the absorption of alkaloids. Protein expression and mRNA levels of MRP2 and BCRP and tight junction proteins (TJ, including Claudin-1, Occludin and ZO-1) were measured using Western blot and real-time PCR, respectively. The location and expression of TJ protein was also investigated by the immunofluorescence method. Results: Compared with the normal group, the protein expression of MRP2, BCRP and TJ proteins in the model group were significantly down-regulated. After oral administration of HQ, the alkaloid absorption in intestinal villi was inhibited, MRP2, BCRP and TJ proteins were up-regulated, the green fluorescence staining of Claudin-1, Occludin, and ZO-1 was enhanced, and a thick layer of mucus was deposited on the surface of the epithelium of the intestinal cavity. Conclusion: HQ as an intestinal barrier modulator improves the physiological changes of the intestinal environment of spleen deficiency to reduce the absorption of toxic components, leading to a decrease in the absorption of drug-like molecules.

Discovery of novel diarylamides as orally active diuretics targeting urea transporters

Urea transporters (UT) play a vital role in the mechanism of urine concentration and are recognized as novel targets for the development of salt-sparing diuretics. Thus, UT inhibitors are promising for development as novel diuretics. In the present study, a novel UT inhibitor with a diarylamide scaffold was discovered by high-throughput screening. Optimization of the inhibitor led to the identification of a promising preclinical candidate,

Bioengineered miR-328-3p modulates GLUT1-mediated glucose uptake and metabolism to exert synergistic antiproliferative effects with chemotherapeutics

MicroRNAs (miRNAs or miRs) are small noncoding RNAs derived from genome to control target gene expression. Recently we have developed a novel platform permitting high-yield production of bioengineered miRNA agents (BERA). This study is to produce and utilize novel fully-humanized BERA/miR-328-3p molecule (hBERA/miR-328) to delineate the role of miR-328-3p in controlling nutrient uptake essential for cell metabolism. We first demonstrated successful high-level expression of hBERA/miR-328 in bacteria and purification to high degree of homogeneity (>98%). Biologic miR-328-3p prodrug was selectively processed to miR-328-3p to suppress the growth of highly-proliferative human osteosarcoma (OS) cells. Besides glucose transporter protein type 1, gene symbol solute carrier family 2 member 1 (GLUT1/), we identified and verified large neutral amino acid transporter 1, gene symbol solute carrier family 7 member 5 (LAT1/) as a direct target for miR-328-3p. While reduction of LAT1 protein levels by miR-328-3p did not alter homeostasis of amino acids within OS cells, suppression of GLUT1 led to a significantly lower glucose uptake and decline in intracellular levels of glucose and glycolytic metabolite lactate. Moreover, combination treatment with hBERA/miR-328 and cisplatin or doxorubicin exerted a strong synergism in the inhibition of OS cell proliferation. These findings support the utility of novel bioengineered RNA molecules and establish an important role of miR-328-3p in the control of nutrient transport and homeostasis behind cancer metabolism.

Physiologically-based pharmacokinetic predictions of intestinal BCRP-mediated drug interactions of rosuvastatin in Koreans

It was recently reported that the C(max) and AUC of rosuvastatin increases when it is coadministered with telmisartan and cyclosporine. Rosuvastatin is known to be a substrate of OATP1B1, OATP1B3, NTCP, and BCRP transporters. The aim of this study was to explore the mechanism of the interactions between rosuvastatin and two perpetrators, telmisartan and cyclosporine. Published (cyclosporine) or newly developed (telmisartan) PBPK models were used to this end. The rosuvastatin model in Simcyp (version 15)'s drug library was modified to reflect racial differences in rosuvastatin exposure. In the telmisartan–rosuvastatin case, simulated rosuvastatin C(maxI)/C(max) and AUC(I)/AUC (with/without telmisartan) ratios were 1.92 and 1.14, respectively, and the T(max) changed from 3.35 h to 1.40 h with coadministration of telmisartan, which were consistent with the aforementioned report (C(maxI)/C(max): 2.01, AUCI/AUC:1.18, T(max): 5 h → 0.75 h). In the next case of cyclosporine–rosuvastatin, the simulated rosuvastatin C(maxI)/C(max) and AUC(I)/AUC (with/without cyclosporine) ratios were 3.29 and 1.30, respectively. The decrease in the CL(int,BCRP,intestine) of rosuvastatin by telmisartan and cyclosporine in the PBPK model was pivotal to reproducing this finding in Simcyp. Our PBPK model demonstrated that the major causes of increase in rosuvastatin exposure are mediated by intestinal BCRP (rosuvastatin–telmisartan interaction) or by both of BCRP and OATP1B1/3 (rosuvastatin–cyclosporine interaction).

Impact of chrysosplenetin, per se or in combination with artemisinin, on breast cancer resistance protein (Bcrp)/ABCG2 mRNA expression levels in mice small intestine

ABSTRACT Our previous work revealed that chrysosplenetin in combination with artemisinin inhibited in vivo P-glycoprotein (P-gp, one of classic multi-drug resistance proteins) mediated digoxin transportation activity by reversing the upregulated P-gp/Mdr1 mRNA expression levels by artemisinin. Therefore, chrysosplenetin might be a potential artemisinin-resistance reversal agent as a P-gp inhibitor. But it still remains unknown if chrysosplenetin has an impact on another pivotal multi-drug resistance protein, breast cancer resistance protein (Bcrp), which is co-expressed with P-gp in apical membrane of intestinal epithelial cell and overlaps some of the substrates and inhibitors. This study, therefore, further addressed the impact of chrysosplenetin, per se or in combination with artemisin, on Bcrp/ABCG2 mRNA expression levels in mice small intestine determined by western blot and real time-quantitative polymerase chain reaction (RT-qPCR) assay. The drugs were intragastrically administrated once per day for 7 days. Novobiocin, a known Bcrp inhibitor, was observed to have no impact on Bcrp/ABCG2 levels with or without artemisinin versus vehicle. Interestingly, artemisinin alone attenuated Bcrp level while chrysosplenetin alone increased it (p < 0.05). Relative mRNA level was significantly decreased when co-used with artemisinin and chrysosplenetin in ratio of 1:2 (p < 0.05). The discrepant results for chrysosplenetin on Bcrp/ABCG2 mRNA expressions might be closely related to the transcriptional or posttranscriptional regulation.

Targeting BCRP/ABCG2 by RNA Interference Enhances the Chemotherapy Sensitivity of Human Colon Cancer Side Population Cells / 华中科技大学学报（医学）（英德文版）

Relapse and metastasis are frequent in colon cancer and may be linked to stem cell characteristics.This study isolated side population (SP) cells from a colon cancer cell line (Colo-320) and examined their self-renewal and differentiation abilities.Compared to non-SP (NSP) cells,SP colon cancer cells were more tumorigenic in vivo and exhibited more invasive characteristics and a greater ability to form colonies.Additionally,more cells were in G0/G1 phase and more highly expressed the multidrug resistance protein BCRP/ABCG2.We achieved enhanced chemotherapy sensitivity by transfecting SP cells with a hairpin-like,small interfering RNA (siRNA) eukaryotic expression plasmid targeting BCRP/ABCG2.

ABCG2 inhibition as a therapeutic approach for overcoming multidrug resistance in cancer.

Breast cancer resistance protein (BCRP, ABCP or MXR)/ATP-binding cassette subfamily G member 2 (ABCG2) was characterized as a multidrug resistance efflux transporter in 1998. ABCG2 physiologically acts as a part of a selfdefence mechanism for the organism; it enhances eliminating of toxic xenobiotic substances and harmful agents in the intestine, as well as through the blood–brain barrier and placenta. ABCG2 recognizes and transports numerous anticancer drugs including conventional chemotherapeutic and new targeted small therapeutic molecules in clinical usage. Development of ABCG2 inhibitors for clinical usage may allow increased penetration of therapeutic agents into sanctuary sites and increases their intestinal absorption. Here we review the mechanisms that modulate MDR mediated by the ABC transporter ABCG2 in normal and cancer cells by different levels including, epigenetic modifications, transcriptional, post-transcriptional, translation and post-translational regulation. Some clinical applications of ABCG2 inhibitors are also explained.

Experimental study of evodiamine on reversing multidrug resistance of K562/Adr cells / 中草药

Objective: To study the effect of evodiamine (EVO) on the proliferation, cell cycle, and multidrug resistance (MDR) of leukemia K562 and K562/Adr cells. Methods: The effect on the proliferation was detected by CCK-8 kit and/or daunorubicin (DNR). The resistance index (RI) and reversal fold (RF) were calculated. The effect of EVO on cell cycle was tested by flow cytometry; Flow cytometry was used to check the fluorescence intensity of DNR. The expression of MDR1 gene in leukemia K562 and K562/Adr cells was detected by q-PCR. The expression of MDR1 and BCRP proteins in leukemia K562 and K562/Adr cells were detected by Western blotting. Results: CCK-8 test results showed that the proliferation of K562 and K562/Adr cells induced by EVO and DNR was inhibited in a dose and time dependent manner. The RI of DNR on K562/Adr cells was 30.54, the RI of EVO on K562/Adr cells was 19.09|, compared with K562 cells; The RF of DNR + EVO on K562/Adr cells was 12.07.The expression of BCRP and MDR1 protein of K562/Adr cells was significantly decreased in K562/Adr cells induced by EVO and DNR. Conclusion: Therefore EVO can effectively reverse the DNR resistance in K562/Adr cells, which may be related to reduce the expression of MDR1 on cell membrane.

BCRP-targeted reverse of multidrug resistance：research progress and drug development / 中国药理学通报

As an important ABC transporter, breast cancer re-sistance protein ( BCRP) plays an important role in tumor multi-drug resistance. Many laboratories are focusing on BCRP to re-verse multidrug resistance. We summarize in the paper the re-search progress on the regulation of BCRP expression, subcellu-lar localization, ATP-dependence, inhibition or modulation of its transport activity and potential clinical treatment strategies in or-der to provide theoretical support and some new research ideas for the reverse of multidrug resistance in clinic.

Regulatory effect of miR-181 a on breast cancer resistance protein / 中国药理学通报

Aim ToinvestigatetheeffectsofmiRNA-181 a on breast cancer resistance protein ( BCRP ) . Methods Bioinformaticspredictedbindingsitesof BCRP mRNA-3ˊUTR region and miR-181 a;further lu-ciferase reporter gene analysis confirmed that miR-181 a could combine with BCRP mRNA-3ˊUTR; qRT-PCR and Western blot detected related mRNA and protein expressionlevels.Results Comparedwithnegative transfection group, after the miR-181a mimic and PGL3-BCRP 3ˊUTR were co-transfected, luciferase ac-tivity was significantly decreased ( P 0. 05 ); after transfecting miR-181 a inhibitor for 48h, compared to the negative group, the expression of miR-181 a in MCF-7 cells was reduced (P0.05).Conclusion miR-181acanregu-late BCRP expression by targeting the BCRP mRNA-3ˊUTR region.

Reversal effect of vatalanib on BCRP-mediated multidrug resistance / 中国药理学通报

Aim To investigate the reversal effect of vatalanib, a novel kinase inhibitor, on multidrug re-sistance in cancer cells and its mechanism. Methods The cytotoxicity and reversal effects of vatalanib were evaluated in both resistant and sensitive tumor cell lines by MTS or SRB assays. The intracellular accumu-lation of fluorescence substrates ( Rh-123 , MX and ADR for P-gp, BCRP, MRP1, respectively) were ana-lysed by flow cytometry. Western blot or qRT-PCR was used to determine the protein or mRNA expression lev-el of BCRP. The effect of vatalanib on ATPase activity of BCRP was determined using crude membranes pre-pared from HEK293/ABCG2 cells. Results Vata-lanib at the nontoxic dose ( 5 μmol · L-1 ) potentially reversed BCRP-mediated MDR in cancer cells, howev-er it had no effect on P-gp or MRP1 mediated MDR. Vatalanib did not alter the intracellular accumulation of MX in HEK 2 9 3 / ABCG 2 , and had no influence on the BCRP-mediated drug efflux. The ATPase assay indica-ted that vatalanib may serve as a substrate of BCRP. Furthermore, vatalanib dramatically suppressed levels of both the protein and mRNA expression of BCRP in concentration-and time-dependent manners. However, reversal concentration of vatalanib had no influence on the total and phosphorylated forms of AKT and ERK1/ 2 in resistant cancer cells. Conclusion Vatalanib could significantly reverse BCRP-mediated MDR with specificity, and its mechanism may correlate with the down-regulation levels of BCRP both mRNA and pro-tein in resistant cancer cells.

Cisplatin-induced up-regulation and enrichment of BCRP and EHD2 on cell surface / 中国肿瘤临床

Objective:To establish the cisplatin-resistant human lung adenocarcinoma cell line A549/(DDP) cisplatin and to study the relationship between EHD2 and drug resistance. Methods:DDP-resistant human lung cancer cell line A549/DDP was established by gradual and stepwise dose enhancement. MTT was used to measure drug sensitivity. Western blot and immunofluorescence were used to evaluate expression and subcellular localization of EHD2 and breast cancer resistance protein (BCRP). Results:The DDP-resistant cell line A549/DDP was established, with a resistance index of 7.6. EHD2 and BCRP expressions both increased and were enriched on the cell surface membrane. Conclusion:Both EHD2 and BCRP expressions were enriched on the resistant cell surface membrane, suggesting that EHD2 endocytic protein stabilizes BCRP and is involved in drug resistance.

Análise da expressão e atividade das moléculas de influxo e de efluxo de drogas em células da leucemia mielóide crônica / Analysis of the expression and activity of drug influx and efflux molecules in chronic myeloid leukemia cells

"A leucemia mielóide crônica (LMC) é caracterizada pela presença da translocação t(9:22) que codifica a proteína quimérica oncogênica BCR-ABL. Imatinibe é uma droga alvo-específica que inibe a atividade tirosina quinase (TK) da proteína BCR-ABL. Entretanto, os níveis intracelulares do imatinibe podem ser alterados pelas proteínas transportadoras de efluxo de drogas: glicoproteína P (Pgp), proteína da resistência em câncer de mama (BCRP) e proteína relacionada à resistência à múltiplas drogas (MRP1), assim como a proteína transportadora de influxo de drogas (OCT1). O objetivo do presente estudo foi analisar a participação dessas proteínas, isoladamente ou em associação, na resistência ao imatinibe em linhagens celulares e células de pacientes com LMC. Para análise da atividade das proteínas transportadoras de efluxo, foi utilizado o fluorocromo rodamina-123 associado ao modulador ciclosporina-A (Rho+CSA) e o pheophorbide A associado ao fumitremorgin C (PhA+FTC), ambos através de citometria de fluxo. A análise dos RNAm dos genes ABCB1, ABCG2 e SLC22A1 que codificam as proteínas Pgp, BCRP e OCT1, respectivamente, foi realizada por PCR em tempo real. A inibição da TK BCR-ABL foi mensurada através dos níveis de fosforilação de CrkL (pCrkL), seu principal alvo de ativação. Observamos uma maior positividade para o ensaio Rho+CSA nas amostras que expressavam Pgp comparada com as que expressavam MRP1, sugerindo menor atividade dessa proteína em pacientes com LMC, ou ainda que tal ensaio possa ser menos específico para a atividade da MRP1. O ensaio PhA+FTC foi capaz de identificar a atividade da proteína BCRP em linhagens celulares e células de pacientes. Níveis reduzidos dos RNAm ABCB1 e SLC22A1, mas não do RNAm ABCG2, foram observados quando comparados com as amostras de indivíduos saudáveis. Não houve correlação entre os níveis da proteína Pgp e do RNAm ABCB1. A expressão de Pgp foi detectada na maioria das amostras de LMC, independente da fase da doença, e não foi associada com o prognóstico desfavorável. Variações nos níveis de expressão da Pgp foram observadas durante a evolução da LMC e relacionadas com o tratamento prévio. O imatinibe foi capaz de aumentar a expressão da Pgp, assim como os níveis do RNAm ABCB1 na linhagem K562-Lucena 1, Pgp+. Além disso, observamos uma maior redução de pCrkL e um maior percentual de morte celular nas células K562, Pgp-, quando comparadas à K562-Lucena 1, evidenciando um possível papel do imatinibe como substrato para a Pgp. Este fármaco também demonstrou ter potencial para funcionar como agente modulador da bomba de efluxo, uma vez que impediu o exporte de Rho das células K562-Lucena 1. Amostras de pacientes resistentes ao imatinibe exibiram altos níveis de atividade das proteínas transportadoras de efluxo de drogas (ensaio Rho+CSA). Nossos dados mostram que a atividade e/ou expressão dos transportadores de efluxo e influxo de drogas encontram-se alterados na maioria dos pacientes com LMC, porém não há correlação com a resposta ao imatinibe e o prognóstico na LMC. Entretanto, o conjunto dos resultados sugere um papel para a Pgp na resistência in vitro ao imatinibe"(AU)

"Chronic myeloid leukemia (CML) is characterized by the presence of the t(9:22) encoding the BCR-ABL chimeric oncogenic protein. Imatinib is a target specific drug that inhibits the activity of the tyrosine kinase (TK) protein BCR-ABL. However, imatinib intracellular concentration may be altered by transporter proteins. It was described that efflux proteins, P-glycoprotein (Pgp), breast cancer resistance protein (BCRP) and multidrug resistance related protein (MRP1), and the influx protein, the organic cation transporter protein (OCT1) may contribute for imatinib clinical resistance. The aim of this study was to evaluate the role of these proteins in imatinib resistance in cell lines and leukemic cells from CML patients. To analyze the activity of the efflux transporter proteins, fluorochrome rhodamine-123 associated with the modulator cyclosporin A (Rho+CSA) and pheophorbide A associated with fumitremorgin C (PhA+FTC) were used by flow cytometry. Analysis of ABCG1, ABCG2 and SLC22A1 genes, that encode the Pgp, BCRP and OCT1 proteins, respectively, was performed by real time PCR. The inhibition of BCR-ABL TK was measured by the levels of CrkL phosphorylation (pCrkL), its main target of activation. We observed a higher positivity for Rho+CSA assay in samples expressing Pgp, when compared with the ones expressing MRP1. These results suggest that patients with CML have lower activity of this protein, or this assay might be less specific to indicate the activity of MRP1. The PhA+FTC assay was able to identify BCRP activity in cell lines and cells from patients. Reduced levels of ABCB1 and SLC22A1, but not ABCG2 mRNA were observed when compared with samples from healthy individuals. There was no correlation between the levels of Pgp protein and ABCB1 mRNA. Pgp expression was detected in most samples of CML, regardless of disease stage and was not associated with poor prognosis. Changes in Pgp expression levels have been observed during the development of CML and were related to pretreatment. Imatinib was able to increase Pgp expression as well as ABCB1 mRNA levels in Pgp+ K562Lucena 1 cells. Moreover, we observed a greater pCrkL reduction and a higher percentage of cell death in Pgp- K562 cells compared to K562-Lucena 1, indicating a possible role of imatinib as a Pgp substrate. This drug has also been shown to have potential as an efflux pump modulating agent, once efflux of Rho was prevented in K562-Lucena 1. Imatinib resistant patient samples exhibited high levels of efflux transporter proteins activity (Rho+CSA assay). Our data show that the activity and / or expression of influx and efflux transporters of drugs are altered in most patients with CML, but no correlation with prognosis and response to imatinib in CML was observed. However, our results suggest a role for Pgp in imatinib resistance"(AU)

Correlation of genetic polymorphism of transporter with resperidone metabolism / 中国药学杂志

OBJECTIVE: To study the relationship between the genetic polymorphisms of the main transporter of risperidone and its pharmacokinetics in Chinese healthy volunteers. METHODS: 2 mg of risperidone was orally administered to 23 healthy Chinese subjects, and blood samples were taken after dosing. The polymorphic alleles of P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) were determined in each subject. The whole blood concentrations of risperidone and 9-hydroxyrisperidone were measured by high performance liquid chromatography/tandem mass spectrometry(HPLC-MS/MS). RESULTS: The AUC0-∞ and ρmax of 9-hydroxyrisperidone in subjects carrying BCRP 421CA/34GA genotype were 66.6% and 51.1% (P =0.011, P =0.017) of other subjects, respectively. The tmax of risperidone was significantly influenced by BCRP C421A and MDR1 G2677T/A (P < 0.05). CONCLUSION: The disposition of 9-hydroxyrisperidone was affected by BCRP genetic polymorphisms. P-gp and BGRP genotype may also play a role in risperidone absorption. Copyright 2012 by the Chinese Pharmaceutical Association.

Clinical significance of expressions of bcl-2 and BCRP in diffuse large B cell lymphoma / 白血病·淋巴瘤

Objective To explore the expression of b-cell lymphoma/leukemia-2 (bcl-2) and breast cancer drug-resistant protein (BCRP) in diffuse large B cell lymphoma (DLBCL) and their correlation. Methods Using flow cytometry (FCM) and semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) assay the expressions of BCRP gene was analysed in 40 DLBCL samples. bcl-2 protein were measured by immunohistochemistry on paraffin-embedded slices in 40 cases of DLBCL. Results The positive expression rate of bcl-2 and BCRP protein were 60.0 % (24/40) and 37.5 % (15/40) in 40 patients with DLBCL respectively. There was significant differences between positive group and negative groups (x2 = 5.7618,P 0.05). Conclusion BCRP may play an important role in DLBCL primary much medicine drug-resistant,thus it may be a useful prediction of chemotherapeutic treatment and risk of relapse. The level bcl-2 expression was closely related with the grade of malignancy and the prognosis of DLBCL. There was no significant correlation between bcl-2 and BCRP gene. The detection of bcl-2 and BCRP gene played an important role in evaluating DLBCL outcome.

The expression of multi-drug resistance gene in breast cancer stem cells and its significance / 肿瘤

Objective: To detect the expression of multi-drug resistance genes MDR 1 and BCRP in breast cancer stem cells and differentiated cells as well as discuss their clinical significance. Methods: The breast cancer stem cells were separated from human primary breast cancer tissue and MCF-7 cells by flow cytometry-based selection on freshly isolated cells. The expressions of MDR 1 and BCRP in different subsets of cells was measured by real-time PCR. Results: Compared with breast cancer differentiated cells, the expressions of MDR 1 and BCRP in breast cancer stem cells were significantly higher (P < 0.01), and the proportion of stem cells markedly increased after chemotherapy (P < 0.01). Conclusion: Compared with breast cancer differentiated cells, breast cancer stem cells have stronger drug-resistance against chemotherapy via over-expression of multidrug resistance genes, which is one of the key factors for failure of chemotherapy and recurrence of breast cancer.

Establishment of a human embryonic kidney epithelial cell line HEK293/BCRP expresses BCRP and its biologicalcharacterization / 肿瘤

Objective: To establish a human multi-drug resistant embryonic kidney epithelial cell line HEK293/BCRP and investigate its biological characterization. Methods: The expression vector containing breast cancer resistance protein (BCRP) gene was constructed and transfected into HEK293 cells mediated by liposomes. The expression of BCRP was detected by RT-PCR, indirect immunofluorescence staining, and flow cytometry. The multidrug resistance index to mitoxantrone was measured by in vitro cytotoxicity test. Efflux of Rbodamine 123 (Rh123) and adriamycin (ADR) was determined by flow cytometry and laser scanning confocal microscopy, respectively. Results: BCRP expression significantly increased at both mRNA and protein levels in HEK293/BCRP cells. The resistance index to mitoxantrone was 112.07 times. The intracellular concentrations of Rb123 decreased by 42.25% and 69.01% after 1.5-h and 3-h efflux, respectively. Laser scanning confocal microscopy showed that the concentration of ADR also decreased. Conclusion: We successfully establish HEK293/BCRP cell line highly expressed BCRP and has cross-resistance to several anti-cancer drugs.

The Roles of Four Multi-drug Resistance Proteins in Hepatocellular Carcinoma Multidrug Resistance / 华中科技大学学报（医学）（英德文版）

The roles of multi-drug resistance protein 1 (MDR1), multi-drug resistance related protein 1 (MRP1), lung resistance protein (LRP) and breast cancer resistance protein (BCRP) in the multi-drug resistance (MDR) of hepatocellular carcinoma (HCC) were studied. By exposing HepG2 cell line to progressively increased concentrations of adriamycin (ADM), HepG2 multi-drug resistant subline (HepG2/ADM) was induced. The MDR index of HepG2/ADM was detected by using MTT.The expressions of the four MDR proteins in the three cell lines (L02, HepG2, HepG2/ADM) were investigated at mRNA and protein levels by real-time RT-PCR and Western blot respectively. Our results showed that when the ADM concentration was under 100 μg/L, HepG2 could easily be induced to be drug-resistant. The IC50 of the HepG2/ADM to ADM was 282 times that of HepG2. The expression of MDR1 and BCRP mRNA in HepG2/ADM cells were 400 and 9 times that of HepG2 cells respectively while there was no difference in the mRNA expressions of MRP1 and LRP. There was no difference between HepG2 and L02 cells in the mRNA expressions of the four genes. At the protein level, the expressions of MDR1, BCRP and LRP but MRP1 in HepG2/ADM were significantly higher than those of HepG2 and L02. Between HepG2 and L02,there was no difference in the expressions of four genes at the protein level. HepG2/ADM is a good model for the study of MDR. The four genes are probably the normally expressed gene in liven The expressions of MDR1 and BCRP could be up-regulated by anti-cancer agents in vitro. The MDR of HCC was mainly due to the up-regulation of MDR1 and BCRP but MRP1 and LRP. These findings suggest they may serve as targets for the reversal of MDR of HCC.