Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.6.3.44 (P-glycoprotein)
 13,344 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The aim of this study was to evaluate the possible effects of carbamazepine, a P-glycoprotein inducer, on fexofenadine pharmacokinetics. Twelve healthy Japanese volunteers (nine males and three females) were enrolled in this study after giving written informed consent. This randomized open-label study consisted of two phases (control and 7-day treatment) with a 2-week washout period. In the control phase, volunteers received 60 mg fexofenadine hydrochloride after an overnight fast. In the treatment phase, carbamazepine was dosed 100 mg three times daily (for a total daily dose of 300 mg) for 7 days, and on Day 7, a single 60-mg dose of fexofenadine was coadministered with a 100-mg dose of carbamazepine. The plasma concentrations and urinary excretion of fexofenadine were measured for 24 hours after dosing. Carbamazepine pretreatment significantly altered fexofenadine pharmacokinetics, decreasing the mean (+/- standard deviation) peak plasma concentration from 176.6 (+/- 82.1) ng/mL to 103.2 (+/- 33.6) ng/mL (P < 0.01) and the area under the plasma concentration-time curve from 1058.4 (+/- 528.7) ng/h/mL to 604.8 (+/- 255.9) ng/h/mL (P < 0.01) without changing the elimination half-life. Relatively, carbamazepine significantly reduced the amount of fexofenadine excreted into the urine from 8.1 (+/- 2.1) mg to 4.5 (+/- 1.4) mg (P < 0.001), although the renal clearance of fexofenadine remained constant between the two study phases. Thus, this study indicates that carbamazepine significantly decreases fexofenadine plasma concentrations, probably as a result of P-glycoprotein induction in the small intestine. Carbamazepine treatment, therefore, is of moderate clinical significance for patients receiving fexofenadine.
Ther Drug Monit 2009 Dec
PMID:Effects of the P-glycoprotein inducer carbamazepine on fexofenadine pharmacokinetics. 1985 15

The human blood brain barrier is responsible for maintaining brain homeostasis and protecting against potentially toxic substances. The ATP-binding cassette drug efflux protein, P-glycoprotein (P-gp) is a key player in actively extruding a wide range of xenobiotics such as opioids from the brain. Because the blood brain barrier is structurally and functionally immature in neonates, opioids may have a greater penetration to the central nervous system. This may influence the efficacy and safety of opioids in the newborn. Understanding the extent of P-gp's expression in the brain in the embryo, fetus, and newborn will facilitate rational opioid use during pregnancy and the neonatal period. This review aims to summarize the current evidence that associates the ontogeny of P-gp and the susceptibility to opioid-induced adverse respiratory effects in neonates. To date, evidence suggests that the expression of P-gp in the human brain is low at birth, contributing to increased susceptibility.
Ther Drug Monit 2014 Dec
PMID:P-glycoprotein in the developing human brain: a review of the effects of ontogeny on the safety of opioids in neonates. 2481 66

BACKGROUND The aim of this study was to evaluate the value of semiquantitative analysis (SQA) of 99mTc-MIBI imaging in predicting early-stage cervical lymph node metastasis (CLNM) in thyroid carcinoma (TC). MATERIAL AND METHODS TC patients (n =106) undergoing surgical resection and histopathological examination were enrolled. All patients received 99mTc-MIBI imaging prior to surgery. P-glycoprotein (P-gp) expression was detected by PT-PCR and immunohistochemistry. With pathological results as the criterion standard, the diagnostic efficiency of 99mTc-MIBI imaging in predicting early-stage CLNM was evaluated. The correlation of P-gp with 99mTc-MIBI imaging was investigated. Logistic regression analysis was applied for analyzing the factors affecting early-stage CLNM. RESULTS The detection rate and misdiagnosis rate of 99mTc-MIBI imaging for early-stage CLNM diagnosis were 87.3% and 12.7%, respectively. Receiver operating characteristic (ROC) curve analysis showed an accuracy of 99mTc-MIBI imaging of 85.85%. Preoperative 99mTc-MIBI scan showed statistical differences between metastasis and non-metastasis groups in early and delayed T/NT and washout rate (all P<0.05). The percentage of P-gp-expressing cells and the expression rate of P-gp gene both exhibited statistical differences between metastasis and no-metastasis groups (both P<0.05). Tumor diameter, lesion distribution, the percentage of P-gp-expressing cells, and the expression rate of P-gp gene were risk factors for CLNM (all P<0.05). CONCLUSIONS 99mTc-MIBI imaging has value in qualitative diagnosis of early-stage CLNM in TC. Tumor diameter, lesion distribution, the percentage of P-gp-expressing cells, and the expression rate of P-gp gene were risk factors for CLNM.
Med Sci Monit 2017 Mar 31
PMID:Diagnostic Value of Semiquantitative Analysis of 99mTechnetium-Methoxyisobutylisonitrile (99mTc-MIBI) Imaging in Predicting Early-Stage Cervical Lymph Node Metastasis of Thyroid Carcinoma. 2836 20

BACKGROUND Mesial temporal epilepsy (MTLE) is the most common type of focal epilepsy in adults, and is often drug-resistant. This study investigated the effects of aquaporins (AQP) inhibitor on multi-drug-resistant protein expression in an MTLE rat model. MATERIAL AND METHODS The MTLE rat model was established by injecting pilocarpine into rats. The MTLE rats were divided into an MTLE-6 h group, an MTLE-12 h group, and an MTLE-24 h group, together with a normal saline group (NS), to examine the AQP4 expression by using Western blot assay and immunohistochemistry assay. The other 18 MTLE model rats were used to observe the effects of the AQP4 inhibitor, acetazolamide, on the multi-drug-resistant protein 1 (MRP1) and P-glycoprotein (Pgp) by using Western blot and immunohistochemistry assays, respectively. RESULTS AQP4 expression was enhanced in hippocampal tissues of MTLE model rats compared to NS rats (P<0.05). More positively stained AQP4 was discovered in hippocampal tissues of MTLE model rats. AQP4 inhibitor significantly decreased multi-drug-resistant protein MRP1 and Pgp expression in the AQP4 inhibitor Interfere group and the AQP4 inhibitor Therapy group compared to the TMLE model group (P<0.05). CONCLUSIONS The present findings confirm that the AQP4 inhibitor, acetazolamide, effectively inhibits the multi-drug-resistant protein, MRP1, and Pgp, in the MTLE rat model.
Med Sci Monit 2017 Dec 08
PMID:Acetazolamide Suppresses Multi-Drug Resistance-Related Protein 1 and P-Glycoprotein Expression by Inhibiting Aquaporins Expression in a Mesial Temporal Epilepsy Rat Model. 2921 17

BACKGROUND Although 5-Flourouracil(5-FU) is used as the first-choice treatment for advanced hepatocellular carcinoma (HCC), it is associated with acquired and intrinsic resistance. Hyperactivation of mTOR signaling has been linked to tumorigenesis and chemoresistance in HCC. The aim of this study was to evaluate and compare the antitumor effects of mTORC1 inhibitor everolimus and mTORC1/2 inhibitor AZD8055 and to examine the interaction between 5-FU and mTORC1/2 inhibitor in HCC. MATERIAL AND METHODS Using cultured HCC cells and mouse xenograft, the antitumor effects of everolimus and AZD8055 were analyzed as mono- and combination therapy with 5-Flourouracil. RESULTS TSC2-deficient HCC cell lines were more sensitive to everolimus and AZD8055. AZD8055, but not everolimus, potently prevented cells from transitioning from G1 phase to S phase in TSC2-high-expressing HCC cells. AZD8055 reduced phosphorylation of both mTORC1 and mTORC2 substrates. In contrast, everolimus reduced the phosphorylation of mTORC1 substrates, but increased the phosphorylation of AKT. Notably, AZD8055, but not everolimus, synergistically enhanced the efficacy of 5-FU via reversing 5-FU-induced upregulation of P-glycoprotein (P-gp). The synergistic antitumor effect of AZD8055 and 5-FU was also observed in a HCC xenograft mouse model. CONCLUSIONS TSC2 in HCC is a promising efficacy-predicting biomarker for the treatment of mTORC1/2 inhibitor. AZD8055 showed stronger antitumor activity than everolimus in TSC2-high-expressing HCC cells. Moreover, the combination of mTORC1/2 inhibitor with 5-FU appears to be a promising option for HCC patients refractory to chemotherapy.
Med Sci Monit 2018 May 03
PMID:Targeting mTORC1/2 Complexes Inhibit Tumorigenesis and Enhance Sensitivity to 5-Flourouracil (5-FU) in Hepatocellular Carcinoma: A Preclinical Study of mTORC1/2-Targeted Therapy in Hepatocellular Carcinoma (HCC). 2972 May 80

BACKGROUND Doxorubicin (DOX) is a potent chemotherapeutic agent used to treat colon cancer. Despite impressive initial clinical responses, drug resistance has dramatically compromised the effectiveness of DOX. However, the underlying mechanisms of chemotherapeutic resistance in colon cancer remain poorly understood. MATERIAL AND METHODS In this study, we compared the expression of miR-222-3p in DOX-resistant colon cancer cells (LoVo/ADR) with the corresponding DOX-sensitive parental cells (LoVo/S) using quantitative real-time PCR. In addition, miR-222-3p inhibitors were infected into LoVo/ADR cell lines and the effects of this treatment were assessed. The Cell Counting Kit 8 assay was employed to verify the sensitivity of colon cancer cell lines to DOX. EdU (5-ethynyl-2'-deoxyuridine) assay, flow cytometry, and in vivo subcutaneous tumorigenesis were used to assess cell proliferation and apoptosis. Transwell and wound healing assays were used to investigate cell migration after adding DOX. Additionally, the expression of forkhead box protein P2 (FOXP2), P-glycoprotein (P-gp) and caspase pathway-associated markers was assessed by western blotting. RESULTS Our results showed that miR-222-3p was upregulated in LoVo/ADR compared with the expression in LoVo/S cells. Additionally, downregulation of miR-222-3p in LoVo/ADR cells increased their sensitivity to DOX, reduced P-gp expression, and activated the caspase pathway. However, the downregulation of FOXP2 could efficiently reverse the effect of miR-222-3p inhibitors on LoVo/ADR cells. CONCLUSIONS Taken together, our results showed that miR-222-3p induced DOX resistance via suppressing FOXP2, upregulating P-gp, and inhibiting the caspase pathway.
Med Sci Monit 2019 Mar 24
PMID:Downregulation of miR-222-3p Reverses Doxorubicin-Resistance in LoVo Cells Through Upregulating Forkhead Box Protein P2 (FOXP2) Protein. 3090 20

Clinical outcomes after organ transplantation have greatly improved in the past 2 decades with the discovery and development of immunosuppressive drugs such as calcineurin inhibitors, antiproliferative agents, and mammalian target of rapamycin inhibitors. However, individualized dosage regimens have not yet been fully established for these drugs except for therapeutic drug monitoring-based dosage modification because of extensive interindividual variations in immunosuppressive drug pharmacokinetics. The variations in immunosuppressive drug pharmacokinetics are attributed to interindividual variations in the functional activity of cytochrome P450 enzymes, UDP-glucuronosyltransferases, and ATP-binding cassette subfamily B member 1 (known as P-glycoprotein or multidrug resistance 1) in the liver and small intestine. Some genetic variations have been found to be involved to at least some degree in pharmacokinetic variations in post-transplant immunosuppressive therapy. It is well known that the frequencies and effect size of minor alleles vary greatly between different races. Thus, ethnic considerations might provide useful information for optimizing individualized immunosuppressive therapy after organ transplantation. Here, we review ethnic factors affecting the pharmacokinetics of immunosuppressive drugs requiring therapeutic drug monitoring, including tacrolimus, cyclosporine, mycophenolate mofetil, sirolimus, and everolimus.
Ther Drug Monit 2020 06
PMID:Significance of Ethnic Factors in Immunosuppressive Therapy Management After Organ Transplantation. 3209 69


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