This study examined how the 1199G > A polymorphism in the ABCB1 gene encoding P-glycoprotein (P-gp) affects the protein's expression, ATPase activity, and ability to pump female steroid sex hormones out of LLC-PK1 cells. The ABCB1 (1199G) or ABCB1 (1199A) allele was transfected into cells, which were incubated for 48 h with various hormone concentrations, then analyzed by Western blotting to ex...

BACKGROUND The prodrug clopidogrel requires intestinal absorption by the efflux pump P-glycoprotein MDR1 (multidrug resistant-1), encoded by the ABCB1 gene. Prior studies suggested that a common and functional genetic variant (C3435T, rs1045642) within ABCB1 influences clopidogrel treatment efficacy; however, existing data are highly inconsistent, because other studies failed to replicate this ...

In order to comprehensively screen genetic variants leading to differential expression of the important human ABCB1 gene in the primary drug-metabolizing organ, ABCB1 mRNA expression levels were measured in 73 normal liver tissue samples from Chinese subjects. A set of Tag SNPs. were genotyped. In addition, imputation was performed within a 500 kb region around the ABCB1 gene using the referenc...

The placenta plays an important role in modulating xenobiotic passage from mother to fetus. Studies in mice have demonstrated that placental ABCB1 and ABCG2 can affect the transfer of drugs across the placental barrier, suggesting a role for these transporters in protecting the fetus from environmental toxicants or drugs ingested by the mother during pregnancy. To assess the role of these trans...

AIM ABCB1/MDR1 protein is found in high concentrations on the apical surfaces of colonic epithelial cells. It acts as an efflux pump by transporting toxic endogenous substances, drugs and xenobiotics out of cells. Polymorphisms in the ABCB1/MDR1 gene may either change expression of the ABCB1/MDR1 protein or alter its function, suggesting its possible association with colorectal cancer. Several ...

The ABCB1 gene encodes P-glycoprotein, an ATP-dependent drug efflux pump, which is responsible for drug transport across extra- and intra-cellular membranes. The variability in the expression of ABCB1 may contribute to variable plasma efavirenz concentration which results in variability in the levels of suppression of the human immunodeficiency syndrome virus (HIV). The aim of the study was to ...

In the present in vitro study, we examined the effect of the compound β-elemene on the response of KB-C2 cells overexpressing the ABCB1 transporter to specific antineoplastic compounds. The MTT assay was used to determine the effects of β-elemene in combination with other anticancer drugs on ABCB1-overexpressing cancer cell lines. Furthermore, we used [3H]-paclitaxel accumulation, efflux assay,...

The overexpression of ATP-binding cassette (ABC) transporters is closely associated with the development of multidrug resistance (MDR) in certain types of cancer, which represents a formidable obstacle to the successful cancer chemotherapy. Here, we investigated that cetuximab, an EGFR monoclonal antibody, reversed the chemoresistance mediated by ABCB1, ABCG2 or ABCC1. Our results showed that c...

In this study, we examined the in vitro effects of vemurafenib, a specific inhibitor of V600E mutated BRAF enzyme, on the response of cells overexpressing the ATP binding cassette (ABC) efflux transporters ABCG2, ABCB1, ABCC1 and ABCC10. Vemurafenib, at 5 M and 20 M, produced a significant concentration-dependent increase in the cytotoxicity of paclitaxel in cells overexpressing ABCB1 and ABCC1...

A Postgraduate Year One (PGY1) resident's concerns, limitations, and strengths may be self-identified early in the residency year but are reliant on self-awareness and insight. Program directors commonly find difficulty in identifying a resident's specific knowledge deficits at the beginning of the program. A standardized resident examination can identify limitations early in training and these...