Direct Oral Anticoagulant Use in Chronic Kidney Disease and Dialysis Patients With Venous Thromboembolism: A Systematic Review of Thrombosis and Bleeding Outcomes.

OBJECTIVE: To evaluate how treatment with DOACs for VTE affects thrombosis and bleeding outcomes compared to warfarin in CKD and dialysis patients. DATA SOURCES: A literature search was conducted for studies evaluating VTE and bleeding outcomes with DOAC use in CKD and dialysis patients. Searches conducted through EMBASE, MEDLINE/PubMed, Scopus, and Cochrane Central Register of Controlled Trials, from inception to September 22, 2020. STUDY SELECTION AND DATA EXTRACTION: Randomized controlled trials, cohort studies, and case series with ≥10 patients included. DATA SYNTHESIS: From 7286 studies, nine studies met inclusion criteria. There was no significant difference between DOACs (dabigatran, rivaroxaban, apixaban) and warfarin for reducing recurrent VTE and bleeding events in moderate CKD patients. The risk of overall major bleeding increased when the degree of kidney impairment increased. There was no significant difference between apixaban and warfarin for VTE outcomes in dialysis patients. RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE: There continues to be a controversial debate whether it may be more beneficial to use DOACs versus warfarin in CKD/dialysis patients with venous thromboembolism (VTE). The risk vs benefit of using DOACs in the CKD/ESKD population should continue to be evaluated for each individual patient. CONCLUSION: Apixaban may be used cautiously as an alternative in acute VTE treatment in severe CKD patients. Insufficient evidence is available to suggest the use of dabigatran and rivaroxaban in this patient population. The benefit of using DOACs in this population for VTE treatment should be weighed against the potential bleeding risk in patients with CKD.

Evaluation of a real-time polymerase chain reaction method for the quantification of CYP1B1 gene expression in MCF-7 human breast carcinoma cells.

INTRODUCTION: Cytochrome P450 1B1 (CYP1B1) catalyzes the bioactivation of numerous procarcinogens and it is expressed in tumor cells, including human breast cancer cells. To study CYP1B1 gene expression, it is important to have an accurate, precise, reproducible, specific, and quantitative method. METHODS: MCF-7 human breast carcinoma cells were treated with beta-naphthoflavone (BNF; 50 microM), emodin (0.1-3 microM), trans-resveratrol (2.5-20 microM), or 0.1% dimethylsulfoxide (DMSO; vehicle control). Total cellular RNA was isolated and reverse transcribed. cDNA samples were quantified by a fluorescence assay and a constant amount (1 ng) was amplified in a real-time DNA thermal cycler (LightCycler). RESULTS: Melting curve analysis and agarose gel electrophoresis of the amplicons resulted in a single peak and a single band, respectively. The identity of the amplicon was confirmed to be CYP1B1 by sequencing analysis. The standard curve for the real-time PCR amplification of CYP1B1 cDNA was log-linear for at least four orders of magnitude. The limit of quantitation (LOQ) of the assay was 100 copies. At the LOQ, the assay had an accuracy of 8% and a precision of 10%. The intraday (n=4) variability (expressed as percent coefficient of variation) was 9% for a sample with low CYP1B1 mRNA expression (cells treated with 0.1% DMSO; i.e., Sample A) and 3% for a sample with elevated CYP1B1 mRNA expression (cells treated with BNF; i.e., Sample B). The interday (n=4) variability was 16% for Sample A and 15% for Sample B. Emodin increased CYP1B1 mRNA expression in cultured MCF-7 cells (maximal effect of ninefold induction achieved at 1 microM), whereas trans-resveratrol suppressed it (IC(50)=6.6+/-1.0 microM, mean+/-S.E.M., n=3). DISCUSSION: An accurate, precise, reproducible, and specific method is described for the real-time PCR quantification of CYP1B1 gene expression in MCF-7 human breast carcinoma cells.

Transcript profiling of cytochrome P450 genes in HL-60 human leukemic cells: upregulation of CYP1B1 by all-trans-retinoic acid.

All-trans-retinoic acid (ATRA) is used in the treatment of promyelocytic acute leukemia. The biotransformation of this drug is catalyzed by various cytochrome P450 (CYP) enzymes, but relatively little is known about the effect of ATRA on CYP enzyme expression in leukemic cells. In the present study, we conducted transcript profiling of CYP and related genes in cultured HL-60 human promyelocytic leukemic cells and determined the effect of ATRA on the expression of these genes. Reverse transcription-polymerase chain reaction (RT-PCR) analysis with a block-cycler indicated the presence of CYP1B1 but not CYP1A1, CYP2B6, CYP2C8, CYP2C9, CYP3A4, CYP3A5, or CYP26A1 transcript in cultured HL-60 cells. ATRA treatment (0.1-40 microM for 3 days) increased CYP1B1 mRNA levels by up to 3 fold, as determined by a quantitative real-time PCR method. The same ATRA treatment also resulted in the detection of CYP26A1 but not CYP1A1, CYP2B6, CYP2C8, CY2C9, CYP3A4, or CYP3A5 mRNA. Additional experiments showed that phenobarbital increased CYP2B6 mRNA expression and that pregnane X receptor (PXR) but not constitutive androstane receptor (CAR) was detected in HL-60 cells. Overall, our novel findings indicate the upregulation of CYP1B1 by ATRA in HL-60 human promyelocytic leukemic cells shown for the first time to express PXR but not CAR mRNA.