Breast cancer resistance protein-mediated efflux of luteolin glucuronides in HeLa cells overexpressing UDP-glucuronosyltransferase 1A9.

PURPOSE: UDP-glucuronosyltransferases (UGTs) are responsible for the formation of glucuronides of polyphenolic flavonoids. This study investigated the UGT1A9-mediated glucuronidation of luteolin and the kinetics of luteolin glucuronide efflux. METHOD: HeLa cells overexpressing UGT1A9 (HeLa-UGT1A9) were used to determine the kinetics of breast cancer resistance protein (BCRP)-mediated transport of luteolin glucuronides. Human UGT isoforms were used to determine glucuronidation rates. RESULTS: UGT1A9 was found to catalyze the production of four luteolin glucuronides, including three known monoglucuronides and a novel 3', 4'-diglucuronide. Ko143, a potent specific inhibitor of BCRP, significantly inhibited efflux of luteolin monoglucuronides from HeLa1A9 cells and increased their intracellular levels in a dose-dependent manner. The formation of luteolin diglucuronide was observed when intracellular concentration of total monoglucuronides went above 0.07 nM. CONCLUSIONS: Intracellular accumulation of diglucuronide was detected at high monoglucuronide concentrations (>0.07 nM). Diglucuronide production is speculated to be a compensatory pathway for luteolin disposition.

[The Prognosis Assessment Value of Interim 18F-FDG PET/CT Imaging in the Chemotherapy of Diffuse Large B-cell Lymphoma].

OBJECTIVE: To investigate the prognostic value of interim 18F-FDG PET/CT in patients with diffuse large B-cell lymphoma (DLBCL). METHODS: A total of 97 patients with pathologically diagnosed DLBCL at Sichuan Cancer Hospital and Institute from March 2015 to June 2020 were enrolled in this retrospective study. Receiver operating characteristic analysis (ROC) was used to calculate the optimum maximum standard uptake value reduction ratio (△SUVmax%) cut-off value. The prognostic value of △SUVmax% and Deauville five-point scale (5-PS) in patients with DLBCL was compared, and the determined prognostic factors were analyzed. RESULTS: ROC curve indicated that the optimum △SUV max% cut-off value was 74.9%. Patients with △SUVmax%≥74.9% had a lower rate of progression or recurrence than those with △SUVmax% < 74.9% (both P<0.001). Meanwhile, patients with 5-PS score < 4 also had a lower rate of progression or recurrence than those with 5-PS score≥4 (both P<0.001). △SUVmax% and 5-PS had high specificity (83.7% vs 83.7%) and negative predictive value (87.3% vs 84.9%), while low sensitivity (56.0% vs 52.2%) and positive predictive value (53.8% vs 50.0%). △SUVmax% was more sensitive than 5-PS for the corresponding parameters (78.3% vs 76.2%). Univariate analysis showed that Ann Arbor stage, international prognostic index of National Comprehensive Cancer Network (NCCN-IPI), △SUVmax% and 5-PS were associated with TTP and PFS (all P<0.001). Multivariate analysis showed that △SUVmax% was an independent predictor of TTP and PFS (P=0.031, P=0.023). CONCLUSION: Both 5-PS and △SUVmax% can be used to evaluate the prognosis of DLBCL patients, but the predictive value of △SUVmax% is superior to that of 5-PS.

Multiple Primary Osseous B-Lymphoblastic Lymphoma/Leukemia Shown on Bone Scintigraphy.

ABSTRACT: Primary osseous B-lymphoblastic lymphoma/leukemia is very rare, especially multiple bones involved. Herein, we reported the bone scintigraphy findings in a 16-year-old adolescent boy with a 20-day history of right thigh pain caused by B-lymphoblastic lymphoma/leukemia. Multiple abnormal MDP-avid foci were noted on 99mTc-MDP bone scintigraphy. Interestingly, the CT images of corresponding lesions were unrevealing. Finally, the B-lymphoblastic lymphoma/leukemia was confirmed by pathology and immunohistochemistry.

Drug-Metabolizing Activity, Protein and Gene Expression of UDP-Glucuronosyltransferases Are Significantly Altered in Hepatocellular Carcinoma Patients.

UDP-glucuronosyltransferases (UGTs), the most important enzymes in body detoxification and homeostasis maintaining, govern the glucuronidation reaction of various endogenous and environmental carcinogens. The metabolic function of UGTs can be severely influenced by hepatocellular carcinoma (HCC), the fifth prevalent and third malignant cancer worldwide. Particularly in China, HBV-positive HCC account for approximately 80% of HCC patients. But rare papers addressed the alteration on the metabolism of UGTs specific substrates, translational and transcriptional activity of UGTs in HBV-positive HCC patients. In present study, we choose the main UGT isoforms, UGT1As, UGT1A1, UGT1A9, UGT1A4 and UGT2B7, to determine the alterations of metabolic activity, protein and gene expression of UGTs in HBV-positive HCC. The corresponding specific substrates such as genistein, SN-38, tamoxifen, propofol and zidovudine were utilized respectively in UGTs metabolic activity determination. Furthermore, the plausible mechanism responsible for UGTs alterations was addressed by analyzing the protein and gene expressions in tumor and the adjacent normal tissues in HBV-positive HCC. The results revealed that in the tumor human liver microsomes (HLMs), either V(max) (maximum reaction rate, R(max) for UGT1A1) or the clearance rates (V(max)/K(m), Clint) of UGT1A, UGT1A1, UGT1A4, UGT1A9 and UGT2B7 were significant lower than those of in the adjacent normal HLMs. Subsequently, the relative protein and gene expressions of these isoforms were notably decreased in most of tumor tissues comparing with the adjacent normal tissues. More interestingly, in tumor tissues, the metabolic activity reduction ratio of each UGT isoform was closely related to its protein reduction ratio, indicating that decreasing protein level would contribute to the reduced metabolic function of UGTs in HBV-positive HCC. In summary, our study firstly determined the alteration of UGT function in HBV-positive HCC patients, which would provide an important insight for toxicity or efficacy determination of chemotherapeutic drugs, and even bring a new strategy for clinical regimen in the health cares for the relative patients.

Pharmacokinetic characterization of oxymatrine and matrine in rats after oral administration of radix Sophorae tonkinensis extract and oxymatrine by sensitive and robust UPLC-MS/MS method.

The purpose of this study is to systematically investigate the pharmacokinetic (PK) behaviors of radix Sophorae tonkinensis (S. tonkinensis) using oxymatrine (OMT) and matrine (MT) as the target markers (2 mg/kg OMT and 1.3 mg/kg MT, oral administration). The PK characteristics in radix S. tonkinensis extracts were also compared with those of pure OMT. A fast ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed. OMT absorption was very fast, and no significant differences were observed (p>0.05) in tmax, CL, and t1/2 for both pure OMT and extracts. Cmax and AUC0→∞ of pure OMT were significantly higher than those of S. tonkinensis extracts (Cmax, 61.64±6.65 vs. 43.24±10.14 ng/mL; AUC, 9894.48±2234.99 vs. 4730.30±3503.8 min ng/mL) (p<0.05). However, the absolute OMT bioavailability of pure OMT was higher than that of the compound in radix S. tonkinensis extracts (6.79±2.52% vs. 1.87±2.66%). By contrast, the bioavailability of total alkaloids (OMT+MT) after pure OMT administration was 81.14±8.83%, similar to that of radix S. tonkinensis extracts (69.36±17.37%) (p>0.05). It was presumed that OMT absorption has no effect on the bioavailability of the two alkaloids. Other constituents in radix S. tonkinensis extracts can influence the transformation of OMT to MT, which directly leads to variations in the PK behavior of OMT. In addition, the protein binding of OMT and MT in plasma was very low (4.80%-8.95% for OMT, 5.10-10.55% for MT). In conclusion, OMT in radix S. tonkinensis extracts exhibits different PK behaviors with pure OMT through the transformation of OMT to MT due to other complex ingredients.

Monoester-Diterpene Aconitum Alkaloid Metabolism in Human Liver Microsomes: Predominant Role of CYP3A4 and CYP3A5.

Aconitum, widely used to treat rheumatoid arthritis for thousands of years, is a toxic herb that can frequently cause fatal cardiac poisoning. Aconitum toxicity could be decreased by properly hydrolyzing diester-diterpene alkaloids into monoester-diterpene alkaloids. Monoester-diterpene alkaloids, including benzoylaconine (BAC), benzoylmesaconine (BMA), and benzoylhypaconine (BHA), are the primary active and toxic constituents of processed Aconitum. Cytochrome P450 (CYP) enzymes protect the human body by functioning as the defense line that limits the invasion of toxicants. Our purposes were to identify the CYP metabolites of BAC, BMA, and BHA in human liver microsomes and to distinguish which isozymes are responsible for their metabolism through the use of chemical inhibitors, monoclonal antibodies, and cDNA-expressed CYP enzyme. High-resolution mass spectrometry was used to characterize the metabolites. A total of 7, 8, and 9 metabolites were detected for BAC, BMA, and BHA, respectively. The main metabolic pathways were demethylation, dehydrogenation, demethylation-dehydrogenation, hydroxylation and didemethylation, which produced less toxic metabolites by decomposing the group responsible for the toxicity of the parent compound. Taken together, the results of the chemical inhibitors, monoclonal antibodies, and cDNA-expressed CYP enzymes experiments demonstrated that CYP3A4 and CYP3A5 have essential functions in the metabolism of BAC, BMA, and BHA.

[Effect of IL-1 receptor antagonist on cell apoptosis in rat corneal grafts].

AIM: To observe the apoptosis of cells in rat corneal grafts at acute rejection phase and explore the effects of IL-1 receptor antagonist (IL-1ra) on cell apoptosis. METHODS: The penetrating corneal transplantation model was established. Corneal grafting was divided into four groups, namely, normal Wistar rat control group (no grafting, group A), isograft (Wistar rat-->Wistar rat, group B), allograft (Wistar rat-->SD rat) with normal saline treatment (group C) and allograft (Wistar rat-->SD rat) with IL-1ra treatment (group D). Cell apoptosis in corneal grafts was detected by TUNEL staining at 7 d, 10 d and 14 d after transplantation, and an automatic image analyzer was used to analyze the results, which were expressed as positive unit (PU). The changes of cellular ultrastructure in corneal grafts were observed under transmission electron microscope. RESULTS: (1)The average survival time of corneal grafts in C and D groups was (10.38+/-1.85) d and (13.56+/-1.94) d, respectively, with significant difference (P<0.01). (2)As compared with normal and non-rejected corneas, cell apoptosis and necrosis commonly existed in corneal grafts which rejection had occur. (3)In normal corneas, there were merely a very small number apoptotic cells in epithelial laminal, and apoptotic cells were found hardly in stromal laminal and endothelial cell layers. However, sporadic apoptotic cells were found in all layers of corneal grafts in B, C and D groups at 10 d after transplantation, the average PU being of no notably difference (P>0.05). Apoptosis obviously increased in nearby regions of wound and central area of corneal grafts in C and D groups, especially in C group. The apoptotic cells were distributed mainly in basal layer of epithelial cells and stroma of superficial layer. CONCLUSION: Cell apoptosis plays an important role in corneal graft rejection reaction. IL-1ra treatment can prolong the survival time of corneal grafts by means of suppression of cell apoptosis in corneal grafts.