Endoscopic obstruction predominantly occurs in right-side colon cancer and endoscopic obstruction with tumor size ≤ 5 cm seems poor prognosis in colorectal cancer.

Background: Endoscopic obstruction (eOB) is associated with a poor prognosis in colorectal cancer (CRC). Our study aimed to investigate the association between tumor location and eOB, as well as the prognostic differences among non-endoscopic obstruction (N-eOB), eOB with tumor size ≤ 5 cm, and eOB with tumor size > 5 cm in non-elderly patients. Methods: We retrospectively reviewed the clinicopathological variables of 230 patients with CRC who underwent curative surgery. The multivariable logistic regression model was used to identify risk factors for eOB. The association between eOB with tumor size ≤ 5 cm and disease-free survival (DFS) was evaluated using multivariate cox regression analysis. Results: A total of 87 patients had eOB while 143 had N-eOB. In multivariate analysis, preoperative carcinoembryonic antigen (p = 0.014), tumor size (p = 0.010), tumor location (left-side colon; p = 0.033; rectum; p < 0.001), and pT stage (T3, p = 0.009; T4, p < 0.001) were significant factors of eOB. The DFS rate for eOB with tumor size ≤ 5 cm was significantly lower (p < 0.001) in survival analysis. The eOB with tumor size ≤ 5 cm (p = 0.012) was an unfavorable independent factor for DFS. Conclusions: The patients with eOB were significantly associated with right-side colon cancer as opposed to left-side colon cancer and rectal cancer. The eOB with tumor size ≤ 5 cm was an independent poor prognostic factor. Further studies are needed to target these high-risk groups.

A modified nucleoside O6-methyl-2'-deoxyguanosine-5'-triphosphate exhibits anti-glioblastoma activity in a caspase-independent manner.

Resistance to temozolomide (TMZ), the frontline chemotherapeutic agent for glioblastoma (GBM), has emerged as a formidable obstacle, underscoring the imperative to identify alternative therapeutic strategies to improve patient outcomes. In this study, we comprehensively evaluated a novel agent, O6-methyl-2'-deoxyguanosine-5'-triphosphate (O6-methyl-dGTP) for its anti-GBM activity both in vitro and in vivo. Notably, O6-methyl-dGTP exhibited pronounced cytotoxicity against GBM cells, including those resistant to TMZ and overexpressing O6-methylguanine-DNA methyltransferase (MGMT). Mechanistic investigations revealed that O6-methyl-dGTP could be incorporated into genomic DNA, disrupting nucleotide pools balance, and inducing replication stress, resulting in S-phase arrest and DNA damage. The compound exerted its anti-tumor properties through the activation of AIF-mediated apoptosis and the parthanatos pathway. In vivo studies using U251 and Ln229 cell xenografts supported the robust tumor-inhibitory capacity of O6-methyl-dGTP. In an orthotopic transplantation model with U87MG cells, O6-methyl-dGTP showcased marginally superior tumor-suppressive activity compared to TMZ. In summary, our research, for the first time, underscores the potential of O6-methyl-dGTP as an effective candidate against GBM, laying a robust scientific groundwork for its potential clinical adoption in GBM treatment regimens.

The impacts of CYP3A4 genetic polymorphism and drug interactions on the metabolism of lurasidone.

The aim of this study was to investigate the impacts of 24 variants of recombinant human CYP3A4 and drug interactions on the metabolism of lurasidone. In vitro, enzymatic reaction incubation system of CYP3A4 was established to determine the kinetic parameters of lurasidone catalyzed by 24 CYP3A4 variants. Then, we constructed rat liver microsomes (RLM) and human liver microsomes (HLM) incubation system to screen potential anti-tumor drugs that could interact with lurasidone and studied its inhibitory mechanism. In vivo, Sprague-Dawley (SD) rats were applied to study the interaction between lurasidone and olmutinib. The concentrations of the analytes were detected by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). As the results, we found that compared with the wild-type CYP3A4, the relative intrinsic clearances vary from 355.77 % in CYP3A4.15 to 14.11 % in CYP3A4.12. A series of drugs were screened based on the incubation system, and compared to without olmutinib, the amount of ID-14283 (the metabolite of lurasidone) in RLM and HLM were reduced to 7.22 % and 7.59 %, and its IC50 were 18.83 ± 1.06 µM and 16.15 ± 0.81 µM, respectively. At the same time, it exerted inhibitory effects both through a mixed mechanism. When co-administration of lurasidone with olmutinib in rats, the AUC(0-t) and AUC(0-∞) of lurasidone were significantly increased by 73.52 % and 69.68 %, respectively, while CLz/F was observably decreased by 43.83 %. In conclusion, CYP3A4 genetic polymorphism and olmutinib can remarkably affect the metabolism of lurasidone.

Effect of apatinib on the pharmacokinetics of tramadol and O-desmethyltramadol in rats.

Since the combination of anticancer drugs and opioids is very common, apatinib and tramadol are likely to be used in combination clinically. This study evaluated the effects of apatinib on the pharmacokinetics of tramadol and its main metabolite O-desmethyltramadol in Sprague-Dawley (SD) rats and the inhibitory effects of apatinib on tramadol in rat liver microsomes (RLMs), human liver microsomes (HLMs) and recombinant human CYP2D6.1. The samples were determined by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The in vivo results showed that compared with the control group, apatinib increased the AUC(0-t), AUC(0-∞) and Cmax values of tramadol and O-desmethyltramadol, and decreased the values of VZ/F and CLz/F. In addition, the MRT(0-t), MRT(0-∞) values of O-desmethyltramadol were increased. In vitro, apatinib inhibited the metabolism of tramadol by a mixed way with IC50 of 1.927 µM in RLMs, 2.039 µM in HLMs and 15.32 µM in CYP2D6.1. In summary, according to our findings, apatinib has a strong in vitro inhibitory effect on tramadol, and apatinib can increase the analgesic effect of tramadol and O-desmethyltramadol in rats.

MAT1A Suppression by the CTBP1/HDAC1/HDAC2 Transcriptional Complex Induces Immune Escape and Reduces Ferroptosis in Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) remains a significant health burden globally due to its high prevalence and morbidity. C-terminal-binding protein 1 (CTBP1) is a transcriptional corepressor that modulates gene transcription by interacting with transcription factors or chromatin-modifying enzymes. High CTBP1 expression has been associated with the progression of various human cancers. In this study, bioinformatics analysis suggested the existence of a CTBP1/histone deacetylase 1 (HDAC1)/HDAC2 transcriptional complex that regulates the expression of methionine adenosyltransferase 1A (MAT1A), whose loss has been associated with ferroptosis suppression and HCC development. Thus, this study aims to investigate the interactions between the CTBP1/HDAC1/HDAC2 complex and MAT1A and their roles in HCC progression. First, high expression of CTBP1 was observed in HCC tissues and cells, where it promoted HCC cell proliferation and mobility while inhibiting cell apoptosis. CTBP1 interacted with HDAC1 and HDAC2 to suppress the MAT1A transcription, and silencing of either HDAC1 or HDAC2 or overexpression of MAT1A led to the inhibition of cancer cell malignancy. In addition, MAT1A overexpression resulted in increased S-adenosylmethionine levels, which promoted ferroptosis of HCC cells directly or indirectly by increasing CD8+ T-cell cytotoxicity and interferon-γ production. In vivo, MAT1A overexpression suppressed growth of CTBP1-induced xenograft tumors in mice while enhancing immune activity and inducing ferroptosis. However, treatment with ferrostatin-1, a ferroptosis inhibitor, blocked the tumor-suppressive effects of MAT1A. Collectively, this study reveals that the CTBP1/HDAC1/HDAC2 complex-induced MAT1A suppression is liked to immune escape and reduced ferroptosis of HCC cells.

Delivery of hydroxycamptothecin via sonoporation: An effective therapy for liver fibrosis.

Hepatic fibrosis is the common pathway for most chronic liver diseases, characterized by excessive accumulation of extracellular matrix (ECM) proteins. It has been shown that fibrotic ECM significantly hindered passage of nanoparticles. Efforts have been made by decorating degrading enzymes on surfaces of nanosized delivery vehicles to improve drug delivery. However, these strategies are restricted by limiting shelf-life. Inspired by the application of sonoporation in assisting drug delivery through blood-brain barrier and tumor tissues, we investigated whether sonoporation can be an alternative strategy in improving drug delivery for fibrotic diseases. Hydroxycamptothecin (HCPT), a potential drug in treating liver fibrosis, was selected as a model drug to evaluate the drug delivery efficiency and therapeutic effect among three delivery strategies, i.e., (1) injection solution, (2) delivery through liposomes, and (3) delivery via sonoporation. Our study showed that in addition to the improved drug delivery efficiency, the combination of HCPT and sonoporation led to synergistic effect and the mechanisms were investigated. The treatment group of HCPT delivered with sonoporation achieved the most significant attenuation in liver fibrosis among the three delivery strategies.

The geometry-dependent regulation of hepatic stellate cells by graphene oxide nanomaterials.

Nanomaterials are widely used in biomedical applications such as drug delivery, bioimaging, and photothermal therapy. For example, graphene oxide (GO) nanomaterials are among the most popular drug delivery vehicles in treating liver diseases due to their tunable chemical/physical properties, and biocompatibility. However, it has been reported that nanomaterials tend to accumulate in livers. The biophysical impact of the accumulation in liver cells remains unclear, and it may cause the liver fibrosis in the long run. The activation of hepatic stellate cells (HSCs) is one of the key initial steps of liver fibrosis. In this paper, we explored the geometric effect (nanosheets vs. quantum dots) of GO nanomaterials on human HSCs, in terms of cell viability, fibrotic degree, mobility and regulation pathways. Our study showed that GO nanosheets could significantly reduce HSCs cell viability and mobility. The protein expression levels of TGFßRⅡ/Smad2/Smad3 decreased, corresponding to a trend of attenuating fibrotic degree. However, the expression level of α-SMA, a maker protein of fibrosis, increased and contradicted with the projection. Further investigation on mitochondria showed that GO nanosheets disrupted mitochondria membrane and membrane potentials. We found that while modulating fibrotic effect through the TGF-ß pathway, GO nanosheets induced oxidative stress and activated HSCs through reactive oxygen species(ROS)pathway. This was confirmed by the decreased expression level of α-SMA after co-incubation of GO nanosheets and n-acetyl cysteine (NAC) with HSCs. GO quantum dots decreased α-SMA expression level at 100 mg/l, along with decrease in GAPDH expression level and constant expression level of ß-actin. The correlation between GAPDH and α-SMA remains to be explored. Our study suggested that the biophysical impacts of GO nanomaterials on HSCs are geometry-dependent. Both GO nanosheets and quantum dots can be adapted for attenuating liver fibrosis with further investigation on mechanisms.

Reappraisal of the diagnostic value of alpha-fetoprotein for surveillance of HBV-related hepatocellular carcinoma in the era of antiviral therapy.

This study was designed to explore if antiviral treatment influences the performance of serum alpha-fetoprotein (AFP) for hepatocellular carcinoma (HCC) among the high-risk chronic HBV-infected patients. A total of 5936 patients who had evidence of chronic HBV infection were enrolled from four independent centres in this retrospective study, including 1721 chronic hepatitis B (CHB), 2286 liver cirrhosis (LC), 798 HCC within Milan criteria and 1131 HCC beyond Milan criteria patients. Stratified by whether they received treatment or not, the patients were further divided into antiviral and non-antiviral groups. Then, the performance of AFP for discriminating HCC was evaluated. Patients receiving antivirals had significantly lower median levels of AFP compared with the non-antiviral patients (P < .001), and there were significantly less patients with abnormal AFP levels in antiviral groups (P < .001). Antiviral therapy improved the AUROCs of AFP for discriminating HCC within Milan criteria. When setting the cut-off values at 20 ng/mL and 100 ng/mL as surveillance and confirmatory tests respectively for HCC among patients receiving antiviral treatment, AFP exhibited a significantly higher sensitivity than those of 200 ng/mL and 400 ng/mL, which are currently recommended by some guidelines, without compromising specificity. Further analysis in antiviral patients revealed that serum AFP had better performance for discriminating HCC within Milan criteria in ALT ≤ 1ULN patients than that in ALT > 1ULN patients. In conclusion, in the era of antiviral therapy, serum AFP's surveillance performance was substantially improved for HCC within Milan criteria among the high-risk population of CHB and LC patients.

Dahuang Zhechong pill attenuates CCl4-induced rat liver fibrosis via the PI3K-Akt signaling pathway.

It is well characterized that activated hepatic stellate cells (HSCs) exert critical functions in accelerating the progression of liver fibrosis. Previous studies have indicated that Dahuang Zhechong pill (DHZCP), a traditional Chinese herbal medicine, is capable of inactivating HSCs and thus attenuate the formation of liver fibrosis in rats. However, pharmacological mechanisms of DHZCP in alleviating liver fibrosis remain unclear. This study aims to investigate the antifibrotic role of DHZCP through inhibiting the phosphatidylinositol 3-kinase (PI3K)-protein kinase B (Akt) pathway. DHZCP was found to significantly suppresses extracellular matrix formation and immune cell infiltration, thus alleviating liver fibrosis symptoms in the in vivo model. Moreover, DHZCP reduced serum levels of transforming growth factor ß1 and tumor necrosis factor-α in rats with liver fibrosis. DHZCP treatment remarkably downregulated protein levels of PI3K and phosphorylated Akt, as well as fibrosis markers. In vitro experiments further demonstrated that DHZCP markedly suppressed HSCs proliferation by downregulating PI3K/Akt, which exerted a synergistic effect with the PI3K inhibitor LY294002. To sum up, our results confirmed that DHZCP exerted an antifibrotic effect in the animal model through inactivating the PI3K/Akt pathway, thus protecting rats from liver injury.

Cytochrome P450-Mediated Metabolic Characterization of a Mono-Carbonyl Curcumin Analog WZ35.

WZ35 is a monocarbonyl analog of curcumin, which had been proved advantage over curcumin in chemical stability and antitumor activity. However, its pharmacokinetic profile has not been determined. In the present study, an ultraperformance liquid chromatography-tandem mass spectrometry assay was developed to detect concentration of WZ35 in rat plasma. Subsequently, pharmacokinetic study showed that the oral bioavailability of WZ35 is 10.56%. Cytochrome P450 (CYP450) plays a major role in metabolizing exogenous substance. The concentration of WZ35 was sharply decreased while incubating with microsome. It's indicated that WZ35 is a substrate of CYP450s. Molecular docking assay showed that WZ35 can combine with CYP2B6 and CYP2C9 to form much more stable complex. The lowest docking energy was generated in complex with CYP2E1. The inhibition of CYP450s by WZ35 was also evaluated. Pan inhibitions of WZ35 on rat CYP3A2, CYP2B1, CYP2C11, CYP2D1, and -CYP2E1 were observed by detecting probe substrates (midazolam, bupropion, tolbutamide, dextromethorphan, chlorzoxazone) and metabolites accordingly. On an average, 80% activities of enzymes were blocked. Mechanistically, the inhibitions of WZ35 on CYP3A2, CYP2B1, CYP2E1 were in a time-dependent manner according to the results of IC50 shift assay. The collective data demonstrated that the oral bioavailability of monocarbonyl analog of curcumin has significantly improved compared to curcumin. It's both the substrate and inhibitor of CYP450s through in a time-dependent mechanism.

Functional characterization of 27 CYP3A4 protein variants to metabolize regorafenib in vitro.

AIM: Regorafenib is a tyrosine kinase inhibitor that is mainly metabolized by CYP3A4. The genetic polymorphism of CYP3A4 would contribute to differences in metabolism of regorafenib. Previously, we had discovered several novel CYP3A4 variants. However, the catalytic characteristics of these 27 CYP3A4 variants on oxidizing regorafenib have not being determined. The purpose of this study was to investigate the catalytic characteristics of 27 CYP3A4 protein variants on the oxidative metabolism of regorafenib in vitro. METHOD: Wild-type CYP3A4.1 or other variants was incubated with 0.5-20 µmol/L regorafenib for 30 minutes. After sample processing, regorafenib-N-oxide, a primary metabolite, was detected by ultra-performance liquid chromatography-tandem mass spectrometry system. RESULT: CYP3A4.20 had no detectable enzyme activity compared with wild-type CYP3A4.1; five variants (CYP3A4.5, .16, .19, .24, .29) exhibited similar clearance value with CYP3A4.1; four variants (CYP3A4.14, .15, .28, .31) displayed increased enzymatic activities, while remaining variants showed markedly decreased intrinsic clearance values. CONCLUSION: This study is the first to investigate the function of 27 CYP3A4 protein variants on the metabolism of regorafenib in vitro, and it may provide some valuable information for further research in clinic.

Effects of ketoconazole, voriconazole, and itraconazole on the pharmacokinetics of apatinib in rats.

We investigated the effect of azole antifungal drugs (ketoconazole, voriconazole, and itraconazole) on the pharmacokinetics of apatinib in rats. The rats in ketoconazole, voriconazole, and itraconazole groups received single-dose apatinib 30 mg/kg after the oral administration of ketoconazole, voriconazole, and itraconazole, respectively. Co-administration of ketoconazole or voriconazole significantly increased the apatinib Cmax and AUC(0-t) and decreased the clearance. Co-administration of itraconazole did not significantly affect the pharmacokinetics parameters of apatinib. It could be concluded that both ketoconazole and voriconazole significantly increase the exposure of apatinib, and affect the pharmacokinetics of apatinib in rat. Apatinib can be co-administered with itraconazole, but ketoconazole and voriconazole should be avoided if possible or be underwent therapeutic drug monitoring of apatinib. A further clinical study should be conducted to investigate the inhibitory effect of azole antifungal drugs on the apatinib plasma concentration.

Liver Stiffness Measurement Can Reflect the Active Liver Necroinflammation in Population with Chronic Liver Disease: A Real-world Evidence Study.

Background and Aims: Non-invasive evaluation of liver necroinflammation in patients with chronic liver disease is an unmet need in clinical practice. The diagnostic accuracy of transient elastography-based liver stiffness measurement (LSM) for liver fibrosis could be affected by liver necroinflammation, the latter of which could intensify stiffness of the liver. Such results have prompted us to explore the diagnosis potential of LSM for liver inflammation. Methods: Three cross-sectional cohorts of liver biopsy-proven chronic liver disease patients were enrolled, including 1417 chronic hepatitis B (CHB) patients from 10 different medical centers, 106 non-alcoholic steatohepatitis patients, and 143 patients with autoimmune-related liver diseases. Another longitudinal cohort of 14 entecavir treatment patients was also included. The receiver operating characteristic (ROC) curve was employed to explore the diagnostic value of LSM. Results: In CHB patients, LSM value ascended with the increased severity of liver necroinflammation in patients with the same fibrosis stage. Such positive correlation between LSM and liver necroinflammation was also found in non-alcoholic steatohepatitis and autoimmune-related liver diseases populations. Furthermore, the ROC curve exhibited that LSM could identify moderate and severe inflammation in CHB patients (area under the ROC curve as 0.779 and 0.838) and in non-alcoholic steatohepatitis patients (area under the ROC curve as 0.826 and 0.871), respectively. Such moderate diagnostic value was also found in autoimmune-related liver diseases patients. In addition, in the longitudinal entecavir treated CHB cohort, a decline of LSM values was observed in parallel with the control of inflammatory activity in liver. Conclusions: Our study implicates a diagnostic potential of LSM to evaluate the severity of liver necroinflammation in chronic liver disease patients.

Evaluation of the inhibition effects of apatinib on human and rat cytochrome P450.

Apatinib, a small molecule anti-angiogenic drug, is proven to be safe and effective for treatment of advanced gastric cancer (AGC). It is also a single drug that significantly prolongs survival after failure of standard chemotherapy for AGC, which has attracted the research interest. The purpose of this study is to evaluate the inhibition effects of apatinib on human and rat cytochrome P450, including CYP3A2/4, CYP2B1/6, CYP2C9/11, CYP2D1/6, and CYP2E1. The IC50 and IC50-shift results indicated that apatinib might not be a time-dependent inhibitor. Apatinib was a weak inhibitor of human CYP2E1 (IC50>10 µM) but inhibited CYP2B6/2B1 and CYP2D6/2D1 in a competitive way (Ki = 3.84/0.59 and 5.41/0.87 µM), and inhibited CYP3A4/3A2 and rat CYP2E1 in a mixed way (Ki = 11.50/1.83 and 13.06 µM). On CYP2C9, apatinb exhibited the noncompetitive inhibition (Ki = 0.71 µM) while it inhibited CYP2C11 uncompetitively (Ki = 3.30 µM).

Determination and pharmacokinetic study of Enasidenib in rat plasma by UPLC-MS/MS.

Enasidenib, an oral product for treating Acute Myeloid Leukemia, has been approved by FDA in Aug, 2017. In this study, we set up an ultra-performance liquid chromatography-mass spectrometry (UPLC-MS/MS) method for measuring Enasidenib and imatinib (internal standard, IS), simultaneously. Enasidenib and imatinib were separated on an ACQUITY UPLC BEH C18 Column (2.1 mm × 50 mm, 1.7 µm, 132 Å). Mass detection was carried out by electrospray ionization in the position mode, and the multiple reaction monitoring transitions were m/z 474.23 → 456.17 and m/z 494.30 → 394.20 for Enasidenib and imatinib, respectively. Linearity (2 - 500 ng·mL-1, R2 > 0.999), precision and accuracy (RE < ±â€¯15%), extraction recovery (≥ 96.69%), matrix effect (≥ 96.47%) and stability (RE < ±â€¯10%) were validated which demonstrated the robustness of our method. This rapid, efficient and reliable UPLC-MS/MS method shows specificity and repeatability of Enasidenib in rat plasma and can be used in further pharmacokinetic studies.

Genome­wide identification of long noncoding RNAs in CCl4­induced liver fibrosis via RNA sequencing.

Liver fibrosis occurs as a result of chronic liver lesions, which may subsequently develop into liver cirrhosis and hepatocellular carcinoma. The involvement of long noncoding RNAs (lncRNAs) in liver fibrosis is being increasingly recognized. However, the exact mechanisms and functions of the majority of lncRNAs are poorly characterized. In the present study, the hepatotoxic substance carbon tetrachloride (CCl4) was employed to induce liver fibrosis in an animal model and agenome­wide identification of lncRNAs in fibrotic liver tissues compared with CCl4 untreated liver tissues was performed using RNA sequencing. Sprague­Dawley rats were treated with CCl4 for 8 weeks. Histopathogical alterations were observed in liver tissues, and serum levels of alanine aminotransferase, aspartate aminotransferase, transforming growth factor­ß1 and tumor necrosis factor­α were significantly higher, in the CCl4­treated group compared with the CCl4 untreated group. RNA sequencing of liver tissues demonstrated that 231 lncRNAs and 1,036 mRNAs were differentially expressed between the two groups. Furthermore, bioinformatics analysis demonstrated that the differentially expressed mRNAs were predominantly enriched in 'ECM­receptor interaction', 'PI3K­Akt signaling pathway' and 'focal adhesion' pathways, all of which are essential for liver fibrosis development. Validation of 12 significantly aberrant lncRNAs by reverse transcription­quantitative polymerase chain reaction indicated that the expression patterns of 11 lncRNAs were consistent with the sequencing data. Furthermore, overexpression of lncRNA NR_002155.1, which was markedly downregulated in CCl4­treated liver tissues, was demonstrated to inhibit HSC­T6 cell proliferation in vitro. In conclusion, the present study determined the expression patterns of mRNAs and lncRNAs in fibrotic liver tissue induced by CCl4. The identified differentially expressed lncRNAs may serve as novel diagnostic biomarkers and therapeutic targets for liver fibrosis.

Functional Characterization of 22 CYP3A4 Protein Variants to Metabolize Ibrutinib In Vitro.

Cytochrome P450 3A4 (CYP3A4) is quantitatively the most important P450 enzyme in adults. It is suggested that CYP3A4 genetic polymorphisms may influence the rate of the metabolism and elimination of CYP3A4 substrates in human beings. Ibrutinib is an anticancer drug and primarily metabolized by CYP3A4. The aim of this study was to systematically investigate the effects of 22 CYP3A4 protein variants on the metabolism of ibrutinib in vitro. When compared with wild-type CYP3A4.1, two variants (CYP3A4.17 and CYP3A4.24) had no detectable enzyme activity; five variants (CYP3A4.10, .11, .18, .23 and .33) exhibited no significant differences; another five variants (CYP3A4.3, .4, .9, .19 and .34) showed increased intrinsic clearance values, while the remaining nine variants (CYP3A4.2, .5, .14, .15, .16, .28, .29, .31 and .32) displayed decreased enzymatic activities in different degrees. As the first study of 22 CYP3A4 protein variants in ibrutinib metabolism, these comprehensive data may help in the clinical assessment of the metabolism and elimination of ibrutinib and also offer a reference to the personalized treatment of ibrutinib in clinic.

Determination of lesinurad in rat plasma by a UHPLC-MS/MS assay.

Lesinurad is an oral inhibitor of urate-anion exchanger transporter 1 and has been approved by the US Food and Drug Administration for combination therapy with a xanthine oxidase inhibitor for the treatment of hyperuricemia associated with refractory gout. In the present study, a sensitive and specific ultra high-performance liquid chromatography with tandem mass spectrometry assay was established and verified for the determination of lesinurad in rat plasma and was described in details for the first time. Chromatographic separation of lesinurad and diazepam (internal standard, IS) was performed on a Rapid Resolution HT C18 column (3.0 × 100 mm, 1.8 µm) using methanol-water (70:30, v/v) as the mobile phase at a flow rate of 0.3 mL/min. Lesinurad and IS were extracted from plasma by liquid-liquid extraction using ethyl acetate. The mass spectrometric detection was carried out using an electrospray ionization source in positive mode. Multiple reaction monitoring was used for quantification of the precursor to product ion at m/z 405.6 â†’ 220.9 for lesinurad and m/z 285.1 â†’ 192.8 for IS. The assay was well validated for selectivity, accuracy, precision, recovery, linearity, matrix effects, and stability. The verified method was applied to obtain the pharmacokinetic parameters and concentration-time profiles for lesinurad after oral/intravenous administration in rats. The study might provide an important reference and a necessary complement for the qualitative and quantitative evaluation of lesinurad.

A reliable and stable method for determination of brigatinib in rat plasma by UPLC-MS/MS: Application to a pharmacokinetic study.

Brigatinib is the second-generation anaplastic lymphoma kinase - inhibitor in non-small cell lung cancer and it can overcome the crizotinib-resistance. Chromatographic separation was carried out on an Acquity Ultra Performance Liquid Chromatography (UPLC) unit with a BEH C18 column (2.1mm×50mm, 1.7µm). The mobile phase was composed of acetonitrile and 0.1% formic acid in water. No endogenous interfering compounds was discovered at retention time of brigatinib (0.56min) and imatinib (IS, 1.41min). MS/MS detection was performed in positive mode. And the MRM transitions were m/z 584.09→484.08 and m/z 494.3→394.2 for brigatinib and IS, respectively. This method was assessed to be stable, specificity, and no matrix effect in three concentrations (0.004, 0.4, 4µg/mL). The intra-day and inter-day precisions were less than 11.09% and 6.43%. And intra-day and inter-day accuracies were ranged from -3.88% to 5.44%. The recovery of brigatinib was from 85.26% to 96.05%. Additionally, the method had a good linearity in the range of 0.002-5µg/mL. The presented method was effectively implemented to determine the concentration of brigatinib in rat plasma.

Functional characterization of wild-type and 24 CYP2D6 allelic variants on gefitinib metabolism in vitro.

BACKGROUND: Cytochrome P450 2D6 (CYP2D6), a member of the CYP450 enzyme super family, is a polymorphic enzyme that metabolizes ~25% of therapeutic drugs. CYP2D6 exhibits significant genetic polymorphisms which might cause adverse effects and therapeutic failures of some drugs. OBJECTIVE: The purpose of this study was to evaluate the catalytic activities of 22 novel CYP2D6 alleles (CYP2D6*87, *88, *89, *90, *91, *92, *93, *94, *95, *96, *97, *98, R25Q, F164L, E215K, F219S, V327M, D336N, V342M, R344Q, R440C, R497C) on the metabolism of gefitinib in vitro. METHODS AND RESULTS: CYP2D6 variants were incubated with 1-100 µM gefitinib for 60 min at 37°C and the reaction was terminated by cooling to -80°C immediately. Gefitinib and its metabolite O-desmethyl gefitinib were analyzed by an ultra-performance liquid chromatography-tandem mass spectrometry system. Compared to CYP2D6.1, most CYP2D6 variants exhibited significantly decreased relative clearance values (from 3.11% to 79.35%), whereas CYP2D6.92 and CYP2D6.96 displayed no detectable enzyme activity. Only CYP2D6.94 exhibited a markedly increased intrinsic clearance value, and eight variants (CYP2D6.88, CYP2D6.89, CYP2D6.91, CYP2D6.97, V342M, R344Q, F219S, and F164L) showed no significant difference. In addition, 23 CYP2D6 allelic isoforms exhibited substrate inhibition trend toward gefitinib. CONCLUSION: As the first study of all the aforementioned alleles for gefitinib metabolism, these comprehensive data may help in the clinical assessment of the metabolism of gefitinib, and may also offer a reference for personalized treatment with gefitinib in clinical settings.