Development and validation of a sensitive LC–MS/MS method for simultaneous determination of eight tyrosine kinase inhibitors and its application in mice pharmacokinetic studies

Pretreatment and analysis techniques development of TKIs in biological samples for pharmacokinetic studies and therapeutic drug monitoring

Tyrosine kinase inhibitors (TKIs) have emerged as the first-line small molecule drugs in many cancer therapies, exerting their effects by impeding aberrant cell growth and proliferation through the modulation of tyrosine kinase-mediated signaling pathways. However, there exists a substantial inter-individual variability in the concentrations of certain TKIs and their metabolites, which may render patients with compromised immune function susceptible to diverse infections despite receiving theoretically efficacious anticancer treatments, alongside other potential side effects or adverse reactions. Therefore, an urgent need exists for an up-to-date review concerning the biological matrices relevant to bioanalysis and the sampling methods, clinical pharmacokinetics, and therapeutic drug monitoring of different TKIs. This paper provides a comprehensive overview of the advancements in pretreatment methods, such as protein precipitation (PPT), liquid-liquid extraction (LLE), solid-phase extraction (SPE), micro-SPE (μ-SPE), magnetic SPE (MSPE), and vortex-assisted dispersive SPE (VA-DSPE) achieved since 2017. It also highlights the latest analysis techniques such as newly developed high performance liquid chromatography (HPLC) and high-resolution mass spectrometry (HRMS) methods, capillary electrophoresis (CE), gas chromatography (GC), supercritical fluid chromatography (SFC) procedures, surface plasmon resonance (SPR) assays as well as novel nanoprobes-based biosensing techniques. In addition, a comparison is made between the advantages and disadvantages of different approaches while presenting critical challenges and prospects in pharmacokinetic studies and therapeutic drug monitoring.

Simultaneous quantification of donafenib, sorafenib, and their N-oxide metabolites in rat plasma using a HPLC-MS/MS method

Donafenib and sorafenib are small molecule chemotherapy drugs for the management of hepatocellular carcinoma, with donafenib being a deuterated derivative of sorafenib. To date, a high liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method that quantify donafenib, sorafenib, and their main metabolites has not yet been developed. The objective of this study was to establish a HPLC-MS/MS method for the simultaneous detection of donafenib, donafenib-N-oxide, sorafenib, and sorafenib-N-oxide and for the pharmacokinetic studies in rat. The extraction of all analytes was achieved by simple protein precipitation utilizing acetonitrile. The Waters XBridge C18 column (2.1 × 100 mm, 3.5 µm) was selected, and the analytes could be efficiently separated and quantitated during a 2.8 min gradient elution procedure. The method was linear within the predefined quantification ranges and provided acceptable precision (%CV < 9.4%), reproducible extraction recovery (99.4%-111.5%), and low matrix effect (88.1%-98.6%). The hemolysis effect did not interfere with the quantification of all analytes, and similar results were obtained by changing the anticoagulant K2-EDTA to heparin or sodium citrate. Plasma pharmacokinetics revealed that the values of t1/2, Cmax, and AUC0-t of donafenib were 1.4-, 6.2-, and 3.1-fold higher than those of sorafenib, respectively. In conclusion, the proposed bioassay was successfully applied to pharmacokinetic studies in rat after administration of donafenib and sorafenib. Our work not only improves the bioanalytical method for determining the plasma concentrations of donafenib, sorafenib, and their N-oxide metabolites, but also provides a scientific reference for clinical pharmacokinetic studies.

Detection of Axitinib Using Multiwalled Carbon Nanotube-Fe2O3/Chitosan Nanocomposite-Based Electrochemical Sensor and Modeling with Density Functional Theory

In this study, axitinib (AXI), a potent and selective inhibitor of vascular endothelial growth factor receptor (VEGFR) tyrosine kinase and used as a second-generation targeted drug, was investigated electrochemically under optimized conditions using multiwalled carbon nanotubes/iron(III) oxide nanoparticle-chitosan nanocomposite (MWCNT/Fe₂O₃@chitosan NC) modified on the glassy carbon electrode (GCE) surface. Characterization of the modified electrode was performed using scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). The adsorptive stripping differential pulse voltammetric (AdSDPV) technique was used for the sensitive, rapid, and precise detection of AXI. The current peak obtained with the MWCNT/Fe₂O₃@chitosan NC modified electrode was 23 times higher compared to the bare electrode. The developed modified electrode showed excellent electrocatalytic activity in AXI oxidation. Under optimized conditions, the effect of supporting electrolyte and pH was investigated, and 0.1 M H₂SO₄ was chosen as the electrolyte with the highest peak current for the target analyte. In the concentration range of MWCNT/Fe₂O₃@chitosan NC/GCE, 6 × 10^-9 and 1 × 10^-6 M, the limit of detection (LOD) and limit of quantification (LOQ) values were calculated to be 0.904 and 0.0301 pM, respectively. Tablet and serum samples were used for the applicability of the developed sensor, relative standard deviation (RSD) values for all samples were below 2%, and the recovery results were 99.23 and 101.84%, respectively. The MWCNT/Fe₂O₃@chitosan NC/GCE designed to determine AXI demonstrated the applicability, selectivity, precision, and accuracy of the sensor. The mechanism of electron transfer from the modified GCE surface to the analyte solution is studied via modeling the modified GCE surface by the density functional theory (DFT) method at B3LYP/6-311+g(d,p) and M062X/6-31g(d,p) levels. We observed that the iron oxide nanoparticles play an important role in channeling electron flow from the analyte solution to the MWCNT-coated GCE electrode surface. Adsorption of the nanocomposite material onto the GCE surface occurs via strong electrostatic interactions, including ionic and hydrogen bond formations. During the adsorption-controlled oxidation process of the axitinib, the electrons are transferred via the highest occupied molecular orbital (HOMO) localized on the iron oxide moiety to the lowest unoccupied molecular orbital (LUMO) of the MWCNT/GCE surface.

Development of UPLC-MS/MS Method to Study the Pharmacokinetic Interaction between Sorafenib and Dapagliflozin in Rats

Sorafenib (SOR), an inhibitor of multiple kinases, is a classic targeted drug for advanced hepatocellular carcinoma (HCC) which often coexists with type 2 diabetes mellitus (T2DM). Dapagliflozin (DAPA), a sodium–glucose cotransporter-2 inhibitor (SGLT2i), is widely used in patients with T2DM. Notably, co-administration of SOR with DAPA is common in clinical settings. Uridine diphosphate-glucuronosyltransferase family 1 member A9 (UGT1A9) is involved in the metabolism of SOR and dapagliflozin (DAPA), and SOR is the inhibitor of UGT1A1 and UGT1A9 (in vitro). Therefore, changes in UGT1A9 activity caused by SOR may lead to pharmacokinetic interactions between the two drugs. The objective of the current study was to develop an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the simultaneous determination of SOR and DAPA in plasma and to evaluate the effect of the co-administration of SOR and DAPA on their individual pharmacokinetic properties and the mechanism involved. The rats were divided into four groups: SOR (100 mg/kg) alone and co-administered with DAPA (1 mg/kg) for seven days, and DAPA (1 mg/kg) alone and co-administered with SOR (100 mg/kg) for seven days. Liquid–liquid extraction (LLE) was performed for plasma sample preparation, and the chromatographic separation was conducted on Waters XSelect HSS T3 column with a gradient elution of 0.1% formic acid and 5 mM ammonium acetate (Phase A) and acetonitrile (Phase B). The levels of Ugt1a7 messenger RNA (mRNA) were determined in rat liver and intestine using quantitative real-time polymerase chain reaction (qRT-PCR). The method was successfully applied to the study of pharmacokinetic interactions. DAPA caused a significant decrease in the maximum plasma concentrations (Cmax) and the area under the plasma concentration–time curves (AUC0–t) of SOR by 41.6% and 50.5%, respectively, while the apparent volume of distribution (Vz/F) and apparent clearance (CLz/F) significantly increased 2.85- and 1.98-fold, respectively. When co-administering DAPA with SOR, the AUC0–t and the elimination half-life (t1/2Z) of DAPA significantly increased 1.66- and 1.80-fold, respectively, whereas the CLz/F significantly decreased by 40%. Results from qRT-PCR showed that, compared with control, seven days of SOR pretreatment decreased Ugt1a7 expression in both liver and intestine tissue. In contrast, seven days of DAPA pretreatment decreased Ugt1a7 expression only in liver tissue. Therefore, pharmacokinetic interactions exist between long-term use of SOR with DAPA, and UGT1A9 may be the targets mediating the interaction. Active surveillance for the treatment outcomes and adverse reactions are required.

Rapid Determination of 9 Tyrosine Kinase Inhibitors for the Treatment of Hepatocellular Carcinoma in Human Plasma by QuEChERS-UPLC-MS/MS

A reliable and rapid method employing QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) pretreatment coupled with ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) was successfully developed and validated for the analysis of nine tyrosine kinase inhibitors (TKIs) in human plasma. Biological samples were extracted with acetonitrile and salted out with 350 mg of anhydrous magnesium sulfate (MgSO₄), followed by purification with 40 mg of ethyl enediamine-N-propylsilane (PSA) adsorbents. All analytes and internal standards (IS) were separated on the Hypersil GOLD VANQUISH C18 (2.1 mm × 100 mm, 1.9 μM) column using the mobile phases composed of acetonitrile (phase A) and 0.1% formic acid in water (phase B) for 8.0 min. Detection was performed by selection reaction monitoring (SRM) in the positive ion electrospray mode. Lenvatinib, sorafenib, cabozantinib, apatinib, gefitinib, regorafenib, and anlotinib rendered good linearity over the range of 0.1–10 ng/ml, and 1–100 ng/ml for tivantinib and galunisertib. All linear correlation coefficients for all standard curves were ≥ 0.9966. The limits of detection (LOD) and the limits of quantitation (LOQ) ranged from 0.003 to 0.11 ng/ml and 0.01–0.37 ng/ml, respectively. The method was deemed satisfactory with an accuracy of -7.34–6.64%, selectivity, matrix effect (ME) of 90.48–107.77%, recovery, and stability. The proposed method is simple, efficient, reliable, and applicable for the detection of TKIs in human plasma samples as well as for providing a reference for the clinical adjustment of drug administration regimen by monitoring the drug concentrations in the plasma of patients.

Determination of zilpaterol in a residue depletion study using LC-MS/MS in cattle plasma, muscle, liver and kidney

Zilpaterol is a β-agonist compound which promotes fat loss and muscle gain in cattle, providing economic benefits. However, zilpaterol residues in the animal might introduce a significant risk to humans after consumption. In the present manuscript, a highly specific, sensitive method using Selected Reaction Monitoring (SRM) in positive electrospray ionization (ESI +) mode by liquid chromatography coupled to triple quadrupole mass spectrometry (LC-MS/MS) for plasma, muscle, liver and kidney is presented. For method development, composition of the aqueous mobile phase, precipitation agent, and solid phase extraction (SPE) conditions were optimized. The method was fully validated showing a good linearity and recovery average greater than or equal to 97 % for all matrices. The method was applied to residue depletion studies in cattle after withdrawal of zilpaterol supplementation at 3, 4, 5 and 6 days showing that tissues can be consumed by humans after 4th day of zilpaterol withdrawal.

Lapatinib: A comprehensive profile

Lapatinib is an anticancer used for treatment of the patients with advanced metastatic breast cancer in conjunction with the chemotherapy drug capecitabine or with letrozole for the treatment of postmenopausal women with hormone receptor-positive metastatic breast cancer. This comprehensive profile of Lapatinib gives more detailed information about the description, formulae, Elemental Analysis, Uses and application. Furthermore, methods and schemes are outlined for the preparation of the drug substance. The physical properties of the medication include constant of ionization, solubility, X-ray powder diffraction pattern, differential scanning calorimetry, thermal conduct and spectroscopic studies are investigated. The methods employed in bulk medicines and/or in pharmaceutical formulations to analyze the drug substance include spectrophotometric, electrochemical and the chromatographic methods are indicated. Other studies on this drug substance include drug stability, pharmaceutical applications, mechanism of action, pharmacodynamics, and a dosing information are also reviewed.

Simultaneous and Rapid Determination of Six Tyrosine Kinase Inhibitors in Patients with Non-Small Cell Lung Cancer Using HPLC-MS/MS

Objective

To develop a new method for quantitatively analyzing six tyrosine kinase inhibitors (gefitinib, erlotinib, icotinib, afatinib, osimertinib, and crizotinib) used in the treatment of non-small cell lung cancer (NSCLC) by liquid chromatography-tandem mass spectrometry (LC-MS/MS).

Methods

The analytes were detected in the selected reaction monitoring mode on a triple quadrupole mass spectrometer with the positive ionization mode. Carbamazepine was utilized as the internal standard. The pretreatment of the plasma sample was completed based on protein precipitation with acetonitrile, and the analytes were separated on an Agilent Zorbax SB-C18 reversed-phase column (2.1 mm × 100 mm, 3.5 μm, Agilent, USA) using gradient elution. The mobile phase consisted of 0.1% formic acid in water (phase A) and 0.1% formic acid in acetonitrile (phase B). The flow rate was 0.3 mL/min, and the injection volume was 5 μL. The column temperature was set and maintained at 35°C.

Results

The calibration curves were linear over the range from 5.0 to 1000.0 ng/mL for gefitinib, crizotinib, and osimertinib; from 50.0 to 4000.0 ng/mL for icotinib and erlotinib; and from 5.0 to 400.0 ng/mL for afatinib. Linear correlation coefficients were >0.990 for all regression curves. The intra- and interday accuracy and precision of the method were within ±15.0% and not more than 15.0%, respectively. The mean recovery of all the analytes ranged from 70.18% to 110.76%, the matrix effect was from 88.85% to 127.58%, and stability was within ±15.0%.

Conclusion

This newly developed method was sensitive, simple, and robust and could be used in therapeutic drug monitoring of six tyrosine kinase inhibitors in NSCLC patients.

Simultaneous and rapid determination of 12 tyrosine kinase inhibitors by LC-MS/MS in human plasma: Application to therapeutic drug monitoring in patients with non-small cell lung cancer

In recent years, more than 50 tyrosine kinase inhibitors (TKIs) was indicated against numerous cancers, especially outstanding advantages in the treatment of non-small cell lung cancer (NSCLC), and several studies have shown that therapeutic drug monitoring (TDM) of TKIs can improve treatment efficacy and safety. The present study aimed to develop and validate a LC-MS/MS method for the TDM of 12 TKIs (gefitinib, erlotinib, afatinib, dacomitinib, icotinib, osimertinib, crizotinib, ceritinib, alectinib, dabrafenib, trametinib, anlotinib) in patients with NSCLC. The analytes of interest and internal standard were extracted from human plasma. Salting-out assisted liquid-liquid extraction (SALLE) with 5 M ammonium acetate solution was optimized for method validation and compared to simple protein precipitation (PPT). Chromatographic separation was conducted on Waters X bridge C18 column (100 × 4.6 mm, 3.5 μm) using a gradient elution of acetonitrile/5mM ammonium acetate in pure water with 0.1% (v/v) formic acid at 40 °C within 6 min. The total flow was maintained at 1 mL/min, 30% of the post column flow was split into the mass spectrometer and the rest to waste via a 3-way tee. The mass analysis was performed by positive ion electrospray ionization (ESI) in multiple-reaction monitoring (MRM) mode. The assay was validated based on the guidelines on bioanalytical methods by FDA. This quantification method was proved to be satisfactory in selectivity, accuracy, precision, linearity (r² > 0.995), recovery, matrix effect and stability and the accuracy was further assessed in plasma with a degree of hemolysis of 4%. The described method to simultaneously quantify the 12 selected anticancer drugs in human plasma was successfully validated and applied to routine TDM of gefitinib, erlotinib, icotinib, osimertinib, crizotinib and anlotinib in cancer patients. TKIs plasma monitoring helps to individualize dose adjustment and manage adverse effects in NSCLC patients.

Therapeutic Drug Monitoring of Sunitinib in Gastrointestinal Stromal Tumors and Metastatic Renal Cell Carcinoma in Adults-A Review

BACKGROUND

Sunitinib is an inhibitor of multiple receptor tyrosine kinases and is a standard-of-care treatment for advanced and metastatic renal cell carcinoma and a second-line treatment in locally advanced inoperable and metastatic gastrointestinal stromal tumors. A fixed dose of the drug, however, does not produce a uniform therapeutic outcome in all patients, and many face adverse effects and/or toxicity. One of the possible causes of the interindividual variability in the efficacy and toxicity response is the highly variable systemic exposure to sunitinib and its active metabolite. This review aims to summarize all available clinical evidence of the treatment of adult patients using sunitinib in approved indications, addressing the necessity to introduce proper and robust therapeutic drug monitoring (TDM) of sunitinib and its major metabolite, N-desethylsunitinib.

METHODS

The authors performed a systematic search of the available scientific literature using the PubMed online database. The search terms were "sunitinib" AND "therapeutic drug monitoring" OR "TDM" OR "plasma levels" OR "concentration" OR "exposure." The search yielded 520 journal articles. In total, 447 publications were excluded because they lacked sufficient relevance to the reviewed topic. The remaining 73 articles were, together with currently valid guidelines, thoroughly reviewed.

RESULTS

There is sufficient evidence confirming the concentration-efficacy and concentration-toxicity relationship in the indications of gastrointestinal stromal tumors and metastatic renal clear-cell carcinoma. For optimal therapeutic response, total (sunitinib + N-desethylsunitinib) trough levels of 50-100 ng/mL serve as a reasonable target therapeutic range. To avoid toxicity, the total trough levels should not exceed 100 ng/mL.

CONCLUSIONS

According to the current evidence presented in this review, a TDM-guided dose modification of sunitinib in selected groups of patients could provide a better treatment outcome while simultaneously preventing sunitinib toxicity.

FDA- and EMA-Approved Tyrosine Kinase Inhibitors in Advanced EGFR-Mutated Non-Small Cell Lung Cancer: Safety, Tolerability, Plasma Concentration Monitoring, and Management

Non-small-cell lung cancer (NSCLC) is the most common form of primary lung cancer. The discovery of several oncogenic driver mutations in patients with NSCLC has allowed the development of personalized treatments based on these specific molecular alterations, in particular in the tyrosine kinase (TK) domain of the epidermal growth factor receptor (EGFR) gene. Gefitinib, erlotinib, afatinib, and osimertinib are TK inhibitors (TKIs) that specifically target EGFR and are currently approved by the Food and Drug Administration (FDA) and the European Medicines Agency (EMA) as first line treatment for sensitive EGFR-mutant patients. However, these four drugs are associated with severe adverse events (AEs) that can significantly impact patient health-related quality of life and patient monitoring. EGFR-TKIs are commonly used together with other types of medication that can substantially interact. Here, we review approaches used for the management of TKI-AEs in patients with advanced NSCLC to promote the benefits of treatments and minimize the risk of TKI treatment discontinuation. We also consider potential TKI–drug interactions and discuss the usefulness of plasma concentration monitoring TKIs based on chromatographic and mass spectrometry approaches to guide clinical decision-making. Adjusting the most appropriate therapeutic strategies and drug doses may improve the performance therapy and prognosis of patients with advanced EGFR-mutated NSCLC.

LC-ESI-QTOF-MS analysis utilizing gas-phase fragmentation reactions subjected to ESI-IS-CID and ESI-CID-MS/MS conditions to study the degradation behaviour of sorafenib tosylate: NMR and in vitro cytotoxicity and apoptosis detection studies of hydrolytic degradation products

The present study was to investigate the degradation profile of sorafenib tosylate (SORA), a potent oral multi-kinase inhibitor under various stress conditions as per ICH (Q1A (R2)) guidelines. Separation of SORA and its degradation products (DP-1-DP-5) was achieved on Acquity UPLC BEH C18 (100 mm × 2.1 mm × 1.7 μm) column using a gradient elution of 0.1% formic acid and acetonitrile at a flow rate of 0.3 mL/min within 12 min. High resolution quadruple time-of-flight mass spectrometer (Q-TOF/MS) was utilized for characterization of all DPs. In ESI/CID-MS/MS experiments, the protonated DP-1 and DP-2 exhibited few interesting product ions which provide a compelling evidence for the compounds to undergo gas phase rearrangement reaction justified by its mechanistic explanation in support with density functional theory (DFT). In-source collision-induced dissociation (IS-CID) fragmentation using ESI/APCI-MS analysis exhibited the formation of N-deoxygenated product ion peak corresponds to pyridine N-oxide moiety as in DP-5. Further, major hydrolytic DPs (DP-2 and DP-3) were isolated on preparative HPLC and structural elucidation was done using ID NMR (¹H, ¹³C and DEPT-135) experiments. In vitro cytotoxicity study for SORA and its isolated DPs were assessed by observing morphological changes in HepG2 cell lines under phase-contrast microscopy and MTT assay. Taken together, it was known that DP-2 and DP-3 were less potent with a cell viability of more than 90% and IC₅₀ >50 μM in comparison with SORA (IC₅₀ = 2.99 ± 0.35 μM). The developed method was validated in terms of specificity, limit of detection, limit of quantification, linearity, accuracy, precision and robustness.

Sorafenib

Sorafenib (BAY-43-9006), marketed by Bayer as Nexavar® (USA), is anticancer drug approved by US-FDA for the treatment of unresectable hepatocellular carcinoma and advanced renal cell carcinoma. Sorafenib inhibited tumor growth and angiogenesis through targeting both the RAF/MEK/ERK pathway and receptor tyrosine kinases. This study presents a comprehensive profile of sorafenib, including detailed nomenclature, formula, elemental analysis, methods of preparation, physico-chemical characteristics, and methods of analysis (including spectroscopic, electrochemical, and chromatographic methods of analysis). Spectroscopic and spectrometric analyses include UV/vis spectroscopy, vibrational spectroscopy, nuclear magnetic resonance spectrometry ((1)H and (13)C NMR), and mass spectrometry. Chromatographic methods of analyses include thin layer chromatography and high-performance liquid chromatography. Only few stability indicating methods were found for quantification of sorafenib after exposing tablet dosage form to various stress conditions such as hydrolysis, oxidation, thermal stress, photo and UV light. However, none of these described methods were made to separate and quantify the degradation products. Pharmacology studies including pharmacodynamics, mechanism of action, pharmacokinetics and drug-drug interactions were also presented. An appropriate table and figures were attached to each of the above mentioned sections along with total of 55 references.

A new apatinib microcrystal formulation enhances the effect of radiofrequency ablation treatment on hepatocellular carcinoma

Introduction

Radiofrequency ablation (RFA) is the foremost treatment option for advanced hepatocellular carcinoma (HCC), however, rapid and aggressive recurrence of HCC often occurs after RFA due to epithelial–mesenchymal transition process. Although combination of RFA with sorafenib, a molecular targeted agent, could attenuate the recurrence of HCC, application of this molecular targeted agent poses a heavy medical burden and oral administration of sorafenib also brings severe side effects.

Materials and methods

In this study, we prepared an apatinib microcrystal formulation (Apa-MS) that sustainably releases apatinib, a novel molecular targeted agent, for advanced HCC treatment. We injected apatinib solution or Apa-MS into subcutaneous HCC tumors.

Results

It was found that Apa-MS exhibited slow apatinib release in vivo and in turn inhibited the epithelial–mesenchymal transition of HCC cells for extended time. Moreover, in rodent HCC model, Apa-MS enhanced the antitumor effect of RFA treatment.

Conclusion

Based on these results, we conclude that Apa-MS, a slow releasing system of apatinib, allows apatinib to remain effective in tumor tissues for a long time and could enhance the antitumor effect of RFA on HCC.

Triclosan treatment decreased the antitumor effect of sorafenib on hepatocellular carcinoma cells

Background

Triclosan is a widely applied antimicrobial agent which affects the endocrine system and homeostasis; it may also promote the cirrhosis and hepatocellular carcinoma (HCC) growth in a mice model. The exact roles of triclosan in regulating human hepatocellular carcinoma development and treatment remain unknown.

Methods

MHCC97-H, a highly aggressive HCC cell line, was treated with indicated concentration of triclosan or sorafenib. The expression of drug-resistance genes was examined by qPCR. The clearance or metabolism of sorafenib was determined by liquid chromatograph-mass spectrometer/mass spectrometer (LC-MS/MS). MTT assay was used to examine the MHCC97-H cell proliferation. Nude mice were used to exam the anti-tumor effect of sorafenib on subcutaneous and intrahepatic growth of MHCC97-H cells.

Results

In the present study, triclosan could induce the expression of drug-resistance genes in MHCC97-H cells (a highly aggressive HCC cell line), accelerate the clearance of sorafenib, and attenuate the anti-proliferation effect of this molecular targeted agent in MHCC97-H cells. Triclosan decreased the antitumor effect of sorafenib on subcutaneous and intrahepatic growth of MHCC97-H in nude mice.

Conclusion

By discovering the fact that triclosan treatment enhances sorafenib resistance in HCC cells, this work suggests exposure of triclosan is detrimental to HCC patients during chemotherapy.

Pregnane X receptor mediates sorafenib resistance in advanced hepatocellular carcinoma

BACKGROUND

Kinase inhibitor sorafenib is the most widely used drug for advanced HCC clinical treatment nowadays. However, sorafenib administration is only effective for a small portion of HCC patients, and the majority develop sorafenib-resistance during treatment. Thus, it is urgent to discover the endogenous mechanism and identify new pharmaceutical targets of sorafenib-resistance.

METHODS

Pregnane X receptor (PXR) was detected by immunohistochemistry and quantitative PCR. GST-pull down and LC-MS/MS was used to detect the interaction of PXR and Sorafenib. To test the properties of HCC tumor growth and metastasis, in vivo tumor explant model, FACS, trans-well assay, cell-survival inhibitory assay and Western blot were performed. In terms of mechanistic study, additional assays such as ChIP and luciferase reporter gene assay were applied.

RESULTS

In the present work, we found high PXR level in clinical specimens is related to the poor prognosis of Sorafenib treated patients. By the mechanistic studies, we show that sorafenib binds to PXR and activates PXR pathway, and by which HCC cells develop sorafenib-resistance via activating. Moreover, PXR overexpression helps HCC cells to persist to sorafenib treatment.

CONCLUSION

This study reports the endogenous sorafenib-resistance mechanism in HCC cells, which offers an opportunity to design new therapeutic approaches for HCC treatment.

GENERAL SIGNIFICANCE

PXR mediates sorafenib-resistance in HCC cells and targeting PXR can be a useful approach to facilitate HCC treatment.