Metabolomics and miRNA profiling reveals feature of gallbladder cancer-derived biliary extracellular vesicles.

BACKGROUND: Although there are several studies in the development of various human cancers, the role of exosomes is poorly understood in the progression of gallbladder cancer. This study aims to characterize the metabolic changes occurring in exosomes obtained from patients with gallbladder cancer compared with those from other gallbladder disease groups. METHODS: Biliary exosomes were isolated from healthy donors (n = 3) and from patients with gallbladder cancer (n = 3), gallbladder polyps (n = 4), or cholecystitis (n = 3) using a validated exosome isolation kit. Afterward, we performed miRNA profiling and untargeted metabolomic analysis of the exosomes. The results were validated by integrating the results of the miRNA and metabolomic analyses. RESULTS: The gallbladder cancer group exhibited a significant reduction in the levels of multiple unsaturated phosphatidylethanolamines and phosphatidylcholines compared to the normal group, which resulted in the loss of exosome membrane integrity. Additionally, the gallbladder cancer group demonstrated significant overexpression of miR-181c and palmitic acid, and decreased levels of conjugated deoxycholic acid, all of which are strongly associated with the activation of the PI3K/AKT pathway. CONCLUSIONS: Our findings demonstrate that the contents of exosomes are disease-specific, particularly in gallbladder cancer, and that altered metabolites convey critical information regarding their phenotype. We believe that our metabolomic and miRNA profiling results may provide important insights into the development of gallbladder cancer.

Development of simultaneous quantitative analytical method for metabolites of hexosamine biosynthesis pathway in lung cancer cells using ultra-high-performance liquid chromatography-tandem mass spectrometry.

The hexosamine biosynthesis pathway (HBP) is a glucose metabolism pathway that produces uridine diphosphate N-acetyl glucosamine (UDP-GlcNAc). Substantial changes in HBP, including elevated HBP flux and UDP-GlcNAc levels, are associated with cancer pathogenesis. Particularly, cancer cells expressing oncogenic Kirsten rat sarcoma virus (KRAS) are highly dependent on HBP for growth and survival. To differentiate between HBP metabolites in KRAS wild-type (WT) and mutant (MT) lung cancer cells, a simultaneous quantitative method for analyzing seven HPB metabolites was developed using ultra-high-performance liquid chromatography-tandem mass spectrometry. A simple method without complicated preparation steps, such as derivatization or isotope labeling, was optimized for the simultaneous analysis of highly hydrophilic HBP metabolites, and the developed method was successfully verified. The intra- and inter-day coefficients of variation were less than 15% for all HBP metabolites, and the recovery was 89.67-114.5%. All results of the validation list were in accordance with ICM M10 guidelines. Through this method, HBP metabolites in lung cancer cells were accurately quantified, and it was confirmed that all HBP metabolites were upregulated in KRAS MT cells compared with KRAS WT lung cancer cells. We expect that this will be a useful tool for metabolic research on cancer and for the development of new drugs for cancer treatment.

Identification of integrative hepatotoxicity induced by lysosomal phospholipase A2 inhibition of cationic amphiphilic drugs via metabolomics.

Drug-induced liver injury (DILI) is a condition caused by drugs that leads to abnormal hepatic function. Hepatotoxicity caused by DILI has been shown to be due to cellular stress, mitochondrial dysfunction, cell necrosis and apoptosis and many types of hepatotoxicity, such as phospholipidosis, steatosis and hepatitis, commonly share intracellular molecular mechanisms. Metabolomics can be useful for mechanism-based toxicity evaluations and has been recently utilized as a scientific technique that can effectively predict the risk factors for chemical substances. To evaluate the key events in hepatotoxicity associated with lysosomal phospholipase A2 (LPLA2) inhibition by cationic amphiphilic drugs (CADs), LPLA2 inhibition assays and phospholipid accumulation assays were performed in HepG2 cells. Additionally, to suggest the integrative molecular mechanisms of hepatotoxicity by CADs, we profiled intracellular metabolites. Cell-based metabolomics was performed using an UPLC-Orbitrap-MS instrument equipped with heated electrospray ionization in positive and negative ion modes. As a result, CADs such as amiodarone, fluoxetine, chlorpromazine and tamoxifen significantly inhibited LPLA2 and accumulated phospholipids. In metabolomics, a total of 17 significant metabolites were identified, and the changed metabolite types were as follows: nucleotide sugars, conjugated bile acids, branched-chain amino acids, polyamine biosynthesis, and long-chain fatty acid and glycerophospholipid metabolism. From these data, it was suggested that the integrative mechanism of DILI could be verified and that a toxicological approach is possible using metabolomics.

Intratracheal exposure to polyhexamethylene guanidine phosphate disrupts coordinate regulation of FXR-SHP-mediated cholesterol and bile acid homeostasis in mouse liver.

A public health crisis in the form of a significant incidence of fatal pulmonary disease caused by repeated use of humidifier disinfectants containing polyhexamethylene guanidine phosphate (PHMG) recently arose in Korea. Although the mechanisms of pulmonary fibrosis following respiratory exposure to PHMG are well described, distant-organ effect has not been reported. In this study, we investigated whether intratracheal administration of PHMG affects liver pathophysiology and metabolism. Our PHMG mouse model showed a significant decrease in liver cholesterol level. An mRNA-seq analysis of liver samples revealed an alteration in the gene expression associated with cholesterol biosynthesis and metabolism to bile acids. The expression of genes involved in cholesterol synthesis was decreased in a real-time PCR analysis. To our surprise, we found that the coordinate regulation of cholesterol and bile acid homeostasis was completely disrupted. Despite the decreased cholesterol synthesis and low bile acid levels, the farnesoid X receptor/small heterodimer partner pathway, which controls negative feedback of bile acid synthesis, was activated in PHMG mice. As a consequence, gene expression of Cyp7a1 and Cyp7b1, the rate-limiting enzymes of the classical and alternative pathways of bile acid synthesis, was significantly downregulated. Notably, the changes in gene expression were corroborated by the hepatic concentrations of the bile acids. These results suggest that respiratory exposure to PHMG could cause cholestatic liver injury by disrupting the physiological regulation of hepatic cholesterol and bile acid homeostasis.

Short-term changes in the serum metabolome after laparoscopic sleeve gastrectomy and Roux-en-Y gastric bypass.

INTRODUCTION: Bariatric surgery is known to be the most effective treatment for weight loss in obese patients and for the rapid remission of obesity-related comorbidities. These short-term improvements result from not only limited digestion or absorption but also dynamic changes in metabolism throughout the whole body. However, short-term metabolism studies associated with bariatric surgery in Asian individuals have not been reported. OBJECTIVES: The aim of this study was to investigate the short-term metabolome changes in the serum promoted by laparoscopic sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) and to determine the underlying mechanisms that affect obesity-related comorbidities. METHODS: Serum samples were collected from Korean patients who underwent RYGB or SG before and 4 weeks after the surgery. Metabolomic and lipidomic profiling was performed using UPLC-Orbitrap-MS, and data were analyzed using statistical analysis. RESULTS: Metabolites mainly related to amino acids, lipids (fatty acids, glycerophospholipids, sphingolipids, glycerolipids) and bile acids changed after surgery, and these changes were associated with the lowering of risk factors for obesity-related diseases such as nonalcoholic fatty liver disease (NAFLD), type 2 diabetes (T2D) and atherosclerosis. Interestingly, the number of significantly altered metabolites related to the lipid metabolism were greater in SG than in RYGB. Furthermore, the metabolites related to amino acid metabolism were significantly changed only after SG, whereas bile acid changed significantly only following RYGB. CONCLUSION: These differences could result from anatomical differences between the two surgeries and could be related to the gut microbiota. This study provides crucial information to expand the knowledge of the common but different molecular mechanisms involved in obesity and obesity-related comorbidities affected by each bariatric procedure.

Comparative metabolomics and lipidomics study to evaluate the metabolic differences between first- and second-generation mammalian or mechanistic target of rapamycin inhibitors.

Mammalian or mechanistic target of rapamycin (mTOR) drives its fundamental cellular functions through two distinct catalytic subunits, mTORC1 and mTORC2, and is frequently dysregulated in most cancers. To treat cancers, developed mTOR inhibitors have been classified into first and second generations based on their ability to inhibit single (first-generation) and dual (second-generation) mTOR subunits. However, the underlying metabolic differences due to the effects of first- and second-generation mTOR inhibitors have not been clearly evaluated. In this study, rapamycin (sirolimus) and AZD8055 and PP242 were selected as first- and second-generation mTOR inhibitors, respectively, to evaluate the metabolic differences due to these two generations of mTOR inhibitors after a single oral dose using untargeted metabolomics and lipidomics approaches. The metabolic differences at each time point were compared using multivariate analysis. The multivariate and data analyses showed that metabolic disparity was more prominent within 8 h after drug administration and a broad class of metabolites were affected by the administration of both generations of mTOR inhibitors. Among the metabolite classes, changes in the pattern of fatty acids and glycerophospholipids were opposite, specifically at 4 and 8 h between the two generations of mTOR inhibitors. We speculate that the inhibition of the mTORC2 subunit by the second-generation mTOR inhibitor may have resulted in a distinct metabolic pattern between the first- and second-generation inhibitors. Finally, the findings of this study could assist in a more detailed understanding of the key metabolic differences caused by first- and second-generation mTOR inhibitors.

USP14 Regulates Cancer Cell Growth in a Fatty Acid Synthase-Independent Manner.

Fatty acid synthase (FASN) plays an important role in cancer development, providing excess lipid sources for cancer growth by participating in de novo lipogenesis. Although several inhibitors of FASN have been developed, there are many limitations to using FASN inhibitors alone as cancer therapeutics. We therefore attempted to effectively inhibit cancer cell growth by using a FASN inhibitor in combination with an inhibitor of a deubiquitinating enzyme USP14, which is known to maintain FASN protein levels in hepatocytes. However, when FASN and USP14 were inhibited together, there were no synergistic effects on cancer cell death compared to inhibition of FASN alone. Surprisingly, USP14 rather reduced the protein levels and activity of FASN in cancer cells, although it slightly inhibited the ubiquitination of FASN. Indeed, treatment of an USP14 inhibitor IU1 did not significantly affect FASN levels in cancer cells. Furthermore, from an analysis of metabolites involved in lipid metabolism, metabolite changes in IU1-treated cells were significantly different from those in cells treated with a FASN inhibitor, Fasnall. These results suggest that FASN may not be a direct substrate of USP14 in the cancer cells. Consequently, we demonstrate that USP14 regulates proliferation of the cancer cells in a fatty acid synthase-independent manner, and targeting USP14 in combination with FASN may not be a viable method for effective cancer treatment.

Identification of interactions between multiple components in Socheongryong-tang using a plant profiling approach.

Traditional herbal medicine consists of multiple components. There are interactions among the components, which affect both potency and toxicity. The preparation of herbal medicines can be a cause of interactions between multicomponents in herbs. To demonstrate the differences in multiherb interactions based on the preparation methods, the changes in the active components in the different preparations of Socheongryong-tang (SCRT) were evaluated using metabolomics profiling. We performed multicomponent profiling of the decoction of SCRT (SCRTD) and individual herb mixture (SCRTM) using ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS). Active compounds from SCRTD and SCRTM were identified using multivariate analysis, and the activities between the two groups were compared. We also evaluated the anti-inflammatory effect of SCRT through investigating the protein expression of iNOS and COX-2 in lipopolysaccharide-induced macrophage RAW 264.7 cells in both groups. From the multivariate analysis, 53 active compounds that have different intensities between SCRTD and SCRTM were identified. The intensities of those components, such as ephedrines, glycyrrhizic acid, 6-gingerol and (2E,4E,8Z,10E)-N-isobutyl-2,4,8,10-dodecatetraenamide, which is newly identified in Asiasarum heterotropoides, were mostly higher in SCRTD than in SCRTM, which was related to the anti-inflammatory effect. From the iNOS inhibition test, it was found that SCRTD had a stronger anti-inflammatory effect than SCRTM. It was demonstrated that multicomponent interactions can be changed by the preparation method, and finally the anti-inflammatory effect in SCRT can be affected.

Development of GC-MS based cytochrome P450 assay for the investigation of multi-herb interaction.

As drug interactions with cytochrome P450 enzymes become increasingly important in the field of drug discovery, a high-throughput screening method for analysing the effects of a drug is needed. We have developed a simple and rapid simultaneous analytical method using a cocktail approach for measuring the activities of seven cytochrome P450 enzymes (CYP1A2, CYP2A6, CYP2C9, CYP2C19, CYP2D6, CYP2E1 and CYP3A4). Human liver microsomes were used as a source for the seven cytochrome P450 enzymes, and a gas chromatography-mass spectrometry (GC-MS) was used for analysing their activities. Kinetic studies and inhibition assays of CYP enzymes were performed using known substrates and inhibitors for validating and comparing the reaction rates and time-dependent activities between methods using each substrate versus a method using a cocktail solution. The optimized cocktail method was successfully applied to evaluate the effects of the decoction of Socheongryong-tang (SCRT) on cytochrome P450 enzymes. Our cocktail method provides a simultaneous high-throughput activity assay using GC-MS for the first time. This method is applicable for analysing the drug interactions of various plant-derived mixtures.

Development of simultaneous analysis of tryptophan metabolites in serum and gastric juice - an investigation towards establishing a biomarker test for gastric cancer diagnosis.

To evaluate changes in tryptophan metabolism and discover diagnostic biomarkers for gastric cancer, a quantitative method was developed for tryptophan and its seven metabolites (indole-3-lactic acid, anthranilic acid, serotonin, nicotinic acid, kynurenic acid, kynurenine and 3-indoxyl sulfate) in both human serum and gastric juice using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Serum and gastric juice were prepared with a simple protein precipitation using aqueous 0.1% formic acid and acetonitrile. As a result, it was found that the kynurenine pathway of tryptophan metabolism was activated in gastric cancer and that the metabolic ratio of kynurenine/tryptophan, which reflects the enzyme activity of indoleamine-2,3-dioxygenase, was associated with the observed metabolic changes. Finally, the investigation of tryptophan metabolites, especially kynurenic acid, in serum and gastric juice might serve as biomarkers for gastric cancer. The findings in this study provide critical information of tryptophan metabolism which can be applied to a serum-based diagnostic test for gastric cancer.

Expression of CYP3A in chronic ethanol-fed mice is mediated by endogenous pregnane X receptor ligands formed by enhanced cholesterol metabolism.

Pregnane X receptor (PXR) is a nuclear receptor that plays a key regulatory role in xenobiotic metabolism in a ligand-dependent manner. Recently, ethanol was reported to be either an inducer or inhibitor of Cytochrome P450 (CYP) 3A expression. According to our recent microarray data, chronic ethanol upregulates the expression of the genes associated with oxidative phase I drug metabolism, phase II conjugation reaction and phase III xenobiotic transport, most of which are known to be regulated by PXR. In this study, we investigated the effects of chronic ethanol on the expression and activity of CYP3A11 in mice and the role of PXR. Ethanol was administrated to male ICR mice by feeding a standard Lieber-DeCarli diet containing 36 % ethanol for 4 weeks. Ethanol significantly increased hepatic mRNA expression of Pxr and Cyp3a11. Treatment of mice with ethanol increased nuclear translocation of PXR. Consistent with the increase in nuclear PXR, ethanol significantly increased the binding of PXR to the Cyp3a11 promoter. Hepatic cholesterol level and bile acid synthesis are increased by ethanol treatment. The level of some cholesterol metabolites, such as 5ß-cholestane-3α,7α,12α-triol, 7α-hydroxy-4-cholestene-3-one and lithocholic acid, that have been identified as potent PXR agonists are increased in the livers of ethanol-treated mice. In summary, chronic ethanol upregulates the expression of Pxr and Cyp3a11 mRNAs and proteins in mice by PXR activation mediated by enhanced cholesterol metabolism and bile acid synthesis. Our data provide some critical information needed to understand the molecular mechanisms of ethanol-induced CYP3A expression.

Highly sensitive immunoassay for the diagnosis of acute myocardial infarction using silica spheres encapsulating a quantum dot layer.

Commercial ELISA kits for substance P (SubP), which are helpful for the clinical diagnosis of acute myocardial infarction, are limited in efficacy because of low sensitivity. A highly sensitive immunoassay was developed using silica spheres encapsulating a quantum dot-layer (SQS) and labeling antibodies, on a Parylene A-modified plate. The high sensitivity was possible by taking advantage of the enhanced photoluminescence of the SQS and dense immobilization of SubP on a Parylene A-modified plate. Glutaraldehyde was used for cross-linking of SQS to the anti-SubP antibody and SubP to the Parylene A coating. The SQS-linked immunosorbent assay (SQSLISA) was optimized and validated. The dynamic range for the assay was 1-10000 pg/mL with a linear correlation factor of 0.9992 when the competitive SQSLISA was employed. The intra- and interday accuracies were 93-100% and 87-122%, respectively. The reproducibility was lower than 11%. The developed method was applied to clinical samples collected from healthy controls (n = 30) and acute myocardial infarction (n = 16) and it displayed a high correlation with the commercial ELISA kit, with a limit of detection that was 30-fold lower. Clinical sample analysis confirmed that SubP is a promising diagnostic marker for acute myocardial infarction. The SQSLISA is expected to be a practical and useful assay tool.

Development of simultaneous quantitative analytical method for three active components of Korean mint (Agastache rugosa (Fisch. & C.A.Mey.) Kuntze) extract in human plasma using ultra-high-performance liquid chromatography-tandem mass spectrometry.

Agastache rugosa contains phenolic compounds and flavonoids, and has been extensively used as a traditional herbal medicine. The major components in Agastache rugosa extract (ARE) are rosmarinic acid, tilianin, and acacetin, for which several analytical techniques have been reported. However, these substances have yet to be simultaneously quantified in human plasma. In this study, we aimed to simultaneously determine the three active components of ARE in human plasma by developing a reliable quantitative analytical method using ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Chromatographic separation of the plasma samples was achieved using an ACQUITY UPLC® BEH C18 column with a gradient mobile phase of water and acetonitrile containing 0.1 % formic acid. Mass spectrometric detection was performed using a triple quadrupole tandem mass spectrometer in negative electrospray ionization (ESI-) and multiple reaction monitoring (MRM) modes. The developed quantitative method was validated for the three active components. All three analytes exhibited a linear response over the ranges of 0.5-50 ng/mL for rosmarinic acid, 0.1-20 ng/mL for acacetin, and 0.5-20 ng/mL for tilianin with a weighting factor of 1/x (where x is the concentration). At three quality control (QC) concentration levels (low, medium, and high), including the lower limit of quantitation (LLOQ), acceptable accuracy (±15 %) was achieved in the intra- and interday validations. The concentration of rosmarinic acid was highest in plasma. Tilianin and acacetin appeared and were eliminated earlier in the plasma than rosmarinic acid. This study provides a successfully validated method that can be used in further clinical applications of Agastache rugosa extracts.

Exploring the Metabolic Effects of a Herbal Remedy of Asarum sieboldii, Platycodon grandiflorum, and Cinnamomum cassia Extracts: Unraveling Its Therapeutic Potential as a Topical Application for Atopic Dermatitis Treatment.

Our previous study demonstrated that our novel herbal remedy, a mixture of Asarum sieboldii, Platycodon grandiflorum, and Cinnamomum Cassia extracts, exhibits a therapeutic effect in 1-chloro-2,4-dinitrobenzene (DNCB)-induced mice by inhibiting the Th-2 inflammatory response upon oral administration. It also ameliorated imbalances in lipid metabolism related to the skin barrier function in keratinocytes, indicating its potential as a topical agent. This study aims to further investigate the therapeutic effects and metabolic mechanisms of its topical application. The anti-atopic effect was evaluated using dermatitis scores, histopathological analysis, and immune cell factors in DNCB-induced mice. Metabolomic profiling of serum and lesional skin was conducted to elucidate the metabolic mechanisms. The topical application significantly reduced dermatitis scores, mast cell infiltration, and serum levels of immunoglobulin E (IgE), IFN-γ, interleukin (IL)-4, IL-17, and thymic stromal lymphopoietin (TSLP), demonstrating its effectiveness in treating atopic dermatitis (AD). Serum metabolomics revealed alterations in fatty acid metabolism related to the pro-inflammatory response. In lesional skin, metabolic markers associated with oxidative stress, immune regulation, and AD symptoms were restored. This study demonstrated its potential as a topical agent in suppressing Th-2 inflammatory responses and improving metabolic abnormalities related to AD symptoms, providing crucial insights for developing natural AD treatments.

Bioavailability of Korean mint (Agastache rugosa) polyphenols in humans and a Caco-2 cell model: a preliminary study exploring the efficacy.

Agastache rugosa, commonly known as Korean mint (KM), is a medicinal plant renowned for its potential health-promoting properties. However, the lack of bioavailability studies has hindered the acquisition of conclusive evidence. In this study, we investigated the bioavailability of six key polyphenols present in KM, including rosmarinic acid (RA), acacetin (AC), and four glycosides of AC. Utilizing UPLC-MS/MS, we analyzed their presence in human plasma and Caco-2 monolayers grown in permeable filter supports. Following single ingestion, we were able to detect RA, AC, and tilianin (TA) in the plasma. Consistent results were obtained for AC and TA but no transport was found for RA in a highly tight Caco-2 cell monolayer, indicating transport through the intercellular space for RA and transepithelial transport for AC and TA. Other AC glucosides with acetyl and/or malonyl groups were rarely found in the plasma. Interestingly, AC glucosides with only an acetyl group appeared at the basolateral side in Caco-2 monolayers, suggesting exclusive hydrolysis of malonyl glucosides in the colon. These findings highlight the high potential of RA, AC, and TA as bioactive compounds that may confer health benefits.

Anti-inflammatory effect and metabolic mechanism of BS012, a mixture of Asarum sieboldii, Platycodon grandiflorum, and Cinnamomum cassia extracts, on atopic dermatitis in vivo and in vitro.

BACKGROUND: Atopic dermatitis (AD) is a chronic, relapsing skin disease accompanied by itchy and dry skin. AD is caused by complex interactions between innate and adaptive immune response. AD treatment include glucocorticoids and immunosuppressants. However, long-term treatment can have serious side effects. Thus, an effective AD treatment with fewer side effects is required. Natural materials, including herbal medicines, have potential applications. PURPOSE: This study evaluated the in vivo and in vitro therapeutic effects of BS012, a mixture of Asarum sieboldii, Platycodon grandiflorum, and Cinnamomum cassia extracts, on AD and investigated the underlying metabolic mechanisms. METHODS: The anti-inflammatory effects of BS012 were assessed using a mouse model of AD induced by 1­chloro-2,4-dinitrobenzene (DNCB) and in tumor necrosis factor-alpha/interferon-gamma (TNF-α/IFN-γ) stimulated normal human epidermal keratinocytes (NHEKs). In DNCB-induced mice, total dermatitis score, histopathological analysis, and immune cell factors were assessed to evaluate the anti-atopic activity. In TNF-α/IFN-γ-stimulated NHEKs, pro-inflammatory cytokines, chemokines, and related signaling pathways were investigated. Serum and intracellular metabolomics were performed to identify the metabolic mechanism underlying the therapeutic effects of BS012 treatment. RESULTS: In DNCB-induced mice, BS012 showed potent anti-atopic activity, including reducing AD-like skin lesions and inhibiting the expression of Th2 cytokines and thymic stromal lymphopoietin. In TNF-α/IFN-γ-stimulated keratinocytes, BS012 dose-dependently inhibited the expression of pro-inflammatory cytokines and chemokines by blocking nuclear factor-kappa B and signal transducer and activator of transcription signaling pathways. Serum metabolic profiles of mice revealed significant changes in lipid metabolism related to inflammation in AD. Intracellular metabolome analysis revealed that BS012 treatment affected the metabolism associated with inflammation, skin barrier function, and lipid organization of the stratum corneum. CONCLUSION: BS012 exerts anti-atopic activity by reducing the Th2-specific inflammatory response and improving skin barrier function in AD in vivo and in vitro. These effects are mainly related to the inhibition of inflammation and recovery of metabolic imbalance in lipid organization. BS012, a novel combination with strong activity in suppressing the Th2-immune response, could be a potential alternative for AD treatment. Furthermore, the metabolic mechanism in vivo and in vitro using a metabolomics approach will provide crucial information for the development of natural products for AD treatment.

Nutlin-3a induces KRAS mutant/p53 wild type lung cancer specific methuosis-like cell death that is dependent on GFPT2.

BACKGROUND: Oncogenic KRAS mutation, the most frequent mutation in non-small cell lung cancer (NSCLC), is an aggressiveness risk factor and leads to the metabolic reprogramming of cancer cells by promoting glucose, glutamine, and fatty acid absorption and glycolysis. Lately, sotorasib was approved by the FDA as a first-in-class KRAS-G12C inhibitor. However, sotorasib still has a derivative barrier, which is not effective for other KRAS mutation types, except for G12C. Additionally, resistance to sotorasib is likely to develop, demanding the need for alternative therapeutic strategies. METHODS: KRAS mutant, and wildtype NSCLC cells were used in vitro cell analyses. Cell viability, proliferation, and death were measured by MTT, cell counting, colony analyses, and annexin V staining for FACS. Cell tracker dyes were used to investigate cell morphology, which was examined by holotomograpy, and confocal microscopes. RNA sequencing was performed to identify key target molecule or pathway, which was confirmed by qRT-PCR, western blotting, and metabolite analyses by UHPLC-MS/MS. Zebrafish and mouse xenograft model were used for in vivo analysis. RESULTS: In this study, we found that nutlin-3a, an MDM2 antagonist, inhibited the KRAS-PI3K/Akt-mTOR pathway and disrupted the fusion of both autophagosomes and macropinosomes with lysosomes. This further elucidated non-apoptotic and catastrophic macropinocytosis associated methuosis-like cell death, which was found to be dependent on GFPT2 of the hexosamine biosynthetic pathway, specifically in KRAS mutant /p53 wild type NSCLC cells. CONCLUSION: These results indicate the potential of nutlin-3a as an alternative agent for treating KRAS mutant/p53 wild type NSCLC cells.

Analysis of plasma nucleotides in rat by micellar electrokinetic capillary chromatography/electrospray ionization mass spectrometry.

RATIONALE: The aim of this study was to establish a simultaneous quantitative analysis method of nine endogenous nucleotides in rat plasma using micellar electrokinetic capillary chromatography/electrospray ionization mass spectrometry (MEKC/ESI-MS). METHODS: To select the optimum conditions for separation of the nucleotides, various pH, concentrations of running buffers and surfactants were tested. Ammonium acetate (20 mM) containing the surfactant dodecyltrimethylammonium bromide (2 mM, pH 3.5) was selected as the micellar running buffer. The plasma samples were prepared by precipitating the proteins with 2 mM EDTA in 60% ethanol. The samples were analyzed using capillary electrophoresis (CE)/MS and selected ion monitoring (SIM) mode with positive ionization. CE was performed using a silica capillary column in reversed polarity mode. RESULTS: The limits of detection (LODs) and limits of quantification (LOQs) of the nucleotides ranged from 0.05-5 and 2.0-20 µM, respectively. The calibration curves were linear (R(2) >0.99) for all analytes, and the accuracy and precision were within ±15%. The developed method was applied to the analysis of nucleotides in rat plasma that was collected after oral administration of acetaminophen (1000 mg/kg/day) to evaluate the changes in plasma nucleotide levels under hepatotoxic conditions. CONCLUSIONS: Decreased level of GTP and increased level of cytosine nucleotides were found to be associated with liver toxicity, which led to the conclusion that liver toxicity is closely related to changes in nucleotide levels in plasma.

Multireaction monitoring of 12 peptides for lowered immunity screening.

A multireaction monitoring method using high-performance liquid chromatography-tandem mass spectrometry was developed for 12 target peptides for determination of endogenous peptide concentrations in human serum. Chromatographic separation conditions were optimized and recoveries for liquid-liquid extraction, solid-phase extraction (SPE), and ultrafiltration of endogenous peptides from human serum were compared, and the SPE method was selected for 12 targeted peptide extractions. The optimized SPE method gave recoveries higher than 60 % for all targeted peptides. The limit of detection was 10 ng/ml for most peptides, except for N-formyl-methionyl-leucyl-phenylalanine (NFMLP) and adrenocorticotropic hormone (ACTH) (18-39). The limit of detection for these two peptides was 1 ng/ml. The real serum samples of 25 elderly and 23 young people were analyzed using the optimized extraction and analysis method. Half of the 12 peptides were below the limit of quantification, and B-type natriuretic peptide, cholecystokinin, ACTH(7-38), substance P, NFMLP, and valyl-glutamyl-prolyl-isoleucyl-prolyl-tyrosine were quantified in the concentration range from 0.1 to 50 ng/ml. The concentration of ACTH(7-38) was significantly higher in elderly people and that of NFMLP was significantly lower in elderly people compared with young people (p < 0.0001). This result implies that there be a possible relationships between ACTH, NFMLP and lowered immunity.