Jinchun Xing

LC-MS based serum metabonomic analysis for renal cell carcinoma diagnosis, staging, and biomarker discovery.

A LC-MS based method, which utilizes both reversed-performance (RP) chromatography and hydrophilic interaction chromatography (HILIC) separations, has been carried out in conjunction with multivariate data analysis to discriminate the global serum profiles of renal cell carcinoma (RCC) patients and healthy controls. The HILIC was found necessary for a comprehensive serum metabonomic profiling as well as RP separation. The feasibility of using serum metabonomics for the diagnosis and staging of RCC has been evaluated. One-hundred percent sensitivity in detection has been achieved, and a satisfactory clustering between the early stage and advanced-stage patients is observed. The results suggest that the combination of LC-MS analysis with multivariate statistical analysis can be used for RCC diagnosis and has potential in the staging of RCC. The MS/MS experiments have been carried out to identify the biomarker patterns that made great contribution to the discrimination. As a result, 30 potential biomarkers for RCC are identified. It is possible that the current biomarker patterns are not unique to RCC but just the result of any malignancy disease. To further elucidate the pathophysiology of RCC, related metabolic pathways have been studied. RCC is found to be closely related to disturbed phospholipid catabolism, sphingolipid metabolism, phenylalanine metabolism, tryptophan metabolism, fatty acid beta-oxidation, cholesterol metabolism, and arachidonic acid metabolism.

Bladder cancer determination via two urinary metabolites: a biomarker pattern approach

The purpose of this study was to use metabonomic profiling to identify a potential specific biomarker pattern in urine as a noninvasive bladder cancer (BC) detection strategy. A liquid chromatography-mass spectrometry based method, which utilized both reversed phase liquid chromatography and hydrophilic interaction chromatography separations, was performed, followed by multivariate data analysis to discriminate the global urine profiles of 27 BC patients and 32 healthy controls. Data from both columns were combined, and this combination proved to be effective and reliable for partial least squares-discriminant analysis. Following a critical selection criterion, several metabolites showing significant differences in expression levels were detected. Receiver operating characteristic analysis was used for the evaluation of potential biomarkers. Carnitine C9:1 and component I, were combined as a biomarker pattern, with a sensitivity and specificity up to 92.6% and 96.9%, respectively, for all patients and 90.5% and 96.9%, respectively for low-grade BC patients. Metabolic pathways of component I and carnitine C9:1 are discussed. These results indicate that metabonomics is a practicable tool for BC diagnosis given its high efficacy and economization. The combined biomarker pattern showed better performance than single metabolite in discriminating bladder cancer patients, especially low-grade BC patients, from healthy controls.

LC-MS-based serum metabolic profiling for genitourinary cancer classification and cancer type-specific biomarker discovery

Bladder cancer (BC) and kidney cancer (KC) are the first two commonly occurring genitourinary cancers in China. In this study, a comprehensive LC‐MS‐based method, which utilizes both reversed phase liquid chromatography (RPLC) and hydrophilic interaction chromatography (HILIC) separations, has been carried out in conjunction with multivariate data analysis to discriminate the global serum profiles of BC, KC, and noncancer controls. An independent test set consisting of different patients has been used to objectively evaluate the predictive ability of the analysis platform. Excellent sensitivity and specificity have been achieved in detection of KC and BC. The results suggest that serum metabolic profiling could be used for different types of genitourinary cancer diagnosis. Furthermore, cancer type‐specific biomarkers were found through a critical selection criterion. As a result, eicosatrienol, azaprostanoic acid, docosatrienol, retinol, and 14′‐apo‐beta‐carotenal were found as specific biomarkers for BC; and PE(P‐16:0e/0:0), glycerophosphorylcholine, ganglioside GM3 (d18:1/22:1), C17 sphinganine, and SM(d18:0/16:1(9Z)) were found as specific biomarkers for KC. Receiver operating characteristic (ROC) analysis was used for the preliminary evaluation of the biomarkers. These biomarkers have great potential to be used in the clinical diagnosis after further rigorous assessment.

Multiplex immunodetection of tumor markers with a suspension array built upon core–shell structured functional fluorescence-encoded microspheres

A new suspension array built upon laboratory-prepared functional fluorescence-encoded polystyrene beads (FFPBs) was developed for multiplex immunodetection of tumor markers. The FFPBs were synthesized by copolymerizing rhodamine 6G (R6G) and carboxyl function groups on the surface of the seed beads forming a core-shell structure. The fabrication process was facile and the encoding fluorescence intensity of the beads can be precisely controlled by adjusting the quantity of R6G. In present work, we demonstrated that the quantity variation of impregnated R6G had negligible effect on the coupling efficiency of biomolecules onto the surface of the FFPBs. The R6G encoding fluorescence remained good monodispersity upon capture probe coupling and immunocomplex formation. No fluorescence resonance energy transfer was observed between the R6G doped in the bead shell and fluorophore used for antibody labeling. Under the optimal conditions, the proposed suspension array allowed simultaneous detection of alpha-fetoprotein, carcinoembryonic antigen, and prostate specific antigen in the ranges of 0.07-500 ng mL(-1), 1-2000 ng mL(-1), and 0.5-500 ng mL(-1), respectively, with detection limits of 0.0626 ng mL(-1), 0.554 ng mL(-1), and 0.250 ng mL(-1). Test on clinical serum samples demonstrated that the results obtained with suspension array were in good agreement with those of the reference electrochemiluminescence immunoassay method. We conclude that the laboratory-made FFPBs are sufficient as the microcarrier for the construction of suspension array in clinical diagnosis.

Liquid chromatography-mass spectrometry based serum peptidomic approach for renal clear cell carcinoma diagnosis.

Serum peptidomic approach was applied to investigate the peptidomic signature and discover the clinical biomarkers and biomarker patterns for RCC patients. The holistic orthogonal partial least-squares-discriminant analysis (OPLS-DA) based on qualified profile data successfully classified RCC patients from healthy controls, showing 100% sensitivity and specificity. Following critical criteria, several peptides presenting significant differences in serum level were picked out. The unsupervised hierarchical cluster analysis on those peptides was performed, showing 100% sensitivity and 93.3% specificity for RCC diagnosis regarding the present samples. Besides, receiver-operating characteristic (ROC) analysis was applied on single peptide biomarkers, with four peptides showing excellent predictive power. Among them, IYQLNSKLV and AGISMRSGDSPQD are reported for the first time for cancer detection.

Probing minority population of antibiotic-resistant bacteria.

The evolution and spread of antibiotic-resistant pathogens has become a major threat to public health. Advanced tools are urgently needed to quickly diagnose antibiotic-resistant infections to initiate appropriate treatment. Here we report the development of a highly sensitive flow cytometric method to probe minority population of antibiotic-resistant bacteria via single cell detection. Monoclonal antibody against TEM-1 β-lactamase and Alexa Fluor 488-conjugated secondary antibody were used to selectively label resistant bacteria green, and nucleic acid dye SYTO 62 was used to stain all the bacteria red. A laboratory-built high sensitivity flow cytometer (HSFCM) was applied to simultaneously detect the side scatter and dual-color fluorescence signals of single bacteria. By using E. coli JM109/pUC19 and E. coli JM109 as the model systems for antibiotic-resistant and antibiotic-susceptible bacteria, respectively, as low as 0.1% of antibiotic-resistant bacteria were accurately quantified. By monitoring the dynamic population change of a bacterial culture with the administration of antibiotics, we confirmed that under the antimicrobial pressure, the original low population of antibiotic-resistant bacteria outcompeted susceptible strains and became the dominant population after 5hours of growth. Detection of antibiotic-resistant infection in clinical urine samples was achieved without cultivation, and the bacterial load of susceptible and resistant strains can be faithfully quantified. Overall, the HSFCM-based quantitative method provides a powerful tool for the fundamental studies of antibiotic resistance and holds the potential to provide rapid and precise guidance in clinical therapies.

Association of polymorphisms in angiotensin II receptor genes with aldosterone-producing adenoma

SummaryThis study examined the association of polymorphisms in angiotensin II receptor genes (AT1R and AT2R) with the risk for aldosterone-producing adenoma (APA) in a Chinese Han population. Four polymorphisms including rs5182 (573T/C) in exon 4, rs5186 (1166A/C) in 3′-untranslated region (3′-UTR) in AT1R gene and rs5194 (2274G/A) in 3′-UTR, rs1403543 (1675G/A) in intron 1 in AT2R gene were detected in 148 APA patients and 192 normal subjects (serving as control) by using a MGB-Taqman probe. The distribution of genotypes of each locus was in accordance with Hardy-Weinberg Equilibrium (HWE) in the APA and control groups (P>0.05). The allele A frequency at rs5194 was significantly higher in the APA group (0.49) than in the control group (0.35) (χ2=12.08, P=0.001). Subjects with homozygotic genotype AA and heterozygotic genotype GA were at an increased risk for APA as compared to those with GG genotype (OR=2.66, 95% CI=1.45–4.87; OR=1.67, 95% CI=1.02–2.74). Furthermore, rs5194 single-nucleotide polymorphism (SNP) at AT2R gene was significantly associated with APA in additive (OR=1.64, 95% CI=1.21–2.20, P=0.001), dominant (OR=1.94, 95% CI=1.23–3.06, P=0.003), and recessive model (OR=2.01, 95% CI=1.17–3.45, P=0.01). It was concluded that rs5194 polymorphism at AT2R gene was associated with the risk for APA, which may constitute a genetic marker of APA.This study examined the association of polymorphisms in angiotensin II receptor genes (AT 1 R and AT 2 R) with the risk for aldosterone-producing adenoma (APA) in a Chinese Han population. Four polymorphisms including rs5182 (573T/C) in exon 4, rs5186 (1166A/C) in 3′-untranslated region (3′-UTR) in AT 1 R gene and rs5194 (2274G/A) in 3′-UTR, rs1403543 (1675G/A) in intron 1 in AT 2 R gene were detected in 148 APA patients and 192 normal subjects (serving as control) by using a MGB-Taqman probe. The distribution of genotypes of each locus was in accordance with Hardy-Weinberg Equilibrium (HWE) in the APA and control groups (P>0.05). The allele A frequency at rs5194 was significantly higher in the APA group (0.49) than in the control group (0.35) (χ 2=12.08, P=0.001). Subjects with homozygotic genotype AA and heterozygotic genotype GA were at an increased risk for APA as compared to those with GG genotype (OR=2.66, 95% CI=1.45–4.87; OR=1.67, 95% CI=1.02–2.74). Furthermore, rs5194 single-nucleotide polymorphism (SNP) at AT 2 R gene was significantly associated with APA in additive (OR=1.64, 95% CI=1.21–2.20, P=0.001), dominant (OR=1.94, 95% CI=1.23–3.06, P=0.003), and recessive model (OR=2.01, 95% CI=1.17–3.45, P=0.01). It was concluded that rs5194 polymorphism at AT 2 R gene was associated with the risk for APA, which may constitute a genetic marker of APA.

A Study of Human Bladder Cancer by Serum and Urine Metabonomics

National Science Foundation for Fostering Talents in Basic Research of the National Natural Science Foundation of China [J1030415]; Fujian Province Department of Science & Technology, China [2009D023]

Early diagnosis of urinary lithiasis via elementary profile of serum samples

An elemental analysis method was established to monitor the element levels in serum samples of 38 healthy controls and 38 stone patients. Based on the optimized platform combined with multivariate analysis, satisfactory results can be obtained for urinary lithiasis diagnosis with the concentrations of 9 elements, in which Ba, Ga, Sb, and Na are the top 4 elements of statistical significance. The patients could be subdivided into calcareous and non-calcareous stone patients by metallomic profiling; and it is found that Se plays the major role in this classification. This study indicates that serum elementary analysis gives an insight into the possibility of diagnosis of urinary lithiasis, subsequently it may allow estimation of the content subtype of stones. By means of this simple method of elemental profiling in serum, it might allow early prognosis and treatment guide to urinary lithiasis.

Absorption behavior of small biomolecules on carbon nanotube by density functional theory

Abstract Carbon nanotubes (CNTs) are famous one-dimensional function materials with important applications in energy storage and biomedicine industry. Biomolecules adsorbed in CNTs also have enormous potential in drug and gene delivery or disease supervision. With density functional theory, small biomolecules like H2O and CO were packaged into CNTs, which was studied for their interaction and vibrational frequencies. Based on the results, electron density of CNTs would be weaken or dispersed with adsorption of small molecules, while no direct bonding can be observed in electron cloud. Typical vibrational frequencies of them could be used to characterized and distinguished easily both in simulation and experiments.