Differential detection of S100A8 in transitional cell carcinoma of the bladder by pair wise tissue proteomic and immunohistochemical analysis

Trained immunity as a molecular mechanism for BCG immunotherapy in bladder cancer

Intravesical BCG instillation is the gold-standard adjuvant immunotherapy for patients with high-risk non-muscle-invasive bladder cancer. However, the precise mechanism of action by which BCG asserts its beneficial effects is still unclear. BCG has been shown to induce a non-specific enhancement of the biological function in cells of the innate immune system, creating a de facto heterologous immunological memory that has been termed trained immunity. Trained immunity or innate immune memory enables innate immune cells to mount a more robust response to secondary non-related stimuli after being initially primed (or trained) by a challenge such as BCG. BCG-induced trained immunity is characterized by the metabolic rewiring of monocyte intracellular metabolism and epigenetic modifications, which subsequently lead to functional reprogramming effects, such as an increased production of cytokines, on restimulation. Results from BCG vaccination studies in humans show that trained immunity might at least partly account for the heterologous beneficial effects of BCG vaccination. Additionally, immunity might have a role in the effect of BCG immunotherapy for bladder cancer. Based on these indications, we propose that trained immunity could be one of the important mechanisms mediating BCG immunotherapy and could provide a basis for further improvements towards a personalized approach to BCG therapy in non-muscle-invasive bladder cancer.

Calgranulin A (S100A8) Immunostaining: A Future Candidate for Risk Assessment in Patients with Non-Muscle-Invasive Bladder Cancer (NMIBC)

INTRODUCTION

There is an urgent need to identify patients with bladder cancer (BC) who are at high risk of recurrence or progression. Calgranulin A is a strong marker for muscle-invasive or advanced BC and recent studies have shown its potential for identifying patients at risk even in non-muscle-invasive bladder cancer (NMIBC). The present study examines risks of recurrence and progression dependent on immunostaining with calgranulin A in NMIBC.

METHODS

Calgranulin A protein expression was evaluated through the immunohistochemistry of 158 randomly selected, transurethrally resected BC specimens of separate patients (pTa 89, pT1 69) using tissue microarrays. Kaplan-Meier survival analysis and Cox regression were performed to determine whether calgranulin A expression is associated with recurrence-free survival (RFS), progression-free survival (PFS), or cancer-specific survival (CSS).

RESULTS

Calgranulin A expression is significantly different between pTa and pT1 tumors (p = 0.000, Mann-Whitney U test) and between tumor grades (p = 0.015, Kruskal-Wallis test). Kaplan-Meier estimates produced significant results for low and high calgranulin A expression concerning RFS [5y-RFS 70.4 ± 4.0% vs. 35.9 ± 12.5%, median RFS not reached (NR) vs. 12.0 ± 4.4 month, p = 0.029, log-rank test], PFS (5y-PFS 90.3 ± 2.7% vs. 51.5 ± 14.0%, median PFS NR in both groups, p = 0.000, log-rank test), and CSS (5y-CSS 92.9 ± 2.6% vs. 70.7 ± 12.4%, median CSS NR in both groups, p = 0.005, log-rank test). Calgranulin A remained an independent factor for RFS (p = 0.024, HR 2.43) and PFS (p = 0.002, HR 5.92) according to the multivariate Cox regression model.

CONCLUSIONS

Calgranulin A expression in NMIBC, detected through immunohistochemistry, is a promising marker for the identification of NMIBC patients at high risk of recurrence and progression.

A review of S100 protein family in lung cancer

S100 protein family, representing 25 relatively small calcium binding proteins, has been reported to be involved in multiple stages of tumorigenesis and progression. These proteins are considered having potential value to be adopted as novel biomarkers in the detection and accurate prediction of many kinds of tumors, including lung cancer. As the one having the highest morbidity and mortality among all cancers, lung carcinoma is still occult for detection, especially at early stage. S100 proteins take participation in the lung neoplasia through playing intracellular and/or extracellular functions, therefore getting involved in a variety of biological processes such as differentiation, proliferation, and migration. A few members have also been testified to modulate TGF-β/Smad-3 mediated transcriptional activity of target genes involved in tumor promotion. In addition to that, a number of proteins in this family have already been reported to experience an abnormal trend in lung cancer at cell, serum and tissue levels. Thus, S100 proteins may serve as effective biomarkers for suspected or already diagnosed lung cancer patients. In future, S100 protein family might be applied as therapeutic targets in clinical treatment of lung cancer. In this review, we firstly summed up the biological and clinical evidence connecting S100 proteins and lung cancer, which has not been summarized before.

Clinical and in vitro analysis of Osteopontin as a prognostic indicator and unveil its potential downstream targets in bladder cancer

Osteopontin (OPN) plays an important role in cancer progression, however its prognostic significance and its downstream factors are largely elusive. In this study, we have shown that expression of OPN was significantly higher in bladder cancer specimens with higher T-stage or tumor grades. In addition, a high level of OPN was significantly associated with poorer survival in two independent bladder cancer patient cohorts totaling 389 bladder cancer patients with available survival data. We further identified Matrix metallopeptidase 9 (MMP9) and S100 calcium-binding protein A8 (S100A8) were both downstream factors for OPN in bladder cancer specimens and bladder cancer cell lines. Expression of OPN was significantly positively associated with that of MMP9 and S100A8, while overexpression of OPN resulted in upregulation of MMP9 and S100A8, and knockdown of OPN showed consistent downregulation of MMP9 and S100A8 expression levels. Importantly, expression levels of both MMP9 and S100A8 were significantly associated with higher T-stage, higher tumor grade and a shorter survival time in the bladder cancer patients. Interestingly, OPN expression only predicted survival in MMP9-high, but not MMP9-low subgroups, and in S100A8-low but not S100A8-high subgroups. Our results suggest that OPN, MMP9 and S100A8 all play a significant role in bladder cancer progression and are potential prognostic markers and therapeutic targets in bladder cancer. The mechanistic link between these three genes and bladder cancer progression warrants further investigation.

Diagnostic performance of the urinary canine calgranulins in dogs with lower urinary or urogenital tract carcinoma

BACKGROUND

Onset of canine transitional cell carcinoma (TCC) and prostatic carcinoma (PCA) is usually insidious with dogs presenting at an advanced stage of the disease. A biomarker that can facilitate early detection of TCC/PCA and improve patient survival would be useful. S100A8/A9 (calgranulin A/B or calprotectin) and S100A12 (calgranulin C) are expressed by cells of the innate immune system and are associated with several inflammatory disorders. S100A8/A9 is also expressed by epithelial cells after malignant transformation and is involved in the regulation of cell proliferation and metastasis. S100A8/A9 is up-regulated in human PCA and TCC, whereas the results for S100A12 have been ambiguous. Also, the urine S100A8/A9-to-S100A12 ratio (uCalR) may have potential as a marker for canine TCC/PCA. Aim of the study was to evaluate the diagnostic accuracy of the urinary S100/calgranulins to detect TCC/PCA in dogs by using data and urine samples from 164 dogs with TCC/PCA, non-neoplastic urinary tract disease, other neoplasms, or urinary tract infections, and 75 healthy controls (nested case-control study). Urine S100A8/A9 and S100A12 (measured by species-specific radioimmunoassays and normalized against urine specific gravity [S100A8/A9_USG; S100A12_USG], urine creatinine concentration, and urine protein concentration and the uCalR were compared among the groups of dogs.

RESULTS

S100A8/A9_USG had the highest sensitivity (96%) and specificity (66%) to detect TCC/PCA, with specificity reaching 75% after excluding dogs with a urinary tract infection. The uCalR best distinguished dogs with TCC/PCA from dogs with a urinary tract infection (sensitivity: 91%, specificity: 60%). Using a S100A8/A9_USG ≥ 109.9 to screen dogs ≥6 years of age for TCC/PCA yielded a negative predictive value of 100%.

CONCLUSIONS

S100A8/A9_USG and uCalR may have utility for diagnosing TCC/PCA in dogs, and S100A8/A9_USG may be a good screening test for canine TCC/PCA.

The impact of advanced proteomics in the search for markers and therapeutic targets of bladder cancer

Bladder cancer is the most common cancer of the urinary tract and can be avoided through proper surveillance and monitoring. Several genetic factors are known to contribute to the progression of bladder cancer, many of which produce molecules that serve as cancer biomarkers. Blood, urine, and tissue are commonly analyzed for the presence of biomarkers, which can be derived from either the nucleus or the mitochondria. Recent advances in proteomics have facilitated the high-throughput profiling of data generated from bladder cancer-related proteins or peptides in parallel with high sensitivity and specificity, providing a wealth of information for biomarker discovery and validation. However, the transmission of screening results from one laboratory to another remains the main disadvantage of these methods, a fact that emphasizes the need for consistent and standardized procedures as suggested by the Human Proteome Organization. This review summarizes the latest discoveries and progress of biomarker identification for the early diagnosis, projected prognosis, and therapeutic response of bladder cancer, informs the readers of the current status of proteomic-based biomarker findings, and suggests avenues for future work.

Ten Years of Proteomics in Bladder Cancer: Progress and Future Directions

Research efforts targeting the identification of bladder cancer biomarkers have been extensive during the past decade. Investigations have been performed at the genome, transcriptome, proteome, and metabolome levels and outputs have started appearing including the sketching of disease molecular subtypes. Proteins are directly linked to cell phenotype hence they accumulate special interest as both biomarkers and therapeutic targets. Multiple technical challenges exist, of the main, being the protein concentration vast dynamic range and presence of proteins in modified forms. The scope of this review is to summarize the contribution of proteomics research in this quest of bladder cancer biomarkers. To obtain an unbiased and comprehensive overview, the scientific literature was searched for manuscripts describing proteomic studies on urothelial cancer from the last ten years and those including independent verification studies in urine, tissue and blood are briefly presented. General observations include: a) in most cases, suboptimal experimental design including healthy controls in biomarker discovery and frequently biomarker verification, is followed; b) variability in protein findings between studies can be observed, to some extent reflecting complexity of experimental approaches and proteome itself; c) consistently reported biomarkers include mainly plasma proteins and d) compilation of protein markers into diagnostic panels appears the most promising way forward. Two main avenues of research can now be foreseen: targeting integration of the existing disparate data with proteomic findings being placed in the context of existing knowledge on bladder cancer subtypes and in parallel, accumulation of clinical samples to support proper validation studies of promising marker combinations.

High expression of S100A8 gene is associated with drug resistance to etoposide and poor prognosis in acute myeloid leukemia through influencing the apoptosis pathway

S100A8 has been increasingly recognized as a biomarker in multiple solid tumors and has played pivotal roles in hematological malignancies. S100A8 is potentially an indicator for poor survival in acute myeloid leukemia (AML) in retrospective studies. However, the mechanisms of S100A8 are diverse in cancers. In this study, we investigated the correlation of S100A8 at the transcription level with clinical parameters in 91 de novo AML patients and explored its mechanisms of chemoresistance to etoposide in vitro. The transcription level of S100A8 was significantly lower at initial and relapse stages of AML samples than at complete remission (P<0.001) and than in the control group (P=0.0078), while no significant difference could be found between initial and relapse stages (P=0.257). Patients with high transcription levels of S100A8 exhibited a shorter overall survival (P=0.0012). HL-60 cells transfected with S100A8 showed resistance to etoposide with a higher level IC50 value and lower apoptosis rate compared with HL-60 cells transfected with empty vector. Thirty-six genes were significantly downregulated and 12 genes were significantly upregulated in S100A8 overexpression group compared with control group in which 360 genes involved in apoptotic genes array were performed by real-time reverse transcriptase polymerase chain reaction. Among them, the caspase-3, Bcl-2, and Bax were verified by Western blot analysis which indicated that the role of S100A8 in resistance to chemotherapy was closely related with antiapoptosis. In conclusion, critical S100A8 provided useful clinical information in predicting the outcome of AML. The main mechanism of S100A8 which promoted chemoresistance was antiapoptosis.

A Systematic Review of the Diagnostic and Prognostic Value of Urinary Protein Biomarkers in Urothelial Bladder Cancer

For over 80 years, cystoscopy has remained the gold-standard for detecting tumours of the urinary bladder. Since bladder tumours have a tendency to recur and progress, many patients are subjected to repeated cystoscopies during long-term surveillance, with the procedure being both unpleasant for the patient and expensive for healthcare providers. The identification and validation of bladder tumour specific molecular markers in urine could enable tumour detection and reduce reliance on cystoscopy, and numerous classes of biomarkers have been studied. Proteins represent the most intensively studied class of biomolecule in this setting. As an aid to researchers searching for better urinary biomarkers, we report a comprehensive systematic review of the literature and a searchable database of proteins that have been investigated to date. Our objective was to classify these proteins as: 1) those with robustly characterised sensitivity and specificity for bladder cancer detection; 2) those that show potential but further investigation is required; 3) those unlikely to warrant further investigation; and 4) those investigated as prognostic markers. This work should help to prioritise certain biomarkers for rigorous validation, whilst preventing wasted effort on proteins that have shown no association whatsoever with the disease, or only modest biomarker performance despite large-scale efforts at validation.

Comparative serum proteomic analysis of serum diagnosis proteins of colorectal cancer based on magnetic bead separation and maldi-tof mass spectrometry

BACKGROUND

At present, the diagnosis of colorectal cancer (CRC) requires a colorectal biopsy which is an invasive procedure. We undertook this pilot study to develop an alternative method and potential new biomarkers for diagnosis, and validated a set of well-integrated tools called ClinProt to investigate the serum peptidome in CRC patients.

METHODS

Fasting blood samples from 67 patients diagnosed with CRC by histological diagnosis, 55 patients diagnosed with colorectal adenoma by biopsy, and 65 healthy volunteers were collected. Division was into a model construction group and an external validation group randomly. The present work focused on serum proteomic analysis of model construction group by ClinProt Kit combined with mass spectrometry. This approach allowed construction of a peptide pattern able to differentiate the studied populations. An external validation group was used to verify the diagnostic capability of the peptidome pattern blindly. An immunoassay method was used to determine serum CEA of CRC and controls.

RESULTS

The results showed 59 differential peptide peaks in CRC, colorectal adenoma and health volunteers. A genetic algorithm was used to set up the classification models. Four of the identified peaks at m/z 797, 810, 4078 and 5343 were used to construct peptidome patterns, achieving an accuracy of 100% (> CEA, P < 0. 05). Furthermore, the peptidome patterns could differentiate the validation group with high accuracy close to 100%.

CONCLUSIONS

Our results showed that proteomic analysis of serum with MALDI-TOF MS is a fast and reproducible approach, which may provide a novel approach to screening for CRC.

Low- and high-grade bladder cancer appraisal via serum-based proteomics approach

OBJECTIVE

To address the shortcomings of urine cytology and cystoscopy for screening and grading of urinary bladder cancer (BC) we applied a serum-based proteomics approach as a surrogate tactic for rapid BC probing.

METHODS

This study was performed on 90 sera samples comprising of low-grade (LG, n=33) and high-grade (HG, n=32) BC, and healthy controls (HC, n=25). Two-dimensional gel electrophoresis (2DE) tactic was executed to describe serum proteome. MALDI-TOF-MS (MS) was used to identify the characteristics of aberrantly expressed proteins in 2DE and validated using Western blot (WB) and ELISA approach. Receiver operating characteristics (ROC) curve analysis was also performed to determine the clinical usefulness of these proteins to discriminate among LG, HG and HC cohorts.

RESULTS

This comprehensive approach of 2DE, MS, WB and ELISA reveals five differentially expressed proteins. Among them two biomarkers (S100A8 and S100A9) were able to accurately (ROC, 0.946) distinguish 81% of BC (LG+HG) cases compared to HC with highest sensitivity and specificity. With a comparable tactic, two biomarkers (S100A8 and S100A4) were able to precisely (ROC, 0.941) discriminate 92% of LG cases from HG with utmost sensitivity and specificity.

CONCLUSIONS

Serum proteomics probing appears to be an encouraging and least-invasive tactic for screening and grading of BC.

Measurement of urinary canine S100A8/A9 and S100A12 concentrations as candidate biomarkers of lower urinary tract neoplasia in dogs

Members of the S100 family of calcium-binding proteins (S100A8, A9, and A12; calgranulins) have been associated with inflammation and cancer in human beings. Proteins S100A8 and A9 were overexpressed in human patients with transitional cell carcinoma (TCC) and prostate carcinoma (PCA), suggesting their potential as biomarkers for diagnosing and/or predicting the progression of such neoplasms. Calgranulins have not been studied in dogs with TCC or PCA. Established in-house immunoassays were validated and found suitable for measuring S100A8/A9 and S100A12 in canine urine samples to allow the study of the role of these biomarkers in dogs with TCC or PCA. Urinary calgranulin concentrations were not affected by blood contamination (e.g., due to cystocentesis), and should be normalized against urine specific gravity or urinary creatinine concentration. Urinary calgranulin concentrations were significantly increased in 11 dogs with TCC or PCA (untreated) compared to 42 healthy dogs, and the ratio between S100A8/A9 and S100A12 was significantly higher in 11 dogs with TCC or PCA than in 10 dogs diagnosed with a urinary tract infection, suggesting that calgranulins are potential biomarkers for TCC or PCA in canine patients. The clinical utility of measuring urinary calgranulins in dogs with suspected TCC or PCA warrants further investigation.

Identification of kininogen-1 as a serum biomarker for the early detection of advanced colorectal adenoma and colorectal cancer

Background

Serum markers represent potential tools for the detection of colorectal cancer (CRC). The aim of this study was to obtain proteomic expression profiles and identify serum markers for the early detection of CRC.

Methods

Proteomic profiles of serum samples collected from 35 healthy volunteers, 35 patients with advanced colorectal adenoma (ACA), and 40 patients with CRC were compared using Clinprot technology. Using enzyme-linked immunosorbent assays (ELISAs), 366 sera samples were additionally analyzed, and immunohistochemistry studies of 400 tissues were used to verify the expression of kininogen-1 and its value in the early detection of CRC.

Results

Predicting models were established among the three groups, and kininogen-1 was identified as a potential marker for CRC using Clinprot technology. ELISAs also detected significantly higher serum kininogen-1 levels in ACA and CRC patients compared to controls (P<0.05). Furthermore, the area under the receiver operating characteristic curve (AUC) for serum kininogen-1 in the diagnosis of ACA was 0.635 (P = 0.003), and for serum carcinoembryonic antigen (CEA) was 0.453 (P = 0.358). The sensitivity, specificity, and accuracy of serum kininogen-1 for diagnosing Duke’s stage A and B CRC was 70.13%, 65.88%, and 67.90%, respectively, whereas serum CEA was 38.96%, 85.88%, and 63.58%, respectively. Moreover, immunohistochemistry showed that expression of kininogen-1 was significantly higher in CRC and ACA tissues than in normal mucosa (48.39% vs. 15.58% vs. 0%, P<0.05).

Conclusions

These results suggest that Clinprot technology provides a useful tool for the diagnosis of CRC, and kininogen-1 is a potential serum biomarker for the early detection of advanced colorectal adenoma and CRC.

Serum peptidome patterns of colorectal cancer based on magnetic bead separation and MALDI-TOF mass spectrometry analysis

Background. Colorectal cancer (CRC) is one of the most common cancers in the world, identification of biomarkers for early detection of CRC represents a relevant target. The present study aims to determine serum peptidome patterns for CRC diagnosis. Methods. The present work focused on serum proteomic analysis of 32 health volunteers and 38 CRC by ClinProt Kit combined with mass spectrometry. This approach allowed the construction of a peptide patterns able to differentiate the studied populations. An independent group of serum (including 33 health volunteers, 34 CRC, 16 colorectal adenoma, 36 esophageal carcinoma, and 31 gastric carcinoma samples) was used to verify the diagnostic and differential diagnostic capability of the peptidome patterns blindly. An immunoassay method was used to determine serum CEA of CRC and controls. Results. A quick classifier algorithm was used to construct the peptidome patterns for identification of CRC from controls. Two of the identified peaks at m/z 741 and 7772 were used to construct peptidome patterns, achieving an accuracy close to 100% (>CEA, P < 0.05). Furthermore, the peptidome patterns could differentiate validation group with high accuracy. Conclusions. These results suggest that the ClinProt Kit combined with mass spectrometry yields significantly higher accuracy for the diagnosis and differential diagnosis of CRC.

Serum peptidome patterns for early screening of esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is one of the most common cancers in the world. Early diagnosis is critical for guiding the therapeutic management of ESCC. The present study aims to determine serum peptidome patterns for diagnosing ESCC. To identify novel peptidome patterns for diagnosing ESCC, sera from 31 healthy volunteers and 32 ESCC patients were subjected to a comparative proteomic analysis using a ClinProt™ Kit combined with mass spectrometry (MS). This approach enables the determination of peptidome patterns that can differentiate between ESCC sera and sera from healthy volunteers. For further validation, the diagnostic and differential diagnostic capabilities of the peptidome patterns were verified blindly by using an independent group of sera, consisting of sera from 31 ESCC patients, 33 healthy volunteers, 38 colorectal patients, and 36 gastric cancer patients. A Quick Classifier Algorithm was used to construct the peptidome patterns for the identification of ESCC from the control samples. Five of the identified peaks at mass to charge ratios 759, 786, 1,866, 3,316, and 6,634 were used to construct the peptidome patterns with almost 100% accuracy. Furthermore, the peptidome patterns could also differentiate the validation group with high accuracy. These results suggest that the ClinProt™ Kit combined with MS achieves significantly high accuracy for ESCC diagnosis and differential diagnosis.

Serum peptidome patterns of breast cancer based on magnetic bead separation and mass spectrometry analysis

Background

Breast cancer is one of the most common cancers in the world, and the identification of biomarkers for the early detection of breast cancer is a relevant target. The present study aims to determine serum peptidome patterns for screening of breast cancer.

Methods

The present work focused on the serum proteomic analysis of 36 healthy volunteers and 37 breast cancer patients using a ClinProt Kit combined with mass spectrometry (MS). This approach allows the determination of peptidome patterns that are able to differentiate the studied populations. An independent group of sera (36 healthy volunteers and 37 breast cancer patients) was used to verify the diagnostic capabilities of the peptidome patterns blindly. An immunoassay method was used to determine the serum mucin 1 (CA15-3) of validation group samples.

Results

Support Vector Machine (SVM) Algorithm was used to construct the peptidome patterns for the identification of breast cancer from the healthy volunteers. Three of the identified peaks at m/z 698, 720 and 1866 were used to construct the peptidome patterns with 91.78% accuracy. Furthermore, the peptidome patterns could differentiate the validation group achieving a sensitivity of 91.89% (34/37) and a specitivity of 91.67% (33/36) (> CA 15–3, P < 0.05).

Conclusions

These results suggest that the ClinProt Kit combined with MS shows great potentiality for the diagnosis of breast cancer.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1501556838687844

Urinary protein profiling by liquid chromatography/tandem mass spectrometry: ADAM28 is overexpressed in bladder transitional cell carcinoma

Bladder cancer is the most common urological cancer with higher incidence rate in the endemic areas of Blackfoot disease (BFD) in southern Taiwan. The aim of this study was to utilize the proteomic approach to establish urinary protein patterns of bladder cancer. The experimental results showed that most patients with bladder cancer had proteinuria or albuminuria. The urine arsenic concentrations of bladder cancer patients in BFD areas were significantly higher than those patients from non-BFD areas. In the proteomic analysis, the urinary proteome was identified by nano-high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (nano-HPLC/ESI-MS/MS) followed by peptide fragmentation pattern analysis. We categorized 2782 unique proteins of which 89 proteins were identified with at least three unique matching peptide sequences. Among these 89 proteins, thirteen of them were not found in the control group and may represent proteins specific for bladder cancer. In this study, three proteins, SPINK5, ADAM28 and PTP1, were also confirmed by Western blotting and showed significant differential expression compared with the control group. ADAM28 may be used as a possible biomarker of bladder cancer.

Proteomic tissue profiling for the improvement of grading of noninvasive papillary urothelial neoplasia

OBJECTIVES

In 2004, a novel grading system for papillary non-invasive bladder cancer was introduced; low grade (LG) and high grade (HG) in lieu of the former G1, G2, G3. This change allowed for increased reproducibility as well as diminished interobserver variability in histopathological grading among individual pathologists. Matrix Assisted Laser Desorption/Ionization Time of Flight Imaging Mass Spectrometry (MALDI TOF IMS) was evaluated as an automatic and objective tool to assist grading of urothelial neoplasms and to facilitate accuracy.

DESIGN AND METHODS

To separate G1 (LG, n=27) and G3 (HG, n=21) papillary tumors MALDI TOF IMS was performed using an appropriate algorithm. Thereafter, the automatic assignment of a separate G2 (n=31) group was completed.

RESULTS

G1 (LG) and G3 (HG) tumors were separated with an overall cross validation of 97.18%. G2 tumors indicated a true positive rate of 78.3% for LG and 87.5% for HG, respectively.

CONCLUSIONS

MALDI TOF IMS is a powerful support tool to ascertain pathological diagnosis/grading.

Assessment of high-throughput high-resolution MALDI-TOF-MS of urinary peptides for the detection of muscle-invasive bladder cancer

PURPOSE

There is a need for better biomarkers to both detect bladder cancer and distinguish muscle-invasive (stage T2+) from non-invasive (stage Ta/T1) disease. We assess whether MALDI-TOF-MS of the urine peptidome can achieve this.

EXPERIMENTAL DESIGN

We analysed urine from 751 patients with bladder cancer and 127 patients without bladder cancer. Endogenous peptide profiling was performed using a Bruker Ultraflextreme MALDI-TOF-MS.

RESULTS

Significant differences were seen between the spectra of urine from patients with and without T2+ disease. Albumin, total protein and haematuria were also elevated in T2+ patients. Haematuria was detected in 39% of patients with Ta/T1 disease and in 77% of patients with T2+ disease. Class prediction models based on MALDI data produced areas under receiver-operator characteristic curves of up to 0.76 but did not significantly outperform a model based on total protein alone. Many peptides significantly associated with invasive disease are fragments of abundant blood proteins and are also associated with haematuria.

CONCLUSIONS AND CLINICAL RELEVANCE

Microscopic haematuria is strongly associated with invasive disease; even traces of blood/plasma strongly influence the urinary peptidome. This needs to be taken into consideration when using 'omic' methods to search for urinary biomarkers as blood proteins may give false-positive results.

Characterization of ADAM28 as a biomarker of bladder transitional cell carcinomas by urinary proteome analysis

Human urine contains a large number of proteins and peptides (the urinary proteome). Global analysis of the human urinary proteome is important for understanding urinary tract diseases. Bladder cancer is the most common urological cancer with higher incidence rates in endemic areas of Blackfoot disease (BFD) in southern Taiwan. The aim of this study was to use the proteomic approach to establish urinary protein biomarkers of bladder cancer. ADAM28, identified by proteomic approaches and confirmed by Western blotting, showed significant differences compared with normal individuals, so it may be a biomarker of bladder cancer.

Proteomics research on muscle-invasive bladder transitional cell carcinoma

Background

Aimed to facilitate candidate biomarkers selection and improve network-based multi-target therapy, we perform comparative proteomics research on muscle-invasive bladder transitional cell carcinoma. Laser capture microdissection was used to harvest purified muscle-invasive bladder cancer cells and normal urothelial cells from 4 paired samples. Two-dimensional liquid chromatography tandem mass spectrometry was used to identify the proteome expression profile. The differential proteins were further analyzed using bioinformatics tools and compared with the published literature.

Results

A total of 885/890 proteins commonly appeared in 4 paired samples. 295/337 of the 488/493 proteins that specific expressed in tumor/normal cells own gene ontology (GO) cellular component annotation. Compared with the entire list of the international protein index (IPI), there are 42/45 GO terms exhibited as enriched and 9/5 exhibited as depleted, respectively. Several pathways exhibit significantly changes between cancer and normal cells, mainly including spliceosome, endocytosis, oxidative phosphorylation, etc. Finally, descriptive statistics show that the PI Distribution of candidate biomarkers have certain regularity.

Conclusions

The present study identified the proteome expression profile of muscle-invasive bladder cancer cells and normal urothelial cells, providing information for subcellular pattern research of cancer and offer candidate proteins for biomarker panel and network-based multi-target therapy.

Tissue and serum proteomic profiling for diagnostic and prognostic bladder cancer biomarkers

A panel of biomarkers for the early detection of bladder cancer has not yet been identified. Many different molecules, including DNA, RNA or proteins have been reported but none have provided adequate sensitivity for a single-tier screening test or a test to replace cystoscopy. Therefore, multimarker panels are discussed at present to give a more-precise answer to the biomarker quest. Mass spectrometry or 2D gel-electrophoresis have evolved greatly within recent years and are capable of analyzing multiple proteins or peptides in parallel with high sensitivity and specificity. However, transmission of screening results from one laboratory to another is still the main pitfall of those methods; a fact that emphasizes the need for consistent and standardized procedures as suggested by the Human Proteome Organization (HUPO). In this article, recent results in screening approaches and other proteomic techniques used for biomarker evaluation in bladder cancer are discussed with a focus on serum and tissue biomarkers.

A four-gene signature predicts disease progression in muscle invasive bladder cancer

There are no reliable criteria to handle disease progression of muscle invasive bladder cancer (MIBC), which strongly influences patient survival. Therefore, an accurate predicting method to identify progressive MIBC patients is greatly needed. The aim of this study was to identify a genetic signature associated with disease progression in MIBC. To address this issue, we analyzed three independent cohorts (a training set, test set 1 and test set 2) comprising a total of 128 MIBC patients. Microarray gene expression profiling, including gene network analysis, was performed in the training set to identify a gene expression signature associated with disease progression. The prognostic value of the signature was validated in test set 1 and test set 2 by microarray and real-time reverse transcriptase polymerase chain reaction (RT-PCR), respectively. The determination of gene expression patterns by microarray data analysis identified 1,320 genes associated with disease progression. Gene network analysis of the 1,320 genes suggested that IL1B, S100A8, S100A9 and EGFR were important mediators of MIBC progression. We validated this putative four-gene signature in two independent cohorts (log-rank test, P < 0.05 each, respectively) and estimated the predictive value of the signature by multivariate Cox regression analysis (hazard ratio [HR], 6.24; 95% confidence interval [CI], 1.58-24.61; P = 0.009). Finally, signature-based stratification demonstrated that the four-gene signature was an independent predictor of MIBC progression. In conclusion, a molecular signature defined by four genes represents a promising diagnostic tool for the identification of MIBC patients at high risk of progression.

A novel protein kinase D phosphorylation site in the tumor suppressor Rab interactor 1 is critical for coordination of cell migration

RIN1 is a regulator of epithelial cell migration. We identify serine 292 as a novel phosphorylation site for PKD in RIN1. Phosphorylation at this site controls RIN1-mediated inhibition of cell migration by modulating the direct activation of Abl kinases.

The multifunctional signal adapter protein Ras and Rab interactor 1 (RIN1) is a Ras effector protein involved in the regulation of epithelial cell processes such as cell migration and endocytosis. RIN1 signals via two downstream pathways, namely the activation of Rab5 and Abl family kinases. Protein kinase D (PKD) phosphorylates RIN1 at serine 351 in vitro, thereby regulating interaction with 14–3-3 proteins. Here, we report the identification of serine 292 in RIN1 as an in vivo PKD phosphorylation site. PKD-mediated phosphorylation at this site was confirmed with a phospho-specific antibody and by mass spectrometry. We demonstrate that phosphorylation at serine 292 controls RIN1-mediated inhibition of cell migration by modulating the activation of Abl kinases. We further provide evidence that RIN1 in vivo phosphorylation at serine 351 occurs independently of PKD. Collectively, our data identify a novel PKD signaling pathway through RIN1 and Abl kinases that is involved in the regulation of actin remodeling and cell migration.

Urinary proteomics: ready for prime time in urological cancer diagnostics?

The impact of clinical proteomics on the diagnosis and treatment of urological malignancies is modest in comparison with the high expectations of the past. However, most available studies suffer from flawed clinical designs rather than from technical limitations. This article will briefly introduce the main technological approaches taken, their advantages and disadvantages and will highlight the different challenges associated with urinary proteome analysis. Furthermore, several examples of the successful application of urinary clinical proteomics in the field of prostate and bladder cancer will be introduced. These examples suggest careful validation of novel biomarkers, appropriate study designs using blinded cohorts enrolled from appropriate target populations and the standardization of techniques as key elements required for successful urinary proteomics studies. These prerequisites are essential for turning the old promise of a personalized medicine approach into a new reality to optimize patients’ preventive and therapeutic care.

Identification of S100A8-correlated genes for prediction of disease progression in non-muscle invasive bladder cancer

Background

S100 calcium binding protein A8 (S100A8) has been implicated as a prognostic indicator in several types of cancer. However, previous studies are limited in their ability to predict the clinical behavior of the cancer. Here, we sought to identify a molecular signature based on S100A8 expression and to assess its usefulness as a prognostic indicator of disease progression in non-muscle invasive bladder cancer (NMIBC).

Methods

We used 103 primary NMIBC specimens for microarray gene expression profiling. The median follow-up period for all patients was 57.6 months (range: 3.2 to 137.0 months). Various statistical methods, including the leave-one-out cross validation method, were applied to identify a gene expression signature able to predict the likelihood of progression. The prognostic value of the gene expression signature was validated in an independent cohort (n = 302).

Results

Kaplan-Meier estimates revealed significant differences in disease progression associated with the expression signature of S100A8-correlated genes (log-rank test, P < 0.001). Multivariate Cox regression analysis revealed that the expression signature of S100A8-correlated genes was a strong predictor of disease progression (hazard ratio = 15.225, 95% confidence interval = 1.746 to 133.52, P = 0.014). We validated our results in an independent cohort and confirmed that this signature produced consistent prediction patterns. Finally, gene network analyses of the signature revealed that S100A8, IL1B, and S100A9 could be important mediators of the progression of NMIBC.

Conclusions

The prognostic molecular signature defined by S100A8-correlated genes represents a promising diagnostic tool for the identification of NMIBC patients that have a high risk of progression to muscle invasive bladder cancer.

mRNA Expression of S100A8 as a Prognostic Marker for Progression of Non-Muscle-Invasive Bladder Cancer

PURPOSE

S100A8 is a member of the S100 protein family containing 2EF-hand calcium-binding motifs. S100 proteins are involved in the regulation of a number of cellular processes such as cell cycle progression and differentiation. Altered expression of this protein is associated with various diseases and cancers. The present study aimed to evaluate whether S100A8 has prognostic value for non-muscle-invasive bladder cancer (NMIBC).

MATERIALS AND METHODS

A total of 103 primary NMIBC samples obtained by transurethral resection were evaluated. mRNA levels were examined by real-time reverse transcriptase polymerase chain reaction (RT-PCR) analysis. The results were compared with clinico-pathological parameters. The Kaplan-Meier method was applied to plot the curves for progression-free survival. The multivariate Cox regression model was used to identify the independent prognostic factors for progression.

RESULTS

mRNA expression levels of S100A8 were significantly related to the progression of NMIBC. Kaplan-Meier estimates demonstrated significant differences in tumor progression according to the level of S100A8 expression (log-rank test, p<0.001). The multivariate Cox regression model revealed that the S100A8 mRNA expression level (hazard ratio: 12.538; 95% confidence interval: 2.245-70.023, p=0.004) was an independent predictor for disease progression of NMIBC.

CONCLUSIONS

Expression levels of S100A8 might be a useful prognostic marker for disease progression of NMIBC.

Challenges of genomics and proteomics in nephrology

An increasing number of patients suffering from renal diseases and limitations in standard diagnostic and therapeutic approaches has created an intense interest in applying genomics and proteomics in the field of nephrology. Genomics has provided a vast amount of information, linking the gene activity with disease. However, proteomic technologies allow us to understand proteins and their modifications, elucidating properties of cellular behavior that may not be reflected in analysis of gene expression. The application of these innovative approaches has recently yielded the promising new urinary biomarkers for acute kidney injury and chronic kidney disease, thus providing a better insight in renal pathophysiology and establishing the basis for new therapeutic strategies. Despite significant improvements in therapeutics, the mortality and morbidity associated with acute renal failure (ARF) remain high. The lack of early markers for ARF causes an unacceptable delay in initiating therapy. These biomarker panels will probably be useful for assessing the duration and severity of ARF, and for predicting progression and adverse clinical outcomes. Kidney failure leads to the uremic syndrome characterized by accumulation of uremic toxins, which are normally cleared by the kidneys. Proteomics has gained considerable interest in this field, as a new and promising analytical approach to identify new uremic toxins. The urinary proteome as a tool for biomarker discovery is still in its early phase. A major challenge will be the integration of proteomics with genomics data and their functional interpretation in conjunction with clinical results and epidemiology.

Serum biomarkers of renal cell carcinoma assessed using a protein profiling approach based on ClinProt technique

OBJECTIVES

To investigate the possibility of using the ClinProt technique to find serum cancer related diagnostic markers that are able to better discriminate healthy subjects from patients affected by renal cell carcinoma (ccRCC). Renal cell carcinoma is the most common malignancy of the kidney. Biomarkers for early detection, prognosis, follow-up, and differential diagnosis of ccRCC from benign renal lesions are needed in daily clinical practice when imaging is not helpful.

METHODS

Serum of 29 healthy subjects and 33 ccRCC patients was analyzed by the ClinProt/MALDI-ToF technique.

RESULTS

A cluster of 3 peptides (A = m/z 1083 +/- 8 Da, B = m/z 1445 +/- 8 Da and C = m/z 6879 +/- 8 Da) was able to discriminate patients from control subjects. Cross-validation analysis using the whole casistic showed 88% and 96% of sensitivity and specificity, respectively. Moreover, the cluster showed 100% sensitivity for the identification of patients at pT2 (n = 5) and pT3 (n = 8) and 85% for pT1 patients (n = 20). The intensity of peaks A and C continuously decreased from pT1 to pT3, whereas peak B increased in pT1 and pT2.

CONCLUSIONS

These results may be useful to set up new diagnostic or prognostic tools.

Complicated urinary tract infection is associated with uroepithelial expression of proinflammatory protein S100A8

F344 rats chronically infected with Ureaplasma parvum develop two distinct profiles: asymptomatic urinary tract infection (UTI) and UTI complicated by struvite urolithiasis. To identify factors that affect disease outcome, we characterized the temporal host immune response during infection by histopathologic analysis and in situ localization of U. parvum. We also used differential quantitative proteomics to identify distinguishing host cellular responses associated with complicated UTI. In animals in which microbial colonization was limited to the mucosal surface, inflammation was indistinguishable from that which occurred in sham-inoculated controls, and the inflammation resolved by 72 h postinoculation (p.i.) in both groups. However, inflammation persisted in animals with microbial colonization that extended into the deeper layers of the submucosa. Proteome profiling showed that bladder tissues from animals with complicated UTIs had significant increases (P < 0.01) in proteins involved in apoptosis, oxidative stress, and inflammation. Animals with complicated UTIs (2 weeks p.i.) had the highest concentrations of the proinflammatory protein S100A8 (P Collapse

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MESH Headings

• Animals
• Calgranulin A/biosynthesis
• Cytokines/biosynthesis
• Histocytochemistry
• Humans
• Microscopy, Fluorescence
• Proteome/analysis
• Rats
• Ureaplasma/immunology
• Ureaplasma/pathogenicity
• Ureaplasma Infections/immunology
• Ureaplasma Infections/microbiology
• Ureaplasma Infections/pathology
• Urinary Bladder/immunology
• Urinary Bladder/microbiology
• Urinary Bladder/pathology
• Urinary Tract Infections/immunology
• Urinary Tract Infections/microbiology
• Urinary Tract Infections/pathology

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Grants

• K08 DK075651 NIDDK NIH HHS
• K08 DK075651-02 NIDDK NIH HHS
• R01 AI045875 NIAID NIH HHS
• K08DK075651 NIDDK NIH HHS

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Affiliation(s)

Leticia Reyes University of Florida, College of Veterinary Medicine, Department of Infectious Diseases & Pathology, P.O. Box 110880, Gainesville, FL 32611-0880, USA.
Sophie Alvarez
Ayman Allam
Mary Reinhard
Mary B Brown

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Proteomic investigation on chronic bladder irritation in the rat

OBJECTIVES

Interstitial cystitis (IC) is a painful bladder syndrome associated with urinary frequency and urgency. Elusive cause of IC makes its diagnosis only possible by exclusion in many cases. In this study, we used proteomics for identifying disease-associated proteins in a rat model of chronic bladder irritation.

METHODS

Chronic irritation of the rat bladder was caused by a brief (90 seconds) intravesical instillation of 0.2 mL of 0.4 N HCl. Whole bladders were collected at different time points after treatment, snap frozen, and nuclear and cytosolic protein extracts were obtained. Samples were resolved in standard 2-dimensional (2D) gels stained with an improved Coomasie stain or by differential gel electrophoresis (DIGE). Differentially expressed spots were excised and identified by MALDI-TOF MS/MS. Histologic and Western blot analyses were also performed.

RESULTS

Bladder morphology and histologic appearance of bladder sections after HCl treatment reflected hemorrhage, edema, epithelial denudation, detrusor mastocytosis, and eosinophilia. Proteomic analysis of irritated rat bladder revealed marked overexpression of 4 nuclear proteins and marked underexpression of 1 nuclear protein compared with normal rat bladders. Among these proteins, inflammation-associated calgranulin A (over) and smooth muscle protein-22/transgelin (under) showed opposed expression patterns after bladder irritation.

CONCLUSIONS

Presence of mast cells and eosinophils and overexpression of calgranulin A confirm the inflammatory component of HCl-irritated bladder. Altered expression of nuclear proteins is of particular interest because of their possible role as a prognostic marker in inflammatory bladder disorders. However, more studies are needed before clinical application of these findings can be established.

Challenges of using mass spectrometry as a bladder cancer biomarker discovery platform

INTRODUCTION

Bladder cancer (BCa) is one of the most prevalent malignancies worldwide, mostly due to its high recurrence rates. In consequence, the necessity of repeated screening for reappearance demonstrates the urgent need for novel biomarkers as alternatives to invasive standard procedures.

METHODS

Proteomic technologies have emerged as powerful platforms for unbiased biomarker discovery and revolutionized the classical "target-driven" analysis of single marker candidates. Although proteome profiling is still far from demonstrating its full potential in clinical diagnosis, first studies clearly denote its significant potential.

CONCLUSIONS

This review provides a discussion of the challenges related to clinical proteomics using mass spectrometry, emphasizing bladder cancer biomarker discovery. An outline of the technological prerequisites for reliable proteome profiling, data mining and interpretation, as well as, reflections on future trends in the field are provided.

Phosphorylation at Ser244 by CK1 determines nuclear localization and substrate targeting of PKD2

Protein kinase D2 (PKD2), a member of the PKD family of serine/threonine kinases, is localized in various subcellular compartments including the nucleus where the kinase accumulates upon activation of G-protein-coupled receptors. We define three critical post-translational modifications required for nuclear accumulation of PKD2 in response to activation of the CCK2 receptor (CCK2R): phosphorylation at Ser706 and Ser710 within the activation loop by PKC eta leading to catalytic activity and phosphorylation at Ser244 within the zinc-finger domain, which is crucial for blocking nuclear export of active PKD2 by preventing its interaction with the Crm-1 export machinery. We identify CK1delta and epsilon as upstream activated kinases by CCK2R that phosphorylate PKD2 at Ser244. Moreover, nuclear accumulation of active PKD2 is a prerequisite for efficient phosphorylation of its nuclear substrate, HDAC7. Only nuclear, active PKD2 mediates CCK2R-induced HDAC7 phosphorylation and Nur77 expression. Thus, we define a novel, compartment-specific signal transduction pathway downstream of CCK2R that phosphorylates PKD2 at three specific sites, results in nuclear accumulation of the active kinase and culminates in efficient phosphorylation of nuclear PKD2 substrates in human gastric cancer cells.

Characterization of Diabetic Nephropathy by Urinary Proteomic Analysis: Identification of a Processed Ubiquitin Form as a Differentially Excreted Protein in Diabetic Nephropathy Patients

Background: Identification of markers for prediction of the clinical course of diabetic nephropathy remains a major challenge in disease management. We established a proteomics approach for identification of diabetic nephropathy-related biomarkers in urine.

Methods: We used SELDI-TOF mass spectrometry and SAX2 protein arrays to compare protein profiles from urine of 4 defined patient groups. Samples from patients with type 2 diabetes (DM; n = 45) without nephropathy and without microalbuminuria (DM-WNP), patients with DM with macro- or microalbuminuria (DM-NP; n = 38), patients with proteinuria due to nondiabetic renal disease (n = 34), and healthy controls (n = 45) were analyzed. Anionic exchange, reversed-phase fractionation, gel electrophoresis, and mass spectrometry were used to isolate and identify proteins with high discriminatory power.

Results: A protein with m/z 6188 (P &lt;0.0000004) was strongly released in the urine of healthy controls, patients with proteinuria due to nondiabetic disease, and DM-WNP in contrast to DM-NP patients. An m/z 14 766 protein (P &lt;0.00008) was selectively excreted in the urine of DM-NP patients, whereas the protein with m/z 11 774 (P &lt;0.000004) was significantly excreted by patients with proteinuria and DM-NP. The m/z 11 774 and m/z 14 766 mass peaks were identified as β2-microglobulin and UbA52, a ubiquitin ribosomal fusion protein, respectively. The protein with m/z 6188 was identified as a processed form of ubiquitin.

Conclusion: The release of high amounts of UbA52 in urine of DM-NP patients could serve as a diagnostic marker, whereas the lack of the short form of ubiquitin raises interesting questions about the pathophysiology.

Antibody-based Proteomics: From bench to bedside

Over the past 75 years, antibodies have gone from being recognized as disease biomarkers to being used as very powerful therapeutic tools. This evolution has been accelerated by the identification of mAb and the extensive use of immunological tools both at fundamental and clinical levels. In this review, we evaluate how antibodies can be used to assess the proteome of cells or tissues and their relevance for clinical applications. These antibody-based proteomics approaches also require analytical and technological pipelines as well as specific enabling tools which are described. Our first objective was to establish how large-scale datasets (provided by high-throughput studies such as proteomics and transcriptomics) can be integrated with literature searches and clinical data to identify potentially relevant markers against which antibodies should be raised. Then based on an extensive literature review and our experience, we compare the methodologies developed to produce specific antibodies either in vivo or in vitro. This is followed by the description of the validation tools currently available and it also includes the use of antibody-based approaches in the establishment of molecular signatures utilized at the bench and soon available for bedside use.

Biomarkers for prostate cancer

Novel biomarkers for prostate cancer (PCa) are currently being assessed for utility in PCa diagnosis. This article aims to provide concise information on the current findings that impact prostate cancer research. Results of enzyme-linked immunosorbent assays (ELISA) for single biomarkers, quantitative polymerase chain reaction (PCR)-based assays for DNA/RNA markers will be reviewed in addition to high-throughput proteomic profiling of PCa specimens. The advantages/disadvantages of tissue, blood, urine or seminal plasma as sources for potential biomarkers are discussed emphasizing the consequences for PCa diagnosis. In summary, the majority of promising marker candidates available today needs further validation. Some of the identified markers have the potential to yield novel prognostic tools for PCa, provide novel insights into its pathophysiology, and contribute to the establishment of novel treatment strategies.

A review of the S100 proteins in cancer

AIM

In the quest to reduce mortality and morbidity from cancer, there is continued effort to identify novel biomarkers to aid in the early detection and the accurate prediction of tumour behaviour. One group of proteins that is emerging as a potentially important group of markers in multiple tumour types is the S100 family. This review summarises the biological and clinical relevance of these proteins in relation to different tumour types.

METHODS

A literature search was performed using the PubMed database and the reference lists of relevant articles. Single case studies were excluded and only reports with a clinical relevance from 1961 to 2007 were included.

RESULTS

The search yielded over 1000 published articles and reports. Important reports and studies were reviewed, screened and tracked for further relevant publications. Only the most relevant publications are discussed with relation to individual members of the S100 family.

CONCLUSION

There is increasing evidence that altered expression of S100 family members is seen in many cancers including breast, lung, bladder, kidney, thyroid, gastric, prostate and oral cancers. S100 proteins are commonly up-regulated in tumours and this is often associated with tumour progression. In contrast S100A2, S100A11 and S100A9 have been documented as tumour suppressors in some cancers but as tumour promoters in others. This demonstrates the complexity of the family and variability of their functions. Although the precise roles of these proteins in cancer is still to be discovered many of the family are associated with promoting metastases through interactions with matrix metalloproteinases or by acting as chemoattractants. There is also evidence that some members can regulate transcription factors such as p53. S100B already has a role in a clinical setting in the diagnosis and therapeutic monitoring of malignant melanoma. As our understanding of this family develops it is likely that many more members will aid the diagnosis, monitoring and potential treatment of cancers in the future.

A Method To Reduce Gradient Delay Time of NanoLC

A novel method to dramatically reduce the delay time of a nanoLC gradient is described. The gradient is divided into two parts, and each part is formed at different flow rates. The beginning part is formed and delivered to the inlet of the column at a higher-than-normal flow rate. With the formation of the rest of the gradient at a normal flow rate, the whole gradient is further delivered through the column at the same normal flow rate. To form the gradient with the desired slope, the volumetric gradient slope was kept constant, independent of the flow rate. A gradient delay time reduction of 12.5-16 min was observed with the reported method. The resulting gradient profiles and chromatograms were very similar to those obtained with a conventional method. Comparable retention time reproducibility was observed between the two methods.

High resolution proteome/peptidome analysis of body fluids by capillary electrophoresis coupled with MS

All organisms contain thousands of proteins and peptides in their body fluids. A deeper insight into the functional relevance of these polypeptides under different physiological and pathophysiological conditions and the discovery of specific peptide biomarkers would greatly enhance both diagnosis and therapy of specific diseases. Proteomic methods can provide means to accomplish this grand medical vision. In this review, we will focus on the potential use of proteome analysis for clinical applications, such as disease diagnosis and assessment of response to therapy. We focus on CE coupled with MS (CE-MS) and review in detail different aspects of CE-MS coupling and the results obtained using CE-MS analysis of clinically relevant samples. We also discuss clinical applications of the technology for the diagnosis of renal diseases, urogenital cancer, and arteriosclerosis as well as monitoring the responses to therapeutic interventions.

Clinical proteomics and mass spectrometry profiling for cancer detection

A key challenge in the clinical proteomics of cancer is the identification of biomarkers that would enable early detection, diagnosis and monitoring of disease progression to improve long-term survival of patients. Recent advances in proteomic instrumentation and computational methodologies offer a unique chance to rapidly identify these new candidate markers or pattern of markers. The combination of retentate affinity chromatography and mass spectrometry is one of the most interesting new approaches for cancer diagnostics using proteomic profiling. This review presents two technologies in this field, surface-enhanced laser desorption/ionization time-of-flight and Clinprot, and aims to summarize the results of studies obtained with the first of them for the early diagnosis of human cancer. Despite promising results, the use of the proteomic profiling as a diagnostic tool brought some controversies and technical problems, and still requires some efforts to be standardized and validated.