In this study, we evaluated the reproducibility of abundant urine protein depletion by hexapeptide-based library beads and an antibody-based affinity column using the iTRAQ technique. The antibody-based affinity-depletion approach, which proved superior, was then applied in conjunction with iTRAQ to discover proteins that were differentially expressed between pooled urine samples from hernia and bladder cancer patients. Several proteins, including seven apolipoproteins, TIM, SAA4, and proEGF were further verified in 111 to 203 individual urine samples from patients with hernia, bladder cancer, or kidney cancer. SAA4 was significantly increased in bladder cancer subgroups, whereas ProEGF was significantly decreased in bladder cancer subgroups. Additionally, the combination of SAA4 and ProEGF exhibited higher diagnostic capacity in discriminating bladder cancer from hernia than either marker alone. A marker panel composed by two novel biomarker candidates, SAA4 and proEGF, was first discovered and verified successfully using Western blotting. To the best of our knowledge, the associations of urinary SAA4 and proEGF with bladder tumor and kidney cancer have not been mentioned before. In the present study, we discovered and verified SAA4 and proEGF as potential bladder cancer biomarker for the first time.

Lung cancer is the leading cause of cancer-related death worldwide. Both diagnostic and prognostic biomarkers are urgently needed to increase patient survival. In this study, we identified/quantified 1763 proteins from paired adenocarcinoma (ADC) tissues with different extents of lymph node (LN) involvement using an iTRAQ-based quantitative proteomic analysis. Based on a bioinformatics analysis and literature search, we selected six candidates (ERO1L, PABPC4, RCC1, RPS25, NARS, and TARS) from a set of 133 proteins that presented a 1.5-fold increase in expression in ADC tumors without LN metastasis compared with adjacent normal tissues. These six proteins were further verified using immunohistochemical staining and Western blot analyses. The protein levels of these six candidates were higher in tumor tissues compared with adjacent normal tissues. The ERO1L and NARS levels were positively associated with LN metastasis. Importantly, ERO1L overexpression in patients with early-stage ADC was positively correlated with poor survival, suggesting that ERO1L overexpression in primary sites of early-stage cancer tissues indicates a high risk for cancer micrometastasis. Moreover, we found that knockdown of either ERO1L or NARS reduced the viability and migration ability of ADC cells. Our results collectively provide a potential biomarker data set for ADC diagnosis/prognosis and reveal novel roles of ERO1L and NARS in ADC progression. Molecular & Cellular Proteomics 15:

Background: Hyponatremia is the most common electrolyte disorder in hospitalized patients, and is frequently a marker of a significant underlying disease. The prognostic value of hyponatremia in patients with acute first-ever ischemic stroke is not known. We aimed to analyze whether hyponatremia in the acute stroke stage contributed to the risk of mortality or recurrent stroke in these patients. Methods: We studied 925 patients presenting with acute first-ever ischemic stroke between 2002 and 2004. Sodium levels were obtained on arrival at the emergency room within 3 days of acute stroke onset. Hyponatremia was defined as a serum sodium concentration of 134 mmol/l or less. Clinical presentation, stroke risk factors, associated medical disease, and outcome were recorded. All patients were followed for 3 years for survival analysis. A multivariate Cox proportional hazards model was used to identify risk factors for 3-year mortality in these patients. We also constructed Kaplan-Meier survival curves, and compared groups with hyponatremia and normonatremia by means of log rank tests for significant differences. Results: Among the patients with acute first-ever ischemic stroke, 107 (11.6%) were hyponatremic. Among stroke risk factors, the prevalence of diabetes mellitus was significantly higher among hyponatremic patients (p < 0.001). Prevalence of chronic renal insufficiency was also higher in the hyponatremic group (p = 0.002). Clinical presentations, such as the length of acute ward stay, initial impaired consciousness, and clinical course in acute stroke were similar among normo- and hyponatremic patients. Among the complications, pneumonia and urinary tract infection were significantly higher in hyponatremic than in normonatremic patients. After multivariate logistic regression analysis, diabetes mellitus and chronic renal insufficiency were associated with hyponatremia in these patients. Kaplan-Meier analysis indicated that the survival rate was significantly lower in hyponatremic patients than in normonatremic patients (log rank test; p value <0.001). After multivariate Cox proportional hazards model analysis, hyponatremia was a significant predictor of 3-year mortality in these patients after adjustment for related variables (p value = 0.003, hazard ratio = 2.23, 95% confidence interval: 1.30–3.82). Conclusion: Hyponatremia in the acute stroke stage is a predictor of 3-year mortality in patients with acute first-ever ischemic stroke that is independent of other clinical predictors of adverse outcome.

No abstract

Malignant pleural effusion (MPE) obtained from lung adenocarcinoma may contain potentially useful biomarkers for detection of lung cancer. In this study, we used a removal system for high-abundance proteins followed by one-dimensional SDS-PAGE combined with nano-LC-MS/MS to generate a comprehensive MPE proteome data set with 482 nonredundant proteins. Next, we integrated the MPE proteome and secretome data sets from three adenocarcinoma cell lines, with a view to identifying potential PE biomarkers originating from malignant cells. Four potential candidates, alpha-2-HS-glycoprotein (AHSG), angiogenin, cystatin-C, and insulin-like growth factor-binding protein 2, (IGFBP2), were isolated for preclinical validation using ELISA. Both AHSG and IGFBP2 levels were increased in lung patients with MPE (n = 68), compared to those with nonmalignant pleural effusion (n = 119). Notably, the IGFBP2 level was higher in MPE, compared with that in benign diseases (bacteria pneumonia and tuberculosis pleuritis), and significantly associated with malignancy, regardless of the cancer type. Our data additionally support an extracellular function of IGFBP2 in migration in lung cancer cells. These findings collectively suggest that the adenocarcinoma MPE proteome provides a useful data set for malignancy biomarker research.