Development of an AlphaLISA assay to quantify serum core-fucosylated E-cadherin as a metastatic lung adenocarcinoma biomarker.

Lung cancer is the leading cause of cancer-associated deaths worldwide. Non-small cell lung cancer is a heterogeneous condition with variability in prognosis and in individual response to treatment. Thus, the identification of patients with a high risk of metastasis or relapse after surgery would allow better management. There is increasing evidence that glycosylation plays a significant role in biological processes including oncogenic transformation and metastasis. We set up a platform to screen and identify serum glycoproteins as metastasis biomarkers of lung cancer. Concanavalin A affinity chromatography was used to enrich glycoproteins from pooled serum of lung adenocarcinoma patients. The captured glycoproteins were separated with 2-D DIGE combined with nano-LC-MS/MS and identified by database searching. Some differentially expressed cancer-related glycoproteins, such as α-1-antitrypsin, complement C3c, haptoglobin, and E-cadherin, were identified. These glycoproteins were evaluated by Western blotting and Aleuria aurantia lectin staining and several, including E-cadherin, showed increased core-fucosylation during lung cancer progression. We then measured the fucosylation index (FI) of E-cadherin in 154 lung adenocarcinoma patients. In addition, a homogeneous proximity-based AlphaLISA assay to measure the FI of E-cadherin was established. The present study indicates that the FI of E-cadherin could be a potential prognostic marker of metastatic lung adenocarcinoma.

Identification of complement C3a as a candidate biomarker in human chronic hepatitis C and HCV-related hepatocellular carcinoma using a proteomics approach.

Although the significant risk factors for hepatocellular carcinoma (HCC) are well known from epidemiological studies, diagnosis of this disease at an early stage is difficult, and HCC remains one of the leading causes of cancer death worldwide. Thus, to identify any useful HCC-related biomarkers is still a need. We performed SELDI-TOF MS to identify differentially expressed proteins in HCC serum using weak cation exchange protein chips. Protein characterization was performed by 2-DE separation and nano flow LC-MS/MS. A total of 55 sera were collected from HCC patients and compared with those from 48 patients with chronic hepatitis and 9 healthy individuals. A candidate marker of about 8900 Da was detected as differentially expressed in patients with chronic hepatitis C and hepatitis C virus (HCV)-related HCC. We identified this differentially expressed protein as complement C3a. The expression of C3a in HCC sera was further validated by PS20 chip immunoassay and Western blotting. Complement C3a was found to be elevated in patients with chronic hepatitis C and HCV-related HCC. The combination of SELDI-TOF MS and 2-DE provides a solution to identify disease-associated serum biomarkers.