Identification of ENO1 as a potential sputum biomarker for early-stage lung cancer by shotgun proteomics.

Abstract

BACKGROUND:

Lung cancer is the leading cancer killer. Early detection will reduce the related deaths. The objective of this study was to identify potential biomarkers for early-stage lung cancer in sputum supernatant.

MATERIALS AND METHODS:

Using shotgun proteomics, we detected changes in protein profiles that were associated with lung cancer by analyzing sputum supernatants from 6 patients with early-stage lung cancer and 5 cancer-free controls. Using western blotting, we validated the proteomic results in 22 lung cancer cases and 22 controls. Using enzyme-linked immunosorbent assay (ELISA), we evaluated the diagnostic performance of the biomarker candidates in an independent set of 35 cases and 36 controls.

RESULTS:

Proteomics identified 8 biomarker candidates for lung cancer. Western blotting validation of the candidates showed that enolase 1 (ENO1) displayed a higher expression level in patients with cancer than in cancer-free individuals (P = .015). ELISA revealed that the assessment of ENO1 expression in sputum supernatant had 58.33% sensitivity and 80.00% specificity in distinguishing patients with stage I lung cancer from cancer-free individuals.

CONCLUSION:

The analysis of protein biomarkers in sputum may provide a potential approach for the early detection of lung cancer. Future validation of all the candidates defined by shotgun proteomics in a large cohort study may help develop additional biomarkers that can be added to ENO1 to provide more diagnostic efficacy for lung cancer.

• Authors: Lei Yu, Jun Shen, Kaiissar Mannoor, Maria Guarnera, Feng Jiang
• Journal: Clinical lung cancer (Clin Lung Cancer) Vol. 15 Issue 5 Pg. 372-378.e1 (Sep 2014) ISSN: 1938-0690 [Electronic] United States
• PMID: 24984566 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S., Validation Study)
• Copyright: Copyright © 2014 Elsevier Inc. All rights reserved.

Chemical References

• Biomarkers, Tumor
• DNA-Binding Proteins
• Tumor Suppressor Proteins
• ENO1 protein, human
• Phosphopyruvate Hydratase

Topics

• Aged
• Biomarkers, Tumor (genetics, metabolism)
• Blotting, Western
• Case-Control Studies
• DNA-Binding Proteins (genetics, metabolism)
• Enzyme-Linked Immunosorbent Assay
• Female
• Gene Expression Regulation, Neoplastic
• Humans
• Lung Neoplasms (genetics, pathology)
• Male
• Neoplasm Staging
• Phosphopyruvate Hydratase (genetics, metabolism)
• Proteomics (methods)
• Sensitivity and Specificity
• Sputum (metabolism)
• Tumor Suppressor Proteins (genetics, metabolism)