Disease-specific haptoglobin-β chain N-glycosylation as biomarker to differentiate non-small cell lung cancer from benign lung diseases

Abstract

Background: The association of pathological states with N-glycosylation of haptoglobin-β has attracted increasing attention. Materials & Methods: In the present study, disease-specific haptoglobin-β (DSHp-β) was separated from serum immunoinflammation-related protein complexes (IIRPCs) of 600 participants including 300 patients with benign lung diseases (BLDs) and 300 patients with non-small cell lung cancer (NSCLC). The enriched glycopeptides of the tryptic digests of the DSHp-β were analyzed using matrix assisted laser desorption/ionization-Fourier transform ion cyclotron resonance mass spectrometry (MALDI-FTICR MS). Results: 20 of glycopeptides were detected for each sample. The statistical analysis has indicated that significant changes in the sialylation of DSHp-β between BLDs and NSCLC patients were observed. The age- and sex-matched participants were randomly clarified into the training set and the validation set. Receiver operating characteristic (ROC) analysis has revealed that the level ratio of glycopeptides (G2G3/G2G3S4) at the sites of Asn207/211 has potential capability to distinguish BLDs from NSCLC, with the sensitivity of 74.4%, the specificity of 82.8%, and the area under curve (AUC) of 0.805. Conclusion: The glycosylation of DSHp-β can distinguish NSCLC from BLDs with high diagnostic accuracy compared with current clinical available serum markers.

Keywords: disease-specific haptoglobin β chain; glycosylation; lung diseases; matrix assisted laser desorption/ionization-mass spectrometry.; pathological state.

Figure 1

Workflow chart. NSCLC, non-small cell lung cancer; BLDs, benign lung diseases; native-PAGE, native polyacrylamide gel electrophoresis; SDS-PAGE, sodium dodecylsulfate-polyacrylamide gel electrophoresis; MALDI-FTICR MS, matrix-assisted laser desorption/ionization-Fourier transform ion cyclotron resonance mass spectrometer.

Figure 2

Representative mass spectra of the glycopeptides from tryptic digests of DSHp-β from one NSCLC patient (a) and one BLDs patient (b).

Figure 3

Correlation analysis between DSHp-β glycopeptides in BLDs or NSCLC patients. Green, positive correlation; red, negative correlation. The number in grid indicates the Spearman correlation coefficient.

Figure 4

Scatter plots and diagnostic performance of serum clinical markers and G2G3/G2G3S4 at the Asn207/211 sites. *, p < 0.05; **, p < 0.01; ***, p < 0.001; NS, no significance.