Association between novel genetic variants of Notch signaling pathway genes and survival of hepatitis B virus-related hepatocellular carcinoma

Abstract

Background: Although the Notch pathway plays an important role in formation and progression of hepatocellular carcinoma (HCC), few studies have reported the associations between functional genetic variants and the survival of hepatitis B virus (HBV)-related HCC.

Methods: In the present study, we performed multivariable Cox proportional hazard regression analysis to evaluate associations between 36,101 SNPs in 264 Notch pathway-related genes and overall survival (OS) of 866 patients with HBV-related HCC.

Results: It was found that three independent SNPs (NEURL1B rs4868192, CNTN1 rs444927 and FCER2 rs1990975) were significantly associated with the HBV-related HCC OS. The number of protective genotypes (NPGs) were significantly associated with better survival in a dose-response manner (p_trend <0.001). Compared with the model with sole clinical factors, the addition of protective genotypes to the predict models significantly increased the AUC, i.e., from 72.72% to 75.13% (p = 0.002) and from 72.04% to 74.76 (p = 0.004) for 3-year and 5-year OS, respectively. The expression quantitative trait loci (eQTL) analysis further revealed that the rs4868192 C allele was associated with lower mRNA expression levels of NEURL1B in the whole blood (p = 1.71 × 10^-3), while the rs1990975 T allele was correlated with higher mRNA expression levels of FCER2 in the whole blood and normal liver tissues (p = 3.51 × 10^-5 and 0.033, respectively).

Conclusions: Three potentially functional SNPs of NEURL1B, CNTN1 and FCER2 may serve as potential prognostic biomarkers for HBV-related HCC.

Keywords: Notch signaling pathway; hepatitis B virus; hepatocellular carcinoma; single nucleotide polymorphism; survival.

FIGURE 1

Flowchart of the study design. AUC, area under the curve; eQTL, expression quantitative trait loci; FPRP, false positive report rate; HBV, hepatitis B virus; HCC, hepatocellular carcinoma; MAF, minor allele frequency; OS, overall survival; ROC, receiver operating characteristic; SNPs, single nucleotide polymorphisms.

FIGURE 2

Kaplan–Meier curves of combined protective genotypes and OS of HBV‐related HCC in combined dataset. HBV, hepatitis B virus; HCC, hepatocellular carcinoma; OS, overall survival.

FIGURE 3

HBV‐related HCC survival prediction of the SNPs by ROC curve in combined dataset. (A–C) 1, 3, and 5 years HBV‐related HCC OS prediction by ROC curve; (D) time‐dependent AUC estimation for OS. AUC, area under the curve; HBV, hepatitis B virus; HCC, hepatocellular carcinoma; OS, overall survival; ROC, receiver operating characteristic.

FIGURE 4

eQTL analysis of the significant SNPs and mRNA expression levels in GTEx portal. (A) NEURL1B rs4868192 in whole blood; (B) NEURL1B rs4868192 in normal liver tissue; (C) FCER2 rs1990975 in whole blood; and (D) FCER2 rs1990975 in normal liver tissue. eQTL, expression quantitative trait loci; GTEx, Genotype Tissue Expression; SNPs, single nucleotide polymorphisms.

FIGURE 5

Differential mRNA expression analysis in HCC from the TNMplot database, and the associations between mRNA expression levels in tumor tissues and OS in HCC patients from Kaplan–Meier Plotter database. (A) Adjacent normal tissues versus tumor tissues: NEURL1B; and (B) Survival curve: NEURL1B; (C) adjacent normal tissues versus tumor tissues: CNTN1 and (D) survival curve: CNTN1; (E) adjacent normal tissues versus tumor tissues: FCER2 and (F) survival curve: FCER2. HCC, hepatocellular carcinoma; OS, overall survival.