Mex3a promoter hypomethylation can be utilized to diagnose HBV-associated hepatocellular carcinoma: a randomized controlled trial

Abstract

Background: Hepatocellular carcinoma remains a health challenge for humanity. Therefore, there is an urgent need to develop novel biomarkers with high efficiency yet fast ability to meet the requirements of hepatocellular carcinoma treatment.

Methods: A total of 229 patients with HBV-associated hepatocellular carcinoma (HCC), 298 patients with chronic hepatitis B (CHB), and 96 healthy controls were retrospectively analyzed. Methylation levels of the Mex3a promoter in peripheral blood mononuclear cells (PBMCs) were measured using MethyLight to obtain clinical and laboratory parameters.

Results: The Mex3a promoter methylation level in HCC patients (median: 0.289% and interquartile range: 0.126%-0.590%) was significantly lower than that in CHB patients (median: 0.999%, interquartile range: 0.417%-1.268%, and p < 0.001) and healthy people (median: 2.172%, interquartile range: 1.225%-3.098%, and p < 0.001). The Mex3a mRNA levels in HCC patients (median: 12.198 and interquartile range: 3.112-18.996) were significantly higher than those in CHB patients (median: 1.623 and interquartile range: 0.066-6.000, and p < 0.001) and healthy controls (median: 0.329, interquartile range: 0.031-1.547, and p < 0.001). MethyLight data were expressed as a percentage of the methylated reference (PMR) value. The Mex3a PMR value was negatively correlated with the mRNA expression level (Spearman's R = -0.829 and p < 0.001). The Mex3a PMR value of HCC patients was significantly correlated with age (Spearman's R = 0.113 and p = 0.044), and the mRNA level was significantly correlated with ALT (Spearman's R = 0.132 and p = 0.046). The Mex3a promoter methylation levels and mRNA levels were also independent factors in the development of liver cancer. The Mex3a promoter methylation and mRNA levels were better at distinguishing HCC from CHB than AFP [area under the receiver operating characteristic curve (AUC) for predicting HCC vs. CHB: 0.915 vs. 0.715: p < 0.001]. The combined use of AFP and Mex3a methylation levels and mRNA levels further improved the area under the receiver operating characteristic curve.

Conclusion: The presence of Mex3a promoter hypomethylation in hepatocellular carcinoma can be used as a non-invasive biomarker for the early detection of liver cancer.

Keywords: HBV-associated; MethyLight; Mex3a; biomarker; hepatocellular carcinoma.