Phosphorylation of elongation factor-2 kinase differentially regulates the enzyme's stability under stress conditions

Chronic infection with hepatitis B virus (HBV) is associated with the majority of cases of hepatocellular carcinoma (HCC) in China. Despite this, there is no effective method for the early detection of HBV-induced liver cancer. Aberrant fucosylation is known to occur during the development of HCC. We, therefore, developed a method of applying matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) to analyze the relationship between aberrant fucosylation, tumor genesis and progression of HBV-associated HCC, and to establish proteomic profiling of serum for early diagnosis of HCC. The MALDI-TOF MS was based on Lens culinaris agglutinin (LCA) lectin magnetic beads and their affinity for separation. The method was applied initially to a 'training' cohort of 111 serum samples obtained from subjects in China with no liver disease (n=26), chronic hepatitis B without cirrhosis (n=21), HBV-infected cirrhosis (n=32), or HBV-infected HCC (n=32). In contrast to previous findings, the results of our profiling analysis demonstrated defucosylation on some of the glycoproteins involved in HCC. HCC was then diagnostically classified in a 'blind test' cohort (n=96). In this group we demonstrated that, HCC could be distinguished from all serum samples, HBV-associated chronic liver disease, and HBV-associated cirrhosis with a sensitivity/specificity of 70%/70%, 78%/74%, and 81%/82%, respectively. When combined with serum alpha-fetoprotein detection (AFP>20 ng/mL), the sensitivity/specificity improved to 78%/88%, 85%/88%, and 89%/91%, respectively. In conclusion, serum glycoprotein fucosylation abnormalities have diverse forms in patients with HCC. MALDI-TOF MS profiling of aberrant serum fucosylated glycoproteins distinguished HCC from controls with high accuracy.