Evaluation of HAAH/humbug quantitative detection in the diagnosis of hepatocellular carcinoma.
Human aspartyl-(asparaginyl)-β-hydroxylase (HAAH) is a type 2 transmembrane protein and an α-ketoglutarate-dependent dioxygenase that can stereospecifically catalyze the post-translational hydroxylation reaction of β-carbon atoms of aspartic acid and asparagine residues present in epidermal growth factor-like domains of certain specific proteins. Humbug is a truncated isoform of aspartyl (asparaginyl) β-hydroxylase that lacks the catalytic domain. A series of reports demonstrated that overexpression of HAAH/humbug was identified in hepatocellular carcinoma (HCC) and various tumor tissues. However, the prognostic value of HAAH/humbug expression in HCC remains unclear. The purpose of this study was to investigate the expression of the HAAH/humbug gene at the mRNA and protein levels in HCC and to assess the overexpression of HAAH/humbug as a diagnostic and prognostic marker in HCC. HAAH/humbug mRNA levels were measured in 120 HCCs and 40 paired non-tumor liver tissues by molecular beacon (MB) quantitative RT-PCR. Immunohistochemical staining was used to detect the protein level of the HAAH/humbug in the same specimens. ROC analysis was performed based on the expression levels of the HAAH/humbug gene in 120 cases of HCC tissues and 40 cases of adjacent non-tumor liver tissues. The results showed that 117 (97.5%) of the 120 frozen sections of patients with HCCs had HAAH/humbug-positive immunoreactivity, whereas the 40 adjacent non-tumor liver tissues exhibited no staining. Higher levels of HAAH/humbug mRNA were found in 114 (95%) of the 120 HCC tissues relative to the adjacent cancer‑free tissue. ROC curve analysis exhibited that the sensitivity was 90.1%, specificity was 97.6% and ROC AUC was 0.986. The specific value of HAAH/β-actin abundance used as a cut‑off point was 0.315, while the gene copy number (7.35 copies/µl) was used a as cut‑off point, with sensitivity being 99.2%, specificity 96.7% and the ROC AUC used 0.990. No statistically significant difference was observed for these two factors. HAAH/humbug expression levels were upregulated in almost all the HCC tissues when compared to the adjacent cancer-free tissue, irrespective of the cut‑off point used. Results of the present study suggested that HAAH/humbug is a potential diagnostic and prognostic biomarker for the treatment of HCC.
Faculty of Life Science, Northwest University, Xi'an, Shaanxi 710069, P.R. China.
Tian
T
Xue
Department of Microbiological Test, Nantong Center for Disease Control and Prevention, Nantong, Jiangsu 226007, P.R. China.
Jing
J
Su
Faculty of Life Science, Northwest University, Xi'an, Shaanxi 710069, P.R. China.
Hongmin
H
Li
Department of Microbiology, The Fourth Military Medical University, Xi'an, Shaanxi 710072, P.R. China.
Xiaoping
X
Xue
D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis* / Q000201:enzymology / Q000235:genetics / Q000601:surgery; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007527:Isoenzymes / Q000235:genetics; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000201:enzymology / Q000235:genetics / Q000601:surgery; D008297:Male; D008875:Middle Aged; D006899:Mixed Function Oxygenases / Q000032:analysis* / Q000235:genetics / Q000378:metabolism; D012372:ROC Curve; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods; D012680:Sensitivity and Specificity
D014408:Biomarkers, Tumor; D007527:Isoenzymes; D006899:Mixed Function Oxygenases; C058291:aspartic acid 2-oxoglutarate-dependent dioxygenase