Cytoskeleton-associated membrane protein 4 is upregulated in tumor tissues and is associated with clinicopathological characteristics and prognosis in hepatocellular carcinoma

The role of cytoskeleton-associated membrane protein 4 (CKAP4) in hepatocellular carcinoma (HCC) is controversial. The present study aimed to investigate the association between tumor CKAP4 mRNA expression and clinicopathological characteristics and prognosis in patients with HCC. Data relating to CKAP4 mRNA expression in HCC tumor and normal adjacent liver tissues, and clinicopathological characteristics, were downloaded from the Gene Expression Omnibus and The Cancer Genome Atlas databases. The CKAP4 mRNA levels in tumor tissues were compared with those in normal adjacent liver tissues, their association with clinicopathological parameters was analyzed, and diagnostic and prognostic values were evaluated in patients with HCC. In all 4 datasets (total samples, n=693), CKAP4 mRNA levels were significantly higher in tumor tissues compared with adjacent tissues (all P<0.001), with the area under the receiver operating characteristic curve ranging from 0.799–0.898 for HCC diagnosis. In patients with HCC with available clinical data (n=361), the low-level CKAP4 mRNA group exhibited a lower body mass index (P=0.005), higher α-fetoprotein level (P<0.001), more frequent adjacent liver tissue inflammation (P<0.001), poorer tumor histological grade (P<0.001), higher Ishak fibrosis score (P=0.035) and a more advanced tumor node metastasis (TNM) stage (P=0.014) compared with the high-level CKAP4 mRNA group. Patients stratified by all the above parameters, except for TNM stage, exhibited significantly different expression of tissue CKAP4 mRNA (P<0.05–0.001). Furthermore, higher CKAP4 mRNA levels were observed in patients who died within one year following diagnosis compared with those who survived >3 years (P=0.003). The high-level CKAP4 mRNA group also exhibited lower overall survival (OS) and disease-free survival (DFS) rates compared with the low-level group [hazard ratio (HR)=1.494; 95% confidence interval (CI), 1.044–2.138; P=0.028] for OS and (HR=1.616; 95% CI, 1.022–2.555; P=0.040) for DFS. The results of the present study suggest that CKAP4 mRNA is upregulated in HCC tumor tissues compared with normal adjacent tissues, and is associated with poor clinical prognosis, pathological features and survival in patients with HCC. Thus, CKAP4 is a potential biomarker for HCC diagnosis and prognosis.