CYLD downregulation is correlated with tumor development in patients with hepatocellular carcinoma

The cylindromatosis (CYLD) gene is involved in tumor progression by acting as a negative regulator of nuclear factor-κB (NF-κB). However, the clinical significance of CYLD in patients with hepatocellular carcinoma (HCC) remains unclear. To demonstrate the clinical significance of CYLD expression, we analyzed CYLD gene expression in 124 paired HCC and non-tumor tissues using quantitative reverse transcription-polymerase chain reaction (qRT-PCR). CYLD gene expression was detected in the patients and the cut-off value was determined by the median value of tumor-to-non-tumor (T/N) ratio. qRT-PCR analysis showed that a low CYLD expression was associated with a high serum α-fetoprotein (AFP) value. Patients in the low CYLD expression group exhibited poorer overall survival compared to those in the high expression group (P=0.0406). Protein expression of CYLD was also investigated in 70 patients with HCC using immunohistochemistry. The findings showed that CYLD protein expression in tumor tissue was associated with CYLD gene expression (P=0.031). The findings of the present study suggest that CYLD is clinically associated with tumor development in HCC patients.