Abstract
AIMS: To better understand the role of sodium channel beta subunit (SCNN1B) in the initiation and progression of colorectal cancer (CRC) and to identify potential biomarkers for the early detection and prognosis of CRC. METHODS: A total of 74 pairs of CRC tissues and their adjacent normal tissues were collected between October 2016 and November 2017. The methylation levels of the SCNN1B promoter region in CRC tissues and their adjacent normal tissues were investigated by pyrosequencing. The expression of both SCNN1B mRNA and protein were detected by RT‒qPCR and immunohistochemistry, respectively. RESULTS: The results showed that the methylation levels of the SCNN1B promoter region were significantly higher in CRC tissues than in adjacent normal tissues. The expression levels of SCNN1B mRNA and protein were significantly lower in the CRC tissues than in their adjacent normal tissues. Moreover, Pearson's correlation analysis showed that the methylation levels of the SCNN1B promoter were negatively correlated with the SCNN1B mRNA levels in CRC tissues. In addition, the high methylation levels and low mRNA expression of SCNN1B showed a significant association with advanced tumour stage, increased risk of lymph node metastasis and poor prognosis of CRC patients. CONCLUSION: This study suggested that the decreased expression of SCNN1B due to its promoter hypermethylation may play an important role in the progression and prognosis of CRC, and the methylation levels of the SCNN1B promoter may serve as an effective molecular marker for predicting the progression and prognosis of CRC.