PRKCDBP Methylation is a Potential and Promising Candidate Biomarker for Non-small Cell Lung Cancer

BACKGROUND AND OBJECTIVES: The occurrence and development of lung cancer are closely linked to epigenetic modification. Abnormal DNA methylation in the CpG island region of genes has been found in many cancers. Protein kinase C delta binding protein (PRKCDBP) is a potential tumor suppressor and its epigenetic changes are found in many human malignancies. This study investigated the possibility of PRKCDBP methylation as a potential biomarker for non-small cell lung cancer (NSCLC). METHODS: We measured the methylation levels of PRKCDBP in the three groups of NSCLC tissues. Promoter activity was measured by the dual luciferase assay, with 5'-aza-deoxycytidine to examine the effect of demethylation on the expression level of PRKCDBP. RESULTS: The methylation levels of PRKCDBP in tumor tissues and 3 cm para-tumor were higher than those of distant (> 10 cm) non-tumor tissues. Receiver operating characteristic (ROC) curve analysis between tumor tissues and distant non-tumor tissues showed that the area under the line (AUC) was 0.717. Dual luciferase experiment confirmed that the promoter region was able to promote gene expression. Meanwhile, in vitro methylation of the fragment (PRKCDBP_Me) could significantly reduce the promoter activity of the fragment. Demethylation of 5'-aza-deoxycytidine in lung cancer cell lines A549 and H1299 showed a significant up-regulation of PRKCDBP mRNA levels. CONCLUSION: PRKCDBP methylation is a potential and promising candidate biomarker for non-small cell lung cancer.