Abstract

The aim of this study is to investigate the methylation and expression of kallikrein 12 gene in triple-negative breast cancer cells. We evaluated the methylation status of the promoter region of kallikrein 12 gene in breast cancer using bisulfite sequencing polymerase chain reaction to compare the expression of kallikrein 12 gene in MDA-MB-231 and breast cancer cells and examined the expression of kallikrein 12 messenger ribonucleic acid by real-time quantitative polymerase chain reaction. In addition, we detected the expression of kallikrein 12 protein using Western blotting. The elevated methylation of the kallikrein 12 promoter in triple-negative cancer cells led to a reduction in its protein and messenger ribonucleic acid levels. But, after the treatment with 5-aza-2'-deoxycytidine, the protein and messenger ribonucleic acid expression increased. The use of 5-aza-2'- deoxycytidine can significantly reduce the level of kallikrein 12 promoter methylation in the MDA-MB-231 cells. These findings suggest that the hypermethylation may be responsible for the reduced gene expression in these cancer cells. In this study, we introduced a new concept and methodology for the treatment and diagnosis of triple-negative breast cancer.