Quantitative and correlation analysis of the DNA methylation and expression of DAPK in breast cancer

Youzhi Zhu; Shuiqin Li; Qingshui Wang; Ling Chen; Kunlin Wu; Yide Huang; Xiangjin Chen; Yao Lin

doi:10.7717/peerj.3084

Quantitative and correlation analysis of the DNA methylation and expression of DAPK in breast cancer

PeerJ. 2017 Mar 14:5:e3084. doi: 10.7717/peerj.3084. eCollection 2017.

Authors

Youzhi Zhu¹, Shuiqin Li², Qingshui Wang², Ling Chen¹, Kunlin Wu¹, Yide Huang², Xiangjin Chen¹, Yao Lin²

Affiliations

¹ Department of Thyroid and Breast Surgery, The First Affiliated Hospital of Fujian Medical University , Fuzhou , China.
² College of Life Sciences, Fujian Normal University , Fuzhou , China.

Abstract

Background: Death-associated protein kinase 1 (DAPK) is an important tumor suppressor kinase involved in the regulation of multiple cellular activities such as apoptosis and autophagy. DNA methylation of DAPK gene was found in various types of cancers and often correlated with the clinicopathological characteristics. However, the mRNA and protein expression of DAPK in the same sample was rarely measured. Thus, it was unclear if the correlation between DAPK gene methylation and clinicopathological parameters was due to the loss of DAPK expression.

Methods: In this study, the DNA methylation rate, mRNA and protein expression of DAPK was quantitatively detected in 15 pairs of breast cancer patient samples including tumor (T) and adjacent non-tumor (N) tissues.

Results: The correlation between DNA methylation rate and mRNA expression, together with the correlation between mRNA and protein expression, was calculated. No correlation was observed between any levels using either the measurement value of each sample or the T/N ratio of each pair.

Discussion: These data suggested that the DNA methylation status of DAPK did not correlate well with its mRNA or protein expression. Extra caution is needed when interpreting the DNA methylation data of DAPK gene in clinical studies.

Keywords: Breast cancer; Correlation; DAPK; DNA methylation.

Grants and funding

This work was funded by the National Natural Science Foundation of China for Young Scholar (31301172) and the Natural Science Foundation of Fujian Province (2016Y0029 and 2016J01538). The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript.