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


CONCLUSIONS
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.
Department of Thyroid and Breast Surgery, The First Affiliated Hospital of Fujian Medical University , Fuzhou , China.
Youzhi
Y
Zhu
College of Life Sciences, Fujian Normal University , Fuzhou , China.
Shuiqin
S
Li
College of Life Sciences, Fujian Normal University , Fuzhou , China.
Qingshui
Q
Wang
Department of Thyroid and Breast Surgery, The First Affiliated Hospital of Fujian Medical University , Fuzhou , China.
Ling
L
Chen
Department of Thyroid and Breast Surgery, The First Affiliated Hospital of Fujian Medical University , Fuzhou , China.
Kunlin
K
Wu
College of Life Sciences, Fujian Normal University , Fuzhou , China.
Yide
Y
Huang
Department of Thyroid and Breast Surgery, The First Affiliated Hospital of Fujian Medical University , Fuzhou , China.
Xiangjin
X
Chen
College of Life Sciences, Fujian Normal University , Fuzhou , China.
Yao
Y
Lin
Breast cancer; Correlation; DAPK; DNA methylation