Recently, abnormal tumor suppressor gene (TSG) methylation has become a hotspot in the research on colorectal cancer (CRC). This study aimed to explore the influence of CHD5 methylation of CRC TSG on its clinical and pathological characteristics. A total of 40 operation samples as well as corresponding tissue specimens were collected from CRC patients treated in the First Affiliated Hospital of Zhengzhou University from January to December in 2014. CHD5 gene methylation in tissue specimens was detected with methylation specific polymerase chain reaction (MSP); moreover, messenger ribose nucleic acid (mRNA) expression of CHD5 in each tissue was tested using reverse transcription-polymerase chain reaction (RT-PCR), and Western blot was applied to detect the expression of CHD5 protein in those tissues and to analyze the correlation between mRNA and protein of cancer tissue CHD5 as well as the relationship between CHD5 methylation and protein expression. Results revealed that the expression rate of CHD5 methylation in 40 normal mucosal tissues, para-carcinoma tissues, adenoma tissues and CRC tissues was 12.5% (5/40), 22.5% (9/40), 47.5% (19/40) and 72.5% (33/40), respectively. The mRNA expression of CHD5 in the above tissues was 0.225±0.276, 0.169±0.231, 0.147±0.159 and 0.013±0.011 and the protein expression of CHD5 was 0.438±0.205, 0.398±0.180, 0.156±0.1 and 0.024±0.311, respectively. Methylation rate of CHD5 was 87% (20/23) in 23 cases of CHD5 protein loss expression and 52.9% (9/17) in 17 cases of CHD5 protein expression. Results of chi-squared test indicated that there was a significant difference in methylation rate (P less than 0.05), that is, the methylation rate of negatively expressed CHD5 protein was obviously higher than positively expressed protein. Thus, it can be concluded that the CHD5 methylation rate rises gradually in the evolution of CRC, which is related to the occurrence and development of CRC. Furthermore, CHD5 mRNA is positively correlated with protein expression and CHD5 gene methylation is associated with protein loss expression. Therefore, TSG CHD5 methylation of rectal cancer has a great effect in influencing its clinical and pathological features.
Journal of biological regulators and homeostatic agents. 0000 Jan [Epub]
J B Liu, Q B Zhou, J Z Xu, G X Wang, W T Yuan
Colorectum surgery department of the First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.