Deregulated Expression of SRC, LYN and CKB Kinases by DNA Methylation and Its Potential Role in Gastric Cancer Invasiveness and Metastasis

PLoS One. 2015 Oct 13;10(10):e0140492. doi: 10.1371/journal.pone.0140492. eCollection 2015.

Abstract

Kinases are downstream modulators and effectors of several cellular signaling cascades and play key roles in the development of neoplastic disease. In this study, we aimed to evaluate SRC, LYN and CKB protein and mRNA expression, as well as their promoter methylation, in gastric cancer. We found elevated expression of SRC and LYN kinase mRNA and protein but decreased levels of CKB kinase, alterations that may have a role in the invasiveness and metastasis of gastric tumors. Expression of the three studied kinases was also associated with MYC oncogene expression, a possible biomarker for gastric cancer. To understand the mechanisms that regulate the expression of these genes, we evaluated the DNA promoter methylation of the three kinases. We found that reduced SRC and LYN methylation and increased CKB methylation was associated with gastric cancer. The reduced SRC and LYN methylation was associated with increased levels of mRNA and protein expression, suggesting that DNA methylation is involved in regulating the expression of these kinases. Conversely, reduced CKB methylation was observed in samples with reduced mRNA and protein expression, suggesting CKB expression was found to be only partly regulated by DNA methylation. Additionally, we found that alterations in the DNA methylation pattern of the three studied kinases were also associated with the gastric cancer onset, advanced gastric cancer, deeper tumor invasion and the presence of metastasis. Therefore, SRC, LYN and CKB expression or DNA methylation could be useful markers for predicting tumor progression and targeting in anti-cancer strategies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Creatine Kinase / genetics*
  • Creatine Kinase / metabolism
  • DNA Methylation / genetics*
  • Female
  • Gene Expression Regulation, Neoplastic*
  • Humans
  • Male
  • Middle Aged
  • Neoplasm Invasiveness
  • Promoter Regions, Genetic
  • Proto-Oncogene Proteins c-myc / genetics
  • Proto-Oncogene Proteins c-myc / metabolism
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Stomach Neoplasms / enzymology
  • Stomach Neoplasms / genetics*
  • Stomach Neoplasms / pathology*
  • src-Family Kinases / genetics*
  • src-Family Kinases / metabolism

Substances

  • Proto-Oncogene Proteins c-myc
  • RNA, Messenger
  • lyn protein-tyrosine kinase
  • src-Family Kinases
  • Creatine Kinase

Grants and funding

This study was supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq; grants #471072/2012-5 and 402283/2013-9; fellowship to MCS and RRB), Fundação de Amparo à Pesquisa do Pará (FAPESPA; grant #ICAAF 123/2014 to RRB) and Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP; grant #2009/07145-9; fellowship to MFL) as grants and fellowship awards. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.