Methylation of TMEFF2 Gene in Tissue and Serum DNA from Patients with Non-Small Cell Lung Cancer

Abstract

Lung cancer remains a global health problem with a high mortality rate. CpG island methylation is a common aberration frequently associated with gene silencing in multiple tumor types, emerging as a highly promising biomarker. The transmembrane protein with a single EGF-like and two follistatin domains (TMEFF2) is epigenetically silenced in numerous tumor types, suggesting a potential role as a potential tumor suppressor. However, the role of TMEFF2 in lung cancer remains to be fully elucidated. We explored the methylation status of TMEFF2 gene in 139 patients with non-small cell lung cancer (NSCLC) and the feasibility of detecting circulating methylated DNA as a screening tool for NSCLC using methylation-specific PCR in 316 patients and 50 age-matched health controls. TMEFF2 methylation in tumor tissues was found in 73 of the 139 NSCLCs (52.5%) and was related to gene expression. The frequency of TMEFF2 methylation was higher in females and never-smokers than in males and smokers with borderline significance (65.8% vs 47.8%, p = 0.06; 65.7% vs 48.1%, p = 0.07). Notably, in adenocarcinomas, TMEFF2 methylation was significantly more frequent in tumors without EGFR mutation than those with EGFR mutation (adjusted odds ratio = 7.13, 95% confidence interval = 2.05-24.83, P = 0.002). Furthermore, TMEFF2 methylation was exclusively detected in the serum of NSCLC patients at a frequency of 9.2% (29/316). These findings suggest that methylation-associated down-regulation of TMEFF2 gene may be involved in lung tumorigenesis and TMEFF2 methylation can serve as a specific blood-based biomarker for NSCLC.

EGFR mutational status in a large series of Caucasian European NSCLC patients: data from daily practice

“…It was hypothesised that different molecular mechanisms are active in tumours of smokers and non-smokers (An et al , 2012; Lee et al , 2012; Paik et al , 2012). Although tumours of smokers frequently exhibit KRAS mutations (a downstream effector in the EGFR pathway; Riely et al , 2009), in non-smokers the EGFR itself can be found mutated in many cases (Pham et al , 2006).…”

Cell-free circulating tumor DNA in plasma/serum of non-small cell lung cancer

“…Methylation-specific PCR techniques have been employed by most of the studies to quantify the methylation statues of genes ( Table 4). The genomic DNA was treated with bisulphite (a critical step in methylation analysis) in all studies in order to convert unmethylated cytosines of CpG dinucleotides into uracil or UpG [47,75,82]. In the past, researchers had to collect relatively large amounts of clinical samples to avoid DNA degradation during bisulfite treatment, but now, some commercial kits have been developed successfully which enable highly efficient bisulfite conversion, even the amount of starting material is limited.…”

The Clinical Utilization of Circulating Cell Free DNA (CCFDNA) in Blood of Cancer Patients

“…Complete or partial post treatment response to chemotherapy also correlates with no mutation detection compared to the pretreatment period. [18,36,184–187]. Evaluating methylation status of 14-3-3 sigma of serum DNA in pretreatment condition and for P16M in pleural lavage are considered for survival.…”