Promoter methylation of Wnt/β-Catenin signal inhibitor TMEM88 is associated with unfavorable prognosis of nonsmall cell lung cancer

Objective: Recent research has indicated that altered promoter methylation of oncogenes and tumor suppressor genes is animportant mechanism in lung cancer development and progression. In this study, we investigated the association between promoter methylation of TMEM88, a possible inhibitor of the Wnt/β-Catenin signaling, and the survival of patients with non-small cell lung cancer (NSCLC). Methods: Twelve pairs of tumor and adjacent non-tumor samples were used for microarray analyses of DNA methylation andgene expression. For validation, more than two hundred additional samples were analyzed for methylation using bisulfitepyrosequencing and for gene expression using qRT-PCR. Then the cell function were tested by wound healing, transwell, CCK8and cell cycle assay. Results: Our analysis of patient specimens showed that TMEM88 methylation was higher in NSCLC tumors (82.2% ± 10.3, P 56 months;P=0.021). In addition, we found that demethylation treatment could inhibit tumor cell proliferation, migration, and invasion,which was supportive of an association between methylation and survival. Conclusions: Based on these consistent observations, we concluded that TMEM88 may play an important role in NSCLC progression and that promoter methylation of TMEM88 may serve as a biomarker for NSCLC prognosis and treatment.