RNAM EXPRESSION AND DNA METHYLATION OF DKK2 GENE IN COLORECTAL CÂNCER.

BACKGROUND: Colorectal cancer is the third most common neoplasm in the world. Methylation of tumor related genes in CpG islands can cause gene silencing and been involved in the development of cancer. The potential role of DKK2 as a biomarker for early diagnosis of colorectal cancer remains unclear. OBJECTIVE: The aim of the study was to evaluate the profile of methylation and RNAm expression of DKK2 as potential predictors of colorectal cancer diagnosis and prognosis. METHODS: Expression of mRNAs encoding DKK2 in 35 colorectal cancer tissues was quantified using real-time polymerase chain reaction analysis. The DNA methylation was studied by high resolution melting analysis. The general characteristics of the patients were collected. DKK2 methylation and expression were compared to clinical, pathological aspects and overall survival. RESULTS: Among the 35 patients studied, 18 were male, 10 were on right colon and 25 on left colon. Among the 20 patients with high hypermethylation, 15 of them had mRNA low expression of DKK2. There was no significant association between DKK2 promoter methylation and mRNA DKK2 expression and clinical or pathological features. DKK2 promoter methylation (P=0.154) and DKK2 RNA expression (P=0.345) did not show significant correlation with overall survival. CONCLUSION: DKK2 promoter methylation and DKK2 RNA status appear to be biomarkers of cancer diagnosis but not predictors of prognosis.