5-Aza inhibits cell migration and methylation of CDH1 gene in tongue squamous cell carcinomacell lines

Abstract

Objective To evaluate the effect of 5-Aza on methylation of CDH1 and the migration and mobility of tongue squamous cell carcinoma (TSCC) cell lines. Methods Two TSCC cell lines UM1, UM2 were treated with or without 5-Aza. Cell morphology and growth patterns were observed under the light microscope. Wound healing and transwell assay were performed to determine the ability of cell migration. Western blot and immunofluorescence were used to detect the expression of E-cadherin. Methylation specific polymerase chain reaction (MSP) was used to determine the methylated profile of CDH1. Chi-square test was performed to compare relative invasion rate and the significance level was set at P<0.05. Results UM1 cells appeared to be dispersed, spindle-shaped with migratory protrusions, whereas, UM2 cells presented with cobblestone-like pattern and an apical-basal polarity. A higher expression of E-cadherin with lower mobility was demonstrated in UM2 than in UM1. The wound area was completely covered in UM1 after 48 h, while less than 75% in UM2. UM1 displayed a higher methylation profile in the MSP detection. After treated with 5-Aza in UM1 cells, the cell morphology became irregular and UM2-like with firm cell connection. The 48 h wound cover area of 5-Aza treated UM1 was less than 70%, the relative invasion rate was 102% (χ2 = 0.651, P>0.05) compared to the untreated cells and E-cadherin expression was increased, while a demethylation of CDH1 gene was observed. Conclusion Demethylation of CDH1 was involved in 5-Aza mediated inhibition of cell migration and motility in TSCC cells. Key words: Tongue; Carcinoma, squamous cell; Migration; Methylation; E-cadherin; Epithelial-mesenchymal transition