Effects of DACT1 methylation status on invasion and metastasis of nasopharyngeal carcinoma

BACKGROUND: The purpose of the present study was to investigate the role of the methylation status of the DACT1 gene on the invasion and metastasis of nasopharyngeal carcinoma cells. METHODS: The levels of methylation and expression of the DACT1 gene in nasopharyngeal carcinoma tissues and CNE2 cells were determined by methylation-specific PCR and RT-PCR, respectively. CNE2 cells were treated with 5-aza-2-deoxycytidine, and the variation in the methylation status of the DACT1 gene was detected, as well as the influence of methylation on invasiveness of nasopharyngeal carcinoma cells. RESULTS: The DACT1 gene was hyper-methylated in 44 of 62 cases of nasopharyngeal carcinoma. The DACT1 gene was hyper-methylated in 32 of 38 cases of nasopharyngeal carcinoma with lymph node metastasis, and the DACT1 gene was hyper-methylated in 7 of 24 cases of nasopharyngeal carcinoma without lymph node metastasis. The DACT1 mRNA level was weakly expressed or not expressed in all nasopharyngeal carcinoma tissues with hyper-methylated DACT1 genes; however, the DACT1 mRNA level was highly expressed in nasopharyngeal carcinoma tissues with low expression of the methylated DACT1 gene. The DACT1 gene was hyper-methylated and not expressed in CNE2 cells that did not have 5-aza-2-deoxycytidine treatment. After 5-aza-2-deoxycytidine treatment, the DACT1 gene was demethylated and the expression of DACT1 was restored. Moreover, the invasion ability was inhibited in CNE2 cells treated with 5-aza-2-deoxycytidine. CONCLUSION: The expression of DACT1 was related to the methylation status. High expression of DACT1 may inhibit the invasion and metastasis of nasopharyngeal carcinoma cells.

Mutation analysis on DACT1 gene in children with neural tube defects in northern Chinese Han population / 天津医药

Objective To investigate the correlation between neural tube defects (NTDs) and DACT1 gene, and provide the basic data for disease diagnosis and genetic counseling. Methods Blood samples were obtained from 163 NTDs patients and 480 unrelated healthy individuals. Mutation detection of DACT1 gene and DNA direct sequencing was carried out by PCR amplification. Bioinformatics analysis of these mutated loci was performed. Results Six mutations were found in NTDs patients, including 4 missense mutations (p.R45W, p.D142G, p.N356K and p.V702G). But these mutations were not found in 480 healthy individuals. Three mutated amino acid residues (p.45R, p.142D and p.356N) were highly conservative in evolution, and the mutated carriers were female patients, and suffered from anencephaly. Conclusion DACT1 gene mutation may be a risk factor of NTDs in Han population of northern China.