ABSTRACT
Background and purpose: As one of the important epigenetic phenomena, DNA methylation plays an important regulatory function for the expression of genes. Study shows that abnormal changes of DNA methy-lation patterns of normal tumor cell genome leads to dysfunction of cancer related gene, and this may be associated with tumor occurrence and development. The study investigated the promoter methylation and expression of caveolin-1 (CAV-1) gene in esophageal squamous cell carcinoma (ESCC), and to elucidate its role in ESCC. Methods:We used MSP approach, RT-PCR, and immunohistochemistry method respectively to examine the methylation status of the 5’CpG island of CAV-1 gene and its expression at mRNA and protein levels in tumors and corresponding normal tissues. Results: CAV-1 mRNA expression in tumor tissues (0.86±0.56) was signiifcantly higher than that in corresponding normal tissues (0.40±0.36, P0.05). The promoter methylation frequency of CAV-1 in tumor specimens was 2.0%(1/51), and the methylation phenomenon has not been found in corresponding normal tissues. The promoter methylation fre-quency of CAV-1 in tumor specimens showed no signiifcant difference compared with the corresponding normal tissues (P>0.05). Conclusion:The mRNA and protein expression of CAV-1 in tumor specimens was signiifcantly higher than that in corresponding normal tissues. Aberrant high expression of CAV-1 has played a certain role in promoting tumori-genesis and lymph node metastasis. The expression both in ESCC and corresponding normal tissues has no correlation with the promoter methylation status.
ABSTRACT
Background and purpose:RASSF10 acts as a kind of tumor suppressor in various tumor tissues, but researches in cardiac adenocarcinoma has not been reported. This study aimed to detect the methylation status and expression ofRas-association domain family 10 (RASSF10) in gastric cardia adenocarcinoma (GCA), and explore its role in occurrence and development of GCA.Methods:Methylation speciifc polymerase chain reaction (MSP), reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry method were respectively used to detect methylation status, mRNA expression and protein expression ofRASSF10 in 81 GCA tissues and corresponding normal tissues.Results:The promoter methylation frequency ofRASSF10 in GCA tissues (64.20%, 52/81) was signiifcantly higher than that in corresponding normal tissues (20.99%, 17/81,P<0.05), and was closely correlated with TNM stages, differential degree and lymph node metastasis (P<0.05). RASSF10 mRNA expression in GCA tissues (0.57±0.05) was significantly lower than that in corresponding normal tissues (0.78±0.02,P<0.05), and was closely correlated with TNM stages and lymph node metastasis (P<0.05). Protein expression of RASSF10 in GCA tissues (31.10%, 26/81) was signiifcantly lower than that in corresponding normal tissues (71.60%, 58/81,P<0.05), and was closely correlated with TNM stages, differential degree and lymph node metastasis (P<0.05). The promoter methylation frequency ofRASSF10 in GCA tissues was inversely related to its protein expression.Conclusion:Inactivation of RASSF10 caused by aberrantmethylation in the promoter region may be closely correlated with the GCA tumorgenesis.