The correlation between CpG methylation on promoter and protein expression of E-cadherin in oral squamous cell carcinoma.
BACKGROUND
Reduction of E-cadherin in most common epithelial tumors relates to metastasis, which results from the silence of E-cadherin by CpG methylation.


METHODS
We examined the E-cadherin expression by immunohistochemical staining and detected methylation by methylation-specific polymerase chain reaction (MSP) in 48 primary oral SCC tissues.


RESULTS
The results showed that 41 out of 48 (85.4%) cancerous tissues and 16 out of 48 (33.3%) nearby non-cancerous tissues had CpG methylation on the promoter region of E-cadherin. In these non-cancerous tissues, 2 out of 16 (12.5%) had no methylation change in their paired cancerous part. Immunohistochemical study showed that a decreased expression pattern was found in the tissue which had CpG methylation on the promoter region, but an over expression island or aberrant expression was also frequently found in these cases.


CONCLUSIONS
The methylation of E-cadherin in oral SCC may occur in the precancerous stage and the process is dynamic, which has no relationship with the aberrant expression of E-cadherin protein.
Yeh
Kun-Tu
KT
Departments of Molecular Medicine and Laboratory Medicine, China Medical College Hospital, Taichung, Taiwan.
Shih
Mu-Chin
MC
Lin
Ting Hsu
TH
Chen
Jui-Chang
JC
Chang
Jan-Yi
JY
Kao
Chi-Feng
CF
Lin
Keh-Liang
KL
Chang
Jan-Gowth
JG
D000328:Adult; D000368:Aged; D015820:Cadherins / Q000096:biosynthesis* / Q000235:genetics*; D002294:Carcinoma, Squamous Cell / Q000235:genetics* / Q000378:metabolism*; D018899:CpG Islands; D019175:DNA Methylation; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000235:genetics* / Q000378:metabolism*; D011401:Promoter Regions, Genetic
D015820:Cadherins