[High expression of DNMT1 was correlated with beta-catenin accumulation and malignant phynotype of lung squamous cell carcinoma and adenocarcinoma].
OBJECTIVE
DNA methyltransferase 1 (DNMT1) is one of the important molecules regulating DNA methylation. The abnormal expression of DNMT1 was associated with the methylation and inactivation of tumor suppressor gene and tumorigenesis. The aim of this study is to clarify the difference of DNMT1 expression between lung cancer tissues and corresponding normal lung tissues, to analyze the relationships between DNMT1 expression and clinicopathologic characteristics of lung squamous cell carcinoma and adenocarcinoma, and to investigate the correlation between the expressions of DNMT1 and beta-catenin.


METHODS
The expressions of DNMT1 and beta-catenin were examined in 84 lung squamous cell carcinoma and adenocarcinoma tissues and corresponding normal lung tissues using tissue microarray and immunohistochemistry.


RESULTS
The average positive rate of DNMT1 was significantly higher in 84 lung cancer tissues [(58.04+/-35.07)%] than that in corresponding normal lung tissues [(6.88+/-10.26)%](t=12.835, P<0.001). The high expression of DNMT1 was positively correlated with adenocarcinoma histological type (r=0.365, P=0.001), poor differentiation (r=0.253, P=0.021) and lymph node metastasis (r=0.246, P=0.024) in lung cancer. The expression of DNMT1 was significantly correlated with the cytoplasmic expression of beta-catenin (r=0.571, P<0.001).


CONCLUSIONS
The high expression of DNMT1 was a common phenomenon in lung squamous cell carcinoma and adenocarcinoma. The high expression of DNMT1 was correlated with the malignant phynotype of lung cancer. DNMT1 may express coordinately with beta-catenin in lung cancer.
Xu
Hongtao
H
Department of Pathology, College of Basic Medical Sciences, China Medical University, Shenyang 110001, China. xu.htao@yahoo.com.cn
Wang
Zuozhou
Z
Liu
Di
D
Li
Qingchang
Q
Dai
Shundong
S
Wang
Enhua
E
D000230:Adenocarcinoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000235:genetics* / Q000378:metabolism; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D055815:Young Adult; D051176:beta Catenin / Q000235:genetics* / Q000378:metabolism
D051176:beta Catenin; D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases; C000619380:DNMT1 protein, human