Aberrant methylation and simian virus 40 tag sequences in malignant mesothelioma.
Aberrant promoter methylation and resultant silencing of several genes plays an important role in the pathogenesis of many tumor types. We compared the methylation profile of 66 malignant mesotheliomas (MMs) and 40 lung adenocarcinomas using methylation-specific PCR for seven genes frequently methylated in lung cancer. We also compared the methylation frequencies of these genes as well as the methylation index, a reflection of all of the gene frequencies, with the presence of SV40 large T-antigen (Tag) sequences, histological subtype, and patient survival. Our major findings are: (a) with the exception of the RASSF1A promoter of the RASSF1 gene, frequencies of aberrant methylation were significantly lower in MMs than in adenocarcinomas; (b) the frequency of RASSF1A aberrant methylation and the value of the methylation index were significantly higher in SV40 sequence positive MM than in negative MM; and (c) the methylation index was higher in epithelial MM than in sarcomatous/mixed MM. Our results demonstrate a relationship between SV40 and aberrant methylation in MMs.
Toyooka
S
S
Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, 6000 Harry Hines Boulevard, Dallas, TX 75390, USA.
Pass
H I
HI
Shivapurkar
N
N
Fukuyama
Y
Y
Maruyama
R
R
Toyooka
K O
KO
Gilcrease
M
M
Farinas
A
A
Minna
J D
JD
Gazdar
A F
AF
D000230:Adenocarcinoma / Q000235:genetics / Q000473:pathology; D000328:Adult; D000368:Aged; D000952:Antigens, Polyomavirus Transforming / Q000235:genetics*; D019175:DNA Methylation; D005260:Female; D016147:Genes, Tumor Suppressor; D051549:Glutathione S-Transferase pi; D005982:Glutathione Transferase / Q000235:genetics; D006801:Humans; D007527:Isoenzymes / Q000235:genetics; D008175:Lung Neoplasms / Q000235:genetics / Q000473:pathology; D008297:Male; D008654:Mesothelioma / Q000235:genetics* / Q000473:pathology; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D014407:Tumor Cells, Cultured; D025521:Tumor Suppressor Proteins
D000952:Antigens, Polyomavirus Transforming; D007527:Isoenzymes; D009363:Neoplasm Proteins; C411762:RASSF1 protein, human; D025521:Tumor Suppressor Proteins; C496556:GSTP1 protein, human; D051549:Glutathione S-Transferase pi; D005982:Glutathione Transferase