Frequent hypermethylation of 5' flanking region of TIMP-2 gene in cervical cancer.
Tissue inhibitor of metalloproteinase-2 (TIMP-2) is an endogenous inhibitor of matrix metalloproteinases (MMPs). This multifunctional protein regulates activities of MMPs and possesses growth promoting effect in cell culture, anti-tumoral, anti-apoptotic and anti-angiogenic effects in animal model systems in vivo. It has been shown that this gene is downregulated in cervical carcinomas. The mechanism of inhibition of TIMP-2 expression remains obscure. We have examined whether aberrant DNA methylation of the 5'CpG island of the TIMP-2 gene is involved in its inhibition during cervical carcinogenesis. Bisulfite-modified DNA sequencing and MSP assay showed aberrant methylation of TIMP-2 5'-CpG island in 17 of 36 (47%) invasive cervical carcinomas and in 2 of 3 cervical cancer cell lines. TIMP-2 gene was mostly unmethylated in the morphologically normal tissues adjacent to the tumors, whereas methylated alleles of this gene were found in 4 samples. Each tumor and each cell line DNA was characterized by unique methylation pattern, however a discrete region of TIMP-2 CpG island upstream to the transcription start site was densely methylated in all hypermethylated DNA samples examined. The expression of TIMP-2 mRNA can be restored in the cell lines, in which this discrete region of TIMP-2 CpG island is methylated, by treatment with demethylating agents, 5-azacytidine and 5-aza-2'-deoxycytidine. Our data suggest that the aberrant methylation of TIMP-2 favors the development of primary cervical tumors. We describe for the first time the aberrant hypermethylation of TIMP-2 gene in human cancer.
Ivanova
Tatyana
T
N.N. Blochin Cancer Research Center, Russian Academy of Medical Sciences, Institute of Carcinogenesis, Kashirskoye shosse 24, Moscow 115-478, Russia.
Vinokurova
Svetlana
S
Petrenko
Anatolii
A
Eshilev
Ernest
E
Solovyova
Nina
N
Kisseljov
Fjodor
F
Kisseljova
Natalia
N
D000483:Alleles; D045744:Cell Line, Tumor; D018899:CpG Islands; D003596:Cytosine / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D019175:DNA Methylation; D005260:Female; D006367:HeLa Cells; D006801:Humans; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013447:Sulfites / Q000494:pharmacology; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000096:biosynthesis / Q000235:genetics*; D014158:Transcription, Genetic; D002583:Uterine Cervical Neoplasms / Q000235:genetics* / Q000378:metabolism
D012333:RNA, Messenger; D013447:Sulfites; D019716:Tissue Inhibitor of Metalloproteinase-2; D003596:Cytosine; D004247:DNA