Quantification of caveolin isoforms using quantitative real-time RT-PCR, and analysis of promoter CpG methylation of caveolin-1alpha in human T cell leukemia cell lines.
Caveolin-1, an essential structural component of caveolae, functions as a negative regulator for signal transduction and has been suggested to be a candidate tumor suppressor. Lack of caveolin-1 expression has been implicated in the pathogenesis of oncogenic cell transformation and tumorigenesis in many cancers. On the other hand, over-expression has also been associated with tumor progression and metastasis in prostate cancers. Hence, alteration of caveolin-1 expression has been proposed as a clinical marker for diagnosis and prognosis in various cancers. For precise analyses of the caveolin expression in human T cell leukemia cell lines, we measured the mRNA levels of caveolin isoforms, caveolin-1alpha, -1beta, -2, and -3 with real-time RT-PCR using external standards for each isoform. In the panel of human T cell leukemia cell lines tested, four cell lines expressed caveolin-1alpha, -1beta and -2, but not -3, which was consistent with the protein levels. The expression profiles in most cell lines are caveolin-1alpha > caveolin-1beta > caveolin-2. Two cell lines did not express either of the caveolin mRNAs. Methylation analyses for the CpG sites in the promoter region of a positive and a negative cell line did not show a clear correlation with the expression status, suggesting that mechanisms other than CpG methylation are involved in the regulation of caveolin-1alpha expression in human T cell leukemia cell lines.
Tsuji
Yuichiro
Y
Department of Otolaryngology, Osaka Medical College, Daigakumachi Takatsuki 569-8686, Japan.
Nakagawa
Toshimasa
T
Hatanaka
Michiyo
M
Takeuchi
Tohru
T
Matsumoto
Eriko
E
Takenaka
Hiroshi
H
Shimizu
Akira
A
D051242:Caveolin 1 / Q000235:genetics* / Q000378:metabolism; D051243:Caveolin 2 / Q000378:metabolism; D051244:Caveolin 3 / Q000378:metabolism; D022461:Caveolins / Q000378:metabolism*; D018899:CpG Islands / Q000235:genetics*; D019175:DNA Methylation; D020869:Gene Expression Profiling; D006801:Humans; D015458:Leukemia, T-Cell / Q000235:genetics*; D011401:Promoter Regions, Genetic; D020033:Protein Isoforms / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods*; D014407:Tumor Cells, Cultured
C495540:CAV1 protein, human; C495544:CAV2 protein, human; D051242:Caveolin 1; D051243:Caveolin 2; D051244:Caveolin 3; D022461:Caveolins; D020033:Protein Isoforms; D012333:RNA, Messenger