Molecular cloning and expression of proto-oncogene FRAT1 in human cancer.
FRAT1 and FRAT2 genes, clustered in human chromosome 10q24, are human homologues to mouse proto-oncogene Frat1, which promotes carcinogenesis through activation of the WNT - beta-catenin - TCF signaling pathway. FRAT1 and FRAT2 mRNAs are up-regulated together in a gastric cancer cell line TMK1, and also in 2 out of 10 cases of primary gastric cancer. Here, we isolated FRAT1 cDNA (AB074890), which showed two amino-acid substitutions (Gln57X and His58Asp) compared with human FRAT1 cDNA previously reported by another group (U58975). The Gln57-His58 FRAT1 allele isolated in this study was also identified in human genome draft sequences. FRAT1 mRNA was almost ubiquitously expressed in human pancreatic cancer cell lines. Expression level of FRAT1 mRNA was relatively higher in esophageal cancer cell lines TE2, TE3, TE4, a cervical cancer cell line SKG-IIIa, and breast cancer cell lines MCF-7 and T-47D. Expression level of FRAT1 mRNA was not significantly changed after all-trans retinoic-acid treatment in NT2 cells with the potential of neuronal differentiation. Expression of FRAT1 mRNA in MCF-7 cells derived from breast cancer was down-regulated by beta-estradiol. This is the first report on isolation of FRAT1 cDNA derived from the more common FRAT1 allele, and also on regulation of FRAT1 mRNA in human cancer cells.
Saitoh
Tetsuroh
T
Genetics and Cell Biology Section, Genetics Division, National Cancer Center Research Institute, Tokyo 104-0045, Japan.
Mine
Tetsuya
T
Katoh
Masaru
M
D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D002352:Carrier Proteins; D003001:Cloning, Molecular; D017931:DNA Primers / Q000737:chemistry; D015536:Down-Regulation; D005260:Female; D015870:Gene Expression; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008969:Molecular Sequence Data; D009154:Mutation; D009363:Neoplasm Proteins; D009369:Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism*; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D012334:RNA, Neoplasm / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000378:metabolism
D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D017931:DNA Primers; C491819:FRAT1 protein, human; C491818:Frat1 protein, mouse; D047908:Intracellular Signaling Peptides and Proteins; C000715470:MAS1 protein, human; D009363:Neoplasm Proteins; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm