Mutant type glutathione S-transferase theta 1 gene homologue to mTOR in myelodysplastic syndrome: possible clinical application of rapamycin.
In this study, we observed the expression of the GSTT-1 gene in patients with myelodysplastic syndrome (MDS) at the messenger RNA level. Reverse transcription-polymerase chain reaction (RT-PCR) for GSTT-1 was performed with a pair of primers complementary to the 5' coding section and the 3' coding section of the GSTT-1 cDNA for amplifying the 623-bp band. Among 20 patients with MDS, 8 patients showed the expected 623-bp band on RT-PCR, and 12 patients showed a 500-bp band on RT-PCR, indicating that a 123-bp sequence was deleted as a mutant of the GSTT-1 gene. Furthermore, a BLAST DNA search showed that the deletion of a 123 bp sequence creates a sequence that is 63% homologous to human FKBP-rapamycin associated protein (FRAP); this protein has been termed a mammalian target of rapamycin (mTOR). We respectively transfected the wild type and the mutant type GSTT-1 gene in an expression vector to two cell lines (K562 and HL-60). The stable transformants for the wild type and the mutant type GSTT-1 genes were made by G418 selection. Interestingly, rapamycin could induce significant growth inhibition of the stable transformants for mutant type GSTT-1, which was indicative of apoptosis, but not that of those for wild type GSTT-1. These results suggest that rapamycin could be included in the therapeutic modality for the patients with MDS who have the mTOR sequences in GSTT-1 gene.
Maeda
Yasuhiro
Y
Department of Hematology, Nephrology and Rheumatology, Kinki University School of Medicine, 377-2, Ohno-Higashi, Osaka-Sayama, Osaka 589-8511, Japan. ymaeda@med.kindai.ac.jp
Yamaguchi
Terufumi
T
Ueda
Satomi
S
Matsuo
Koki
K
Morita
Yasuyoshi
Y
Naiki
Yoshito
Y
Miyazato
Hajime
H
Shimada
Takahiro
T
Miyatake
Jun-Ichi
J
Matsuda
Mitsuhiro
M
Kanamaru
Akihisa
A
D017304:Annexin A5 / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects; D001483:Base Sequence; D002455:Cell Division / Q000187:drug effects; D017931:DNA Primers; D017353:Gene Deletion; D005982:Glutathione Transferase / Q000235:genetics*; D018922:HL-60 Cells; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D020014:K562 Cells; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D009190:Myelodysplastic Syndromes / Q000188:drug therapy* / Q000201:enzymology*; D011494:Protein Kinases / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism; D012334:RNA, Neoplasm / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D020123:Sirolimus / Q000627:therapeutic use*; D058570:TOR Serine-Threonine Kinases; D022021:Tacrolimus Binding Proteins / Q000378:metabolism; D014162:Transfection
D017304:Annexin A5; D017931:DNA Primers; D007166:Immunosuppressive Agents; D012333:RNA, Messenger; D012334:RNA, Neoplasm; C413545:glutathione S-transferase T1; D005982:Glutathione Transferase; D011494:Protein Kinases; C546842:MTOR protein, human; D058570:TOR Serine-Threonine Kinases; D022021:Tacrolimus Binding Proteins; D020123:Sirolimus