Increased expression of deoxyribonucleic acid methyltransferase gene in human astrocytic tumors.
The relationship between the grade of astrocytic tumor and the expression of deoxyribonucleic acid methyltransferase (DNA-MTase) gene was examined. The levels of DNA-MTase messenger ribonucleic acid (mRNA) were measured by semiquantitative reverse transcriptase-polymerase chain reaction in surgical specimens from 12 astrocytic tumors (4 astrocytomas, 6 anaplastic astrocytomas, and 2 glioblastomas) and two normal brain tissues, and in four glioma cell lines. Compared to normal brain tissues, the levels of DNA-MTase mRNA were increased by 16- to 55-fold in low grade astrocytomas, and significantly increased by 200- to 4500-fold in high grade astrocytomas (anaplastic astrocytomas and glioblastomas) and more than 4500-fold in glioma cell lines. In situ hybridization with paraffin-embedded surgical specimens of human astrocytic tumors showed DNA-MTase mRNA was abundantly expressed in high grade astrocytomas. The detection of increased DNA-MTase expression in astrocytic tumor indicates involvement in the tumorigenesis and suggests that blocking of this change with specific inhibitors may offer new therapeutic strategies for malignant astrocytic tumors.
Okada
Y
Y
Department of neurosurgery, Kanazawa University School of Medicine, Japan.
Okada
T
T
Numata
M
M
Hayashi
Y
Y
Yamashima
T
T
Yamashita
J
J
D001254:Astrocytoma / Q000235:genetics*; D015139:Blotting, Southern; D001932:Brain Neoplasms / Q000235:genetics*; D004273:DNA, Neoplasm / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic; D005909:Glioblastoma / Q000235:genetics; D006801:Humans; D017403:In Situ Hybridization; D066298:In Vitro Techniques; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured; D012359:tRNA Methyltransferases / Q000235:genetics*
D004273:DNA, Neoplasm; D012359:tRNA Methyltransferases