| Project/Area Number |
01570183
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Experimental pathology
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| Research Institution | Hokkaido University |
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Principal Investigator |
OIKAWA Tsuneyuki Hokkaido Univ School of Med. Lecturer, 医学部, 講師 (80150241)
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| Project Period (FY) |
1989 – 1990
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| Project Status |
Completed (Fiscal Year 1990)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1990: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1989: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | Mouse plasmacytoma / Rearranged c-myc / Tissue-specificity / Hybrid cells / DNase I sensitivity / DNase I感受性 / がん / c-myc / 遺伝子発現 |
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| Research Abstract |
We have reported that high expression of the rearranged c-myc in mouse plasmacytoma cells is suppressed after cell fusion with fibroblastic cells. In this study, we analyzed molecular mechanism of this suppression. The suppression of the rearranged c-myc expression was also found in hybrids between plasmacytoma and T-cell lymphoma or teratocarcinoma. No involvement of DNA methylation of the rearranged c-myc in the suppression was suggested by comparing the methylation patterns in the parental and hybrid cells. Expression of the non-rearranged c-myc was enhanced by treatment of the hybrid cells with cycloheximide, while that of the rearranged c-myc was still undetectable. Run-on assay demonstrated that suppression of the rearranged c-myc expression of the rearranged c-myc expression was at transcriptional level, which was parallel to DNase I sensitivity of the gene ; higher DNase I sensitivity of the rearranged c-myc in plasmacytoma was reduced after cell fusion with fibroblastic cells. We attempted to transfer nuclear proteins from fibroblasts into plasmacytoma cells by using the rbc-ghost method, but we failed to suppress the rearranged c-myc by this method. Recently it has been reported that there is a B-cell specific enhancer containing octamer motif in 3' end of the immunoglobulin C gene. Expression of B-cell-specific Oct-2 gene is responsible for suppression of the rearranged c-myc in hybrids between plasmacytoma and non-B cells.
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