1994 Fiscal Year Final Research Report Summary
Molecular Biology of Glucose Transporter expressed in Brain Tumors
| Project/Area Number |
04454366
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Cerebral neurosurgery
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| Research Institution | Kyorin Univ. |
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Principal Investigator |
NAGAMATSU Shinya Kyorin Univ. Scho. of Med., Biochem., Associate Professor, 医学部, 助教授 (80231489)
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| Co-Investigator(Kenkyū-buntansha) |
SAWA Hiroki Kyorin Univ. Scho. of Med., Neurosurgery, Assistant Professor, 医学部, 講師 (80135912)
HOSHINO Takao Kyorin Univ. Scho. of Med., Neurosurgery, Professor (90010165)
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| Project Period (FY) |
1992 – 1994
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| Keywords | Brain tumor / glucose transporter / GLUT / PCR / cDNA cloning / Northern blot |
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| Research Abstract |
There may be a close relationship between the growth rate of brain tumor and glucose metabolism, as clinical studies with positron emission tomography (PET) have demonstrated that cerebral metabolic ultilization of glucose is increased in brain tumors. Since the glucose is transported into the cell through a facilitated diffusion process, mediated by glucose transporter carrier protein (GLUT), GLUT must play an inportant role in glucose metabolism of a brain tumor. First of all, we have examined the expression of glucose transporter isoforms in human astrocytic tumors, and compared the levels of GLUT mRNA and protein with the histological grading of astrocytic tumor. Human astrocytic tumors expressed the mRNAs and proteins of GLUT1, GLUT3, and GLUT4. Among them, GLUT3 was the major isoform expressed in brain tumors. There was no correlation between the histological grading of human astrocytic tumor cells and the expression levels of glucose transporter. Second, we determined the relationship between the growth rate of C6 rat glioma cells, the glucose transport system, and glucose metabolism. Rat C6 glioma cells were subcloned to 4 different cell lines (CL1-CL4), where CL1 is growing slowly, and CL4 is rapidly growing. The levels of GLUT and uptake of glucose were markedly increased in CL4 compared to in CL1. Further, the concentrations of intracellular glucose and ATP also demonstrated the increased rate of glucose metabolism in the rapidly growing cells (CL4). These results suggest that the facilitative glucose transporter (GLUT) may be altered in astrocytic tumor cells and the growth rate of glioma cells is closely related to the glucose transport and glucose metabolism.
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