[Methylation and expression of glioma pathogenesis-related protein 1 gene in acute myeloid leukemia].

OBJECTIVE: To detect the methylation and expression of glioma pathogenesis-related protein 1(GLIPR1) gene in the acute myeloid leukemia (AML) cell lines and bone marrow cells from AML patients, and to determine the relationship between promoter methylation and expression of GLIPR1.
METHODS: Five leukemia cell lines, 54 bone marrows from the newly diagnosed AML patients, 48 bone marrows from the acute lymphoblastic leukemia (ALL )patients, 40 bone marrows from the chronic myeloid leukemia (CML) patients,35 bone marrows from control patients, and 8 bone marrows from the complete remission AML patients were collected. RT-PCR and methylation-PCR (MSP) were used to detect the mRNA expression and promoter methylation of GLIPR1, respectively, and the relationship between them was analyzed.
RESULTS: The level of GLIPR1 mRNA in the AML cell lines was lower than that in the chronic myeloid leukemia (CML) and ALL cell lines, whereas the methylation level of GLIPR1 in the former was higher than that in the latter. The level of GLIPR1 mRNA in the AML cell lines was significantly increased, but had no obvious changes in the CML and ALL cell lines after 5-aza-2dC treatment. The mRNA level of GLIPR1 in the AML bone marrows (0.38+/-0.20)was obviously lower than that in the ALL bone marrows (0.76+/-0.18), CML bone marrows (0.80+/-0.14), and control bone marrows(0.85+/-0.12). The level of GLIPR1 mRNA in the bone marrows with complete remission AML was obviously higher than that in the AML bone marrows before the treatment (0.78+/-0.13 vs. 0.36+/-0.20); but there was no obvious difference between the ALL bone marrows and the control bone marrows, and the CML bone marrows and the control bone marrows (both P>0.05). The positive rate of GLIPR1 gene methylation in the AML bone marrows (81.5%) was obviously higher than that in the ALL bone marrows(37.5%), CML bone marrows (27.5%) and the control bone marrows(14.3%). The positive rate of GLIPR1 gene in the bone marrows with complete remission AML was obviously lower than that in the bone marrows before the treatment (12.5% vs. 75.0%), but there was no obvious difference between the ALL bone marrows and between the control bone marrows,and the CML bone marrows and the control bone marrows (both P>0.05). There was a negative correlation between the mRNA level and methylation status of GLIPR1 in the AML bone marrows.
CONCLUSION: GLIPR1 expression is downregulated or even lost by promoter methylation in AML, and the expression and methylation level of GLIPR1 gene may have some significance in evaluating the curative effect of AML patients.