Department of Biochemistry and Molecular Biology, Medical School of Soochow University, Suzhou 215123, China.
Mol Cell Biochem. 2011 Dec;358(1-2):131-9. doi: 10.1007/s11010-011-0928-9. Epub 2011 Jul 1.
The expressions of β1,3-N-acetylglucosamonyltransferase-2 and -8 (β3GnT-2, β3GnT-8),-the two main glycosyltransferases responsible for the synthesis of poly-N-acetyllactosamine (polyLacNAc) in glycans, and β3GnT-5 participating in the syntheses of sphingoglycolipids were studied in leukemia cell lines during differentiation using RT-PCR method. β3GnT-2 and β3GnT-8 distribute widely in six myeloid and monocytoid leukemia cell lines with different abundances, while β3GnT-4 was only present in NB4 cells. ATRA (all-trans retinoic acid) and dimethylsulfoxide (DMSO), which induce the differentiation of HL-60 and NB4 (two human acute myeloid leukemia cell lines) to myelocytic lineage, up-regulated these two enzymes with various degrees at 2 and 72 h of treatment. In HL-60 cells treated with ATRA, the increase of β3GnT-8 was more than β3GnT-2, while in NB4 cells treated with DMSO, the increase of β3GnT-2 was more than β3GnT-8. However, when HL-60 and NB4 were differentiated to monocytic lineage induced by phorbol 12-myristate 13-acetate the expressions of β3GnT-2 and β3GnT-8 showed no alterations or the increase of expressions was far less than those in myelocytic differentiation. By means of FITC-labeled tomato lectin affinity staining and flow-cytometry, it was found that the product of β3GnT-2 and -8, polyLacNAc was also increased on the cell surface of HL-60 and NB4 treated with ATRA or DMSO, but unchanged when treated with PMA. These results were in accordance with the up-regulation of the mRNAs of β3GnT-2 and -8. The expression of β3GnT-5, however, was not changed both in myelocytic and monocytic differentiations. The difference in the up-regulation of β3GnT-2 and -8, especially their products may become a useful index to discriminate the myelocytic and monocytic differentiation of leukemia cells.
使用 RT-PCR 方法研究了白血病细胞系分化过程中两种主要的糖基转移酶 β1,3-N-乙酰氨基葡萄糖基转移酶-2 和 -8（β3GnT-2、β3GnT-8）和参与神经酰胺合成的 β3GnT-5 的表达。β3GnT-2 和 β3GnT-8 在六种髓系和单核白血病细胞系中广泛分布，丰度不同，而 β3GnT-4 仅存在于 NB4 细胞中。全反式视黄酸（ATRA）和二甲基亚砜（DMSO）可诱导 HL-60 和 NB4（两种人急性髓系白血病细胞系）向粒细胞分化，在处理的 2 和 72 小时内，这些酶的表达被不同程度地上调。在 ATRA 处理的 HL-60 细胞中，β3GnT-8 的增加大于β3GnT-2，而在 DMSO 处理的 NB4 细胞中，β3GnT-2 的增加大于β3GnT-8。然而，当 HL-60 和 NB4 被佛波醇 12-肉豆蔻酸 13-乙酸诱导分化为单核细胞系时，β3GnT-2 和 β3GnT-8 的表达没有改变，或者表达的增加远低于粒细胞分化。通过 FITC 标记的番茄凝集素亲和染色和流式细胞术发现，ATRA 或 DMSO 处理的 HL-60 和 NB4 细胞表面上的β3GnT-2 和 -8 的产物多乳糖胺也增加，但 PMA 处理时不变。这些结果与β3GnT-2 和 -8 的 mRNA 上调一致。β3GnT-5 的表达在粒细胞和单核细胞分化中均未改变。β3GnT-2 和 -8 的上调差异，特别是它们的产物可能成为区分白血病细胞粒细胞和单核细胞分化的有用指标。
