ALL患儿肿瘤细胞的门冬酰胺合成酶活性研究

目的：不同类型急性淋巴细胞性白血病(ALL)对左旋门冬酰胺酶(LAsp)敏感度不完全相同,由于LAsp活性水平与细胞内门冬酰胺合成酶活性负相关,因此研究不同类型ALL患儿白血病细胞内门冬酰胺合成酶活性水平分布情况,有助于临床治疗中合理使用LAsp。方法：通过HPLCFLD及蛋白定量等技术,检测28例ALL患儿(免疫酶型TALL7例,B细胞系列ALL21例)白血病细胞内门冬酰胺合成酶活性水平。结果：TALL患儿肿瘤细胞内AS活性水平较B细胞系列ALL患儿的显著增高(P<0.05),其中TALL患儿肿瘤细胞内AS活性中位水平为每小时9.3nMAsn/mgprotein,B细胞系列ALL患儿为每小时5.2nMAsn/mgprotein。但无论是在B细胞系列ALL患儿还是在TALL患儿中,肿瘤细胞内AS活性存在多态性分布。结论：ALL患儿白血病细胞中门冬酰胺合成酶活性存在多态性分布,总体上TALL比B系ALL白血病细胞中门冬酰胺合成酶活性高。

Asparagine synthetase activity in pediatric acute lymphoblastic leukemia

Objective To study the cellular activity of asparagine synthetase in different types of childhood acute lymphoblastic leukemia (ALL). Methods The cellular activity of asparagine synthetase was detected by HPLC-FLD and Protein measurement in 28 ALL children (7 cases of T-ALL and 21 cases of B-lymphoid lineage ALL) before chemotherapy. Results The asparagines synthetase activity levels in T-ALL children were significantly higher than those of the B-lymphoid lineage ALL patients, with the median activity level of 9.3 nM Asn/mg protein/hr vs 5.2 nM Asn/mg protein/hr (P<0.05). The distribution of the asparagine synthetase activity demonstrated a polymorphism in either T-ALL or B-lymphoid lineage ALL patients. Conclusions The cellular activity of asparagines synthetase in ALL patients is presented with a polymorphism distribution. The asparagines synthetase activity levels in T-ALL are significantly higher than in B-lymphoid lineage ALL.