儿童急性淋巴细胞白血病6q16.3微卫星DNA缺失及生物信息学分析

Allelic loss of 6q16.3 microsatellite DNA in childhood acute lymphoblastic leukemia and bioinformatics analysis

目的定位儿童急性淋巴细胞白血病(ALL)杂合性缺失(LOH)的集中区域,探索新的肿瘤抑制基因。方法取6q16.3的15个微卫星标记,用聚合酶链反应-变性凝胶电泳-银染技术对165例 ALL 患儿等位基因 LOH 的情况进行生物信息学分析;同时分析其与临床预后因素的相关性。结果至少1个位点的 LOH 率为32.7%,D6S1709-D6S1028及 D6S2160-D6S1580是高频率集中缺失的区域,早期复发患儿的 LOH 率高于无早期复发患儿;谷氨酸受体6基因(GRIK2)可能为抑癌基因,2个区域存在可能代表新基因的表达序列标签12个。微卫星 LOH 与白细胞计数、病态细胞数、核型分析、早期复发均有相关性(P 值均<0.05)。结论 D6S1709-D6S1028和 D6S2160-D6S1580为目前国内外所确定的最精确缺失区,该区域可能存在1个或数个肿瘤抑制基因,6q16.3的 LOH 的发生与 ALL预后有一定关系。

Objective To locate the cluster region of loss of heterozygosity（LOH） in children with acute lymphoblastic leukemia （ALL） ,and explore the new tumor suppressor gene. Methods Allelic loss was analyzed by PCR with 15 microsatellite markers mapping on 6q16.3. The LOH was analyzed by bioinformatits. The relationship between LOH and clinical factors was further analyzed. Results The frequency of LOH at least at one loci on 6q16.3 was 32.7%. The LOH in relapsed patients was higher than those in not relapsed. The higher frequency of LOH was observed in two regions of D6S1709- D6S1028 and D6S2160- D6S1580 at 6q16.3. GRIK2 may be a candidate of tumor suppressor gene. There are 12 ESTs may carry out new antioncogene. Patients with 6q LOH had higher WBC counts （P 〈0.01 ） , blast cells percentage（P 〈 0.01）, relapse rate（P〈0.05） and chromosomal aberration（P〈0.05）. Conclusion D6S1709- D6S1028 and D6S2160- D6S1580 are two regions of minimus deletion on 6q16.3 in which tumor suppressor gene may exist. The LOH on 6q16.3 may be a prognostic index of children with ALL.