新疆地区维吾尔族、汉族非小细胞肺癌患者胞苷脱氨酶基因多态性对比分析

目的分析新疆地区维吾尔族、汉族非小细胞肺癌(NSCLC)患者胞苷脱氨酶(CDA)基因多态性。方法收集晚期NSCLC初治患者120例,其中维吾尔族53例(维族组)、汉族67例(汉族组),采用直接测序的方法检测两组CDA A79C、G208A基因多态性。结果两组CDA A79C、G208A基因型频率均符合Hardy-Weinberg平衡(P均>0.05)。维族组A79C AA、AC、CC基因型频率及A、C等位基因频率分别为75.4%、18.9%、5.7%、84.9%、5.1%,汉族组分别为52.2%、29.9%、17.9%、67.2%、32.8%,两组比较,P均<0.05;维族组G208A GG、GA基因型频率和G、A等位基因频率分别为94.3%、5.7%、97.2%、2.8%,汉族组分别为77.6%、22.4%、88.8%、11.2%,两组比较,P均<0.05。结论新疆地区维吾尔族、汉族CDA A79C、G208A这两个位点的基因多态性存在种族差异性。

胞苷脱氨酶基因对小鼠大剂量化疗的保护作用

目的:将人胞苷脱氨基酶基因(CD)导入小鼠骨髓细胞后,观察小鼠对大剂量阿糖胞苷(Ara—C)的耐受性,探讨骨髓耐受联合化疗的可行性. 方法:以反转录病毒为载体,将人胞苷脱氨基酶基因(CD)通过共培养转染入小鼠骨髓干细胞,观察共培养后的骨髓细胞及受体小鼠骨髓移植后经药物处理后的骨髓细胞耐Ara—C CFU—GM生成情况;从转基因小鼠骨髓细胞提取DNA,用PCR检测转基因小鼠骨髓细胞耐药基因的表达;观察转基因小鼠经大剂量Ara—C化疗后血象、体质量及生存率的变化. 结果:骨髓移植前共培养后供体的骨髓细胞和骨髓移植后受体含有耐药基因(SFG—CD)的骨髓细胞均有耐药克隆的形成(52%,54%;与对照组相比X2分别为124.62, 126.26,P均<0.01),并明显增加了对Ara—C的耐受性:与对照组比较含耐药基因组动物经大剂量化疗后, 生存率明显提高(X2=7.42,P<0.01),血象、体质量下降幅度较小而恢复较快;转基因小鼠骨髓细胞经PCR检测,显示有CD基因条带. 结论:耐药基因可以进入小鼠骨髓细胞并且获得共表达,提高了造血细胞对Aar—C的耐受性.

Protection of a cytidine deaminase gene gainst toxicity of high dose chemotherapy in mice

Objective： To explore the feasibility of transfecting cytidine deaminase （CD） gene into mouse bone marrow cells in order to observe the drug resistance of high dose Ara-C and improve the tolerance of myelosuppression following combination chemotherapy. Methods： Human cytidine deaminase gene was transfected into mice bone marrow cells by retroviral vector. Resistant colony-forming unit granulocyte-macrophage （CFU-GM） assay was performed after the transfected mice bone marrow cells treated by the Ara-C. DNA was extracted from mice bone marrow cells. The drug resistant gene in mice bone marrow cells after transfection was detected by PCR. Results： Bone marrow cells of the donor mice cultured with the retroviral producer cells showed the drug resistant colonies and resistance to Ara-C, so did accept mice transplanted with the CD gene （CFU-GM of donor mice was 52%, χ^2 = 124.62, P 〈 0.01; accept mice was 54%, χ^2 = 126.26, P 〈 0.01, both compared with the contrast group）. The animal survival rate was significantly higher in gene transfected group than that of the control （χ^2= 7.42, P 〈 0.01）. CD gene of transfected bone marrow cells was confirmed by PCR. Conclusion： CD gene can be transfected into bone marrow cells of mice efficiently and increase the drug resistance to Ara-C.

中国急性白血病儿童与正常儿童CDA基因多态性研究

目的研究胞苷脱氨酶（cytidine deaminase,CDA）基因编码区单核苷酸多态性（coding single nucleotide polymorphisms,cSNPs）在急性白血病（acute leukemia,AL）患儿和正常中国儿童中的频率分布特征,为探讨CDA变异与AL患者阿糖胞苷化疗效应之间可能的相关性及肿瘤化疗个体化提供理论依据。方法采用变性梯度凝胶电泳、限制性片段长度多态性分析及DNA序列测定等方法对87例AL患儿和199名正常儿童的DNA进行了CDAcSNPs的筛查与鉴定,分析各基因型在两组之间的分布差异。结果在中国儿童CDA中鉴定了3种已知的cSNPs,即79A〉C（K27Q）、208G〉A（A70T）和435T〉C,其等位基因频率分别是12.1%、0.52%和76.2%。这些多态性与白血病的易感性无相关性。结论确定了中国儿童CDA中存在3种cSNPs以及各自的基因型分布和等位基因频率。提供了为预测不同个体间对脱氧胞苷同系物潜在敏感性差异的遗传学标志。