C57BL/6小鼠的血循环DNA的定量研究

Quantitative analysis of the circulating DNA in C57BL 6 mice

目的探讨循环DNA的定量检测在荷瘤C57BL/6小鼠中的应用价值。方法以异位接种法在C57BL/6小鼠中建立B16黑色素瘤肝转移模型,以”微量基因组抽提试剂盒”抽提血清DNA,用SYBR Green I斑点荧光染色法对DNA进行定量。结果在正常小鼠中,血循环DNA为(62.4±25.52)ng/mL、荷瘤伴有肝转移小鼠为(241±73.7)ng/mL(P<0.01);小鼠的血循环DNA水平与小鼠肝转移的分期相关,I期、Ⅱ期肝转移小鼠分别为(131.11±54.32)ng/mL和(170±10.96)ng/mL, Ⅲ期、Ⅳ期小鼠为(235±85.54)ng/mL和(271±65.76)ng/mL。用健脾理气中药抑制肿瘤生长和转移的同时,荷瘤小鼠血循环DNA也同步下降。结论循环DNA定量检测能客观反应小鼠荷瘤程度,并能动态反应药物的疗效,是一具有应用前景的肿瘤标志物。

Objective To determine the value of quantitative analysis of the circulating DNA in C57BL/6 mice. Methods Liver metastasis model was established in C57BL/6 mice. Serum DNA was extracted by commercial “genomic DNA extraction kit” and detected by fluorescent dye （SYBR green Ⅰ） staining. Results The mean value of circulating DNA in the healthy group was （62.4 ± 25.5） ng/mL, and that in the mice with liver metastasis group was （241±73.7） ng/mL, there was significant difference between the two groups（ P 〈0.01）. The circulating DNA of Ⅰ , Ⅱ ,Ⅲ and Ⅳ period in liver metastasis mice was （131.11± 54.32） ng/mL, （ 170±10.96） ng/mL, （235 ± 85.54） ng/mL and （271±65.76） ng/mL respectively, Jianpi-liqi Herbs could suppress the tumor growth and its liver metastasis, down regulate the mice with liver metastasis in the Jianpi-liqi Herbs plus Pixu group,depress the amount of circulating DNA. Conclusion Measuring circulating DNA could reflect the degree of mice with neoplasm and the effect of the drug, it also could complement with currently used tumor markers for the diagnosis of cancer,