阳江高本底地区居民外周血血浆miRNAs的表达

目的探讨天然高本底辐射对居民外周血血浆miR-16、miR-106b、miR-449a、miR-34a和let-7g表达的影响。方法采用单纯随机抽样法，分别从高本底地区和对照地区各选取55例50岁以上长期居住在当地的健康女性居民作为调查对象，调查年龄、体质量指数（BMI）等指标，并计算个人累积剂量。采用实时荧光定量PCR（RT-PCR）方法，检测研究对象外周血血浆中miRNAs的相对表达水平。采用t检验分析高本底组和对照组的个人累积剂量、年龄和BMI等基本情况，用Mann-Whitney U检验比较两组miRNAs表达水平的差异，选择剂量、年龄和BMI等变量，进行多因素回归分析。结果高本底组居民个人累积剂量约为对照组的4倍（t=42.803，P<0.05）。与对照组相比，高本底组居民外周血血浆中miR-16和miR-106b的表达水平均下调，miR-449a的表达水平上调，差异均有统计学意义（Z=4.180、2.422、2.794，P<0.05）。多因素回归分析表明，在控制年龄和BMI影响因素后，miR-16和miR-106b的相对表达水平和个人累积剂量呈负相关（P<0.05），而miR-449a、miR-34a和let-7g的相对表达水平与个人累积剂量未发现相关（P>0.05）。结论miR-16和miR-106b可作为长期低剂量辐射健康影响的早期标志物。

MicroRNA expressions in peripheral blood plasma of the residents from high background radiation area of Yangjiang, China

Objective To explore the effects of high background radiation on the expressions of miR-16, miR-106b, miR-449a, miR-34a and let-7g in peripheral blood plasma of the residents.Methods Totally 110 healthy female long-term local residents aged over 50 years were randomly selected from the high background radiation area and the control area, while their age, body mass index(BMI) and other indicators were surveyed. The relative expression levels of miRNAs in peripheral blood plasma of these women were quantitatively detected by real-time fluorescence quantitative PCR (RT-PCR). Then t-test was used to analyze the cumulative dose, age and BMI between the high background and control group. Mann-Whitney U-test was used for statistical analysis of miRNA expression levels between two groups, and the multiple regression analysis was used finally. Results Compared with the control group, the cumulative dose of individuals in the high background group was about four times higher (t=42.803, P<0.05), and the levels of miR-16 and miR-106b in plasma of high background group were down-regulated, while the level of miR-449a was up-regulated (Z=4.180, 2.422, 2.794, P<0.05). After controlling of confounding factors such as age and BMI, the expression levels of miR-16 and miR-106b were negatively correlated with the cumulative dose of individuals (P<0.05). On the contrary, no significant correlation was observed between the levels of miR-449a, miR-34a, let-7g and the individual cumulative dose (P>0.05). Conclusions miR-16 and miR-106b may serve as biomarkers for the early stage of low dose radiation health effects.