广东阳江高本底辐射地区居民适应性反应机制研究

Mechanism study of adaptive response in high background radiation area of Yangjiang in China

目的 通过检测广东阳江天然高本底辐射地区（high background radiation area,HBRA）和对照低辐射地区（control area,CA）居民晚期糖基化终产物受体（receptor for advanced glycation endproducts,RAGE）和钙结合蛋白S100A6 mRNA及蛋白的表达,研究HBRA居民适应性反应机制.方法 以HBRA及CA居民为研究对象,分别选取50～60岁健康无遗传疾病家族史的男性长住居民各53名,收集血液及痰液样品,逆转录PCR（RT-PCR）检测血细胞中RAGE和S100A6 mRNA的表达,Western Blotting方法 分析痰细胞中RAGE和S100A6蛋白的表达.热释光剂量计（thermo luminescent dosemeter,TLD）检测居民暴露水平的外照射剂量及评估年有效剂量.结果 CA和HBRA组的平均年有效剂量分别为1.95 mSv和6.24 mSv,HBRA组的剂量约为CA组的3倍.与CA组相比,HBRA组居民RAGE与S100A6 mRNA与蛋白的表达量均有明显下降：以β-肌动蛋白（β-actin）为内参,血细胞mRNA中,RAGE和S100A6在CA组的相对中位表达量分别为0.28和1.06;而在HBRA组中分别为0.16和0.79,以Wilcoxon秩和检验分析,两者差异有统计学意义（Z值分别为-2.587和-2.328,P〈0.05）.痰细胞总蛋白中,以β-actin为内参,RAGE和S100A6在CA组的相对中位表达量分别为2.98和2.25;而在HBRA组中分别为0.53和0.47,以Wilcoxon秩和检验分析,两者差异有统计学意义（Z值分别为-2.201和-2.366,P〈0.05）.结论 长期接受天然高本底辐射的人群中RAGE及S100A6的表达量降低,可能与HBRA居民的适应性反应及低癌症死亡率有关.

Objective To study the adaptive response mechanisms in high background radiation area（HBRA） among Yangjiang local people through gene and protein expression of receptor for advanced glycation endproducts （RAGE） and S100A6 in peripheral blood and sputum in inhabitants of HBRA. Methods A total of 53 male inhabitants were selected from HBRA in Yangjiang as the exposure group, while 53 male inhabitants were selected from Enping （control area, CA）as the control group. The content of RAGE and S100A6 gene and protein were detected by RT-PCR and Western blotting assay. Thermo luminescent dosemeter（TLD） assay was used to measure the outside dose and estimate the effective dose. Results The effective dose in CA and HBRA was respectively 1.95 mSv and 6. 24 mSv,which was 3 fold difference. Compared with CA, RAGE and S100A6 expression were significantly reduced in both gene and protein level in HBRA. The relative median mRNA expression of RAGE and S100A6 in peripheral blood were respectively 0. 28,1.06 and 0. 16,0. 79 in CA and HBRA group,there was significance （with analysis Z values of - 2. 587 and - 2. 328 respectively,P 〈 0. 05） with Wilcoxon rank test. For the protein of sputum, the relative median expression were respectively 2. 98, 2. 25 and 0. 53,0. 47 with significant difference （with analysis Z values of - 2. 201 and - 2. 366 respectively, P 〈 0. 05） by Wilcoxon rank test. Conclusion The low expression of RAGE and S100A6 in HBRA group might be correlated with the adaptive response and the low mortality of cancer in HBRA.