| 华凌,赖有方,孔祥慧,等.DNA模型的核苷酸对间转角参数对质子放射生物学效应影响的模拟研究[J].中华放射医学与防护杂志,2024,44(12):991-997.Hua Ling,Lai Youfang,Kong Xianghui,et al.A simulation study on the impact of nucleotide dihedral angles in DNA models on proton radiobiological effects[J].Chin J Radiol Med Prot,2024,44(12):991-997 |
| DNA模型的核苷酸对间转角参数对质子放射生物学效应影响的模拟研究 |
| A simulation study on the impact of nucleotide dihedral angles in DNA models on proton radiobiological effects |
| 投稿时间：2024-07-31 |
| DOI：10.3760/cma.j.cn112271-20240731-00294 |
| 中文关键词: 质子治疗 双链断裂产率 蒙特卡罗模拟 径迹结构 DNA模型 |
| 英文关键词:Proton therapy Double-strand break yields Monte Carlo simulation Track structure DNA model |
| 基金项目:国家自然科学基金(12275012、12475309、12411530076,82202941);北京市自然科学基金(Z210008);中央高校基本科研业务费/北京大学临床医学+X青年专项(PKU2024LCXQ033);教育部内地与港澳高等学校师生交流计划项目(万人计划7111400049);国家重点研发计划项目(2019YFF01014405);内蒙古自治区科技计划项目(2022YFSH0064) |
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| 中文摘要: |
| 目的 构建适用于蒙特卡罗径迹结构模拟的简化DNA模型,探究数个碱基对尺度上的微观结构参数对于质子生物学效应物理模拟的影响,为优化质子放疗物理模拟的建模及运算效率提供一种新思路。方法 参考pBR322质粒的结构,构建一个由4 362个碱基对构成的环状双螺旋链DNA分子,将其彼此不重叠地均匀分散在水箱模体中心的一个球体区域内作为细胞核。将该模型植入基于统一计算设备架构(CUDA)编程的gMicroMC代码框架,在相邻核苷酸对的扭转角分别为20°、36°与 72°的3个不同模型中模拟计算质子诱导双链断裂产率,针对不同模型间的差异进行对比研究。结果 在相同模型中,质子的双链断裂(DSB)产率随初动能变化均反映出了总体下降趋势;不同能量质子照射下3个模型的双链断裂产率均满足72°>36°>20°,且组间相对差异均在34.6%以上;通过相对生物效能(RBE)计算结果的对比验证,当转角取为 36°与 72°之间的某个值时,有望构建出更接近真实仓鼠肺细胞(V79)中质子诱导损伤的DNA结构模型。结论 通过分离DNA结构的宏观与微观层次进行合理简化,可使对微观结构参数的调节实现对模型的调整,提高建模及物理模拟的运算效率,有望在质子治疗计划设计中作为RBE模拟计算模型。 |
| 英文摘要: |
| Objective To develop a simplified DNA model tailored for Monte Carlo track structure simulations and investigate the influence of microstructural variations at the scale of several base pairs on the physical simulation of proton-induced biological effects, providing a novel approach to enhance the efficiency of modeling and computational processes in proton radiotherapy simulations. Methods A circular double-helix DNA molecule consisting of 4 362 base pairs was constructed based on the pBR322 plasmid structure. These molecules were evenly distributed without overlap within a spherical region at the center of a water phantom, representing the cellular nucleus. Integrated into the GPU-based gMicroMC code framework, the model facilitated simulations to calculate proton-induced double-strand break (DSB) yields across three distinct models with twist angles of 20°, 36°, and 72° between adjacent nucleotide pairs. Comparative analyses were conducted to assess differences among these models. Results Intra-model analyses revealed a consistent decrease in proton-induced DSB yields with increasing initial energy. Under proton irradiation at different energies, the DSB yields for the three models followed the order 72°>36°>20°, with intergroup relative differences exceeding 34.6%. Comparative RBE calculations suggested that models with twist angles between 36° and 72° may better replicate proton-induced damage observed in V79 cells. Conclusions By strategically simplifying the separation of macroscopic and microscopic levels of DNA structure, adjustments to microstructural parameters can be effectively implemented to refine the model, thereby enhancing the efficiency of modeling and physical simulations. This methodology shows potential as a model for simulating relative biological effectiveness (RBE) in proton therapy planning. |
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