Gene expression and radiation response of two different types of neuroblastoma cell lines

Clonogenic assays were used to establish radiation responses for SK-N-AS, S-type and SK-N-DZ, N-type cell lines; cells were then irradiated at doses that cause 90% cell killing based on clonogenic assay and their RNA was isolated one hour post-irradiation. In addition, cells were transfected with pre-miRNA constructs that led to overexpression of micro-RNAs hsa-miR-34a and hsa-miR-1228. Statistically significant differences were detected for expression of several thousands of genes when the two cell lines were compared with each other. In comparison, radiation led only to minor, less than two-fold gene expression differences. Overexpression of micro-RNAs in either cell line did not change this outcome. Neuroblastoma cell line SK-N-AS was irradiated with 6Gy dose of X-rays 20-24h after transfection, cell line SK-N-DZ was processed the same way but the radiation dose was 4Gy. Gene expression at 1h after radiation was evaluated.

本研究采用克隆形成试验（Clonogenic Assay），明确SK-N-AS（S型）及SK-N-DZ（N型）细胞系的辐射应答特征；随后基于克隆形成试验结果，以可导致90%细胞杀伤的辐射剂量对细胞进行辐照，并于辐照后1小时提取细胞总RNA。此外，通过转染前体微RNA（pre-miRNA）构建体，分别实现微RNA（micro-RNA）hsa-miR-34a与hsa-miR-1228的过表达。对两种细胞系进行比较时，可检测到数千个基因的表达存在统计学显著性差异；相较之下，辐射仅引发了小于2倍的微弱基因表达变化，且两种细胞系中微RNA的过表达均未改变这一结果。神经母细胞瘤细胞系SK-N-AS于转染后20-24小时接受6Gy剂量的X射线辐照，细胞系SK-N-DZ采用相同实验流程处理，但辐照剂量调整为4Gy，并于辐照后1小时对其基因表达水平进行检测分析。