National Heart and Lung Institute, Imperial College London, London, United Kingdom.
J Mol Diagn. 2012 Mar-Apr;14(2):140-8. doi: 10.1016/j.jmoldx.2011.11.002. Epub 2012 Jan 10.
Gene expression profiling could assist in revealing biomarkers of lung cancer prognosis and progression. The handling of biological samples may strongly influence global gene expression, a fact that has not been addressed in many studies. We sought to investigate the changes in gene expression that may occur as a result of sample processing time and conditions. Using Illumina Human WG-6 arrays, we quantified gene expression in lung carcinoma samples from six patients obtained at chest opening before and immediately after lung resection with storage in RNAlater [T1a((CO)) and T1b((LR))], after receipt of the sample for histopathology, placed in RNAlater [T2a((HP))]; snap frozen [T2b((HP.SF))]; or snap frozen and stored for 1 week [T2c((HP.SFA))], as well as formalin-fixed, paraffin-embedded (FFPE) block samples. Sampling immediately after resection closely represented the tissue obtained in situ, with only 1% of genes differing more than twofold [T1a((CO)) versus T1b((LR))]. Delaying tissue harvest for an average of 30 minutes from the operating theater had a significant impact on gene expression, with approximately 25% of genes differing between T1a((CO)) and T2a((HP)). Many genes previously identified as lung cancer biomarkers were altered during this period. Examination of FFPE specimens showed minimal correlation with fresh samples. This study shows that tissue collection immediately after lung resection with conservation in RNAlater is an optimal strategy for gene expression profiling.
基因表达谱分析有助于揭示肺癌预后和进展的生物标志物。生物样本的处理可能会强烈影响全局基因表达，这一事实在许多研究中都没有得到解决。我们试图研究由于样本处理时间和条件的变化可能导致的基因表达变化。使用 Illumina Human WG-6 阵列，我们定量分析了来自 6 名患者的肺癌样本的基因表达，这些样本在开胸后立即在肺切除前获得，然后立即储存在 RNAlater 中 [T1a((CO)) 和 T1b((LR))]，在收到用于组织病理学的样本后，储存在 RNAlater 中 [T2a((HP))]；立即冷冻 [T2b((HP.SF))]；或立即冷冻并储存 1 周 [T2c((HP.SFA))]，以及福尔马林固定、石蜡包埋 (FFPE) 块样本。切除后立即采样与原位获得的组织非常相似，只有 1%的基因差异超过两倍 [T1a((CO)) 与 T1b((LR))]。从手术室延迟采集组织平均 30 分钟，对基因表达有显著影响，T1a((CO)) 和 T2a((HP)) 之间大约有 25%的基因不同。在此期间，许多先前被鉴定为肺癌生物标志物的基因发生了改变。对 FFPE 标本的检查显示与新鲜样本相关性最小。本研究表明，在肺切除后立即用 RNAlater 保存采集组织是基因表达谱分析的最佳策略。
