Jochumsen K M, Tan Q, Hølund B, Kruse T A, Mogensen O
Department of Obstetrics and Gynecology and Human MicroArray Centre, Odense University Hospital, Odense, Denmark.
Int J Gynecol Cancer. 2007 Sep-Oct;17(5):979-85. doi: 10.1111/j.1525-1438.2007.00908.x. Epub 2007 Mar 15.
The aim of this study was to investigate the intratumor heterogeneity of gene expression profiles in epithelial ovarian cancer (EOC). This was done to evaluate whether sampling of a single macrodissected tissue sample from each EOC case would bias the data and result in, eg, prognostic studies based on gene expression microarray experiments. From nine EOCs removed at Odense University Hospital, Denmark, three tumor samples of 200-300 mg each were taken with greatest possible mutual distance. The samples were immediately flash frozen. A parallel section was taken for histopathologic comparison. RNA was extracted from the tissue samples. Five micrograms of each RNA sample was used for labeling. The fragmented biotin-labeled complementary RNA was hybridized to Affymetrix GeneChip Human Genome U133 plus 2.0 arrays, and scanning was performed on the GeneArray scanner 3000 (Affymetrix, Santa Clara, CA). Data were evaluated using hierarchical clustering and intraclass correlation coefficient (ICC) from reliability analysis. All evaluation methods revealed low intratumor heterogeneity. Intratumor ICCs ranged from 0.888 to 0.978. In contrast, "between-tumor" ICC was 0.549 indicating much lower intra- than intertumor heterogeneity. Due to a low degree of intratumor variation, we conclude that it is sufficiently accurate in a clinical setup to use single, macrodissected tumor samples in the evaluation of gene expression in EOCs.
本研究的目的是调查上皮性卵巢癌（EOC）基因表达谱的肿瘤内异质性。这样做是为了评估从每个EOC病例中采集单个大体解剖组织样本是否会使数据产生偏差，并导致例如基于基因表达微阵列实验的预后研究出现偏差。从丹麦欧登塞大学医院切除的9例EOC中，尽可能相互距离最大地采集了3个每个200 - 300毫克的肿瘤样本。样本立即速冻。取平行切片进行组织病理学比较。从组织样本中提取RNA。每个RNA样本5微克用于标记。将片段化的生物素标记互补RNA与Affymetrix GeneChip Human Genome U133 plus 2.0阵列杂交，并在GeneArray扫描仪3000（Affymetrix，加利福尼亚州圣克拉拉）上进行扫描。使用层次聚类和可靠性分析中的组内相关系数（ICC）对数据进行评估。所有评估方法均显示肿瘤内异质性较低。肿瘤内ICC范围为0.888至0.978。相比之下，“肿瘤间”ICC为0.549，表明肿瘤内异质性远低于肿瘤间异质性。由于肿瘤内变异程度较低，我们得出结论，在临床环境中使用单个大体解剖肿瘤样本评估EOC中的基因表达足够准确。
