Prostate Cancer–Associated Gene Expression Alterations Determined from Needle Biopsies

To accurately identify gene expression alterations that differentiate neoplastic from normal prostate epithelium using an approach that avoids contamination by unwanted cellular components and is not compromised by acute gene expression changes associated with tumor devascularization and resulting ischemia. Approximately 3,000 neoplastic and benign prostate epithelial cells were isolated using laser capture microdissection from snap-frozen prostate biopsy specimens provided by 31 patients who subsequently participated in a clinical trial of preoperative chemotherapy. To eliminate potential dye bias, we randomly alternated Cy3 and Cy5 labeling to neoplastic and benign epithelium across 31 samples. Labeled cDNA probes were hybridized in a head-to-head fashion, normal versus neoplastic from the same individual, to custom-made microarrays composed of 6,200 clones derived from the Prostate Expression Database.

本研究旨在精准识别可区分肿瘤性与正常前列腺上皮的基因表达改变，采用可规避无关细胞成分污染、且不受肿瘤血管断绝及继发缺血引发的急性基因表达变化影响的实验策略。研究人员从31名后续参与术前化疗临床试验的患者提供的快速冷冻前列腺活检标本中，通过激光捕获显微切割（Laser Capture Microdissection）分离出约3000个肿瘤性与良性前列腺上皮细胞。为消除潜在的染料偏倚，我们在31个样本中随机将Cy3、Cy5标记分别分配给肿瘤性与良性上皮组织。将标记后的cDNA探针以同个体正常上皮与肿瘤上皮两两配对的方式，与定制微阵列进行杂交；该微阵列包含源自前列腺表达数据库（Prostate Expression Database）的6200个克隆。