Modlich Olga, Prisack Hans-Bernd, Munnes Marc, Audretsch Werner, Bojar Hans
Institute of Chemical Oncology, University of Düsseldorf, Düsseldorf, Germany.
Clin Cancer Res. 2004 Oct 1;10(19):6418-31. doi: 10.1158/1078-0432.CCR-04-1031.
Our goal was to identify genes undergoing expressional changes shortly after the beginning of neoadjuvant chemotherapy for primary breast cancer.
The biopsies were taken from patients with primary breast cancer prior to any treatment and 24 hours after the beginning of the neoadjuvant chemotherapy. Expression analyses from matched pair samples representing 25 patients were carried out with Clontech filter arrays. A subcohort of those 25 paired samples were additionally analyzed with the Affymetrix GeneChip platform. All of the transcripts from both platforms were queried for expressional changes.
Performing hierarchical cluster analysis, we clustered pre- and posttreatment samples from individual patients more closely to each other than the samples taken from different patients. This reflects the rather low number of transcripts responding directly to the drugs used. Although transcriptional drug response occurring during therapy differed between individual patients, two genes (p21(WAF1/CIP1) and MIC-1) were up-regulated in posttreatment samples. This could be validated by semiquantitative and real-time reverse transcription-PCR. Partial least- discriminant analysis based on approximately 25 genes independently identified by either Clontech or Affymetrix platforms could clearly discriminate pre- and posttreatment samples. However, correlation of certain gene expression levels as well as of differential patterns and clusters as determined by a different platform was not always satisfying.
This study has demonstrated the potential of monitoring posttreatment changes in gene expression as a measure of the pharmacodynamics of drugs. As a clinical laboratory model, it can be useful to identify patients with sensitive and reactive tumors and to help for optimized choice for sequential therapy and obviously improve relapse- free and overall survival.
我们的目标是确定原发性乳腺癌新辅助化疗开始后不久发生表达变化的基因。
在任何治疗之前以及新辅助化疗开始24小时后，从原发性乳腺癌患者身上获取活检样本。使用Clontech滤膜阵列对代表25名患者的配对样本进行表达分析。对这25对配对样本中的一个亚组，另外使用Affymetrix基因芯片平台进行分析。查询两个平台的所有转录本的表达变化。
进行层次聚类分析时，我们发现单个患者治疗前和治疗后的样本彼此聚类得比来自不同患者的样本更紧密。这反映了直接对所用药物产生反应的转录本数量相当少。尽管治疗期间个体患者发生的转录药物反应有所不同，但两个基因（p21（WAF1/CIP1）和MIC-1）在治疗后的样本中上调。这可以通过半定量和实时逆转录PCR进行验证。基于由Clontech或Affymetrix平台独立鉴定的约25个基因的偏最小判别分析可以清楚地区分治疗前和治疗后的样本。然而，不同平台确定的某些基因表达水平以及差异模式和聚类的相关性并不总是令人满意。
本研究证明了监测基因表达的治疗后变化作为药物药效学指标的潜力。作为一种临床实验室模型，它有助于识别具有敏感和反应性肿瘤的患者，并有助于优化序贯治疗的选择，显然可以提高无复发生存率和总生存率。
