Glaesener Stephanie, Honecker Friedemann, Veltman Imke M, Gillis Ad J M, Rohlfing Tina, Streichert Thomas, Otto Benjamin, Brummendorf Tim H, Looijenga Leendert H J, Bokemeyer Carsten, Balabanov Stefan
Department of Oncology/Hematology/Bone Marrow Transplantation with the section of Pneumology, University Hospital Hamburg Eppendorf, Germany.
J Proteome Res. 2008 Sep;7(9):3890-9. doi: 10.1021/pr800173g. Epub 2008 Jul 22.
Whereas clinical differences between testicular and extragonadal germ cell tumors (GCT), like reduced cisplatin sensitivity of extragonadal tumors, are well-established, little is known about underlying tumor biology. A combined approach using global proteome analysis and RT-PCR to assess mRNA levels of selected proteins on the one hand, and array comparative genomic hybridization (array-CGH), on the other hand, was used to compare two germ cell tumor (GCT) cell lines showing embryonal carcinoma histology, one of testicular, and one of extragonadal origin. Overall, the two cell lines show remarkably similar protein profiles. In total, 66 proteins were found to be differentially expressed in an at least 2-fold manner. Of these, 35 proteins (53%) could be positively identified by peptide mass fingerprinting and database search. mRNA levels of 27 differentially expressed proteins were analyzed by RT-PCR. In 17/27 genes (63%), differences in mRNA expression corresponded with differences detected on protein level, suggesting that these proteins are mainly regulated through transcription. Interestingly, no close correlation was found between proteomic and genomic analysis: 13/30 genes (43%) with higher protein levels in one cell line showed higher copy numbers of the respective gene loci in array-CGH analysis. Corresponding differences from proteome, transcriptome, and mRNA analyses were found in 9 of 27 proteins (33%). Several proteins potentially involved in cisplatin resistance were identified in the extragonadal cell line, suggesting that the cisplatin-resistant phenotype of this cell line is multifactorial. Furthermore, our data demonstrate that a combined approach of proteome, transcriptome, and genome analysis is a promising tool to gain information on gene regulation in human tumors.
虽然睾丸生殖细胞肿瘤（GCT）和性腺外生殖细胞肿瘤之间的临床差异已得到充分证实，如性腺外肿瘤对顺铂的敏感性降低，但对其潜在的肿瘤生物学知之甚少。一方面，采用全球蛋白质组分析和RT-PCR相结合的方法来评估所选蛋白质的mRNA水平，另一方面，采用阵列比较基因组杂交（array-CGH）来比较两种显示胚胎癌组织学的生殖细胞肿瘤（GCT）细胞系，一种起源于睾丸，另一种起源于性腺外。总体而言，这两种细胞系显示出非常相似的蛋白质谱。总共发现66种蛋白质以至少2倍的方式差异表达。其中，35种蛋白质（53%）可通过肽质量指纹图谱和数据库搜索得到明确鉴定。通过RT-PCR分析了27种差异表达蛋白质的mRNA水平。在17/27个基因（63%）中，mRNA表达的差异与蛋白质水平检测到的差异相对应，表明这些蛋白质主要通过转录进行调控。有趣的是，蛋白质组学和基因组分析之间未发现密切相关性：在一个细胞系中蛋白质水平较高的13/30个基因（43%）在阵列CGH分析中显示相应基因位点的拷贝数较高。在27种蛋白质中的9种（33%）中发现了与蛋白质组、转录组和mRNA分析相对应的差异。在性腺外细胞系中鉴定出了几种可能与顺铂耐药有关的蛋白质，这表明该细胞系的顺铂耐药表型是多因素的。此外，我们的数据表明，蛋白质组、转录组和基因组分析相结合的方法是获取人类肿瘤基因调控信息的一种有前途的工具。
