Ruf Christian G, Port Matthias, Schmelz Hans-Ulrich, Wagner Walter, Müller Felix, Senf Sven, Matthies Cord, Müller-Myhsok Bertram, Meineke Viktor, Abend Michael
Department of Urology, Federal Armed Forces Hospital, Hamburg, Germany; Bundeswehr Institute of Radiobiology, Munich, Germany.
Bundeswehr Institute of Radiobiology, Munich, Germany; Department of Hematology, Hemostasis, Oncology and Stem Cell Transplantation, University Hospital Hannover, Hannover, Germany.
PLoS One. 2014 May 1;9(5):e95009. doi: 10.1371/journal.pone.0095009. eCollection 2014.
The aim of the present study was to examine the biological differences between seminomas with occult and clinically apparent metastases at the time of diagnosis of the primary tumor to gain insight into the biology of these tumors and facilitate the identification of novel predictors of seminoma metastasis.
Total RNA including small RNAs was isolated from testicular tumors of patients with pure seminoma presenting with lymphogenic metastasis (n = 5, clinical stage IIb/c) and occult metastasis (n = 5, clinical stage I). The regulation of biological processes was examined (1) throughout the mRNA transcriptome (whole genome microarrays, 8×60 K Array, Agilent with 4 samples/group) and (2) the miRNA transcriptome employing small RNA next generation sequencing (SOLID, Life Technologies with 5 samples/group). Protein coding genes (mRNAs) and small RNAs showing a significant (≥2-fold) difference between the groups were identified. Finally (3), we examined 95 candidate miRNAs in 36 apparent metastasized and another 5 occult metastasized seminoma using logistic regression analysis.
Among 19,596 genes, on average 12,894 mRNAs appeared expressed (65.8%, SD+/-2.4; range, 62.0-69.3%) and 16.99×106/13.94×106 small RNA reads were identified for apparent/occult metastasized seminoma. These reads on average convert into 9,901/9,675 small RNAs including 422/404 mature microRNAs. None of these mRNAs/small RNAs met our selection criteria for candidate genes. From 95 candidate miRNAs 44 appeared expressed, with 3 of them showing weak but significant (p = 0.05) differences among both groups.
Occult and apparent metastasized seminomas are biologically almost indistinguishable and probably represent no separate tumor entities. These findings may simplify future research on seminoma metastasis.
本研究旨在探讨原发性肿瘤诊断时伴有隐匿性转移和临床明显转移的精原细胞瘤之间的生物学差异，以深入了解这些肿瘤的生物学特性，并有助于识别精原细胞瘤转移的新预测指标。
从伴有淋巴转移（n = 5，临床分期IIb/c）和隐匿性转移（n = 5，临床分期I）的纯精原细胞瘤患者的睾丸肿瘤中分离包括小RNA在内的总RNA。检测生物学过程的调控情况：（1）通过mRNA转录组（全基因组微阵列，8×60 K芯片，安捷伦，每组4个样本）；（2）采用小RNA下一代测序技术（SOLiD，生命技术公司，每组5个样本）检测miRNA转录组。鉴定出两组之间存在显著差异（≥2倍）的蛋白质编码基因（mRNA）和小RNA。最后（3），我们采用逻辑回归分析在36例临床明显转移和另外5例隐匿性转移的精原细胞瘤中检测了95个候选miRNA。
在19,596个基因中，平均有12,894个mRNA表达（65.8%，标准差±2.4；范围，62.0 - 69.3%），在临床明显转移/隐匿性转移的精原细胞瘤中分别鉴定出16.99×10⁶/13.94×10⁶个小RNA读数。这些读数平均转化为9,901/9,675个小RNA，包括422/404个成熟微小RNA。这些mRNA/小RNA均未达到我们的候选基因选择标准。95个候选miRNA中有44个表达，其中3个在两组之间显示出微弱但显著（p = 0.05）的差异。
隐匿性转移和临床明显转移精原细胞瘤在生物学上几乎无法区分，可能并不代表独立的肿瘤实体。这些发现可能会简化未来精原细胞瘤转移的研究。
