Mertz Kirsten D, Setlur Sunita R, Dhanasekaran Saravana M, Demichelis Francesca, Perner Sven, Tomlins Scott, Tchinda Joëlle, Laxman Bharathi, Vessella Robert L, Beroukhim Rameen, Lee Charles, Chinnaiyan Arul M, Rubin Mark A
Department of Pathology, Brigham and Women's Hospital, Boston, MA 02115-6110, USA.
Neoplasia. 2007 Mar;9(3):200-6. doi: 10.1593/neo.07103.
Recent studies have established that a significant fraction of prostate cancers harbor a signature gene fusion between the 5' region of androgen-regulated TMPRSS2 and an ETS family transcription factor, most commonly ERG. Studies on the molecular mechanisms and functional consequences of this important chromosomal rearrangement are currently limited to the VCaP cell line derived from a vertebral bone metastasis of a hormone-refractory prostate tumor. Here we report on the NCI-H660 cell line, derived from a metastatic site of an extrapulmonary small cell carcinoma arising from the prostate. NCI-H660 harbors TMPRSS2-ERG fusion with a homozygous intronic deletion between TMPRSS2 and ERG. We demonstrate this by real-time quantitative polymerase chain reaction, a two-stage dual-color interphase fluorescence in situ hybridization (FISH) assay testing for TMPRSS2 and ERG break-aparts, and single-nucleotide polymorphism oligonucleotide arrays. The deletion is consistent with the common intronic deletion found on chromosome 21q22.2-3 in human prostate cancer samples. We demonstrate the physical juxtaposition of TMPRSS2 and ERG on the DNA level by fiber FISH. The androgen receptor-negative NCI-H660 cell line expresses ERG in an androgen-independent fashion. This in vitro model system has the potential to provide important pathobiologic insights into TMPRSS2-ERG fusion prostate cancer.
近期研究表明，相当一部分前列腺癌存在雄激素调节的跨膜丝氨酸蛋白酶2（TMPRSS2）5'区域与ETS家族转录因子（最常见的是ERG）之间的特征性基因融合。目前，关于这种重要染色体重排的分子机制和功能后果的研究仅限于源自激素难治性前列腺肿瘤椎体骨转移的VCaP细胞系。在此，我们报告了NCI-H660细胞系，它源自前列腺来源的肺外小细胞癌的转移部位。NCI-H660存在TMPRSS2-ERG融合，且TMPRSS2和ERG之间存在纯合内含子缺失。我们通过实时定量聚合酶链反应、检测TMPRSS2和ERG断裂分离的两阶段双色间期荧光原位杂交（FISH）分析以及单核苷酸多态性寡核苷酸阵列来证实这一点。该缺失与人类前列腺癌样本中21q22.2-3染色体上常见的内含子缺失一致。我们通过纤维FISH在DNA水平上证明了TMPRSS2和ERG的物理并列。雄激素受体阴性的NCI-H660细胞系以雄激素非依赖方式表达ERG。这个体外模型系统有可能为TMPRSS2-ERG融合前列腺癌提供重要的病理生物学见解。
