Burger A, Li H, Zhang X K, Pienkowska M, Venanzoni M, Vournakis J, Papas T, Seth A
Clinical Oncology Unit, University of Bradford, UK.
Oncogene. 1998 Jan 22;16(3):327-33. doi: 10.1038/sj.onc.1201517.
To determine which genes may be activated or inactivated during breast cancer development, we employed two cloning strategies (subtractive hybridization and differential display) using RNA samples from a human breast tumor and its matching normal breast cell line. Of 950 clones isolated, 102 cDNA inserts were analysed by DNA sequencing and database searching. We found 30 clones that were obviously unidentified, with no significant homology to any listed human gene. We focused upon one of the novel genes, Di12, that is differentially expressed as a 1.35 kb RNA in breast cancer tissues and cell-lines, and in several normal tissues. A full length cDNA of this gene was cloned, and its DNA sequence revealed an open reading frame of 339 amino acids. Antibodies to the ten N-terminal amino acids were developed to investigate the expression of Di12 in breast cancer cell-lines and tumors. The Di12 protein was found in tissue sections of infiltrating ductal carcinomas (IDCs), but not in benign or normal breast specimens. RT-PCR analysis confirmed expression of Di12 in 80% of infiltrating ductal carcinomas (IDCs). As IDC constitutes approximately 70% of breast cancers seen clinically, the level of Di12 expression may be predictive of disease progression.
为了确定在乳腺癌发展过程中哪些基因可能被激活或失活，我们采用了两种克隆策略（消减杂交和差异显示），使用来自人类乳腺肿瘤及其匹配的正常乳腺细胞系的RNA样本。在分离出的950个克隆中，通过DNA测序和数据库搜索对102个cDNA插入片段进行了分析。我们发现30个克隆明显未被鉴定，与任何已列出的人类基因均无显著同源性。我们重点研究了其中一个新基因Di12，它在乳腺癌组织和细胞系以及几种正常组织中作为一种1.35 kb的RNA差异表达。克隆了该基因的全长cDNA，其DNA序列显示有一个339个氨基酸的开放阅读框。制备了针对前十个N端氨基酸的抗体，以研究Di12在乳腺癌细胞系和肿瘤中的表达。在浸润性导管癌（IDC）的组织切片中发现了Di12蛋白，但在良性或正常乳腺标本中未发现。逆转录聚合酶链反应（RT-PCR）分析证实，80%的浸润性导管癌（IDC）中有Di12表达。由于IDC约占临床所见乳腺癌的70%，Di12的表达水平可能预示疾病进展。
