Dek overexpression under the environment exposed to carcinogen in oral squamous cell.. Mus musculus

Oral squamous cell carcinoma (OSCC) develop multi-step carcinogenesis, including the concept of the field cancerization. DEK gene is considered to be a proto-oncogene, has multifaceted functions, such as replication, transcription, and chromatin remodeling, and also affects oncogenic process, such as cellular proliferation, differentiation, senescence, and apoptosis. DEK overexpression has proposed to be closely associated with many malignancies, however, functional mechanisms and crucial roles are still unclear. DEK-expressing cells significantly increased in human oral squamous cell carcinogenesis. We generated ubiquitous and squamous cell-specific Doxycycline (DOX)- inducible Dek mice (iDek and iDek-e mice, respectively). DOX administrated (DOX+) iDek mice promoted field cancerization and the development of OSCC in the environment exposed to carcinogen. By the microarray expression profiling analysis, the promotion of the filed cancerization by Dek overexpression was mediated by the upregulation of DNA replication- and cell cycle (G1 to S phase transition)-related genes. Further, Dek-overexpressed tongue tumors were progressed by proliferating cell nuclear antigen (Pcna) and the elongator complex protein 3 (Elp3). Our data suggest that, by DEK overexpression enhances the carcinogenesis, including field cancerization, of OSCC stimulating the G1-to-S phase transition in the cell-cycle and DNA replication, even after carcinogen-exposed environment, and offers a fascinating target for treatment and prevention of OSCC. Overall design: For microarray analysis, total RNA (from mouse tongue tissue) was extracted with the Simply RNA tissue Kit (Promega, Fitchburg, Wisconsin (WI), USA) on a Maxwell RSC instrument. Gene expression analysis of the RNA samples was performed using by TAKARA Bio Inc. (Shiga, Japan) using Agilent Expression Array (SurePrint G3 Mouse GE 8 × 60 K Microarray). Two group2 (n=3 each) of Dek induced mice and Dek not induced mice

口腔鳞状细胞癌（Oral squamous cell carcinoma, OSCC）的发生遵循多步骤癌变进程，其中包含区域癌化（field cancerization）的概念。DEK基因被认定为原癌基因，具备多种核心功能，例如参与DNA复制、转录及染色质重塑，同时还可调控细胞增殖、分化、衰老与凋亡等致癌相关进程。现有研究提示DEK过表达与多种恶性肿瘤密切相关，但其具体功能机制与关键作用仍未阐明。在人类口腔鳞状细胞癌变过程中，DEK阳性细胞比例显著升高。本研究构建了泛组织及鳞状上皮细胞特异性的多西环素（Doxycycline, DOX）诱导型Dek小鼠模型（分别记为iDek小鼠与iDek-e小鼠）。在致癌物暴露环境下，经多西环素诱导（DOX+）的iDek小鼠可促进区域癌化形成与口腔鳞状细胞癌的发生。通过微阵列表达谱分析，我们发现DEK过表达对区域癌化的促进作用，是通过上调DNA复制及细胞周期（G1期向S期转换）相关基因实现的。进一步研究显示，DEK过表达的舌部肿瘤进展与增殖细胞核抗原（Proliferating Cell Nuclear Antigen, PCNA）及延伸复合物蛋白3（Elongator Complex Protein 3, ELP3）密切相关。本研究数据表明，DEK过表达可通过促进细胞周期G1/S期转换与DNA复制，增强口腔鳞状细胞癌的癌变进程（包括区域癌化形成），即便在致癌物暴露环境下亦如此，该发现为口腔鳞状细胞癌的治疗与预防提供了极具潜力的靶点。实验整体设计：用于微阵列分析的总RNA提取自小鼠舌组织，采用Simply RNA组织提取试剂盒（Promega公司，美国威斯康星州菲奇堡市）结合Maxwell RSC自动化核酸提取仪完成。RNA样本的基因表达分析由日本滋贺县TAKARA生物公司完成，实验采用安捷伦表达芯片（SurePrint G3 Mouse GE 8 × 60 K Microarray）。实验分为两组（每组n=3）：DEK诱导组与DEK非诱导组。