Function allotment analysis of the cold shock protein in a somatic cell and the generative cell

本研究的结果如下(1)~(7)。(1)对乳腺癌紫杉醇耐药的分子机制进行了分析，认为dbpB/YB-1是参与乳腺癌紫杉醇耐药的重要分子。(2)制备了抗dbpC/Contrin的抗体，检测了正常组织和癌组织的表达。结果表明，dbpC/Contrin是一种肿瘤/睾丸抗原。(3)检测了在生殖细胞肿瘤中的基因表达及其在细胞内的定位。结果，我们在启动子中发现了一个重要的损伤，并在DBpC/Contrin的C末端发现了一个控制细胞定位的重要结构域。(4)YB-1基因敲除小鼠为胚胎致死型，表现为脑外畸形，β-肌动蛋白表达减少，F-肌动蛋白形成减少。此外，来自YB-1(-/-)胚胎的成纤维细胞生长和细胞密度降低。这些结果表明YB-1参与了小鼠的早期发育。(5)用高密度寡核苷酸芯片研究了YB-1小干扰RNA(SiRNA)转基因卵巢癌细胞的表达谱。提示Akt激活调控了YB-1的核转位，影响了卵巢癌细胞耐药基因和其他恶性相关基因的表达。(6)我们发现Twist在顺铂耐药细胞中高表达，提示YB-1是Twist的靶基因，YB-1和Twist的表达可以诱导肿瘤细胞生长。(7)我们发现Twist与抑癌基因产物P53相关，并且这种相互作用降低了P53激活的p21基因的表达和Twist激活的YB-1基因的表达。此外，我们还阐明了这些转录表达的分子机制。

The result of this study is next (1)〜(7). (1)We analyzed molecular mechanism of the paclitaxel resistance in the breast cancer., As a result, it was thought that dbpB/YB-1 was the important molecule which participated in paclitaxel resistance in the breast cancer. (2) We made an antibody against dbpC/Contrin and examined the expression of normal and cancer tissue. As a result, it was suggested that dbpC/Contrin became a Cancer/Testis Antigen. (3) We examined the gene expression of dbpC/Contrin in the germ cell tumor and the localization in the cell. As a result, we identified an important lesion in the promoter and an important domain that controlled cellular localization in a C terminus of dbpC/Contrin. (4) YB-1 knock-out mice was embryonic lethal and exhibited exencephaly associated with reduction of β-Actin expression and F-actin formation. In addition, fibroblasts derived from YB-1 (-/-) embryos demonstrated reduced growth and cell density. These results demonstrated that YB-1 was involved in early mouse development. (5) We investigated the expression profile of YB-1 small-interfering RNA (siRNA)-transfected ovarian cancer cells using a high-density oligonucleotide array. It was suggested that Akt activation regulated the nuclear translocation of YB-1, affecting the expression of drug-resistance genes and other genes associated with the malignant characteristics in ovarian cancer cells. (6) We found that Twist was overexpressed in cisplatin-resistant cells, and it was suggested that YB-1 was a target gene of Twist and that YB-1 and Twist expression could induce tumor cell growth. (7) We found that Twist was associated with tumor suppressor gene product p53, and these interaction reduced p21 gene expression activated by p53 and YB-1 gene expression activated by Twist. Furthermore we clarified molecular mechanism of these transcriptional repressions.