权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Analysis of IGF-I receptor transcriptional regulation by mutant p53 and its clinical implication

突变型p53对IGF-I受体转录调控的分析及其临床意义

基本信息

批准号：
16591661
负责人：
HONGO Atsushi
金额：
$ 2.3万
依托单位：
Okayama University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2005
项目状态：
已结题

项目摘要

The role of wild type p53 on IGF-I receptor expression was studied in cervical cancer derived cell lines SiHa and HeLa S3 harboring HPV. Transient transfection of E6 into SiHa cells downregulated p53, and upregulated IGF-I receptor. In contrast, transient transfection of E2 into HeLa S3 cells upregulated p53, and downregulated IGF-I receptor. We could reconfirm these phenomena by establishing stable transformants of these genes. Luciferase assay driven by IGF-I receptor promoter revealed that these alternation of IGF-I receptor expression was based on transcriptional regulation. Alternation of IGF-I receptor expression within these stable transformants did effect on their anchorage-independent growth in soft agar, and tumorigenesity in nude mice.Then, expression levels and their tyrosil phosphorylated status in human cervical specimens were evaluated by immunohistochemistry. IGF-I receptor expression levels were significantly promoted in CIN III lesions and more. Phosphorylated IGF-I receptor was observed in all CIN and invasive cancer specimens, and its promotion was related to the progression of the disease.Then, transcriptional regulation on IGF-I receptor by mutant p53 was evaluated. We constructed expression vectors encoding wild type and various p53 mutants especially within hot spot mutation areas. Luciferase assay after transient transfection of these wild type and mutant p53 genes showed different transcriptional regulations of IGF-I receptor. Wild type as well as P72R and V143A mutants downregulated IGF-I receptor transcription, whereas other mutants T123A, R175H, R248Q, R273H had no effect.

在携带HPV的宫颈癌衍生细胞系SiHa和HeLa S3中研究了野生型p53对IGF-I受体表达的作用。E6瞬时转染SiHa细胞下调p53，上调IGF-I受体。相反，E2瞬时转染HeLa S3细胞上调p53，下调IGF-I受体。我们可以通过建立这些基因的稳定转化体来再次证实这些现象。由IGF-I受体启动子驱动的荧光素酶分析表明，IGF-I受体表达的这些变化是基于转录调控。这些稳定的转化子中IGF-I受体表达的改变影响其在软琼脂中的非贴壁生长和裸鼠的致瘤性。IGF-I受体表达水平在CIN III病变中显著升高。在所有CIN和浸润性癌标本中均观察到IGF-I受体的磷酸化，且其表达水平的升高与疾病的进展有关。我们构建了编码野生型和各种p53突变体的表达载体，特别是在热点突变区。瞬时转染野生型和突变型p53基因后的荧光素酶测定显示IGF-I受体的不同转录调控。野生型以及P72 R和V143 A突变体下调IGF-I受体转录，而其他突变体T123 A，R175 H，R248 Q，R273 H没有影响。