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Elucidation of mechanisms of tumorigenesis and invasiveness of pancreatic cancer by gene rearrangement using immortalized pancreatic epithelial cells.

使用永生化胰腺上皮细胞进行基因重排，阐明胰腺癌的肿瘤发生和侵袭机制。

基本信息

批准号：
14370386
负责人：
FUJIMOTO Koji
金额：
$ 6.14万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2003
项目状态：
已结题

项目摘要

Pancreatic ductal adenocarcinomas arise through the accumulation of certain genetic alterations including ras, p16, p53, and DPC4. We found that activation of ras and inactivation of p53 could cooperatively induce in vitro tumorigenicity in conditionally immortalized pancreatic epithelial (IMPE) cells. IMPS cells were established from transgenic mice bearing a, temperature-sensitive mutant SV40 Large T (LT) antigen. IMPS cells-grew continuously under permissive conditions (33℃ with interferon-γ), but rapidly suffered growth arrest under non-permissive conditions (39℃ without interferon-γ). The cells showed strong expression of E-cadherin and β-catenin as epithelial markers, and cytokeratin 19, a specific ductal cell marker. Cell proliferation under permissive conditions was associated with down-regulation of p21 expression through inactivation of p53 after over-expression of LT antigen. Intriguingly, the shift from the permissive to non-permissive culture conditions caused G2/M arrest of IMPE cells. Although the cells did not form colonies when cultured in soft agar without activation of ras, cells with ras activation via, an adenovirus vector formed colonies under permissive conditions. These findings suggest that activation of ras and inactivation of p53 can cooperatively induce anchorage-independent growth of IMPE cells.Recent studies have demonstrated that TGF-β1 expression is markedly enhanced in invasive ductal pancreatic adenocarcinomas (DPA), although the precise role of TGF-β1 in pancreatic carcinogenesis remains unclear. We analyzed TGF-β1 expression in pancreatic intraepithelial neoplasias (PanINs) and the effects of chronic TGF-β1 exposure on conditionally immortalized pancreatic epithelial (IMPS) cells. We have clarified that TGF-β1 expression in PanINs and neoplastic transformation of IMPE cells by long-term exposure to TGF-β1 suggest that TGF-β1 may act as a tumor promoter in the early stage of pancreatic carcinogenesis.

胰腺导管腺癌是通过某些基因改变的积累而发生的，包括ras、p16、p53和DPC 4。我们发现ras的激活和p53的失活可以协同诱导条件永生化胰腺上皮细胞（IMPE）的体外致瘤性。IMPS细胞由携带温度敏感性突变体SV 40大T（LT）抗原的转基因小鼠建立。IMPS细胞在允许的条件下（33℃，有干扰素-γ）持续生长，但在非允许的条件下（39℃，无干扰素-γ）迅速生长停滞。细胞显示作为上皮标志物的E-钙粘蛋白和β-连环蛋白以及特异性导管细胞标志物细胞角蛋白19的强表达。许可条件下的细胞增殖与通过LT抗原过表达后p53失活而下调p21表达相关。有趣的是，从允许到非允许的培养条件的转变导致IMPE细胞的G2/M停滞。尽管当在没有ras活化的软琼脂中培养时细胞不形成集落，但是经由腺病毒载体具有ras活化的细胞在允许条件下形成集落。这些结果表明ras的激活和p53的失活可以协同诱导IMPE细胞的非贴壁依赖性生长。最近的研究表明，TGF-β1在侵袭性胰腺导管腺癌（DPA）中的表达显著增强，但TGF-β1在胰腺癌发生中的确切作用尚不清楚。我们分析了TGF-β1在胰腺上皮内瘤变（PanIN）中的表达以及长期TGF-β1暴露对条件永生化胰腺上皮（IMPS）细胞的影响。我们已经阐明了TGF-β1在PanINs中的表达和长期暴露于TGF-β1的IMPE细胞的肿瘤转化，表明TGF-β1可能在胰腺癌发生的早期阶段作为肿瘤促进剂。