CONTROL MECHANISM OF RADIORESISTANT HYPOXIC CELLS IN MUTICELLULAR TUMOR SPHEROIDS

多细胞肿瘤球体中抗辐射缺氧细胞的控制机制

• 批准号: 10470399
• 负责人: SASAKI Takehito
• 金额: $ 7.17万
• 依托单位: TOKYO MEDICAL AND DENTAL UNIVERSITY(TMDU)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B).
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-10470399/
• 关键词: radioresistance; spheroid; apoptosis; IGF-IR; hypoxic cells; knockout mouse; glioblastoma cells; 神経膠芽腫細胞

Human glioblastoma cells(A-7)transfected with plasmid containing human IGF-IR cDNA(A7(R)), or co-transfected with that containing only puromycin-resistant gene(A7(puro))were established in this study. Overexpression of IGF-IR resulted in the loss of necrotic zone in A7(R)spheroids, whereas spheroids of A7(puro)cells showed a central necrosis. Together with faster growth rate in the spheroids of A7(R)cells, it was suggested that tumors consisting cells with overexpression of IGF-IR grow faster with reduced formation of necrosis. A7(R)cells in spheroids, however, showed a higher radiosensitivity than A7(puro)cells and the radiosensitivity was dependent on a size of dose fraction.Role of IGF-IR in severely hypoxic cells was studied using fibroblasts derived from knockout mouse of IGF-IR(R-), or cells transfected with human IGF-IR cDNA(R+). (R+)cells survived longer than(R-)cells in a hypoxic condition of less than 3 mm Hg of partial oxygen pressure, and were more radioresistant than(R-)cells in the hypoxic condition. (R+)cells grown in confluent state exfoliated in a short time from the surface of petri dish, indicating that these cells tend to die rapidly depending on the cell density in a severely hypoxic condition.

本研究建立了含人IGF-IR cDNA的质粒（A7（R））转染的人胶质母细胞瘤细胞（A-7），以及与仅含嘌呤霉素抗性基因的质粒（A7（puro））共转染的人胶质母细胞瘤细胞（A-7）。IGF-IR的过表达导致A7（R）球状体中坏死区的丧失，而A7（puro）细胞的球状体显示中心坏死。连同A7（R）细胞的球状体中更快的生长速率，表明由IGF-IR过表达的细胞组成的肿瘤生长更快，坏死形成减少。用IGF-IR基因敲除小鼠成纤维细胞（R-）和转染人IGF-IR cDNA的细胞（R+）研究了IGF-IR在严重缺氧细胞中的作用。（R+）细胞在氧分压小于3 mmHg的缺氧条件下比（R-）细胞存活更长时间，并且在缺氧条件下比（R-）细胞更具放射抗性。在汇合状态下生长的（R+）细胞在短时间内从培养皿表面脱落，表明这些细胞在严重缺氧条件下根据细胞密度倾向于迅速死亡。

项目成果

佐々木武仁: "Chemoradiotherapyの生物学的基礎"肺癌の臨床. 2. 5-14 (1999)

Takehito Sasaki：“放化疗的生物学基础”临床肺癌2. 5-14 (1999)。

佐々木武仁: "Chemoradiotherapy の生理学的基礎"肺癌の臨床. 2. 5-14 (1999)

Takehito Sasaki：“放化疗的生理学基础”肺癌的临床实践2. 5-14 (1999)。

Miura Masahiko: "Method in Molecular Biology, Vol.113: DNA Repair Protocols; Eukaryotic Systems, D.S. Henderson ed"Human Press Inc., Totowa, NJ, U.S.A. 6 (1999)

Miura Masahiko：“分子生物学方法，第 113 卷：DNA 修复方案；真核系统，D.S. Henderson 编辑”Human Press Inc.，Totowa，NJ，U.S.A. 6 (1999)

Sasaki T: "Recent reappraisal on the effect of radiation in the low dose domain. In "Oral and Maxillofacial Radiology Today""H.Fuchihata ed., Elsevier Science B.V.. (2000)

Sasaki T：“最近重新评估低剂量领域辐射的影响。在“今日口腔颌面放射学”中”H.Fuchihata ed.，Elsevier Science B.V.（2000）

Takehito Sasaki: "Room temperature-induced apoptosis of Jurkat cells sensitive to both caspase-1 and caspase-3 inhibitors." Cancer Letters. 132. 7-16 (1998)

Takehito Sasaki：“室温诱导对 caspase-1 和 caspase-3 抑制剂敏感的 Jurkat 细胞凋亡。”