Roles of Free Radicals Produced under Hypoxic Condition on the Tumor Development and Progression

在本研究中，我们的目的是验证在缺血再灌注环境中内在产生的自由基是常见癌症的致病因素。为此，我们使用了几种正常和癌前培养细胞系，如FPCK-1-1（人，结肠腺瘤细胞）、IEC 6（大鼠，永生化肠细胞）、NIH 3 T3（小鼠，永生化成纤维细胞）、Balb 3 T3（小鼠，永生化成纤维细胞）和QR-32（小鼠，癌前纤维肉瘤）。在培养条件下，我们还利用常氧（21%O_2）和低氧（1%O_2）培养箱来创造一个人工缺血-再灌注环境。通过使用这些材料，结果表明：1）正常或癌前培养细胞在缺氧条件下培养至常氧条件下，产生大量的自由基; 2）小鼠永生化成纤维细胞在常氧和缺氧条件下反复培养后，可发生自发性致瘤性转化。导致了肿瘤的转化

In the present study, we aimed to verify that intrinsically produced free radicals in the ischemia-reperfusion environment are a causative factor of common cancers. For this purpose, we used several normal and pre-malignant cultured cell lines such as FPCK-1-1 (human, colonic adenoma cell), IEC 6 (rat, immortalized intestinal cell), NIH3T3 (mouse, immortalized fibroblast), Balb3T3 (mouse, immortalized fibroblast) and QR-32 (mouse, pre-malignant fibrosarcoma). We also utilized normoxic (21% O_2) and hypoxic (1% O_2) culture chambers to create an artificial environment of ischemia-reperfusion in the culture condition. By using those materials, we obtained the following results.1)A large amount of free radicals were generated in the normal or pre-malignant cultured cells after the cells were transferred to normoxic condition from hypoxic condition.2)Spontaneous tumorigenic conversion was observed in the immortalized mouse fibroblast cell lines after repeatedly cultured in normoxic and hypoxic conditions.We are now determining the gene(s) responsible for the tumorigenic conversion.