Garte S J, Currie D D, Troll W
Cancer Res. 1987 Jun 15;47(12):3159-62.
The protease inhibitors antipain, leupeptin, alpha 1-antitrypsin, and epsilon-aminocaproic acid were found to inhibit transformation of NIH3T3 cells after transfection with an activated H-ras oncogene. Inhibition of focus formation by protease inhibitors was concentration dependent and maximal at 50% of control values. Transfection of a gene for neomycin resistance was not affected by protease inhibitors. Antipain was inactive if present only during the first 2 days of the gene transfer protocol or only during the final 10 days of the experiment. However, the full effect was observed when antipain was added at the subculture step on day 3 and during the subsequent cell proliferation. If cells were not subcultured, the yield of the foci per microgram of DNA was sharply reduced and addition of antipain did not further suppress the transformation rate. Subculture of NIH3T3 cells 3 days after transfection at lower cell densities resulted in higher transformation efficiency. The results suggest that transformation of NIH3T3 cells by a single mutated oncogene may involve multiple stages including cell proliferation and that part of this process is susceptible to inhibition by protease inhibitors.
已发现蛋白酶抑制剂抗痛素、亮抑蛋白酶肽、α1-抗胰蛋白酶和ε-氨基己酸在转染活化的H-ras癌基因后可抑制NIH3T3细胞的转化。蛋白酶抑制剂对集落形成的抑制作用呈浓度依赖性，在对照值的50%时达到最大抑制效果。新霉素抗性基因的转染不受蛋白酶抑制剂的影响。如果抗痛素仅在基因转移方案的前2天或仅在实验的最后10天存在，则无活性。然而，当在第3天的传代培养步骤及随后的细胞增殖过程中添加抗痛素时，可观察到完全的抑制效果。如果细胞不传代培养，每微克DNA的集落产量会急剧降低，添加抗痛素也不会进一步抑制转化速率。转染后3天以较低细胞密度对NIH3T3细胞进行传代培养可获得更高的转化效率。结果表明，单个突变癌基因对NIH3T3细胞的转化可能涉及多个阶段，包括细胞增殖，且该过程的一部分易受蛋白酶抑制剂的抑制。
