Novel Anti-Cancer Drug Composed of Human Proteins

1.哺乳动物胰腺核糖核酸酶（RNase）通过二硫键与人表皮生长因子（EGF）化学偶联。人表皮生长因子-乳腺RNA酶偶联物对表皮生长因子受体缺陷型小细胞肺癌细胞系H69没有细胞毒性作用。但该偶联物显示出对鳞状细胞癌细胞系和乳腺癌细胞系的剂量依赖性细胞毒性，并且偶联物的细胞毒性与各细胞系的EGFR表达水平正相关。EGF和RNase的未结合混合物对任何细胞系的作用均不比单独的RNase大。将重组人核糖核酸酶1（RNase 1）与重组人表皮生长因子（EGF）化学连接，构建了EGF-RNase偶联物，并对EGF受体过表达细胞株进行了细胞毒实验。EGF和RNase的未结合混合物没有比单独的RNase更大的效果。该偶联物对EGF受体缺陷型小细胞肺癌细胞没有可检测的细胞毒性.将编码人胰腺RNA酶1的基因与编码人EGF或人IL-2的基因融合。重组人源蛋白在大肠杆菌中得到表达，并以包涵体形式表达、溶解、体外复性、恢复活性和纯化. RNase-EGF偶联物对几种鳞状细胞癌细胞系具有细胞毒性，EGF受体数量依赖性。游离EGF和游离RNase 1的混合物没有比单独的RNase 1更大的作用，并且对于受体缺陷的对照细胞没有检测到细胞毒性。

1. Mammalian pancreatic robonuclease (RNase) was conjugated chemically via a disulfide bond to human epidermal growth factor (EGF). The human EGF-mam malian RNase conjugate had no cytotoxic effect against the EGFreceptor-deficient small-cell lung cancer cell line H69. But this conjugate showed dose-dependent cytotoxicity against squamous carcinoma cell lines and breast cancer cell lines and the cytotoxicity of the conjugate correlated positively with the level of expression of EGFR by each cell line. An unconjugated mixture of EGF and RNase had no greater effect than RNase alone on any cell lines.2. Recombinant human RNase 1 (RNase1) was chemically linked to recombinant human EGF.The EGF-RNase conjugate showed dose-dependent cytotoxicity for EGF receptor-overexpressing cell lines. An unconjugated mixture of EGF and RNase had no greater effect than RNase alone. the conjugate showed no detectable cytotoxicity atainst EGF receptor-deficient small cell lung cancer cell.3. The gene coding for human pancreatic RNase1, was fused with a gene coding for human EGF or human IL-2. These DNA were expressed in E.Coli, efficient amounts of the recombinant human protein were produced in inclusion bodies, solubilized, refolded in vitro, regained activity and purified to homogeneity.4. The RNase-EGF conjugate was cytotoxic, EGF-receptor number dependently, to several squamous carcinoma cell lines. A mixture of free EGF and free RNase1 had no greater effect than RNase1 alone and no cytotoxicity was detectable for receptor deficient control cells.