Biology Centre, Academy of Sciences of the Czech Republic v.v.i., Institute of Plant Molecular Biology, 370 05 Ceské Budejovice, Czech Republic.
Oncol Res. 2009;18(4):163-71. doi: 10.3727/096504009790217425.
Recombinant plant nucleases R-TBN1 and R-HBN1 were isolated to homogeneity and examined for their antitumor effects and cytotoxicity. Although antiproliferative effects of both recombinant nucleases were not significant on the ML-2 cell culture in vitro, the nucleases were strongly cytostatic in vivo after their administration intravenously as stabilized conjugates with polyethylene glycol (PEG). Recombinant nucleases were as effective against melanoma tumors as previously studied pine pollen (PN) and mung bean nucleases and their effects were reached at about 10 times lower concentrations compared to the use of bovine seminal RNase (BS-RNase). Because the recombinant nucleases R-HBN1 and R-TBN1 share only 67.4% amino acid identity and showed only partial immunochemical cross-reactivity, their similar anticancerogenic effects can be mainly explained by their catalytical similarity. Both recombinant nucleases showed lower degree of aspermatogenesis compared to BS-RNAse and PN nuclease. Unlike BS-RNase, aspermatogenesis induced by both recombinant nucleases could not be prevented by the homologous antibody complexes. Owing to relatively low cytotoxicity on the one hand, and high efficiency at low protein levels on the other, recombinant plant nucleases R-HBN1 and R-TBN1 appear to be stable biochemical agents that can be targeted as potential antitumor cytostatics.
重组植物核酸酶 R-TBN1 和 R-HBN1 被分离并达到均一性，并研究了它们的抗肿瘤作用和细胞毒性。尽管这两种重组核酸酶在体外 ML-2 细胞培养中没有明显的增殖抑制作用，但在静脉内给予它们与聚乙二醇（PEG）稳定缀合后，在体内具有强烈的细胞抑制作用。重组核酸酶在体内对黑色素瘤肿瘤的作用与先前研究的松花粉（PN）和绿豆核酸酶一样有效，并且其作用达到的浓度比使用牛精液 RNA 酶（BS-RNase）低约 10 倍。由于重组核酸酶 R-HBN1 和 R-TBN1 仅共享 67.4%的氨基酸同一性，并且仅表现出部分免疫化学交叉反应性，因此它们的相似抗癌作用主要可以用它们的催化相似性来解释。与 BS-RNAse 和 PN 核酸酶相比，两种重组核酸酶均显示出较低程度的精子发生抑制作用。与 BS-RNase 不同，由这两种重组核酸酶诱导的精子发生不能被同源抗体复合物预防。一方面由于细胞毒性相对较低，另一方面由于在低蛋白水平下的高效性，重组植物核酸酶 R-HBN1 和 R-TBN1 似乎是稳定的生化试剂，可以作为潜在的抗肿瘤细胞抑制剂进行靶向治疗。
