Cinatl J, Cinatl J, Kotchetkov R, Matousek J, Woodcock B G, Koehl U, Vogel J U, Kornhuber B, Schwabe D
Institute of Medical Virology, Center of Hygiene, Frankfurt am Main, Germany.
Anticancer Res. 2000 Mar-Apr;20(2A):853-9.
Bovine seminal ribonuclease (BS-RNase) exerts selective cytotoxicity toward different types of tumor cells. In the present study, we tested the effects of BS-RNase on cultured neuroblastoma (NB) cells resistant to chemotherapeutic agents. The selectivity of the antitumoral activity of BS-RNase was evaluated using cultures of CD34+ hematopoietic stem cells.
Human NB cell lines including IMR-32, UKF-NB-2 and UKF-NB-3 were selected for resistance against vincristine, doxorubicin or cisplatin by exposure to increasing concentrations of the respective drug. The cytotoxicity of the drugs to NB cells was evaluated using a clonogenic assay in a methylcellulose medium. Peripheral blood progenitor cells were obtained from adult healthy donors by positive selection using specific anti-CD34+ antibodies. The toxicity of BS-RNase to CD34+ cells was assessed in the direct clonogenic assay using methylcellulose medium or in ex vivo expansion culture supplemented with hematopoietic growth factors.
In the clonogenic assay it was shown that BS-RNase completely inhibits growth of both parental NB cells and their sublines resistant to chemotherapeutic drugs at concentrations (up to 50 micrograms/ml) which have no significant influence on the growth of colony-forming units, granulocyte macrophage and erythroid burst-forming units. Moreover, BS-RNase had no effect on the ex vivo expansion of total hematopoietic cells or of colony-forming cells from CD34+ progenitors.
BS-RNase is a highly efficient agent against NB cells resistant to chemotherapeutic drugs. The lack of toxicity to hematopoietic progenitor cells suggests that BS-RNase is also likely to have tolerable hematopoietic toxicity.
牛精核糖核酸酶（BS - RNase）对不同类型的肿瘤细胞具有选择性细胞毒性。在本研究中，我们测试了BS - RNase对化疗耐药的培养神经母细胞瘤（NB）细胞的作用。使用CD34 +造血干细胞培养物评估BS - RNase抗肿瘤活性的选择性。
通过暴露于浓度递增的相应药物，选择包括IMR - 32、UKF - NB - 2和UKF - NB - 3在内的人NB细胞系，使其对长春新碱、阿霉素或顺铂产生耐药性。使用甲基纤维素培养基中的克隆形成试验评估药物对NB细胞的细胞毒性。通过使用特异性抗CD34 +抗体进行阳性选择，从成年健康供体中获得外周血祖细胞。在使用甲基纤维素培养基的直接克隆形成试验中或在补充造血生长因子的体外扩增培养中评估BS - RNase对CD34 +细胞的毒性。
在克隆形成试验中表明，在对集落形成单位、粒细胞巨噬细胞和红系爆式集落形成单位的生长没有显著影响的浓度（高达50微克/毫升）下，BS - RNase完全抑制亲代NB细胞及其化疗耐药亚系的生长。此外，BS - RNase对全造血细胞或CD34 +祖细胞的集落形成细胞的体外扩增没有影响。
BS - RNase是一种针对化疗耐药NB细胞的高效药物。对造血祖细胞缺乏毒性表明BS - RNase也可能具有可耐受的造血毒性。
