Kotchetkov R, Cinatl J, Krivtchik A A, Vogel J U, Matousek J, Pouckova P, Kornhuber B, Schwabe D, Cinatl J
Pediatric Clinic for Hematology and Oncology, University Clinics, Johann Wolfgang Goethe-University, Paul-Ehrlich Str. 40, D-60596 Frankfurt am Main, Germany.
Anticancer Res. 2001 Mar-Apr;21(2A):1035-42.
Anaplastic thyroid carcinoma is an aggressive solid tumor that fails to adequately respond to any known chemotherapeutic regimen. The development of effective chemotherapy agents would provide the best chance for long-term survival of patients.
The cytotoxic effects of bovine seminal ribonuclease (BS-RNase) against thyroid carcinoma cell lines with different degrees of differentiation in comparison to non-malignant cells, including human foreskin fibroblasts (HFF) and retinal pigment epithelial cells (RPE), were tested using the MTT dye reduction assay. Induction of apoptosis was demonstrated by annexin V assay and expression of proteins related to apoptosis was investigated by flow cytometry. The antitumoral in vivo effects of BS-RNase were assessed on established xenografts of anaplastic thyroid carcinoma cell line 8505C in nude mice using subcutaneous injections of BS-RNase (12.5 mg/kg once a day, on 20 consecutive days).
All the tumor cell lines exhibited marked sensitivity against BS-RNase in comparison to HFF and RPE cells. The greatest growth inhibition was seen in the 8505C line, while IC50 values for papillary (B-CPAP) and poorly-differentiated thyroid carcinoma cells were about 6-fold higher. The cytotoxic action of BS-RNase was associated with induction of apoptosis. Expressions of Fas and Fas-ligand were not influenced by BS-RNase completely, while the down-regulation of Bcl-2 in treated cells was observed. In vivo treatment induced significant tumor regression after the course of 20 consecutive days. No apparent toxic effects of BS-RNase toward non-malignant cells were observed during the in vivo treatment. After cessation of therapy (day 20) tumor volume continued to decrease and the tumor was no longer detectable after 30 days of treatment induction in all animals.
BS-RNase may have beneficial effects for treatment of aggressive anaplastic thyroid cancer.
间变性甲状腺癌是一种侵袭性实体瘤，对任何已知的化疗方案均反应不佳。开发有效的化疗药物将为患者的长期生存提供最佳机会。
使用MTT比色法检测牛精核糖核酸酶（BS-RNase）对不同分化程度的甲状腺癌细胞系以及非恶性细胞（包括人包皮成纤维细胞（HFF）和视网膜色素上皮细胞（RPE））的细胞毒性作用。通过膜联蛋白V检测法证实细胞凋亡的诱导，并通过流式细胞术研究与凋亡相关的蛋白质表达。通过皮下注射BS-RNase（12.5mg/kg，每天一次，连续20天）评估BS-RNase对裸鼠体内已建立的间变性甲状腺癌细胞系8505C异种移植瘤的抗肿瘤作用。
与HFF和RPE细胞相比，所有肿瘤细胞系对BS-RNase均表现出明显的敏感性。在8505C细胞系中观察到最大的生长抑制，而乳头状（B-CPAP）和低分化甲状腺癌细胞的IC50值约高6倍。BS-RNase的细胞毒性作用与细胞凋亡的诱导有关。Fas和Fas配体的表达未完全受BS-RNase影响，而在处理的细胞中观察到Bcl-2的下调。连续20天的体内治疗诱导了显著的肿瘤消退。在体内治疗期间未观察到BS-RNase对非恶性细胞有明显的毒性作用。停止治疗后（第20天），肿瘤体积持续减小，在所有动物诱导治疗30天后肿瘤不再可检测到。
BS-RNase可能对侵袭性间变性甲状腺癌的治疗有益。
