Tomazic V J, Sacasa C R, Loftus A, Suter C S, Elias G E
Department of Surgery, University of Maryland Hospital, Baltimore 21201.
Clin Exp Metastasis. 1988 Jan-Feb;6(1):17-25. doi: 10.1007/BF01580403.
The biological activities of two thymic factors, serum thymic factor thymulin normally present in serum and thymosin alpha-1 (Ta-1) extracted from the thymus gland, have been studied. The effects of the factors on the growth of pulmonary metastases and survival of mice were evaluated in pathogen-free C3H/fSed males. Mice were injected i.v. with the single cell suspension of the syngeneic methylcholanthrene-induced fibrosarcoma. The treatment with thymulin and Ta-1 started two days after injection of 5 x 10(4) to 2 x 10(5) tumor cells per mouse. Different doses of the thymic factors were administered S.C. in sets of 5 daily injections through a period of 2 or 3 weeks. Numbers of tumor colonies in the lung were determined two weeks after the cell injection. Treatment with 0.1 micrograms Ta-1 per injection through the period of two or three weeks, prolonged the survival of tumor-injected mice. Similar effects were observed in mice treated with 0.01 microgram thymulin per injection. Numbers of tumor colonies in lungs of these mice two weeks after the cell injection were also reduced in comparison with saline-treated controls. These findings correlated with prolonged survival time of identically treated mice. The effectiveness of thymic factors in reducing tumor growth was dependent on the tumour load. In addition, the effects induced by Ta-1 persisted longer than observed in thymulin-treated mice. Mice challenged 150 days after the primary tumor cell injection and treatment with Ta-1 demonstrated increased resistance to tumor, while mice treated with other factors behaved as saline-treated controls. The results indicate that both factors exert beneficial effects against tumor growth, although mode of action for each factor may be different.
对两种胸腺因子的生物学活性进行了研究，这两种因子分别是血清中正常存在的血清胸腺因子胸腺素以及从胸腺中提取的胸腺素α-1（Ta-1）。在无特定病原体的C3H/fSed雄性小鼠中评估了这些因子对肺转移瘤生长和小鼠存活的影响。给小鼠静脉注射同基因甲基胆蒽诱导的纤维肉瘤单细胞悬液。在每只小鼠注射5×10⁴至2×10⁵个肿瘤细胞两天后开始用胸腺素和Ta-1进行治疗。通过皮下注射不同剂量的胸腺因子，每天注射5次，持续2或3周。在细胞注射两周后测定肺中的肿瘤集落数量。在两周或三周的时间内每次注射0.1微克Ta-1进行治疗，可延长接种肿瘤小鼠的存活时间。在每次注射0.01微克胸腺素治疗的小鼠中也观察到了类似的效果。与生理盐水处理的对照组相比，这些小鼠在细胞注射两周后肺中的肿瘤集落数量也减少了。这些发现与相同处理小鼠的存活时间延长相关。胸腺因子减少肿瘤生长的有效性取决于肿瘤负荷。此外，Ta-1诱导的效果比胸腺素治疗的小鼠持续时间更长。在原发性肿瘤细胞注射和用Ta-1治疗150天后受到攻击的小鼠表现出对肿瘤的抵抗力增强，而用其他因子治疗的小鼠表现得与生理盐水处理的对照组一样。结果表明，尽管每种因子的作用方式可能不同，但这两种因子对肿瘤生长均发挥有益作用。
