Gabrilovac J, Radacić M, Osmak M, Boranić M
Ruder Bossković Institute, Department of Experimental Biology and Medicine, Zagreb, Yugoslavia.
Cancer Immunol Immunother. 1990;32(1):45-50. doi: 10.1007/BF01741723.
C57B1 and CBA mice of different ages (6, 12, 26 or 35 weeks) received intramuscular inocula of melanoma B16 or mammary adenocarcinoma (MCa), respectively. Median survival time was shorter, the younger the recipients. Tumor enlargement was correspondingly retarded in older mice. This was associated with decrease of natural killer (NK) activity in the spleens. However, the cytotoxicity against fresh syngeneic tumor cells, increased with age in CBA mice. In contrast to the growth of intramuscular tumors, the ability of intravenously injected B16 or MCa cells to form nodules in the lungs was significantly superior in old animals (35 weeks or more), with low levels of NK activity, than in young ones (6 weeks) with high levels of NK activity. Stimulation of NK activity by poly(I).poly(C) reduced the number of MCa colonies by 50% in the lungs of old mice, but had no effect on colony-forming ability in young animals. The observed association of tumor growth with age and NK activity levels may reflect (a) an interplay of tumor-inhibiting and tumor-promoting effects of NK cells, changing with age, and (b) the accessibility of tumor cells, inoculated intramuscularly or captured in the lungs, to these influences.
不同年龄（6周、12周、26周或35周）的C57B1和CBA小鼠分别接受了黑色素瘤B16或乳腺腺癌（MCa）的肌肉注射接种。受体年龄越小，中位生存时间越短。老年小鼠的肿瘤生长相应减缓。这与脾脏中自然杀伤（NK）活性的降低有关。然而，CBA小鼠对新鲜同基因肿瘤细胞的细胞毒性随年龄增长而增加。与肌肉内肿瘤的生长情况相反，静脉注射的B16或MCa细胞在肺部形成结节的能力在NK活性水平低的老年动物（35周及以上）中明显优于NK活性水平高的幼年动物（6周）。用聚肌苷酸-聚胞苷酸（poly(I).poly(C)）刺激NK活性可使老年小鼠肺部的MCa集落数量减少50%，但对幼年动物的集落形成能力没有影响。观察到的肿瘤生长与年龄和NK活性水平之间的关联可能反映了：（a）NK细胞的肿瘤抑制和肿瘤促进作用之间的相互作用，这种作用随年龄变化；（b）肌肉内接种或在肺部捕获的肿瘤细胞受这些影响的易感性。
