[In vivo metastasis of human tumor transplant in T and NK cell immune-deficient mice].

Beige-nude mice with combined T and NK cell deficiency were produced by introducing "nu" gene into the beige mice of C57BL/6 background. The beige-nude mice were characterized by morphological features, level and activity of the NK cell in spleen and peripheral blood. NK cell level of the beige-nude mice was higher than the beige mice and similar to the ordinary nude mice though its NK cell activity was markedly lower than the nude mice. Human lung adenocarcinoma (PAa) was transplanted subcutaneously to the beige-nude mice and nude mice of BALB/cA background. No metastasis was found in BALB/cA nude mice (0/7), while in beige-nude mice, spontaneous lymph node metastasis rate was 36.3% (4/11). It should be noted that the transplanted PAa metastasized to lungs, which had never been seen in BALB/cA nude mice in previous experiments. The increase of metastatic rate is correlated with the relative low NK cell activity of the beige-nude mice. Our observation is that the beige-nude mice could be a suitable experimental model for in vivo study on metastatic behavior of the human tumors.