RESUMO
OBJECTIVE: To investigate effects of anti-dsDNA autoantibodies on growth of tumor in vitro and in vivo. METHODS: BALB/c mice were inoculated with inactivated tumor cells and challenged s.c. with SP 2/0 and Wehi 164 tumor cells four weeks after the last inoculation. The naïve mice were inoculated with SP 2/0 tumor cells immediately after incubating with sera derived from the immunized mice at week 6. Then the tumor size was examined. In vitro, the cytotoxicity of anti-dsDNA autoantibodies to tumor cells was analysed. Furthermore, apoptosis of SP 2/0 and Wehi 164 tumor cells induced by anti-dsDNA autoantibodies was examined by FACS. RESULTS: In vivo study showed that the growth of SP 2/0 and Wehi 164 tumors were inhibited in mice with anti-dsDNA autoantibodies, but not in mice lack of anti-dsDNA autoantibodies. In vitro, apoptosis of SP 2/0 and Wehi 164 tumor cells was induced when the tumor cells were incubated with the sera containing anti-dsDNA autoantibodies. Statistical analysis showed that the ability of anti-dsDNA autoantibodies to induce apoptosis of SP 2/0 and Wehi 164 tumor cells was significantly correlated with affinity (r = 0.990, P < 0.01 and r = 0.901, P < 0.05). CONCLUSION: Anti-dsDNA autoantibodies have inhibitory effect on tumor cells via inducing apoptosis.