Study of the biological characteristics and antitumor activity of recombinant IFN-α-2B-BCG / 中华微生物学和免疫学杂志

ABSTRACT

Objective To investigate the biological characteristics of recombinant hIFN-α-2B-BCG and its direct effect to bladder tumor cells in vitro. Methods BCG and recombinant BCG(rBCG) wild-type growth and morphology were compared. After 10 generations, hIFN-α-2B content was analyzed by ELISA, of bacteria in vivo and in vitro. The effects of rBCG on bladder cancer cells EJ, MB49, were detected by elec-tron microscopy and cell inhibitory rate from MTT. Results The normal BCG and rBCG had no significant difference in growth phase. They were both positive for acid-fast stain, maintaining the characteristics of cell's connection. While rBCG slightly larger than normal BCG, no else abnormality was obvious between them. IFN-α-2B was 997.2 pg/ml in secretions, 99.3 pg. In bacteria in vivo, 990.3 pg/ml in 10th genera-tion's sections, of rBCG. Compared with 1st generation, rBCG had no significant differences in morphology and interferon expression. Normal BCG and rBCG both had, anti-proliferation directly on bladder tumor cell in vitro, the rBCG is most effective in all. After rBCG cultivated with bladder tumor cell together, tumor cell's slow proliferation, detach, quantity decreasing and death were observed under microscope. Different degeneration in degree on most of tumor cells, disorganization on organelle, aggregation on chromatin, pyc-nosis on nucleolus, and cytoplasm lysis were on tumor cell under transmission electro microscopy. MTT as-say showed rBCG inhibited the proliferation of bladder caner cell and more active than normal BCG. Conclu-sion These results suggest that the rBCG have the same characteristics in growth phase as normal BCG, and stable properties in interferon expression and morphology by generations, rBCG has more anti-tumor effects in vitro than normal BCG.