Objective    To explore the effect of mouse macrophages with different activated phenotype on the proliferation and invasion of mouse Lewis lung carcinoma (LLC) cells.     Methods    RAW264.7 macrophages were treated by mr IFN-γ+LPS or mr IL-4 for 24 h respectively

then identified by RT-PCR to detect iNOS--the marker of classically activated macrophages

(caMphi) and Fizz1--the marker of alternatively activated macrophages (aaMphi). Based on the co-culture Transwell systems of activated macrophages (4 groups: blank control group

caMphi group

aaMphi group and RAW264.7 group) and LLC cells

cell growth curves of LLC cells were drawn

vascular endothelial growth factor-C (VEGF-C) expressions of LLC cells were detected by immunocytochemistry

and NO concentrations of co-culture fluid supernatant were determined by nitrate reductase method.

3

H-TdR incorporation and Transwell invasion model were used to observe the effect of activated macrophages on the proliferation and invasion of LLC cells

respectively.     Results    Mouse caMphi and aaMphi models were established successfully. Among the 4 co-culture groups

the growth of LLC cells and VEGF-C expression were the fastest and strongest in aaMphi group

secondary in RAW264.7 group; NO concentration was high in caMphi group

but no NO was determined in the other 3 groups. The proliferation and invasion of LLC cells were promoted most in aaMphi group

then in RAW264.7 group

but inhibited in caMphi group.     Conclusion    aaMphi can promote the proliferation and invasion of LLC cells by the promotion of VEGF-C expression. caMphi can inhibit them by high level production of NO. After co-culture with LLC cells

the function of RAW264.7 cells may be polarized toward that of aaMphi.