Figure 4.

COX-2 induces PGE₂ and IL-6 release in macrophages and regulates MMP-9 and EMT by activating Akt pathway in breast cancer cells. (A) The level of PGE₂ in MDMs or TAMs transfected with adenoviral COX-2 or siRNA COX-2 was detected by EIA. The experiments were performed thrice in triplicate. The data are presented as the mean ± SD. **p < 0.01. (B) The level of IL-6 in MDMs or TAMs transfected with adenoviral COX-2 or siRNA COX-2, or treated with PGE₂ (1 μM) was detected by ELISA. The experiments were performed thrice in triplicate. The data are presented as the mean ± SD. **p < 0.01. (C) Inhibiting Akt1 in breast cancer cells attenuated cell invasion induced by COX-2 in TAMs. Breast cancer cells transfected with adenoviral siRNA Akt1 or Akt1 were co-cultured with or without (Alone) TAMs transfected with adenoviral COX-2 or siRNA COX-2. The transwell invasion assay was then carried out as described before. (D) Inhibiting Akt1 resulted in the suppression of MMP-9 and snail in breast cancer cells co-cultured with COX-2⁺ TAMs. The expression of related proteins in breast cancer cells was detected by Western blot. β-actin was used as an internal loading control, and the blots shown are representative of six independent experiments.