TLR4 Ligand/H2O2 Enhances TGF-β1 Signaling to Induce Metastatic Potential of Non-Invasive Breast Cancer Cells by Activating Non-Smad Pathways
Figure 4
TGF-β1/H2O2/LPS down-regulates Nm23-H1 expression and up-regulates the expression of TGF-β receptors.
(A–C) MCF-7 cells were cultured in absence or presence of TGF-β1/H2O2/LPS (left) for the indicated time. Or the cells were cultured for 6 days in absence or presence of TGF-β1, H2O2, and LPS (right). The expression of TGFBR1 (A), and TGFBR2 (B) was detected by real-time RT-PCR. The expression of TβRI and TβRII was detected by Western blot after 6-d culture (C). (D) MCF-7 cells were cultured for 6 days in absence or presence of TGF-β1, H2O2, and LPS. The expression of Nm23-H1 and EDG2 was detected by Western blot. (E) MCF-7 cells were un-stimulated or stimulated for 6 days with TGF-β1/H2O2/LPS in absence or presence of wortmannin (WT, 40 nM), SB203580 (SB, 10 µM), PD98059 (PD, 10 µM), SP600125 (SP, 10 µM) or QNZ (40 nM). The expression of TGFBR1, TGFBR2 and NM23-H1 was detected by real-time RT-PCR. (F and G) Control MCF-7 cells and the MCF-7 cells expressing control shRNA or SNAI2 shRNA were untreated or treated with TGF-β1/H2O2/LPS for 6 days. SNAI2 expression was detected by Western blot (F). The expression of TGFBR2 was detected by real-time RT-PCR (G). P values, *P<0.05, **P<0.01.