Fig. 4
Downregulation of EMT, the Akt/p38 signaling cascades, and cancer cell invasion by purified exosomes and the exosomal PTEN level in recipient cancer cells. 344SQ cells were treated with exosomes isolated from RAW conditioned medium with (ExoApoSQ CM) or without (ExoCM) apoptotic 344SQ cells, in the presence of TGF-β1 (10 ng/ml) for the indicated times, as shown in (a–d). a–c Immunoblot analysis of indicated proteins in 344SQ cell lysates after incubation with exosomes. d Confocal microscopic images of 3D acini were taken 10 days after cell seeding. The normal acini of 344SQ cells were grown in 3D Matrigel containing exosomes and stained with anti-β-catenin (green) and DAPI. Scale bars: 20 μm. 344SQ cells were treated with purified exosomes from the culture medium of apoptotic cancer cell-stimulated RAW 264.7 cells transfected with or without two siRNAs for PTEN (#1 and #2 siPTEN) for the indicated times, as shown in (e, f). The immunoblot analysis of indicated proteins in purified exosomes is shown in (e), that in 344SQ cell lysates after treatment with purified exosomes is shown in (f). g qPCR analysis of PTEN mRNA in 344SQ cells 12 h after treatment with exosomes isolated from RAW CM with (ExoApoSQ CM) or without (ExoCM) apoptotic 344SQ cells. NS not significant; **P < 0.01. Data are from one experiment representative of three independent experiments with similar results are shown in (a–e, f upper panel), or data from three independent experiments (mean ± s.e.m.) are shown in (f lower panel) and (g)
