Fig. 3: Overexpression of SLFN5 results in MET in mesenchymal-like BRCA cells and suppresses cell invasion in vitro and in vivo.

a Contrast-phase and fluorescent images of MDA-MB-231 cell lines stably transfected with a lentiviral control or the lentivirus carrying SLFN5. b WB analyses of SLFN5, E-cad and vimentin protein expression in MDA-MB-231 and BT549 cell lines stably transfected with a lentiviral control or the lentivirus carrying SLFN5. Protein band intensity is quantified and presented as the mean ± SD of three independent experiments. **P < 0.01. c Real-time PCR analyses of SLFN5, E-cad and vimentin protein expression in MDA-MB-231 and BT549 cell lines stably transfected with a lentiviral control or the lentivirus carrying SLFN5. d Immunofluorescence analysis of vimentin protein in MDA-MB-231 cell lines stably transfected with a lentiviral control or the lentivirus carrying SLFN5. Staining was performed with a vimentin antibody, which was followed by labelling with an Alexa Fluor 594-conjugated secondary antibody. The results were observed with laser confocal fluorescence microscope. DAPI staining revealed the nuclei. e Migration and invasion of MDA-MB-231 or BT549 cell lines stably transfected with a control or SLFN5 overexpression vector. Scale bar: 50 μm. f Chick CAM invasion analysis of MDA-MB-231 cell lines transfected with a control or SLFN5 overexpression vector. The white dotted lines indicate the position of the CAM. The white arrowheads indicate cells invading into the chick embryos. The double-headed arrow indicates invasion depth in the chick embryo. g Rescue experiments were performed using human SLFN5 shRNA viral particles or vector control viral particles. The results show that SLFN5 shRNA transfection partially rescued SLFN5 overexpression-induced E-cadherin and vimentin changes. Protein band intensity is quantified and is presented as the mean ± SD of three independent experiments. **P < 0.01.