PinX1 inhibits breast cancer cells metastasis in vivo. (A) Left panel, Western blotting of PinX1 in there groups of Ctrl-MDA-MB-231 cell lines, PinX1OE-MDA-MB-231 cell lines and PinX1KD-MDA-MB-231 cell lines, which was selected with puromycin for 2 weeks after lentivirus infection. Right panel, without puromycin selection for 2 months, PinX1 expression levels were not changed in MDA-MB-231 stable cell lines. (B) H&E staining sections of lungs 2 months after injection of PinX1KD-MDA-MB-231 cell lines in BALB/c nude mouse through tail vein. Left panel, magnification × 100; right panel, magnification × 400. (C) Representative images of 10% buffered formalin fixed lungs with metastatic nodules 2 months after injection of Ctrl, PinX1OE and PinX1KD MDA-MB-231 stable cell lines. Arrows indicate metastatic nodules. (D) The number of lung metastatic nodules was counted under a dissecting microscope. Compared with the PinX1OE group, a statistically dramatic increase in the number of the lung metastases was seen in PinX1KD group, and these two groups also had significant diversity compared with Ctrl group respectively. Data are displayed with means ± SD from 10 mice in each group. ***, P < 0.001.