Fig. 5
IL-6/GP130 and leptin/OBR mediate adipocyte microenvironment-induced activation of PLOD2 and migration in breast cancer. a PLOD2 protein expression in MDA-MB-231 (MB-231) and MDA-MB-468 (MB-468) cells treated with the indicated IL-6 concentration for 0, 3, 6, or 12 h. b PLOD2 protein expression in MDA-MB-231 (MB-231) and MDA-MB-468 (MB-468) cells treated with the indicated concentration of leptin for 0, 24, 48, or 72 h. c MDA-MB-231 (MB-231) and MDA-MB-468 (MB-468) cells were monocultured or cocultured with adipocytes for a variety of times (0 to 72 h). Tumor cells were harvested to detect PLOD2 protein expression. d-e MDA-MB-231 (MB-231) and MDA-MB-468 (MB-468) cells were treated with the indicated concentration of IL-6 (d) or leptin (e) for 12 or 72 h and then harvested to conduct migration assays. Error bars represent means ± SD. Scale bars, 100 μm. f MDA-MB-231 cells were monocultured, cocultured with adipocytes, cocultured with adipocytes in the presence of a murine IL-6 blocking antibody, or cocultured with adipocytes following OBR depletion. After 3 days, these cells were harvested and centrifuged, and then the cells were gently resuspended in Cell Tracker™ blue (CMTPX). A total of 5 × 105 cells per 200 μL were then injected into the tail vein of each NOD SCID mouse. After 2 weeks, mice were sacrificed and lungs were isolated and sectioned for histological studies by fluorescence microscopy. Scale bars, 100 μm. Hematoxylin and eosin (H&E) staining of transverse sections of lungs from mice injected with MDA-MB-231 cells monocultured, cocultured with adipocytes, cocultured with adipocytes in the presence of a murine IL-6 blocking antibody, or cocultured with adipocytes following OBR depletion. Scale bars, 200 μm. Invasive lesions are indicated with arrows