Fig. 4

Reduced oncostatin M (OSM) expression results in fewer spontaneous lung metastases and lower total volume of lung metastases by magnetic resonance imaging (MRI). a Lung metastasis burden was quantified by qPCR. Mice bearing mammary 4T1.2-shOSM1 or 4T1.2-shOSM2 tumors had less metastasis to the lung than mice with 4T1.2-shLacZ tumors. b Mice bearing 4T1.2-shOSM2 tumors had less metastatic lesions in the lung as detected by MRI at the endpoint of the experiment than mice bearing parental 4T1.2 or control 4T1.2-shLacZ tumors. MRI quantification of lung metastatic volume (c) and total number of lung metastases (d) showed significantly higher volume and number of lung metastases in the 4T1.2- or 4T1.2-shLacZ-injected mice than the 4T1.2-shOSM2-injected mice (4T1.2, n = 6; 4T1.2-shLacZ, n = 7; 4T1.2-shOSM2, n = 7). Data are expressed as mean ± SEM. *p < 0.05 and **p < 0.01 by one-way analysis of variance with Tukey’s multiple comparisons test