Gαq deficiency dramatically diminishes the metastatic potential of circulating tumor cells. Quantitative analysis of experimental pulmonary metastases in wild-type and Gαq–/– mice following intravenous injection of 4.5 × 105 LLCGFP cells (A) or 8 × 104 B16-BL6 melanoma cells (B). The data shown represent the total number of surface pulmonary foci observed on all lung lobes for each mouse injected. The horizontal bars represent median values; P < .005 for each comparison using a Mann-Whitney U test. Gross appearance of pulmonary metastatic foci in animals injected with either LLCGFP cells (representative views in panels C-D) or B16-BL6 (representative views in panels E-F) tumor cells. Note that the number of LLCGFP tumor foci (detected based on GFP fluorescence) was dramatically higher in control mice (C) relative to Gαq–/– mice (D) but the size of individual lesions was similar. Images were obtained with a fluorescence-equipped Leica MZFL III stereomicroscope (Leica, Bannockburn, IL) equipped with an RTKE digital camera (RTKE Diagnostics, Sterling Heights, MI). SPOT RT software v. 3.5 was used to acquire images (RTKE Diagnostics). Similarly, high numbers of B16 melanoma lesions (detected based on melanin content) were seen in control mice (E) but not Gαq–/– mice (F).
