Figure 5

IgE causes increased melanoma tumor growth. ( A ) Effect of IgE on B16 melanoma tumor weight in C57BL/6J mice. Animals were treated with a single i.v. administration of saline (−IgE) or monoclonal anti-DNP IgE (750 ng/mouse; +IgE). Twenty four hours later, mice were s.c. inoculated with B16 melanoma cells (+B16) in one ear pinna and tumor weight was determined after four weeks of inoculation. Upper panel, a representative picture of vehicle or IgE-treated mice and vehicle or B16 cells-treated ear pinna. Lower panel, quantification of tumor weight. Results are shown as the mean ± SEM (n = 11-12). *, P < 0.05 versus + IgE mice. ( B ) Histological analysis of tissue biopsies. Ear pinna sections (2.5 μm) were stained with H&E (upper pictures) and TB (lower pictures). Blood vessels are indicated by arrows and MC by arrowheads. Photos are representative images from distinct mice (n = 2-4). Scale bar = 20 μm. ( C ) Quantification of MC by TB staining. Data are expressed as mean ± SEM from two sections per mouse, (n = 2-4). *, P < 0.05 versus –IgE + BL6. ( D ) quantification of blood vessels per ear pinna in tissue sections. Mean ± SEM (n = 3). *, P < 0.05 versus –IgE + BL6. ( E ) Effect of Bevacizumab on the IgE-dependent effects on melanoma tumor growth. Mice were treated with Bevacizumab (Beva; 10 mg/kg; s.c.) biweekly, starting 24 h after inoculation of melanoma cells. Ear pinna were removed and tumors were measured as in panel A. Data are expressed as the mean ± SEM (n = 4-11). *, P < 0.05 versus –IgE + BL6.