Figure 2. Galectin-3^−/− mice are more resistant to methylcholanthrene induced sarcomas development.

Wild type and galectin-3^−/− mice were given two subcutaneous doses of 3-methylcholanthrene, a known chemical carcinogen. The development of tumors was followed weekly after the second dose. Analysis of the disease-free survival curves from both wild type (n = 23 animals) and galectin-3^−/− mice (n = 17 animals) showed that wild type mice developed sarcomas faster than galectin-3^−/− animals (A) (Log-rank test, p = 0.04). At necropsy, tumors were maintained in culture conditions, allowing for the establishment of sarcoma derived cell lines. Galectin-3 accumulation was analyzed in protein extracts from established cell lines from both wild type (S11 and S12) and galectin-3^−/− mice (Σ12) by western blotting. S11 and S12 cells, but not Σ12 cells, expressed galectin-3. While S12 cells maintained high expression of galectin-3 in all passages analyzed, only early (e, passage number<15), but not late (l, passage number>15) passages of S11 expressed galectin-3. Note that part of the molecules produced were further processed rendering the lower molecular weight form of the lectin, which appears as a 30 kDa band (B). The expression of galectin-3 on S11 and Σ12 cell surface was analyzed by flow cytometry. S11 cells display at least part of its galectin-3 content on the cell surface (C).