Figure 5

Progression of transplanted mammary tumors in wild type and NG2 null mice. A, B. 1 mm³ fragments of wild type MMTV-PyMT tumors were transplanted to mammary fat pad sites in the #4 glands of wild type (wt) and NG2 null (ko) recipients. Each of the recipients (ten wild type and ten NG2 null females) received two transplants, yielding 20 potential tumor sites in each genotype. Trials 1 and 2 utilized four-month (panel A) and two-month old recipients (panel B), respectively. Data are plotted as the % sites with palpable masses as a function of time after transplantation. C, D. Orthotopic allografts of Py8119 (panel C) and Py230 tumor cells (panel D) were prepared by injecting 10⁶ cells into each of four sites in the #2 and #4 mammary fat pads of wild type and NG2 null recipients (six females of each genotype; 24 potential tumor sites for each genotype). Data are plotted as the % sites with palpable masses as a function of time after transplantation. Indicated P values were obtained via Wilcoxon signed rank tests. MMTV-PyMT, mammary tumor virus-driven polyoma middle T; NG2, nerve-glial antigen 2.