Figure 4. Differential expression of Slc38a5 in mouse models of spontaneous mammary tumors representative of different major subtypes.

Tumors were collected from MMTV-Neu, MMTV-HRAS, and MMTV-PyMT female mice for RNA preparation. Mice used in the study did not go through breeding or pregnancy. Accordingly, virgin adult female wild type mice were used to collect mammary gland as the control. Since the age at which spontaneous tumors develop in the three mouse lines varies markedly (2–3 months of age for MMTV-PyMT mice whereas 8–10 months for the other two lines), we did not use age-matched wild type mice as controls. Instead, we used 3-month-old adult mice for this purpose. RNA was used for RT-PCR to monitor the expression pattern of several amino acid transporters that might be of relevance to tumor growth.