Figure 3.

Tumor induction by HIV(ALSV)-PyMT. K19-tva transgenic mice were intraductally injected with 10³ IU of HIV(ALSV)-PyMT into the #2 to 4 mammary glands. (A) Kaplan-Meier curve showing tumor-free survival of infected mice (n = 13). One mouse died of natural causes and was censored at 9 months after injection. (B–C) Clonality analysis of HIV(ALSV)-PyMT virus-induced mammary tumors in K19-tva transgenic mice. Genomic DNA from 6 HIV(ALSV)-PyMT-induced tumors was subjected to Southern blot analysis after digestion with BamHI (B); molecular weights are indicated (left). A diagram of the HIV(ALSV)-PyMT provirus is shown (C); the radioactive probe was transcribed from the indicated 2.4-kb BamHI-EcoRV fragment. (D–G) Representative photomicrographs showing both papillary adenomyoepithelioma/carcinoma (D and E) and squamous cell-like (F) regions of tumors induced by HIV(ALSV)-PyMT. For comparison, an H&E-stained section from a tumor induced by RCAS-PyMT in a K19-tva transgenic mouse is shown (G); RCAS-PyMT-induced tumors were reminiscent of papillary adenomyoepithelioma/carcinomas. Scale bar, 50 µm.