Mammary tumors induced by cyclin D1 and D1T286A metastasize in Dmp1+/− mice. A: Photomicrographs of mammary and metastatic tumors from one Dmp1+/−;MMTV-cyclin D1 mouse; tumor cells disseminated throughout the body to other organs, including the uterus and ovaries. Left panel: primary mammary tumor (arrows). Right panel: metastasis of tumor cells (arrows) throughout the abdomen. B: Representative images of immunostaining for H&E and cyclin D1 (red) in metastatic tumors in liver and ovary from Dmp1+/−;MMTV-cyclin D1 mice. High cyclin D1 expression was detected only in the tumor region but not adjacent normal tissues. Scale bars: 100 μm. N, normal; T, tumor. C: Real-time PCR analyses of human cyclin D1 transgene mRNA levels in normal organs of nontransgenic mice and mammary/metastatic tumors in Dmp1+/+;MMTV-cyclin D1 and Dmp1+/−;MMTV-cyclin D1 mice. Data were normalized against that of β-actin. MG, mammary gland; MMT, mouse mammary tumor; MT, metastatic tumor. D: Representative images of immunostaining for keratin 8 (red), keratin 14 (red) and Dmp1 (red) in primary mammary tumors and metastatic tumors from liver and ovary, respectively, of Dmp1+/−;MMTV-cyclin D1 mice. Nuclei were counterstained with hematoxylin after keratin 8 and keratin 14 staining. Scale bars: 100 μm.