Project description:Comparison of mammary tumors from 35 Brca1F/F;p53F/F, 62 Brca2F/F;p53F/F and 33 p53F/F mice. For each mouse, tumor DNA was hybridized with its spleen DNA as a reference.
Project description:Comparison of mammary tumors from 35 Brca1F/F;p53F/F, 62 Brca2F/F;p53F/F and 33 p53F/F mice. For each mouse, tumor DNA was hybridized with its spleen DNA as a reference.
Project description:To investigate the impact of combined Rb and p53 loss in mammary tumorigenesis, we used transgenic and viral approaches to delete Rb and p53 floxed alleles specifically in the mouse mammary epithelium. Although MMTV-Cre (NLST) targets stem/bi-potent progenitors in the mammary gland, a subset of MMTV-Cre:Rbf/f;p53f/f mice developed non-mammary tumors. Thus, freshly isolated primary mammary epithelial cells from these animals were transplanted into the mammary fat pads of immunodeficient mice and monitored for tumor formation. In addition, primary MECs were isolated from Cre-negative Rbf/f;p53f/f mice, infected with Ad-Cre followed by orthotopic transplantation. In all these cases, resulting tumors shared similar spindle-shape histology, expressed high levels of vimentin, a mesenchymal marker, but not E-cadherin, a luminal marker, and were classified as adeno-sacrcomatoid/spindle-cell/mesenchymal-like breast cancer. We used aCGH to detect copy number alterations associated with Rb/p53 deletion. Tumor DNAs from MMTV-Cre: Rbf/f;p53f/f and Ad-Cre: Rbf/f;p53f/f conditional mutant mice are being compared to pooled tail DNAs in order to identify common alterations associated with Rb/p53 deficient tumorigenesis
Project description:To investigate the impact of combined Rb and p53 loss in mammary tumorigenesis, we used transgenic and viral approaches to delete Rb and p53 floxed alleles specifically in the mouse mammary epithelium. Although MMTV-Cre (NLST) targets stem/bi-potent progenitors in the mammary gland, a subset of MMTV-Cre:Rbf/f;p53f/f mice developed non-mammary tumors. Thus, freshly isolated primary mammary epithelial cells from these animals were transplanted into the mammary fat pads of immunodeficient mice and monitored for tumor formation. In addition, primary MECs were isolated from Cre-negative Rbf/f;p53f/f mice, infected with Ad-Cre followed by orthotopic transplantation. In all these cases, resulting tumors shared similar spindle-shape histology, expressed high levels of vimentin, a mesenchymal marker, but not E-cadherin, a luminal marker, and were classified as adeno-sacrcomatoid/spindle-cell/mesenchymal-like breast cancer. We used aCGH to detect copy number alterations associated with Rb/p53 deletion.
Project description:Metastatic disease remains one of the most urgent clinical challenges accounting for over 90% of cancer-related deaths. Yet, the identification of novel therapeutic targets to fight or prevent metastatic disease has been hampered by the limited availability of clinically relevant mouse models of metastasis formation. To address this caveat, we developed a novel preclinical mouse model of spontaneous metastatic breast cancer that recapitulates the key biological events of the metastatic cascade and mimics the clinical course of metastatic disease in humans. Exploiting the conditional K14cre;CdhF/F;Trp53F/F mouse model of de novo mammary tumor formation, we orthotopically transplanted K14cre;CdhF/F;Trp53F/F derived mouse invasive lobular carcinoma (mILC) fragments into mammary glands of wild-type syngeneic hosts. Once recipient mammary tumors were established, we mimicked the clinical setting and performed a mastectomy. Following surgery, recipient mice eventually succumbed to wide-spread clinically overt metastatic disease in lymph nodes, lungs and gastrointestinal tract. Using aCGH analyses, we explored the relationship between the genomic profiles of mammary donor tumors and paired recipient outgrowths and observed a strong correlation, indicating that the genomic profile of the parental K14cre;CdhF/F;Trp53F/F mILC is highly conserved in recipient mammary tumors. To investigate the genomic relationship between recipient mammary tumors and their metastases, we examined the correlation structure of genomic profiles derived from paired sets of primary tumors and metastases. Genomic profiles of clonally-related recipient mammary tumors were highly conserved in local and distant metastases, indicating that few genomic alterations occur during transition from a primary tumor to a distant site. To more thoroughly examine potential site-specific genomic alterations, we constructed so-called ‘delta-profiles’ by calculating the difference between the genomic profile of a recipient mammary tumor and its paired lymph node- and lung metastasis. Site-specific recurrent alterations were not observed in lymph node nor lung metastases. Taken together, these data show that genomic profiles of metastases are highly similar to those of parental recipient tumors and that, if changes occurred, they did not recur in different independent samples.