Project description:Background: Human breast cancer is a heterogeneous disease consisting of multiple molecular subtypes. Genetically engineered mouse models (GEMMs) are useful resources for studying breast cancers in vivo under genetically controlled and immune competent conditions. Identifying murine models with conserved human tumor features will facilitate etiology determinations, highlight the effects of mutations on pathway activation, and improve preclinical drug validation. Results: Transcriptomic profiles of 27 murine models of mammary carcinoma and normal mammary tissue were determined using gene expression microarrays. Hierarchical clustering analysis identified 17 distinct murine subtypes (classes). Across species analyses using three independent human breast cancer datasets identified eight murine classes that represent specific human breast cancer subtypes. Multiple models were associated with human basal-like tumors including TgC3(1)-Tag, TgWap-Myc, and Trp53-/-. Interestingly, the TgWAPCre-Etv6 model mimicked the HER2-enriched subtype, a group of human tumors without a murine counterpart in previous comparative studies. Gene signature analysis identified hundreds of commonly expressed pathways between linked mouse and human subtypes, highlighting potentially common genetic drivers of tumorigenesis and candidate pathways for therapeutic intervention. Conclusion: This study consolidates murine models of breast carcinoma into the largest comprehensive transcriptomic dataset to date to identify human-mouse disease subtype counterparts. This approach illustrates the value of comparisons between species to identify murine models that faithfully mimic the human condition and indicates that multiple GEMMs are needed to represent the diversity of human breast cancers. These trans-species associations should guide model selection during preclinical study design to ensure appropriate representatives of the human disease subtypes are used. Keywords: breast cancer, comparative genomics, genetically engineered mouse models, and molecular pathway signatures reference x sample
Project description:Background: Human breast cancer is a heterogeneous disease consisting of multiple molecular subtypes. Genetically engineered mouse models (GEMMs) are useful resources for studying breast cancers in vivo under genetically controlled and immune competent conditions. Identifying murine models with conserved human tumor features will facilitate etiology determinations, highlight the effects of mutations on pathway activation, and improve preclinical drug validation. Results: Transcriptomic profiles of 27 murine models of mammary carcinoma and normal mammary tissue were determined using gene expression microarrays. Hierarchical clustering analysis identified 17 distinct murine subtypes (classes). Across species analyses using three independent human breast cancer datasets identified eight murine classes that represent specific human breast cancer subtypes. Multiple models were associated with human basal-like tumors including TgC3(1)-Tag, TgWap-Myc, and Trp53-/-. Interestingly, the TgWAPCre-Etv6 model mimicked the HER2-enriched subtype, a group of human tumors without a murine counterpart in previous comparative studies. Gene signature analysis identified hundreds of commonly expressed pathways between linked mouse and human subtypes, highlighting potentially common genetic drivers of tumorigenesis and candidate pathways for therapeutic intervention. Conclusion: This study consolidates murine models of breast carcinoma into the largest comprehensive transcriptomic dataset to date to identify human-mouse disease subtype counterparts. This approach illustrates the value of comparisons between species to identify murine models that faithfully mimic the human condition and indicates that multiple GEMMs are needed to represent the diversity of human breast cancers. These trans-species associations should guide model selection during preclinical study design to ensure appropriate representatives of the human disease subtypes are used. Keywords: breast cancer, comparative genomics, genetically engineered mouse models, and molecular pathway signatures
Project description:This study identifies progression in breast ductal carcinoma in situ (DCIS) as it progresses towards triple negative invasive breast cancer (TNBC). Bulk DNA arrayCGH was performed on the C3Tag genetically engineered mouse model that forms human breast-like DCIS and TNBC.
Project description:Activation of the tyrosine kinase c-Src promotes breast cancer progression and poor outcome, yet the underlying mechanisms are incompletely understood. Here, we show that deleting c-Src abrogates the activity of Forkhead Box M1 (FOXM1), a master transcriptional regulator of the cell cycle, in a genetically engineered model mimicking the Luminal B molecular subtype of breast cancer. By phosphorylating it on two tyrosine residues, c-Src stimulates the nuclear localization of FOXM1 and the expression of its target genes, including key regulators of G2-M cell cycle progression as well as c-Src itself. This positive feedback loop drives proliferation in genetically engineered and patient-derived models of Luminal B-like breast cancer. Targeting this mechanism, including through novel compounds that destabilize the FOXM1 protein, induces G2-M cell cycle arrest and apoptosis, blocking tumor progression and impairing metastasis. We identify positive correlation of FOXM1 and c-Src expression in human breast cancer and show that the expression of FOXM1 target genes predicts poor outcome and associates with the Luminal B subtype, which responds poorly to approved therapies. These findings indicate that a regulatory network centered on c-Src and FOXM1 is a targetable vulnerability in aggressive luminal breast cancers.
Project description:Pancreatic neuroendocrine tumor (PanNET) is relatively infrequent but is nevertheless metastatic. Seeking to extend a new paradigm of personalized medicine, we performed an integrative analysis of transcriptomic (mRNA and microRNA) and mutational profiles and defined three clinically relevant human PanNET subtypes. Importantly, cross-species analysis revealed two of these three subtypes in a well-characterized, genetically engineered mouse model (RIP1-Tag2) of PanNET and its cell lines. Each subtype share similarities to distinct cell types in pancreatic neuroendocrine development, features are reflected in their metabolic profiles. Subtype-specific molecular signatures metabolites are proposed to identify these subtypes. Gene expression data from different stages of RIP1-TAG2 genetically engineered PanNET mouse model RT2 mouse PanNET tumors, liver metastases, normal, hyperplastic, and angiogenic islets were dissected out or isolated. RNA was extracted and hybridized on Affymetrix GeneChip Mouse Gene 1.0 ST arrays. The CEL files were processed using aroma.affymetrix.
Project description:We explored potential bypass mechanisms to PI3K/mTOR-directed therapy in KRAS mutant CRC models, utilizing genetically engineered mouse models (GEMM) to generate acquired resistance to the targeted dual PI3K/mTOR small molecule inhibitor PF-04691502. Transcriptomic analysis revealed a dynamic stem-like progenitor signature which was increased in the presence of drug pressure.
Project description:A bank of human breast tumor xenografts was established by serial passage of primary breast tumor fragments in the cleared mammary fat pads of immuno-compromised NOD-SCID-IL2Rgammac–/– mice. The 15 expression profiles from five different tumors were classified using the ClaNC method [1]. The training data set consisted of 94 samples from Herschkowitz et al. [2]; class labels were based on tumor subtype (Basal-like, Luminal A, Luminal B, Claudin-low, HER2+/ER- and Normal breast-like). [1] Dabney AR (2005) Classification of microarrays to nearest centroids. Bioinformatics 21:4148-4154. [2] Herschkowitz JI, et al. (2007) Identification of conserved gene expression features between murine mammary carcinoma models and human breast tumors. Genome Biol 8:R76. Total RNA obtained from xenograft tumors from 5 different patients have been profiled in triplicate on the Illumina HT-12 BeadChip platform.
Project description:A bank of human breast tumor xenografts was established by serial passage of primary breast tumor fragments in the cleared mammary fat pads of immuno-compromised NOD-SCID-IL2Rgammac–/– mice. The 15 expression profiles from five different tumors were classified using the ClaNC method [1]. The training data set consisted of 94 samples from Herschkowitz et al. [2]; class labels were based on tumor subtype (Basal-like, Luminal A, Luminal B, Claudin-low, HER2+/ER- and Normal breast-like). [1] Dabney AR (2005) Classification of microarrays to nearest centroids. Bioinformatics 21:4148-4154. [2] Herschkowitz JI, et al. (2007) Identification of conserved gene expression features between murine mammary carcinoma models and human breast tumors. Genome Biol 8:R76.
Project description:Defective Hippo/YAP signaling in the liver results in tissue overgrowth and development of hepatocellular carcinoma (HCC). Here, we uncover mechanisms of YAP-mediated hepatocyte reprogramming and HCC pathogenesis. We show that YAP functions as a rheostat maintaining metabolic specialization, differentiation and quiescence within the hepatocyte compartment. Importantly, treatment with siRNA-lipid nanoparticles (siRNA-LNPs) targeting YAP restores hepatocyte differentiation and causes pronounced tumor regression in a genetically engineered mouse HCC model (mice with liver-specific Mst1/Mst2 double knockout). Furthermore, YAP targets are enriched in an aggressive human HCC subtype characterized by a proliferative signature and absence of CTNNB1 mutations. Thus, our work reveals Hippo signaling as a key regulator of positional identity of hepatocytes, supports targeting YAP using siRNA-LNPs as a paradigm of differentiation-based therapy, and identifies an HCC subtype potentially responsive to this approach. Mice with liver-specific Mst1/Mst2 double-knockout (Adeno-Cre injected Mst1-/-; Mst2Flox/Flox mice) were monitored for the formation of HCC by ultrasound imaging. Animals were then randomized to be treated by intravenous injection of either siYap-LNPs or siLuciferase-LNPs for a period of 9 days.