Stem cell antigen-1 (Sca-1 or Ly6A) is a member of the Ly6 family of glycosyl phostidylinositol (GPI)-anchored cell surface proteins. To determine the potential mechanisms by which Sca-1 regulates cell migration, adhesion, and tumor development; we performed an Affymetrix mouse genome 430A 2.0 array on cDNA comparing shLuc and shSca-1 from cells grown in vitro.
Stem cell antigen-1 (sca-1) regulates mammary tumor development and cell migration.
Specimen part, Cell line
View SamplesBeyond demonstrating a critical role for progesterone receptor signaling in normal mammary epithelial proliferation, the progesterone receptor knockout mouse disclosed the progesterone receptor along with its effector pathways as key determinants of mammary neoplastic progression. Despite these advances, however, further progress in our mechanistic understanding of progesterones involvement in mammary morphogenesis and tumorigenesis is contingent upon defining the essential effector pathways responsible for transducing the progesterone signal into a mammary proliferative and/or pro-survival response. Toward this goal, a judiciously chosen acute progesterone treatment regimen together with microarray methods was applied to the mammary gland of the normal mouse to uncover new effectors that operate immediately downstream of the progesterone mammary signal. Examination of the resultant progesterone-responsive transcriptome disclosed inhibitor of differentiation or DNA binding 4 (Id4) as a molecular target acutely induced by progesterone in the murine mammary epithelium.
Transcriptional response of the murine mammary gland to acute progesterone exposure.
No sample metadata fields
View SamplesCCAAT/enhancer binding protein beta (C/EBPb) is a member of a family of highly conserved transcription factors that regulates numerous genes involved in proliferation and differentiation in a variety of tissues. C/EBPb is deregulated in human breast cancer and germline deletion of this gene results in multiple defects in mammary gland development. We hypothesized that C/EBPb regulates mammary stem cell self-renewal, maintenance and/or differentiation through the regulation of multiple target genes that coordinate mammary gland development. Utilizing both a germline knockout mouse model and a conditional knockout strategy, we demonstrated that mammosphere formation was significantly decreased in C/EBPb-deficient mammary epithelial cells (MECs). The ability of C/EBPb-deleted MECs to regenerate the mammary gland in vivo was severely impaired when transplanted at limiting dilution. Furthermore, serial transplantation of C/EBPb-null mammary tissue resulted in decreased outgrowth potential when compared to wildtype, and an early senescence phenotype. Flow cytometric analysis revealed that C/EBPb-null MECs contain a lower frequency of repopulating stem cells accompanied by an increase in committed, differentiated luminal cells as compared to wildtype. Microarray analysis of stem/progenitor cell populations was performed and revealed an alteration in cell fate specification in C/EBPb-null glands, exemplified by the aberrant expression of basal markers in the luminal cell compartment. Collectively, our studies demonstrate that C/EBPb is a critical regulator of mammary stem cell differentiation, and an important determinant of luminal cell fate specification.
CCAAT/enhancer binding protein beta regulates stem cell activity and specifies luminal cell fate in the mammary gland.
Specimen part
View SamplesSRC-2 is frequently amplified or overexpressed in metastatic prostate cancer patients. In this study, we used genetically engineered mice, overexpressing SRC-2 specifically in the prostate epithelium as a mouse model to examine the role of SRC-2 in prostate tumorigenesis. Over-expression of SRC-2 in PTEN heterozygous mice accelerates PTEN mutation induced tumor progression and develops a metastasis-prone cancer.
Androgen deprivation-induced NCoA2 promotes metastatic and castration-resistant prostate cancer.
Age, Specimen part
View SamplesTo elucidate the mechanisms by which the mir-200 and the miR-183~96~182 cluster could regulate EMT and thus cellular migration, invasion and metastasis in NSCLC, we searched for common predicted targets of these microRNA families that might have a potential role in these biological processes. First we performed a cross comparison of multiple gene expression datasets from our mouse models of metastasis. We overlapped 224 genes that were elevated greater than four-folds upon Zeb1 induction in 393P cells with 210 genes that showed greater than two-fold increase in expression in the metastatic 344SQ cells compared to the non-metastatic 393P cells and 143 genes that were repressed to less than 0.5-fold in cells with exogenous expression of miR-200. This resulted in an enriched list of 45 genes that are potential miR-200 targets having a role in the process of EMT and metastasis. Next we performed an overlap of genes that were predicted targets of the miR-200 family members and the miR-183~96~182 cluster using the microRNA prediction algorithms miRanda (www.microRNA.org) and identified a list of 17 highly conserved common targets with a mirSVR score less than -6.0. The only 2 genes common in both the overlapping subsets were Zeb1 and Foxf2.
The miR-200 family and the miR-183~96~182 cluster target Foxf2 to inhibit invasion and metastasis in lung cancers.
Cell line, Treatment
View SamplesMetastatic disease is a primary cause of cancer-related death, and factors governing tumor cell metastasis have not been fully elucidated. Here we addressed this question by using tumor cell lines derived from mice that develop metastatic lung adenocarcinoma owing to expression of mutant K-ras and p53. A feature of metastasis-prone tumor cells that distinguished them from metastasis-incompetent tumor cells was plasticity in response to changes in their microenvironment. They transited reversibly between epithelial and mesenchymal states, forming highly polarized epithelial spheres in 3-dimensional culture that underwent epithelial-mesenchymal transition (EMT) following treatment with transforming growth factor-beta or injection into syngeneic mice. This plasticity was entirely dependent upon the microRNA-200 family, which decreased during EMT. Forced expression of miR-200 abrogated the capacity of these tumor cells to undergo EMT, invade, and metastasize and conferred transcriptional features of metastasis-incompetent tumor cells. We conclude that microenvironmental cues direct tumor metastasis by regulating miR-200 expression.
Contextual extracellular cues promote tumor cell EMT and metastasis by regulating miR-200 family expression.
Cell line
View SamplesIn order to gain a better understanding of Ihh action during embryo implantation, we constitutively activated Smo in the murine uterus using the PRcre mouse model (PRcre/+SmoM2+; SmoM2). Female SmoM2 mice were infertile. They exhibited normal serum progesterone levels and normal ovulation, but ova failed to be fertilized in vivo and the uterus failed to undergo the artificially induced decidual response. SmoM2 mice exhibited uterine hypertrophy. The endometrium had a reduced number of uterine glands and the endometrial stroma lost its normal morphologic characteristics. Microarray analysis of 3 month old SmoM2 uteri demonstrated a chondrocytic signature and confirmed that constitutive activation of SmoM2 increased extracellular matrix production. Thus, constitutive activation of Smo in the mouse uterus alters the extracellular matrix which interferes with early pregnancy.
Constitutive activation of smoothened leads to female infertility and altered uterine differentiation in the mouse.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Expression signatures of metastatic capacity in a genetic mouse model of lung adenocarcinoma.
No sample metadata fields
View SamplesTumor cells that give rise to metastatic disease are a primary cause of cancer-related death and have not been fully elucidated in patients with lung cancer. Here, we addressed this question by using tissues from a mouse that develops metastatic lung adenocarcinoma owing to expression of mutant K-ras and p53. We identified a metastasis-prone population of tumor cells that differed from those with low metastatic capacity on the basis of having sphere-forming capacity in Matrigel cultures, increased expression of CD133 and Notch ligands, and relatively low tumorigenicity in syngeneic mice. Knockdown of jagged1 or pharmacologic inhibition of its downstream mediator phosphatidylinositol 3-kinase abrogated the metastatic but not the tumorigenic activity of these cells. We conclude from these studies on a mouse model of lung adenocarcinoma that CD133 and Notch ligands mark a population of metastasis-prone tumor cells and that the efficacy of Notch inhibitors in metastasis prevention should be explored.
The Notch ligand Jagged2 promotes lung adenocarcinoma metastasis through a miR-200-dependent pathway in mice.
Specimen part
View SamplesLung cancer remains the leading cause of cancer death. Genome sequencing of lung tumors from patients with Squamous Cell Carcinoma has identified SMAD4 to be frequently mutated. Here we used a novel mouse model to determine the molecular mechanisms regulated by loss of Smad4 which lead to lung cancer progression. Mice with ablation of Pten and Smad4 in airway epithelium developed metastatic adenosquamous tumors. Comparative transcriptomic and in vivo cistromic analyses determined that loss of PTEN and SMAD4 resulted in activation of the ELF3 and the ErbB2 pathway due to decreased ERRFI1s expression, a negative regulator of ERBB2 in mice and human cells. The combinatorial inhibition of ErbB2 and Akt signaling attenuated tumor progression and cell invasion, respectively. Expression profiles analysis of human lung tumors substantiated the importance of the ErbB2/Akt/ELF3 signaling pathway as both prognostic biomarkers and therapeutic drug targets for treating lung cancer.
ErbB2 Pathway Activation upon Smad4 Loss Promotes Lung Tumor Growth and Metastasis.
Age, Specimen part
View Samples