Cyclooxygenase-2 (COX-2) is upregulated in pancreatic ductal adenocarcinomas (PDAC). However, how COX-2 promotes PDAC development is unclear. While previous studies have evaluated the efficacy of COX-2 inhibition via the use of non steroidal anti-inflammatory drugs (NSAIDs) or the COX-2 inhibitor celecoxib in PDAC models, none have addressed the cell intrinsic vs. microenvironment roles of COX-2 in modulating PDAC initiation and progression. We tested the cell intrinsic role of COX-2 in PDAC progression, using both loss-of-function and gain-of-function approaches. Cox-2 deletion in Pdx1+ pancreatic progenitor cells significantly delays the development of PDAC in mice with K-ras activation and Pten haploinsufficiency. Conversely, COX-2 over-expression promotes early onset and progression of PDAC in the K-ras mouse model. Loss of PTEN function is a critical factor in determining lethal PDAC onset and overall survival. Mechanistically, COX-2 over-expression increases P-AKT levels in the precursor lesions of Pdx1+;K-rasG12D/+;Ptenlox/+ mice in the absence of Pten LOH. In contrast, Cox-2 deletion in the same setting diminishes P-AKT levels and delays cancer progression. These data suggest an important cell intrinsic role for COX-2 in tumor initiation and progression through activation of the PI3K/AKT pathway. PDAC that is independent of intrinsic COX-2 expression eventually develops with decreased FKBP5 and increased GRP78 expression, two alternate pathways leading to AKT activation. Together, these results support a cell intrinsic role for COX-2 in PDAC development and suggest that, while anti-COX-2 therapy may delay the development and progression of PDAC, mechanisms known to increase chemoresistance through AKT activation must also be overcome.
Cell intrinsic role of COX-2 in pancreatic cancer development.
Specimen part
View SamplesBRAF inhibitors are highly effective therapies for patients with BRAF V600 mutated metastatic melanoma. Patients who receive BRAF inhibitors develop a variety of hyper-proliferative skin conditions, whose pathogenic basis is the paradoxical activation of the mitogen-activated protein kinase (MAPK) pathway in BRAF wild-type cells. Most of these hyper-proliferative skin changes improve when a MEK inhibitor is co-administered, as a MEK inhibitor blocks paradoxical MAPK activation. We tested whether we could take advantage of the mechanistic understanding of the skin hyper-proliferative side effects of BRAF inhibitors to accelerate skin wound healing by inducing paradoxical MAPK activation. Here we show that the BRAF inhibitor vemurafenib accelerates human keratinocyte proliferation and migration by increasing ERK phosphorylation and cell cycle progression. Topical treatment with vemurafenib in two wound-healing models in mice accelerated cutaneous wound healing and improved the tensile strength of healing wounds through paradoxical MAPK activation; addition of a MEK inhibitor reversed the benefit of vemurafenib-accelerated wound healing. The same dosing regimen of topical BRAF inhibitor did not increase the incidence of cutaneous squamous cell carcinomas in mice even after the application of a carcinogen. Therefore, topical BRAF inhibitors may have clinical applications in accelerating the healing of skin wounds. Overall design: Full depth incisional wound mice tissues with/without Vemurafenib treatment were sent for RNAseq analysis on day 2, 6 and 14
Cutaneous wound healing through paradoxical MAPK activation by BRAF inhibitors.
Specimen part, Subject
View SamplesPreeclampsia complicates more than 3% of all pregnancies in the United States and Europe. High-risk populations include women with diabetes, dyslipidemia, thrombotic disorders, hyperhomocysteinemia, hypertension, renal diseases, previous preeclampsia, twin pregnancies, and low socioeconomic status. In the latter case, the incidence may increase to 20% to 25%. Preeclampsia is a major cause of maternal and fetal morbidity and mortality. Preeclampsia is defined by systolic blood pressure of more than 140 mm Hg and diastolic blood pressure of more than 90 mm Hg after 20 weeks gestation in a previously normotensive patient, and new-onset proteinuria. Abnormal placentation associated with shallow trophoblast invasion (fetal cells from outer cell layer of the blastocyst) into endometrium (decidua) and improper spiral artery remodeling in the decidua are initial pathological steps.
Dysregulation of the circulating and tissue-based renin-angiotensin system in preeclampsia.
No sample metadata fields
View SamplesTo accelerate the development of disease-modifying therapeutics for Huntingtons disease (HD), a dynamic biomarker of disease activity and treatment response is critically needed.
Transcriptional modulator H2A histone family, member Y (H2AFY) marks Huntington disease activity in man and mouse.
Sex, Specimen part
View SamplesWe report a mouse model that recapitulates expression of the ETV6-NTRK3 (EN) fusion oncoprotein, the product of the t(12;15)(p13;q25) translocation characteristic of human secretory breast carcinoma. Activation of EN expression in mammary tissues by Whey acidic protein (Wap) promoter-driven Cre leads to fully penetrant, multifocal malignant breast cancer with short latency. We provide genetic evidence that committed bipotent or CD61+ luminal alveolar progenitors, are targets of tumorigenesis. Furthermore, EN transforms these otherwise transient progenitors through activation of the AP1 complex. Given increasing relevance of chromosomal translocations in epithelial cancers, such mice serve as a paradigm for the study of their genetic pathogenesis and cellular origins, and generation of novel preclinical models.
ETV6-NTRK3 fusion oncogene initiates breast cancer from committed mammary progenitors via activation of AP1 complex.
No sample metadata fields
View SamplesWe report a mouse model that recapitulates expression of the ETV6-NTRK3 (EN) fusion oncoprotein, the product of the t(12;15)(p13;q25) translocation characteristic of human secretory breast carcinoma. Activation of EN expression in mammary tissues by Whey acidic protein (Wap) promoter-driven Cre leads to fully penetrant, multifocal malignant breast cancer with short latency. We provide genetic evidence that committed bipotent or CD61+ luminal alveolar progenitors, are targets of tumorigenesis. Furthermore, EN transforms these otherwise transient progenitors through activation of the AP1 complex.
ETV6-NTRK3 fusion oncogene initiates breast cancer from committed mammary progenitors via activation of AP1 complex.
No sample metadata fields
View SamplesTumor growth and metastasis is controlled by paracrine signaling between cells of the tumor microenvironment and malignant cells. Cancer-associated fibroblasts (CAFs), are functionally important components of the tumor microenvironment. Although some steps involved in the cross-talk between these cells are known, there is still a lot that is not clear. Thus, the addition of, the consideration of microenvironment in the development of the disease, to the clinical and pathological procedures (currently admitted as the consistent value cancer treatments) could lay the foundations for the development of new treatment strategies to control the disease.
Functional heterogeneity of cancer-associated fibroblasts from human colon tumors shows specific prognostic gene expression signature.
Specimen part
View SamplesWe report a mouse model that recapitulates expression of the ETV6-NTRK3 (EN) fusion oncoprotein, the product of the t(12;15)(p13;q25) translocation characteristic of human secretory breast carcinoma. Activation of EN expression in mammary tissues by Whey acidic protein (Wap) promoter-driven Cre leads to fully penetrant, multifocal malignant breast cancer with short latency. We provide genetic evidence that committed bipotent or CD61+ luminal alveolar progenitors, are targets of tumorigenesis. Furthermore, EN transforms these otherwise transient progenitors through activation of the AP1 complex. Given increasing relevance of chromosomal translocations in epithelial cancers, such mice serve as a paradigm for the study of their genetic pathogenesis and cellular origins, and generation of novel preclinical models.
ETV6-NTRK3 fusion oncogene initiates breast cancer from committed mammary progenitors via activation of AP1 complex.
No sample metadata fields
View SamplesSurface topography impacts on cell growth and differentiation, but it is not trivial to generate homogeneous surface structures and to define the specific morphological parameters of relevance. In this study, we have compared gene expression profiles of mesenchymal stem cells (MSCs) on nanostructured groove/ridge surfaces. Patterns were generated in polyimide using multi beam laser interference. These structures affected cell size and orientation of human MSCs. Furthermore, the nano-patterns with a periodicity of 650 nm increased differentiation towards osteogenic and adipogenic lineages. However, in absence of differentiation media the surface structures did neither induce differentiation, nor lineage-specific gene expression changes as assessed by genome wide gene expression profiles with Affymetrix microarray technology. Our results demonstrate that grooves and ridges at a periodicity of 650 nm enhance the propensity of MSCs to differentiate towards adipogenic and/or osteogenic lineages but they do not directly govern lineage-specific gene expression changes.
Surface topography enhances differentiation of mesenchymal stem cells towards osteogenic and adipogenic lineages.
Specimen part, Subject
View SamplesTranscriptional dysregulation plays a major role in the pathology of Huntington's disease (HD). However, the mechanisms causing selective downregulation of genes remain unknown. Histones regulate chromatin structure and thereby control gene expression; recent studies have demonstrated a therapeutic role for histone deacetylase (HDAC) inhibitors in polyglutamine diseases. This study demonstrates that despite no change in overall acetylated histone levels, histone H3 is hypo-acetylated at promoters of downregulated genes in R6/2 mice, ST14a and STHdh cells, as demonstrated by in vivo chromatin immunoprecipitation. In addition, HDAC inhibitor treatment increases association of acetylated histones with downregulated genes and corrects mRNA abnormalities. In contrast, there is a decrease in mRNA levels in wild-type cells following treatment with a histone acetyltransferase inhibitor. Although changes in histone acetylation correlate with decreased gene expression, histone hypo-acetylation may be a late event, as no hypo-acetylation is observed in 4-week-old R6/2 mice. Nevertheless, treatment with HDAC inhibitors corrects mRNA abnormalities through modification of histone proteins and may prove to be of therapeutic value in HD.
Histones associated with downregulated genes are hypo-acetylated in Huntington's disease models.
No sample metadata fields
View Samples