Publications by authors named "Whitaker-Menezes D"

Mesenchymal-epithelial plasticity driving cancer progression in cancer-associated fibroblasts (CAFs) is undetermined. This work identifies a subgroup of CAFs in human breast cancer exhibiting mesenchymal-to-epithelial transition (MET) or epithelial-like profile with high miR-200c expression. MiR-200c overexpression in fibroblasts is sufficient to drive breast cancer aggressiveness.

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Breast cancer is composed of metabolically coupled cellular compartments with upregulation of TP53 Induced Glycolysis and Apoptosis Regulator (TIGAR) in carcinoma cells and loss of caveolin 1 (CAV1) with upregulation of monocarboxylate transporter 4 (MCT4) in fibroblasts. The mechanisms that drive metabolic coupling are poorly characterized. The effects of TIGAR on fibroblast CAV1 and MCT4 expression and breast cancer aggressiveness was studied using coculture and conditioned media systems and in-vivo.

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Alterations in muscle structure and function in chronic kidney disease (CKD) patients are associated with poor outcomes. As key organelles in muscle cell homeostasis, mitochondrial metabolism has been studied in the context of muscle dysfunction in CKD. We conducted a study to determine the contribution of oxidative metabolism, glycolysis and fatty acid oxidation to the muscle metabolism in CKD.

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The most common cancers of the aerodigestive tract (ADT) are non-small cell lung cancer (NSCLC) and head and neck squamous cell carcinoma (HNSCC). The tumor stroma plays an important role in ADT cancer development and progression, and contributes to the metabolic heterogeneity of tumors. Cancer-associated fibroblasts (CAFs) are the most abundant cell type in the tumor stroma of ADT cancers and exert pro-tumorigenic functions.

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Post-transplant lymphoproliferative disorders (PTLD) are among the most serious complications after solid organ transplantation (SOT). Monomorphic diffuse large B-cell lymphoma (DLBCL) is the most common subtype of PTLD. Historically, outcomes of PTLD have been poor with high mortality rates and allograft loss, although this has improved in the last 10 years.

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Oral squamous cell carcinoma (OSCC) is the most common subsite of head and neck cancer, with a 5-year survival rate of only 50%. There is a pressing need for animal models that recapitulate the human disease to understand the factors driving OSCC carcinogenesis. Many laboratories have used the chemical carcinogen 4-nitroquinoline-1-oxide (4NQO) to investigate OSCC formation.

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In obesity, adipose tissue derived inflammation is associated with unfavorable metabolic consequences. Uremic inflammation is prevalent and contributes to detrimental outcomes. However, the contribution of adipose tissue inflammation in uremia has not been characterized.

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Chondrosarcoma is the second most common primary bone malignancy, representing one fourth of all primary bone sarcomas. It is typically resistant to radiation and chemotherapy treatments. However, the molecular mechanisms that contribute to cancer aggressiveness in chondrosarcomas remain poorly characterized.

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Head and neck squamous cell carcinoma (HNSCC) is comprised of metabolically linked distinct compartments. Cancer-associated fibroblasts (CAF) and nonproliferative carcinoma cells display a glycolytic metabolism, while proliferative carcinoma cells rely on mitochondrial oxidative metabolism fueled by the catabolites provided by the adjacent CAFs. Metabolic coupling between these reprogrammed compartments contributes to HNSCC aggressiveness.

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Metformin, an oral anti-hyperglycemic drug which inhibits mitochondrial complex I and oxidative phosphorylation has been reported to correlate with improved outcomes in head and neck squamous cell carcinoma (HNSCC) and other cancers. This effect is postulated to occur through disruption of tumor-driven metabolic and immune dysregulation in the tumor microenvironment (TME). We report new findings on the impact of metformin on the tumor and immune elements of the TME from a clinical trial of metformin in HNSCC.

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Head and neck squamous cell carcinoma (HNSCC) is the 6th most common human cancer and affects approximately 50,000 new patients every year in the US. The major risk factors for HNSCC are tobacco and alcohol consumption as well as oncogenic HPV infections. Despite advances in therapy, the overall survival rate for all-comers is only 50%.

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Background: High oxidative stress as defined by hydroxyl and peroxyl activity is often found in the stroma of human breast cancers. Oxidative stress induces stromal catabolism, which promotes cancer aggressiveness. Stromal cells exposed to oxidative stress release catabolites such as lactate, which are up-taken by cancer cells to support mitochondrial oxidative phosphorylation.

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Background: Twenty percent of patients with classical Hodgkin Lymphoma (cHL) have aggressive disease defined as relapsed or refractory disease to initial therapy. At present we cannot identify these patients pre-treatment. The microenvironment is very important in cHL because non-cancer cells constitute the majority of the cells in these tumors.

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Metabolic heterogeneity between neoplastic cells and surrounding stroma has been described in several epithelial malignancies; however, the metabolic phenotypes of neoplastic lymphocytes and neighboring stroma in diffuse large B-cell lymphoma (DLBCL) is unknown. We investigated the metabolic phenotypes of human DLBCL tumors by using immunohistochemical markers of glycolytic and mitochondrial oxidative phosphorylation (OXPHOS) metabolism. The lactate importer MCT4 is a marker of glycolysis, whereas the lactate importer MCT1 and TOMM20 are markers of OXPHOS metabolism.

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Objective Many aggressive head and neck cancers contain 2 metabolically coupled tumor compartments: a glycolytic stromal compartment with low caveolin-1 (CAV1) and high monocarboxylate transporter 4 (MCT4) expression and a highly proliferative carcinoma cell compartment with high MCT1. Metabolites are shuttled by MCTs from stroma to carcinoma to fuel tumor growth. We studied the effect of carcinoma-fibroblast coinjection and metformin administration on a mouse model of head and neck squamous cell carcinoma.

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Objective In many cancers, including head and neck squamous cell carcinoma (HNSCC), different regions within a tumor have different metabolic phenotypes. Transfer of metabolites between compartments promotes tumor growth and aggressive behavior. Metabolic compartmentalization in HNSCC nodal metastases has not been studied, nor has its impact on extracapsular extension or clinical outcomes been determined.

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Background.: End-stage renal disease (ESRD) is associated with inflammation and increased reactive oxygen species (ROS). Inflammation and oxidative stress are associated with several complications of ESRD.

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Monocarboxylate transporter 1 (MCT1) is an importer of monocarboxylates such as lactate and pyruvate and a marker of mitochondrial metabolism. MCT1 is highly expressed in a subgroup of cancer cells to allow for catabolite uptake from the tumor microenvironment to support mitochondrial metabolism. We studied the protein expression of MCT1 in a broad group of breast invasive ductal carcinoma specimens to determine its association with breast cancer subtypes and outcomes.

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A subgroup of breast cancers has several metabolic compartments. The mechanisms by which metabolic compartmentalization develop in tumors are poorly characterized. TP53 inducible glycolysis and apoptosis regulator (TIGAR) is a bisphosphatase that reduces glycolysis and is highly expressed in carcinoma cells in the majority of human breast cancers.

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Here, we interrogated head and neck cancer (HNSCC) specimens (n = 12) to examine if different metabolic compartments (oxidative vs. glycolytic) co-exist in human tumors. A large panel of well-established biomarkers was employed to determine the metabolic state of proliferative cancer cells.

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The role of PPARγ in cancer therapy is controversial, with studies showing either pro-tumorigenic or antineoplastic effects. This debate is very clinically relevant, because PPARγ agonists are used as antidiabetic drugs. Here, we evaluated if the effects of PPARγ on tumorigenesis are determined by the cell type in which PPARγ is activated.

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Cigarette smoke has been directly implicated in the disease pathogenesis of a plethora of different human cancer subtypes, including breast cancers. The prevailing view is that cigarette smoke acts as a mutagen and DNA damaging agent in normal epithelial cells, driving tumor initiation. However, its potential negative metabolic effects on the normal stromal microenvironment have been largely ignored.

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Here, we provide the necessary proof of concept, that it is possible to metabolically create a non-permissive or "hostile" stromal microenvironment, which actively prevents tumor engraftment in vivo. We developed a novel genetically engineered fibroblast cell line that completely prevents tumor formation in mice, with a 100% protection rate. No host side effects were apparent.

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Mutations in the BRCA1 tumor suppressor gene are commonly found in hereditary breast cancer. Similarly, downregulation of BRCA1 protein expression is observed in the majority of basal-like breast cancers. Here, we set out to study the effects of BRCA1 mutations on oxidative stress in the tumor microenvironment.

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