Project description:The energy metabolism of tumors is biased toward glycolysis called as the Warburg effect. The tumor microenvironment is known to be hypoxic, which leads to activating hypoxia-inducible factor 1α (HIF1α) in tumor cells. The high expression of HIF1α plays a functional role in the enhancement of glycolysis and is correlated to poor outcomes in human cancers. However, in dogs, the molecular mechanisms involved in hypoxic tumor cells remain to be elucidated. In the present study, we investigated upregulated genes in hypoxia by RNA-seq analysis, the expression of proteins related to glycolysis in hypoxia by western blotting (WB), and the expression of the monocarboxylate transporter4 (MCT4) in a total of 96 canine tumor tissue by immunohistochemical (IHC) staining. The glycolysis and HIF-1 signaling pathways were upregulated in hypoxic melanoma cells by RNA-seq and WB. In addition, the experiment using HIF1α knockout melanoma cells showed a marker of glycolysis MCT4 was regulated by HIF1α activation. Hypoxia induced high lactate secretion due to the enhancement of glycolysis in canine melanoma cells. IHC analysis revealed membrane-localization of MCT4 protein was observed in urothelial carcinoma and lung adenocarcinoma tissues. We concluded canine MCT4 protein has a role in lactic acid efflux from glycolytic cells and might be a novel marker of hypoxia and glycolysis in canine tumors. This data may also be important in finding a new therapeutic target for MCT4 in the future.
Project description:To investigate the role of hypoxia treatment on the metabolic profiles of canine glioma cells We then performed reduce representation bisulfite sequencing on 3 unique canine cell lines and correlated with functional assays
Project description:The recently developed COXEN method (PMID: 17666531) has been used to successfully extrapolate gene signatures of drug sensitivity across different tumor histotypes. We wanted to explore the utility of COXEN to predict chemosensitivity in canine cancer, specifically if we could extrapolate gene signatures identified in human datasets over to canine osteosarcoma tumors. This dataset of canine osteosarcoma tumor samples has available clinical outcome data after patients had infected limbs amputated and were treated with doxorubicin and/or carboplatin. We performed microarray analysis on this panel of tumor samples for validating our COXEN prediction models for doxorubicin or carboplatin sensitivity.
Project description:<p>The identification of efficient and sensitive biomarkers for non-invasive tests is one of the major challenges in cancer diagnosis. To address this challenge, metabolomics is widely applied for identifying biomarkers that detects abnormal changes in cancer patients. Canine mammary tumors exhibit physiological characteristics identical to those in human breast cancer and serve as a useful animal model to conduct breast cancer research. Here, we aimed to provide a reliable large-scale metabolite dataset collected from dogs with mammary tumors, using proton nuclear magnetic resonance spectroscopy. We identified 55 metabolites in urine samples from 20 benign, 87 malignant, and 49 healthy control subjects. This dataset provides details of mammary tumor-specific metabolites in dogs and insights into cancer-specific metabolic alterations that share similar molecular characteristics.</p>
Project description:The recently developed COXEN method (PMID: 17666531) has been used to successfully extrapolate gene signatures of drug sensitivity across different tumor histotypes. We wanted to explore the utility of COXEN to predict chemosensitivity in canine cancer, specifically if we could extrapolate gene signatures identified in human datasets over to canine osteosarcoma tumors. This dataset of canine osteosarcoma tumor samples has available clinical outcome data after patients had infected limbs amputated and were treated with doxorubicin and/or carboplatin. We performed microarray analysis on this panel of tumor samples for validating our COXEN prediction models for doxorubicin or carboplatin sensitivity. Chemotherapy naive primary tumors were collected at the time of amputation and archived at the Flint Animal Cancer Center. RNA was extracted from 33 frozen archived tumor samples, followed by microarray analysis. The gene expression data was RMA preprocessed, scaled and were used as a independent test set to evaluate developed prediction models of sensitivity to doxorubicin or carboplatin. Drug predictions were than compared to clinical outcome in these patients that received doxorubicin and/or carboplatin.
Project description:The anatomic location and immunologic characteristics of brain tumors result in strong lymphocyte suppression. Consequently, conventional immunotherapies targeting CD8 T-cells are ineffective against brain tumors. Tumor cells escape immunosurveillance by various mechanisms, and tumor cell metabolism can affect the metabolic states and functions of tumor-infiltrating lymphocytes. Oxygen tension is one important factor influencing immune responses. Here, we discovered that brain tumor cells had a particularly high demand for oxygen, which affected γδ T-cell-mediated antitumor immune responses but not those of conventional T-cells. Specifically, tumor hypoxia activated the γδ T-cell protein kinase A (PKA) pathway at a transcriptional level, resulting in repression of NKG2D expression. Alleviating tumor hypoxia reinvigorated NKG2D expression and the antitumor function of γδ T-cells. These results reveal a hypoxia-mediated mechanism by which brain tumors and γδ T-cells interact and emphasize the importance of γδ T-cells for antitumor immunity against brain tumors.