Rabbit Anti-Human PRKCD Polyclonal Antibody

Background: Osteosarcoma (OSA) is lethal when metastatic after chemotherapy and/or surgical treatment. Thus animal models are necessary to study the OSA metastatic spread and to validate novel therapies able to control the systemic disease. We report the development of a syngeneic (Balb/c) murine OSA model, using a cell line derived from a spontaneous murine tumor. Methodology: The tumorigenic and metastatic ability of OSA cell lines were assayed after orthotopic injection in mice distal femur. Expression profiling was carried out to characterize the parental and metastatic cell lines. Cells from metastases were propagated and engineered to express Luciferase, in order to follow metastases in vivo. Principal Findings: Luciferase bioluminescence allowed to monitor the primary tumor growth and revealed the appearance of spontaneous pulmonary metastases. In vivo assays showed that metastasis is a stable property of metastatic OSA cell lines after both propagation in culture and luciferase trasduction. When compared to parental cell line, both unmodified and genetically marked metastatic cells, showed comparable and stable differential expression of the enpp4, pfn2 and prkcd genes, already associated to the metastatic phenotype in human cancer. Conclusions: This OSA animal model faithfully recapitulates some of the most important features of the human malignancy, such as lung metastatization. Moreover, the non-invasive imaging allows monitoring the tumor progression in living mice. A great asset of this model is the metastatic phenotype, which is a stable property, not modifiable after genetic manipulation.

Decreased collateral vessel formation in diabetic peripheral limbs is characterized by abnormalities of the angiogenic response to ischemia. Hyperglycemia is known to activate protein kinase C (PKC), affecting the expression and activity of growth factors such as vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF). The current study investigates the role of PKC delta in diabetes-induced poor collateral vessel formation and inhibition of angiogenic factors expression and actions. Ischemic adductor muscles of diabetic Prkcd(+/+) mice exhibited reduced blood reperfusion, vascular density, and number of small vessels compared with nondiabetic Prkcd(+/+) mice. By contrast, diabetic Prkcd(-/-) mice showed significant increased blood flow, capillary density, and number of capillaries. Although expression of various PKC isoforms was unchanged, activation of PKC delta was increased in diabetic Prkcd(+/+) mice. VEGF and PDGF mRNA and protein expression were decreased in the muscles of diabetic Prkcd(+/+) mice and were normalized in diabetic Prkcd(-/-) mice. Furthermore, phosphorylation of VEGF receptor 2 (VEGFR2) and PDGF receptor-beta (PDGFR-beta) were blunted in diabetic Prkcd(-/-) mice but elevated in diabetic Prkcd(-/-) mice. The inhibition of VEGFR2 and PDGFR-beta activity was associated with increased SHP-1 expression. In conclusion, our data have uncovered the mechanisms by which PKC delta activation induced poor collateral vessel formation, offering potential novel targets to regulate angiogenesis therapeutically in diabetic patients.