PRONGF/NGF and nerve infiltration in prostate and breast cancer

Research Doctorate - Doctor of Philosophy (PhD)Nerve fibre infiltration has recently been demonstrated as paramount to the tumor microenvironment and essential to cancer progression. However, it has not been clearly elucidated what attracts neuronal fibres into tumors. A plausible explanation is the overexpression of neurotrophic factors, such as nerve growth factor (NGF) or its precursor proNGF. These proteins are distinctively involved in neuronal survival/apoptosis through interactions with specific membrane receptors such as TrkA, p75^NTR and sortilin. This thesis aims to show whether proNGF/NGF overexpression drives nerve infiltration in prostate and breast cancer. What has been showed herein is that the overexpression of proNGF in a cohort of 104 prostate cancer cases, observed using immunohistochemistry has a direct correlation with the aggressiveness of prostate cancer (t_B= 0.51). A 60-kilodalton proNGF was detected by western blotting of prostate cancer cells, whereas the proteolytically processed NGF was not detected. In addition, we performed an in vitro co-culture of prostate cancer cells with neuronal cells and demonstrated the neurotrophic effect of prostate cancer cells to stimulate axonogenesis via the secretion of proNGF. Furthermore, in breast cancer we have shown nerve fibre infiltration by immunohistochemistry using the neuronal marker protein gene product (PGP) 9.5. Nerve infiltration was found to be associated with NGF expression and lymph node invasion. Secreted NGF was detected by dot blot analysis of conditioned medium from breast cancer cells. Interestingly, in vitro co-culture assays demonstrated that NGF secreted from breast cancer cells stimulated neurite outgrowth of neuronal cells, and that this effect could be inhibited by using an anti-NGF blocking antibody, thus supporting the neurotrophic potential of these cells. In conclusion, we have shown that proNGF is a driver of nerve infiltration in prostate cancer and that a similar phenomenon occurs in breast cancer via NGF. This study suggests new avenues for inhibiting prostate and breast cancer growth and metastasis by inhibiting axonogenesis via the targeting of proNGF and NGF

Bathymetry and hydrobiology of Lake Mahagnao, Leyte

Lake Mahagnao in Burauen, Leyte (10° 52.15' N and 124° 51.32' E) lies 26 m above sea level. It is surrounded by a mountain range that includes a dormant twin volcano. A bathymetric survey established 122 sampling stations using Global Positioning System. The stations formed transect lines across the lake. A bathymetric map of Lake Mahagnao was generated with the use of the SURFER software. Lake Mahagnao has a shoreline of 15,590 m and surface area of 15.75 ha. The deepest portion of the lake is 18.75 m. The mean pH of the water is 6.58; water surface temperature, 27oC; and water visibility, 1.64 m. Eighty-one species were identified as primary producers. Station 5, the deepest portion of the lake, had the highest phytoplankton density at 4,716 cells/ml and Station 2 had only 634 cells/ml. Cyanobacteria were the most abundant in all the sampling stations

NGF and ProNGF: Regulation of neuronal and neoplastic responses through receptor signaling.

Nerve growth factor (NGF) and its precursor (proNGF) are primarily considered as regulators of neuronal function that induce their responses via the tyrosine kinase receptor TrkA and the pan-neurotrophin receptor p75NTR. It has been generally held that NGF exerts its effects primarily through TrkA, inducing a cascade of tyrosine kinase-initiated responses, while proNGF binds more strongly to p75NTR. When this latter entity interacts with a third receptor, sortilin, apoptotic responses are induced in contrast to the survival/differentiation associated with the other two. Recent studies have outlined portions of the downstream phosphoproteome of TrkA in the neuronal PC12 cells and have clarified the contribution of individual docking sites in the TrkA endodomain. The patterns observed showed a similarity with the profile induced by the epidermal growth factor receptor, which is extensively associated with oncogenesis. Indeed, as with other neurotrophic factors, the distribution of TrkA and p75NTR is not limited to neuronal tissue, thus providing an array of targets outside the nervous systems. One such source is breast cancer cells, in which NGF and proNGF stimulate breast cancer cell survival/growth and enhance cell invasion, respectively. This latter activity is exerted via TrkA (as opposed to p75NTR) in conjunction with sortilin. Another tissue overexpressing proNGF is prostate cancer and here the ability of cancer cells to induce neuritogenesis has been implicated in cancer progression. These studies show that the non-neuronal functions of proNGF/NGF are likely integrated with their neuronal activities and point to the clinical utility of these growth factors and their receptors as biomarkers and therapeutic targets for metastasis and cancer pain

Ignition and combustion characteristics of various biodiesel fuels (BDFs)

Abstract The fundamental data of ignition and combustion characteristics of various biodiesel fuels (BDFs) are exhibited for finding the optimal condition in diesel engines. The experimental research has been conducted in a constant-volume vessel with the pre-burn system under diesel-engine conditions. The ignition delays and heat release rates were investigated under different ambient temperatures and pressures. This study used diesel oil and various BDFs such as jatropha methyl ester (JME), coconut methyl ester (CME), soybean methyl ester (SME) and palm methyl ester (PME). The experimental results on fuel-spray development and combustion characteristics were affected by the properties of biodiesel fuels (BDFs), which may support potentially the optimal design of diesel engine fueled with BDFs. Evaporation and mixing are promoted at the tip of fuel jet with lower distillation temperature and lower viscosity, resulting in a shorter length dense region in the spray. These properties may disturb the mixture formation of BDFs at spray tip although the penetration lengths are almost same. The ambient temperature (Ti) and ambient pressure (pi) strongly influenced the ignition and combustion processes of BDF and diesel oil. Though ignition delays of all BDFs are shorter than that of diesel oil in the whole temperature range from 600 K to 1200 K, CME exhibits the significant shortest delay, suggesting a dominant effect of physical properties of mixing process. At the ambient temperature 800 K and 4 MPa, all of BDFs and diesel oil predict the similar histories of heat release rate. The pre-mixture combustion with longer ignition delay dominates the combustion process at 700 K, but its period is almost constant irrespective of BDF. Ignition delay becomes longer than the injection period for high density and viscosity tested fuels, resulting in a very slow combustion. © 2015 Elsevier Ltd

Cxcr3-expressing leukocytes are necessary for neurofibroma formation in mice.

Plexiform neurofibroma is a major contributor to morbidity in patients with neurofibromatosis type I (NF1). Macrophages and mast cells infiltrate neurofibroma, and data from mouse models implicate these leukocytes in neurofibroma development. Antiinflammatory therapy targeting these cell populations has been suggested as a means to prevent neurofibroma development. Here, we compare gene expression in Nf1-mutant nerves, which invariably form neurofibroma, and show disruption of neuron-glial cell interactions and immune cell infiltration to mouse models, which rarely progresses to neurofibroma with or without disruption of neuron-glial cell interactions. We find that the chemokine Cxcl10 is uniquely upregulated in NF1 mice that invariably develop neurofibroma. Global deletion of the CXCL10 receptor Cxcr3 prevented neurofibroma development in these neurofibroma-prone mice, and an anti-Cxcr3 antibody somewhat reduced tumor numbers. Cxcr3 expression localized to T cells and DCs in both inflamed nerves and neurofibromas, and Cxcr3 expression was necessary to sustain elevated macrophage numbers in Nf1-mutant nerves. To our knowledge, these data support a heretofore-unappreciated role for T cells and DCs in neurofibroma initiation

SOD1 protein aggregates stimulate macropinocytosis in neurons to facilitate their propagation

Background Amyotrophic Lateral Sclerosis is characterized by a focal onset of symptoms followed by a progressive spread of pathology that has been likened to transmission of infectious prions. Cell-to-cell transmission of SOD1 protein aggregates is dependent on fluid-phase endocytosis pathways, although the precise molecular mechanisms remain to be elucidated. Results We demonstrate in this paper that SOD1 aggregates interact with the cell surface triggering activation of Rac1 and subsequent membrane ruffling permitting aggregate uptake via stimulated macropinocytosis. In addition, other protein aggregates, including those associated with neurodegenerative diseases (TDP-43, Htt ex1 46Q, α-synuclein) also trigger membrane ruffling to gain entry into the cell. Aggregates are able to rupture unstructured macropinosomes to enter the cytosol allowing propagation of aggregation to proceed. Conclusion Thus, we conclude that in addition to basic proteostasis mechanisms, pathways involved in the activation of macropinocytosis are key determinants in the spread of pathology in these misfolding diseases