The tumor microenvironment is considered to play an important role in tumor formation and progression by providing both negative and positive signals that influence tumor cell growth. We and others have previously shown that brain tumor (glioma) formation in Nf1 genetically engineered mice requires a microenvironment composed of cells heterozygous for a targeted Nf1 mutation. Using NF1 as a model system to understand the contribution of the tumor microenvironment to glioma formation, we show that Nf1+/- brain microglia produce specific factors that promote Nf1-/- astrocyte growth in vitro and in vivo and identify hyaluronidase as one of these factors in both genetically engineered Nf1 mouse and human NF1-associated optic glioma. We further demonstrate that blocking hyaluronidase ameliorates the ability of Nf1+/- microglia to increase Nf1-/- astrocyte proliferation and that hyaluronidase increases Nf1-/- astrocyte proliferation in an MAPK-dependent fashion. Lastly, inhibiting microglia activation in genetically engineered Nf1 mice significantly reduces mouse optic glioma proliferation in vivo. Collectively, these studies identify Nf1+/- microglia as an important stromal cell type that promotes Nf1-/- astrocyte and optic glioma growth relevant to the pathogenesis of NF1-associated brain tumors and suggest that future brain therapies might be directed against paracrine factors produced by cells in the tumor microenvironment.

Astrocytoma (glioma) formation in neurofibromatosis type 1 (NF1) occurs preferentially along the optic pathway during the first decade of life. The molecular basis for this unique pattern of gliomagenesis is unknown. Previous studies in mouse Nf1 optic glioma models suggest that this patterning results from cooperative effects of Nf1 loss in glial cells and the action of factors derived from the surrounding Nf1+/À brain. Because CXCL12 is a stroma-derived growth factor for malignant brain tumors, we tested the hypothesis that CXCL12 functions in concert with Nf1 loss to facilitate NF1-associated glioma growth. Whereas CXCL12 promoted cell death in wild-type astrocytes, it increased Nf1À/À astrocyte survival. This increase in Nf1À/À astrocyte survival in response to CXCL12 was due to sustained suppression of intracellular cyclic AMP (cAMP) levels. Moreover, the ability of CXCL12 to suppress cAMP and increase Nf1À/À astrocyte survival was a consequence of mitogen-activated protein/extracellular signalregulated kinase kinase-dependent inhibition of CXCL12 receptor (CXCR4) desensitization. In support of an instructive role for CXCL12 in facilitating optic glioma growth, we also show that CXCL12 expression along the optic pathway is higher in infant children and young mice and is associated with low levels of cAMP. CXCL12 expression declines in multiple brain regions with increasing age, correlating with the age-dependent decline in glioma growth in children with NF1. Collectively, these studies provide a mechanism for the unique pattern of NF1-associated glioma growth. [Cancer Res 2007;67(18):8588-95]

Neurofibromatosis-1 (

This is the first report of the production of monoclonal antibodies against elk coronavirus. The nucleoprotein gene of elk coronavirus was amplified by PCR and was cloned and expressed in a prokaryotic expression vector. Recombinant nucleocapsid protein was used to immunize mice for the production of hybridomas. Twelve hybridomas that produced monoclonal antibodies against the nucleocapsid protein of elk coronavirus were selected by an indirect fluorescent-antibody test, an enzyme-linked immunosorbent assay, and a Western blot assay. Ten of the monoclonal antibodies were of the immunoglobulin G1 (IgG1) isotype, one was IgG2a, and one was IgM. All had kappa light chains. By immunohistochemistry four monoclonal antibodies detected bovine coronavirus and elk coronavirus in formalin-fixed intestinal tissues. Antinucleoprotein monoclonal antibodies were found to be better at ruminant coronavirus detection than the anti-spike protein monoclonal antibodies. Because nucleoprotein is a more abundant antigen than spike protein in infected cells, this was not an unexpected finding.

Small molecule potent IRAK4 inhibitors from a novel bicyclic heterocycle class were designed and synthesized based on hits identified from Aurigene’s compound library. The advanced lead compound, CA-4948, demonstrated good cellular activity in ABC DLBCL and AML cell lines. Inhibition of TLR signaling leading to decreased IL-6 levels was also observed in whole blood assays. CA-4948 demonstrated moderate to high selectivity in a panel of 329 kinases as well as exhibited desirable ADME and PK profiles including good oral bioavailability in mice, rat, and dog and showed >90% tumor growth inhibition in relevant tumor models with excellent correlation with in vivo PD modulation. CA-4948 was well tolerated in toxicity studies in both mouse and dog at efficacious exposure. The overall profile of CA-4948 prompted us to select it as a clinical candidate for evaluation in patients with relapsed or refractory hematologic malignancies including non-Hodgkin lymphoma and acute myeloid leukemia.