TMEFF2 Is a PDGF-AA Binding Protein with Methylation-Associated Gene Silencing in Multiple Cancer Types Including Glioma

BACKGROUND: TMEFF2 is a protein containing a single EGF-like domain and two follistatin-like modules. The biological function of TMEFF2 remains unclear with conflicting reports suggesting both a positive and a negative association between TMEFF2 expression and human cancers. METHODOLOGY/PRINCIPAL FINDINGS: Here we report that the extracellular domain of TMEFF2 interacts with PDGF-AA. This interaction requires the amino terminal region of the extracellular domain containing the follistatin modules and cannot be mediated by the EGF-like domain alone. Furthermore, the extracellular domain of TMEFF2 interferes with PDGF-AA-stimulated fibroblast proliferation in a dose-dependent manner. TMEFF2 expression is downregulated in human brain cancers and is negatively correlated with PDGF-AA expression. Suppressed expression of TMEFF2 is associated with its hypermethylation in several human tumor types, including glioblastoma and cancers of ovarian, rectal, colon and lung origins. Analysis of glioma subtypes indicates that TMEFF2 hypermethylation and decreased expression are associated with a subset of non-Proneural gliomas that do not display CpG island methylator phentoype. CONCLUSIONS/SIGNIFICANCE: These data provide the first evidence that TMEFF2 can function to regulate PDGF signaling and that it is hypermethylated and downregulated in glioma and several other cancers, thereby suggesting an important role for this protein in the etiology of human cancers

An interleukin-17-mediated paracrine network promotes tumor resistance to anti-angiogenic therapy.

Although angiogenesis inhibitors have provided substantial clinical benefit as cancer therapeutics, their use is limited by resistance to their therapeutic effects. While ample evidence indicates that such resistance can be influenced by the tumor microenvironment, the underlying mechanisms remain incompletely understood. Here, we have uncovered a paracrine signaling network between the adaptive and innate immune systems that is associated with resistance in multiple tumor models: lymphoma, lung and colon. Tumor-infiltrating T helper type 17 (T(H)17) cells and interleukin-17 (IL-17) induced the expression of granulocyte colony-stimulating factor (G-CSF) through nuclear factor κB (NF-κB) and extracellular-related kinase (ERK) signaling, leading to immature myeloid-cell mobilization and recruitment into the tumor microenvironment. The occurrence of T(H)17 cells and Bv8-positive granulocytes was also observed in clinical tumor specimens. Tumors resistant to treatment with antibodies to VEGF were rendered sensitive in IL-17 receptor (IL-17R)-knockout hosts deficient in T(H)17 effector function. Furthermore, pharmacological blockade of T(H)17 cell function sensitized resistant tumors to therapy with antibodies to VEGF. These findings indicate that IL-17 promotes tumor resistance to VEGF inhibition, suggesting that immunomodulatory strategies could improve the efficacy of anti-angiogenic therapy

A Neutralizing Anti-gH/gL Monoclonal Antibody Is Protective in the Guinea Pig Model of Congenital CMV Infection

<div><p>Human cytomegalovirus (HCMV) is the most common cause of congenital virus infection. Congenital HCMV infection occurs in 0.2–1% of all births, and causes birth defects and developmental abnormalities, including sensorineural hearing loss and developmental delay. Several key studies have established the guinea pig as a tractable model for the study of congenital HCMV infection and have shown that polyclonal antibodies can be protective <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1004060#ppat.1004060-Bratcher1" target="_blank">[1]</a>–<a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1004060#ppat.1004060-Chatterjee1" target="_blank">[3]</a>. In this study, we demonstrate that an anti-guinea pig CMV (GPCMV) glycoprotein H/glycoprotein L neutralizing monoclonal antibody protects against fetal infection and loss in the guinea pig. Furthermore, we have delineated the kinetics of GPCMV congenital infection, from maternal infection (salivary glands, seroconversion, placenta) to fetal infection (fetus and amniotic fluid). Our studies support the hypothesis that a neutralizing monoclonal antibody targeting an envelope GPCMV glycoprotein can protect the fetus from infection and may shed light on the therapeutic intervention of HCMV congenital infection in humans.</p></div

Multimodal Microvascular Imaging Reveals that Selective Inhibition of Class I PI3K Is Sufficient to Induce an Antivascular Response

The phosphatidylinositol 3-kinase (PI3K) pathway is a central mediator of vascular endothelial growth factor (VEGF)-driven angiogenesis. The discovery of small molecule inhibitors that selectively target PI3K or PI3K and mammalian target of rapamycin (mTOR) provides an opportunity to pharmacologically determine the contribution of these key signaling nodes in VEGF-A-driven tumor angiogenesis in vivo. This study used an array of microvascular imaging techniques to monitor the antivascular effects of selective class I PI3K, mTOR, or dual PI3K/ mTOR inhibitors in colorectal and prostate cancer xenograft models. Micro-computed tomography (micro-CT) angiography, dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), vessel size index (VSI) MRI, and DCE ultrasound (DCE-U/S) were employed to quantitatively evaluate the vascular (structural and physiological) response to these inhibitors. GDC-0980, a dual PI3K/mTOR inhibitor, was found to reduce micro-CT angiography vascular density, while VSI MRI demonstrated a significant reduction in vessel density and an increase in mean vessel size, consistent with a loss of small functional vessels and a substantial antivascular response. DCE-MRI showed that GDC-0980 produces a strong functional response by decreasing the vascular permeability/perfusion-related parameter, Ktrans. Interestingly, comparable antivascular effects were observed for both GDC-980 and GNE-490 (a selective class I PI3K inhibitor). In addition, mTOR-selective inhibitors did not affect vascular density, suggesting that PI3K inhibition is sufficient to generate structural changes, characteristic of a robust antivascular response. This study supports the use of noninvasive microvascular imaging techniques (DCE-MRI, VSI MRI, DCE-U/S) as pharmacodynamic assays to quantitatively measure the activity of PI3K and dual PI3K/mTOR inhibitors in vivo

Effect of 1968/GPFc antibody on maternal mortality and congenital GPCMV infection^A^B.

A<p>Pregnant guinea pigs were infected with 4×10³ PFU of IVP8 at the start of the 2^nd trimester.</p>B<p>Cumulative results at 21 days post-infection.</p>C<p>Virus detected by quantitative PCR.</p>D<p>Virus detected by nested PCR.</p>E<p>Antibody administered I.P. one day prior to infection at 8 mg/kg dose and then twice per week for 3 weeks with a total of six doses (see <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1004060#ppat-1004060-g005" target="_blank">Figure 5</a> for study scheme).</p>F<p>n/a, not applicable, no fetuses were alive at end of study.</p>G<p>Averaged in-house historical data from infected pregnant guinea pigs without antibody treatment.</p

Viral kinetics of fetal infection over 21 days plotted from three separate studies.

<p>43 pregnant guinea pigs were inoculated by subcutaneous injection with 4×10³ PFU of pathogenic stock IVP8 at day 21 gestation and sacrificed at 1, 3, 7, 11, 15, and 21 days post-infection. Each glyph (dot) represents the proportion of infected fetuses, with the size of the glyph proportional to the litter size. The solid lines represent the proportion of infected fetuses in a litter from a beta-binomial model fit to all three cohorts. The dashed segment of each line is extrapolated beyond the cohort data and is model based. See statistical section in methods for more details.</p

Determination of the timing of seroconversion.

<p>An antigen-based ELISA assay was used to monitor the anti-gB (A) or anti-gH/gL (B) IgG response in infected pregnant guinea pigs over 21 days. Two dilutions (1∶100- green, 1∶2700- purple) are graphed to display the range of reactivity of the anti-gB response. The positive control, day 12 positive serum, (1∶2700- red, average value from 5 different plates with 2 replicates per plate) consistently resulted in the linear range and near the middle of the dynamic range. Pre-immune samples were consistently at zero indicating the cut-off of the assay (an example is shown at d0 at 1∶100, blue). The 1∶2700 was not graphed for anti-gH/gL (B) due to lack of signal. The error bars represent standard deviation of the means calculated from the results of several animals at each time point (see methods for study details).</p