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

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

Maternal mortality and fetal loss in GPCMV-infected guinea pigs.

A<p>Fetal loss data is only from surviving dams.</p

Viral kinetics of GPCMV during congenital infection.

A<p>SG, salivary glands from pregnant dams.</p>B<p>NAb, dam's neutralizing antibody titer, expressed as serum dilution determined by qPCR.</p>C<p>virus detected by qPCR.</p>D<p>virus detected by nested PCR.</p>E<p>AF, amniotic fluid.</p>F<p>ND, not done.</p

Temporal relationship between placental and fetal infection over 21 days.

<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 represents an infected mother with the size of the glyph proportional to the number of infected placentas and/or fetuses recovered. The proportion of infected placentas (x-axis) and infected fetuses (y-axis) was determined by qPCR and nested PCR, respectively. Data was compiled from three separate experiments.</p