n, migration, and angiogenesis 22277057 in GBM. Additionally, proliferating endothelial cells in the brain are known to express chondroitin sulfate, suggesting a potential interaction between tumor and nascent vessels. CD97 is expressed in thyroid, gastric, esophageal, pancreatic, and colorectal cancers. It has been shown to correlate with lymph node invasion in thyroid cancer and poor clinical stage in colorectal cancer. Within tumors, expression of CD97 is generally highest at the invasive front or leading edge. Functionally, CD97 has been shown to confer an invasive phenotype and stimulate angiogenesis. CD97 was CD97 in Glioblastoma recently implicated in GBM after suppression of Wilms tumor 1 resulted in downregulation of the CD97 
gene product. Two other members of the EGF-TM7 family, EMR2 and EMR3, have also been identified in GBM, adding to evidence that this family may play an important role in glioma biology. We present data characterizing the expression and function of CD97 in human GBM. Using siRNA knockdown, we show that CD97 confers in invasive and migratory phenotype, but has no effect on cell proliferation. Using gene expression-based Kaplan-Meier analysis, we show that CD97 confers a poor prognosis in GBM and is associated with decreased survival. These findings provide impetus to further characterize the role of CD97 in glioma and determine its utility as a potential therapeutic target. Signaling, #2118). Membranes were washed in TBST then incubated with secondary antibody conjugated to horseradish peroxidase diluted to 1:2,000 in 5% milk. Membranes were then washed and developed using the Amersham ECL Western blotting detection system. Immunocytochemistry Cells were plated onto 12 mm cover glass at a density of 2.56105 cells/cover glass, then cultured for 2 days until reaching 80%90% confluence. After a brief wash with Dulbecco’s modified PBS, cells were fixed with 4% formaldehyde for 5 minutes at room 23237488 temperature. Cells were permeabilized with cold methanol, then blocked in DPBS containing 5% FBS, 2 mg/ml BSA, and 0.1% Triton X-100 for 1 hour at room temperature. Slides were incubated with a 1:100 dilution of rabbit anti-CD97 or rabbit anti-a tubulin antibody for 1 hour at room temperature, followed by incubation with a 1:250 dilution of goat anti-rabbit IgG conjugated to Alexa FluorH 488 for 1 hour. After 5 washes with DPBS, specimens were mounted on slides using a DAPI-containing mounting medium. Confocal images were generated on a Zeiss LSM 510 META laser-scanning microscope. Methods Cell Culture Primary glioblastoma cell lines were established from surgical specimens acquired at our institution from 2 surgeons. All research activities were approved by the University of California, San Francisco Committee on Human Research, our institutional review board for human research, with both written and verbal consent provided from patients. Freshly resected tumors, pathologically confirmed as GBM, were minced with a sterile scalpel and chemically dissociated in Papain at 20 units/ml for 20 minutes at 37uC. The dissociated tissue was filtered through a 70 mM cell strainer and the remaining cell suspension plated in RPMI-1640 media with 2 g/L glucose, 0.3 g/L L-glutamine, 2 g/L order Vorapaxar NaHCO3, 25 mM HEPES, 10% fetal bovine serum, 1% non-essential amino acids, 1% sodium pyruvate, and 1% penicillin/streptomycin. The human glioma cell lines U251, U87MG, and G55 were provided by Dr. Russell Pieper at UCSF. These cells were grown in Dulbecco’s Mo