The majority of glioblastomas (GBMs) recur shortly after tumor resection and recurrent tumors differ significantly from newly diagnosed GBMs, phenotypically and genetically. In this study, using a Gl261-C57Bl/6 mouse glioma implantation model, we identified significant upregulation of proline-rich tyrosine kinase Pyk2 and focal adhesion kinase (FAK) phosphorylation levels-pPyk2 (579/580) and pFAK (925)-without significant modifications in total Pyk2 and FAK protein expression in tumors regrown after surgical resection, compared with primary implanted tumors. Previously, we demonstrated that Pyk2 and FAK are involved in the regulation of tumor cell invasion and proliferation and are associated with reduced overall survival.
View Article and Find Full Text PDFBackground: The development of resistance to temozolomide (TMZ), a standard chemotherapeutic, limits the effective treatment of glioblastoma (GBM). Focal adhesion kinase (FAK) and proline rich tyrosine kinase 2 (Pyk2) regulate proliferation and invasion of GBM cells. We found that TMZ activates FAK and Pyk2 signaling in GBM.
View Article and Find Full Text PDFGlioblastoma is the most aggressive brain cancer and is highly infiltrated with cells of myeloid lineage (TIM) that support tumor growth and invasion. Tumor resection is the primary treatment for glioblastoma; however, the activation state of TIM at the site of tumor resection and its impact on glioma regrowth are poorly understood. Using the C57BL/6/GL261 mouse glioma implantation model, we investigated the state of TIM in the tumor resection area during the post-surgical period.
View Article and Find Full Text PDFImmunostaining with specific antibodies has shown that innate amyloid beta (Aβ) is accumulated naturally in glioma tumors and nearby blood vessels in a mouse model of glioma. In immunofluorescence images, Aβ peptide coincides with glioma cells, and enzyme-linked immunosorbent assay (ELISA) have shown that Aβ peptide is enriched in the membrane protein fraction of tumor cells. ELISAs have also confirmed that the Aβ(1-40) peptide is enriched in glioma tumor areas relative to healthy brain areas.
View Article and Find Full Text PDFIn this study, we identified the proton-coupled folate transporter (PCFT) as a route for targeted delivery of drugs to some gliomas. Using the techniques of confocal imaging, quantitative reverse transcription-polymerase chain reaction (qRT-PCR), and small interfering (siRNA) knockdown against the PCFT, we demonstrated that Gl261 and A172 glioma cells, but not U87 and primary cultured astrocytes, express the PCFT, which provides selective internalization of folic acid (FA)-conjugated cytochrome c-containing nanoparticles (FA-Cyt c NPs), followed by cell death. The FA-Cyt c NPs (100 µg/mL), had no cytotoxic effects in astrocytes but caused death in glioma cells, according to their level of expression of PCFT.
View Article and Find Full Text PDFPatients infected with human immunodeficiency virus (HIV) are more prone to developing cancers, including glioblastomas (GBMs). The median survival for HIV positive GBM patients is significantly shorter than for those who are uninfected, despite the fact that they receive the same treatments. The nature of the GBM⁻HIV association remains poorly understood.
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