PubMed · 10857088
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
J Thalhamer, P Hammerl, A Hartl. 2000. Nitrocellulose-based immunoaffinity chromatography.. https://doi.org/10.1007/978-1-60327-261-2_9
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
In glioblastoma (GBM), the most frequent and lethal brain tumor, therapies suppressing recurrently altered signaling pathways failed to extend survival. However, in patient subsets, specific genetic lesions can confer sensitivity to targeted agents. By exploiting an integrated model based on patient-derived stem-like cells, faithfully recapitulating the original GBMs in vitro and in vivo, here, we identify a human GBM subset (∼9% of all GBMs) characterized by ERBB3 overexpression and nuclear accumulation. ERBB3 overexpression is driven by inheritable promoter methylation or post-transcriptional silencing of the oncosuppressor miR-205 and sustains the malignant phenotype. Overexpressed ERBB3 behaves as a specific signaling platform for fibroblast growth factor receptor (FGFR), driving PI3K/AKT/mTOR pathway hyperactivation, and overall metabolic upregulation. As a result, ERBB3 inhibition by specific antibodies is lethal for GBM stem-like cells and xenotransplants. These findings highlight a subset of patients eligible for ERBB3-targeted therapy.
We screened a human lymphocyte cDNA library using the yeast two-hybrid system and an automodification domain of PARP as a probe. The DNA sequence of an isolated clone (clone 3-9) was identical to the partial cDNA sequence of the human ribosomal protein S3a. We confirmed that PARP interacts with clone 3-9 by performing binding studies using a GST-3-9 fusion protein as bait. We also demonstrated that native S3a in nuclear extracts of HL-60 cells interacts with the automodification domain of PARP and that PARP from nuclear extracts is coprecipitated with the GST-3-9 fusion protein. Furthermore, we demonstrated that Bcl-2 interacts with PARP in association with S3a and that the interaction of S3a and Bcl-2 with PARP causes a significant decrease in PARP activity. Since Bcl-2 failed to inhibit PARP activity in the absence of S3a, we suggest that Bcl-2 together with S3a prevents apoptosis probably by inhibiting PARP activity.
In chronic inflammatory diseases, the endothelium is an attractive target for pharmacological intervention because it plays an important role in leukocyte recruitment. Hence, inhibition of endothelial cell activation and consequent leukocyte infiltration may improve therapeutic outcome in these diseases. We report on a drug targeting strategy for the selective delivery of the anti-inflammatory drug dexamethasone to activated endothelial cells, using an E-selectin-directed drug-Ab conjugate. Dexamethasone was covalently attached to an anti-E-selectin Ab, resulting in the so-called dexamethasone-anti-E-selectin conjugate. Binding of the conjugate to E-selectin was studied using surface plasmon resonance and immunohistochemistry. Furthermore, internalization of the conjugate was studied using confocal laser scanning microscopy and immuno-transmission electron microscopy. It was demonstrated that the dexamethasone-anti-E-selectin conjugate, like the unmodified anti-E-selectin Ab, selectively bound to TNF-alpha-stimulated endothelial cells and not to resting endothelial cells. After binding, the conjugate was internalized and routed to multivesicular bodies, which is a lysosome-related cellular compartment. After intracellular degradation, pharmacologically active dexamethasone was released, as shown in endothelial cells that were transfected with a glucocorticoid-responsive reporter gene. Furthermore, intracellularly delivered dexamethasone was able to down-regulate the proinflammatory gene IL-8. In conclusion, this study demonstrates the possibility to selectively deliver the anti-inflammatory drug dexamethasone into activated endothelial cells, using an anti-E-selectin Ab as a carrier molecule.