OSU-03012 and Viagra Treatment Inhibits the Activity of Multiple Chaperone Proteins and Disrupts the Blood-Brain Barrier: Implications for Anti-Cancer Therapies.
Abstract
We examined the interaction between OSU-03012 (also called AR-12) with phosphodiesterase 5 (PDE5) inhibitors to determine the role of the chaperone glucose-regulated protein (GRP78)/BiP/HSPA5 in the cellular response. Sildenafil (Viagra) interacted in a greater than additive fashion with OSU-03012 to kill stem-like GBM cells. Treatment of cells with OSU-03012/sildenafil: abolished the expression of multiple oncogenic growth factor receptors and plasma membrane drug efflux pumps and caused a rapid degradation of GRP78 and other HSP70 and HSP90 family chaperone proteins. Decreased expression of plasma membrane receptors and drug efflux pumps was dependent upon enhanced PERK-eIF2α-ATF4-CHOP signaling and was blocked by GRP78 over-expression. In vivo OSU-03012/sildenafil was more efficacious than treatment with celecoxib and sildenafil at killing tumor cells without damaging normal tissues and in parallel reduced expression of ABCB1 and ABCG2 in the normal brain. The combination of OSU-03012/sildenafil synergized with low concentrations of sorafenib to kill tumor cells, and with lapatinib to kill ERBB1 over-expressing tumor cells. In multiplex assays on plasma and human tumor tissue from an OSU-03012/sildenafil treated mouse, we no...Continue Reading
References
Citations
Methods Mentioned
Related Concepts
Related Feeds
Blood Brain Barrier Chips
The blood brain barrier (BBB) is comprised of endothelial cells that regulate the influx and outflux of plasma concentrations. Lab-on-a-chip devices allow scientists to model diseases and mechanisms such as the passage of therapeutic antibodies across the BBB. Discover the latest research on BBB chips here.
Blood Brain Barrier Regulation in Health & Disease
The blood brain barrier is essential in regulating the movement of molecules and substances in and out of the brain. Disruption to the blood brain barrier and changes in permeability allow pathogens and inflammatory molecules to cross the barrier and may play a part in the pathogenesis of neurodegenerative disorders. Here is the latest research in this field.
Blood Brain Barrier
The blood brain barrier is a border that separates blood from cerebrospinal fluid. Discover the latest search on this highly selective semipermeable membrane here.
Cell Signaling by Tyrosine Kinases
Receptor tyrosine kinases (RTKs) are the high-affinity cell surface receptors for many polypeptide growth factors, cytokines, and hormones. RTKs have been shown not only to be key regulators of normal cellular processes but also to have a critical role in the development and progression of many types of cancer. Discover the latest research on cell signaling and RTK here.