Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C1658953 (tumor vasculature)
 2,390 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The phosphatidylinositol 3'-kinase (PI3k)/protein kinase B (PKB/Akt) signal transduction pathway plays a critical role in mediating endothelial cell survival and function during oxidative stress. The role of the PI3k/Akt signaling pathway in promoting cell viability was studied in vascular endothelial cells treated with ionizing radiation. Western blot analysis showed that Akt was rapidly phosphorylated in response to radiation in primary culture endothelial cells (human umbilical vascular endothelial cells) in the absence of serum or growth factors. PI3k consists of p85 and p110 subunits, which play a central upstream role in Akt activation in response to exogenous stimuli. The delta isoform of the p110 subunit is expressed in endothelial cells. We studied the effects of the p110delta specific inhibitor IC486068, which abrogated radiation-induced phosphorylation of Akt. IC486068 enhanced radiation-induced apoptosis in endothelial cells and reduced cell migration and tubule formation of endothelial cells in Matrigel following irradiation. In vivo tumor growth delay was studied in mice with Lewis lung carcinoma and GL261 hind limb tumors. Mice were treated with daily i.p. injections (25 mg/kg) of IC486068 during 6 days of radiation treatment (18 Gy). Combined treatment with IC486068 and radiation significantly reduced tumor volume as compared with either treatment alone. Reduction in vasculature was confirmed using the dorsal skinfold vascular window model. The vascular length density was measured by use of the tumor vascular window model and showed IC486068 significantly enhanced radiation-induced destruction of tumor vasculature as compared with either treatment alone. IC486068 enhances radiation-induced endothelial cytotoxicity, resulting in tumor vascular destruction and tumor control when combined with fractionated radiotherapy in murine tumor models. These findings suggest that p110delta is a therapeutic target to enhance radiation-induced tumor control.
 ...
PMID:A specific antagonist of the p110delta catalytic component of phosphatidylinositol 3'-kinase, IC486068, enhances radiation-induced tumor vascular destruction. 1525 60

Integrin-linked kinase (ILK) was assesed as a therapeutic target in glioblastoma xenograft models through multiple endpoints including treatment related changes in the tumor microenvironment. Glioblastoma cell lines were tested in vitro for sensitivity toward the small-molecule inhibitors QLT0254 and QLT0267. Cell viability, cell cycle, and apoptosis were evaluated using MTT assay, flow cytometry, caspase activation, and DAPI staining. Western blotting and ELISA were used for protein analysis (ILK, PKB/Akt, VEGF, and HIF-1alpha). In vivo assessment of growth rate, cell proliferation, BrdUrd, blood vessel mass (CD31 labeling), vessel perfusion (Hoechst 33342), and hypoxia (EF-5) was done using U87MG glioblastoma xenografts in RAG2-M mice treated orally with QLT0267 (200 mg/kg q.d.). ILK inhibition in vitro with QLT0254 and QLT0267 resulted in decreased levels of phospho-PKB/Akt (Ser473), secreted VEGF, G2-M block, and apoptosis induction. Mice treated with QLT0267 exhibited significant delays in tumor growth (treated 213 mm3 versus control 549 mm3). In situ analysis of U87MG tumor cell proliferation from QLT0267-treated mice was significantly lower relative to untreated mice. Importantly, VEGF and HIF-1alpha expression decreased in QLT0267-treated tumors as did the percentage of blood vessel mass and numbers of Hoechst 33342 perfused tumor vessels compared with control tumors (35% versus 83%). ILK inhibition with novel small-molecule inhibitors leads to treatment-associated delays in tumor growth, decreased tumor angiogenesis, and functionality of tumor vasculature. The therapeutic effects of a selected ILK inhibitor (QLT0267) should be determined in the clinic in cancers that exhibit dysregulated ILK, such as PTEN-null glioblastomas.
 ...
PMID:Suppression of VEGF secretion and changes in glioblastoma multiforme microenvironment by inhibition of integrin-linked kinase (ILK). 1820 10