Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0017638 (glioma)
 30,880 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Several anticancer drugs are ineffective against brain tumor and do not impact patient survival because they fail to cross the blood-brain tumor barrier (BTB) effective levels. One such agent temozolomide is commonly used in brain tumor patients, which works better when combined with radiation or other anticancer agents. Likewise, trastuzumab (Herceptin, Her-2 inhibitor), which might be effective against Her2/neu over expressing gliomas may work well when combined with temozolomide. Nonetheless, both drugs do not cross the BTB to significantly impact patient survival. Beforehand we showed that potassium channel agonists when intracarotidly administered increased carboplatin and Her-2 antibody delivery in animal glioma models by triggering formation of brain vascular endothelial transcytotic vesicles. In this study, we investigated whether, intravenously administered, ATP-sensitive potassium channel (K(ATP)) activator (minoxidil sulfate; MS) increases temozolomide and Herceptin delivery to brain tumors to induce anti-tumor activity and increase survival in nude mice with Glioblastoma multiforme (GBM) cells. The results clearly demonstrate that when given intravenously temozolomide crosses BTB at a relatively low amount while Herceptin failed to cross the BTB. However, MS co-infusion with [(14)C]-temozolomide or fluorescently labeled-Herceptin resulted in improved and selective drug delivery to brain tumor. We also showed that combination treatment with temozolomide and Herceptin has enhanced anti-tumor effect which was more prominent than that of either treatment alone in increasing the survival in mice with GBM when co-infused with MS. Therefore, brain tumor patients may be benefited when anti-neoplastic agent delivery is increased selectively to the brain tumors using KATP channel agonists.
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PMID:Activation of KATP channels increases anticancer drug delivery to brain tumors and survival. 1902 30

Most anticancer drugs fail to impact patient survival since they fail to cross the blood-brain tumor barrier (BTB) at therapeutic levels. For example, Temozolomide (TMZ) exhibits some antitumor activity against brain tumors, so does Trastuzumab (Herceptin, Her-2 inhibitor), which might be effective against Her2 neu overexpressing gliomas. Nevertheless, intact BTB and active efflux system may prevent their entry to brain tumors. Previously we have shown that potassium channel agonists increased carboplatin and Her-2 neu antibody delivery in animal glioma models. Here, we studied whether potassium channel agonist increase TMZ and Herceptin delivery across the BTB to elicit antitumor activity and increase survival in nude mice with human glial tumor. The K(Ca) channel activity and expression was also evaluated in human glioma tissues. We administered NS-1619, calcium-dependent potassium (K(Ca)) channel agonist, with [(14)C]-TMZ, and quantified TMZ delivery. The results clearly demonstrate that when given systemically both TMZ and Herceptin do not cross the BTB in significant amounts, however, NS-1619 co-infusion with [(14)C]-TMZ and Herceptin resulted in enhanced drug delivery to brain-tumor cells. The combination treatment of TMZ and Herceptin also showed improved antitumor effect which was more prominent than that of either treatment alone in increasing the survival in mice with brain tumor, when co-infused with K(Ca) channel agonists. In conclusion, K(Ca) channel agonists may benefit brain tumor patients by increasing anti-neoplastic agent's delivery to brain tumors. A clinical outcome of this research is the discovery of a novel drug delivery system that circumvents the BBB/BTB to benefit brain tumor patients.
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PMID:Modulation of KCa channels increases anticancer drug delivery to brain tumors and prolongs survival in xenograft model. 1973 31