noscapine and Glioma

Previously, we identified noscapine as a small molecule inhibitor of the hypoxia-inducible factor-1 pathway in hypoxic human glioma cells and human umbilical vein endothelial cells. Noscapine is a nontoxic ingredient in cough medicine currently used in clinical trials for patients with non-Hodgkin's lymphoma or chronic lymphocytic leukemia to assess antitumor efficacy. Here, we have evaluated the sensitivity of four human glioma cell lines to noscapine-induced apoptosis. Noscapine was a potent inhibitor of proliferation and inducer of apoptosis. Induction of apoptosis was associated with activation of the c-jun N-terminal kinase signaling pathway concomitant with inactivation of the extracellular signal regulated kinase signaling pathway and phosphorylation of the antiapoptotic protein Bcl-2. Noscapine-induced apoptosis was associated with the release of mitochondrial proteins apoptosis-inducing factor (AIF) and/or cytochrome c. In some glioma cell lines, only AIF release occurred without cytochrome c release or poly (ADP-ribose) polymerase cleavage. Knock-down of AIF decreased noscapine-induced apoptosis. Our results suggest the potential importance of noscapine as a novel agent for use in patients with glioblastoma owing to its low toxicity profile and its potent anticancer activity.

Topics: Apoptosis; Apoptosis Inducing Factor; Cell Division; Cell Line, Tumor; Cell Proliferation; Cyclin B; Cyclin B1; Cytochromes c; Glioma; Humans; MAP Kinase Signaling System; Noscapine; Proto-Oncogene Proteins c-bcl-2

To assess the effects of noscapine, a tubulin-binding drug, in combination with radiation in a murine glioma model.. The human T98G and murine GL261 glioma cell lines treated with noscapine, radiation, or both were assayed for clonogenic survival. Mice with established GL261 hind limb tumors were treated with noscapine, radiation, or both to evaluate the effect of noscapine on radioresponse. In a separate experiment with the same treatment groups, 7 days after radiation, tumors were resected and immunostained to measure proliferation rate, apoptosis, and angiogenic activity.. Noscapine reduced clonogenic survival without enhancement of radiosensitivity in vitro. Noscapine combined with radiation significantly increased tumor growth delay: 5, 8, 13, and 18 days for control, noscapine alone, radiation alone, and the combination treatment, respectively (p < 0.001). To assess the effect of the combination of noscapine plus radiation on the tumor vasculature, tubule formation by the murine endothelial 2H11 cells was tested. Noscapine with radiation significantly inhibited tubule formation compared with radiation alone. By immunohistochemistry, tumors treated with the combination of noscapine plus radiation showed a decrease in BrdU incorporation, an increase in apoptosis by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling, and a decrease in tumor vessel density compared with tumors treated with radiation alone.. Noscapine enhanced the sensitivity of GL261 glioma tumors to radiation, resulting in a significant tumor growth delay. An antiangiogenic mechanism contributed to the effect. These findings are clinically relevant, particularly in view of the mild toxicity profile of this drug.

Topics: Angiogenesis Inhibitors; Animals; Apoptosis; Bromodeoxyuridine; Cell Line, Tumor; Cell Proliferation; Combined Modality Therapy; Female; Glioma; Humans; In Situ Nick-End Labeling; Mice; Mice, Inbred C57BL; Neovascularization, Pathologic; Noscapine; Radiation Tolerance; Xenograft Model Antitumor Assays

Overexpression of hypoxia-inducible factor-1 (HIF-1) is a common feature in solid malignancies related to oxygen deficiency. Since increased HIF-1 expression correlates with advanced disease stage, increased angiogenesis and poor prognosis, HIF-1 and its signaling pathway have become targets for cancer chemotherapy. In this study, we identified noscapine to be a novel small molecule inhibitor of the HIF-1 pathway based on its structure-function relation-ships with HIF-1 pathway inhibitors belonging to the benzylisoquinoline class of plant metabolites and/or to microtubule binding agents. We demonstrate that noscapine treatment of human glioma U87MG and T98G cell lines exposed to the hypoxic mimetic agent, CoCl2, inhibits hypoxia-mediated HIF-1alpha expression and transcriptional activity as measured by decreased secretion of VEGF, a HIF-1 target gene. Inhibition of hypoxia-mediated HIF-1alpha expression was due, in part, to its ability to inhibit accumulation of HIF-1alpha in the nucleus and target it for degradation via the proteasome. One mechanism of action of microtubule binding agents is their antiangiogenic activity associated with disruption of endothelial tubule formation. We show that noscapine has similar properties in vitro. Thus, noscapine may possess novel antiangiogenic activity associated with two broad mechanisms of action: first, by decreasing HIF-1alpha expression in hypoxic tumor cells, upregulation of target genes, such as VEGF, would be decreased concomitant with its associated angiogenic activity; second, by inhibiting endothelial cells from forming blood vessels in response to VEGF stimulation, it may limit the process of neo-vascularization, correlating with antitumor activity in vivo. For more than 75 years, noscapine has traditionally been used as an oral cough suppressant with no known toxic side effects in man. Thus, the studies reported here have found a novel function for an old drug. Given its low toxicity profile, its demonstrated antitumor activity in several animal models of cancer and its potential to inhibit the HIF-1 pathway, noscapine should be considered as an antiangiogenic chemotherapy for glioma.

Topics: Angiogenesis Inhibitors; Brain Neoplasms; Cell Line, Tumor; Cobalt; DNA Primers; Gene Expression Regulation, Neoplastic; Glioma; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Neovascularization, Pathologic; Noscapine; RNA, Neoplasm

Radiation therapy after surgical resection is the approved treatment of gliomas, and survival benefits are reported with taxane-based chemotherapy. We investigated whether these regimes could be augmented with blood-brain barrier permeable drugs, N and D. Noscapine is an opioid antitussive, which acts anti cancer via blocking microtubule dynamics. Diltiazem is a calcium channel-blocking cardiac antiarrythmic, which also blocks tumor growth and P-glycoprotein.. Effects of N (11.1 micromol/L), D (11.1 micromol/L), and T (11.7 micromol/L) were monitored in C6 glioma cells via S phase, colony formation, and fine structure analysis.. Taxol depleted S phase from 35.2% to 12.2%. Both N and D synergistically augmented T-mediated S-phase depletion, and they also effectively reduced colonies, which were more potent by N by 49%. Taxol reduced colonies by 98%, and there were almost no surviving colonies in copresence of T with either N or D. Colony reduction by radiotherapy was increased strongly by T and significantly by N. Taxol and radiation profoundly increased number of mitochondria. Both D and N suppressed this increase via myelinosis and autophagy.. Noscapine and D should be further tested in animal models because of their potential and already-present clinical applicability.

Topics: Antineoplastic Combined Chemotherapy Protocols; Apoptosis; ATP Binding Cassette Transporter, Subfamily B, Member 1; Cell Line, Tumor; Diltiazem; Drug Synergism; Glioma; Humans; Microscopy, Electron; Mitochondria; Noscapine; Paclitaxel; S Phase; Tumor Stem Cell Assay