Novel Microtubule-Disrupting Indole-Based Chalcones That Induce Cell Death in Glioblastoma
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University of Toledo Health Science Campus / OhioLINK
2017
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| Online Access: | http://rave.ohiolink.edu/etdc/view?acc_num=mco1513072908428639 |
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ndltd-OhioLink-oai-etd.ohiolink.edu-mco15130729084286392021-08-03T07:05:08Z Novel Microtubule-Disrupting Indole-Based Chalcones That Induce Cell Death in Glioblastoma Du, Shengnan Biomedical Research Microtubule-Disrupting Glioblastoma Chalcones The extremely poor prognosis of Glioblastoma multiforme highlights the urgent need for more efficient drugs to treat this disease. We have developed a series of small molecules that induce a novel non-apoptotic cell death mechanism, methuosis, in cancer cells. During the structure-activity relationship study of methuosis-inducing compounds, we identified a group of unique chalcone derivatives with more potent anti-tumor activity. The lead compound is 3-(6-methoxy-2-methyl-1H-indol-3-yl)-1-(4-pyridinyl)-2-propene-1-one (6-MOMIPP). 6-MOMIPP exhibits potent anti-proliferative and cytotoxic activity in glioblastoma, melanoma, and lung cancer cell lines at concentrations in the nanomolar range. However, cells treated with the new class of compounds did not morphologically resemble cells undergoing methuosis. By 24 h, 6-MOMIPP causes the majority of cells to round up from the culture dish and arrest in mitosis. By 48 h, cell viability is greatly reduced, correlating with activation of caspases 9, 7, and 3. Caspase inhibitors block the cell death induced by 6-MOMIPP, suggesting that cell death is caspase-dependent. Phase contrast images show that the few cells remaining alive after treatment with 6-MOMIPP are giant, flat, and multiple micronucleated. Whole cell tubulin polymerization assay shows that 6-MOMIPP significantly reduces the amount of polymerized tubulin in living cells. Immunofluorescence staining of microtubules reveals microtubule disruption in U251 cells after treatment with 6-MOMIPP at a concentration of 250 nM or higher. In vitro scintillation proximity assay and EBI cross-linking studies of ß-tubulin in intact cells both reveal that 6-MOMIPP binds to tubulin on the colchicine binding site. Blocking Cdk1 activity with BMS-265246 greatly reduces cell death induced by 6-MOMIPP, but has no effect on the mitotic arrest, suggesting that blockage of metaphase-anaphase transition by prolonged Cdk1 activation is responsible for the 6-MOMIPP-induced death. Treatment of cells for 24 h with 6-MOMIPP induces phosphorylation of Bcl-2 and Bcl-xL, which could be eliminated by inhibiting Cdk1, suggesting that Cdk1 plays a key role in phosphorylation of the anti-apoptotic Bcl proteins. Cell death induced by 6-MOMIPP is also accompanied by activation of JNK and its downstream substrate c-Jun. Blocking JNK activity with SP600125 reduces the percentage of dead cells, indicating that JNK activation may contribute to the cell death. Cell viability studies have shown the toxicity of 6-MOMIPP is substantially reduced in quiescent human fibroblasts, HUVEC (human umbilical vein endothelial cells) and rat neuronal progenitor cells. Pharmacokinetic studies in mice show that 6-MOMIPP attains brain concentrations that are nearly equal to plasma concentrations at time points up to 8 h after intraperitoneal (i.p.) injection, suggesting that 6-MOMIPP readily crosses the blood-brain barrier. 6-MOMIPP administration at 20 mg/kg every 12 h for 12-15 days significantly decreases the growth of glioblastoma in subcutaneous and intracranial xenograft models without notable toxicities, suggesting that 6-MOMIPP has good anti-tumor activity in vivo. These preliminary findings suggest that 6-MOMIPP merits further preclinical evaluation as a potential therapeutic agent for primary and metastatic brain tumors. 2017 English text University of Toledo Health Science Campus / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=mco1513072908428639 http://rave.ohiolink.edu/etdc/view?acc_num=mco1513072908428639 unrestricted This thesis or dissertation is protected by copyright: some rights reserved. It is licensed for use under a Creative Commons license. Specific terms and permissions are available from this document's record in the OhioLINK ETD Center. |
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NDLTD |
| language |
English |
| sources |
NDLTD |
| topic |
Biomedical Research Microtubule-Disrupting Glioblastoma Chalcones |
| spellingShingle |
Biomedical Research Microtubule-Disrupting Glioblastoma Chalcones Du, Shengnan Novel Microtubule-Disrupting Indole-Based Chalcones That Induce Cell Death in Glioblastoma |
| author |
Du, Shengnan |
| author_facet |
Du, Shengnan |
| author_sort |
Du, Shengnan |
| title |
Novel Microtubule-Disrupting Indole-Based Chalcones That Induce Cell Death in Glioblastoma |
| title_short |
Novel Microtubule-Disrupting Indole-Based Chalcones That Induce Cell Death in Glioblastoma |
| title_full |
Novel Microtubule-Disrupting Indole-Based Chalcones That Induce Cell Death in Glioblastoma |
| title_fullStr |
Novel Microtubule-Disrupting Indole-Based Chalcones That Induce Cell Death in Glioblastoma |
| title_full_unstemmed |
Novel Microtubule-Disrupting Indole-Based Chalcones That Induce Cell Death in Glioblastoma |
| title_sort |
novel microtubule-disrupting indole-based chalcones that induce cell death in glioblastoma |
| publisher |
University of Toledo Health Science Campus / OhioLINK |
| publishDate |
2017 |
| url |
http://rave.ohiolink.edu/etdc/view?acc_num=mco1513072908428639 |
| work_keys_str_mv |
AT dushengnan novelmicrotubuledisruptingindolebasedchalconesthatinducecelldeathinglioblastoma |
| _version_ |
1719453291583111168 |