51. In vivo and in vitro properties of STX2484: a novel non-steroidal anti-cancer compound active in taxane-resistant breast cancer.
- Author
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Stengel C, Newman SP, Day JM, Chander SK, Jourdan FL, Leese MP, Ferrandis E, Regis-Lydi S, Potter BV, Reed MJ, Purohit A, and Foster PA
- Subjects
- Animals, Antineoplastic Agents, Phytogenic pharmacology, Apoptosis drug effects, Breast Neoplasms pathology, Cell Cycle drug effects, Cell Growth Processes drug effects, Cell Line, Tumor, Female, Humans, Immunohistochemistry, MCF-7 Cells, Mice, Mice, Inbred C57BL, Mice, Nude, Xenograft Model Antitumor Assays, Breast Neoplasms drug therapy, Isoquinolines pharmacology, Paclitaxel pharmacology, Sulfonic Acids pharmacology
- Abstract
Background: STX2484 is a novel non-steroidal compound with potent anti-proliferative activity. These studies aimed to identify STX2484's mechanism of action, in vivo efficacy and activity in taxane-resistant breast cancer models., Methods: Effects of STX2484 and paclitaxel on proliferation, cell cycle and apoptosis were assessed in vitro in drug-resistant (MCF-7(DOX)) and non-resistant cells (MCF-7(WT)). STX2484 efficacy in βIII tubulin overexpression in MCF-7 cells was also determined. Anti-angiogenic activity was quantified in vitro by a co-culture model and in vivo using a Matrigel plug assay. An MDA-MB-231 xenograft model was used to determine STX2484 efficacy in vivo., Results: STX2484 is a tubulin disruptor, which induces p53 expression, Bcl2 phosphorylation, caspase-3 cleavage, cell cycle arrest and apoptosis. In addition, STX2484 is a potent anti-angiogenic agent in vitro and in vivo. In breast cancer xenografts, STX2484 (20 mg kg(-1) p.o.) suppressed tumour growth by 84% after 35 days of daily dosing, with limited toxicity. In contrast to paclitaxel, STX2484 efficacy was unchanged in two clinically relevant drug-resistant models., Conclusions: STX2484 is an orally bioavailable microtubule-disrupting agent with in vivo anti-angiogenic activity and excellent in vivo efficacy with no apparent toxicity. Crucially, STX2484 has superior efficacy to paclitaxel in models of clinical drug resistance.
- Published
- 2014
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