Abstract
We have previously synthesized a series of 7-aroylaminoindoline-1-sulfonamides as a novel class of antitubulin agents. Here we show that one of these new compounds, N-[1-(4-methoxybenzenesulfonyl)-2,3-dihydro-1H-indol-7-yl]-isonicotinamide (J30), is potently effective against various resistant and nonresistant cancer cell lines despite the status of multidrug resistance, multidrug-resistance associated protein, or other resistance factors in vitro. J30 inhibits assembly of purified tubulin by strongly binding to the colchicine-binding site. Western blot and immunofluorescence experiments demonstrate that J30 depolymerizes microtubules in the KB cell line, resulting in an accumulation of G2/M phase cells. Further studies indicate that J30 causes cell cycle arrest, as assessed by flow analyses and the appearance of MPM-2 (a specific mitotic marker), and is associated with up-regulation of cyclin B1, phosphorylation of Cdc25C, and dephosphorylation of Cdc2. J30 also causes Bcl-2 phosphorylation, cytochrome c translocation, and activation of the caspase-9 and caspase-3 cascades. These findings suggest that the J30-mediated apoptotic signaling pathway depends on caspases and mitochondria. Finally, we show that oral administration of J30 significantly inhibits tumor growth in NOD/scid mice bearing human oral, gastric, and drug-resistant xenografts. Together, our results suggest that J30 has potential as a chemotherapeutic agent for treatment of various malignancies.
Footnotes
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This work was supported in part by grants from National Health Research Institutes, Taipei, Taiwan (NHRI Intramural Grant CA-095-PP-04), and the National Science Council, Taipei, Taiwan (NSC 95-2752-B-400-001-PAE).
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J.P.L. and K.S.H. contributed equally to this work.
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Article, publication date, and citation information can be found at http://jpet.aspetjournals.org.
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doi:10.1124/jpet.107.126680.
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ABBREVIATIONS: MDR, multidrug resistance; Pgp, P-glycoprotein; MRP, multidrug-resistance associated protein; HMN-214, ((E)-4-{2-[2-(N-acetyl-N-[4-methoxybenzenesulfonyl]amino) stilbazole]}1-oxide), E7070, N-(3-chloro-7-indolyl)-1,4-benzenedisulfonamide; E7010, N-[2-[(4-hydroxyphenyl) amino]-3-pyridinyl]-4-methoxybenzenesulfonamide; J30, N-[1-(4-methoxy-benzenesulfonyl)-2,3-dihydro-1H-indol-7-yl]-isonicotinamide, CPT, camptothecin; VP16, etoposide; HRP, horseradish peroxidase; PARP, poly(ADP-ribose) polymerase; FITC, fluorescent isothiocyanate; SPA, scintillation proximity assay; PIPES, 1,4-piperazinediethanesulfonic acid; PMSF, phenylmethylsulfonyl fluoride; NP-40, Nonidet P-40; PAGE, polyacrylamide gel electrophoresis; PBST, phosphate-buffered saline with 0.1% Tween 20; PI, propidium iodide; NOD/scid mice, nonobese diabetic/severe combined immune-deficiency mice.
- Received June 5, 2007.
- Accepted July 26, 2007.
- The American Society for Pharmacology and Experimental Therapeutics
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