Abstract
Previously, we reported that 6,7-dimethoxy-3-(3-methoxyphenyl)isoquinolin-1-amine (CWJ-082) has potent cytotoxic effects on various cancer cells, but the underlying molecular mechanism responsible was not determined. In the present study, CWJ-082 caused cervical cancer cell cycle arrest at the G2/M phase and subsequent caspase-dependent apoptosis. The mitotic arrest caused by CWJ-082 found to be due to increases in the activation of cyclin-dependent kinase 1/cyclin B1 complex and the phosphorylation of histone H3. In addition, CWJ-082 induced the phosphorylation of BubR1 and the association between mitotic arrest deficient 2 (Mad2) and cell division cycle protein 20. These findings suggested that CWJ-082 activated the mitotic spindle checkpoint. Furthermore, knockdown of the spindle checkpoint proteins BubR1 or Mad2 using specific small interfering RNAs significantly reduced CWJ-082-induced mitotic cell accumulation and apoptosis. In addition, CWJ-082 induced the appearance of spindle abnormalities by inducing α-tubulin polymerization. In BALB/c(nu/nu) mice bearing a HeLa xenograft, CWJ-082 significantly inhibited tumor growth. Taken together, these results suggest that CWJ-082 inhibits cell growth via mitotic arrest by activating the mitotic spindle checkpoint and by inducing α-tubulin polymerization and that these events ultimately lead to the apoptosis of human cervical cancer cells and inhibit tumor growth in HeLa xenograft mice.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Antineoplastic Agents / pharmacology
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Apoptosis / drug effects*
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Apoptosis / genetics
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CDC2 Protein Kinase / genetics
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CDC2 Protein Kinase / metabolism
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Caspases / genetics
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Caspases / metabolism
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Cdc20 Proteins / genetics
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Cdc20 Proteins / metabolism
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Cell Cycle Checkpoints / drug effects*
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Cell Cycle Checkpoints / genetics
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Cell Division / drug effects
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Cell Division / genetics
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Cell Line, Tumor
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Cyclin B1 / genetics
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Cyclin B1 / metabolism
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Female
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G2 Phase / drug effects
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G2 Phase / genetics
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HeLa Cells
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Histones / genetics
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Histones / metabolism
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Humans
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Isoquinolines / pharmacology*
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M Phase Cell Cycle Checkpoints / drug effects*
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M Phase Cell Cycle Checkpoints / genetics
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Mad2 Proteins / genetics
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Mad2 Proteins / metabolism
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Mice
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Mice, Inbred BALB C
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Mice, Nude
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Microtubules / genetics
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Microtubules / metabolism
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Mitosis / drug effects*
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Mitosis / genetics
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Phosphorylation / drug effects
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Phosphorylation / genetics
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Protein Serine-Threonine Kinases / genetics
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Protein Serine-Threonine Kinases / metabolism
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Tubulin / genetics
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Tubulin / metabolism
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Uterine Cervical Neoplasms / genetics*
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Uterine Cervical Neoplasms / metabolism
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Uterine Cervical Neoplasms / pathology
Substances
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Antineoplastic Agents
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CCNB1 protein, human
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Cdc20 Proteins
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Cyclin B1
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Histones
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Isoquinolines
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MAD2L1 protein, human
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Mad2 Proteins
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Tubulin
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CDC20 protein, human
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BUB1 protein, human
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Protein Serine-Threonine Kinases
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CDC2 Protein Kinase
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Caspases