CIL-102 interacts with microtubule polymerization and causes mitotic arrest following apoptosis in the human prostate cancer PC-3 cell line
Journal
Journal of Biological Chemistry
Journal Volume
280
Journal Issue
4
Pages
2771-2779
Date Issued
2005
Author(s)
Abstract
There have been no therapeutic agents that provide a survival advantage in hormone-refractory prostate cancer. Recently, the Food and Drug Administration approved docetaxel combined with prednisone for the treatment of patients with advanced metastatic prostate cancer, and it does show a survival benefit. Hence, anti-microtubule drugs might be of benefit in chemotherapy of hormone-refractory prostate cancer. We used metastatic hormone-refractory prostate cancer PC-3 cells to investigate potential molecular mechanisms for CIL-102, a semisynthetic alkaloid derivative. 3-(4,5-Dimethylthiazol-2-yl)-2,5- diphenylte-trazolium bromide and sulforhodamine B assays indicated that CIL-102 inhibits cell growth dose-dependently. Immunofluorescence microscopy and in vitro tubulin assembly assays indicated that CIL-102 binds to tubulin and disrupts microtubule organization. Flow cytometry showed that CIL-102 causes cells to accumulate in G2/M phase and subG0/G1 phase. CIL-102-induced apoptosis was also characterized by immunofluorescence microscopy. Western blotting and kinase assays showed that CIL-102 exposure induced up-regulation of cyclin B1 and p34cdc2 kinase activity and olomoucine, a p34cdc2 inhibitor, profoundly reduced the number of cells accumulated in mitotic phase. Moreover, Bcl-2 phosphorylation, Cdc25C phosphorylation, and survivin expression were increased. CIL-102-induced apoptosis was associated with activation of caspase-3, but a noncaspase pathway may also be involved, since benzyloxycarbonyl-VAD-fluoromethyl ketone, a pancaspase inhibitor, only partially inhibited the apoptosis, and apoptosis-inducing factor was translocated from mitochondria to cytosol. We conclude that CIL-102 induces mitotic arrest and apoptosis by binding to tubulin and inhibiting tubulin polymerization. CIL-102 causes mitotic arrest, at least partly, by modulating cyclin-dependent kinases and then apoptosis executed by caspase and noncaspase pathways.
SDGs
Other Subjects
Chemotherapy; Fluorescence; Hormones; Immunology; Patient monitoring; Tumors; Anti-microtubule drugs; Immunofluorescence microscopy; Mitotic phase; Prostate cancer; Cells; 3 (4,5 dimethyl 2 thiazolyl) 2,5 diphenyltetrazolium bromide; alkaloid derivative; apoptosis inducing factor; benzyloxycarbonylvalylalanylaspartyl fluoromethyl ketone; caspase 3; caspase inhibitor; CIL 102; cyclin B1; cyclin dependent kinase 1; docetaxel; olomoucine; prednisone; protein bcl 2; sulforhodamine B; survivin; tubulin; unclassified drug; apoptosis; article; cell growth; cell line; chemical binding; chromosome translocation; cytosol; dose response; enzyme activation; enzyme activity; flow cytometry; food and drug administration; human; human cell; immunofluorescence microscopy; in vitro study; microtubule assembly; mitosis; mitosis inhibition; molecular interaction; molecular mechanics; priority journal; prostate cancer; protein phosphorylation; upregulation; Western blotting; Amino Acid Chloromethyl Ketones; Antineoplastic Agents; Apoptosis; Blotting, Western; Caspase 3; Caspases; CDC2 Protein Kinase; Cell Cycle; Cell Line, Tumor; Coloring Agents; Cyclin B; Dose-Response Relationship, Drug; Enzyme Inhibitors; Flow Cytometry; Humans; Male; Microscopy, Fluorescence; Microtubule-Associated Proteins; Microtubules; Mitosis; Neoplasm Metastasis; Neoplasm Proteins; Phosphorylation; Prostatic Neoplasms; Proto-Oncogene Proteins c-bcl-2; Rhodamines; Tetrazolium Salts; Thiazoles; Time Factors; Up-Regulation
Type
journal article