OBJECTIVETo investigate the possible mechanisms of nobiletin for anticancer by studying the inhibition effects of nobiletin on tubulin polymerization.

METHODIn vitro nobiletin was added into the tubulin polymerization-depolymerization system and the absorption values were recorded at 350 nm under 37 degrees C.

RESULTAs compared with controls, the absorption values in reaction system decreased significantly in nobiletin treatment groups. When nobiletin final concentrations in reaction system were 5.0, 7.5, 10.0 and 12.5 micromol x L(-1), the maximum absorption values were 0 130, 0.109, 0.086 and 0.071 with 16.7%, 30.1%, 44.9% and 54.5% of inhibition rate, respectively. The results suggested that nobiletin could inhibit tubulin polymerization.

CONCLUSIONThe inhibition effect of nobiletin on tubulin polymerization is the possible mechanism for anticancer.

Animals ; Flavones ; pharmacology ; Protein Binding ; drug effects ; Swine ; Tubulin ; chemistry ; metabolism ; Tubulin Modulators ; pharmacology

Microtubule is one of the key components of the cytoskeleton and plays an important role in the maintenance of cell shape and the process of signal transduction and mitosis. Due to the extreme importance of microtubule in the process of mitosis, tubulin becomes one of the most important targets for development of new anticancer drugs and tubulin inhibitors are used for the treatment of cancer nowadays. These inhibitors have antitumor activity by inhibiting or promoting the assembly of tubulin to microtubules and interfering the process of cell mitosis. This review summarized the research progress of the tubulin inhibitors, especially the introduction of the tubulin inhibitors of pharmacological activities and the progress of clinical research. Also, the development trend of these inhibitors is discussed.
Antineoplastic Agents ; chemical synthesis ; chemistry ; pharmacology ; Humans ; Microtubules ; drug effects ; metabolism ; Mitosis ; drug effects ; Molecular Structure ; Neoplasms ; drug therapy ; Stilbenes ; chemical synthesis ; chemistry ; pharmacology ; Structure-Activity Relationship ; Tubulin ; metabolism ; Tubulin Modulators ; chemical synthesis ; chemistry ; pharmacology

Podophyllotoxone (1) was isolated from the roots of Dysosma versipellis. The structure was determined by spectroscopic analysis in combination with single-crystal X-ray analysis. The absolute configuration of compound 1 was assigned based on the Flack parameter. It showed significant inhibitory activities against human prostate cancer cells PC3 and DU145 with IC50 values being 14.7 and 20.6 μmol·L(-1), respectively. It also arrested the cells at G2/M phase. Tubulin polymerization assay showed that it inhibited the tubulin polymerization in a dose-dependent manner, and molecular docking analysis revealed a different binding mode with tubulin as compared with those known tubulin inhibitors.
Antineoplastic Agents ; chemistry ; pharmacology ; Berberidaceae ; chemistry ; Cell Line, Tumor ; Dose-Response Relationship, Drug ; G2 Phase ; drug effects ; Humans ; Hydrogen Bonding ; drug effects ; Male ; Molecular Conformation ; Molecular Docking Simulation ; Phytotherapy ; Plant Extracts ; chemistry ; pharmacology ; Plant Roots ; chemistry ; Podophyllotoxin ; chemistry ; pharmacology ; Polymerization ; Prostatic Neoplasms ; drug therapy ; Tubulin ; drug effects ; Tubulin Modulators ; pharmacology

Vascular disrupting agents (VDAs) have presented a new kind of anti-cancer drug in recent years. VDAs take advantage of the weakness of established tumor endothelial cells and their supporting structures. In contrast to anti-angiogenic therapy, which inhibits the outgrowth of new blood vessels, vascular targeting treatments selectively attack the existing tumor vasculature. Here we summarized the anti-tumor activities, mechanisms and clinical applications of small molecule VDAs.
Angiogenesis Inhibitors ; chemistry ; pharmacology ; therapeutic use ; Animals ; Antineoplastic Agents ; chemistry ; pharmacology ; therapeutic use ; Bibenzyls ; chemistry ; pharmacology ; therapeutic use ; Diphosphates ; chemistry ; pharmacology ; therapeutic use ; Endothelial Cells ; drug effects ; Humans ; Molecular Structure ; Neoplasms ; drug therapy ; pathology ; Neovascularization, Pathologic ; Oligopeptides ; chemistry ; pharmacology ; therapeutic use ; Organophosphorus Compounds ; chemistry ; pharmacology ; therapeutic use ; Serine ; analogs & derivatives ; chemistry ; pharmacology ; therapeutic use ; Stilbenes ; chemistry ; pharmacology ; therapeutic use ; Tubulin Modulators ; chemistry ; pharmacology ; therapeutic use ; Xanthones ; chemistry ; pharmacology ; therapeutic use

New colchicine analogs have been synthesized with the aim of developing stronger potential anticancer activities. Among the analogs, CT20126 has been previously reported to show immunosuppressive activities. Here, we report that CT20126 also shows potential anticancer effects via an unusual mechanism: the modulation of microtubule integrity and cell cycle arrest at the G2/M phase before apoptosis. When we treated COS-7 cells with CT20126 (5 muM), the normal thread-like microtubules were disrupted into tubulin dimers within 10 min and thereafter repolymerized into short, thick filaments. In contrast, cells treated with the same concentration of colchicine exhibited microtubule depolymerization after 20 min and never underwent repolymerization. Furthermore, optical density (OD) analysis (350 nm) with purified tubulin showed that CT20126 had a higher repolymerizing activity than that of Taxol, a potent microtubule-polymerizing agent. These results suggest that the effects of CT20126 on microtubule integrity differ from those of colchicine: the analog first destabilizes microtubules and then stabilizes the disrupted tubulins into short, thick polymers. Furthermore, CT20126 induced a greater level of apoptotic activity in Jurkat T cells than colchicine (assessed by G2/M arrest, caspase-3 activation and cell sorting). At 20 nM, CT20126 induced 47% apoptosis among Jurkat T cells, whereas colchicine induced only 33% apoptosis. Our results suggest that the colchicine analog CT20126 can potently induce apoptosis by disrupting microtubule integrity in a manner that differs from that of colchicine or Taxol.
Acetylation/drug effects ; Animals ; Apoptosis/*drug effects ; COS Cells ; Caspase 3/metabolism ; Cattle ; Cell Division/drug effects ; Cercopithecus aethiops ; Colchicine/*analogs & derivatives/chemistry/pharmacology ; Enzyme Activation/drug effects ; G2 Phase/drug effects ; Humans ; Jurkat Cells ; Microtubules/*metabolism ; Poly(ADP-ribose) Polymerases/metabolism ; Tubulin/metabolism ; Tubulin Modulators/chemistry/*pharmacology

Pyrimidine derivatives have been the subject of much attention in pesticide and medicine fields owing to their unique biological properties. Particularly, a large number of these compounds have recently been reported to show substantial antitumor activities, and some of them have been investigated in clinical trials. Although these structurally novel compounds have a common chemical moiety of a pyrimidine ring, there are a variety of mechanisms of their antitumor action, such as, inhibition of cyclin-dependent-kinases, inhibition of protein tyrosine kinase, inhibition of carbonic anhydrases, inhibition of dihydrofolate reductase and disruption of microtubule assembly. In this paper, we described the latest advances in the research of such pyrimidine derivatives as antitumor drug according to their action on targets.
Animals ; Antineoplastic Agents ; chemistry ; pharmacology ; therapeutic use ; Carbonic Anhydrase Inhibitors ; pharmacology ; Cell Proliferation ; drug effects ; Cyclin-Dependent Kinases ; antagonists & inhibitors ; Folic Acid Antagonists ; pharmacology ; Humans ; Neoplasms ; drug therapy ; pathology ; Protein-Tyrosine Kinases ; antagonists & inhibitors ; Pyrimidines ; chemistry ; pharmacology ; therapeutic use ; Tetrahydrofolate Dehydrogenase ; pharmacology ; Tubulin Modulators ; pharmacology ; therapeutic use

The massive reorganization of microtubule network involves in transcriptional regulation of several genes by controlling transcriptional factor, nuclear factor-kappa B (NF-kappaB) activity. The exact molecular mechanism by which microtubule rearrangement leads to NF-kappaB activation largely remains to be identified. However microtubule disrupting agents may possibly act in synergy or antagonism against apoptotic cell death in response to conventional chemotherapy targeting DNA damage such as adriamycin or comptothecin in cancer cells. Interestingly pretreatment of microtubule disrupting agents (colchicine, vinblastine and nocodazole) was observed to lead to paradoxical suppression of DNA damage-induced NF-kappaB binding activity, even though these could enhance NF-kappaB signaling in the absence of other stimuli. Moreover this suppressed NF-kappaB binding activity subsequently resulted in synergic apoptotic response, as evident by the combination with Adr and low doses of microtubule disrupting agents was able to potentiate the cytotoxic action through caspase-dependent pathway. Taken together, these results suggested that inhibition of microtubule network chemosensitizes the cancer cells to die by apoptosis through suppressing NF-kappaB DNA binding activity. Therefore, our study provided a possible anti-cancer mechanism of microtubule disrupting agent to overcome resistance against to chemotherapy such as DNA damaging agent.
Animals ; Antibiotics, Antineoplastic/therapeutic use ; *Apoptosis ; Caspases/metabolism ; Cell Line ; Colchicine/pharmacology ; DNA/metabolism ; *DNA Damage ; Doxorubicin/therapeutic use ; Humans ; Mice ; Microtubules/chemistry/*drug effects/metabolism ; NF-kappa B/antagonists & inhibitors/*metabolism ; Neoplasms/drug therapy ; Nocodazole/pharmacology ; Protein Binding ; Signal Transduction ; Tubulin Modulators/*pharmacology ; Vinblastine/pharmacology