Amino Acids ; isolation & purification ; Animals ; Antineoplastic Agents, Phytogenic ; pharmacology ; Binding Sites ; Colchicine ; pharmacology ; Humans ; Microtubules ; drug effects ; physiology ; Paclitaxel ; pharmacology ; Tubulin ; chemistry ; isolation & purification ; metabolism ; Vinblastine ; pharmacology

Animals ; Antineoplastic Agents, Phytogenic ; chemistry ; pharmacology ; Cell Division ; drug effects ; Colchicine ; analogs & derivatives ; chemistry ; pharmacology ; Humans ; Molecular Structure ; Structure-Activity Relationship ; Tubulin ; drug effects ; Tumor Cells, Cultured

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

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

AIMTo search for colchicine derivatives which have high efficacy and low toxicity.

METHODSColchicine was firstly converted into thiocolchicine, and then it was hydrolyzed to get 7-(N-deacetylthiocolchicine). At last, 7-(N-deacetylthiocolchicine) was amidated to get the target compounds. The chemical structure of these new derivatives was confirmed with 1H NMR, IR, MS, and HR-MS. The cytotoxicity of the compounds was tested by MTT assay. Their in vivo antitumor activity was evaluated against mice tumor H22 and U14.

RESULTSTwelve thiocolchicine derivatives are new compounds.

CONCLUSIONIn vitro antitumor activity has showed that some of these thiocolchicines possessed cytotoxic activity superior to colchicine. However, in vivo antitumor activity indicated that these derivatives have poor efficacy in mice.

Animals ; Antineoplastic Agents, Phytogenic ; chemical synthesis ; chemistry ; pharmacology ; Cell Line, Tumor ; Cell Survival ; drug effects ; Colchicine ; analogs & derivatives ; chemical synthesis ; chemistry ; pharmacology ; Humans ; Inhibitory Concentration 50 ; Liver Neoplasms, Experimental ; pathology ; prevention & control ; Male ; Mice ; Mice, Inbred ICR ; Models, Chemical ; Molecular Structure ; Neoplasm Transplantation ; Prostatic Neoplasms ; pathology ; prevention & control ; Structure-Activity Relationship

Resveratrol has been reported to possess cancer preventive properties. In this study, we analyzed anti-tumor activity of a newly synthesized resveratrol analog, cis-3,4',5-trimethoxy-3'-hydroxystilbene (hereafter called 11b) towards breast and pancreatic cancer cell lines. 11b treatments reduced the proliferation of human pancreatic and breast cancer cells, arrested cells in the G2/M phase, and increased the percentage of cells in the subG1/G0 fraction. The 11b treatments also increased the total levels of mitotic checkpoint proteins such as BubR1, Aurora B, Cyclin B, and phosphorylated histone H3. Mechanistically, 11b blocks microtubule polymerization in vitro and it disturbed microtubule networks in both pancreatic and breast cancer cell lines. Computational modeling of the 11b-tubulin interaction indicates that the dimethoxyphenyl group of 11b can bind to the colchicine binding site of tubulin. Our studies show that the 11b treatment effects occur at lower concentrations than similar effects associated with resveratrol treatments and that microtubules may be the primary target for the observed effects of 11b. These studies suggest that 11b should be further examined as a potentially potent clinical chemotherapeutic agent for treating pancreatic and breast cancer patients.
Antineoplastic Agents/*pharmacology ; Binding Sites ; Breast Neoplasms ; Cell Cycle/drug effects ; Cell Line, Tumor ; Cell Proliferation/*drug effects ; Colchicine/chemistry/pharmacology ; Cyclin B/metabolism ; G2 Phase/drug effects ; Humans ; Microtubules/drug effects/metabolism ; Models, Molecular ; Pancreatic Neoplasms ; Protein-Serine-Threonine Kinases/metabolism ; Stilbenes/*pharmacology ; Tubulin/metabolism

Colchicine has been shown to regulate the expression of inflammatory gene, but this compound possesses much weaker anti-inflammatory activity. In this study, we synthesized a new colchicine derivative CT20126 and examined its immunomodulatory property. CT20126 was found to have immunosuppressive effects by inhibiting lymphocyte proliferation without cytotoxicity and effectively inhibit the transcriptional expression of the inflammatory genes, iNOS, TNF-alpha, and IL-1beta, in macrophages stimulated by LPS. This effect was nearly comparable to that of cyclosporine A. This compound also significantly suppressed the production of nitric oxide and Th1-related pro-inflammatory cytokines, IL-1beta, TNF-alpha, and IL-2, with minimal suppression of Th2-related anti-inflammatory cytokines IL-4 and IL-10 in the sponge matrix allograft model. Moreover, administration of CT20126 prolonged the survival of allograft skins from BALB/c mice (H-2d) to the dorsum of C57BL/6 (H-2b) mice. The in vivo immune suppressive effects of CT20126 were similar to that of cyclosporine A. These results indicate that this compound may have potential therapeutic value for transplantation rejection and other inflammatory diseases.
Animals ; Cell Line ; Colchicine/*analogs & derivatives/chemistry/*pharmacology ; Cytokines/*biosynthesis ; Female ; Gene Expression Regulation/drug effects ; Graft Survival/*drug effects ; Immunosuppression ; Interleukin-1beta/genetics/metabolism ; Lipopolysaccharides/pharmacology ; Lymphocyte Culture Test, Mixed ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Nitric Oxide/biosynthesis ; Nitric Oxide Synthase Type II/genetics/metabolism ; Skin Transplantation/*immunology ; Th1 Cells/*drug effects/immunology/metabolism ; Th2 Cells/*drug effects/immunology/metabolism ; Transplantation, Homologous ; Tumor Necrosis Factor-alpha/genetics/metabolism