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

A series of noscapine analogues have been synthesized via 13-step reaction starting from 2-hydroxy-3-methoxybenzaldehyde. Anti-tumor activities of these compounds were evaluated against HL-60 cell lines in vitro by the standard MTT assay. It was found that most of these derivatives showed appreciable inhibitory activity against HL-60 and tubulin polymerization. The results also indicated that the potency of compound 31 is about three times more than that ofnoscapine against HL-60 cell line and tubulin polymerization. Moreover, it induced a massive accumulation of cells in G2/M phase. These results showed noscapine and its derivatives were worth to be intensively studied further.
Antineoplastic Agents ; chemical synthesis ; pharmacology ; Cell Cycle ; drug effects ; HL-60 Cells ; Humans ; Noscapine ; analogs & derivatives ; chemical synthesis ; pharmacology ; Polymerization ; drug effects ; Tubulin ; metabolism ; Tubulin Modulators ; chemical synthesis ; 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

OBJECTIVETo investigate the differentiation induction effect of 2-methoxyestradiol (2ME2), an estrogen derivative on myeloma cell line CZ-1.

METHODSThe changes of CZ-1 cells in morphology, expression of surface CD49e and quantity of light chain secretion in the supernatant were observed when treated with 0.1 approximately 0.5 micromol/L 2ME2 for 48 h.

RESULTS2ME2 could induce differentiation of CZ-1 cells. The cells appeared decreased in size of nucleus, increased in cytoplasma, decreased in the ratio of nucleus to plasma, decreased in number or disappearance of nucleolus, and thickness and pyknosis of chromatin. The expression of CD49e was increased from (12.20 +/- 1.57)% to (24.80 +/- 1.26)% (P < 0.05). Light chain secretion in the supernatant was increased from (35.97 +/- 2.60) microg/ml to (79.67 +/- 1.88) microg/ml (P < 0.05).

CONCLUSIONLow concentrations of 2ME2 could induce differentiation of myeloma cell line CZ-1.

Cell Differentiation ; drug effects ; Cell Line, Tumor ; Dose-Response Relationship, Drug ; Estradiol ; analogs & derivatives ; pharmacology ; Flow Cytometry ; Humans ; Integrin alpha5 ; analysis ; Multiple Myeloma ; metabolism ; pathology ; Tubulin Modulators ; pharmacology

OBJECTIVETo investigate the effect of trichostatin A (TSA)/paclitaxel on the growth and apoptosis in human lung adenocarcinoma cell line A549 cells.

METHODSHuman lung adenocarcinoma A549 cells were cultured in DMEM in the presence of paclitaxel and the histone deacetylase inhibitor trichostatin A, and the growth curve was obtained by trypan-blue exclusion assay and cell count. Apoptosis was assessed using Hoechst 33258 staining and flow cytometry, and cell cycle was detected by flow cytometry analysis. The proteins of PARP, caspase-3, survivin and tubulin acetylation were detected by Western blotting.

RESULTSSignificant growth reduction was observed in the A549 cells following treatment with paclitaxel or the histone deacetylase inhibitor TSA. The combined treatment with TSA/paclitaxel caused the highest inhibition of cell growth. The apoptosis rate of A549 cells treated with TSA or paclitaxel for 24 hours was (17.6 ± 1.8)% and (39.2 ± 3.7)%, respectively, but a significantly higher apoptosis rate was (64.2 ± 4.2)% was induced by combined treatment with TSA and paclitaxel. In contrast with the control group, the cell cycle was markedly arrested at G2/M phase in the TSA and paclitaxel group (P < 0.05). The Western blot analysis demonstrated that treatment with TSA/paclitaxel led to a synergistic increase of acetylated tubulin, PARP and caspase-3, and reduced the expression of survivin.

CONCLUSIONTSA or paclitaxel alone can inhibit the cell growth and induce apoptosis, and the combination of TSA and paclitaxel exerts a synergistic effect on the growth and apoptosis in lung adenocarcinoma cells.

Acetylation ; Adenocarcinoma ; metabolism ; pathology ; Antineoplastic Agents, Phytogenic ; pharmacology ; Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Cell Cycle ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Drug Synergism ; Histone Deacetylase Inhibitors ; pharmacology ; Humans ; Hydroxamic Acids ; pharmacology ; Inhibitor of Apoptosis Proteins ; metabolism ; Lung Neoplasms ; metabolism ; pathology ; Paclitaxel ; pharmacology ; Poly(ADP-ribose) Polymerases ; metabolism ; Tubulin ; metabolism ; Tubulin Modulators ; 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

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

In this study, the antitumor activities of VEGF shRNA and tubulin inhibitors on human prostate cancer DU145 cells was investigated, and shRNA transient expression plasmid pCSH1-VEGF targeting VEGF mRNA was constructed. The silence efficiency of pCSH1-VEGF was detected by RT-PCR assay, Western blotting, and Matrigel invasion assay. The sensitivity change of DU145 cells to Taxol and vincristine (VCR) was measured by MTT assay. To detect the effects of pCSH1-VEGF and Taxol in vivo, nude mice model of DU145 xenograft tumor was established by subcutaneous inoculation. The results showed that transcription and expression of VEGF were knocked by pCSH1-VEGF in DU145 cells. Matrigel invasion assay results showed that pCSH1-VEGF significantly reduced the migration of DU145 cells with inhibitory rate of 56.1%. Furthermore, pCSH1-VEGF enhanced the sensitivity of DU145 cells to Taxol and vincristine, and the values of IC50 decreased by 77.3% and 92.6%, respectively. In vivo experiment showed that Taxol, pCSH1-VEGF, combination of pCSH1-VEGF and Taxol inhibited tumor growth by the rates of 48.8%, 56.2% and 81.8%, respectively. The coefficient of drug interaction (CDI) of pCSH1-VEGF and Taxol was 0.82. The data suggested that VEGF shRNA could significantly enhance the sensitivity of human prostate cancer to tubulin inhibitors.
Animals ; Antineoplastic Agents, Phytogenic ; pharmacology ; Cell Line, Tumor ; Cell Movement ; drug effects ; Cell Proliferation ; drug effects ; Genetic Vectors ; Humans ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Neoplasm Transplantation ; Paclitaxel ; pharmacology ; Plasmids ; Prostatic Neoplasms ; metabolism ; pathology ; RNA Interference ; RNA, Small Interfering ; genetics ; Transfection ; Tubulin Modulators ; pharmacology ; Tumor Burden ; drug effects ; Vascular Endothelial Growth Factor A ; genetics ; metabolism ; Vincristine ; pharmacology