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OBJECTIVE: To study the effect of selective COX (cyclooxygenase)-2 inhibitor valdecoxib on the growth of human breast cancer MCF-7/ADR(MCF-7/adriamycin) cells. METHODS: MTT assay was used to observe the effect of drugs on the growth of cells. Flow cytometry and Hoechst 33258 dye were used to detect apoptosis of MCF-7/ADR cells. The levels of GSH and GSSG were detected by kit; Laser confocal microscopy was used to detect the levels of ROS. RESULTS: Valdecoxib significantly inhibited the growth of human breast cancer MCF-7/ADR cells and induced apoptosis of the cells. Caspase 3 inhibitor Ac-DEVD-CHO and caspase inhibitor Z-VAD-FMK antagonized the inhibitory effect of valdecoxib on MCF-7/ADR cell growth. Valdecoxib significantly decreased GSH/GSSG ratio and increased the level of ROS, and antioxidant V-acetylcysteine antagonized the inhibitory effect of valdecoxib on MCF-7/ADR cell growth. CONCLUSION: The apoptosis of human breast cancer MCF-7/ADR cells induced by valdecoxib is associated with increase of ROS.
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OBJECTIVE: To study the effect of valdecoxib and pirarubicina combination on cell cycle and apoptosis of human lung cancer A549 cell line in vitro. METHODS: MTT assay was used to analyze the effect of valdecoxib and pirarubicina on the growth of human lung cancer A549 cell line. The median-effect principle was applied to determine the combination effect of valdecoxib and pirarubicina. Flow cytometry (FCM) was used to observe the cell cycle and apoptosis. The expressions of Bcl-2, Bax, and Caspase-3 were detected by western blotting. RESULTS: The inhibition ratio of A549 cell in valdecoxib and pirarubicina combination group was increased compared with their respective application, and CI<1. In valdecoxib and pirarubicina combination group, the apoptosis rate and the expression of Bax and Caspase-3 was increased, and the expression of Bcl-2 was decresed. CONCLUSION: Valdecoxib and pirarubicina combination has synergistic effect, which is partly due to the increase of the apoptosis rate.
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An oral controlled onset dosage form intended to approximate the chronobiology of rheumatoid arthritis was proposed for colonic targeting. The multiparticulate system comprising of non-pareil seeds coated with Eudragit S100 was designed for chronotherapeutic delivery of valdecoxib. The drug was coated onto non-pareil seeds by powder layering technique using the conventional coating pan. Different coat weights of non-aqueous dispersions were applied onto the drug-coated pellets using spray coating technique. In vitro dissolution tests of the coated pellets were performed in different pH media for a period of 11 hours. The in-vitro dissolution tests showed that the release of valdecoxib from the coated pellets depended on the pH of the dissolution fluid and the coat weights applied. All the formulations exhibited no release of drug in the pH 1.2 and pH 4 buffers; drug release took place in phosphate buffer of pH 7.4. Further intactness of the drug in the formulation and the uniformity of the polymer coating were checked by the infrared study and scanning electron microscopy. Stability studies inferred that the drug undergoes no considerable degradation pattern at room temperature and 40oC even after three weeks. All the above results show that the formulation could be highly advantageous in the chronotherapy of rheumatoid arthritis with appreciable drug release and physiochemical properties.
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BACKGROUND: Valdecoxib is a selective cyclooxygenase-2 (COX-2) inhibitor. It is effective in the treatment of rheumatoid arthritis, osteoarthritis, primary dysmenorrhea, and postoperative pain. Two kinds of sodium currents, tetrodotoxin-sensitive (TTX-S) and tetrodotoxin-resistant (TTX-R), are expressed in the dorsal root ganglia (DRG). Both sodium currents are implicated in the formation of normal and abnormal pain. METHODS: The effects of valdecoxib on sodium currents in rat DRG neurons were investigated using the whole-cell variation of the patch-clamp technique. RESULTS: Valdecoxib suppressed two types of sodium currents in a dose-dependent manner, without altering the activation and inactivation kinetics of either current type. It shifted the activation voltage toward a depolarizing direction and the steady-state inactivation voltage toward a hyperpolarizing direction, and suppressed resting channels to similar extents in both types of sodium currents. Valdecoxib slowed the recovery of both sodium currents from inactivation, and suppressed them in a frequency-dependent manner. CONCLUSIONS: The results suggest that valdecoxib may produce analgesic effects through the inhibition of sodium currents in sensory neurons as well as COX-2.
Subject(s)
Animals , Female , Rats , Analgesia , Arthritis, Rheumatoid , Cyclooxygenase 2 , Diagnosis-Related Groups , Dysmenorrhea , Ganglia, Spinal , Kinetics , Neurons , Osteoarthritis , Pain, Postoperative , Patch-Clamp Techniques , Sensory Receptor Cells , Sodium Channels , Sodium , TetrodotoxinABSTRACT
Objective To study the inhibitory effect of valdecoxib on Lewis tumor and the potential relationship with cyclooxygenase-2(COX-2).Methods HE staining was used to observe lymphocyte infiltration in tumor tissue and the cell structure of the stomach and colon.Western blotting was used to detect the expression of COX-2 in tumor tissue.PGE_2 ELISA kit was used to detect the content of PGE_2 in tumor tissue.Results ① Valdecoxib inhibited the growth of the tumor,and the survival rate was increased.②There was lymphocyte infiltration in treatment group and the content of PGE_2 was decreased.③Valdecoxib did not affect cell structure of stomach and colon,bleeding and clotting time.Conclusion Valdecoxib inhibits the growth of the Lewis tumor and enhances the survival rate.The effect of valdecoxib is related to the inhibition of COX-2.
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Aim To evaluate the effect and the mechanism of valdecoxib on Lewis cancer. Methods Western blot was used to detect the expression of VEGF, MMP-2, Bax, Bcl-2 and Caspase-3 in tumor tissue. Flow cytometry was used to observe the effect of valdecoxib on proliferation, apoptosis and the cell cycle distribution. MTT assay was used to observe the lymphocyte transformation rate. Results ① Valdecoxib inhibited the growth of the tumor and increased the survival rate. ② 10~40 mg?kg -1?d -1 Valdecoxib increased the apoptosis rate from 19.1% in control group to 23.1%~29.1%, and did not affect the distribution of cell cycle. ③ The expression level of Bcl-2 was decreased and expression levels of Bax, COX-2, MMP-2, Caspase-3 and VEGF were not affected. ④ Valdecoxib did not affect the weight, the lymphocyte transformation rate, spleen index, and thyrus index of the mice. Conclusion The inhibitory effect of valdecoxib on Lewis tumor is associated with apoptosis.
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Aim To investigate the effect and mechanism of valdecoxib on the apoptosis of human esophageal cancer cells.Methods Flow cytometry was used to observe the effect of valdecoxib on apoptosis and the cell cycle distribution of Eca109 cells.Transmission electron microscope was further used to detect the cell apoptosis.The content of LDH was examined using LDH kit.The expressions of p-p38MAPK,Fas and FasL protein were detected using flow cytometry.Results Valdecoxib of 25～400 ?mol?L~(-1) significantly induced the apoptosis of Eca109 cell line,and the rate of apoptosis was increased from(2.95?0.83)% to(48.46?0.73)%,50～400 ?mol?L~(-1) valdecoxib also decreased the proliferation index and the proportion of cells in the S phase,increased the proportion of cells in the G_0/G_1 phase,but had no effect on the proportion of cells in the G_2/M phase.Compared with those in Eca109 cells cultured in the medium with solvent,the expression of p-p38MAPK,Fas and FasL was higher in the Eca109 cells exposed to valdecoxib in a dose-dependent manner in 72 h.Conclusion Valdecoxib can induce apoptosis of Eca109 cell line partly by up-regulating the expression of p-p38MAPK/Fas/FasL.
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AIM To study the effect and mechanism of valdecoxib, a selective COX 2 inhibitor, on human gastric cancer BGC 823 cells. METHODS MTT assay and flow cytometry were used to observe the effect of valdecoxib on proliferation, apoptosis and the cell cycle distribution of BGC 823 cells. Laser confocal microscopy, transmission electron microscope and DNA fragmentation assay were further used to detect the apoptosis. The content of LDH was examined using LDH kit. RESULTS Valdecoxib in 25～400 ?mol?L -1 significantly inhibited the proliferation of BGC 823 cell in a time and dose dependent fashion, the inhibition rate of proliferation was 24 0%～92 0% after 72 h, and the rate of apoptosis was increased from (2 6?0 7)% to (7 6?1 5) %～(16 5?1 5)%. 100～400 ?mol?L -1 valdecoxib also decreased the proliferation index and the proportion of cells in the S phase, increased the proportion of cells in the G 0/G 1 phase, but had no effect on the proportion of cell in the G 2/M phase. CONCLUSION Valdecoxib inhibits human gastric cancer BGC 823 cells growth by inducing apoptosis and cell cycle arrest. The growth inhibitory effect of 400 ?mol?L -1 valdecoxib is also associated with cell necrosis.
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Aim To investigate the effects and possible mechanism of valdecoxib on apoptosis of cancer in nude mice.Methods The tumor model was established by inoculating 2?106 cell both in the left and right armpit respectively.The mice were divided randomly into control group and valdecoxib group(20 mg?kg-1?day-1).Valdecoxib was dissolved in carboxymethylcellulose sodium and administered from the second day after inoculation.The mice were killed after 4 weeks.The volumn and inhibitory rate were calculated according to the length and width of xenograft tumor.H.E staining was used to observe the cell structure of the stomach and colon.The apoptotic rate was detected by FCM.The expression of COX-2,c-jun and c-fos protein was detected by FCM and immunohistochemical staining.Total RNA was extracted with Trizol method and the expression of COX-2 mRNA was detected by RT-PCR.Results(1) The body weight of nude mice was higher in valdecoxib treated group in a time-dependent manner.(2) Valdecoxib inhibited the growth of tumor.The weight of tumor was decreased from(1.43?0.52)g in control group to(0.93?0.53)g in valdecoxib treated group.The ratio of inhibition on the growth of tumor was 45.80%.(3) Valdecoxib increased the apoptosis rate from(14.15?0.48)% in control group to(29.80?6.35)% in treated group.(4) The expression of COX-2 mRNA and protein decreased in treated group compared with that in control group.FCM and immunohistochemical staining showed that the expressions of c-jun and c-fos were increased in valdecoxib treated group.There was statistical significance compared with control group.(5) There was significantly negative correlation between the ratio of apoptosis and the expression of COX-2(r=-0.726,P=0.008);there was significantly positive correlation between the ratio of apoptosis and the expressions of c-jun and c-fos protein respectively(r=0.603,0.813;P=0.038,0.001);(6) Valdecoxib did not affect cell structure of stomach and colon.Conclusions valdecoxib inhibits the growth of the xenograft tumor in nude mice and induces the apoptosis.Decreasing expression of COX-2 and up-regulating the expressions of c-jun and c-fos may be one of the mechanisms for the apoptosis.
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Aim To investigate the regulatory effect of p38MAPK signal pathway on the apoptosis of human esophageal cancer cells induced by valdecoxib.Methods The tumor cells were inoculated in the dose of 1?107?L-1.After 6 h,the cells were divided into control group,solution group,400,200,100,50,25 ?mol?L-1 valdecoxib group and various concentration valdecoxib+SB203580 group,cultured for 72 h.FCM and DNA Ladder were used to detect the apoptosis of Eca109 cells.p38 mRNA expression was detected by RT-PCR.The expression of p-p38MAPK protein was detected by immunohistochemical staining and FCM.Results ① Valdecoxib could increased the apoptosis rate of Eca109 cell in concentration-dependent fashion.Apoptosis rate was increased to 48.46% in 400 ?mol?L-1 valdecoxib group at the incubation time of 72 h.DNA ladder was the most recognized marker of apoptosis,and there was obvious DNA ladder in valdecoxib treated group,especially in 400 ?mol?L-1 group.② Valdecoxib could increase the expression of p38MAPK,while SB203580 could inhibit the over-expression induced by valdecoxib,at the same time,the apoptosis rate was been decreased.③ The expression of p38MAPK protein was positively correlated with the apoptotic rate(r=0.822,P=0.000).Conclusions Valdecoxib could activate p38MAPK pathway,thus induce the apoptosis of Eca109 cells,which may be one of the mechanisms for the inhibition of cell growth by valdecoxib.
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Objective To evaluate the inhibitory effect of valdecoxib on the growth of the cancer cell lines and involvement of COX-2 in this inhibition. Methods Western blotting and immunocytochemistry were used to detect the expression of COX-2. MTT assay was used to determine inhibitory effect of the drugs on the cell growth. The content of PGE_ 2 in cell medium was determined with PGE_ 2 ELISA kit. Results ①Clone 26 cells expressed high levels of COX-2, whereas BGC-823,HGC-27 and SK-OV-3 cell had no COX-2 expression. ②Valdecoxib inhibited the growth of BGC-823, HGC-27, SK-OV-3 and clone 26 cells, with a IC_ 50 of 110.7, 99.2, 113.3, 117.6 ?mol/L, respectively. ③The inhibitory effect of these drugs on BGC-823 and clone 26 cell was in the descending order of valdecoxib, SC-560 and indomethacin. ④PGE_ 2 did not antagonize the effect of valdecoxib, SC-560 and indomethacin on BGC-823 and clone 26 cells. ⑤The inhibitory effect of valdecoxib and indomethacin on the growth of clone 26 cells was not compatible with that on PGE_ 2 . Conclusion The inhibitory effect of valdecoxib on cell growth is not related to its effect on COX-2.