Growth Inhibitory Effects Of The Nonsteroidal Anti-inflammatory Agent Celecoxib On Human Ovarian Cancer

Objectives: The study was designed to evaluate the effect of the nonsteroidal anti-inflammatory agent Celecoxib on the growth and cell apoptosis of the human ovarian cancer cell line SKOV3, to observe the growth inhibitory effect and the side effects of Celecoxib on xenografted human ovarian cancer of SKOV3 in nude mice, and to investigate the possible mechanisms involved in these effects. Methods:1. The proliferation of SKOV3 cells with Celecoxib or Aspirin were determined by MTT assay and the cell cycle were analyzed by flow cytometric assay(FCM).TUNEL method combination with FCM were used to detect cell apoptosis induced by Celecoxib or Aspirin.2. Xenografted nude mice models of human ovarian cancer were established, then randomly allocated to treatment with either 10, 25, 50mg/kg Celecoxib in distilled water or distilled water alone (control).both givenorally daily for 56 days, and all animals were sacrificed. The mice weight, tumor volume and side effects were detected.3. The protein expression and mRNA of COX-2, Caspase-3 and VEGF in SKOV3 cells with Celecoxib or Aspirin were assessed by FCM, Western blot and semiquanttative reverse transcription-polymerase chain reaction(RT-PCR)assay, respectively; and the expression of COX-2, Caspase-3, VEGF and MVD in human ovarian cancer tissue with Celecoxib were detected by imrnunocytochemistry. Results:1. After 24 hrs, Celecoxib(lxl0~5M~lxl0"3M) or Aspirin (lxl0"3M~lxl0"'M) dose dependency inhibited cell proliferation of SKOV3 cells, but time-dependent manners were not observed.2. The IC50 in this assay for Celecoxib was 5xlO"5M after 24 hr, whereas for Aspirin was 7xlO"3M. These findings indicate that Celecoxib was more effective than Aspirin.3. In contrast to the control, the apoptotic ratios(47.1% and 15.7%)of SKOV3 were increased after treatment with Celecoxib (5xlO"5M) or Aspirin(7xlO"3M) , the ratios (30.7%> 34.2%)of S phase were descend, wherease the ratios(60.9% and 56.9%) of Gi phase were increased (p<0.05). Above-mentioned apoptotic results were confirmed by TUNEL assay.4. After nude mice sacrifice, average tumor volume from control mice was 3.28±0.432 as compared with 2.457±0.223, 2.198±0.500, 2.017±0.166 from Celecoxib mice (10, 25, 50mg/kg), P<0.05, and the rate of tumor growth inhibition by Celecoxib in SKOV3 cells burden mice were 25.20%, 33.00% and 38.60%, in a dose-and time-dependent manner.5. Our physiologic data indicated a complete absence of any ulceration or bleeding. No weight loss or impairment of weight gain was observed at 10, 25, 50mg/kg/day of Celecoxib. Furthermore, significant difference was found neither in ALT, AST,TP among these four groups nor in Cr, BUN, and histopathologic examination of kidney, liver, stomach, bowel showed no abnormality, implying no untoward sides effects.6. RT-PCR showed that the expression COX-2 and VEGF mRNA were strongly down-regulated in SKOV3 cells after treatment with Celecoxib or Aspirin, whereas Caspase-3 mRNA was up-regulated. Western Blot and FCM showed that the protein expression of COX-2 and VEGF were strongly inhibited by Celecoxib or Aspirin, whereas Caspase-3 protein expression was significantly increased.7. Immunocytochemistry showed that the expression of COX-2 and VEGF in 10, 25, 50mg/kg/day of Celecoxib were lower obviously than it in the control group in Xenografted nude mice, whereas Caspase-3 expression was strongly up-regulated(P<0.05). MVD in each of 25, 50mg/kg/day of Celecoxib (10.43±2.82, 7.43±1.99)was much lower than the one of control group(16.63±3.54).Conclusion:1. Both COX-2 specific inhibitor Celecoxib and non-selective inhibitor Aspirin were able to potentially inhibit the growth and induce apoptosis in SKOV3 cells. The effect of Celecoxib was more potential than that of Aspirin.2. The growth of Xenografted nude mice models of human ovarian cancer was inhibited by Celecoxib in a dose-dependent manner, especially by50mg/kg/day of Celecoxib. The treatment is effective as well as safe within 5 Omg/kg/day of Celecoxib.3. The anti-tumor effect of Celecoxib was probably related to the down-regulation of COX-2, VEGF and CD34, and to the up-regulation of Caspase-3.