Effects of the Specific COX-2 Inhibitor, Celecoxib, on Paclitaxel-Induced Apoptosis in SK-OV-3 Epithelial Ovarian Cancer Cell Line / 대한산부인과학회지

OBJECTIVE: In vitro studies have revealed that treatment of various human cancer cell lines with specific cyclooxygenase 2 (COX-2) inhibitors induces apoptotic cell death. The goal of this article is to investigate the benefits of combining COX-2 inhibitors with existing treatment modalities in the management of ovarian cancer. METHODS: In this study we sought to determine the effects of combining paclitaxel and the COX-2 inhibitor celecoxib on apoptosis of epithelial ovarian cancer (EOC) cells. SK-OV-3 cells were exposed to increasing concentrations of paclitaxel (10(-7) M, 10(-6) M and 10(-5) M) and celecoxib (10(-8) M, 10(-7) M, 10(-6) M, 10(-5) M and 10(-4) M) as well as a combination of both drugs. The activity of apoptosis was evaluated by the morphologic examination and the MTT assay. The pattern of apoptosis was also assessed by the caspase-3 activity and the fraction of cleaved PARP (poly ADP-ribose polymerase) protein. RESULTS: Single application of both drugs could significantly increase the rate of apoptosis after 24 hours of continuous exposure. But concomitant treatment of SK-OV-3 EOC cell line with paclitaxel and celecoxib resulted in marked impairment of paclitaxel-induced apoptosis. The pattern of apoptosis induced by paclitaxel on SK-OV-3 EOC cell line was caspase-3 independent. CONCLUSION: Combining COX-2 inhibitors and paclitaxel does not have an additive or synergistic tumoricidal effect. On the contrary, celecoxib treatment markedly inhibited the apoptotic effects of paclitaxel in SK-OV-3 EOC cell line.

In Vitro Responses of SK-OV-3 Ovarian Cancer Cell Lines to Tamoxifen and Celecoxib / 대한산부인과학회지

OBJECTIVE: There are some evidences that some epithelial ovarian cancer cells respond to hormonal therapy. And in vitro studies have revealed that treatment of various human cancer cell lines with selective cyclooxygenase 2 (COX-2) inhibitors induces apoptotic cell death. The goal of this article is to evaluate the effects of tamoxifen and celecoxib, a selective COX-2 inhibitor, on the ovarian cancer cells and the benefits of combining these agents in the management of ovarian cancer. METHODS: SK-OV-3 epithelial ovarian cancer cells were exposed to increasing concentration of tamoxifen (10(-8) M, 10(-7) M, 10(-6) M, 10(-5) M and 10(-4) M) and celecoxib (10(-8) M, 10(-7) M, 10(-6) M, 10(-5) M and 10(-4) M) as well as a combination of both drugs. The activity of apoptosis was evaluated by the morphologic examination and the MTT assay. The pattern of apoptosis was also assessed by the caspase-3 activity and the fraction of cleaved PARP (poly ADP-ribose polymerase) protein. RESULTS: Single application of both drugs could significantly increase the rate of apoptosis after 24 h of continuous exposure. Concomitant treatment of SK-OV-3 cells with tamoxifen and celecoxib induced significant increase in apoptosis, comparing with single drug exposure. The pattern of apoptosis induced by these agents on SK-OV-3 cells seemed to be caspase-3 dependent. CONCLUSION: Our data suggest that combining tamoxifen with selective COX-2 inhibitor seems to have at least an additive tumoricidal effect. A more definitive role for this combination therapy in clinical settings in ovarian cancer will need to be defined through the conduct of clinical trials.

Apo-1/Fas (CD95) Gene Polymorphism in Korean Hepatocellular Carcinoma Patients

It is well known that different expression of Apo-1/Fas (CD95) plays important roles in various tumors and hepatocellular carcinoma (HCC) pathogenesis. Apo-1/Fas mediated apoptosis is one of the important pathways of apoptosis and is known to mediate apoptotic cell death by fas ligand (FasL). To examine the possible relationship between Apo-1/Fas gene polymorphism and HCC susceptibility, MvaI restriction fragment length polymorphism (RFLP) of Apo-1/Fas gene was examined in 94 Korean HCC patients and 240 control subjects. No statistically significant difference in the genotypic distribution and allelic frequencies was found between the control and the HCC. It is, therefore, concluded that Apo-1/Fas gene polymorphism is not associated with HCC susceptibility. Further studies are needed in order to clarify the relationships between genotypes of Apo-1/Fas gene and HCC pathogenesis.

No Association between Catalase Gene Polymorphism and Gastric Carcinoma and Hepatocellular Carcinoma in Koreans / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Oxidative stress has been implicated in the pathogenesis of various diseases. Catalase is one of the main defense mechanisms against oxidative stress. To examine the possible relationship between oxidative stress, and gastric and hepatocellular carcinomas, HinfI restriction length polymorphism (RFLP) in the human catalase gene was assessed. MATERIALS AND METHODS: The genotype and allele frequencies in the promoter region of the catalase gene were studied by PCR-RFLP in 108 Korean controls, 80 Korean gastric carcinoma (GC) and 106 Korean hepatocellular carcinoma (HCC) patients. RESULTS: No statistically significant differences were found in the genotypic distribution and allelic frequencies between the controls and both types of carcinoma patient. CONCLUSION: To address the possible contribution of oxidative stresses to the pathogenesis of gastric and hepatocellular carcinomas, the associations between the catalase gene polymorphism and GC and HCC susceptibilities were studied. As a result, the catalase gene polymorphism was found not to be determinant of GC and HCC susceptibilities. Further studies are required on various other oxidative stress related genes to elucidate the mechanisms of GC and HCC.