The Association Of COMT Activity And Endometrial Cancer

Objective: Endometrial cancer is a common malignancy, harm to women heath, which is known as one of three gynecological malignancies, including cervical cancer and ovarian cancer. The death rate is increasing. It is believed that exposure to estrogens, which is not opposed by progesterone, increases the risk of developing endometrial cancer. Catechol-O- methytransferase (COMT) is a methylase all over the body, which converts those metabolites of estrogens to innoxious substances and clears them from the body, then decreases the harm to the endometrium. Therefore,it is associated with the tumor. This study was designed to investigate the relationship between COMT activity and endometrial cancer, and found out new ideas of prevention and treatment.Methods: Total 25 patients in case group of The tissue samples were chosen from 25 patients, who were treated by surgery and confirmed by pathology as endometrial adenocarcinoma from 2010 March to 2010 October, in the department of Gynecology and Obstetrics in the 4th hospital of Hebei Medical University. Total 20 normal endometrium samples were chosen in the same area as control group (from patients of cervical carcinoma and uterine prolapse, without uterine fibroids, endometriosis, endometrial hyperplasia, breast cancer, and ovarian cancer et al,in clinical and pathology). The case-control study of the blood samples included 15 endometrial cancer patients and 15 healthy controls in same area place from 2010 October to 2010 January (without uterine fibroids, endometriosis, endometrial hyperplasia, breast cancer, and ovarian cancer et al, in clinical and pathology). Three milliliters of venous blood were from each subject. In vitro reaction system, with 3, 4 - dihydroxybenzoic acid (DBA) as the substrate, the samples were incubated together. Then the concentration of final product, 4 - hydroxy -3- methoxybenzoic acid (4-OH-3-MBA), was detected by RP-HPLC. COMT activity in tissue could be reflected by the process of putting the peak area into product concentration in samples in unit time(unit isμg·ml^-1·h^-1).Statistical analysis was performed using SPSS13.0 software package, and the results was indicated that x±s. Comparison of two groups was performed by the t-test and many groups by the One-Way ANOVA. With uneven variance, the comparison of two groups was performed by the non-parametric test. P<0.05 was considered significant.Results:1 The age difference was not significant between the endometrial cancer patients and healthy controls in blood and tissue samples (P=0.06, P=0.181). The distributions of the active concentration of the S-COMT(Soluble COMT,S-COMT)and MB-COMT(Membrane bound COMT,MB-COMT)were normal.2 The activity of S-COMT in tissue sample was obviously higher than MB-COMT. The active concentration of S-COMT in the case group 0.165±0.082 (μg·ml^-1·h^-1) was significantly higher than MB-COMT 0.058±0.038 (μg·ml^-1·h^-1), the difference was statistically significant (P = 0.000). The active concentration of S-COMT in the control group 0.296±0.143 (μg·ml^-1·h^-1) was significantly higher than MB-COMT0.100±0.068 (μg·ml^-1·h^-1), the difference was statistically significant (P = 0.000).3 In tissue samples, the activity of S-COMT in case group(0.165±0.082) was obviously lower than control group(0.296±0.143), the difference was statistically significant (P=0.001). But the activity of MB-COMT in two groups were not significantly different (P=0.051).4 In blood samples, the activity of S-COMT were not significantly different (P=0.104) between the case and control groups. The S-COMT activity in case and control groups(0.296±0.143,0.165±0.082) were obviously higher than that in blood samples respectively(0.024±0.006,0.019±0.006), the difference was statistically sigficant (P=0.000,P=0.000).5 In case group, COMT activity in poorly differentiated endometrial cancer (GradeⅢ) was obviously lower than that in moderately and well differentiated endometrial cancer (GradeⅠ,Ⅰ) (P=0.013). But the association between COMT activity and myometrial invasion was not confirmed.Conclusion:1 S-COMT is the main activity style in endometrium. The activity of S-COMT in endometrial cancer was obviously lower than normal endometrium, indicating that the decrease of the COMT activity may play an important role in the occurrence of endometrial cancer.2 S-COMT activity in peripheral blood was much lower than endometrium tissue, but the relation between the change of activity and endometrial cancer is not sure.3 There was no obvious association between S-COMT activity and myometrial invasion of endometrial cancer. It was much lower in poorly differentiated endometrial cancer, than in moderately and well differentiated endometrial cancer, suggesting that S-COMT activity may be correlated with cell differention of endometrial cancer.4 The method to increase the COMT activity in endometrium may be a way to prevent or threat endometrial cancer.