Objective: To demonstrate O6- methylguanine- DNA methyltransferase (MGMT) and glutathione S- transferase (GST) activities by analyzing the sera separately obtained from patients with malignant ovarian tumors, benign o...Objective: To demonstrate O6- methylguanine- DNA methyltransferase (MGMT) and glutathione S- transferase (GST) activities by analyzing the sera separately obtained from patients with malignant ovarian tumors, benign ovarian tumors, and healthy individuals. Study Design: Fourty- nine patients with ovarian cancer, nine patients with benign tumors, and 22 healthy women were included in this study. Blood samples were obtained from all the subjects in the malignant- tumor, benign- tumor, and control groups. Patients with malignant tumors underwent second and third phlebotomies one week following the surgery and after the chemotherapy regimen, respectively. MGMT, GST, and protein levels were measured for each serum sample. GST activity of the samples was measured by the method of Habig et al. using l- chloro- 2- 4 dinitrobenzene (CDNB) as substrate. MGMT activity was measured by the transfer of radio labelled methyl groups from a prepared MG- DNA substrate to the enzyme fraction of serum. Protein concentration was measured by biuret method. Results: Our work demonstrated that untreated patients with malignant ovarian tumors revealed significantly greater MGMT and GST activities in their sera than did both healthy individuals and patients with benign ovarian tumors, while no significant difference was found between the healthy group and the patients with benign ovarian tumors with respect to their sera MGMT and GST activities. GST activity following chemotherapy was significantly lower than the postoperative values preceding chemotherapy. A relationship between sera MGMT and GST activities, tumor histology and pathology was not found in this study. Conclusion: Our work suggests the fact that detection of sera MGMT and GST activities is important in diagnostic and therapeutic approaches during the course of ovacancer.展开更多
Objective： MGMT protein expression has been associated with tumor resistance to alkylating agents. The objective of this paper is to construct the RNA interference vector which can specifically induce the expression ...Objective： MGMT protein expression has been associated with tumor resistance to alkylating agents. The objective of this paper is to construct the RNA interference vector which can specifically induce the expression silence of human DNA repair gene hMGMT. Methods： The hMGMT specific siRNA expression cassette was made by two steps PCR, linked with pUCI 9 to get pU6-MGMTi, co-transfected with pEGFP-CI into 16HBE and screened by G418. The MGMT mRNA and protein levels were detected by RT-PCR and Western Blot respectively. Results： hMGMT specific RNA interfere vector pU6-MGMTi was constructed successfully. In transfected 16HBE cells MGMT mRNA level could hardly be detected and the protein level was only 10% of control. Conclusion： MGMT specific RNAi expression cassette can effectively inhibit MGMT expression. MGMT silence cell line was built by co-transfection technology, which offered condition for studying the gene function of MGMT.展开更多
文摘Objective: To demonstrate O6- methylguanine- DNA methyltransferase (MGMT) and glutathione S- transferase (GST) activities by analyzing the sera separately obtained from patients with malignant ovarian tumors, benign ovarian tumors, and healthy individuals. Study Design: Fourty- nine patients with ovarian cancer, nine patients with benign tumors, and 22 healthy women were included in this study. Blood samples were obtained from all the subjects in the malignant- tumor, benign- tumor, and control groups. Patients with malignant tumors underwent second and third phlebotomies one week following the surgery and after the chemotherapy regimen, respectively. MGMT, GST, and protein levels were measured for each serum sample. GST activity of the samples was measured by the method of Habig et al. using l- chloro- 2- 4 dinitrobenzene (CDNB) as substrate. MGMT activity was measured by the transfer of radio labelled methyl groups from a prepared MG- DNA substrate to the enzyme fraction of serum. Protein concentration was measured by biuret method. Results: Our work demonstrated that untreated patients with malignant ovarian tumors revealed significantly greater MGMT and GST activities in their sera than did both healthy individuals and patients with benign ovarian tumors, while no significant difference was found between the healthy group and the patients with benign ovarian tumors with respect to their sera MGMT and GST activities. GST activity following chemotherapy was significantly lower than the postoperative values preceding chemotherapy. A relationship between sera MGMT and GST activities, tumor histology and pathology was not found in this study. Conclusion: Our work suggests the fact that detection of sera MGMT and GST activities is important in diagnostic and therapeutic approaches during the course of ovacancer.
文摘Objective： MGMT protein expression has been associated with tumor resistance to alkylating agents. The objective of this paper is to construct the RNA interference vector which can specifically induce the expression silence of human DNA repair gene hMGMT. Methods： The hMGMT specific siRNA expression cassette was made by two steps PCR, linked with pUCI 9 to get pU6-MGMTi, co-transfected with pEGFP-CI into 16HBE and screened by G418. The MGMT mRNA and protein levels were detected by RT-PCR and Western Blot respectively. Results： hMGMT specific RNA interfere vector pU6-MGMTi was constructed successfully. In transfected 16HBE cells MGMT mRNA level could hardly be detected and the protein level was only 10% of control. Conclusion： MGMT specific RNAi expression cassette can effectively inhibit MGMT expression. MGMT silence cell line was built by co-transfection technology, which offered condition for studying the gene function of MGMT.
