Aim To explore the effect of Cx43 over-expression on proliferation of C6 cells and its mechanisms by transfecting pCMV-Cx43cDNA plasmid into C6 cells.Methods pCMV-Cx43cDNA plasmid was transfected into C6 cells by liposome to up-regulate the expression of Cx43, and C6 cells with over-expression of Cx43 was stably cloned by using G418.Determination of cell doubling time and soft agar colony formation assay to detect the degree of cell proliferation.The cells were treated with ERK1/2 specific blocker PD98059(30 μmol·L-1) and p38MAPK specific blocker SB202190(10 μmol·L-1)respectively, the expression of Cx43, p-Cx43, p-ERK1/2 and p-p38MAPK of each group were detected by Western blot, and the activity of each group was detected by MTT Assay.Results pCMV-Cx43cDNA plasmid was transfected into C6 cells successfully.Cell lines with over-expression Cx43(C6-Cx43) or empty vector (C6-pCMV) were stably selected by using G418.Determination of cell doubling time and soft agar colony formation experiments showed that the proliferative rate and the colony number of C6-Cx43 group were significantly decreased, compared with that of C6 group and C6-pCMV group(P<0.01);ERK1/2, p38MAPK specific blockers were treated with each group,Western blot showed that the expression of Cx43 protein was increased(P<0.01), while p-Cx43 protein was decreased (P<0.05) in C6-Cx43+PD98059 group and C6-Cx43+SB202190 group,compared with that of C6-Cx43 group.Conclusion Cx43 may decrease the proliferation of glioma cells through ERK1/2, p38MAPK pathways.

Objective The effect of different doses of ethylnitrosourea(ENU)and cyclophosphamide(CP)on the loss rate of CD59 on peripheral blood erythrocytes was explored to optimize the detection method of Pig-a gene mutation. Methods According to the weight and loss rate of CD59 on peripheral blood erythrocytes,rats were divided into 4 groups:the control group,CP 40 mg/kg group,ENU 10 mg/kg group and ENU 40 mg/kg group(n=6). The control group was injected i.p. with PBS,other groups were injected i.p. with corresponding solutions. The body weight of rats on days 0,7,14,21, 28, 42 and 56 were recorded. At the same time, blood samples were collected and incubated with antibodies,and the loss rate of RBCCD59-was detected by flow cytometry. Results Compared with the control group, at different time points, the body weight and weight gain of ENU 10 mg/kg group and ENU 40 mg/kg group had no statistically significant difference(P > 0.05),while those in the CP 40 mg/kg group were significantly decreased(P <0.05). The loss rate of RBCCD59-was significantly increased in the CP 40 mg/kg group at 28,42 and 56 days, ENU 10 mg/kg group at 42 and 56 days,and ENU 40 mg/kg group at 7,14,21,28,42 and 56 days,(P < 0.05). The results showed a dose-response relationship. Conclusions Under the conditions of this Pig-a mutation detection method,ENU is superior to CP on raising loss rate of RBCCD59-,ENU 40 mg/kg is better than 10 mg/kg,and 28 days is suitable as the test period.