RESUMEN
Aim To investigate the effects of diallyl di-sulfide( DADS) on G2/M arrest in Chk1/MGC803 and Chk2/MGC803 cells so as to establish stable human gastric cancer MGC803 cells with overexpression of Chk1/2 gene. Methods The colony formation, flow cytometry, RT-PCR and Western blot were used to de-tect the proliferation, cell cycle, and expression of Chk1/2 mRNA and protein, p-Chk1/2, CDC25C and cyclinB1, respectively. Results The colony formation showed that the colony forming efficiency in Chk1/MGC803 and Chk2/MGC803 cells treated by 30 mg· L-1 DADS was lower than in control group and vector group ( P <0. 05 ) . Flow cytometry demonstrated that 41. 3%, 57. 4%, 68. 9% and 42. 9% of G2/M cells in Chk1/MGC803 were increased than in MGC803 and Chk2/MGC803 , respectively after treated by DADS in 12,24, 36 and 48 h(P <0. 05). At the same time, RT-PCR disclosed that expression of Chk1 and Chk2 mRNA had no marked change. Western blot showed that total proteins of Chk1 and Chk2 and p-Chk2 had invisible change, but expression of p-Chk1 was up-reg-ulated, and CDC25C and cyclinB1 were down-regula-ted time-dependently in Chk1/MGC803 cells ( P <0. 05 ) . Conclusion DADS arrests MGC803 cells at G2/M by increasing p-Chk1 expression to cause down-regulation of CDC25C and cyclinB1 simultaneously.
RESUMEN
Objective:To investigate the expression of Plk1 ( Polo-like kinase 1 ) and Chk1/2 ( Checkpoint kinase 1/2 ) in primary hepatic carcinoma tissue and HepG2 cell. Methods: Using immunohistochemistry chemical method detected expression of Plk1,Chk1/2 protein in 40 cases of primary hepatic carcinoma tissue and 16 cases of non-tumor tissue of liver. Western blot was applied to detect the expression of Plk1 and Chk1/2 protein in HepG2 cells, and gray value was measured by using the quantitative analysis. Results:The positive rate of Plk1,Chk1/2 protein expression in primary hepatic carcinoma was 57. 5%,75. 0% and 22. 5%respectively,compared with positive rate in the liver of non-tumor tissue were 0%,25. 0% and 56. 3%. The expression of Plk1 and Chk1 protein in primary hepatic carcinoma tissue is higher than that in non-tumor tissue of liver,and the difference was statistically sig-nificant( PChk1>Chk2. Conclusion: Plk1,Chk1 protein in primary hepatic carcinoma was up-regulated,while Chk2 protein was down-regulated in these tissues. The expression degree was Plk1> Chk1>Chk2. There were relatively selective expression in primary hepatic carcinoma tissue of Plk1,Chk1 protein,then Plk1 and Chk1 might be ideal targets for therapy of primary hepatic carcinoma.