Overexpression of Chk1/2 gene affects G2/M arrest in MGC803 cells induced by diallyl disulfide / 中国药理学通报

ABSTRACT

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.