Effect Of ERK1/2 Kinase Inhibitor PD98059 On The Expressions Of Reck, MMP-9 On Gastric Cancer Cells Line MGC-803

Objective:To investigate the effect of ERK1/2 in gastric cancer invasion and metastasis inhibiting by studying the regulation function of PD98059, the ERK1/2 signal inhibitor, on the expression of RECK and MMP-9 in gastric cancer cells MGC-803.Methods:Gastric cancer cells MGC-803 in logarithmic phase were synchronized and then divided into several groups depending on the concentration(5,10, 25, 50, 100μmol /L) and action time(2, 4, 12, 24, 48h) of PD98059.(1) The proliferation of gastric cancer cells MGC-803 was observed by methyl thiazolyl tetrazoliym(MTT) assay. Selecting the appropriate drug density to carry on the next step of the experiment.(2) P-ERK expression was determined by Western-blot, in that was the activation of ERK1/2 which was measured by the extent of ERK phosphorylation.(3) The expressions of RECK and MMP-9 mRNA and protein were determined by Reverse Transcription- Polymerase Chain Reaction(RT-PCR) and Western-blot .Results:(1) MTT assay showed the proliferation of gastric cancer cells MGC-803 could be inhibited by PD98059. And the inhibition was concentration-dependent at time point 12, 24 and 48h(5-100μmol/L), while it was time-dependent in the concentration of 25, 50 and 100μmol/L(24h).The effective concentration of PD98059 was 25μmol/L, in which the effective time was 24h. (2) Western-blot assay showed that ERK1/2 phosphorylation was suppressed by PD98059, that is ERK1/2 could be inactivated by the downregulation of P-ERK1/2.(3) RT-PCT assay and Western-blot assay showed that the expressions of RECK mRNA and protein were increased but the MMP-9 mRNA and protein were decreased by PD98059 in a concentration-dependent (25-100μmol/L) and time-dependent (12-48h) manner.Conclusions:(1) PD98059 can inhibit the proliferation and growth of human gastric cancer cells MGC-803.(2) PD98059 can up-regulate the expression of RECK, but down-regulate the expression of MMP-9, that is the invasion and metastasis of gastric cancer cells could be suppressed by inhibiting the ERK1/2.