Effects of epidermal growth factor on the growth of human gastric cancer cell and the implanted tumor of nude mice

AIM:Epidermal growth factor(EGF)plays an important rolein the regulation of gastrointestinal tissue growth anddevelopment,and it can stimulate epithelial proliferation,cell differentiation and growth.It has been established thatthe EGF can promote gastric cytoprotection and ulcerhealing.But the potential ability of EGF to regulate thegastric cancer growth is unknown.This study is toinvestigate the influence of EGF on human gastric cancercell and the implanted tumor growth of nude mica.METHODS:The cell growth rates of human gastricadenocarinoma cell lines MKN-28,MKN-45,SGC-7901 andnormal human gastric epithelial cells 3T3 were assessedwhen incubated with recombinant human EGF(rhEGF,0.05,0.1,0.5,1.0,10,50,100 mg.L-1)using MTT method.The cells of MKN-28,MKN-45,SGC-7901(gastric cancertissue 1.5 mm~3)were implanted in the BALB/cA nude micefor 10 days.The EGF was given intreperitoneally(15,30,60μg.kg-1)for 3 weeks.The body weights of the tumor-bearing animals and their tumor mass were measuredafterwards to assess the mitogenic effect of rhEGF in thenude mice.RESULTS:Within the concentration range of 0.05-100 mg.L-1,rhEGF could increase the cell growth of normal 3T3 cells(cell growth rate 100% vs 102.8%,P<0.05),but partiallyrestrain the gastric cancer cell growth.The latter effect wasrelated to cell differentiation.In 15-60μg/kg rhEGF groups,the mean implanted tumor mass of MKN-28 cell were 1.75g,1.91 g,2.08 g/NS group 1.97g(P>0.05),the mean tumormass of SGC-7901 cell were 1.53g,1.07g,1.20g/NS group1.07g(P>0.05),and for MKN-45 cell,the tumor masswere respectively 1.92g,1.29g,1.77g/NS group 1.82g(P>0.05).So rhEGF had no obvious effect on implantedMKN-28,SGC-7901 and MKN-45 tumor growth.CONCLUSION:EGF has no stimulating effect on the humangastric cancer cell growth neither in vitro nor in vivo.