Change of high mobility group box 1 and effect of drainage of intestine lymph fluid on rat gut barrier during intestine ischemia-reperfusion

Abstract

Objective To investigate the effects of recombinant human growth hormone(rhGH)on human liver cancer cells expressing different growth hormone receptor(GHR)in vitro.Methods The expressions of GHR on human liver cancer cell lines HepG-2,SMMC7721,and QGY-7701 were detected by immunohistochemical method.Each cell line was assigned to four groups according to the treatment manner:untreated group,50 ng/ml rhGH treated group,100 ng/ml rhGH treated group,and 200 ng/ml rhGH treated group.By methods of methyl thiazol tetrazolium(MTr)assay,5(6)-(N-Succinimidyloxycarbonyl)-3',6'-0,0'-diacetylfluorescein(CFSE)staining,and enzyme-linked immunosorbent assay(ELISA),effects of different concentrations of rhGH on the cell growth,proliferation rate,and excretion of insulin-like growth factor-1(IGF-1)of human liver cancer cell lines were analyzed.The expression of GHR in human liver cancer cell lines pretreated by rhGH was detected by fluorescence and radioligand assays.Results GHR was highly expressed in HepG-2 cells.Compared with the untreated group,the 24-hour growth rates in 50,100,and 200 ng/ml rhGH treated group significantly increased by 107.705%,114.181%,and 107.406%(P＜0.05),and the 48-hour growth rates significantly increased by 109.594%,114.156%,and 109.292%(P＜0.05).The fluorescence intensities of CFSE significantly decreased(P＜0.05).The concentrations of IGF-1 in the four groups were(173.86±27.46)pg/ml,(236.94±19.07)pg/ml,(247.16±14.56)pg/ml,and(217.94±33.61)pg/ml,respecetively;compared with the untreated group,it significantly increased in groups pretreated with different concentrations of rhGH(P＜0.05).By fluorescence,the expressions of GHR significantly increased in the treated groups(P＜0.05).By radioligand assays,the GHR site of the untreated group was(7.51±0.54)×103/cell,with the sites of 50,100,and 200 ng/ml rhGH treated group were(8.44±0.24)x103/cell,(9.40±0.51)×103/cell,and(8.33±0.31)×103/cell (P＜0.05)respectively.However,no obvious effect of rhGH on SMMC7721 was observed,in which the expression of GHR was low;no expression of GHR was detected in QGY-7701(P＞0.05).Conclusions rhGH can promote the growth and increase the expression of GHR in liver cancer cell line HepG-2 in which GHR is highly expressed.However,such effects are not notable in cell line QCY-7701 and SMMC7721 in which the expression of GHR was low or undetectable in vitro. Key words: Recombinant human growth hormone; Growth hormone receptor; Insulin-like growth factor-1; Liver neoplasms