Background: In this study, influence caused by expression plasmids of connective tissue growth factor(CTGF) and tissue inhibitor of metalloproteinase-1 (TIMP-1) short hairpin RNA (shRNA) on mRNA expressionof CTGF,TIMP-1,procol-α1 and PCIII in hepatic tissue with hepatic fibrosis, a precancerous condition, in ratsis analyzed. Materials and
Methods: To screen and construct shRNA expression plasimid which effectivelyinterferes RNA targets of CTGF and TIMP-1 in rats. 50 cleaning Wistar male rats are allocated randomly at 5different groups after precancerous fibrosis models and then injection of shRNA expression plasimids. PlasmidpsiRNA-GFP-Com (CTGF and TIMP-1 included), psiRNA-GFP-CTGF, psiRNA-GFP-TIMP-1 and psiRNADUO-GFPzeo of blank plasmid are injected at group A, B, C and D, respectively, and as model control groupthat none plasimid is injected at group E. In 2 weeks after last injection, to hepatic tissue at different groups,protein expression of CTGF, TIMP-1, procol-α1and PC III is tested by immunohistochemical method and,mRNAexpression of CTGF,TIMP-1,procol-α1 and PCIII is measured by real-time PCR. One-way ANOVA is used tocomparison between-groups.
Results: Compared with model group, there is no obvious difference of mRNAexpression among CTGF,TIMP-1,procol-α1,PC III and of protein expression among CTGF, TIMP-1, procol-α1,PC III in hepatic tissue at group injected with blank plasmid. Expression quantity of mRNA of CTGF, TIMP-1,procol-α1 and PCIII at group A, B and C decreases, protein expression of CTGF, TIMP-1, procol-α1, PC IIIin hepatic tissue is lower, where the inhibition of combination RNA interference group (group A) on procol-α1mRNA transcription and procol-α1 protein expression is superior to that of single interference group (group Band C) (P<0.01 or P<0.05).
Conclusions: RNA interference on CTGF and/or TIMP-1 is obviously a inhibitingfactor for mRNA and protein expression of CTGF, TIMP-1, procol-α1 and PCIII. Combination RNA interferenceon genes of CTGF and TIMP-1 is superior to that of single RNA interference, and this could be a contributionfor prevention of precancerous condition.