Inhibitory Effects of Cyclooxygenase-2 Inhibited by shRNA on the Growth and Angiogenesis of Human Liver Cancer Cell Subcutaneous Xenograft Tumors in Nude Mice

Objective: To investigate the inhibitory effects of recombinant interference plasmid pshRNA-COX-2 on the growth and angiogenesis of human liver cancer cell Hep3B subcutaneous xenograft tumors in nude mice.Methods: The COX-2 mRNA and protein expressions were measured by reverse transcription polymerase chain reaction(RT-PCR) and Western blot,the VEGF mRNA expression was detected by RT-PCR after Hep3B cells were transfected with plasmid pshRNA-COX-2 and selected.Selected Hep3B cells were transplanted into the subcutaneous tissue of nude mice.Xenograft tumor volume was measured every three days and growth curves of tumors were drawn.The mice were killed after four weeks.The expression of COX-2 protein and microvessel density(MVD) in xenograft tumors were observed by immunohistochemistry.Results: Compared to the Hep3B cells without transfected by plasmid pshRNA-COX-2,the inhibition rates of COX-2 mRNA and protein expressions were 65.3% and 52.8% respectively in the pshRNA-COX-2 group(P0.05),the inhibition rate of VEGF mRNA expression was 56.5% in the pshRNA-COX-2 group(P0.05).The tumor volume in the pshRNA-COX-2 group was apparently smaller than that of the pshRNA-HK group and the untreated group(P0.01).The COX-2 score and MVD in the pshRNA-COX-2 group were significantly lower than that of the pshRNA-HK group and the untreated group(P0.01).Conclusion: The plasmid pshRNA-COX-2 can significantly inhibit the growth and angiogenesis of human liver cancer cell Hep3B subcutaneous xenografts in nude mice through inhibiting COX-2 expression.