Objective: To investigate the inhibitive role of lentivirus mediated MMP-9 gene silence in the growth of laryngeal cancer xenografts.
Method: The nude mouse model of laryngeal squamous carcinoma was established and RNA interference (RNAi) technic was used. Recombinant MMP-9-RNAi-Lentivirus was intratumoral injected while the empty vector lentivirus was taken as control. After the treatment, tumor inhibitive effect was observed and western-blot was used to test the expression of MMP-9 in the xenografts. Finally, the PCNA expression in xenografts were examined with immunohistochemistry to evaluate proliferation change of the Hep-2 cells.
Result: The average tumor weight was (1.484 +/- 0.391) g in group treated with MMP-9-RNAi-Lentivirus which was significantly lower than that (2.618 +/- 0.465) g in the control group (P < 0.05). The average tumor volume was (1.177 +/- 0.270) cm3 in group treated with MMP-9-RNAi-Lentivirus which was significantly lower than that (2.034 +/- 0.366) cm3 in the control group (P < 0.05) and the tumor inhibitive rate was 43.32%. Western-blot showed there were 7 cases of xenografts with MMP-9 protein negative expression and the other 3 cases were tested with weak positive expression in the treated group xenografts. Whereas all the 10 cases of xenografts were tested with MMP-9 positive expression in the control group. Immunohistochemistry showed PCNA index in treated group was (55.41 +/- 8.77)% which was obviously lower than that (77.04 +/- 6.91)% in control group (P < 0.01).
Conclusion: The growth and proliferation of laryngeal cancer could be inhibited by recombinant MMP-9-RNAi-Lentivirus.