Effect of VCAM-1 gene silencing mediated by lentiviral vector on growth of xenograft tumors of human tongue squamous cell carcinoma in nude mice

Objective: To investigate the inhibitory effect of vascular cell adhesion molecule-1 (VCAM-1) gene silencing on the growth of xenograft tumors of human tongue squamous cell carcinoma in nude mice.Methods: Murine subcutaneous xenograft tumor models of human tongue squamous carcinoma Tca-8113 cells were established in nude mice. The mice were randomly divided into three groups: interference group [injected with lentiviral particles of small hairpin RNA (shRNA) targeting VCAM-1 gene (VCAM-1-shRNA) into xenograft tumors], negative control group (injected with lentiviral particles of scramble RNA) and blank control group (injected with normal saline). Then the tumor growth in nude mice was observed, and the tumor growth curve was drafted. After injection for 3 weeks, all of the mice were sacrificed, then the xenograft tumors were removed and the weight of the tumor was measured. The tumor inhibitory rate was calculated. The morphological features of xenograft tumors were observed by HE staining. The expression level of VCAM-1 protein and the microvessel density (MVD) of tumor tissues were detected by immunohistochemistry method. The correlation between VCAM-1 expression and MVD was analyzed.Results: The growth of xenograft tumor in the interference group was significantly decreased as compared with those in the negative control and the blank control groups (both P < 0.05). The inhibitory rate of tumor weight in the interference group was 50.0%. The morphological features of xenograft tumors in three groups were consistent with the characteristics of squamous cell carcinoma. The expression level of VCAM-1 protein and MVD value in the interference group were decreased as compared with those in the negative control and blank control groups (all P < 0.01). The VCAM-1 protein expression was positively correlated with MVD (r = 0.834, P < 0.05).Conclusion: The lentivirus-mediated VCAM-1-shRNA interference can inhibit the growth and angiogenesis of xneograft tumors of human tongue squamous cell carcinoma in nude mice by silencing VCAM-1 gene expression. It is suggested that VCAM-1 may be a potential target of gene therapy for oral squamous cell carcinoma. DOI:10.3781/j.issn.1000-7431.2015.11.294