ABSTRACT
<p><b>OBJECTIVE</b>To explore the possibility of treating solid tumor with siCD44.</p><p><b>METHODS</b>Human nasopharyngeal carcinoma cell CNE-2L2 with high expression of CD44 was used in this study. The malignant activities of cells were examined by colony formation test, tumorigenesis, and lung metastasis of the tumor in nude mice. Ad5-siCD44 was constructed and adenoviruses were produced in 293 cells. CNE-2L2 cells were subcutaneously inoculated into nude mice. When tumors grew to 50-100 mm3, Ad5-siCD44 was injected into tumors, and Ad5-egfp and PBS were also injected as controls. The size and weight of tumors were compared after 2 weeks.</p><p><b>RESULTS</b>Suppression of CD44 expression profoundly inhibited the malignant activities of CNE-2L2 cell. The average sizes of the tumors were (3.139 +/- 0.850), (3.612 +/- 0.888), and (1.512 +/- 0.742) cm3 after the intra-tumor injection of PBS, Ad5-egfp, and Ad5-siCD44, respectively, after two weeks. Significant difference was found between Ad5-siCD44 group and control groups (P < 0.05). The average weights were (2.28 +/- 0.73), (1.83 +/- 0.26), and (1.20 +/- 0.64) g, respectively, and significant difference was also found between Ad5-siCD44 group and control groups (P < 0.05).</p><p><b>CONCLUSION</b>Intra-tumor injection of Ad5-siCD44 can exhibit the therapeutic effect on the tumor inoculated with CNE-2L2 cells with high expression of CD44 in nude mice.</p>