Targeting miR-21 with AS-miR-21 suppresses aggressive growth of human tongue squamous cell carcinoma in vivo

MicroRNAs (miRNAs) are involved in many human malignant tumors. Notably, miR-21 was identified to contribute to tumorigenicity. To investigate the repressive effect of targeting miR-21 with AS-miR-21 on proliferation of tongue squamous cell carcinoma (TSCC). We established the Tca8113-luc cell line with stable luciferase expression using pGL6-luciferase (pGL6-luc) plasmid transfection. TSCC xenograft models were characterized by high tumorigenicity rate and stable growth. Intratumor injection of Oligofectamine™-mediated AS-miR-21 significantly inhibited TSCC growth. The suppression of malignant phenotype was also accompanied by decreased photon signals, rare necrosis foci, smaller nucleuses, weakly stained nucleuses, atypia reversal and tumor angiogenesis reduction. Additionally, miR-21 expression was markedly decreased in TSCC xenografts and the apoptotic index was increased. Intratumor injection of AS-miR-21 into TSCC xenografts could reduce expression of miR-21, promote apoptosis of TSCC cells and inhibit TSCC proliferation.