RT Journal Article SR Electronic T1 Intravenous Delivery of miR-21 Inhibitor in Mice With Head and Neck Squamous Cell Carcinoma JF Anticancer Research JO Anticancer Res FD International Institute of Anticancer Research SP 3487 OP 3491 DO 10.21873/anticanres.16525 VO 43 IS 8 A1 ISHINAGA, HAJIME A1 YASUMA, TARO A1 D’ALESSANDRO-GABAZZA, CORINA N. A1 D’ALESSANDRO, VALERIA FRIDMAN A1 TODA, MASAAKI A1 GABAZZA, ESTEBAN C. A1 TAKEUCHI, KAZUHIKO YR 2023 UL http://ar.iiarjournals.org/content/43/8/3487.abstract AB Background/Aim: Synthetic miRNA inhibitors have recently attracted considerable interest as potential therapeutic agents for head and neck squamous cell carcinoma. However, due to the lack of evidence, no attempts have been made to deliver these inhibitors intravenously for squamous cell carcinoma. Materials and Methods: This study investigated whether intravenous administration of a miR-21 inhibitor with lipid nanoparticles could suppress HNSCC in xenograft mice. Head and neck squamous cell carcinoma xenograft mice were intravenously injected with Invivofectamine 3.0® containing either a miR-21 inhibitor or a control inhibitor, using a modified protocol for nucleic acid encapsulation. Quantitative PCR was used to measure the expression level of intratumoral miR-21. And TdT-mediated dUTP nick-end labeling (TUNEL) immunohistochemistry was used to assess cell death. Results: Intravenous injection of miR-21 inhibitor significantly inhibited head and neck squamous cell carcinoma growth and miR-21 expression in tumor tissue compared to the control inhibitor. TUNEL assay showed significant apoptosis of tumor cells after intravenous administration of miR-21 inhibitor. Conclusion: Intravenous delivery of a miR-21 inhibitor with lipid nanoparticles is a promising approach for miRNA-targeted therapy of head and neck squamous cell carcinoma.