Oral squamous cell carcinoma (OSCC) is a common malignancy with a growing worldwide incidence and prevalence. The N-myc downstream regulated gene (NDRG) family of NDRG1, 2, 3, and mammary serine protease inhibitor (Maspin) gene are well-known modulators in the neoplasia process. Current research has considered iron chelators as new anti-cancer agents; however, the anticancer activities of iron chelators and their target genes in OSCC have not been well investigated. We showed that iron chelators (Dp44mT, desferrioxamine (DFO), and deferasirox) all significantly inhibit SAS cell growth. Flow cytometry further indicated that Dp44mT inhibition of SAS cells growth was partly due to induction of G1 cell cycle arrest. Iron chelators enhanced expressions of NDRG1 and NDRG3 while repressing cyclin D1 expression in OSCC cells. The in vivo antitumor effect on OSCC and safety of Dp44mT were further confirmed through a xenograft animal model. The Dp44mT treatment also increased Maspin protein levels in SAS and OECM-1 cells. NDRG3 knockdown enhanced the growth of OECM-1 cells in vitro and in vivo. Our results indicated that NDRG3 is a tumor suppressor gene in OSCC cells, and Dp44mT could be a promising therapeutic agent for OSCC treatment.

Conventional methods that have been developed to immobilize the mouth and tongue for radiotherapy (RT) in head and neck cancer (HNC) treatment have been unsatisfactory. We, therefore, developed three-dimensional (3D), customizable, silicone bite blocks and examined their clinical feasibility. For HNC patients, before RT, the 3D printed bite blocks were fabricated based on primary computed tomography (CT) simulation images. The placement of the 3D bite blocks was followed by a secondary CT simulation before RT planning was finalized. Dosimetric parameters and positioning verification achieved with the propose bite blocks were compared with conventional universal oral corks. The 3D printed bite blocks were conformal to the occlusal surface, ensuring immobilization of the tongue without eliciting a gag reflex, and an elastic and firm texture that supports opening of the mouth, with a smooth surface with tolerable intraoral tactility. The dosimetry of patients using the proposed bite blocks showed better coverage of the planning target volume and surface of a tumour bed along with reduction in normal tissue doses. Good concordance of positioning by 3D printed bite blocks during the RT course was verified. The 3D printed bite blocks with silicone might be a customizable, safe, and practical advanced technology in RT for HNC.