Cytological and architectural alterations in the progression and treatment of oral leukoplakia in pre-clinical model

Abstract

Squamous cell carcinoma (SCC) in the head and neck is one of the most common malignancies in the world. One way of preventing it is by early detection and treatment of oral potentially malignant lesions (OPML). One of the most common OPMLs is oral leukoplakia (OLP); its malignant transformation rate is related to its clinical form and the presence or absence of epithelial dysplasia. To date, there is no evidence that any treatment for OLP reduces its progression to oral cancer. The objective of this study will be: to evaluate whether treatments with artemisinin and/or with Rubus occidentalis extract (BRB) prevent macroscopic, cytological, and architectural alteration of the epithelial cells under 4-NQO action, simulating a scenario of non-smoking cessation. Material and methods: 72 male mice will receive water with 4-Nitroquinoline N-oxide for 16 weeks. In the 8th week, after the detection of OLPs, the animals will be treated with a subepithelial injection of artemisinin weekly and/or by BRB in the daily feed. In the 12th and 16th weeks, the animals will be euthanized, and the collected tongues will be analyzed clinically and photographed. The classification of the degree of epithelial dysplasia will be performed under conventional light microscopy. Epithelial dysplasia will be analyzed for cellular alterations: increased nucleus/cytoplasm ratio, nuclear hyperchromatism, increased number of mitoses, aberrant mitosis figures, architectural changes, loss of cellular polarity, dyskeratosis, and restricted drop-like epithelial projections in the lower 1/3 of the epithelium (mild dysplasia), in the middle 1/3 (moderate dysplasia) or up to the upper third (severe dysplasia). And finally, squamous cell carcinoma when atypical epithelial cells rupture the basal membrane and invade the connective tissue/stroma. The appropriate statistical tests will be used with ± = 0.05. (AU)