Artemisinin and Rubus occidentalis extract action in the PD-1/PD-L1 pathway in the oral leukoplakia progression in preclinical model

Abstract

Squamous cell carcinoma (SCC) is a malignant neoplasm characterized by the abnormal proliferation and differentiation of epithelial cells in the head and neck region, which can develop from the progression of potentially malignant oral lesions, such as oral leukoplakia (OLP). The expression of the PD-L1 ligand in tumor cells, and its interaction with the PD-1 protein expressed in cytotoxic T cells, are observed in tumor immune escape, promoting tolerance and proliferation of cancer cells. The expression of PD-L1 in OLP suggests an association with progression to SCC, although this is still questionable. In this study, the objective will be to analyze the action of treatment with Artemisinin and Rubus occidentalis (BRB) extract, observing whether the progression from OLP to SCC is prevented through the hypoexpression of the PD-1/PD-L1 pathway. Seventy-two C57BL/6J female mice aged 4-6 weeks and weighing about 16-18g will be used in the study. They will be divided into 4 groups (n=8/group), with 2 different periods of euthanasia, and 3 periods in the group control. OLP induction will be performed through exposure to 4NQO in drinking water for 16 weeks. Around the 8th week, with the appearance of epithelial alterations, treatments with Artemisinin will be started through subepithelial injection, and 5% BRB extract via gavage. The degree of cell dysplasia will be analyzed in histological sections with H&E staining under light microscopy, as well as the analysis of other histological sections by immunohistochemical technique to verify PD-1 and PDL-1 expression, using monoclonal antibodies as biomarkers. IBM SPSS version 20.0 software and BioEstat 5.0 software will be employed for appropriate statistical analysis.(AU)