A Single‐Cell and Spatial Transcriptomic Analysis of Conventional Ameloblastoma

OBJECTIVE: To understand the cellular and spatial composition of conventional ameloblastoma and its alteration after marsupialization treatment. MATERIALS AND METHODS: We applied single-cell RNA sequencing and spatial transcriptomics on pre- and post-marsupialization conventional ameloblastoma slices, followed by cluster, trajectory, network analysis, and immunofluorescence validation. RESULTS: We found a continuous cell trajectory from pre-marsupialization epithelium-like cell types to post-marsupialization mesenchyme-like cell types. Comparison with our recently established human embryonic dental cell atlas revealed that epithelium-like cells resembled the most primitive outer enamel progenitors, whereas mesenchyme-like cells did not resemble any embryonic mesenchymal cells, representing a differentiated and abnormal state. Transcription factors DLX5 and TWIST1, together with their target genes, showed profound alterations that paralleled the epithelium-to-mesenchyme transition (EMT). We verified the existence of EMT by double immunofluorescence of two EMT markers FN1 and VIM, and verified the specific expression of KRT15 in pre-marsupialization tissues. Lastly, mesenchyme-derived proteins MMP13 and THBS2 exert feedback regulatory effects on EMT. CONCLUSIONS: We constructed the cellular and spatial landscape of conventional ameloblastoma before and after marsupialization. Our findings indicate that the epithelial-mesenchymal transition (EMT) process, potentially regulated by DLX5 and MMP13, contributes to the treatment effect of marsupialization.