Spatial Transcriptome Analysis Reveals Factors Involved in Actinic Cheilosis Transformation to Squamous Cell Carcinoma of the Lip.

Abstract

Lip squamous cell carcinoma (SCC) often arise from actinic cheilitis. However, factors driving oncogenic transformation and determinants of lip SCC differentiation are unclear. This study investigated differences between lip SCC and premalignant actinic cheilitis and factors related to tumor differentiation. We included patients who received biopsies for actinic cheilitis that later progressed to lip SCC. Moreover, well-differentiated lip SCC and moderately-to-poorly differentiated lip SCC were selected for spatial transcriptomic analysis, using PanCK and CD45 as morphology markers. In PanCK⁺ tumor areas, we detected 5 upregulated differentially expressed genes (DEGs) (KLK13, MGST1, LNX1, NDRGZ, and HMOX1) and 1 downregulated DEG (HOXD11) in lip SCCs compared with premalignant lesions. Endosomal transport, lysosomal transport, macroautophagy, and wound healing pathways were significantly upregulated in lip SCC compared to actinic cheilitis. Furthermore, proteolysis- and hypoxia-related DEGs were found in moderately-to-poorly differentiated lip SCC compared to well-differentiated lip SCC. General cancer-associated fibroblast markers (p = 0.021) were increased in actinic cheilitis preceding moderately-to-poorly differentiated lip SCCs compared to actinic cheilitis preceding well-differentiated lip SCCs, which was validated in immunohistochemical staining. This observation could expand our understanding of the changes in the microenvironment composition during lip SCC carcinogenesis and according to lip SCC differentiation.