Small RNA sequencing of formalin-fixed paraffin embedded human skin biopsies reveals miRNA signatures for actinic keratosis and squamous cell carcinoma

Although RNA sequencing of FFPE specimens is challenging and requires further optimization, we identified several candidate microRNAs (miRNAs) across all 3 stages of keratinocytic intraepidermal neoplasia, including the upregulation of hsa-miR-145-5p, hsa-miR-30-5p, and hsa-miR-205-5p and downregulation of hsa-miR-486-5p against healthy controls. These miRNAs may serve as a potential diagnostic, prognostic, and therapeutic biomarkers for skin cancer. Future studies are needed to improve methods for FFPE analysis and to validate the key differences in miRNA signatures involved in skin cancer development.