Gene Expression Patterns of Cutaneous Squamous Cell Carcinoma and Actinic Keratosis: Biomarkers Screening for Skin Disease Diagnosis

BACKGROUND: Actinic keratosis (AK) was an intraepidermal tumor which caused by ultraviolet irradiation-induced skin damage. OBJECTIVE: The aim was to screen biomarkers for development of skin disease by comparing the gene expression profiles between cutaneous squamous cell carcinoma (CSCC) and AK. METHODS: GSE45216 with 30 cutaneous squamous cell carcinoma patients and 10 actinic keratosis patients were downloaded and significance analysis of microarrays was processed to screen differently expressed genes (DEGs). Fisher's exact test was processed for DEGs enrichment. Pathway relationship network systematically reflected the signal conduction and synergism between enriched pathways based on Kyoto Encyclopedia of Genes and Genomes database. Gene co-expression network was constructed according to gene expression data. Quantitative real-time-PCR was used to verify screened biomarkers. RESULTS: Total 410 DEGs were screened and enriched into various functions, such as signal transduction and negative regulation of apoptotic process. They also participated into cytokine-cytokine receptor interaction and focal adhesion. The pathway relationship network was constructed with 27 nodes. Hub nodes with higher degree of this network were mitogen-activated protein kinase signaling pathway and apoptosis. The gene co-expression network was constructed with 39 nodes. Thereinto, hub node was ELOVL fatty acid elongase. The expression levels of ELOVL4 and HPGD were significantly higher in CSCC samples than that in AK samples, while the expression levels of INHBA and LAMC2 in CSCC samples were significantly lower than that in AK samples. CONCLUSION: These screened genes, including ELOVL4, HPGD, INHBA and LAMC2, played important roles in transformation from AK to CSCC.