Abstract 5172: Mirna Lncrna Network Associated with Response to Cemiplimab in Cutaneous Squamous Cell Carcinoma

Abstract Introduction: For advanced cSCC the use of immunological therapies relies on the biology of the tumor, characterized by high mutational burden. However, although the anti-PD1 cemiplimab showed to be a promising treatment option, future research focusing on the use of biomarkers to predict treatment response are needed. Since increasing number of studies has revealed the crucial roles of non-coding RNAs, such as miRNAs and lncRNAs in the development of SCC, the present study had the purpose to explore the lncRNA-miRNA-mRNA networks associated with response to anti-PD1. For this purpose the experimental procedure envisaged a preliminary in silico analysis followed by the investigation of identified miRNA and lncDNA in liquid biopsy. Methods: For the in silico study, GSE139505 RNA-sequencing raw data have been retrieved from SRA, including 7 Healthy Samples and 9 cSCC biopsies. Two matrices have been prepared, including coding genes and lncRNAs. Normalized coding gene matrix have been used as input to perform GSEA. Coexpression analysis between lncRNAs and Core enrichment genes resulting from GSEA was performed. Biological network including validated miRNA-gene interactions (TarBase) and lncRNA-miRNA interactions (lncBase) has been built-up through Cytoscape. MCODE analysis to identify subnetwork with the closest relationships was performed. The quantification of identified miRNAs (miR-125a, miR-125b, miR-148a, miR-148b) and lnc (AF131217.1, RP11-362F19.1, PVT1, LINC00665) was performed in pre-therapy plasma samples of 34 cSCC patients, categorized according to clinical response to cemiplimab, in responders and non-responders. miRNA-specific RT primers were used for reverse transcription by ddPCR. Results: The computational analysis revealed a significant enrichment of two gene sets related to immunotherapy, namely the Reactome_PD1_signaling and WP_Cancer_Immunotherapy_by_PD1_blockade. The coespression analyses highlighted more than 600 correlations gene-miRNA-lncRNA for the two above-mentioned genesets. CD4-miR-125a/b and AF131217.1/RP11-362F19.1 are strongly correlated for the first one; whilst, regarding the latter one, CD274/HLA-A with mir-148a/b and PVT1/LINC00665 and JUN with mir-125a/b and AF131217.1/RP11-362F19.1 were found. The validation in cSCC plasma samples evidenced the significant correlation between mir-148a/b and PVT1/LINC00665 and an higher expression of all miRNAs in responders respect to non-responders. The longitudinal study assessing the correlation between miRNA expression and response to cemiplimab is ongoing. Conclusion: Preliminary analysis in pre-therapy plasma samples of cSCC validated the in silico data highlighting the inverse correlation between miR-148a/b and lnc (PVT1 and LINC00665). Further investigation will confirm the role of miR125a/b and miR148a/b as predictors of cemiplimab response. Citation Format: Letizia Porcelli, Simona De Summa, Rossella Fasano, Michele Guida, Tommaso M. Marvulli, Tania Rafaschieri, Giuseppe De Palma, Simona Serratì, Roberta Di Fonte, Ivana De Risi, Sabino Strippoli, Stefania Tommasi, Amalia Azzariti. miRNA lncRNA network associated with response to cemiplimab in cutaneous squamous cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5172.