Transcriptomic Profiling of Salivary Gland Carcinomas in Nigerian Patients: Toward Identification of Novel Therapeutic Targets

Salivary gland carcinomas are a heterogeneous group of rare malignancies with diverse molecular subtypes and unpredictable clinical behavior. While comprehensive transcriptomic datasets have been generated for European and North American patient populations, African salivary gland carcinoma data are absent from international genomic repositories. This original PhD study performs RNA sequencing-based transcriptomic profiling of salivary gland carcinomas from Nigerian patients, identifying differentially expressed genes, oncogenic pathway dysregulation, and potential novel therapeutic targets. Forty formalin-fixed paraffin-embedded salivary gland carcinoma specimens from LUTH Lagos, UBTH Benin, UCTH Calabar, and UNTH Enugu, representing three geopolitical zones, were subjected to RNA extraction and whole transcriptome sequencing using an Illumina short-read platform. Histological subtypes included mucoepidermoid carcinoma, adenoid cystic carcinoma, acinic cell carcinoma, and polymorphous adenocarcinoma. Differential expression analysis, gene ontology enrichment, and pathway analysis were performed using established bioinformatics pipelines. Results demonstrate significant upregulation of genes in the NOTCH and MYB signaling pathways in adenoid cystic carcinoma specimens, consistent with global literature. Notably, novel upregulation of SPP1 and IGFBP3 were identified in mucoepidermoid carcinoma specimens from Nigerian patients, not previously reported in non-African datasets. These candidates were validated by quantitative PCR and correlated with clinical stage and recurrence. The study pioneers African salivary gland carcinoma transcriptomics, contributes population-specific molecular data to the global cancer research commons, and proposes novel therapeutic target candidates for future functional validation studies. Keywords: salivary gland carcinoma, transcriptomics, RNA sequencing, therapeutic targets, Nigeria.