Pan-cancer analysis reveals the prognostic potential of THAP9/THAP9-AS1 Sense-Antisense gene pair in human cancer

Human THAP9 is a domesticated transposon homologous to the Drosophila P-element transposase (DmTNP). However, the exact functional role of THAP9 is unknown. THAP9-AS1 (THAP9-anti sense1) is a lncRNA involved in various cancers. Together they are arranged head-to-head on opposite DNA strands forming a sense and anti-sense gene pair. No studies have analyzed THAP9 and THAP9-AS1 from a pan-cancer perspective. First, we analyzed the bidirectional promoter region between THAP9 and THAP9-AS1 for core promoter elements and CPG Islands. Moreover, we analyzed the expression, prognosis, and biological function of the two genes across different types of tumors included in The Cancer Genome Atlas and GTEx datasets. The results showed that the expression of both genes varies in different tumors. Expression of the THAP9 and THAP9-AS1 gene pair was observed to be strongly correlated with prognosis in patients with tumors; higher expression of the two genes was usually linked to poor overall and disease-free survival. Therefore, they may serve as a potential biomarker of clinical tumor prognosis. Further, we performed gene coexpression analysis using WGCNA followed by differential gene correlation analysis (DGCA) across 22 cancers to study which genes share the expression pattern THAP9 and THAP9-AS1 and if their interacting partners change in various conditions. Gene ontology & KEGG pathway analysis of genes coexpressed with the two genes identified gene enrichment related to DNA binding and Herpes simplex virus 1 infection.