Therapeutic, Clinicopathological, and Molecular Correlates of PRKACA Expression in Gastrointestinal Cancers

Background/Objectives: PRKACA alterations have clear diagnostic and biological roles in the fibrolamellar variant of hepatocellular carcinoma and a potential predictive role in that cancer type. However, the roles of PRKACA have not been comprehensively examined in gastric and colorectal cancers (GC and CRC). This study, therefore, sought to investigate the roles of PRKACA expression in GC and CRC. Methods: The clinico-genomic data of 441 GC and 629 CRC cases were analyzed for therapeutic, clinicopathological, and biological correlates using appropriate bioinformatics and statistical tools. Furthermore, the deregulation of PRKACA expression in GC and CRC was investigated using correlative and regression analyses. Results: The results showed that PRKACA expression subsets were enriched for gene targets of chemotherapeutics, tyrosine kinase, and β-adrenergic inhibitors. Moreover, high PRKACA expression was associated with adverse clinicopathological and genomic features of GC and CRC. Gene Ontology Enrichment Analysis also showed that PRKACA-high subsets of the GI cancers were enriched for the biological and molecular functions that are associated with cell motility, invasion, and metastasis but not cell proliferation. Finally, multiple regression analyses identified multiple methylation loci, transcription factors, miRNA species, and PRKACA copy number changes that deregulated PRKACA expression in GC and CRC. Conclusions: This study has identified potential predictive and clinicopathological roles for PRKACA expression in GI cancers and has added to the growing body of knowledge on the deregulation of PRKACA in cancer.