Role of Circular RNA CCDC66 and Serine/Threonine Kinase-2 (AKT2) in the Pathogenesis of Crohn’s Disease: A Potential Diagnostic Biomarker

Abstract

Background: Crohn’s disease (CD) is a long-term inflammatory disease of the bowel characterized by recurring environmental influences, including gut microbiota. While non-coding RNAs and intracellular kinases are implicated in inflammatory processes, their specific roles in CD remain unclear.Objectives: This study explored the involvement of circular RNA coiled-coil domain-containing 66 (circCCDC66) and serine/threonine kinase (AKT2) as potential biomarkers in CD pathogenesis.Patients and methods: A Cross-sectional case-control study involving 50 participants: 34 CD patients (17 active and 17 inactive) and 16 healthy controls. Disease activity was tested with the Simple Endoscopic Score for Crohn's Disease (SES-CD) and the Crohn's Disease Activity Index (CDAI). Plasma circCCDC66 levels were assessed by quantitative real-time PCR (qRT-PCR), while serum AKT2 concentrations were tested using ELISA.Results: CircCCDC66 expression was markedly higher in patients with CD than in control subjects, with no significant difference between active and inactive disease stages. AKT2 levels were elevated in CD; however, this increase did not reach statistical significance. Receiver operating characteristic (ROC) analysis indicated that circCCDC66 had a sensitivity of 79.41% for diagnosing CD, but it was unable to distinguish disease activity. A positive correlation was identified between circCCDC66 and Fc in patients with active CD (p = 0.034, rs= 0.517).Conclusion: These findings imply that circCCDC66 may contribute to CD pathology and hold potential as a non-invasive diagnostic marker, especially during remission. However, neither circCCDC66 nor AKT2 effectively distinguished disease activity. Further research is necessary to clarify their functional roles in CD.