New insights into the interplay between MALAT1 and miRNA-155 to unravel potential diagnostic and prognostic biomarkers of Behçet's disease.

The current study was deployed to evaluate the role of metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) and miR-155, along with the inflammatory markers, TNFα and IL-6, and the adhesion molecule, cluster of differentiation 106 (CD106), in Behçet's disease (BD) pathogenesis. The study also assessed MALAT1/miR-155 as promising diagnostic and prognostic biomarkers for BD. The current retrospective case-control study included 74 Egyptian BD patients and 50 age and sex-matched controls. Blood samples were collected, and then, serum samples were separated for further biochemical and molecular investigations. The gene expression of MALAT1 and miR-155 was measured using qRT-PCR, whereas the levels of TNFα, IL-6, and CD106 were estimated using ELISA technique. MALAT1 was significantly downregulated, whereas miR-155 was upregulated among BD patients, compared with control subjects. Levels of TNFα, IL-6, and CD106 were elevated in BD patients. Further downregulation in MALAT1 together with upregulation of miR-155 was observed in active BD patients, relative to the inactive group. Receiver-operating-characteristic analysis revealed that MALAT1 and miR-155 could discriminate BD patients from controls, on the one hand, and active from inactive BD patients, on the other hand. MALAT1 was negatively correlated with TNFα, IL-6, and CD106, while miR-155 was positively correlated with them. Logistic regression analyses demonstrated miR-155 as a significant independent predictor of BD susceptibility, and MALAT1 as an independent negative predictor of BD activity. For the first time, the current research enlightens the role of MALAT1 and miR-155 in BD pathogenesis via impacting IL-6/TNF-α/CD-106 signaling. As well, MALAT1 and miR-155 could be regarded as novel non-invasive biomarkers that may improve BD diagnosis and prognosis. Key Points •MALAT1/miR-155 exerts potential role in Behçet's disease. •MALAT1/miR-155 are promising biomarkers for Behçet's disease. •MALAT1/miR-155 targets IL-6/TNF-α/CD-106 signaling.