P364 New insights into the molecular mechanisms of thalidomide in paediatric inflammatory bowel disease patients
M. Lucafò1, M. Bramuzzo2, L. Pugnetti3, M. Gerdol4, S. Greco4, M. Paci5, D. Curci6, M. Nonnis4, S. Renzo5, P. Lionetti5, A. Tommasini1, G. Decorti7, G. Stocco4
1Institute for Maternal Health - IRCCS ‘Burlo Garofolo’, Advanced in Translational Diagnostics Laboratory, Trieste, Italy, 2Institute for Maternal Health - IRCCS ‘Burlo Garofolo’, Gastroenterology- Digestive Endoscopy and Clinical Nutrition Unit, Trieste, Italy, 3Department of Medical-Surgical and Health Sciences, PhD School in Science of Reproduction and Development- University of Trieste- Trieste- Italy, Trieste, Italy, 4Department of Life Sciences, University of Trieste - Trieste - Italy, Trieste, Italy, 5Gastroenterology Unit, Anna Meyer Children’s Hospital -Florence- Italy, Florence, Italy, 6Department of Medical-Surgical and Health Sciences, PhD School in Science of Reproduction and Development, University of Trieste - Trieste - Italy, Trieste, Italy, 7Department of Medical-Surgical and Health Sciences, University of Trieste - Trieste - Italy, Trieste, Italy
Background
Thalidomide is an effective drug in children with inflammatory bowel disease (IBD) refractory to standard treatments, however, its use is often limited by its safety profile, in particular for the risk of teratogenicity and peripheral neuropathy. Multiple hypotheses exist to explain the molecular mechanism of thalidomide action but no data have been published on IBD patients. To identify determinants of thalidomide action in paediatric IBD, high-throughput microRNA (miRNA) and messenger RNAs (mRNA) profiles during treatment were analysed.
Methods
IBD patients responsive to thalidomide were enrolled. miRNA and mRNA profiles from peripheral blood obtained before and after 12 weeks of treatment were determined using next-generation sequencing. Differentially expressed genes were identified by fold change from the general linear model. In order to detect the potentially altered pathways, the hypergeometric test based on gene ontology annotations was used. The identification of putative mRNA targets of thalidomide sensitive miRNAs was performed by Targetscan database.
Results
Ten IBD paediatric patients (mean age 13.1 years, 6 males) were enrolled. Sequencing analysis identified 10 miRNAs (3 downregulated) and 252 mRNAs (76 downregulated) deregulated after treatment. Five upregulated miRNAs could putatively recognise the 3′UTR of several Hox genes, a group of transcription factors that play important roles in the development of structures such as limbs, lungs and nervous system. The hypergeometric test highlighted the altered pathways involved in inflammatory response, regulation of immune system, prostaglandin receptor activity and G protein-coupled receptor signalling. Among the 10 miRNAs deregulated by thalidomide, six could putatively regulate the differentially expressed mRNAs resulting from the analyses.
Conclusion
Thalidomide induces specific gene expression alterations, which could help to elucidate its molecular mechanism in paediatric IBD patients. miRNA results may suggest new molecular targets involved in the teratogenic effects of this drug. Moreover, mRNA profiles indicate a strong involvement of adenylate cyclase-modulating G protein-coupled receptor signalling in the thalidomide mechanism of action.