Next Generation Sequencing to study Thalidomide mechanism in Cutaneous Lupus

Thalidomide has been shown to be effective in patients with refractory cutaneous lupus erythematosus (CLE). However, its use is still limited by its potential severe side-effects. We conducted an RNA-sequencing study using CLE skin biopsies before and after thalidomide treatment to discover its mechanism of action. Methods: Total mRNA from skin biopsies from 10 CLE patient have been processed by RNA-seq in duplicate using Illumina Hiseq 2000 sequencing platform version 3. Application was stranded mRNA-Seq, paired-end and read length was 75bp. The sequence reads that passed quality filters were analyzed at the transcript isoform level using STAR program, RSEM program and DESeq2. Mapping was done with STAR (version 2.5.2a), quantification by RSEM (1.2.28) and differential analysis by DESeq. Results: Using an optimized data analysis workflow, we mapped about 30 million sequence reads per sample to human genome (hs37d5). Average un-mapped was between 11,40-7,05 %, average unique was 80.48-76,62% and average alignment insert size was 170,00-155,00 in the 20 samples. Conclusions: Plausibles mechanisms of action for thalidomide in lupus cutaneous were discovered using this study; however, in vitro and in vivo experiments would be performed to demostrate them. Total skin mRNA profiles pre and post-treatment of thalidomide (3weeks between them).