miRNA Profiles of Camptothecin-Sensitive and Resistant Jurkat T-Cells

MicroRNAs which are non-coding RNAs 19-25 nt in length regulate gene expression at post-transcriptional and translational stages. Although it is known that they play a role in critical processes such as development and differentiation of T cells, a major component of the immune system, the function of miRNAs in T cell apoptosis is unknown. This study has aimed to identify miRNAs’ involvement in camptothecin-induced T cell apoptosis in the Jurkat T cell leukemia cell line model. Following the enrichment of the apoptotic population by magnetic seperation, the negative and apoptotic fractions were profilled and compared according to the expression levels of microRNAs. Jurkat T Lymphocytes were treated with 8 µM camptothecin for 4 hours to keep the population in early apoptotic phase, confirmed by immunoflorescent labeling. Treated and untreated populations were subjected to magnetic cell sorting. Four subfractions were obtained as untreated antiapoptotic (JNN-Jurkat Negative Negative), untreated apoptotic-which are naturally apoptotic- (JNP-Jurkat Negative Positive), camptothecin-treated apoptotic (JAP-Jurkat Apoptotic Positive) and camptothecin-treated antiapoptotic (JAN-Jurkat Apoptotic Negative). JNP fraction was not used for further analysis because of insufficient number of cells. Total RNA was extracted from all of the samples samples having higher RNA Quality due to RIN were chosen for miRNA array analysis. 2 replicates of JNN, 3 replicates of JAP and JAN were subjected to array analysis. 3 replicates of JNN fraction were mixed in 2 replicates because array analysis was performed in 8 channels.