Determination of miRNA expression levels on sickle cell anemia cases by RT-PCR

MicroRNAs are short non-coding RNAs of 18-25 nucleotides in length that regulate gene expression via mRNA degradation or translational inhibition.1,872 human miRNA types have been identified so far and they have used as diagnosis and prognosis biomarker in many human diseases. It was found in studies that miRNAs take part in regulating hematopoiesis and hematopoietic cell differentiation. Abnormal hemoglobins are the most common hereditary blood disorder in the World. Sickle cell trait results in substitution of glutamic acid by valine at amino acid position 6 in β globin chains of Hb A. It is observed in some cases with sickle cell anemia that the level of Hb F has increased and the clinical course of these cases found to be milder, accordingly. In our study, the expression levels of leukocyte miRNAs of subjects with sickle cell anemia having high and normal HbF levels and healthy subjects were determined by RT-PCR methodology. Mann-Whitney U test were used to compare miRNA expression levels between groups and p<0.05 value were considered statistically significant. Sensitivity, specificity and AUC for leukocyte miRNAs expression levels were determined using ROC analysis. In this study, while let7 a, let7c, let7d, let7f, miR-144, miR-320a, miR-320b and miR-451a were observed to be over expressed in sickle cell anemia compared to healthy subjects, the opposite is true for miR-29a and miR-141 expressions. We determined that miR-96 is not expressed in leukocyte cells and miR-181a and let7e expression levels are not significantly different between two groups. Furthermore, statistically significant increase in the expression levels of miR-144 was observed in the sickle cell anemia subjects with Hb F levels <3% compared to Hb F levels >9%. According to ROC curve analysis elevated miR-451a expression may be considered to have prognostic value for sickle cell anemia.