RESUMO
The major hemoglobin in the fetus is hemoglobin F [alpha2gamma2], whereas in adult humans, hemoglobin A [alpha2beta2] is predominately expressed. Several studies have indicated that expression of the HbF subunit gamma-globin might be regulated post-transcriptionally. This could be done by small non-coding RNAs called microRNAs which target mRNAs in a sequence-specific manner and lead to translational repression or mRNA decay. The aim of this study is to evaluate the effect of miR-26b up-regulation on gamma-globin gene expression in K-562 cell line. These cells were grown in RPMI 1640 and pre miR-26b and were transfected within K-562 cell line using lentiviral vector. After RNA extraction and cDNA synthesis in selected days, miRNA up-regulation was confirmed by miRNA real time PCR and then gamma and beta chain and GATA-1 expression were investigated by RT and QRT-PCR. The viability of cells before transfection was 90%. Three and 7 days after transfection, through the use of relative Q-PCR, the gamma chain expression increased 3.7, 6.8 and 3.8 folds and GATA-1 expression increased 2.1, 6.0 and 8.0 in comparison with untransfected cells. The data suggest that miR-26b can be involved in the increase of gamma-globin gene expression in K-562 cell line. We suggest that miR-26b may be a significant therapeutic target for increasing HbF levels in patients with sickle cell disease and beta-thalassemia