| MicroRNAs are identified to take actively part in the development of different cancers. Reduced expression of tumor suppressor miRNAs leads to cancer cell development, so restoring the expression of these miRNAs can be an appropriate treatment
option for cancer. Due to the heterogeneity of cancer cells, single-drug therapy often results in drug resistance. Therefore,
the combination of chemotherapy with miRNA can be a powerful strategy for cancer treatment. In the current investigation,
miR-34a mimic, and negative control were purchased and transfected using jetPEI reagents. Then the synergic effects of
miR-34a in combination with doxorubicin were investigated on cell death of acute T-cell lymphoblastic leukemia Jurkat
cell line, as well as the expression of some genes including Caspase-3, Bcl-2, and p53 which are involved in apoptosis. Our
outcomes showed that this combination remarkably reduced the expression of the Bcl-2 gene, the target gene of miR-34a.
According to the results of the MTT assay, the survival rate was significantly decreased compared to the untreated cells.
Results of the flow cytometry assay and DAPI staining demonstrated an increased apoptosis rate of Jurkat cells in combination
therapy. Moreover, cell cycle arrest was observed at the G2/M phase in cells that were treated with miR-34a/doxorubicin.
Most importantly, we showed that the transfection of the Jurkat cells with miR-34a increased the sensitivity of these cells
to doxorubicin. Furthermore, the combination of miR-34a and doxorubicin drug effectively increased apoptosis of treated
cells. Therefore, this method can be used as an impressive treatment for T-ALL. |