Suppression of Myeloid cell leukemia-۱ gene expression by siRNA increases the susceptibility of acute myeloid leukemia cells to Etoposide

Introduction: Myeloid cell leukemia-۱(MCL-۱) gene has been shown to be overexpressed in myeloid leukemia cells (AML), which eventually lead to inhibition of apoptosis and cancer progression. On the other hand, studies have shown that the expression of these gene is increased in AML patients with Etoposide-treated. Therefore, the aim of this study was to target Mcl-۱ by small interference RNA (siRNA) and analyze its effects on Mcl-۱ expression, cell growth and sensitivity of the HL ۶۰ cells to Etoposide. Methods: The expression of Mcl-۱were measured using RT-qPCR and western blotting. The cytotoxic effects of Mcl-۱ siRNA (siMcl-۱) and etoposide were determined using trypan blue assay and MTT assay on their own and in combination with etoposide. Apoptosis was measured using ELISA cell death assay. Results: Transfection with siMcl-۱ significantly suppressed the expression of Mcl-۱mRNA and protein in a time dependent manner, resulting in strong growth inhibition and spontaneous apoptosis. Surprisingly, pretreatment with siMcl-۱ synergistically enhanced the cytotoxic effect of etoposide. Furthermore, Mcl-۱ down-regulation significantly increased apoptosis sensitivity to etoposide. No significant biological effects were observed with negative control siRNA treatment. Conclusions: Our results suggest that specific suppression of Mcl-۱ by siRNA can effectively induce apoptosis and overcome chemoresistance of leukemic cells. Therefore, siMcl-۱ may be a potent adjuvant in leukemia chemotherapy.

کلیدواژه ها:

MCL-۱ ، siRNA ، HL ۶۰ cells ، Etoposide