Induction of Apoptosis in the U937 Cell Line Co-cultured with Adipose-derived Stem Cells Secreting Bone Morphogenetic Protein-4

Transforming growth factor-beta (TGF-β) plays a significant role in tumorigenesis. MiR-181b is a multifunctional miRNA involved in numerous cellular processes, such as cell fate and cell invasion. This study aimed to examine whether the co-culture of adipose-derived stem cells (ADSCs), highly expressing bone morphogenetic protein-4, with the U937 cell line, which is a human myeloid leukemia cell line, is able to induce cell death in this cancer cell line, considering the potential ability of ADSCs to migrate from tumor sites. Cell surface markers, namely CD73 and CD105, were analyzed to verify the identity of mesenchymal stem cells isolated from adipose tissue. Besides, the osteogenic and adipogenic differentiation potentials of ADSCs were evaluated. The induction of cell death and apoptosis in the U937 cell line was assessed using MTT and annexin V/ PI assays, respectively. The expression levels of miR-181 and TGF-b were determined in the co-culture system using real-time PCR. The results of MTT and annexin V/ PI assays showed that BMP4-expressing ADSCs could inhibit cell viability and induce apoptosis in U937 cells in the co-culture system. The co-culture of ADSCs, highly expressing BMP-4, with the U937 cell line led to the downregulation of miR-181 and TGF-β genes in the human cancer cell line. ADSCs may further be studied as a candidate for the treatment of hematological cancers.