Bone marrow mesenchymal stem cells-derived exosomal microRNA-19b-1-5p reduces proliferation and raises apoptosis of bladder cancer cells via targeting ABL2

Background: Exosomes are involved in intercellular communication via specialized molecular cargo, such as microRNAs (miRNAs). However, the mechanisms underlying exosomal miR-19b-1-5p in bladder cancer remain largely unknown, thus, we aim to investigate the effect of exosomal miR-19b-1-5p on bladder cancer with the involvement of non-receptor protein tyrosine kinase Arg (ABL2). Methods: miR-19b-1-5p and ABL2 expression were tested in bladder cancer. miR-19b-1-5p inhibition/elevation assays were conducted to determine its role in bladder cancer. Exosomes were extracted from bone marrow mesenchymal stem cells (BMSCs). Exosomes and T24 cells were co-cultured to verify their function in biological characteristics of bladder cancer cells. Results: miR-19b-1-5p was down-regulated while ABL2 was upregulated in bladder cancer. Exosomal miR-19b-15p suppressed malignant behaviors of bladder cancer cells, and also inhibited tumor growth in vivo. Up-regulated ABL2 mitigated the effects of miR-19b-1-5p up-regulation on bladder cancer cells. Conclusion: BMSCs-derived exosomal miR-19b-1-5p suppresses bladder cancer growth via decreasing ABL2.