Exosomes from miR-141-Inhibitor-Modified Bone Marrow Stem Cells Restrain the Proliferation of Prostate Cancer Cells

Abstract

miR-141 is highly expressed in prostate cancer. miR-141 can down-regulate PTEN to enhance Akt expression, thereby facilitating the malignant features of cells. Bone marrow stem cells (BMSCs) are one type of promising therapeutic carrier for the exosomes. This study assessed the effect of exosomes originating from the miR-141-inhibitor-modified BMSCs on prostate cancer cells. For in vitro experiment, a prostate cancer cell line (DU145 cells) was employed and when they reach a logarithmic growth phase, they were co-cultured with BMSCs and then assigned into miR-141 down group, miR-141 up group, NC group and control group followed by analysis of miR-141 expression by quantitative-PCR, cell proliferation by MTT assay, cell cycle and apoptosis by flow cytometry, and P13K/Akt/mTOR pathway-related proteins expression by western blotting. The exosomes originating from the miR-141-inhibitor-modified BMSCs decreased miR-141 expression, restrained cell proliferation, increased cell proportions in G0/G1 and G2 phases, while decreased cell proportions in S phase. Control group and miR-141 down group exhibited weak expression of PI3K/Akt/mTOR signal proteins, which included p-mTOR, p-P70S6K, p-4E-BP1, p-Akt and p-PTEN. In conclusion, exosomes from the miR-141-inhibitor-modified BMSCs can restrain prostate cancer cell proliferation and increase apoptosis possibly through targeting PTEN to modulate the P13K/Akt/mTOR signal transduction pathway.