Purpose: Bone marrow mesenchymal stem cells(MSCs)could be differentiated into neuron-like cells in vitro,but whether the differentiated cells could establish an effective neural signal transduction network is unclear.Neural signal transduction is mainly based on the polarization of neurons.RARD6 is the main composition protein of cell polarization compound PARD6/PARD3/PKC.So we aimed to investigate the expression of PARD6 during the process of MSCs differentiated into neuron-like cell and observe the polarization of neuron-like cell differentiated from MSCs.In addition,we screened a microRNA family let-7 by bioinformatics,which might regulate the expression of PARD6.Further,we explored whether let-7 was involved in the differentiation of MSCs into neuron-like cells by regulating the expression of PARD6.