ObjectiveTo study the synergistic effect of NKX6.1 and PDX1 in inducing differentiation of fetal liver-derived mesenchymal stem cells(FL-MSCs) into the pancreatic B cells and to explore the underlying mechanisms, so as to obtain enough islet-like body for transplantation. MethodsRecombinant adenovirus vector harboring both PDX1 and NKX6.1 genes was constructed, and the vector was used to infect FL-MSCs. Then a series of cytokines were used to induce the differentiation of infected FL-MSCs into pancreatic B cells. The expressions of PDX1, NKX6.1 gene, transcription factors NGN3, NeuroD1/Beta2, MafA as well as C-peptide were examined. ResultsPDX1 and NKX6.1 were detected in FL-MSCs cells 24 h after infection; cells began to express NGN3, NeuroD1, and MafA and stably expressed pancreatic B cell related factors including insulin after induction.The expression of these molecules was in a certain order. ConclusionPDX1, NKX6.1 combined with a series of cytokines can effectively induce FL-MSCs to differentiate into pancreatic islet B cells in vitro, which might be through activation of transcription factors NGN3, NeuroD1, and MafA in turn, inducing FL-MSCs to differentiate towards endocrine precursor cells,B endocrine precursor cells and B cells in turn.