[Retention of biological features in human placental mesenchymal stem cells transfected by multidrug resistance gene].

Objective: To transfer multidrug resistance gene (mdr1) into human placental mesenchymal stem cells (P-MSCs) by retroviral vector and assess the effects of mdr1 gene transduction upon biological features of P-MSCs.

Methods: Human P-MSCs were isolated from trypsin-digested term placentas and then transduced by reconstructed retroviral vector containing mdr1 gene and green fluorescent protein (GFP) reporter gene. Flow cytometric analysis was employed to determine the immunophenotypes of transfected P-MSCs. And the proliferation and cell cycle were detected by methyl thiazolyl tetrazolium and propidium iodide staining. Ultrastructures of transfected P-MSCs were observed and different induction conditions used to direct the cells to differentiate into adipocytes and osteoblasts.

Results: The transfected P-MSCs still expressed stem cell markers such as CD29, CD44 and CD73. The mean cumulative time of population doubling was 23.9 hours. The cellular cycle retained the proliferative characterization of stem cells. Ultrastructural features of transfected P-MSCs included increased surface microvilli, abundant mitochondria and slightly swollen rough endoplasmic reticulum. Furthermore these transfected cells demonstrated osteogenic and adipogenic differentiation potentials under appropriate conditions.

Conclusion: The mdr1 gene transduction by retroviral vector in vitro has no significant effect upon biological characteristics of P-MSCs. It might provide experimental references for the application of P-MSCs in high-dose tumor chemotherapy.