Establishment and characterization of fetal and maternal mesenchymal stem/stromal cell lines from the human term placenta.

Introduction: Human placental mesenchymal stem/stromal cells (MSC) are an attractive source of MSC with great therapeutic potential. However, primary MSC are difficult to study in vitro due to their limited lifespan and patient-to-patient variation.

Methods: Fetal and maternal MSC were prepared from cells of the chorionic and basal plates of the placenta, respectively. Fetal and maternal MSC were transduced with the human telomerase reverse transcriptase (hTERT). Conventional stem cell assays assessed the MSC characteristics of the cell lines. Functional assays for cell proliferation, cell migration and ability to form colonies in soft agar were used to assess the whether transduced cells retained properties of primary MSC.

Results: Fetal chorionic and maternal MSC were successfully transduced with hTERT to create the cell lines CMSC29 and DMSC23 respectively. The lifespans of CMSC29 and DMSC23 were extended in cell culture. Both cell lines retained important MSC characteristics including cell surface marker expression and multipotent differentiation potential. Neither of the cell lines was tumourigenic in vitro. Gene expression differences were observed between CMSC29 and DMSC23 cells and their corresponding parent, primary MSC. Both cell lines show similar migration potential to their corresponding primary, parent MSC.

Discussion: The data show that transduced MSC retained important functional properties of the primary MSC. There were gene expression and functional differences between cell lines CMSC29 and DMSC23 that reflect their different tissue microenvironments of the parent, primary MSC. CMSC29 and DMSC23 cell lines could be useful tools for optimisation and functional studies of MSC.