Cell lines: Valuable tools or useless artifacts

Abstract

Cell lines are often used in place of primary cells to study biological processes. However, care must be taken when interpreting the results as cell lines do not always accurately replicate the primary cells. In this article, we will briefly talk about advantages and disadvantages of cell lines and then discuss results using the mouse Sertoli cell line, MSC-1, compared with primary mouse Sertoli cells. MSC-1 cells resemble Sertoli cells morphologically and possess several biochemical markers associated with Sertoli cells. Studies have demonstrated that the function and regulation of retinoic acid receptor α (RARα) is similar between MSC-1 and rat Sertoli cells. However, MSC-1 cells lack some of the immune privilege properties associated with primary Sertoli cells, including survival in animals with a fully functional immune system. Therefore, it has to be kept in mind that cell lines do not behave identically with primary cells and should not be used to replace primary cells. In order to strengthen the findings, key control experiments using primary cells should always be performed.

Figure 1. FSHr mRNA expression and survival of MSC-1 and MSC-1FSHr cells as allografts. MSC-1 cells stably transfected with rat FSHr cDNA were obtained from Dr. Griswold (Washington State University, Pullman, WA). MSC-1FSHr cells were maintained and cultured essentially the same as MSC-1 cells with the exception of the addition of 250 mg/ml G418 (Invitrogen, Carlsbad, CA). A and B) RT-PCR was performed for FSHr (A), Lanes 2 and 3; Primers-For 5′CCA TTG TGT CCT CAT CAA GC, Rev 5′CAT GGA AGT TGT GGG TAG CG) or cyclophilin (B), Lanes 2 and 3; Primers-For 5′CCC ACC GTG TTC TTC GAC, Rev 5′ATC TTC TTG CTG GTC TTG CC) with RNA isolated from MSC-1FSHr (A and B, Lane 2) or MSC-1 cells (A and B, Lane 3). Lane 1 (A and B) is 1 kb Plus DNA Ladder (Invitrogen). (C and D) MSC-1 (D) or MSC-1FSHr (C) cells were cultured as aggregated for 48 h. Aggregates were fixed, dispersed in agar, embedded in paraffin, sectioned and immunostained for large T antigen (brown color) and hematoxylin (blue color). (E-H) Four million of these aggregated cells were transplanted under the kidney capsule of naïve (E and F) and diabetic (G and H) BALB/c mice. The grafts were collected at day 20 post-transplantation, and tissue sections were immunostained for MSC-1 cell marker, large T antigen (brown color, E-H). All sections were counterstained with hematoxylin (blue color). A dotted line separates the kidney from the graft. K, kidney; Arrow, large T antigen positive cells. Care and maintenance of animals described in (E-H) was performed in accordance with the Institute for Laboratory Animal Research Care and Use of Laboratory Animals, and Texas Tech University Institutional Animal Care and Use Committee-approved protocols.