Chromosomal number aberrations and transformation in adult mouse retinal stem cells in vitro.
OBJECTIVE
The potential of stem cells (SCs) as a source for cell-based therapy on a wide range of degenerative diseases and damaged tissues such as retinal degeneration has been recognized. Generation of a high number of retinal stem cells (RSCs) in vitro would thus be beneficial for transplantation in the retina. However, as cells in prolonged cultivation may be unstable and thus have a risk of transformation, it is important to assess the stability of these cells.


METHODS
Chromosomal aberrations were analyzed in mouse RSC lines isolated from adult and from postnatal day (PN)1 mouse retinas. Moreover, selected cell lines were tested for anchorage-dependent proliferation, and SCs were transplanted into immunocompromised mice to assess the possibility of transformation.


RESULTS
Marked aneuploidy occurred in all adult cell lines, albeit to different degrees, and neonatal RSCs were the most stable and displayed a normal karyotype until at least passage 9. Of interest, the level of aneuploidy of adult RSCs did not necessarily correlate with cell transformation. Only the adult RSC lines passaged for longer periods and with a higher dilution ratio underwent transformation. Furthermore, we identified several cell cycle proteins that might support the continuous proliferation and transformation of the cells.


CONCLUSIONS
Adult RSCs rapidly accumulated severe chromosomal aberrations during cultivation, which led to cell transformation in some cell lines. The culture condition plays an important role in supporting the selection and growth of transformed cells.
Djojosubroto
Meta
M
Unit of Gene Therapy and Stem Cell Biology, Department of Ophthalmology, Jules-Gonin Eye Hospital, Lausanne, Switzerland.
Bollotte
Frederic
F
Wirapati
Pratyaksha
P
Radtke
Freddy
F
Stamenkovic
Ivan
I
Arsenijevic
Yvan
Y
D000818:Animals; D000831:Animals, Newborn; D015153:Blotting, Western; D018797:Cell Cycle Proteins / Q000378:metabolism; D002454:Cell Differentiation; D002460:Cell Line; D049109:Cell Proliferation; D002471:Cell Transformation, Neoplastic / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D002869:Chromosome Aberrations; D007381:Intermediate Filament Proteins / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D016688:Mice, Inbred NOD; D008819:Mice, Nude; D009419:Nerve Tissue Proteins / Q000378:metabolism; D064231:Nestin; D009687:Nuclear Proteins / Q000378:metabolism; D063150:Polycomb Repressive Complex 1; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism; D012160:Retina / Q000473:pathology*; D019572:Retinal Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D033581:Stem Cell Transplantation; D013234:Stem Cells / Q000378:metabolism / Q000473:pathology*
C489421:Bmi1 protein, mouse; D018797:Cell Cycle Proteins; D007381:Intermediate Filament Proteins; D009419:Nerve Tissue Proteins; C577485:Nes protein, mouse; D064231:Nestin; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; D012097:Repressor Proteins; D063150:Polycomb Repressive Complex 1