preadipocyte 3T3-L1 cells question? - (Sep/09/2009 )

I use preadipocyte 3T3-L1 cells for differenating mature adipocyte.
I know several passaging later, the preadipocyte 3T3-L1 cells failed to differenate into mature adipocyte.
Now I use virus infecting preadipocyte 3T3-L1 cells and select them with puromycin and get overexpressing a certain gene in 3T3-L1 cell clones.
I can use this overexpression cell lines for differenating into mature adipocyte.
But I want to know, whether after several passaging this cells, this overexpression cell line would fail to differenate into mature adipocyte.

I would guess so.

If WT 3T3-L1 fail to differentiate after several passages, the overexpressing cell-line will do the same, I guess.