Low oxygen stimulates proliferation of fibroblasts seeded as single cells

In standard tissue culture conditions (20% oxygen), single human dermal fibroblasts (one cell per well) do not proliferate. We now report that low oxygen tension is a potent stimulus for the proliferation and expansion of human adult and neonatal dermal fibroblasts seeded as single cells. This preferential single-cell proliferation in low oxygen is shown to be also a feature of human lung and dermal rodent fibroblasts, but not of human fibrosarcoma and immortalized 3T3 cells, which proliferate without difficulty in standard oxygen conditions. It is suggested that single-cell proliferation and its dramatic stimulation in low oxygen may represent a fundamental biologic process with an opportunity to better understand mammalian cell growth regulation.