Growth Inhibition of Primary Keratinocytes Following Transduction with a Novel TGFbeta-1 Containing Retrovirus

Growth and migration of keratinocytes are known to be affected by the addition of exogenous cytokines, such as TGFbeta-1, to culture media. We have developed a retroviral vector, LNTbeta-1, that confers constitutive expression of human TGFbeta-1 to transduced cells. Keratinocytes were exposed to retroviral particles generated in serum-free media, and infected cells were selected for with Geneticin. Transduced keratinocytes remained in culture as single cells instead of a normally grouped growth pattern. While these transduced keratinocytes survived in culture for several weeks, they did not proliferate and seemed arrested in their growth. Keratinocytes transduced with retrovirus not containing the TGFbeta-1 gene appeared normal in their growth pattern. These findings indicate that high-level endogenous expression of TGFbeta-1 in keratinocytes can at least inhibit, and possibly arrest, growth.