Human squamous carcinoma cell invasion in organ-cultured skin

In a previous study we showed that normal human epidermal keratinocytes were capable of invading the dermis of organ cultured skin when the tissue was treated with an exogenous source of epithelial growth factors (Fligiel and Varani (1993) Invasion Metastasis, 13, 225–233). Here we examined human squamous carcinoma cells from three different tumors for ability to invade the dermis in the same model. Invasion occurred in 40–80% of the tissues, depending on the tumor line, and was observed with equal frequency under both growth factor-free conditions and in the presence of exogenous growth factors. These data demonstrate that malignant human epithelial cells have the capacity to invade the dermis of organ-cultured skin. Unlike normal keratinocytes, there appears to be no exogenous growth factor requirement for invasion by the malignant cells.