Abstract: Objective To study the mechanism of anti-keratin autoantibodies (AK auto Ab) inhibiting the keratinocytes proliferation. Methods Keratinocytes from normal human skin and squamous cell carcinoma were cultured, then treated with AK auto Ab in different doses. MTT and immunohistochemical technologies were applied to test the proteins related to proliferation and apoptosis. Results AK could inhibit the proliferation of these two kinds of cells with a dose related effect. AK auto Ab could promote the expression of p53,c-myc, and inhibited the expression of PCNA. Conclusions The results indicate that AK auto Ab plays an important role in the proliferation of keratinocytes both from normal skin and from SCC.

Key words: Squamous cell carcinoma, Apoptosis, Autoantibodies, Keratinocytes