Expression of membrane glycoproteins in normal keratinocytes and squamous carcinoma cell lines

Con A acceptor glycoproteins were analyzed by 2D-PAGE and 125I-Con A overlay in three squamous carcinoma cell lines and compared with those in the simian virus (SV40)-transformed keratinocyte cell line SVK-14 and in normal keratinocytes. The majority of the glycoproteins identified by this technique were expressed at similar levels in all of the cells examined, independent of the culture conditions used. A cell surface glycoprotein gp34 (MW 34 kDa, pI 5.1) was increased in the tumor cells compared with normal keratinocytes and expression varied with the culture density. Another glycoprotein, gp21 (MW 21 kDa, pI 6.3), was found to be increased in expression in normal keratinocytes and stratified hyperconfluent cultures of squamous carcinoma cell lines. This paper describes the potential of this technique to identify membrane glycoproteins which may be expressed as a function of proliferation or differentiation.