Human papillomavirus 16 E6/E7-immortalized human gingival keratinocytes with epithelial mesenchymal transition acquire increased expression of cIAP-1, Bclx and p27(Kip1).

Epithelial mesenchymal transition (EMT) has been implicated in neoplastic invasion and metastasis. We have previously generated six cell lines from human gingival mucosal keratinocytes immortalized by E6/E7 of human papillomavirus type 16. Ldk and NuB1 lines represented EMT phenotype and other four lines represented cobblestone non-EMT phenotype. These cell lines were utilized as model cells to determine whether inhibitors of apoptosis proteins and cell-cycle regulators were molecular players during EMT. EMT cells exhibited increased expression of vimentin, vascular endothelial growth factor (VEGF) receptor1 and the ability to form tubules on Matrigel as well as to grow anchorage independently. We found that EMT cells expressed significantly elevated levels of cIAP-1, Bclx and p27(kip) higher than non-EMT cells. These proteins could therefore be used as intrinsic indicators of EMT of human gingival keratinocytes.