Human Ppithelial cell line immortalized by Ad12-SV40 hybrid virus was transfected with plasmid containing HPV-16 via calcium-phosphate method.
Subsequently, 8 clonal cell lines were obtained after G418 selection. Among these clonal cells, clonal cell-4(C-4) and clonal cell-6(G-6) showed increases of tumorigenic cellular properties such as saturation density, soft agar colony formation and cell aggregation. Morphological alteration such as appearane of foci was observed on these two clones after passage 6 and 7(50 to 55 days after transfection).
When clonal cells and control cells were treated with MNNG(0.Olug/ml), both C-4 and C-6 showed increases of tumorigenic cellular properties and the level of increase was much more elevated as compared to clonal cells prior to MNNG treatment. Appearance of foci formation was observed in C-4 and C-6 after passage-6. After passage-8, control cells and all clonal cells showed morphological alterations. It seems that treatment of cells containing HPV-16 DNA with MNNG increases tumorigenic properties of the cells and expedite morphological transformations.
Significant increases of fibronectin and its RNA level were observed on the morphologically altered clonal cell lines(C-4 and C-6), as compared to clonal cells. Considering that fibronectin plays important roles in spreading, adhesion and differentiation of tumor cells, increase of fibronection in the transformed cells can be sued as a valuable biological
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