We studied the expression profile of SV40 cells cultured in the medium with or without serum to address the immortalization method which keeps original nature as so far. The whole expression pattern profiling revealed that immortalized corneal epithelial cells with SV40 showed a distinct expression pattern from wild-type cells regardless of the presence or absence of serum. In contrast, corneal epithelial cells with combinatorial expression of mutant cyclin dependent kinase 4, cyclin d1, and telomerase transcriptase  (K4DT) showed an expression pattern relatively closer to that of wild-type cells.  "The transcriptome of wild-type and immortalized corneal epithelial cells" by Furuya et al has just accepted to Scientific Data.

This study showed the three-dimensional PCA analysis, which quickly identifies the expression patterns of whole genes with a movie. However, due to the Figure in Scientific Data limitation, we can only write the web link to the Figshare.  However, we would like to show the actual 3D movie of wild type, SV40 immortalized (serum or no cultured serum condition), and K4DT corneal epithelial cells.  As you can see, SV40 is most distant in the movie regardless of serum or no serum condition.  The K4DT cell, which is the newest immortalization, showed most closest to wild type.  Although even in K4DT, there is a difference from wild type.  However, the distance from SV40 to wild type becomes shorter when compared from wild type to K4DT.  This data is the molecular evidence that immortalization technology showed remarkable progress in cell biology.  Please enjoy the movie.