Gene expression profile of breast cancer cells.

We compared the gene expression profile of 26 breast cancer cell lines to identify variations associated with different phenotypes and molecular subtype. The panel includes 13 estrogen receptor negative (ER-) and 13 ER+ cell lines. Four of the ER- cell lines and 5 of the ER+ cell lines are HER2 positive. We have used 2-color gene expression arrays for two separate studies. The one described here compares the intensities of one color channel across 26 cell lines, as normalized signal intensities. The second color channel is not analyzed here and will be used in a separate study.