3-Dimensional microarray analysis of estrogen signal-related genes in breast cancer tissues.

Background: Expression analysis of estrogen response genes (ERGs) may help to predict the effectiveness of endocrine therapies in breast cancer patients. We produced a custom-made, 3-dimensional microarray system (3DMS), using previously identified ERGs, and analyzed expression of ERGs on breast cancer tissues.

Materials And Methods: aRNA was synthesized from 27 breast cancer tumors. The aRNAs were applied to the infrastructure of a 3DMS with spotted cDNA probes to 36 ERGs. Data were analyzed by cluster analysis.

Results: All 27 specimens were classified clearly into one of two clusters based on whether the ERGs were up or down regulated. These groups correlated with high expression of ER (P<0.05) and Her2 (P<0.05). In some cases, ERG expressions were low even though the tumor was ER positive.

Conclusion: 3DMS may be useful for accurately predicting prognosis and whether endocrine therapies targeting the ER would be effective in an individual breast cancer patient.