Figure 2.

Two-dimensional hierarchical cluster analysis of gene expression profiles following treatments with anticancer drugs. PC-3, DU-145, and MDA-MB-231 cells were treated for 24 h at doses described in Table 1. Unsupervised hierarchical clustering (GeneMaths software) was applied to the list of modulated genes as described in Materials and Methods. Increases in mRNA expression are indicated by shades of red while decreases are shown by shades of green. Cluster A: genes involved in the stress/apoptosis responses in PC-3 and MDA-MB-231; this cluster is divided into clusters A₁ and A₂ in DU-145. Cluster B₁: spindle inhibitors biomarkers; genes involved in cell cycle progression and mitosis. Cluster B₂: spindle inhibitors biomarkers; genes involved in replication process. Cluster C₁: topoisomerase inhibitors biomarkers; genes involved in response to interferon. Cluster C₂: doxorubicin biomarkers; doxorubicin-induced genes.