Transcription profiling of human normal and RhoA immortal cells

Rho family small GTPases serve as molecular switches in the regulation of diverse cellular functions including actin cytoskeleton remodeling, cell migration, gene transcription, and cell proliferation. Importantly, Rho overexpression is frequently seen in many carcinomas. However, published studies have almost invariably utilized immortal or tumorigenic cell lines to study Rho GTPase functions and there are no studies on the potential of Rho small GTPase to overcome senescence checkpoints and induce preneoplastic transformation of human mammary epithelial cells (hMECs). We found that ectopic expression of wild-type RhoA as well as a constitutively-active RhoA mutant (G14V) in primary hMEC strains led to their immortalization and preneoplastic transformation. Significantly, RhoA-T37A mutant, known to be incapable of interacting with many well known Rho-effectors ,was also capable of immortalizing hMECs.Our results demonstrate that RhoA can induce the preneoplastic transformation of hMECs by altering multiple pathways linked cellular transformation and breast cancer. Through microarray analysis, we want to identify genes and pathways linked to RhoA induced hMECs immortalization. Experiment Overall Design: 4 samples, in triplicate analyses per sample.