When the Molecules Start Playing Chess, or How MicroRNAs Acquire Dualistic Activity During Cancer Progression

Genomic instability was found to be a major source of a chromosomal rearrangement resulting in multidimensional gene network reprogramming, providing survival benefits to cancer cells. One recently discovered phenomenon caused by these changes is the dualistic microRNA activity, converting tumor suppressor microRNAs into tumor promoting omcomiRs. Understanding mechanics of this dualism will reveal how far tumor progression could go. This chapter will discuss some aspects of the current knowledge and understanding of this side of oncogenesis.