Yin Yang 1 regulation of tumor cell resistance to chemotherapeutic drugs

Although many cancer patients initially respond to current therapies, unfortunately, the response of many patients is short lived, since the tumor cell develops resistance to the chemotherapeutic drugs. The subset of cancer patients who develops cross-resistance to distinct therapeutics usually succumbs to death. Therefore delineating the underlying molecular mechanisms of resistance of various cancers and identifying molecular targets for intervention are the current focus of research investigations. One approach to investigate cancer resistance has been to identify pathways that regulate resistance and develop means to disrupt these pathways to avoid resistance and sensitize the resistant tumor cells to cell death by chemotherapeutic drugs. Yin Yang 1 (YY1), a dual function transcription factor, is known to regulate transcriptional activation and repression of many genes associated with multiple cellular processes including chemoresistance. Due to its role in processes that are linked to malignant transformation upon its own deregulation, YY1 has been implicated as a major driver of many cancers. This chapter describes different mechanisms in which YY1 is playing a very important role in the resistance of cancer cells. The better understanding of these mechanisms allows us to propose novel drugs, and specific treatment strategies may be developed using this transcription factor YY1 as a target for cancer therapy.