YY1 and tumor metastasis regulation

Tumor metastasis is a prominent feature of cancer and poses challenges to the complete eradication of tumors. Tumor metastasis requires tumor cells to develop characteristics that enable them to overcome the systemic barriers and stress encountered during the metastatic processes. Metastasis is a complex process involving various steps and signaling pathways. It is initiated by the epithelial-mesenchymal transition (EMT), which is followed by breakdown of the basal lamina, entry into and travel through the circulation, survival in the circulation system, and finally metastatic colonization at a new site. Metastasis is also supported by other tumor characteristics such as tumor angiogenesis. Yin Yang 1 (YY1) is a ubiquitously expressed zinc-finger protein that is highly expressed in metastatic primary tumor tissues with poor prognosis. The direct and indirect roles of YY1 in modulating an extensive number of genes have been previously reported, including its regulation of prominent genes essential in EMT, metastatic colonization, tumor angiogenesis, and other processes favoring tumor metastasis. Therefore understanding the multifaceted molecular role of YY1 in tumor metastasis is a feasible approach for designing YY1-targeted therapies combating tumor metastasis. Here, we summarize the roles of YY1 in the various processes of tumor metastasis.