Deregulation of ZIC Family Members in Oncogenesis.

In the last decade, the amount of investigations on the involvement of ZIC genes in the cancer field have exponentially expanded. In most cancer types, promoter methylation leads to silenced ZIC family members, but specific subsets of patients clearly show increased expression of one or head-to-head located ZIC genes in the respective tumor tissue. It is unclear at this stage how these transcription factors contribute to tumorigenesis, but the potential implications in pathways that are most frequently mutated in cancer such as the canonical Wnt, TGF-beta, and STAT-3 pathway are evident. By exploring well-established developmental models, researchers were able to position ZIC genes not only as classical transcription factors but also as cofactors of chromatin remodeling complexes that are crucial for maintenance of the cell but also during differentiation and maturation of ZIC-expressing tissues in vivo. The translation of this obtained evidence to the cancer field will be challenging but will indisputably lead to a better understanding how the factors can contribute to the tumor development in the given subsets of patients.