High mobility group A-interacting proteins in cancer: focus on chromobox protein homolog 7, homeodomain interacting protein kinase 2 and PATZ

The High Mobility Group A (HMGA) proteins, a family of DNA architectural factors, by interacting with different proteins play crucial roles in neoplastic transformation of a wide range of tissues. Therefore, the search for HMGA-interacting partners was carried out by several laboratories in order to investigate the mechanisms underlying HMGA-dependent tumorigenesis. Three of the several HMGA-binding proteins are discussed in this review. These are the Chromobox family protein (chromobox protein homolog 7, CBX7), the homeodomain interacting protein kinase 2 (HIPK2) and the POZ/domain and Kruppel zinc finger family member, PATZ. All of them play a critical role in tumorigenesis, and may also be independent markers of cancer. Their activities are linked to cell cycle, apoptosis and senescence. In this review, we discuss the properties of each protein, including their effect on HMGA1 functions, and propose a model accounting for how their activities might be coordinated.