2. Division of Laboratories of CEMO, National Cancer Institute, Rio de Janeiro, Brazil.
The importance of Kaiso, Wnt5, Wnt11 and PcG proteins in tumorigenesis has been widely discussed in the scientific literature, in recent years. However, until now, there has been no exploration of the relationship of these sets of proteins and their meaning in vital processes of embryogenesis such as gastrulation or events that trigger cancer. In this paper, we characterize an independent transcriptional regulation of repression by Suz12 on Kaiso expression. The functional block of Suz12 by small interfering RNA produced an almost complete depletion of Kaiso expression in K562 cells. We suggest a regulatory loop that could involve a positive regulation of Suz12 on Kaiso and Wnt5a/Wnt11 on Suz12, and also, a negative regulation of Kaiso on Wnt11 establishing an important regulatory feedback to the normal state of the cell. The rupture of that regulatory balance might result in the tumor establishment. The close relation of Suz12 and non-canonical pathways of Wnt may provoke significant implications for future therapeutic strategies in chronic myeloid leukemia.
Keywords: Polycomb group proteins, kaiso, chronic myeloid leukemia, K562 cells