SALL4 promotes glycolysis and chromatin remodeling via modulating HP1α-Glut1 pathway

SALL4 has recently been identified to promote chemo-resistance in multiple types of cancer, but the underlying mechanism remains to be fully established. Open chromatin structure is important for DNA damage response (DDR) and DNA repair. Here, we demonstrate that SALL4 promotes open chromatin by destabilizing heterochromatin protein 1a (HP1a) by recruiting ubiquitin E3 ligase CUL4B to HP1 alpha. The silencing of SALL4 in cancer cells decreased the expression levels of Glut1 and inhibited glycolysis in cancer cells. The upregulation of HP1 alpha in human cancer cells suppressed open chromatin, glycolysis and Glut1 expression levels. Therefore, SALL4 promotes the expression of Glut1 and open chromatin through a HP1 alpha-dependent mechanism. Impaired DDR in SALL4-deficient human cancer cells can be rescued by the restored expression of Glut1, indicating the importance of HP1 alpha-Glut1 axis in SALL4-mediated DDR. These findings demonstrate that SALL4 could induce drug resistance by enhancing DDR and DNA repair through promoting glycolysis and subsequent chromatin remodeling.