Tumor

By Christina Towers, PhD.

By Jamshed Arslan Pharm.D.

By Christina Towers, PhD.

Hypoxia is a common feature of most tumors and is a product of rapid cell growth and poor vascularization¹. When oxygen availability is low in the tumor environment, the hypoxia inducing transcription factors (HIFs) regulate a variety of signaling programs that can affect the balance between tumor cell apoptosis² and autophagy³.  In normoxia, HIFs are bound by the von Hippel-Lindau protein (VHL) in the cytosol where it is degraded by the proteasome, however, under hypoxia HIFs are translocated to the nucleus where they activate survival signals.

Survivin (BRIC5) is an inhibitor of apoptosis that also promotes cellular adaptation under stressful conditions and helps to regulate cell division. Recently, an antibody study by Dr. H Wang et al. at Brown University [PMID: 20826784] found that Survivin is acetylated at lysine residue 129, thereby affecting its subsequent subcellular localization.