Caspase-8

Cancer Res. 2008 Jun 15;68(12):4491-3.
Links
Caspase-8: fly or die.
Frisch SM.
West Virginia University, Mary Babb Randolph Cancer Center, Morgantown, West Virginia, USA. sfrisch@hsc.wvu.edu
Recent studies have revealed that procaspase-8 has an important function in cell adhesion and motility. Src phosphorylation controls this function by preventing the conversion of procaspase-8, which is an adhesion/migration factor, to mature caspase-8, which is an apoptosis-inducing factor. This provides a mechanism to switch these opposing functions. In its migratory role, procaspase-8 interacts with the phosphatidylinositol-3-OH kinase regulatory subunit p85alpha and c-src to modulate signaling by Rac and extracellular signal-regulated kinase, and promote calpain activation. Here, I survey the findings of these studies and discuss potential mechanisms and ramifications for cancer prognosis and therapy.
PMID: 18559490 [PubMed - in process]

Cancer Res. 2007 Dec 15;67(24):11505-9.
Links
Caspase-8 interacts with the p85 subunit of phosphatidylinositol 3-kinase to regulate cell adhesion and motility.
Senft J, Helfer B, Frisch SM.
Mary Babb Randolph Cancer Center, West Virginia University, Morgantown, West Virginia 26506, USA.
Cell migration plays an important role in tumor cell invasion and metastasis. Previously, we reported that caspase-8 contributes to cell migration and adhesion, a novel nonapoptotic function of an established apoptotic factor. Herein, we report that pro-caspase-8 is capable of restoring cell migration/adhesion to caspase-8-null cells, establishing the first biological function of a pro-caspase. The catalytic activity of caspase-8 was not required for cell motility. Stimulation of motility with epidermal growth factor induced the phosphorylation of caspase-8 on tyrosine-380 and the interaction of caspase-8 with the p85 alpha subunit of phosphatidylinositol 3-kinase. Tyrosine-380 was required for the restoration of cell motility and cell adhesion in caspase-8-null cells, demonstrating the importance of the caspase-8-p85 interaction for these nonapoptotic functions. These results suggest that caspase-8 phosphorylation converts it from a proapoptotic factor to a cell motility factor that, through tyrosine-380, interacts with p85, an established cell migration component.
PMID: 18089778 [PubMed - indexed for MEDLINE]