Development of a Validated High Throughput ELISA Assay for γ-H2AX as a Pharmacodynamic Marker

Histone H2AX is a 14 kDa ubiquitous member of the H2A histone family that becomes rapidly phosphorylated at Serine 139 by ATM and ATR kinases to yield a form known as γ-H2AX in response to double-strand DNA damage and apoptosis. -H2AX is an ideal Pharmacodynamic (PD) surrogate marker to measure molecular responses to a large number of drugs; however, methods such as western blots and immunohistochemistry are widely used but are difficult to validate to regulatory standards, and not suitable for high throughput screening applications. To address this need, AMSBio have developed a novel high throughput ELISA assay to measure γ-H2AX levels in cellular extracts and phosphorylation of H2AX in response to therapeutic intervention. This assay documents differences of -H2AX levels in PBMC, cultured cells, tissue biopsies, and will be useful in future clinical trials providing one of many needed tools to enable hypothesis driven preclinical drug design strategies.