This invention is based on the discovery that genetic restoration of p53 activity effectively cleared tumorigenic cells in a mouse model of human adenocarcinoma. Tumor cell destruction is orchestrated by the immune system’s natural killer cells (NK), which upregulate the expression of the cell surface marker, CD80, in response to p53 activation. This invention uses anti-CD80 antibodies to monitor the status of p53 activity when DNA damage response or other cellular stress related mechanisms are activated.
Cell surface expression of CD80 in response to p53 action is of potential clinical relevance. For instance, the induction of CD80 upon p53 action makes CD80 a useful biomarker for chemotherapeutic success. In addition, cell surface localization of CD80 allows antibody-mediated therapies to specifically target cancer cells with an activated p53 program.