PARP1 expression in mantle cell lymphoma: the utility of PARP1 immunohistochemistry and its relationship with markers of DNA damage.

Mantle cell lymphoma (MCL) is an aggressive disease with poor overall survival, attributable in part to frequent defects of the DNA repair genes. In such malignancies, additional inhibition of the ubiquitous DNA damage repair protein, poly-ADP ribose polymerase-1 (PARP1) has shown enhanced cytotoxicity (so-called synthetic lethality). We studied PARP1 expression in a series of clinical cases of MCL, with the secondary aim to ascertain the relationship between PARP1 expression and DNA repair gene expression (namely ATM and p53) by immunohistochemical methods.