A novel human AP endonuclease with conserved zinc-finger-like motifs involved in DNA strand break responses

DNA damage causes genome instability and cell death, but many of the cellular responses to DNA damage still remain elusive. We here report a human protein, PALF (PNK and APTX-like FHA protein), with an FHA (forkhead-associated) domain and novel zinc-finger-like CYR (cysteine–tyrosine–arginine) motifs that are involved in responses to DNA damage. We found that the CYR motif is widely distributed among DNA repair proteins of higher eukaryotes, and that PALF, as well as a Drosophila protein with tandem CYR motifs, has endo- and exonuclease activities against abasic site and other types of base damage. PALF accumulates rapidly at single-strand breaks in a poly(ADP-ribose) polymerase 1 (PARP1)-dependent manner in human cells. Indeed, PALF interacts directly with PARP1 and is required for its activation and for cellular resistance to methyl-methane sulfonate. PALF also interacts directly with KU86, LIGASEIV and phosphorylated XRCC4 proteins and possesses endo/exonuclease activity at protruding DNA ends. Various treatments that produce double-strand breaks induce formation of PALF foci, which fully coincide with γH2AX foci. Thus, PALF and the CYR motif may play important roles in DNA repair of higher eukaryotes

FOLFIRINOX – a new paradigm in the treatment of pancreatic cancer

Treatment of metastatic and locally advanced pancreatic cancer has made slow progress during the last decade. Single agent gemcitabine or in combination with capecitabine or erlotinib remained the preferred systemic treatment options until 2010 when the ACCORD study demonstrated significantly improved outcomes achieved with FOFIRINOX compared with gemcitabine monotherapy. Since 2010, use of FOLFIRINOX has increased both in metastatic and locally advanced cancer. Despite its gaining popularity among oncologists, unanswered questions remain. Do the often necessary dose modifications affect its efficacy? Are the toxicities manageable and how applicable are the results of the ACCORD study in the general population of patients with newly diagnosed pancreatic cancer? In the present manuscript, we review the published literature regarding the use of FOLFIRINOX, the challenges associated with its use and how it will be optimally incorporated into the management of patients with different stages of pancreatic cancer and ultimately, in a more biomarker-driven pathway algorithm.</p