capecitabine and streptozotocin+/- cisplatin in advanced gastroenteropancreatic neuroendocrine tumours

Background: Cytotoxic chemotherapy is widely used for advanced, unresectable pancreatic and other gastrointestinal foregut neuroendocrine tumours (NETs) and the most commonly used regimen combines 5-fluorouracil with streptozocin. The NET01 trial was designed to investigate whether capecitabine combined with streptozocin was an acceptable regimen with or without adding cisplatin. Methods: Patients with advanced, unresectable NETs of pancreatic, gastrointestinal foregut or unknown primary site were randomised to receive three-weekly capecitabine (Cap) 625 mg/m(2) twice daily orally, streptozocin (Strep) 1.0 g/m(2) intravenously on day 1, with or without cisplatin (Cis) 70 mg/m(2) intravenously on day 1. The primary outcome measure was objective response. Secondary outcome measures included progression-free and overall survival, quality of life, toxicity and biochemical response. Results: 86 (44 CapStrep, 42 CapStrepCis) patients were randomised. Best objective response rate was 12% (95% confidence interval (CI) = 2-22%) with CapStrep and 16% (95% CI = 4-27%) with CapStrepCis. Disease-control rate was 80% with CapStrep and 74% with CapStrepCis. The estimated median progression-free and overall survival were 10.2 and 26.7 months for CapStrep and 9.7 and 27.5 months for CapStrepCis. 44% of CapStrep and 68% of CapStrepCis patients experienced grade >= 3 adverse events. Interpretation: The efficacies of the novel CapStrep +/- Cis regimens were very similar. CapStrep was better tolerated than CapStrepCis. The trial was registered as EudraCT: 2004-005202-71 and ISRCTN: 35124268. (C) 2014 Elsevier Ltd. All rights reserved

Structure of the heterodimeric core primase.

Primases are DNA-dependent RNA polymerases that synthesize the oligoribonucleotide primers essential to DNA replication. In archaeal and eukaryotic organisms, the core primase is a heterodimeric enzyme composed of a small and a large subunit. Here we report a crystallographic and biochemical analysis of the core primase from the archaeon Sulfolobus solfataricus. The structure provides the first three-dimensional description of the large subunit and its interaction with the small subunit. The evolutionary conservation of amino acids at the protein-protein interface implies that the observed mode of subunit association is conserved among archaeal and eukaryotic primases. The orientation of the large subunit in the core primase probably excludes its direct involvement in catalysis. Modeling of a DNA-RNA helix together with structure-based site-directed mutagenesis provides insight into the mechanism of template DNA binding and RNA primer synthesis

Extra-chromosomal elements and the evolution of cellular DNA replication machineries.

DNA replication is fundamental to the propagation of cellular life. Remarkably, the bacterial replication machinery is distinct from that used by archaea and eukaryotes. In this article, we discuss the role that lateral gene transfer by extra-chromosomal elements might have had in shaping the replication machinery and even modulating the manner in which host cellular genomes are replicated